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compositional-format-following

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summarization_eval

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CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation application of U.S. application Ser. No. 15/131,624, filed Apr. 18, 2016, which is a continuation application of U.S. application Ser. No. 14/179,889, filed Feb. 13, 2014, and claims priority to U.S. Provisional Application No. 61/764,281, filed Feb. 13, 2013, the entire contents of each of which are incorporated herein by reference. BACKGROUND The present invention relates to aquarium lighting. More particularly, the present invention relates to aquarium lighting using LEDs. Residential aquarium keeping is a mature and established industry in the United States and around the world. A basic version of an aquarium includes a transparent container for aquatic life to be viewed and housed within. These containers are typically constructed of either glass or a transparent plastic material such as acrylic or polystyrene, but may be made of other transparent or semi-transparent materials. Basic aquatic environments of this nature are limited in their ability to sustain suitable conditions and water quality for all but a handful of robust and hearty fish. Often more appropriate for the health and well-being of the aquatic organisms is the addition of filtration, lighting, oxygenation, temperature control, chemical and biological balance. SUMMARY In accordance with one construction, a light member includes a housing having a top side and a bottom side, the top side facing away from an interior of the aquarium, and the bottom side facing the interior of the aquarium. The light member also includes a lighting control region disposed on the bottom side of the housing. The lighting control region includes a first control channel associated with a first color of light, a second control channel associated with a second color of light, and a neutral channel, the lighting control region being sized to receive one or more light-emitting modules. The light member also includes a switch coupled to the housing, the switch operable to control the first control channel. In accordance with another construction, a light member includes a housing having a top side and a bottom side, and a lighting control region disposed on the bottom side of the housing. The lighting control region includes a first control channel, a second control channel, and a neutral channel disposed therein. The light member also includes a first light-emitting module sized and configured to be coupled to the lighting control region, the first light-emitting module having an LED that emits a first color of light, the first light-emitting module further having a first electrical connector that couples to the first control channel. The light member also includes a second light-emitting module sized and configured to be coupled to the lighting control region, the second light-emitting module having an LED that emits a second color of light, the second light-emitting module further having a second electrical connector that couples to the second control channel. In yet another construction, a light member includes a housing having a top side and a bottom side. The top side faces away from a space to be lit, and the bottom side faces the space to be lit. A lighting control region is disposed on the bottom side of the housing that illuminates the space and has a first control channel, a second control channel, and a neutral channel. A first light-emitting module is electrically connected to the first control channel and the neutral channel and a second light-emitting module is electrically connected to the second control channel and the neutral channel. A switch assembly is coupled to the housing and is operable to selectively deliver power to the first control channel and the second control channel. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a light member according to one construction. FIG. 2 is a perspective view of the light member of FIG. 1 , illustrating a lighting control region along a bottom of the light member. FIG. 3 is an enlarged perspective view of the lighting control region. FIG. 4 is a bottom view of a light-emitting module according to one construction. FIG. 5 is a top view of the light-emitting module of FIG. 4 , illustrating two electrical connectors. FIG. 6 is a bottom view of a light-emitting module according to another construction. FIG. 7 is a top view of the light-emitting module of FIG. 6 , illustrating two electrical connectors. FIG. 8 is an exploded perspective view of the light-emitting module of FIG. 6 . FIG. 9 is a perspective view of a light member according to another construction, illustrating two lighting control regions along a bottom of the light member. FIG. 10 is a perspective view of a radio frequency (RF) light-emitting module according to another construction, along with a remote control for operating the light-emitting module. FIG. 11 is a schematic illustration of a dual in-line timer for a light-emitting module. FIG. 12 is a schematic illustration of a single in-line timer for a light-emitting module. FIG. 13 is a schematic illustration of a cabinet and mounting bracket for insertion of the light member. FIG. 14 is a schematic illustration of a series of the light members mounted under a cabinet. FIGS. 15 and 16 are schematic illustrations of an optical element being added to a light member under a cabinet. DETAILED DESCRIPTION FIGS. 1-3 illustrate a light member 10 that includes a housing 14 having a top side 18 and a bottom side 22 . The housing 14 is an elongate, generally rectangular component sized and configured to fit over and couple to another structure such as an aquarium. When coupled to an aquarium, the top side 18 faces up and away from an interior of an aquarium, and the bottom side 18 faces down and into the interior of the aquarium to provide lighting inside the aquarium. As illustrated in FIGS. 1 and 2 , the housing 14 includes clips 24 for releasably coupling the housing 14 to the aquarium. Other constructions include different structures for coupling the housing 14 to the aquarium or to another structure. In some constructions the housing 14 has other shapes and sizes than that illustrated. With reference to FIGS. 2 and 3 , the bottom side 22 includes a lighting control region 26 . In the illustrated construction the lighting control region 26 includes a groove that extends generally linearly in an elongate direction along the bottom side 22 , and includes a first control channel 30 , a second control channel 34 , and a third, neutral channel 38 disposed therein. The third channel 38 is disposed between the first and second channels 30 , 34 . The first and second channels 30 , 34 are control channels for controlling two different sets of light within the aquarium. In the illustrated construction the channel 30 controls white light, and the channel 34 controls blue light. While the illustrated light member 10 includes two control channels, in other constructions more than two control channels (e.g., three, four, five, ten, twenty, etc.) are used. Each of the control channels 30 , 34 can be controlled independently of the other control channel 30 , 34 . In the illustrated construction, the control channel 30 is used primarily as a “daylight” channel for emitting higher intensity white light, while the control channel 34 is used primarily as a “night” channel for emitting lower intensity blue light. With reference to FIGS. 1 and 3 , the light member 10 includes a switch 42 on the housing 14 that is coupled to the control channel 30 , and a switch 46 on the housing 14 that is coupled to the control channel 34 . The switch 42 is an on/off switch, and the switch 46 is a dimmer style on/off switch. Of course, the switch types could be reversed or both switches could be on/off switches or dimmer switches as may be desired. In some constructions a single switch is used instead of the two switches 42 , 46 . In another construction, a three way switch is employed to allow a single switch to control both channels 30 , 34 . In the three way switch construction, the switch is typically arranged with a first position in which neither channel 30 , 34 received power. The switch is then movable to a second position in which power is delivered only to the first channel 30 or a third position in which power is delivered only to the second channel 34 . In a preferred arrangement, the switch is arranged with a middle position corresponding to the first position, The switch is then movable in opposite directions to the second position or the third position. A single power cord 48 is coupled to the housing 14 to provide electrical power to both the control channel 30 and the control channel 34 . In some constructions the light element 10 also includes a built-in transformer. Use of the two control channels 30 , 34 to control white and blue light enables an end user to define a color temperature output of the aquarium. If the control channel 30 is a relatively warm color temperature, by adding blue light from the control channel 34 with the dimmer switch 46 the user is able to modify a blended color temperature, making the blended color temperature bluer and therefore cooler. It should be noted that while a blue light is described herein, virtually any other color could also be provided. For example, the light could be red, green, yellow, or virtually any other color desired. In the illustrated construction, the blended color temperature is adjustable between a range of 3500K to 15,000K. In some constructions the temperature is adjustable between 5000K to 12,000K. Other constructions include different temperature ranges. When the control channel 30 is turned off, the control channel 34 functions to provide a night mode for the aquarium. This two channel design enables variable functionality and output options in a small and focused footprint (i.e., within the lighting control region 26 ), which is a desirable feature in aquarium lighting. In this way, a broad range of user functionality is built into a simple, manually controllable design. With reference to FIGS. 2-8 , the light member 10 also includes one or more light-emitting modules 50 , 54 that are releasably coupled to the lighting control region 26 and to one of the channels 30 , 34 , to emit the white or blue light. The modules 50 , 54 can be positioned anywhere along the lighting control region 26 . A single module 50 , 54 , or multiple modules 50 , 54 , may be added to or removed from the light member 10 at various locations along the lighting control region 26 as desired. As illustrated in FIGS. 2-8 , each of the modules 50 , 54 includes a tab 58 that releasably couples the modules 50 , 54 to a protrusion 60 on the lighting control region 26 . Other constructions include different structures to releasably couple the modules 50 , 54 to the lighting control region 26 . However, the tab 58 , or other structure are preferably arranged so that the light-emitting modules can only be installed into the lighting control region 26 in one orientation. The tab 58 is formed as part of the module 50 , 54 and includes a living hinge that allows for movement of the tab 58 with respect to the remainder of the module 50 , 54 . When the tab 54 is depressed toward the remainder of the module 50 , 54 the user is able to insert, remove, or move the module 50 , 54 along the lighting region 26 . When the tab 54 is released, the living hinge biases the tab 54 into engagement with the protrusion 60 to firmly retain the module 50 , 54 in the desired position and in electrical contact with one or both of the channels 30 , 34 and the neutral 38 . With reference to FIGS. 4 and 5 , in the illustrated construction each of the modules 50 includes a bottom side 62 that faces the interior of the aquarium, and a top, connection side 66 that faces the lighting control area 26 . Four LEDs 70 are disposed along the bottom side 62 . In some constructions, different numbers and positions of LEDs 70 are arranged along the bottom side 62 . In some constructions, the modules 50 have shapes other than that illustrated. The four LEDs 70 of the module 50 are configured to emit white light with other colors being possible. With reference to FIG. 5 , the connection side 62 of the module 50 includes a first electrical connector 74 and a second electrical connector 78 . When the module 50 is coupled to the lighting control area 26 , the first electrical connector 74 couples to the control channel 30 , and the second electrical connector 78 couples to the neutral channel 38 , to provide electrical power through the channel 34 to the module 50 and the LEDs 70 . The electrical connectors 74 , 78 are metal tabs disposed along the connection side 66 that extend outward slightly to engage the channels 30 , 38 and form electrical connections. With reference to FIGS. 6 and 7 , in the illustrated construction each of the modules 54 includes a bottom side 82 that faces the interior of the aquarium, and a top, connection side 86 that faces the lighting control area 26 when coupled to the light member 10 . Four LEDs 90 are disposed along the bottom side 82 . In some constructions different numbers and positions of LEDs 90 are arranged along the bottom side 82 . In some constructions the modules 54 have shapes other than that illustrated. The four LEDs 90 of the module 54 are configured to emit blue light. With reference to FIG. 7 , the connection side 86 of the module 54 includes a first electrical connector 94 and a second electrical connector 98 . When the module 54 is coupled to the lighting control area 26 , the first electrical connector 94 couples to the control channel 34 , and the second electrical connector 98 couples to the neutral channel 38 , to provide electrical power through the channel 34 to the module 54 and the LEDs 90 . The electrical connectors 94 , 98 are metal tabs disposed along the connection side 86 that extend outward slightly to engage the channels 34 , 38 and form electrical connections. As illustrated in FIGS. 5 and 7 , the electrical connector 74 is disposed farther away from the tab 58 than the electrical connector 94 . This arrangement, in combination with the arrangement of the light-emitting module that only allows installation in one orientation assures that the connector 74 is only able to electrically connect to the channel 30 . With reference to FIG. 8 , each of the modules 54 (and similarly each of the modules 50 ) includes a bottom side cover plate 102 that fits over the LEDs 90 (or the LEDs 70 ), a printed circuit board (PCB) 106 that is coupled to both the LEDs 90 (or the LEDs 70 ) and the electrical connectors 90 , 94 (or the electrical connectors 74 , 78 ), and a connection side cover plate 110 that is coupled to the electrical connectors 90 , 94 (or the electrical connectors 74 , 78 ). As illustrated in FIG. 8 , the cover plate 110 includes two hollowed-out bosses 114 and two openings 116 adjacent the hollowed-out bosses 114 in the cover plate 110 that receive portions of the electrical connectors 94 , 98 . The electrical connectors 94 , 98 are biased toward the cover plate 110 and the openings 116 by springs 118 that are coupled at first ends 122 to the PCB 106 and at opposite ends 126 to the electrical connectors 94 , 98 . The electrical connectors 94 , 98 include circumferentially extending protrusions 130 that act as stops to engage inner surfaces 134 of the bosses 114 and limit the extent to which the connectors 94 , 98 are biased away from the PCB 106 . The electrical connectors 94 , 98 also include contact ends 138 that extend adjacent the protrusions 130 and are received in the openings 116 . The contact ends 138 extend through the openings 116 and engage one or more of the channels 30 , 34 , 38 . When the electrical connectors 94 , 98 , (or the electrical connectors 74 , 78 ) contact and engage one or more of the channels 30 , 34 , 38 , the springs 118 press the connectors 94 , 98 away from the PCB 106 and press the contact ends 138 into contact with the channels 30 , 34 , 38 to assure a good electrical connection. In some constructions a single module is used in place of the separate modules 50 , 54 . The single module emits both white and blue light (e.g., with various LEDs), and is coupled to both control channels 30 , 34 . A manual intensity control is provided on a bottom side, for example, of the single module to fine tune color temperature emitting from the single module. In some constructions one or more of the modules 50 , 54 include narrow incident angle LEDs 70 , 90 that are able to be rotated or are otherwise able to be have their light directed toward a focal point or points within an aquarium. In some constructions one or more of the modules 50 , 54 incorporate wide angle LED's 70 , 90 for a “flood” light effect. In some constructions one or more of the modules 50 , 54 include optical elements (e.g., lenses, etc.) that change angles of the light emitted from the LEDs 70 , 90 , diffuse the light, and/or focus the light. In some constructions the optical elements are removable. The optical elements are removable while the light element 10 is in place (e.g. while the light element 10 is coupled to an aquarium). In some constructions the optical elements snap onto the modules 50 , 54 . In some constructions, one or more of the modules 50 , 54 include just one LED color temperature (e.g., all white or all blue) or a combination of LED types for a desired effect in the aquarium. In some constructions one or more of the modules 50 , 54 include a multitude of different LED types other than just blue and white LEDs, such as red/white or others. In some constructions one or more of the modules 50 , 54 are heat-sinked so as to be able to modulate temperatures at the diode levels or include mechanical couplings such that the heat sinks for the LED modules are contained in the light element 10 itself rather than within the modules 50 , 54 . With reference to FIG. 8 , each module 50 (and similarly each module 54 ) has a thickness 142 , as measured in a direction between the top and bottom sides 62 , 66 , and perpendicular to both the top and bottoms sides 62 , 66 , of less than approximately 1.0 inch. In some constructions the thickness 142 is approximately 0.75 inch. Other constructions include different thicknesses for the modules 50 , 54 . With continued reference to FIGS. 4-7 , each module 50 (and similarly each module 54 ) is square, and has both a width and a height 146 (not including the tabs 58 ) of approximately 3.75 inches. In some construction the width and the height 146 are both approximately 2.25 inches. In some constructions both the width and the height 146 are less than approximately 4 inches. Other constructions include different widths and heights for the modules 50 , 54 , as well as different shapes for the modules 50 , 54 . FIG. 9 illustrates a light member 210 that is similar to the light member 10 , and includes a housing 214 having a bottom side 222 facing an interior of the aquarium. The bottom side 222 includes two lighting control regions 226 . The lighting control regions 226 extend generally linearly in an elongate direction parallel to one another, and include a first control channel 230 , a second control channel 234 , and a third, neutral channel 238 disposed therein. The third channel 238 is disposed between the first and second channels 230 , 234 . As with the light member 10 , the channels 230 and 234 are control channels for controlling two different types of light within the aquarium. The same channels 230 , 234 , and 238 run through both of the lighting control regions 226 , and are controlled by switches 242 , 246 . In some constructions each lighting control region 226 instead includes a separate set of control channels 230 , 238 and a neutral channel 234 , with one or more switches operable to control the channels 230 , 234 , 238 within each lighting control region 226 . Each of the lighting control regions 226 provides room for coupling of one or more modules (e.g., such as modules 50 , 54 ). In other constructions more than two lighting control regions 226 are provided. In some constructions, a light member includes two lighting control regions that are coupled to dimmer switches for controlling blue light, and a single lighting control region disposed between the two lighting control regions that is coupled to an on/off switch for controlling white light. Various other combinations of lighting control regions and modules are also possible. FIG. 10 illustrates a module 350 that includes radio frequency (RF) or other communication/control hardware so as to be controlled remotely by a remote control 352 . Typically, the module 350 or other component, such as the light member includes an RF receiver that can receive an RF signal for use in controlling the module 350 . In this manner the control channels 30 , 34 , 230 , 234 on the lighting control region 26 , 226 supply power to the module 350 , but the color, intensity and other functionality are controlled remotely by the remote control 352 . The module 350 includes six LEDs 370 . In the illustrated construction each of the LEDs 370 is an RGB LED that is capable of emitting varying levels of red, green, or blue light. The RGB LEDs 370 blend red, green, and blue light to create a wide range of colors within the aquarium. When coupled to the light-emitting region 26 , 226 , the module 350 receives power from the control channel 30 , 34 , 230 , 234 and is controlled remotely by an RF signal from the remote control 352 . In some constructions multiple modules 350 are coupled to the lighting control region 26 , 226 , with each of the modules 350 being controlled by a single remote control 352 . The remote control 352 functions include on/off, increase/decrease intensity, color selection, reset (to white light), and auto mode where the module 350 continuously cycles through the different colors. The module 350 also includes inputs 372 for insertion of one or more optics to snap onto the module 350 that change an angle of emitted light from the LEDs 370 , or otherwise alter and affect the optics and emission of light from one or more of the LEDs. FIG. 11 schematically illustrates a light member 410 that is controlled with two in-line timers 456 , 460 . The timer 456 is coupled to a first control channel 430 , and the timer 460 is coupled to a second control channel 434 . The first and second control channels 430 , 434 control white and blue light (or other arrangements), similar to the channels 30 , 34 , and 230 , 234 described above. Each of the timers 456 , 460 is coupled to a transformer 464 , 468 , respectively, and the transformers 464 , 468 are coupled to either a single power cord 448 or multiple power cords 448 . As illustrated in FIG. 9 , the timers 456 , 460 , are slim, elongate structures that emphasize an “in-line” application with the power supply cord or cords 448 . The in-line timers 456 , 460 are digital controllers. The timers 456 , 460 allow a user to set a time limit for various colors emitting from one or more modules (e.g., modules 50 , 54 , 250 , 254 , 350 , etc.) coupled to the light member 410 , and are programmable to set on/off times and to gradually ramp power up/down by varying the DC voltage, thereby creating a dimming effect. The timers 456 , 460 also have various mode settings allowing a user to manually select an on/off, a timer mode, and a demo/preview mode to preview current settings. FIG. 12 illustrates a single timer 556 that controls both channels 430 , 434 , and is coupled to a single transformer 564 . The timer 556 is also a slim, elongate structure that emphasizes an “in-line” application with the power supply cord 448 . Depending on the application, one or more of the timers 456 , 460 , 556 may be used to control a single channel or multiple channels, setting specific on/off times and/or dimming duration for each channel. While the light members described above are described in the context of an aquarium, the light members may be used with various other types of enclosures and structures, including underneath office or kitchen cabinets to provide lighting beneath the cabinets. For example, and with reference to FIGS. 13-16 , in some constructions a cabinet 600 includes a bracket 602 that provides a structure by which a light member 610 is coupled to the cabinet 600 . The light member 610 may be mounted first to the bracket 602 , or the bracket may first be mounted to the cabinet 600 . The light member 610 may be identical to one of the light members described above, such as light member 10 , or may include different features or structures other than that illustrated for light member 10 . With reference to FIG. 14 , in some constructions the light member 610 is coupled together with other light members 610 to provide for a series of light members 610 disposed underneath one or more cabinets. A power cord 648 is disposed at one end of one of the light members 610 , and a connector cord 649 is coupled at the opposite end, so as to link together two or more light members 610 in series. As illustrated in FIG. 14 , a transformer 664 is additionally provided in conjunction with and coupled to the power cord 648 . The transformer 664 is mountable to the bottom of the cabinet 600 . One of the light members 610 includes a plug 670 in place of a connector cord 649 . With continued reference to FIGS. 13-16 , the light member 610 includes switches 642 , 646 (similar to switches 42 , 46 ) that are disposed along either a side ( FIG. 13 ) or bottom ( FIG. 14 ) of the light member 610 , to provide for accessible control of one or more modules (e.g., modules 50 , 54 ) on the light member 610 . In some constructions, the modules (or lighting control regions) for the light member 610 are of different size or shape than the modules (or lighting control regions) for the light member 10 , such that the modules for the light member 610 are only for use underneath a cabinet in the lighting member 610 , and the modules for the light member 10 are only for use with an aquarium on the lighting member 10 . With reference to FIGS. 15 and 16 in some constructions the light member 610 also includes an optics member 674 (e.g., a lens, a diffuser, etc.) that is coupled along a bottom side 622 of the light member 610 either by sliding the optics member 674 along the bottom side 622 in a generally horizontal direction parallel to the bottom side 622 ( FIG. 15 ) or by raising the optics member 674 up to the bottom side 622 and snapping or otherwise coupling the optics 674 in place over the bottom side 622 (and over, for example, one or more modules on the light member 610 ). Various features and advantages of the invention are set forth in the following claims.

A light member includes a housing having a top side and a bottom side. The top side faces away from a space to be lit, and the bottom side faces the space to be lit. A lighting control region is disposed on the bottom side of the housing that illuminates the space and has a first control channel, a second control channel, and a neutral channel. A first light-emitting module is electrically connected to the first control channel and the neutral channel and a second light-emitting module is electrically connected to the second control channel and the neutral channel. A switch assembly is coupled to the housing and is operable to selectively deliver power to the first control channel and the second control channel.

big_patent

TECHNICAL FIELD [0001] The present invention relates to the field of thermal machines. It relates in particular to a cooled flow deflection apparatus for a fluid-flow machine which operates at high temperatures, as claimed in the precharacterizing clause of claim 1 . [0002] Such a flow deflection apparatus is generally known from the prior art, for example in the form of a cooled stator blade or rotor blade for a gas turbine. PRIOR ART [0003] Present-day flow deflection apparatuses, especially stator blades or rotor blades in a gas turbine, are subjected to ambient temperatures which are above the maximum permissible material temperature. The use of special internal cooling channels allows the metal temperature to be reduced to a level which is required on the basis of the life of the apparatus. [0004] [0004]FIGS. 1 and 2 respectively show a cross section and longitudinal section of an example of a rotor blade of a gas turbine, as is currently used. The blade 10 essentially comprises a blade airfoil section 11 and a blade root 12 , by means of which it is attached to the rotor of the gas turbine. A number of cooling channels 17 run in the longitudinal direction of the blade 10 in the interior of the (hollow) blade airfoil section 11 , through which cooling channels 17 a cooling fluid, generally cooling air which enters through the blade root 12 , flows. The cooling fluid runs, with a cooling effect, in the cooling channels 17 along the insides of the hot-gas walls 14 and then (for film cooling) emerges to the outside through appropriate film-cooling openings which are arranged on the leading edge 18 , on the trailing edge 19 and at the blade tip (the emerging cooling fluid is indicated by the arrows in FIG. 2). The individual cooling channels 17 are separated from one another by separating walls 13 which at the same time have deflection devices 16 to ensure that the cooling fluid flows successively through adjacent cooling channels in alternately opposite directions. [0005] Until now, and in this case specifically in the case of rotating guide apparatuses such as rotor blades, the cooling channels 17 and their separating walls 13 have been cast. [0006] The known, cast separating walls 13 and deflection devices 16 , which are also referred to as ribs, have a number of disadvantages, however: [0007] The transitional region ( 15 in FIG. 1) from the hot-gas wall 14 to the separating wall (rib) 13 is an area which is difficult to cool owing to the large amount of material in that area. Increased heat transfer together with increased cooling-air consumption is required in order to ensure adequate strength there. [0008] The cold separating walls (ribs) 13 , around which the cooling air flows, lead to thermal stresses with the hot-gas wall 14 . [0009] Casting of the internal channels leads to a high blade weight, which can lead to high centrifugal-force stresses both for the blade root 12 and for the blade airfoil section 11 . [0010] The complex casting lengthens casting development and increases the amount of scrap. DESCRIPTION OF THE INVENTION [0011] The object of the invention is thus to provide a cooled flow deflection apparatus which avoids the described disadvantages of the known apparatus and in particular is simple to produce, can be flexibly matched to the respective application, and is efficiently cooled. [0012] The object is achieved by the totality of features of claim 1 . The essence of the invention is no longer to produce, in particular to cast, the separating walls, which are used to bound the cooling channels, jointly with the apparatus, but to construct them as separate inserts which are subsequently inserted into the apparatus, and are secured there. The invention is thus considerably different to solutions such as those described in U.S. Pat. No. 5,145,315 or U.S. Pat. No. 5,516,260, in which specific inserts in cast cooling channels are used for specific guidance of the cooling fluid. [0013] The use of inserts (for example, in the case of blades, inserted through the blade root or through the blade tip) composed of metal or non-metal materials as a substitute for cast separating walls and, possibly, deflection devices, has a number of advantages: [0014] There is no large amount of material in the transitional region from the hot-gas wall to the insert (to the separating wall). [0015] There are no thermal stresses between the insert (separating wall) and the hot-gas wall. [0016] In the case of rotating blades, the blade weight and thus the centrifugal-force stresses are reduced both in the blade root and in the blade airfoil section. [0017] In the case of cast blades, the cast core is simpler, as a result of which both its capability to be produced and that of the blade are simpler. [0018] The cooling system can easily be adjusted by replacing the inserts, for example by varying the deflection radius of deflection devices or by introducing connecting cross sections between two cooling channels. [0019] A first preferred embodiment of the flow deflection apparatus according to the invention is characterized in that the flow deflection apparatus is in the form of a hollow casting, and in that holders, which are in the form of rails and into which the separating walls are inserted, are integrally formed in the interior of the flow deflection apparatus. This considerably simplifies assembly and attachment of the inserts, and ensures that the separating walls or inserts are sealed well at the edges. The separating walls are in this case preferably flat strips composed of a metallic or heat-resistant non-metallic (ceramic or composite) material. [0020] A secure seating for the inserts is achieved if, according to a second preferred embodiment of the invention, the inserted separating walls are, for security, connected by an integral material joint, preferably by soldering or welding, to the flow deflection apparatus. [0021] In the simplest form, the separating walls may be straight. [0022] It is particularly simple and advantageous if, according to another embodiment, the cooling fluid flows in mutually opposite directions in two adjacent cooling channels, if the cooling fluid is deflected from the outlet of the one cooling channel into the inlet of the other cooling channel by means of a deflection device, and if the deflection is produced by a separating wall which is bent into a U-shape. [0023] One particularly preferred embodiment of the flow deflection apparatus according to the invention is characterized in that the flow deflection apparatus is a blade in a gas turbine. Owing to the comparatively complex geometry of the blade, the invention in this case results in considerable simplifications. [0024] Another embodiment, which is particularly advantageous for rotor blades which rotate at high speed, is characterized in that the cooling channels and separating walls extend essentially in the radial direction with respect to the rotation axis of the gas turbine, in that the inserted separating walls are, for security, connected by an integral material joint, preferably by soldering or welding, to the blade, and in that the integral material joint is arranged at the end of the separating walls close to the axis. BRIEF DESCRIPTION OF THE FIGURES [0025] The invention will be explained in more detail in the following text with reference to exemplary embodiments and in conjunction with the drawing, in which: [0026] [0026]FIG. 1 shows the cross section through a turbine blade having cast cooling channels according to the prior art; [0027] [0027]FIG. 2 shows a longitudinal section through the blade shown in FIG. 1; [0028] [0028]FIG. 3 shows a cross section, comparable to that in FIG. 1, through a blade according to one exemplary embodiment of the invention; and [0029] [0029]FIG. 4 shows a longitudinal section, comparable to that in FIG. 2, through the blade shown in FIG. 3. APPROACHES TO IMPLEMENTATION OF THE INVENTION [0030] [0030]FIGS. 3 and 4 respectively show a cross section and longitudinal section of an exemplary embodiment of a cooled flow deflection apparatus according to the invention in the form of a rotor blade for a gas turbine. The geometry of the blade 20 is similar to that of the known blade 10 shown in FIGS. 1 and 2. [0031] Once again, the blade 20 essentially comprises a blade airfoil section 21 and a blade root 22 , by means of which it is attached to the rotor of the gas turbine. A number of cooling channels 27 , through which a cooling fluid which enters through the blade root 22 flows, run in the longitudinal direction of the blade 20 , in the interior of the (hollow) blade airfoil section 21 . The cooling fluid runs in cooling channels 27 along the insides of the hot-gas walls 24 , with a cooling effect, and in this case as well emerges to the outside through appropriate film cooling openings which are arranged on the leading edge 28 , on the trailing edge 29 , and at the blade tip. The individual cooling channels 27 are separated from one another by separating walls 23 which at the same time have deflection devices 26 to ensure that the cooling fluid flows successively through adjacent cooling channels in alternately opposite directions. [0032] In contrast to FIGS. 1 and 2, the separating walls 23 are in this case not cast, however, that is to say produced together with the blade 20 in one casting process, but are separate inserts, in the form of strips, which, once the blade 20 has been cast, are introduced through the blade root 22 or through the opposite blade tip. In order to allow the separating walls 23 to be inserted as required and to be secured after insertion, holders 30 which are in the form of rails and in which the longitudinal edges of the separating walls 23 are guided during insertion are integrally formed on the insides of the hot-gas walls. [0033] The separating walls (inserts) 23 may have any desired shape. For example, they may be straight. If a number of cooling channels are intended to be connected to one another by means of deflection devices 26 , it is advantageous for the separating walls 23 to be bent into a U-shape. The separating walls 23 can be secured on one or more sides, for example by soldering or welding. They may be fixed in the blade tip region or in the blade root region. The latter has the advantage that the centrifugal forces which occur load the insert or the separating wall in tension, thus preventing them from bulging out. [0034] In principle, the separating walls which can be inserted are provided at the same time that the blades are produced. However, it is also feasible within the scope of the invention for the cast separating walls subsequently to be removed from completely cast blades as shown in FIGS. 1 and 2 and for separate separating walls to be inserted and to be secured as a substitute for them. LIST OF REFERENCE SYMBOLS [0035] [0035] 10 , 20 Blade [0036] [0036] 11 , 21 Blade airfoil section [0037] [0037] 12 , 22 Blade root [0038] [0038] 13 Separating wall (rib) [0039] [0039] 14 , 24 Hot-gas wall [0040] [0040] 15 , 25 Transitional region [0041] [0041] 16 , 26 Deflection device [0042] [0042] 17 , 27 Cooling channel [0043] [0043] 18 , 28 Leading edge [0044] [0044] 19 , 29 Trailing edge [0045] [0045] 23 Insert [0046] [0046] 30 Holder (in the form of a rail)

Apparatus is disclosed for providing cooling channels in the interior of a gas turbine rotor blade. The cooling channels are formed by metallic inserts which extend from adjacent the root of the blade toward the tip. The inserts are substantially flat and are secured in the interior of the airfoil section by means of rails which engage the longitudinal edges of the inserts and serve as a guide during insertion. The rails are preferable formed integrally with the blade casting.

big_patent

BACKGROUND OF THE INVENTION The present invention relates generally to the field of fuel delivery devices, and more particularly, is directed to a system and method for effecting either automatic or manual control of a fuel delivery system for delivering a variable quantity of fuel to the engine of a power delivery apparatus. With the present emphasis in the automotive industry toward improving fuel economy and reducing exhaust emissions, there has been much research and development directed toward providing automatic systems for controlling the operation of a motor vehicle. Some of the research and development has focussed on systems for controlling the fuel delivered to the engine of the vehicle. One such system is disclosed in U.S. Pat. No. 4,424,785, issued in the name of Ishida et al. In this system, various parameters such as the degree of movement of the accelerator pedal, air flow within the engine intake bore and throttle valve position are provided to a control unit which compares these parameters with pre-programmed values to provide an optimum throttle valve setting for the engine. Should the control unit fail, however, the throttle cannot be controlled and the vehicle can not be run. Ishida recognized this deficiency and discloses an auxiliary control unit which assumes control over the throttle when the main control unit is out of order. When the main unit malfunctions, the auxiliary unit is immediately activated. The auxiliary unit, however, provides only limited throttle control, sufficient only to drive the vehicle at low speed to a service station to effect repair of the main unit. While the Ishida system represents an improvement over such systems known in the prior art, his system is also deficient. For example, in Ishida, the auxiliary control unit immediately assumes control of the throttle valve when the main unit malfunctions. No provisions are provided for returning the throttle valve to a predetermined position or ascertaining the position of the throttle valve so that control can be smoothly passed to the auxiliary unit. Thus, the vehicle may lurch forward or stall until the throttle valve setting matches the auxiliary control unit demand. Moreover, in the Ishida system, the auxiliary control unit provides only limited throttle operation. Thus, the vehicle may be operated only at low speeds until the main unit is repaired. Restricting the vehicle to low speed operation can be dangerous in some situations, as for example freeway driving. It can also be dangerous during routine city driving as well as traffic conditions often demand rapid acceleration. Thus, while Ishida represents an improvement over prior fuel delivery control systems, it is not the ideal system. SUMMARY OF THE INVENTION It is the overall object of the present invention to provide a system and method for controlling the operation of a fuel delivery system which can be switched between manual and automatic control. It is a specific object of the present invention to provide a system and method for controlling the operation of a fuel delivery system for a vehicle which can be smoothly switched between automatic and full manual control without causing the vehicle to lurch forward or stall. It is another specific object of the present invention to provide a system and method for controlling the operation of a fuel delivery system for a vehicle which, when under manual control, provides full operation of the vehicle. It is a further specific object of the present invention to provide a system for controlling the operation of a fuel delivery system for a vehicle which does not impair the safety of the vehicle driver or hamper the operation of the vehicle. The present invention relates to a system for automatically or manually controlling the operation of a fuel delivery system for a vehicle, as for example, a throttle valve. The system comprises a control unit which receives a signal indicating accelerator pedal position and a signal indicating the position of the throttle valve. These signals are processed to provide a control signal to a DC motor which automatically sets the throttle position for optimum performance of the venicle, as for example, to maintain the vehicle along its ideal operating line. The control unit also provides an output signal which controls a clutch. The clutch connects the accelerator pedal directly to the throttle valve when manual control is desired. During manual control, the vehicle driver has full control of the vehicle. Changing control from automatic to manual, however, does not occur until the throttle valve is moved either to a predetermined position or is positioned to match what is commanded by the accelerator pedal. Thus, the vehicle is prevented from lurching forward or stalling when control is shifted from automatic to manual. In accordance with the present invention, control of the throttle valve may be selected by the vehicle driver for automatic or manual control. It is anticipated that the throttle valve will normally be controlled by the automatic control unit until the unit malfunctions or some other fault is detected. Upon a malfunction or detection of a fault, the unit can be switched to manual control either at the command of the vehicle operator or as a result of the malfunction being detected by the automatic control unit itself and effecting a switch-over to manual control. It is also anticipated that the control system of the present invention may be used in conjunction with a system for controlling the operation of a continuously variable transmission as disclosed in applicant's pending and commonly assigned application Ser. Nos. 380,922 and 380,923 filed May 21, 1982, now U.S. Pat. Nos. 4,459,878 and 4,458,560, and which are incorporated herein by reference. At high transmission ratios, it is desirable to manually control the throttle valve position while at low transmission ratios, automatic control is preferred. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of the system for controlling the fuel delivery system of an engine in accordance with the present invention. FIG. 2 is a flow chart illustrating a computer subroutine used to generate pulses for driving a DC stepper motor in accordance with the present invention. FIG. 3 is a flow chart illustrating a computer subroutine used for switching from automatic control to manual control in accordance with the present invention. FIG. 4 is a flow chart illustrating a computer subroutine used for switching from manual control to automatic control in accordance with the present invention where the throttle valve is driven by a DC motor. FIG. 5 is a flow chart illustrating a computer subroutine used for switching from manual control to automatic control in accordance with the present invention where the throttle valve is controlled by a stepper motor. FIG. 6 illustrates an example of a logic sequencer used to drive the phase drivers for a stepper motor. FIG. 7 illustrates the waveforms for the step input and phase outputs for the logic sequencer shown in FIG. 6. FIG. 8 illustrates an example of another logic sequencer which may be used to drive the phase drivers for a stepper motor. FIG. 9 is a block diagram and partial schematic showing the logic sequencer of FIG. 6 or FIG. 8 and the phase drivers for a stepper motor. FIG. 10 is a schematic diagram of a partial control unit in accordance with the present invention and an analog converter for driving a DC motor. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The present invention comprises a number of interrelated elements, all of which are shown in at least some detail in FIG. 1. With reference to FIG. 1, the system in accordance with the present invention comprises control unit 1 powered by battery 6. Control unit 1 may comprise a micro-processor or may be formed with discrete components. Battery 6 may be specifically dedicated to control unit 1 or may be the main storage battery for the host vehicle. Accelerator pedal position signal α is provided to control unit 1 from accelerator pedal 2. Signal α may be generated from potentiometer 3 forming part of a voltage divider network. Signal φ is also provided to control unit 1 and indicates the position of throttle valve 4. Signal φ may be generated by potentiometer 5 also forming part of a voltage divider network. Signals α and φ are processed by control unit 1 to provide an output signal for controlling stepper motor 7. When control unit 1 comprises a micro-processor, the signal pulses for driving stepper motor 7 may be generated by the subroutine shown in FIG. 2, as discussed below. Stepper motor 7 is coupled to throttle valve 4 and sets throttle valve 4 to the position commanded by control unit 1. Alternatively, stepper motor 7 may be replaced by DC motor 8 which can be driven by control unit 1 through analog converter 9. During normal operation, control unit 1 controls the operation of throttle valve 4 by issuing commands to stepper motor 7 based upon signals α and φ. When control unit 1 comprises a microprocessor, various subroutines may be used to process these signals to provide the ideal throttle setting for optimum vehicle performance, e.g., maximum fuel efficiency and minimum exhaust emissions. When manual control is desired, throttle valve 4 may be operated by accelerator pedal 2 through clutch 11. Thus, when a malfunction is detected in control unit 1 or any place in the system, throttle valve 4 may be manually operated by accelerator pedal 2. In the manual mode, full operation of the vehicle is available to the driver. Thus, the vehicle is not limited to low speed operation, as are such systems known in the prior art. The control system in accordance with the present invention may also be used in conjunction with a continuously variable transmission. At high transmission ratios, it is desirable for the throttle valve to be directly controlled by the accelerator pedal when the vehicle is starting up. However, at low transmission ratios where the vehicle has reached operating speed, automatic control of the throttle is preferred. Thus, control unit 1 may be programmed to detect the transmission ratio in a continuously variable transmission and switch to the optimum control mode for the throttle. Where stepper motor 7 is used to operate throttle valve 4, as opposed to DC motor 8, and control unit 1 comprises a microprocessor, the micro-processor may be programmed to generate the appropriate pulses for controlling the stepper motor. With reference to FIG. 2, a flow chart is provided which illustrates the operation of a computer subroutine which may be used to generate the appropriate pulses. During step 20, N, j and i are initialized to zero. These valves are used as counters during execution of the subroutine. In step 21, the required number of pulses is calculated and assigned to variable N s in step 22. The subroutine then proceeds to step 23 where the pulse is turned on. The subroutine then enters the wait loop shown in step 24 for the duration of the on-pulse width. The pulse is then turned off in step 25 and a second wait loop is entered in step 26. The wait loop in step 26 establishes the off-pulse width. After the wait loop in step 26 is completed, the subroutine enters step 27 where counter N is advanced to indicate that another pulse has been completed. The subroutine then enters step 28 where counter N is compared to N s which indicates the total number of pulses required. If N is less than N s , the subroutine loops back to generate another pulse. If N is equal to or greater than N s , then the subroutine is completed. With reference to FIG. 3, the operation of switching from automatic control of throttle valve 4 to manual control by accelerator pedal 2 will be described. When it is desired to switch from automatic to manual control, clutch 11 is engaged as indicated in step 30 and the power to stepper motor 7 or DC motor 8 is removed as indicated in step 31. When the motor is deenergized, throttle valve 4 is urged toward a closed position by the action of spring 10 (see FIG. 1). Because the electrical power has been removed from the motor, its shaft, which is connected to throttle valve 4, freely turns as throttle valve 4 moves toward a closed position. Accelerator pedal position signal α is compared to throttle position signal φ in step 32. If signal α equals signal φ, the subroutine is completed and a return is executed indicating that the switch from automatic to manual control is complete. If signal α does not equal signal φ, the subroutine proceeds to step 33 where signal α is compared to zero. Zero indicates that the accelerator pedal is no longer depressed. If α does not equal zero, the subroutine loops back to step 32. However, if α equals zero, the subroutine proceeds to step 34 where clutch 11 is disengaged. The subroutine then enters the wait loop shown in step 35. The wait loop is provided to insure that throttle valve 4 returns to the closed position by the operation of spring 10 before clutch 11 is engaged in step 36, i.e., φ equals zero. The subroutine then executes a return indicating that the switch from automatic to manual control is complete. In the above-described subroutine, switching from the automatic mode to the manual mode is not completed until the state of the fuel delivery system as indicated by φ corresponds to an actual output power or torque which is substantially equal to the desired output power or torque commanded by accelerator pedal 2 as indicated by α. This is the logic decision performed in step 32 of the subroutine. Where φ=α, i.e., φ corresponds to an actual output power or torques which is equal to the desired output power of torque commanded by α, the switch from automatic to manual is complete and the return from the subroutine in step 37 is executed. Also when α=0 in step 33, i.e., accelerator pedal 2 is not depressed or desired output power is zero, and φ=0 at the end of step 35, i.e., actual output power is zero, the switch from automatic to manual is complete and the return from the subroutine in step 37 is executed. With reference to FIG. 4, the operation of switching from manual to automatic control when throttle valve 4 is driven by a DC motor will be described. As shown in step 40, electrical power is provided to the DC motor. The subroutine then proceeds to step 41 where clutch 11 is disengaged. The subroutine then executes the return shown in step 42 indicating that the switch from manual to automatic control is complete. FIG. 5 illustrates a flow chart for a computer subroutine when switching from manual to automatic control where throttle valve 4 is driven by a stepper motor. As shown in step 50, clutch 11 is first disengaged. The subroutine then enters the wait loop shown in step 51 before electrical power is provided to the stepper motor in step 52. FIG. 9 illustrates an interface which may be used between control unit 1 and stepper motor 7. The interface comprises logic sequencer 61 for receiving control signals from unit 1 and phase drivers 62-65 which drive the stepper motor. FIGS. 6 and 8 illustrate two embodiments of a logic sequencer which may comprise logic sequencer 61, and FIG. 7 illustrates the various signals associated with the logic sequencer. FIG. 10 is a schematic diagram illustrating a simplified control unit 1 using discrete components and analog converter 9 used to drive DC motor 8. Obviously, many modifications and variations of the abovedescribed preferred embodiments will become apparent to those skilled in the art from a reading of this disclosure. It should be realized that the invention is not limited to the particular system disclosed, but its scope is intended to be governed only by the scope of the appended claims.

What is disclosed is a system and method for effecting either automatic or manual control of a fuel delivery system for delivering a variable quantity of fuel to the engine of a power delivery system. Switching between automatic control and manual control does not occur until a smooth transition between control modes is assured. This is accomplished by ensuring that the pre-switching state of the fuel delivery means corresponds to an actual output power or torque which is substantially equal to the desired ouptut power or torque commanded by the manual control.

big_patent

This is a division of application Ser. No. 885,377, filed Mar. 10, 1978, now U.S. Pat. No. 4,177,740. BACKGROUND OF THE INVENTION 1. Field of the Invention This invention pertains to methods and apparatus for generating heat from particulate-laden gas or directly from waste fuels such as wood waste. 2. Description of the Prior Art Wood waste fuel burners, commonly known as hog fuel burners, have generally been extremely inefficient in combustion, discharging undesirable amounts of gaseous and particulate pollution. In addition, when these burners are coupled to a boiler the gases emitted to the boiler for heating are dirty causing depositions on the heat transfer tubes of the boiler which require frequent and expensive cleaning. Frequently, the particulate matter in the exhaust gases is also highly abrasive to the boiler heat transfer elements. As a result, conventional practice is to build an extremely large furnace chamber for a boiler allowing the discharge gases from the burner to reach a very low velocity so that particulate matter in the exhaust can drop out of the gas stream. Also, because of retained particulate matter, the gas passages in the tube banks of conventional boilers are generally made wider to minimize passage obstruction. Gas velocities of 50 to 60 ft./sec. are common in hog or wastewood fuel boilers while velocities of 110 to 120 ft./sec. are the rule in oil and gas fired packaged or field erected boilers. And lastly, once through the boiler, the economizer and the air preheater, the exhaust gases in conventional hog fuel boilers have to be cleaned in multiple cyclones (multicones) followed, typically, by electrostatic precipitators. What the industry has long needed is a clean burning waste fuel burner which can deliver exhaust gases as clean as those produced by oil and gas burners. The same burner could also replace oil and gas burners on lime kilns, plywood veneer dryers, particle board dryers, lumber dry kilns, etc. SUMMARY OF THE INVENTION It is an object of this invention to provide a waste fuel burner which emits discharges of very minimal quantities of particulate materials within the levels permitted by local environmental regulations. It is another object of this invention to provide a waste wood fuel burner which operates producing little slag or clinkers. It is another object of this invention to provide a waste wood fuel burner which can effectively burn wet wood of 70% moisture content (wet basis). It is still another object of this invention to provide a waste fuel burner that is self-regulating, easy to control and has fast response times to changes in the load comparable to conventional gas and oil burners. It is another object to provide a waste fuel burner that burns wood of nominal ash content (e.g. 5% ash) and produces a residue that is free of clinkers (assuming the ash fusing temperature is not lower than 1700° F.) Basically, these objects are met by method and apparatus which forms a conical pile of waste fuel, fed from below, with preheated underfire air percolating up through the pile in controlled amounts, drying and gasifying the waste fuel in the pile. The volatile gases driven off the pile by heat generated by the oxidation of the fixed carbon on the surface of the pile are then partially oxidized by additional combustion air introduced tangentially with a very vigorous swirl in a first or primary combustion chamber with the total amount of combustion air admitted to the primary chamber being maintained at less than stoichiometric proportions so that the temperature in the primary combustion chamber remains lower than the necessary to melt the natural ash, dirt or other inorganic substances in the fuel. The additional or swirl air is introduced in an amount necessary to maintain a steady temperature at the exit of the primary chamber and is dependent upon the moisture content and type of fuel. The swirl air also forces particulate out of the gas stream leaving the primary chamber. The volatile gases are discharged from the throat of the primary combustion chamber around an air cooled disc or flame holder which forces the gases, and any entrained particulate matter, out to the walls of the throat, thereby causing such entrained matter, if any, to centrifugally separate and fall back into the primary chamber. That is, the flame holder serves as a barrier against the particulate but allows passage of gases therearound. The volatile gases move around the disc shaped flame holder into a second combustion chamber where secondary combustion air is introduced to an amount above stoichiometric proportions for complete combustion. The secondary air introduced in the secondary combustion chamber is directed tangentially. Preferably, the combustion air introduced to the primary and secondary chambers is introduced on the outside of a refractory lining to cool the lining and increase its life. Preferably, also, the secondary combustion air introduced in the secondary combustion chamber can be introduced at various axial locations in that chamber to regulate the position of the flame within the chamber. Finally, if desired, additional blend air can be added to the discharge of the secondary chamber to cool the air for industrial purposes other than boiler heat. The swirl air and secondary combustion air combine or interact dependent upon moisture content of the fuel to maintain good separation of the particulate from the gas stream leaving the primary chamber thus keeping the particulate out of the secondary chamber where high temperatures could cause slag formation. For example, as moisture content rises the temperature in the primary chamber will drop causing a demand for more swirl air to raise the combustion temperature in the primary chamber. This swirl air will vigorously separate the particulate by centrifugal separation. If moisture content drops, the temperature in the primary chamber will increase thus reducing the need for swirl air to maintain the steady exit temperature. As swirl air is reduced however the secondary air begins to shift downwardly because of the reduced pressure in the primary chamber thus diverting particulate trying to leave the primary chamber back into the primary chamber. That is, the secondary combustion air travels down in a spiral along the wall of the secondary chamber, then moves across the exit of the primary chamber and joins with the upwardly rising inner vortex of combustion gases above the flame holder. Particulate is swept back down into the primary chamber by this action. In a second embodiment a cylindrical restriction or pressure isolator fitted with a multiplicity of radial vanes is coupled to the air cooled flame holder. The restriction serves to isolate the primary chamber from the secondary chamber air by imposing an additional resistance to tangential secondary combustion air movement into the two primary chamber but, at the same time permits the free fall of any separated particulate matter back into the primary chamber. A unique aspect of the invention is that while advantageously used for a wood waste burner the primary and secondary chambers can be added to any source of dirty particulate-laden combustible gas and effectively burn the gas to provide a source of useful heat and remove the particulate for meeting environmental emission standards. As an example the primary chamber can be coupled directly to the exhaust of a coking operation for burning the gases and removing particulate from the exhaust. BRIEF DESCRIPTION OF THE FIGURES OF THE DRAWING FIG. 1 is an axial partial section of a waste fuel burner embodying the principles of the invention. FIG. 2 is a fragmentary section taken along the line 2--2 of FIG. 1. FIG. 3 is a fragmentary detail section of a second embodiment incorporating a pressure isolator. FIG. 4 is a schematic pneumatic control diagram. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The burner includes a primary combustion chamber 10 having an internal side wall 11, a discharge opening 12 and a bottom 13. The chamber is lined with refractory material 14 which is spaced from an outer metallic shell 15 by an air cooling passage 16. Fuel (where the combustible material is a solid wood waste rather than merely particulate-laden gas) is fed from a hopper by a conveyor 18 of conventional construction either of the screw or ram type and is pushed into the form of a conical pile F. Preheated underfire combustion air is carried by a conduit 20 and directed into two chambers 20a and 20b. The chambers are in effect concentric rings each being fed a regulated desired amount of air to percolate or blow up through the pile. This air is preheated to about 500° F. The ring 20a being located beneath the outer less thick level of the conical pile is held to a lower air pressure so that blow holes will not be formed in the pile. Blow holes disturb the gasification and result in underfire air completing the combustion of the volatiles generated in the region of the blow hole, leading to high temperatures in the same region with attendant ash fushion and clinker generation. High pressure swirl air is admitted through tuyeres 22. The tuyeres are at an angle to the side wall 11 so that the air is admitted tangentially and the resulting swirl generates centrifugal forces which drive the heavier non-combusted materials to the outer wall 11 while allowing the volatile gases to pass upward through the throat of the primary chamber. The tuyeres 22 are located high up in the chamber side wall so that the air introduced will not disturb the surface of the pile of fuel. The tuyeres have a wedge-shaped portion 23 with a plug wedge 24 that is externally adjustable by a handle 26. Thus each of the tuyeres which are circumferentially spaced around the primary combustion chamber are individually adjustable to regulate the exact amount of air and the velocity of this air introduced into the primary combustion chamber. The secondary chamber also is provided with a side wall 33, a roof 34, an outlet 36 and a refractory lining 38 on the side walls and roof. The refractory lining is separated from the outer shell by an air passage 39 for cooling the refractory lining. Additional or secondary combustion air is introduced at tuyeres 40a, 40b, and 40c which are circumferentially and axially spaced within the secondary combustion chamber. These tuyeres are all adjustable in the same manner as the tuyeres of the primary combustion chamber. The axial positioning of the tuyeres is effective for adjusting the location where the air is introduced into the secondary chamber and assists in positioning the flame for various types of fuels and moisture contents of fuels. As best shown in FIG. 1, the volatile gas passing through discharge 12 from the primary chamber works its way past an air cooled horizontal, disc shaped flame holder, 44, upon entering the secondary chamber. The flame holder is positioned in the center of the secondary chamber, below the bottom row of tuyeres 40c and causes the primary chamber gases to flow radially outward and around the flame holder forming again directly above the flame holder in an inner vortex. The flame holder could be ceramic but in the preferred embodiment is air cooled by admitting secondary air via hollow support pipes 43, the flow of cooling air being established by bleeding such air from the outer surface of the flame holder via a plurality of small diameter bleed holes 45. Secondary combustion air is admitted tangentially to the secondary chamber via three rows of adjustable tuyeres 40a, 40b, and 40c. Because of the roof 34 and choke 36, the secondary combustion air spirals down the walls of the secondary chamber to meet the mixture of volatile gases and moisture spiraling up around the flame holder from the primary chamber. The two flows merge and, still swirling, flow radially inward above the flame holder where final combustion takes place. Combustion is completed in this inner vortex of upward spiralling flame centered above the flame holder and along the axis of the secondary chamber. The inner vortex is surrounded, and the refrectory is protected, by the outer vortex of downward spiraling combustion air. The final products of combustion leave the secondary chamber through the choke 36 still spiraling, at temperatures which, depending upon the moisture content of the waste fuel and the quantity of excess air, can reach 3000° F. The flame holder also serves as a barrier and prevents the secondary chamber inner vortex from drawing primary chamber particulate material up into the secondary chamber. Should some primary chamber particulate find its way out of the primary chamber into the primary chamber throat and then past the flame holder into the secondary chamber, the flame holder forces it out towards the walls where it is acted upon by the various outer vortex of the secondary chamber. Because of the smooth and continuous transition of the secondary chamber walls with those of the throat of the primary chamber, such elusive particles then fall back down into the primary chamber where the combustible portion will later be removed. In the embodiment of FIG. 3 a pressure isolator 33 is shown in the throat of the primary chamber below the flame holder 44. The isolator shown is a thin walled circular cylinder supported by a plurality of radial vanes 64 of the same axial length as the circular cylinder which extend from the outer surface of said cylinder to the throat walls. The entire pressure isolator can be air cooled in a similar manner to the flame holder. The purpose of the pressure isolator is to isolate the primary chamber from secondary chamber combustion air. Because of the radial vanes the resistance presented to the downward spiraling secondary combustion air is high (the radial vanes destroy the angular momentum) the tendency for this air to enter the primary chamber is minimized. The primary chamber volatiles, however, readily find their way up through the center of the pressure isolator and into the secondary chamber. Any particulate matter brought with these gases into the secondary chamber is thrown outwards as before and because of the open passages between the refractory walls and the outer surface of the central cylinder, falls back down into the primary chamber. The quantity of high pressure swirl air admitted to the primary chamber is varied according to the primary chamber exit temperature measured by thermocouple 70. Should this temperature fall too low and jeopardize either the rate of gasification in the primary chamber or continuous ignition in the secondary chamber, then the amount of primary swirl air is increased by the burner controls. Similarly, if the primary chamber exit temperature rises above an acceptable limit, and possibly melt, or, at least, cause to coalesce some of the noncombustible matter in the fuel, then the amount of primary swirl air is decreased by the burner controls. In the latter case the reduction of swirl air will reduce the centrifugal separation forces on primary chamber particulate matter. However, this reduction will be offset by an increase in the centrifugal separation forces in the secondary chamber as follows: the increase in volatile matter reaching the secondary chamber will produce higher temperatures in this chamber as measured by thermocouple 72. The secondary chamber controls will then call for more secondary air to lower the secondary chamber exit temperature. This additional secondary air results in higher tengential velocities at the walls of the secondary chamber leading to an increase in centrifugal separation forces in this chamber. Conventional gas burners 28 are mounted in the sides of the primary and secondary chamber. The primary chamber gas burner serves to ignite the fuel pile on start-up while the secondary chamber burner serves to preheat the secondary chamber and complete the combustion of the initial low temperature gases coming from the primary chamber during start-up. To summarize the principle of operation, most conventional hog fuel or waste fuel burners are run with an air supply considerably greater than that necessary for stoichiometric combustion. Stoichiometric combustion, as is well known, is the precise amount of air necessary to obtain complete combustion of the organic materials in the waste fuel. This quantity of air will vary depending on moisture content and the nature of the fuel. Conventional hog fuel burners burn intentionally with about 80% more combustion air than is needed for stoichiometric combustion. The reason for this is that because the moisture content, and nature of the fuel is continuously varying the prior art burners overcompensate to assure that they get above stoichiometric so that combustion is complete and no undesirable smoke is formed. Generally, however, in operation these prior art burners reach excess air levels of up to 200%. This is extremely wasteful since the air must be delivered by blowers and reduces the final exhaust temperature because of the dilution of the heated gas with excess cool air. The invention described in this application burns considerably below stoichiometric proportions in the primary combustion chamber where slag-forming non-combustible material is found and only about 20% excess of stoichiometric in the secondary chamber. Furthermore, since all of the drying of the fuel occurs in the primary combustion chamber the gases reaching the secondary combustion chamber are uniform in nature allowing fuels up to 70% moisture content to be burned with good performance. By running at such a low excess air the temperatures in the primary chamber can be easily maintained below 1600° F. Other advantages of this invention are that it can be adjusted to operate with a low volume of fuel or a high volume of fuel being variable from approximately x million Btu/hr to x/5 million Btu/hr where x is the burner rating; since not only can the feed of fuel be controlled quickly, but the underfire air coming in through conduit 20 can also be shut down quickly giving a response time in changing the output Btu/hr of the heater of less than 1 minute. This is to be compared to conventional prior art pile burners which require as must as 30 minutes to change their Btu output. The advantage of the quick response time is that the demands of the boiler can be more quickly met. Still another advantage is that since very little clinker or slag formation is formed in the primary and secondary chambers only very infrequent cleaning is needed and the cleaning is primarily limited to dry ash removal. Since the combustion air is passed over the refractory lining the lining has a much longer life because it seldom exceeds temperatures of about 1200° F. Even when the highest temperature region of the flame in the secondary chamber is as high as 3000° F. Still further, with applicant's invention, the size and quality of the pieces of fuel fed to the pile is not critical whereas in the prior art, many systems require that the fuel be first pulverized or made of uniform size before it can be efficiently burned. The discharge gases from the secondary chamber 32 can go direct to the boiler and because of their cleanliness the boiler can be small and obtain high heat transfer by maintaining the high velocity of the gases. If used for other industrial purposes requiring a lower temperature the gases can be mixed with additional outside air in a blend chamber 50 with its discharge going to a kiln dryer or other industrial use. Part of the hot gases are tapped off via conduit 54 and used to preheat underfire air in a heat exchanger 65. The description of the control schematic shown in FIG. 4 wil further illustrate the principle of operation. BTU demand of the heat consuming process or equipment such as a boiler establishes burner output. In an actual installation steam pressure (boiler), dry bulb temperature (dry kiln) or tail end temperature (rotary dryer) alter the burner's BTU demand set point. BTU demand controls the air and wood feed rate. There are three fans supplying underfire, swirl and secondary air. Each fan's output is affected by the demand signal. Fan output is controlled by an outlet damper at each fan. The BTU demand signal is fed in parallel to: (1) an hydraulic pump 69 which powers an hydraulic motor 80, the motor 80 drives a wood supply conveyor which delivers wood waste to a conventional reciprocating ram stoker 81; (2) the underfire fan damper actuator 84; (3) the swirl air fan damper actuator 85; and (4) the secondary air fan damper actuator 86. As demand increases, each of the fan outputs and the wood flow increase. Conversely, as demand decreases the wood and air supplied decrease. The speed of the hydraulic motor (i.e. wood flow) is maintained constant for that demand setting by comparing the output of a tachometer 90 with the demand setting and automatically adjusting the hydraulic pump actuator accordingly (via a conventional controller 81). Overrides or trims are provided on the swirl air and secondary air quantities. The swirl air is trimmed by the temperature at the outlet from the primary chamber. This temperature is measured by a probe 70 at the outlet of the primary chamber 10. The secondary air is trimmed by either the temperature at the outlet from the secondary chamber or the oxygen level at that point. This temperature, for example, is measured by a probe 72 above the outlet of the secondary chamber 32. The swirl air trim drops the primary chamber outlet temperature by providing less combustion air and thus burning less of the volatiles in this chamber. That is, as the temperature gets higher than a preset set point the quantity of swirl air is reduced to lower the primary chamber exit temperature. Since the reduced swirl air will reduce particulate separation due to less cyclonic action, particulate separation from the volatile gases is maintained by the cyclonic action of the secondary air immediately above the primary chamber outlet. Advantageously as swirl air is reduced because of high temperatures in the primary chamber (a condition of low moisture content in the wood) the quantity of secondary air is increased to prevent excessive temperatures in the secondary chamber. The additional secondary air will increase cyclonic action in the secondary chamber thus driving the particulate outwardly and downwardly back into the primary chamber. Finally the secondary air trim increases the secondary air to maintain outlet temperatures from the secondary chamber compatible with long refractory life. When oxygen is used to trim the secondary air (for example, on a boiler) then the secondary air is normally reduced to maintain a fixed excess air (15 to 20% nominally). The underfire air is the gasifying air, that is, the air which provides the volatiles to be burnt above the pile and especially, in the secondary chamber. In fact, while all other air controls operate only on the cruder accuracy outlet damper position, the underfire air control operates on the pressure drop across an inlet orifice 104 to determine actual air flow. BTU demand calls for a certain underfire air flow which is then established by the outlet damper actuator 84. The fresh underfire air is pre-heated in a heat exchanger 90. The underfire air supply temperature is controlled from a thermocouple 91 which controls an exhaust damper 92 from the hot gas side of the heat exchanger. Manual or automatic selection controls 98 are provided in each control circuit to allow manual override of each trim control. The embodiment of the control system disclosed is pneumatic. However, electrical controls are also satisfactory. While the preferred embodiments of the invention have been illustrated and described it should be understood that variations will be apparent to one skilled in the art without departing from the principles herein.

A combustion method in which heat is generated from particulate laden combustible gas containing mineral matter created from gasifying waste wood, coke or other combustible material in which the waste is fed into a pile, under-fire combustion air dries and gasifies the waste, oxidizing the fixed carbon in a first chamber to generate heat at a temperature less than the melting temperature of the non-combustible material so as not to form slag, adding air in the first chamber in an amount less than stoichiometric with the air introduced in a swirling fashion to move the particulate laterally away from the discharge of the primary chamber, impeding the movement of this particulate also by adding secondary combustion air in a downward swirling direction in the secondary chamber so that very little non-combustible material reaches the second chamber where melting can occur.

big_patent

This is a division of application Ser. No. 601,873, filed Aug. 4, 1975, now U.S. Pat. No. 4,023,949. FIELD OF THE INVENTION The field of art to which the invention pertains includes the field of air conditioning, more specifically the field of evaporative refrigeration. BACKGROUND AND SUMMARY OF THE INVENTION Evaporative air conditioners have found use in localities where there is a sufficient difference between the dry bulb temperature and the corresponding wet bulb temperature to provide a desirable heat transfer gradient without need for altering the moisture content of the useful air or for resorting to vapor compression refrigeration. For example, if the dry bulb temperature is 93° F and the corresponding wet bulb temperature is 70° F, there is a difference of 23° F available for air conditioning operation. Early coolers operated by evaporating water directly into the useful air, thereby increasing its moisture level, but subsequent coolers have been based on the fact that the occupants of an enclosure will experience a greater degree of comfort by cooling the air of the enclosure while maintaining, or reducing, its moisture content. A variety of sophisticated designs have been proposed and utilized wherein the heat absorptive action of evaporation is employed to reduce the temperature of heat exchange apparatus and in which air is then passed through the apparatus for the purpose of cooling. The air that is used for effecting the evaporation (working air) is conducted to the outside of the room to be cooled and the air that is cooled by passing through the apparatus (useful air) is directed into the room. In this way, the heat abstracted from the liquid during the evaporation is not redelivered to the air of the room, nor is the moisture content of the useful air increased. In this regard, one can refer to the following U.S. Pat. Nos. Re. 17,998, 2,044,352, 2,150,514, 2,157,531, 2,174,060, 2,196,644, 2,209,939, 2,784,571 and 3,214,936. Additional patents of interest are: U.S. Pat. Nos. 1,542,081, 2,488,116 and 3,025,685. In more recent years, evaporative coolers have been replaced by vapor compression refrigeration units in which refrigerant fluid is alternately compressed and evaporated in a refrigeration cycle. Such units can be made quite compact, but are generally inefficient and, importantly, energy-intensive. Dwindling energy resources have required priorities in this regard to be reexamined and the need for improved, more efficient cooling devices has become evident. The present invention satisfies the foregoing need in that it provides a highly efficient apparatus for cooling of air. The device operates more efficiently by a conjunction of features. Specifically, a heat exchanger is used that separates its dry and wet sides; evaporating water is kept separate from the useful air so that cooling is performed without the addition of water vapor to the useful air. Additionally, the major portion, preferably all, of the working air, is drawn from the load; i.e., the working air is recirculated from the enclosure to be cooled to the wet side of the heat exchanger. Furthermore, in a preferable mode of construction, the wet side of the heat exchanger operates by movement of the working air internally through conduits countercurrently to water flowing downwardly therethrough along the conduit inner surfaces, while the useful air passes through the dry side externally across the conduits. Specific constructional details for maximum efficiency are given hereinafter. In a specific embodiment, additional increases in efficiency can be obtained by flowing the moisture-laden return air exhausting from the wet side of the heat exchanger in heat-exchange, but separated, relationship with fresh air flow upstream from the dry side of the heat exchanger. In a further embodiment, a composite, hybrid system is provided in which a minor portion only of the useful air, downstream of the dry side of the heat exchanger, is passed over the evaporator of a vapor compression refrigeration system. A sufficiently small amount of the useful air can thus be cooled sufficiently below its dew point to dehumidify that portion of the air resulting in a greater reduction in the dry bulb temperature of the useful air. Other features are provided which, while decreasing somewhat from the total efficiency of the basic system, provide a greater degree or rate of cooling than heretofore possible with evaporative coolers for specialized applications and/or for high cooling rate usage. In this regard, a particular embodiment calls for a portion of the returned air to be diverted to mix with the fresh air for further cooling by the heat exchanger. In another particular embodiment, useful under certain climatic conditions to provide a lower temperature but at higher energy levels, a portion of the cooled useful air emerging from the heat exchanger is diverted to mix with the working return air for countercurrent contact with the evaporating water. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic "circuit" diagram of an evaporative cooler system embodying basic concepts of the present invention; FIG. 2 is a diagrammatic elevational view of a specific embodiment of the system of FIG. 1; FIG. 3 is a plan view of a portion of the heat exchanger tube array and header, taken on line 3--3 of FIG. 2; FIG. 4 is an enlarged view of a portion of FIG. 3 below the header; and FIG. 5 is a diagrammatic elevational view of a hybrid evaporative cooler system which incorporates the components of a vapor compression refrigeration unit. DETAILED DESCRIPTION As required, detailed illustrative embodiments of the invention are disclosed herein. The embodiments exemplify the invention and are currently considered to be the best embodiments for such purposes. However, it is to be recognized that the units may be constructed in various other forms different from that disclosed. Accordingly, the specific structural details disclosed are representative and provide a basis for the claims which define the scope of the present invention. As above-indicated, the present evaporative refrigeration system is one in which the evaporating water is kept separate from the cooling air stream by means of a heat exchanger so that cooling is performed without the addition of water vapor, achieving sensible cooling. To effect the maximum cooling available at the lowest energy cost, at least a major portion, preferably all, of the working air used for the wet side of the apparatus is drawn from the room to be cooled (load), because it has a lower wet bulb temperature than outside, fresh air and thus a larger temperature differential can be obtained than if fresh air were used for that purpose. It is also preferred that the major portion of useful air, i.e., air passing through the dry side of the heat exchanger, be fresh air. A particularly useful form of apparatus to accomplish the foregoing is one utilizing an array of spaced vertically directed hollow elongated tubular members. The wet side is accomplished by gravity flow of water downwardly along the inner surfaces of the tubes in conjunction with countercurrent flow of returned air from the load, to exhaust. The dry side is accomplished by fresh air flowing in thermal conductive contact with the outer surfaces of the tubular members for cooling thereof, the cooled fresh air being delivered to the enclosure. Referring to FIG. 1, there are illustrated various air flow paths which can be utilized by the present embodiment. The system includes a heat exchanger 10 through which fresh air 12 passes on the dry side emerging as two streams 14 and 16 of cooled useful air for flowing to two different zone locations 18 and 20, respectively, of an enclosure 22 to be cooled. A stream of return air 24 is flowed back to the heat exchanger 10 and constitutes a working fluid for evaporation of water within the heat exchanger 10, as will be described in more detail hereinafter. The moisture-laden return air exits as an exhaust stream 26, which, in a particular embodiment, is flowed in heat exchange relationship, as indicated at 28, with the fresh air 12 before being disposed exteriorly of the device and of the enclosure. In accordance with a particular variation of operation, a portion of the return air can be diverted as a recirculation stream 30 to mix with the fresh air 12. By such means, the enclosure can be cooled more quickly than otherwise, although at a higher energy cost. In accordance with other variations of operation, portions of the cooled air streams 14 and 16 can be diverted as a by-pass streams 32 and 34, respectively, to mix with the working return air stream 24, passing through the wet side of the heat exchanger 10. Such a configuration is useful under certain climatic conditions to enable a lower temperature, but again at a higher energy cost. Referring now to FIG. 2, the heat exchanger 10 comprises an array of spaced vertically directed hollow elongated tubular members 36 stacked between top and bottom header 38 and 40, respectively, so as to form a dry side enclosure 42 bounded on top and bottom by the headers 38 and 40, on the downstream side by a side wall 44 and on the upstream side by a filter 46. The side wall 44 is spaced sufficiently from the array of tubular members 36 so as to accommodate therein a pair of blowers 48 and 50. The blowers 48 and 50 are shown stacked one above the other, but may be disposed laterally adjacent each other. They draw fresh air 12 via ductwork 52 through the filter 46, past the external surfaces of the tubular members 36 in the dry side 42 of the heat exchanger, where the fresh air is cooled, and then distributes the cooled air to ductwork 54 and 56, opening into the enclosure 22, as the separate cooled air streams 14 and 16 referred to above. It is preferred to draw, rather than push, the useful air through the heat exchanger as such provides the most uniform air distribution without recourse to baffles, static plates or other such devices which would introduce additional resistance to airflow in the system. By using a pair of blowers 48 and 50, the cooled air can be passed to spaced zones 18 and 20 in the enclosure 22. The blowers 48 and 50 are variable speed blowers which are independently controlled by their own thermostats 58 and 60 located as desired respective the enclosure zones 18 and 20 to be cooled. Ductwork 62 communicates with the enclosure 22 at 64 and conveys return air 24 to a blower compartment 66 in which a return air blower 68 pushes the return air into a plenum 70. The plenum 70 is disposed below and in communication with the interior surfaces of the tubular members 36 and is separated from the dry side of the heat exchanger by means of the bottom header 40. The plenum 70 also serves as a sump for containing a reservoir of water 72 for evaporation. The water 72 is fed by means of a water pump 74 and a suitable pipeline 76 to an array of manifold tubes 78 overlying the top header 38. The water 72 emerges from jets 80 in the manifold tube array 78 onto the top header 38 flowing into and downwardly along the inner surfaces of the tubular members 36, by the force of gravity, returning to the plenum 70 and reservoir of water 72 therein. The blower 68 pushes the working return air 24 upwardly through the tubular member 36 countercurrently to flow of the water 72, resulting in evaporation of a portion of the water 72, thereby abstracting heat from the walls of the tubular members 36. The moisture-laden air is discharged as an exhaust stream 36 from the top of the heat exchanger where it is conducted by ductwork 82 to a point of discharge 84. The ductwork 82 is formed with an annular section surrounding the fresh air ductwork 52 to provide a heat exchange assembly 28 to pre-cool the fresh air 12. Although the return air 24 is shown as being pushed through the wet side of the heat exchanger by the blower 68, an alternative, somewhat more efficient, arrangement is to mount the blower at the top of the heat exchanger to draw the moist air through the wet side and into the ductwork 82. Referring more specifically to the plenum 70, water which is not consumed in the evaporation process flows from the inner surfaces of the tubular members 36 and drips into the reservoir of water 72. The pump 74 can be a submersible pump as shown located within the reservoir of water 72, or can be external to the reservoir. Water is introduced into the plenum-sump region by means of a ball-float valve 86 connected to an input pipe 88. Scale and/or lime formations are minimized by use of a bleed-down system defined by a syphon 90. The syphon is located in the plenum, spaced just above the operational level of the reservoir 72 as determined by the ball-float valve 86 but below the level reached when operation of the unit is terminated. At that time, the reservoir water level will rise due to natural drain-back and the syphon 90 will cause a partial draining or bleed-down to expel contaminated water. Other methods of reducing contamination build-up, e.g., by means of a bleed line in the discharge line from the pump, can be used. Other methods of water distribution than the manifold 78 can be used. For example, a trough network can be disposed over the top header 38 whereby water flows by gravity through notches in the sides of the troughs. Alternatively, a water trough system can be constructed integral with the top header 38 whereby the troughs would be disposed between the tubes and the water would flow from the troughs into and down through the tubes directly. As earlier indicated, provision is made for recirculation of return air and for bypass of cooled air. With respect to the first provision, ductwork 92 leads from the return ductwork 62 to a region 94 adjacent the bottom of the fresh air filter 46. By such means, a portion of the return air 24 can be diverted, as shown at 98, to mix with the fresh air 12, thereby increasing the cooling rate. The amount of return air thus recirculated can be effected by means of a damper 100 disposed in the recirculation ductwork 92. With respect to the second provision, ductwork 102 and 104 can be connected to the supply ductwork 54 and 56 to permit flow of bypass cooled air 32 and 34 therethrough to the return air blower compartment 66, regulated by dampers 106 and 108 (the lower portion of the ductwork 104 being hidden by the ductwork 102 in the view of FIG. 2). By such means a lower useful air temperature is achieved. Details of construction of the array of tubular members 36 can be seen in FIGS. 3 and 4. The tubular members 36 are substantially square in external cross-sectional configuration, but are formed with substantially rounded corners. By using squared tubes, an array matrix can be obtained that permits greater external surface area than other configurations. The extent of spacing between the tubes is chosen so as to obtain a desired flow rate of fresh air on the dry side. Referring in particular to FIG. 4, in the specific configuration illustrated, the distance 110 between diagonally adjacent tubes is about twice the distance 112 between laterally adjacent tubes. In general, the distances chosen with respect to any particular size tubes should be such as to permit the desired flow rate in the free area between the tubes. Preferably, the external side dimension of each tube is greater than three times the external distance between laterally adjacent tubes and a ratio of about 5.6 is illustrated in FIG. 4. Referring again particularly to FIG. 3, a portion only of the header 38 is illustrated and the specific tubular array illustrated is comprised of 449 tubes arranged in 12 rows of twenty tubes each alternating with eleven rows of 19 tubes each. The particular tubes illustrated have a wall thickness of 0.03-0.04 inch. With the specific array illustrated, and an external side dimension of 1.25 inch, lateral distance between tubes of 0.225 inch and diagonal distance between tubes of 0.45 inch, the air "sees" a dry side free area of 1.79 ft 2 . Again referring particularly to FIG. 4, the inner surfaces of the tubes are formed with longitudinal grooves 114 which parallel the flow of water and wet side air. The grooves serve to draw and spread the water by capillary action to wet the inner tube surfaces, providing a uniform film to enhance evaporation. An example of the operating efficiency of the specific apparatus of FIGS. 2-4, can be calculated for a particular enclosure. With the dampers 100, 106 and 108 closed, with a heat exchanger efficiency of 80%, with fresh air at 93° F dry bulb and 70° F wet bulb, after equilibrium conditions have been obtained, at 1680 feet per minute operation, the air supplied to the enclosure will be 71.6 ° F dry bulb. If the enclosure heat load is 30,000 BTU/hr. the air leaving the enclosure will be 80.8° F dry bulb and 66.2° F wet bulb, with an average room or enclosure condition of 76° F dry bulb at 58% relative humidity. If in place of return air from the load, one would use fresh air as the working air for the wet side of the heat exchanger (70° F wet bulb temperature) the resultant cooled enclosure would have an average dry bulb temperature of 74.6° F instead of 71.6° F. Accordingly, there is demonstrated the importance of using the return air as the working fluid on the wet side of the heat exchanger, as provided for by the present construction. Furthermore, while it is not possible to achieve 100% efficiency, an efficiency of as much as 90% can be achieved by an increase in the number of heat exchange tubes. Under such conditions, with the present type of construction, a useful air stream can be obtained having a dry bulb temperature of 67.8° F. The foregoing apparatus has a capacity of 30,000 BTU per hour and is comparable to a vapor compression refrigeration unit of about 37.500-42,800 BTU per hour total capacity (3-3.5 tons). Vapor compression refrigeration units have inherent limitations in the sensible capacity of their cooling coils (between 70 and 80%) whereas an evaporative cooler of the present construction is totally sensible. Furthermore, a comparative vapor compression refrigeration unit would require power consumption of from 4 to 8 killowatts whereas the above illustrated evaporative cooler has a power consumption of about 1 to 1.5 kilowatts. Referring now to FIG. 5, as a further embodiment of the invention, a composite hybrid system is illustrated in which a portion of the cooled air stream is further cooled by heat exchange with the evaporator of a vapor compression refrigeration unit. Otherwise, the system is substantially the same as that illustrated in FIG. 2 except for the ommission of the heat exchange ductwork, the lateral disposition of the dry side blowers (one of which 48' only is shown) and resultant modification of configuration of the associated ductwork 102' and 104'. In this hybrid embodiment, the vapor compression refrigeration unit is defined by a compressor 116 connected by appropriate refrigerant line tubing 118 to a condenser coil 120 which in turn is connected by refrigerant line tubing 122 to an evaporator coil 124 connected via refrigerant line tubing 126 back to the compressor 116. The evaporator coil 124 is disposed in the dry side compartment of the heat exchanger downstream of the tubular members 36' so as to operate in the lowest possible air temperature region within the apparatus. Only a minor portion, preferably less than 25%, of the cooled air leaving the heat exchanger is contacted by the evaporator coil 124 so that a sufficient drop in temperature is accomplished in that portion of the cooled air stream to fall below the dew point. If the entire air stream were to pass by the evaporator coil, the drop in temperature would be insufficient to reach the dew point, but with only small amount of the air being so processed, the dew point is passed and the air is dehumidified. For example, in processing 14% of the cooled air past the evaporator coil 124, a dry bulb reduction of 3.8° F can be obtained compared to operation without dehumidification. The moisture removed from the air, which in the example, is at approximately 53° F, is collected at the base of the evaporator coil 241 and drained to the plenum region 70', by means of an evaporate collection tube 128. The evaporate water will be of lower temperature than the wet bulb temperature of the wet side air and will therefore further enhance the performance of the unit. Since the pressure at the wet side is higher than that of the dry side, a "p-trap" 130 is formed at the end of the evaporate collection tube 128, to prevent blow-back of the condensed moisture into the dry side. By removing some of the moisture from the useful air, the wet bulb temperature is further reduced, so that after circulating through the enclosure or load, it is recirculated back to pass through the wet side of the heat exchanger as working air with a lower web bulb temperature, thereby cooling the heat exchanger tubes toward that lower temperature by evaporating the water on the wet side. This increases the effectiveness of the heat exchanger resulting in a further depression of the dry bulb temperature of the incoming useful air on the dry side. In the example presented herein, this additional cooling effect reduces the average enclosure temperature an additional 1° F. As a further aid to operation and economy, the condenser coil 120 is disposed in the discharge path of the wet side of the heat exchanger. Accordingly, the condensing process takes place in an air stream of 65° F as opposed to the outside air temperature of 93° F. The combination results in significant reductions in energy required to operate the vapor compression refrigeration unit, resulting in a power requirement of only 50% of normal.

Air is evaporatively cooled by water in which the evaporating water is kept separate from the useful air (cooled air stream) by means of a heat exchanger so that cooling is performed without the addition of water vapor to the useful air, and in which the working air, absorbing the water vapor, is drawn from the load. A heat exchanger is disclosed which operates by movement of the working air internally through tubular conduits countercurrently to water flowing downwardly on the inner surfaces thereof while the air to be cooled passes externally across the conduits.

big_patent

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims the benefit of U.S. patent application 62/055,020, filed Sep. 25, 2014, the contents of which are incorporated herein by reference. FIELD [0002] This application relates to pumps, in particular to pumps for pumping fluids. BACKGROUND [0003] Liquid manure from animal husbandry operations, particularly pig farming operations, is typically stored in a large manure reservoir or lagoon until there is a sufficient quantity available to spread or irrigate onto farm land for disposal. In order to remove the manure from the reservoir, a pump is used that is typically located alongside the reservoir and lowered into the reservoir. The pump can be free standing or attached to a tractor, which is often preferable to provide stability to the pump and a source of motive power for the pump. [0004] A pump for pumping fluids at high volumetric flow rate (e.g. in excess of 4000 gal/min), particularly for pumping liquid manure from a reservoir, has been previously described in U.S. Patent Publication 2012/0224982 published Sep. 6, 2012, the contents of which is herein incorporated by reference. Such a pump has large fluid openings and generous tolerances in order that solid material in the reservoir can be accommodated by the pump without plugging. While excellent for pumping high volumes of fluid, such a pump generally operates at low pressure. For some applications, it may be desirable to not only pump fluid at high volumetric flow rate, but to also pump the fluid under high pressure. [0005] Accordingly, there still exists a need for improved pumps, particularly pumps capable of pumping fluids at high volumetric flow rate and high pressure. SUMMARY [0006] In one aspect, there is provided a fluid pump comprising: a first pump head comprising a first housing containing a first impeller configured to move fluid through at least three first conduits in fluid communication with the first housing; a second pump head comprising a second housing containing a second impeller configure to move fluid through at least three second conduits in fluid communication with the second housing, the at least three second conduits in fluid communication with an inlet into the first housing along a fluid flow path between the first and second pump heads, the at least three second conduits combining fluid flow therethrough at the inlet to provide a single flow of fluid through the inlet into the first housing; and, a drive structure passing through the inlet between the first and second pump heads, the drive structure configured to commonly drive the first and second impellers. [0007] In another aspect, there is provided a fluid pump comprising: a first pump head comprising a first housing containing a first impeller configured to move fluid through at least three first conduits in fluid communication with the first housing; a second pump head comprising a second housing containing a second impeller configured to move fluid through at least three second conduits in fluid communication with the second housing; a third pump head disposed between and in fluid communication with the first and second pump heads, the third pump head comprising a third housing containing a third impeller configured to move fluid through at least three third conduits in fluid communication with the third housing, the at least three third conduits in fluid communication with an inlet into the first housing along a first fluid flow path between the first and third pump heads, the at least three third conduits combining fluid flow therethrough to provide a single flow of fluid through the inlet into the first housing, the at least three second conduits in fluid communication with an inlet into the third housing along a second fluid flow path between the second and third pump heads, the at least three second conduits combining fluid flow therethrough to provide a single flow of fluid through the inlet into the third housing; and, a drive structure passing through the inlet into the first housing and the inlet into the third housing, the drive structure configured to commonly drive the first, second and third impellers. [0008] In another aspect, there is provided a fluid pump comprising: a first pump head comprising a first housing containing a first impeller configured to move fluid through at least two first conduits in fluid communication with the first housing; a second pump head comprising a second housing containing a second impeller configured to move fluid through at least two second conduits in fluid communication with the second housing, the at least two second conduits in fluid communication with an inlet into the first housing along a fluid flow path between the first and second pump heads, the at least two second conduits combining fluid flow therethrough at the inlet to provide a single flow of fluid through the inlet into the first housing; and, a drive structure passing through the inlet between the first and second pump heads, the drive structure configured to commonly drive the first and second impellers. [0009] In another aspect, there is provided a pump head for connecting two other pump heads in a fluid pump having at least three pump heads, the pump head comprising: a combiner comprising a fluid chamber in which fluid flow from at least two conduits are combined into a single flow of fluid that flows out of the chamber along a first fluid flow path into an inlet in a first neighboring pump head; a housing containing an impeller configured to move fluid through the at least two conduits in fluid communication with the housing, the housing comprising an inlet for receiving a single flow of fluid along a second fluid flow path from a second neighboring pump head; a drive structure passing through the first and second fluid flow paths connectable to drive structures of the first and second neighboring pump heads, the drive structure configured to commonly drive the impeller with impellers in the first and second neighboring pump heads; the combiner further comprising a first structure connectable to the first neighboring pump head; and, the housing further comprising a second structure connectable to a second neighboring pump head. [0010] In another aspect, there is provided a pump assembly comprising a fluid pump as described above. [0011] The fluid pump comprises two or more pump heads configured in series so that fluid being pumped moves from a reservoir into one pump head and thence to the next pump head in the series, to be eventually discharged from an outlet in a final pump head. Each pump head comprises a housing within which an impeller is contained, the impeller being driven by the drive structure to move fluid. The housing of the pump head comprises an inlet through which fluid is drawn from outside the housing, and the fluid is moved by the impeller from the housing into at least two fluid conduits, preferably at least three fluid conduits, more preferably three or four fluid conduits, to be combined into one fluid flow before exiting the pump head. One or more of the pump heads may comprise a combiner for combining fluid flow from the at least two fluid conduits into a single fluid flow. The combiner may comprise a fluid chamber in which fluid flow from the at least two conduits are combined into the single flow. The fluid chamber of the combiner may comprise openings to permit entry of the fluid from the conduits, and another opening to permit a single outward flow of the fluid from the pump head. The single flow of fluid from one pump head into another defines a fluid flow path between the pump heads. [0012] The drive structure may comprise any one or collection of structures that is configured to impart rotational motion on the impellers. Although more than one power source may be employed, preferably, the drive structure is powered by a single power source, for example a suitable motor. The motor may be, for example, an electric motor, a hydraulic motor, a combustion motor or any other motor that can be configured to drive the drive structure. In one embodiment, the drive structure may comprise one or more drive shafts on which the impellers are mounted. Where there is a single drive shaft, all of the impellers may be mounted on the single drive shaft. Where there are two or more drive shafts, there may be at least one impeller mounted on each drive shaft. [0013] Where there are two or more drive shafts, the drive shafts may be connected through one or more connectors so that one or more of the drive shafts may receive rotational motion from another of the drive shafts. Any one connector may be mounted on two separate drive shafts. Or any one connector may be mounted at one end on a drive shaft and at another end on an impeller, which is mounted on a drive shaft. Or any one connector may be mounted at two ends on separate impellers, which are mounted on respective drive shafts. When a connector is mounted on an impeller, the connector and impeller may form a unitary structure or may be removably connected. Connectors may extend out from the pump heads so that the connector bridges two pump heads and is partially disposed in one or both of the pump heads. In one embodiment, a connector may extend out through the inlet of one pump head. In one embodiment, a connector may extend out through an opening in a combiner of one pump head. In one embodiment, a connector may extend out through the inlet of one pump head and out through an opening in a combiner of a neighboring pump head. In one embodiment, at least a portion of each of the one or more connectors may be in the fluid flow path between respective pump heads. [0014] In one embodiment, any one connector may comprise a sleeve within which one or both of the drive shafts is rigidly mounted to permit transmission of rotational motion from one drive shaft to the other. In one embodiment, one or both of the drive shafts may be frictionally mounted within the connector. In one embodiment, connector may be cylindrical, while in another embodiment the connector may be a tube having a central portion between two end portions, the end portions having larger diameters than the central portion. [0015] Drive shafts within a pump head may extend out from the pump head in one or more directions or may be wholly contained within the pump head. Preferably, the drive shaft does not extend out through the inlet of the housing. Where two drive shafts are connected by a connector, the ends of the drive shafts being connected preferably do not extend outside the pump head. For an initial pump head where fluid is first drawn from a reservoir, the pump head may comprise an impeller having a closed cap configured to seat an end of the drive shaft. [0016] The fluid pump comprises at least two pump heads, for example two, three or four pump heads. The pump heads are disposed in series so that fluid flows sequentially through each pump head of the pump, each pump head being in fluid communication with the pump head before and after in the series. The initial and final pump heads are in direct fluid communication with only one other pump head, the initial pump head drawing fluid from a reservoir in through an inlet in the housing of the initial pump head, and the final pump head expelling fluid out through an outlet of the final pump head. Pump heads may be connected to provide rigidity and a fluid seal between the pump heads. The pump heads may be removably connected or may be formed in a unitary structure. Removable connection of the pump heads permits modularity, thereby facilitating repair should one of the pump heads fail and facilitating the inclusion of more pump heads in the series. Inclusion of more pump heads increases the operating pressure of the pump, which can be tailored by adjusting the number of pump heads in the pump. [0017] As described herein, the fluid pump cannot be constructed by simply stacking known pumps together. The initial and final pump heads have different design features to permit fluid flow from one pump head to the other, while commonly driving the impellers. Intermediate pump heads have design features of both the initial and final pump heads to permit the intermediate pump heads to cooperate with neighboring pump heads to permit series flow of fluid and common driving of the impellers. [0018] A pump assembly comprises a fluid pump mounted on a support structure. The support structure may comprise any suitable apparatus that permits operation of the pump at a fluid reservoir. Some examples of support structures include a wheeled boom, a hitching assembly and a trailer. A wheeled boom may be configured to be towed behind a vehicle, for example a tractor or a truck, and configured to permit submersing the pump into a fluid reservoir. A hitching assembly may be configured to be attached to moveable arms to permit submersing the pump into a fluid reservoir. The hitching assembly maybe associated with a vehicle, for example a tractor or a truck, and the moveable arms powered by a hydraulic system on the vehicle. A trailer may be configured with a trailer bed on which the fluid pump rests, and a submersible pipe in fluid communication with the housing of the initial pump head may be configured to be immersed in a fluid reservoir to permit transfer of fluid from the reservoir into the initial pump head. [0019] Further features will be described or will become apparent in the course of the following detailed description. It should be understood that each feature described herein may be utilized in any combination with any one or more of the other described features, and that each feature does not necessarily rely on the presence of another feature except where evident to one of skill in the art. BRIEF DESCRIPTION OF THE DRAWINGS [0020] For clearer understanding, preferred embodiments will now be described in detail by way of example, with reference to the accompanying drawings, in which: [0021] FIG. 1A is an elevation view of a first embodiment of a fluid pump having two pump heads in series and three fluid conduits per pump head; [0022] FIG. 1B is a top end view of the pump of FIG. 1A ; [0023] FIG. 1C is a side view of the pump of FIG. 1A ; [0024] FIG. 1D is a side cross-section view of the pump of FIG. 1A taken through section A-A shown in FIG. 1B ; [0025] FIG. 2A is an elevation view of one embodiment of an impeller useable in a first pump head of a fluid pump of the present invention; [0026] FIG. 2B is an elevation view of one embodiment of an impeller useable in a second pump head of a fluid pump of the present invention; [0027] FIG. 3A is an elevation view of one embodiment of a combiner for a pump head in a fluid pump of the present invention; [0028] FIG. 3B is a side view of the combiner of FIG. 3A ; [0029] FIG. 3C is a top view of the combiner of FIG. 3A ; [0030] FIG. 3D is a side view of the combiner of FIG. 3A viewed from an angle of 90-degrees with respect to the view in FIG. 3B ; [0031] FIG. 4A is side view of a second embodiment of a fluid pump having three pump heads in series and three fluid conduits per pump head; [0032] FIG. 4B is a top view of the pump of FIG. 4A ; [0033] FIG. 4C is a cross-section view of the pump of FIG. 4A taken through section B-B shown in FIG. 4B ; [0034] FIG. 5 depicts the pump of FIG. 1A mounted on a wheeled boom; [0035] FIG. 6 depicts the pump of FIG. 1A mounted on a hitching assembly; and, [0036] FIG. 7 depicts the pump of FIG. 1A mounted on a trailer. DETAILED DESCRIPTION [0037] FIGS. 1A-1D depict one embodiment of a fluid pump 1 of the present invention comprising two pump heads 10 , 50 arranged in series so that fluid being pumped from a reservoir passes through second pump head 50 into first pump head 10 to be discharged out of first pump head 10 into a desired location, for example into a holding tank. [0038] The second pump head 50 comprises a second housing 51 within which a second impeller 53 is mounted on a second drive shaft 55 . The second drive shaft 55 is parallel to and concentric with a longitudinal axis L of the pump 1 , although an eccentric arrangement may be used, and in some cases the drive shaft may form an oblique angle with longitudinal axis L. The second impeller 53 being driven by rotation of the second drive shaft 55 draws fluid from a fluid reservoir located outside the pump 1 , the fluid entering the second housing 51 through a second inlet 56 (as best seen in FIG. 1D ) in a base 57 of the second housing 51 . The second inlet 56 is ringed by an inlet ring 58 surrounding a perimeter of the second inlet 56 . The inlet ring 58 may be used to mount an immersion pipe to the pump 1 . Fluid flows into the second housing 51 through the second inlet 56 in a single flow in a flow path parallel to a path defined by the longitudinal axis L of the pump 1 . At a periphery of the second housing 51 , three ports lead from an interior of the second housing 51 to three outwardly extending curved second fluid conduits 59 . Fluid flows tangentially and outwardly from the second housing 51 into the second fluid conduits 59 , the fluid thereby being diverted away from the longitudinal axis L of the pump 1 . Fluid flowing in the three second fluid conduits 59 is combined into a single fluid flow at second combiner 61 where the three second fluid conduits 59 meet to form a second chamber 63 through which the longitudinal axis L passes. Fluid from the second chamber 63 passes through a second outlet 65 in a single flow in a flow path parallel to a path defined by the longitudinal axis L of the pump 1 . The single flow of fluid passing out of the second outlet 65 of the second combiner 61 is preferably along the longitudinal axis L, more preferably concentric with the longitudinal axis L. The second housing 51 may further comprise a second housing extension 52 that serves to further enclose the second drive shaft 55 and any seals (e.g. O-rings), bearings or other components of the second pump head 50 . The second housing extension 52 may also serve to support the second combiner 61 to provide extra rigidity and strength. [0039] The first pump head 10 comprises a first housing 11 within which a first impeller 13 is mounted on a first drive shaft 15 . The first drive shaft 15 is parallel to and concentric with a longitudinal axis L of the pump 1 , although an eccentric arrangement may be used, and in some cases the drive shaft may form an oblique angle with longitudinal axis L. The first impeller 13 being driven by rotation of the first drive shaft 15 draws fluid from the second chamber 63 of the second combiner 61 , the fluid entering the first housing 11 through a first inlet 16 (as best seen in FIG. 1D ). Fluid flows into the first housing 11 through the first inlet 16 in a base 27 of the first housing 11 in a single flow in a flow path parallel to a path defined by the longitudinal axis L of the pump 1 . The single flow of fluid passing through the first inlet 16 into the first housing 11 is preferably along the longitudinal axis L, more preferably concentric with the longitudinal axis L. At a periphery of the first housing 11 , three ports lead from an interior of the first housing 11 to three outwardly extending curved first fluid conduits 19 . Fluid flows tangentially and outwardly from the first housing 11 into the first fluid conduits 19 , the fluid thereby being diverted away from the longitudinal axis L of the pump 1 . Fluid flowing in the three first fluid conduits 19 is combined into a single fluid flow at first combiner 21 where the three first fluid conduits 19 meet to form a first chamber 23 . The longitudinal axis L of the pump 1 does not pass through the first combiner 21 or the first chamber 23 . Fluid from the first chamber 23 passes through a first outlet 25 in a single flow in a flow path oblique to, for example perpendicular to, a path defined by the longitudinal axis L of the pump 1 . The first housing 11 may further comprise a first housing extension 12 that serves to further enclose the first drive shaft 15 and any seals (e.g. O-rings), bearings or other components of the first pump head 10 . [0040] The first and second pump heads 10 , 50 are connected to each other so that the second outlet 65 of the second combiner 61 is in direct fluid communication with the first inlet 16 of the first housing 11 . To connect the two pump heads 10 , 50 , the second combiner 61 may be attached to the base 27 of the first housing 11 , for example by bolting, although any sufficiently secure attachment arrangement may be used. [0041] Referring especially to FIG. 1D , the first and second pump heads 10 , 50 are arranged so that the first and second drive shafts 15 , 55 are longitudinally aligned, preferably along the longitudinal axis L of the pump 1 . This arrangement also longitudinally aligns the flow path of the single flow of fluid into the second housing 51 with the flow path of the single flow of fluid into the first housing 11 . In order to commonly drive the first and second drive shafts 15 , 55 , the first and second drive shafts 15 , 55 are connected by a biconical tubular connector 70 . The biconical tubular connector 70 bridges the first and second pump heads 10 , 50 extending through the first inlet 16 , through the second outlet 65 and through the second chamber 63 of the second combiner 61 to frictionally secure one end of the second drive shaft 55 in a hollow interior of the tubular connector 70 . Thus, the tubular connector 70 is within the fluid flow path between the two pump heads 10 , 50 . The tubular connector 70 prevents fluid flowing from the second chamber 63 of the combiner 61 through the first inlet 16 into the first housing 11 from entering into a drive train comprising the tubular connector 70 and first and second drive shafts 15 , 55 thereby protecting the drive shafts 15 , 55 from corrosion and befouling. Frictionally securing the second drive shaft 55 in the tubular connector 70 permits removing the second drive shaft 55 from the tubular connector 70 , which contributes to modularity as the first and second pump heads 10 , 50 are then more easily separated should the need arise for maintenance on one of the pump heads or for inserting more pump heads between the first and second pump heads. [0042] FIG. 2A provides a magnified view of the biconical tubular connector 70 illustrating that in this embodiment, a first end 71 a of the tubular connector 70 is integrally formed with the first impeller 13 to provide extra strength to withstand torsional forces created when the first impeller 13 and tubular connector 70 are rotationally driven by the first drive shaft 15 on which the first impeller 13 is mounted. A second end 71 b of the tubular connector 70 has an opening 72 through which the second drive shaft 55 may be inserted, the second drive shaft 55 being frictionally secured within the tubular connector 70 . The first drive shaft 15 extends out of the first housing extension 12 to be operatively connected to a drive motor (not shown). Driving the first drive shaft 15 with the motor causes rotation of the first drive shaft 15 , thereby causing rotation of the first impeller 13 mounted on the first drive shaft 15 , thereby causing rotation of the tubular connector 70 integrally formed with the first impeller 13 , thereby causing rotation of the second drive shaft 55 frictionally secured in the tubular connector 70 , thereby causing rotation of the second impeller 53 mounted on the second drive shaft 55 , which results in the two impellers 13 , 53 being commonly driven. Thus, the entire drive train is longitudinally aligned with the longitudinal axis L of the pump 1 , and the drive train passes through the fluid flow path of the fluid flowing between the first and second pump heads 10 , 50 . [0043] Still referring to FIG. 1D , second drive shaft 55 has an end that extends into the second housing 51 but does not protrude out of the second inlet 56 . At this end, the second drive shaft 55 is capped with a bell-shaped cap 80 to prevent fluid from entering into the drive train thereby protecting the drive shaft 15 from corrosion and befouling. FIG. 2B provides a magnified view of the bell-shaped cap 80 showing that the bell-shaped cap 80 may be integrally formed with the second impeller 53 . Both FIG. 2A and FIG. 2B illustrate impellers having five arcuate vanes. The first impeller 13 comprises five arcuate vanes 14 (only one labeled) and the second impeller 53 comprises five arcuate vanes 54 (only one labeled). There may be more or less vanes and the vanes may be of another shape, however, such an impeller arrangement as shown in FIG. 2A and FIG. 2B is efficient for moving fluid tangentially outwardly to the ports and thence to the outwardly extending curved fluid conduits. [0044] The second combiner 61 is configured for direct fluid communication with the first inlet 16 of the first housing 11 . As illustrated in FIGS. 1A-1D and FIGS. 3A-3D , the second combiner 61 comprises a mounting plate 67 , which is shaped and configured to be secured to the base 27 of the first housing 11 . The second combiner 61 may also comprise a combiner extension 68 configured to be secured to the second housing extension 52 so that the second combiner 61 may be detached from the second housing 61 . The mounting plate 67 and the combiner extension 68 contribute to modularity and ease of assembly of the second pump head 50 and pump 1 . At the second combiner 61 , the second fluid conduits 59 meet to form second chamber 63 where fluid combines before flowing out through the second outlet 65 . The fluid conduits, including one or both of the first and second fluid conduits 19 , 59 , and any one or more of the fluid conduits for a particular pump head, may be formed in a unitary manner or may be formed of segments of conduits to facilitate assembly of the pump 1 . [0045] FIGS. 4A-4C depict another embodiment of a fluid pump 2 of the present invention comprising three pump heads 10 , 50 , 100 arranged in series so that fluid being pumped from a reservoir passes through second pump head 50 into third pump head 100 and then into first pump head 10 to be discharged out of first pump head 10 into a desired location, for example into a holding tank. [0046] The first and second pump heads 10 , 50 are as described above for the fluid pump 1 . The third pump head 100 is the same as the second pump head 50 , except that third inlet 116 of the third pump head 100 is designed like the inlet 16 of the first pump head 10 . Thus, the third inlet 116 is not ringed by an inlet ring such as the inlet ring 58 on the second pump head 50 . Further, third drive shaft 115 in the third pump head 100 aligns with both the first drive shaft 15 and the second drive shaft 55 , with a third impeller 113 in a third housing 111 of the third pump head 100 comprising a second biconical tubular connector 170 formed as a unitary structure with the third impeller 113 . The second drive shaft 55 is frictionally secured in the second biconical tubular connector 170 . Thus, unlike in the second pump head 50 , the third drive shaft 115 in the third housing 111 of the third pump head 100 is not capped by a bell-shaped cap. Furthermore, the biconical tubular connector 70 , which is integrally formed with the first impeller 13 has an end of the third drive shaft 115 frictionally secured therein. Thus, the entire drive train is collinear along longitudinal axis L′ and all of the impellers may be commonly driven by one motor. One or more additional pump heads identical in construction to the third pump head 100 may be inserted into the series of pump heads to provide a pump with greater operating pressure. [0047] A pump assembly may be formed by mounting a fluid pump of the present invention on a support structure. The support structure may comprise any suitable apparatus that permits operation of the fluid pump at a fluid reservoir. Some examples of support structures include a wheeled boom, a hitching assembly and a trailer. [0048] FIG. 5 depicts the fluid pump 1 described above mounted on a first end of a boom 201 . The boom 201 comprises two sets of wheels 204 mounted on the boom 201 through a wheel frame 205 proximate the first end of the boom 201 to form a wheeled boom. A second end of the boom 201 comprises a towing hitch 206 for securement to a vehicle for transporting the wheeled boom with the pump from location to location. An elongated fluid conduit 202 extending between the first and second ends of the boom 201 is in fluid communication with the outlet of the first pump head 10 and carries pumped fluid from the fluid pump 1 to a tank (not shown) or some other fluid holding apparatus. The outlet of the first pump head 10 is also in fluid communication with agitator nozzle 209 so that a portion of the fluid being pumped is directed through the agitator nozzle 209 to be sprayed back into the fluid reservoir in order to encourage mixing of the fluid in the fluid reservoir. The agitator nozzle 209 is configured to be moveable so that the nozzle 209 may be pointed in a desired direction. [0049] FIG. 6 depicts the fluid pump 1 described above mounted on a hitching assembly 220 . The hitching assembly 220 comprises a pump support 211 on a first end of which the pump 1 is mounted. A second end of the pump support 211 is pivotally mounted on two arms 221 , each of the two arms 221 comprising mounting brackets 224 for mounting the hitch assembly 220 on a vehicle. Hydraulic cylinders 222 actuatable from a cab of the vehicle retract or extend to permit pivoting of the pump support 211 around pivot rod 223 extending between the arms 221 . Pivoting of the pump support 211 permits raising the pump 1 out of a fluid reservoir, or lowering the pump 1 into the fluid reservoir. An elongated fluid conduit 202 extending between the first and second ends of the pump support 211 is in fluid communication with the outlet of the first pump head 10 and carries pumped fluid from the fluid pump 1 to a tank (not shown) or some other fluid holding apparatus. The outlet of the first pump head 10 is also in fluid communication with agitator nozzle 209 so that a portion of the fluid being pumped is directed through the agitator nozzle 209 to be sprayed back into the fluid reservoir in order to encourage mixing of the fluid in the fluid reservoir. The agitator nozzle 209 is configured to be moveable so that the nozzle 209 may be pointed in a desired direction. [0050] FIG. 7 depicts the fluid pump 1 described above mounted on a trailer 230 . The fluid pump 1 rests on a trailer bed 231 , the trailer bed 231 also supporting a motor unit 240 for driving the drive train of the fluid pump 1 . Attached to the inlet ring 58 of the second pump head 50 of the pump 1 is a feed pipe 235 in fluid communication with the inlet into the second pump head 50 . The fed pipe 235 may bifurcate into two immersion pipes 236 , 237 , which can be extended to be immersed in the fluid reservoir to provide two fluid flows into the feed pipe 235 . A vent pipe 238 extending upwardly from the feed pipe 235 and in fluid communication with the feed pipe 235 and open to the atmosphere ensures that pressure in the feed pipe 235 does not become excessive. The motor assembly 240 drives the drive train of pump 1 to draw fluid from the reservoir (not shown) which is ultimately discharged through the first outlet 25 of the first pump head 10 into a fluid conduit (not shown) and then into a holding tank (not shown) or some other fluid holding apparatus. [0051] The novel features will become apparent to those of skill in the art upon examination of the description. It should be understood, however, that the scope of the claims should not be limited by the embodiments, but should be given the broadest interpretation consistent with the wording of the claims and the specification as a whole.

A fluid pump having at least two pump heads in series permits pumping fluid at both high pressure and high volumetric rate. Each pump head has at least two fluid conduits in fluid communication with a housing, the housing containing an impeller for drawing fluid through an inlet in the housing and moving the fluid through the fluid conduits. The at least two fluid conduits of one pump head combine fluid flow at the inlet of a neighboring pump head to provide a single flow of fluid through the inlet into the neighboring pump head. A drive structure passing through the inlets between two pump heads is configured to commonly drive the impellers in the housing of each pump head.

big_patent

TECHNICAL FIELD [0001] This invention relates generally to engine compression release brakes, and more particularly to engines having engine compression release brakes for less than all engine cylinders. BACKGROUND [0002] Traditional engine compression release brake systems typically include an engine brake for each engine cylinder. One such engine compression release brake system is illustrated in U.S. Pat. No. 5,647,318 which issued to Feucht et al. on Jul. 15, 1997. In braking systems such as that disclosed in Feucht et al., the braking horsepower is varied by operating less than all of the engine brakes. However, if the maximum braking horsepower required from the system does not require engine braking using all engine cylinders, the engine includes excess components. Engineers have learned that a reduction in engine components, such as by removal of excess components, can improve the overall robustness of an engine. Therefore, it should be appreciated that an engine compression release brake system including a sufficient, but reduced, number of components would be desirable. [0003] The present invention is directed to overcoming one or more of the problems as set forth above. SUMMARY OF THE INVENTION [0004] In one aspect of the present invention, an engine includes an engine housing defining a plurality of engine cylinders. An engine compression release brake is provided for each of a portion of the engine cylinders, wherein the portion is less than all of the plurality of engine cylinders. [0005] In another aspect of the present invention, a method of engine braking using less than all engine cylinders includes the step of attaching an engine compression release brake to an engine housing for a portion, which is less than all, of the engine cylinders. The portion of engine cylinders is then operated in a braking mode. [0006] In yet another aspect of the present invention, an engine includes an engine housing that defines a plurality of engine cylinders. An engine compression release brake is provided for each of a portion of the engine cylinders, wherein the portion is less than all of the plurality of engine cylinders. Each engine compression release brake being operably coupled to a cam actuated exhaust valve. BRIEF DESCRIPTION OF THE DRAWINGS [0007] [0007]FIG. 1 is a schematic representation of an engine including a modular engine compression release brake system according to the present invention; [0008] [0008]FIG. 2 is a sectioned front diagrammatic view of a cylinder shown in FIG. 1; and [0009] [0009]FIG. 3 is a sectioned side diagrammatic view of the modular engine compression release brake of FIG. 1. DETAILED DESCRIPTION [0010] Referring now to FIG. 1 there is illustrated an engine 10 according to the present invention. A low pressure reservoir 12 is provided in engine 10 and preferably includes an amount of low pressure engine lubricating oil. While low pressure reservoir 12 is preferably an oil pan that has an amount of engine lubricating oil, it should be appreciated that other fluid sources having an amount of available fluid, such as coolant, transmission fluid, or fuel, could instead be used. A high pressure pump 13 pumps oil from low pressure reservoir 12 and delivers the same to high pressure manifold 14 . High pressure oil flowing out of high pressure manifold 14 is delivered via high pressure fluid supply line 15 to a hydraulic system provided in engine 10 , and used oil is returned to low pressure reservoir 12 via low pressure return line 16 after it has performed work in the hydraulic system. An electronic control module 17 is provided by engine 10 and is in control communication with one or more engine components via an electronic communication line 18 . Electronic control module 17 preferably controls multiple aspects of engine 10 operation, such as fuel injection timing and engine compression release brake timing. Engine 10 also provides an engine housing 11 that defines a plurality of engine cylinders 20 . [0011] Each cylinder 20 defined by engine housing 11 has a movable piston 21 . Each piston 21 is movable between a retracted, downward position and an advanced, upward position. For a typical four cycle diesel engine 10 , the advancing and retracting strokes of piston 21 correspond to the four stages of engine 10 operation. When piston 21 retracts from its top dead center position to its bottom dead center position for the first time, it is undergoing its intake stroke and air can be drawn into cylinder 20 via an intake valve. When piston 21 advances from its bottom dead center position to its top dead center position for the first time it is undergoing its compression stroke and air within cylinder 20 is compressed. At around the end of the compression stroke, fuel can be injected into cylinder 20 by a fuel injector 30 , and combustion within cylinder 20 can occur instantly, due to the high temperature of the compressed air. This combustion drives piston 21 downward toward its bottom dead center position, for the power stroke of piston 21 . However, it is known in the art that it is not always necessary, or desirable, for injection and combustion to occur during each cycle of piston 21 . Thus, for those engine cycles, engine compression release braking can occur within engine 10 , as disclosed below. Finally, when piston 21 once again advances from its bottom dead center position to its top dead center position, post combustion products remaining in cylinder 20 can be vented via a cam actuated exhaust valve 35 , corresponding to the exhaust stroke of piston 21 . While engine 10 has been illustrated as a four cycle, six-cylinder engine, it should be appreciated that any desired number of cylinders could be defined by engine housing 11 . [0012] Each cylinder 20 is operably connected to a number of hydraulically and/or mechanically actuated devices. In addition to hydraulically actuated fuel injector 30 and cam actuated exhaust valve 35 illustrated in FIG. 1, other devices could be operably connected to each cylinder 20 , such as an intake valve. Fuel injector 30 is fluidly connected to a fuel source 31 via a fuel supply line 32 and delivers fuel to cylinder 20 for combustion while exhaust valve 35 controls release of combustion remnants after each injection event. In addition, as illustrated in FIG. 1, a portion, but not all, of cylinders 20 each include a hydraulically actuated engine compression release brake 40 that is operably connected to the exhaust valve 35 for the cylinder 20 . While engine 10 has been illustrated having engine compression release brakes 40 connected to four cylinders 20 , it should be appreciated that engine compression release brakes 40 could instead be connected to any suitable number of engine cylinders 20 that is less than the total number of cylinders 20 defined by engine housing 11 . [0013] Referring now to FIG. 2, a cam 29 is provided which is positioned to mechanically engage exhaust valves 35 , preferably via a rocker arm assembly 23 . As cam 29 rotates, a lifter assembly 27 is moved upward about lifter group shaft 28 . Lifter assembly 27 acts upon rocker arm assembly 23 , which includes a rocker arm 24 mounted to pivot about pivot 25 corresponding to rotating movement of cam 29 via a connector rod 26 . Thus, cam 29 can mechanically engage an exhaust valve actuator 37 movably positioned within each exhaust valve 35 via rocker arm assembly 23 . With each exhaust stroke of piston 21 , exhaust valve actuator 37 is driven downward to open cylinder 20 to an exhaust manifold 39 via an exhaust passage 38 defined by exhaust valve body 36 . In addition, for those cylinders 20 having engine brakes 40 , exhaust valve actuator 37 can also be opened during the compression stroke of piston 21 by engine brake 40 , as disclosed below. [0014] Referring in addition to FIG. 3, each engine brake 40 has a brake body 41 and provides an electrical actuator 42 that is preferably a solenoid. However, it should be appreciated that any suitable electrical actuator, such as a piezoelectric actuator, could instead be provided. Solenoid 42 includes a biasing spring 43 , a coil 44 and an armature 45 . Armature 45 is attached to move with a valve member 46 . When solenoid 42 is de-energized, such as when engine braking is not desired, valve member 46 is biased toward its downward position by biasing spring 43 . When valve member 46 is in this position, it opens a high pressure seat 47 defined by brake body 41 and closes a low pressure seat 48 , also defined by brake body 41 . Thus, high pressure fluid can flow around valve member 46 and into a pressure communication passage 52 from a high pressure passage 49 . When solenoid 42 is energized, such as to initiate an engine braking event, valve member 46 is pulled to an upward position by armature 45 against the force of biasing spring 43 . When valve member 46 is in this position, high pressure seat 47 is closed to block pressure communication passage 52 from high pressure passage 49 . Low pressure seat 48 is opened such that pressure communication passage 52 is fluidly connected to a low pressure passage 50 . [0015] Also positioned in brake body 41 is a spool valve member 55 that is movable between an upward, retracted position as shown, and a downward, advanced position. Spool valve member 55 is biased toward its retracted position by a biasing spring 63 . Spool valve member 55 defines a high pressure annulus 57 that is always open to high pressure passage 49 and is positioned such that it can open an actuation fluid passage 67 to high pressure passage 49 when spool valve member 55 is in its advanced position. A low pressure annulus 60 is also provided on spool valve member 55 that can connect actuation fluid passage 67 to a low pressure passage 61 defined by brake body 41 when spool valve member 55 is in its retracted position as shown. Spool valve member 55 has a control surface 64 that is exposed to fluid pressure in a spool cavity 65 , and a high pressure surface 56 that is continuously exposed to high pressure in high pressure passage 44 via a number of radial passages defined by spool valve member 55 . Surfaces 56 and 64 preferably are about equal in surface area, but could be different. Spool cavity 65 is fluidly connected to pressure communication passage 52 . [0016] When pressure communication passage 52 is fluidly connected to high pressure manifold 14 , such as when pilot valve member 46 is in its downward position, pressure within spool cavity 65 is high and spool valve member 55 is preferably hydraulically balanced and maintained in its retracted position by biasing spring 63 . When spool valve member 55 is in this position, actuation fluid passage 67 is blocked from fluid communication with high pressure passage 49 but fluidly connected to low pressure passage 61 via low pressure annulus 60 . Conversely, when pressure communication passage 52 is fluidly connected to low pressure reservoir 12 , such as when pilot valve member 46 is in its first position, pressure within spool cavity 65 is sufficiently low that the high pressure acting on high pressure surface 56 can to overcome the force of biasing spring 63 , and spool valve member 55 can move to its advanced position. When spool valve member 55 is in this advanced position, actuation fluid passage 67 is blocked from low pressure passage 61 but high pressure fluid can flow into actuation fluid passage 67 via high pressure annulus 57 and high pressure passage 49 . [0017] As best illustrated in FIG. 3, a piston 70 is movably positioned in brake body 41 above rocker arm 24 and provides a hydraulic surface 71 that is exposed to fluid pressure in actuation fluid passage 67 . In addition, a lash adjuster 73 is operably coupled to piston 70 via a lash screw 75 . Lash adjuster 73 is preferably sized and positioned to provide sufficient lash to accommodate thermal expansion of the various components when engine 10 warms up, such as from a cold start. When actuation fluid passage 67 is open to low pressure passage 61 , such as when engine braking is not desired, piston 70 remains in its upward, retracted position. However, when actuation fluid passage 67 is open to high pressure passage 49 , high pressure acts on hydraulic surface 71 to move piston 70 toward its downward, advanced position. When piston 70 advances, lash screw 75 comes into contact with exhaust valve actuator 37 and exerts a downward force on an exhaust valve actuator 37 , causing the same to move to an open position against the pressure in cylinder 20 . [0018] Industrial Applicability [0019] Prior to the intake stroke for cylinder 20 , electronic control module 17 has determined if engine braking, rather than fuel injection, is desirable from one or more cylinders 20 . Once it has been determined that engine braking is desirable, a determination is made by electronic control module 17 regarding how much braking horsepower is required. Thus, electronic control module 17 will determine if all cylinders 20 having engine brakes 40 should be operated in a braking mode. Recall, however, that engine 10 according to the present invention provides for a number of cylinders 20 having engine brakes 40 that is less than all engine cylinders 20 . Thus, regardless of the desired braking horsepower a number of cylinders, two for engine 10 as illustrated in FIG. 1, will not be capable of being placed in an engine braking mode. Instead, each cylinder 20 not having an engine brake 40 will under go typical intake and compression strokes of piston 21 during engine braking, but with no fuel injection from fuel injector 30 . Finally, each of the cylinders 20 not having an engine brake 40 can undergo a typical exhaust stroke of piston 21 , wherein exhaust valve 35 is opened by rocker arm. [0020] For illustrative purposes, the operation of only one engine brake 40 , and its respective cylinder 20 , will be described. However, it should be appreciated that each engine brake 40 will operate in a similar manner. Prior to activation of engine brake 40 , solenoid 42 is de-energized such that pilot valve member 46 is in its downward position opening pressure communication passage 52 to high pressure passage 49 . Spool valve member 55 is in its retracted position opening actuation fluid passage 67 to low pressure passage 61 and piston 70 and plunger 75 are in their retracted positions. As piston 20 is retracting for its intake stroke, an amount of air is introduced into cylinder 20 via an intake valve (not shown). As piston 21 reaches its bottom dead center position and begins to advance, air within cylinder 20 is compressed. During typical diesel engine operation, when cylinder 20 was operating in a power mode, fuel would be injected into cylinder 20 at some point during the compression stroke of piston 21 . For instance, for a traditional engine 10 , fuel injection would occur as piston 21 nears the top dead center position for its compression stroke. Conversely, for a homogeneous charge compression engine, fuel injection would occur much sooner during the advance of piston 21 , such as when piston 21 is closer to its bottom dead center position than its top dead center position. However, when cylinder 20 is to be operated in a braking mode, engine brake 40 is activated by electronic control module 17 during the compression stroke of piston 21 . [0021] Just prior to the start of engine braking by cylinder 20 , solenoid 42 is activated by electronic control module 17 and armature 45 pulls poppet valve member 46 upward against the force of biasing spring 43 to close high pressure seat 47 . Pressure communication passage 52 is now blocked from high pressure passage 49 and fluidly connected to low pressure passage 50 . With low pressure fluid acting on control surface 64 in spool cavity 65 via pressure communication passage 52 , the high pressure acting on high pressure surface 56 is now sufficient to move spool valve member 55 downward toward its advanced position against the force of biasing spring 63 . Actuation fluid passage 67 is now blocked from low pressure passage 61 and opened to high pressure passage 49 via high pressure annulus 57 . High pressure in actuation fluid passage 67 acts on hydraulic surface 71 to move piston 70 downward toward its advanced position. As piston 70 advances, lash screw 75 comes into contact with exhaust valve actuator 37 , which is pushed toward its open position against the pressure in cylinder 20 . Compressed air within cylinder 20 can now be vented via exhaust valve 35 . [0022] Once engine brake 40 has been activated for a sufficient amount of time to provide the desired engine braking, electrical actuator 42 is de-energized. Pilot valve member 46 is returned to its biased position opening high pressure seat 47 by biasing spring 43 . Pressure communication passage 52 is now blocked from low pressure passage 50 and opened to high pressure passage 49 . With high pressure again acting on control surface 64 in spool cavity 65 , spool valve member 55 is once again hydraulically balanced, and is returned to its retracted position by biasing spring 63 . Actuation fluid passage 67 is again blocked from high pressure passage 49 and reopened to low pressure passage 61 via low pressure annulus 60 . With low pressure acting on hydraulic surface 71 , piston 70 is returned to its upward, retracted position, allowing exhaust valve actuator 37 to close under the force of biasing spring 71 and the pressure within cylinder 20 . While the various components of engine brake 40 reset themselves, piston 21 continues its reciprocating movement. Piston 21 retracts for its power stroke and then advances for its exhaust stroke. Exhaust valve actuator 37 is reopened by rocker arm to allow removal of the contents of cylinder 20 via exhaust valve 35 . [0023] It should be appreciated that a number of modifications could be made to the present invention. For instance, the poppet and spool valve assembly of engine brake 40 could be positioned above piston 70 , as opposed to the orientation that has been illustrated herein. However, it should be appreciated that the disclosed orientation would find particular applicability where height of engine brake 40 is a concern or limitation. In addition, while engine brake 40 has been illustrated with piston 70 positioned above rocker arm 24 , such that it contacts exhaust valve actuator 37 to move the same to an open position for engine braking, it should be appreciated that alternate orientations are possible. For instance, engine brake 40 could be positioned such that piston 70 is positioned below rocker arm 24 and is capable of lifting rocker arm 24 to an upward position in which exhaust valve actuator 37 is opened for engine braking. It should be appreciated, however, that for this embodiment, modifications to rocker arm assembly 23 might be desirable to prevent rocker arm 24 from disconnecting from connector rod 26 when rocker arm 24 moves independent of cam 29 . Further, while the present invention has been illustrated having four engine brakes 40 utilized with a six cylinder engine 10 , it should be appreciated that it could be used with an engine having any number of cylinders and could include any number of engine brakes that is less than the total number of cylinders and that is capable of providing sufficient engine braking horsepower for engine 10 . [0024] In addition to the above listed modifications, it should be appreciated that any suitable compression release brake structure having, or being modifiable to include, modular characteristics could be substituted for the hydraulically actuated brake that has been illustrated. In addition, the compression release brake could be separate from the exhaust valve, and instead utilize a separate valve member. Indeed, the modularity of the present invention can allow customers to choose, and only pay for, the amount of braking horsepower they desire for a specific application. [0025] It should be understood that the above description is intended for illustrative purposes only, and is not intended to limit the scope of the present invention in any way. Thus, those skilled in the art will appreciate that other aspects, objects and advantages of this invention can be obtained from a study of the drawings, the disclosure and the appended claims.

Traditional engine compression release brake systems include an engine brake that is associated with each cylinder of the engine. However, if the maximum braking horsepower required by the engine is less than that produced using all engine cylinders, the engine includes excess components. In an effort to reduce the number of engine components, and therefore increase engine robustness, the present invention includes an engine compression release brake system that provides a number of engine brakes that is less than the total number of engine cylinders.

big_patent

BACKGROUND [0001] The present invention relates generally to support structures, and more particularly to a mounting link between an engine structure and an attached structure such as an auxiliary gearbox. [0002] Aircraft gas turbine auxiliary gearboxes are expected to withstand a variety of loads, from routine vibrational loads to sudden or extreme shocks caused by hard landings. The most extreme loads come from so-called “blade-off” events, when blades of the engine detach due to impacts or the like, causing severe shocks and often major damage to the working engines. Blade-off event loads are extremely unpredictable, but can be more than an order of magnitude stronger than any other sudden or extreme shock gas turbine engines are expected to experience, such as impacts due to hard landings. Extreme loads can cause damage to the gearbox itself, as well as to attached peripheral systems driven by the gearbox. In addition, extreme loads that damage or disconnect parts of the gearbox from the engine can result in potentially dangerous oil leakages. For all of these reasons conventional gearboxes and gearbox connections are constructed to rigidly withstand all anticipated loads. Often, conventional gearboxes and gearbox connections may require additional material or be heavier to withstand such extreme loads. BRIEF SUMMARY [0003] According to an embodiment, a link assembly between an engine and a gearbox includes a male link coupled to the engine or the gearbox, a female link coupled to the engine or the gearbox, wherein the female link receives the male link to allow translation of the male link relative to the female link and to form a radial interface, wherein the radial interface dampens translation of the male link relative to the female link, and a pin releasably coupled to the male link and the female link to selectively retain the male link and the female link. [0004] According to an embodiment, a gearbox assembly to attach to an engine includes a gearbox, and a link assembly to couple the engine to the gearbox, the link assembly including a male link coupled to the engine or the gearbox, a female link coupled to the engine or the gearbox, wherein the female link receives the male link to allow translation of the male link relative to the female link and to form a radial interface, wherein the radial interface dampens translation of the male link relative to the female link, and a pin releasably coupled to the male link and the female link to selectively retain the male link and the female link. [0005] Technical function of the embodiments described above includes that the female link receives the male link to allow translation of the male link relative to the female link and to form a radial interface, wherein the radial interface dampens translation of the male link relative to the female link, and a pin releasably coupled to the male link and the female link to selectively retain the male link and the female link. [0006] Other aspects, features, and techniques of the embodiments will become more apparent from the following description taken in conjunction with the drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0007] The subject matter is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the embodiments are apparent from the following detailed description taken in conjunction with the accompanying drawings in which like elements are numbered alike in the FIGURES: [0008] FIG. 1 is a perspective view of one embodiment of an auxiliary gearbox for a gas turbine engine; [0009] FIG. 2 is a perspective view of one embodiment of a mounting link for use with the auxiliary gearbox of FIG. 1 ; and [0010] FIG. 3 is a perspective cross-sectional view of the mounting link of FIG. 2 . DETAILED DESCRIPTION [0011] Referring to the drawings, FIG. 1 is a perspective view of a gearbox assembly 10 , which includes a gearbox 12 and supporting elements sufficient to secure the gearbox 12 with respect to the engine 100 . The engine 100 is depicted only schematically, and can, for example, be an aircraft gas turbine engine with a structural engine case, or another engine component to which the gearbox 12 is secured. The gearbox assembly 10 includes driveshaft connection 14 , peripheral load connections 16 and 18 , seal 20 , and mounting links 22 , 24 , and 26 . The gearbox 12 can, for example, be an auxiliary gearbox disposed to transmit torque from the engine 100 to a variety of peripheral loads not directly related to operation of the engine 100 or to propulsion (e.g. to a generator or air circulation system). [0012] A driveshaft connection 14 attaches to a shaft of the engine 100 for torque transmission. The peripheral load connections 16 and 18 are two illustrative auxiliary driveshaft connection points for attachment of peripheral loads to the gearbox 12 . Peripheral loads can include any systems driven by, but not included within, the engine 100 , including but not limited to air circulation systems and electrical generators. Although only two peripheral load connections 16 and 18 are depicted in FIG. 1 , the gearbox 12 can more generally support any number and location of peripheral load connections. [0013] Seal 20 and mounting links 22 , 24 , and 26 collectively constrain the gearbox 12 with respect to the gas turbine engine structure 100 in all six translational and rotational degrees of freedom, without over constraining the gearbox 12 . The seal 20 can for example, be a spigot-type annular seal that constrains the gearbox 12 in two degrees of freedom corresponding to the normal basis of the reference plane on which the seal 20 lies. In the depicted embodiment, mounting links 22 and 26 each provide a single independent degree of constraint, while the mounting link 24 provides two more independent degrees of constraint. More generally, the collection of all linkages connecting the gearbox 12 to the engine 100 including the seal 20 , as well as provides a total of six independent constraints on the translational and rotational freedom of the gearbox 12 with respect to the engine 100 . In alternative embodiments, these constraints can be distributed about more or fewer separate linkages. The independence of these constraints prevents overconstraint (e.g. two links constraining the same degree of freedom) that would necessitate tighter tolerances and could increase damage done to the gearbox and/or the linkages in the event of severe impacts. The locations and number of degrees of freedom constrained by each linkage may vary across different embodiments, so long as the collection of all linkages constrains all six degrees of freedom without significantly overconstraining any. [0014] Referring to FIGS. 2 and 3 , the mounting link 26 is shown. In the illustrated embodiment, the mounting link 26 includes a female link 30 , a male link 32 , and a pin 35 . The mounting link 26 can be utilized as a medium to long link to connect the engine 100 to an associated structure, such as the gearbox 12 , as shown in FIG. 1 . The mounting link 26 can rigidly constrain one degree of freedom between the engine 100 and the gearbox 12 . In the illustrated embodiment, extreme loads may break the rigid constraint of the mounting link 26 by shearing the pin 44 to allow a permitted range of motion. In the illustrated embodiment, the interface between the female link 30 and the male link 32 can dampen the relative motion within the permitted range of motion. Referring to FIG. 1 , the increased and damped mobility of the gearbox 12 relative to the engine 100 allows the mounting link 26 to absorb extreme shocks without either detaching the gearbox 12 from the engine 100 or transmitting potentially destructive loads from the engine 100 to the gearbox 12 . [0015] Referring back to FIGS. 2 and 3 , in the illustrated embodiment, the female link 30 includes a link mounting end 31 and a link interface end 36 . The female link 30 can be formed with any suitable geometry and formed from any suitable material. In the illustrated embodiment, the link mounting end 31 can include a feature to attach or otherwise couple to a component such as the engine 100 or the gearbox 12 as shown in FIG. 1 . In the illustrated embodiment, the link mounting end 31 includes a hole to allow a bolt or feature of a component to pass through to attach the female link 30 to the component. In the illustrated embodiment, the opposite end of the female link 30 is the link interface end 36 . The link interface end 36 includes a cavity to receive the male link 32 . The male link 32 can translate relative to the female link 30 after the pin 44 is broken or otherwise released. [0016] In the illustrated embodiment, the male link 32 includes a link mounting end 33 and a link interface end 34 . The male link 32 can be formed with any suitable geometry and formed from any suitable material. In the illustrated embodiment, the link mounting end 33 can include a feature to attach or otherwise couple to a component such as the engine 100 or the gearbox 12 as shown in FIG. 1 . In the illustrated embodiment, the male link 32 is attached to the corresponding component that female link 30 is not attached to link two components. For example, the female link 30 may be attached to the engine 100 while the male link 32 is attached to the gearbox 12 . In the illustrated embodiment, the link mounting end 33 includes a hole to allow a bolt or feature of a component to pass through to attach the male link 32 to the component. In the illustrated embodiment, the opposite end of the male link 32 is the link interface end 34 . The link interface end 34 is received by the female link 30 in the link interface end 36 of the female link 30 . The male link 32 can translate relative to the female link 30 after the pin 44 is broken or otherwise released. [0017] In the illustrated embodiment, the pin 44 selectively prevents the relative translation of the female link 30 and the male link 32 . In the illustrated embodiment, the pin 44 passes through a through hole 37 of the female link 30 and a through hole 38 of the male link 32 to engage and retain the female link 30 and the male link 32 . In certain embodiments, the through hole 37 of the female link 30 and the through hole 38 of the male link 32 are axially aligned. In the illustrated embodiment, the through hole 37 and the through hole 38 are disposed near the link interface end 36 of the female link 30 and link interface end 34 of the male link 32 . In the illustrated embodiment, the pin 44 can be in an interference fit with the female link 30 and the male link 32 . In the illustrated embodiment, the mounting link 26 can further include a plug 40 . The plug 40 can axially retain the pin 44 . The plug 40 can be disposed or otherwise fit within the through hole 37 in addition to the pin 40 to prevent the unintentional removal of the pin 44 . [0018] In the illustrated embodiment, the pin 44 can serve as a fusible link. In certain embodiments, the pin 44 can shear when a sufficiently strong shock or heavy load is applied. In certain embodiments, a shear plane can be predefined to provide a designated area to allow the pin 44 to shear. In certain embodiments, the pin 44 can be formed of a less durable material than the female link 30 and the male link 32 to facilitate the desired shear characteristics. [0019] In the illustrated embodiment, the pin 44 is designed to shear at a known load magnitude corresponding to the maximum structural capability of the gearbox assembly 12 , the unfused mount components, and the engine mounting structure 100 , as shown in FIG. 1 . This can be accomplished by selecting an appropriately durable diameter and material for the pin 44 , and/or by priming the pin 44 for shear with suitably shaped shear initiation points. In general, the pin 44 must be at least strong enough to withstand peak non-destructive impact loads such as low cycle loads from hard landings and other non-routine but expected shocks. These loads can, for example, reach 10-15 Gs. In at least some embodiments, the pin 44 will not break until loads at least 10-25 times higher than expected low cycle loads are experienced. Very few loads experienced during aircraft engine operation reach these levels, but shocks due to blade-off events can be high enough to shear the pin 44 . [0020] After an event that can cause the pin 44 to shear, fuse, or otherwise release, the female link 30 and the male link 32 are allowed to translate relative to each other. In the illustrated embodiment, the female link 30 and the male link 32 can translate generally axially. Advantageously, mounting link 26 limits or prevents damage that could otherwise be done to gearbox 12 and its attached peripherals by transmitting such extreme loads, while simultaneously helping to prevent gearbox 12 from detaching from engine 100 ( FIG. 1 ). [0021] In the illustrated embodiment, the female link 30 and the male link 32 are in contact at the radial interface 35 between the link interface end 36 and the link interface end 34 . As the female link 30 and the male link 32 translate, the frictional radial interface 35 between the female link 30 and the male link 32 provides coulomb damping to dissipate energy created by the translation. In the illustrated embodiment, the amount of coulomb damping provided by the radial interface is determined by the coefficient of friction, the geometry, and the contact areas of the female link 30 and the male link 32 . In certain embodiments, the materials of the female link 30 and the male link 32 are selected to provide the desired level of coulomb damping. In certain embodiments, the damping force provided by the radial interface 35 is greater than the force required to shear the pin 44 . In other embodiments, the damping force provided by the radial interface 35 is less than the force required to shear the pin 44 . [0022] In the illustrated embodiment, the snap ring 42 can be utilized to limit the relative travel of the male link 32 within the female link 30 . In the illustrated embodiment, the snap ring 42 can be installed after the male link 32 is disposed within the female link 30 to retain the male link 32 at the end of the travel range to prevent the mounting link 26 from separating after the pin 44 is sheared. [0023] Advantageously, the use of the pin 44 and the coulomb damping provided by the radial interface 35 obviates the need for all linkages and peripheral connections to be capable of surviving the extreme loads produced during fan blade-off events, which would otherwise either be entirely infeasible, or would dramatically increase the weight and mass of material required to adequately reinforce associated systems. Fan blade-off events necessitate maintenance to repair or replace damaged engine components, and the pin 44 can be replaced with an intact pin 44 during maintenance following any shock sufficient to break the pin 44 . [0024] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the embodiments. While the description of the present embodiments has been presented for purposes of illustration and description, it is not intended to be exhaustive or limited to the embodiments in the form disclosed. Many modifications, variations, alterations, substitutions or equivalent arrangement not hereto described will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the embodiments. Additionally, while various embodiments have been described, it is to be understood that aspects may include only some of the described embodiments. Accordingly, the embodiments are not to be seen as limited by the foregoing description, but are only limited by the scope of the appended claims.

A link assembly between an engine and a gearbox includes a male link coupled to the engine or the gearbox, a female link coupled to the engine or the gearbox, wherein the female link receives the male link to allow translation of the male link relative to the female link and to form a radial interface, wherein the radial interface dampens translation of the male link relative to the female link, and a pin releasably coupled to the male link and the female link to selectively retain the male link and the female link.

big_patent

BACKGROUND OF THE INVENTION This invention relates to archery equipment and particularly to apparatus and methods for attaching arrow points and nocks to arrow shafts and for balancing arrow shafts. The end adaptor apparatus and balance pin apparatus of the present invention are an improvement over prior art. For example, as known in the prior art, arrow points have a large externally threaded end and are screwed into an arrow shaft having an internal thread. Shortcomings of the prior art are that the shaft's internal threads cause stress to be exerted on the wall of the shaft. Hollow tubes made primarily of unidirectional fibers running the length direction and bonded together with a plastic resin or matrix are prone to split if stressed from the inside and, in particular, if stressed at the end of a tube. A further shortcoming is that when the arrow point is removed, dirt may easily enter the shaft of internal threads through the unsealed end. This affects the weight and balance of the arrow, making it less desirable to use. The present invention solves these and other problems associated with the prior art. SUMMARY OF THE INVENTION It is therefore an object of this invention to provide a small lightweight point cap system that may be adjustable in weight so that perfect balance is easily obtained. In one embodiment, the point cap system comprises a point cap and a balance pin which can be varied in size so as to be of adjustable weight. The present invention provides a point cap system which is small and lightweight and greatly reduces the material and weight of the point or broadhead that may be attached. Light and slim graphite arrows perform and look best with smaller and lighter points than the industry standards. The present invention also relates to a balance pin whose weight can be adjusted to balance an arrow shaft. Further, the present invention provides a point cap and balance pin design which works together. When the balance pin is used (and trimmed to the desired length), the exact point weight may be obtained giving the arrow perfect balance. Also, the present invention relates to means to attach points to arrow shafts without allowing dirt to be able to enter the shaft when the arrow points are not attached. This invention further attempts to have the threads receiving the arrow point placed on a point cap member such that if the threads are damaged, the point cap member may be replaced with a new threaded point cap member. Thus, the more expensive arrow shaft is not rendered useless. The invention also relates to a means of attachment that is suited to the use of unidirectional fiber reinforced shafts. This invention utilizes the strength of the reinforcing fibers by reducing the cross fiber stress at the end of the shaft. The present invention also relates to means for uniformly encapsulating or capping the end of an arrow shaft with a material that has nearly the same strength properties in all directions like steel or aluminum. One embodiment of the present invention also relates to a point adaptor adhesively attached to the arrow shaft and having internal threads for threaded receipt of various types of arrow points having external threads. The present invention also relates to a nock cap adaptor for attaching nocks to the end of an arrow shaft. These and various other advantages and features of novelty which characterize the invention are pointed out with particularity in the claims annexed hereto and forming a part hereof. However, for a better understanding of the invention, its advantages, and its objects obtained by its use, reference should be made to the drawings which form a further part hereof, and to the accompanying description matter, in which there is illustrated and described a preferred embodiment of the invention. BRIEF DISCUSSION OF THE DRAWINGS In the drawings, wherein like reference numerals indicate corresponding parts throughout; FIG. 1 is an enlarged sectional view of one embodiment of a point cap in accordance with the principles of the present invention; FIG. 2 is a sectional view illustrating attachment of a field point to an arrow shaft by use of the point cap in accordance with the principles of the present invention; FIG. 3 is an enlarged sectional view of one embodiment of a point adaptor in accordance with the principles of the present invention; FIG. 4 is a sectional view illustrating attachment of a broadhead to an arrow shaft by use of the point adaptor shown in FIG. 3; FIG. 5 is an enlarged sectional view of one embodiment of a nock cap in accordance with the principles of the present invention; FIG. 6 is a sectional view of one embodiment of a balance pin attached to an arrow point and inserted into an arrow shaft in accordance with the principles of the present invention; and FIG. 7 is a sectional view illustrating an embodiment of an arrow shaft including the point cap and the balance pin. DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, where like numerals apply to like parts, and more particularly to FIG. 1, an embodiment of an end adaptor, herein referred to as a point cap, 100 may be seen. The point cap 100 is an integral, one-piece unit which includes an externally threaded end 101, to which an arrow point, such as a target point, a field point, or a broadhead point, with cooperating internal threads may be secured as generally indicated in FIG. 2, wherein a field point 110 is shown attached to an arrow shaft 104 via the point cap 100. In the preferred embodiment, the point cap 100 is made from a hardened steel. An opposite end portion 103, also referred to as a ferrule end, of the point cap 100 forms a cylinder with a hollow interior 102. Hollow interior 102 has a diameter such that the point cap slides over and is suitably affixed to the arrow shaft 104. The arrow shaft 104 shown in FIG. 2 is hollow and has a bore 105. In the preferred embodiment, the arrow shaft is made of graphite, glass or similar unidirectional reinforcing fibers. The point cap 100 may be affixed to the arrow shaft using an epoxy. The point cap 100 might include identification grooves 106 for identifying varying configurations of point cap as may be used with varied sizes and configurations of arrow points, shafts, etc. The use of an externally attached point cap provides additional support to the end of the arrow shaft. The terminology ferrule, as used herein, refers to a bore with surrounding cylindrical wall portion providing additional support to the shaft it cooperates with. As opposed to internal threads for arrow point attachment, the use of external threads at the end of a cap is ideal for graphite shafts because stress is reduced at the end of the shaft. Preferably, the point cap is permanently attached to the arrow shaft; however, in some embodiments the point cap might be attached with a less permanent adhesive such that if the threads are damaged, the point cap may be replaced with a relatively inexpensive new point cap, thereby preventing the loss of the more expensive arrow. In the preferred embodiment, the threaded end 101 has a lesser outside diameter than the outside diameter of the end portion 103 and the outside diameter of the arrow shaft 104. At the junction of the threaded end 101 and the end portion 103, the end portion 103 is circumferentially surrounded by an inclined surface 109 for cooperating with a similarly inclined surface of an arrow point. Illustrated in FIG. 3 is an embodiment of an internally threaded point adaptor 120 in accordance with the principles of the present invention. The point adaptor 120 is an integral, one-piece unit which includes a first end 122 including an internally threaded portion 124 and a hollow cylindrical bore portion 126. A second end 128 has an externally tapered surface and a bore configured for receipt of the arrow shaft 104, as generally illustrated in FIG. 4. The first and second ends 122,128 are interconnected by a passageway 130 to allow the escape of air upon insertion of the arrow shaft 104 into the bore of the second end 128. In FIG. 4, a broadhead arrow point 111 is illustrated as being threaded into the threaded portion 124, a threaded portion 132 of the broadhead arrow point cooperating with the threaded portion 124 of the point adaptor 120. The broadhead arrow point 111 is shown further including a cylindrical portion 134 slidably received in the bore portion 126 of the point adaptor 120. The point adaptor 120 is preferably made of a light material such as aluminum. As illustrated in FIG. 4, the point adaptor 120 is preferably attached to the arrow shaft 104 by an adhesive 136 such as epoxy. In FIG. 4, the arrow shaft 104 is illustrated as being hollow, although it will be appreciated that the arrow shaft might also be solid. The point adaptor 120 might further include identifying grooves 138 for identifying differing configurations and sizes of the point adaptor 120. Illustrated in FIG. 5 is an embodiment of a nock cap 140 in accordance with the principles of the present invention. The nock cap 140 includes a first hollow cylindrical end 142 for slidable receipt on the arrow shaft 104 and a hollow tapered end 144 for insertion into a bore of a nock 145, as generally illustrated in FIG. 4. The nock cap 140 provides fluid communication between its ends such that upon insertion of the nock cap 140 onto an end of the arrow shaft 104, air can escape from the nock cap 140. The nock cap 140 is preferably made of a light material such as aluminum and is attached to the arrow shaft by an adhesive 146. The nock cap 140 might further include identifying grooves 148 as in the case of the point adaptor 120. The nock 145 is preferably made of a light material such as plastic and is attached to the nock cap 140 by an adhesive 150. FIG. 6 refers to a balance pin 207 which may be used with an arrow point such as a target point 201. The balance pin 207 is affixed to the arrow shaft 104 by insertion into the arrow shaft 104 without necessitating the use of a threaded arrow shaft. A head portion 202 of the balance pin 207 is bonded to the interior of the arrow point 201 by adhesive 206. A shaft portion 203 of the balance pin 207 is inserted into the bore 105, of the arrow shaft 104. Preferably, the balance pin 207 is made of a heavy, soft metal such as brass, such that the balance pin shaft 203 may be cut off or trimmed to obtain a desired point weight. In the preferred embodiment, the balance pin 207 is an integral, one-piece unit. The balance pin 207 may also be used with a point cap by binding the balance pin to the interior of the point cap 100. In this way, it is possible to adjust the point weight. The point cap 100 is used with an arrow shaft by suitably affixing the ferrule end 103 of the point cap 100 to the arrow shaft 104. An arrow point, such as a target point or broad head may be then threadedly attached to the point cap. The balance pin 207 may be used with an arrow point having a hollow interior by affixing the head portion 202 of the balance pin 207 to the hollow interior of field point 201 by placement of an adhesive between the head portion of the balance pin and the arrow point or point cap. The shaft 203 of the balance pin is then inserted into the arrow shaft bore 105. To prevent movement or vibration of the end cap in the arrow shaft, a small amount of adhesive might be placed on the shaft of the balance pin. As illustrated in FIG. 7, the balance pin 207 may be used with the point cap 100 by suitably affixing the head portion 202 of balance pin 207 in the bore 102 of the ferrule end 103 of the point cap 100. The point cap 100 is then attached to the arrow shaft 104 such that the balance pin shaft 203 is in the interior of the arrow shaft 104. It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.

An arrow end adaptor and a balance pin for an arrow and a method for making the same. The arrow comprising a ferrule having a large enough inner diameter to be placed over the arrow shaft, and further having an exterior threaded end whose diameter is smaller than the diameter of the arrow shaft. The point cap is designed such that an arrow point having interior threads may be attached to the exterior threaded end of the point cap. The balance pin is designed to have a head at one end that may be affixed to either a target point or a point cap and a shaft end that may be inserted into the arrow shaft.

big_patent

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to military weapons and particularly to apparatus for simulating the sound and flash thereof. More particularly, the present invention may be described as an electronically controlled pyrotechnic sound and flash simulator for use with small arms training. 2. Description of the Prior Art In recent years, the armed forces have placed an increasing emphasis on the realism of battlefield training conditions. In U.S. Pat. No. 3,836,919 entitled "Small Weapons Noise Simulator," which issued June 3, 1958 to Edwin R. DuBois, there is shown an electro-mechanical small weapons noise simulator which can be attached to a weapon. Currently with regard to the standard M16 automatic weapon, the armed forces use blanks and a blank fire adapter. The sound levels produced by this method are far below that of live round fire. Inasmuch as each M16 blank is estimated to cost at least 8.5 cents, training with such is quite expensive. SUMMARY OF THE INVENTION The present invention represents a cost effective means for simulating small arms fire without modifying the weapon and without the use of mechanical actuation, other than in electrical switches. The present invention utilizes a low cost plastic expendable housing a metal/oxidizer pyrotechnic in conjunction with an electrical ignition system. The expendable would contain a plurality of rounds and would be installed in a firing unit which can be inserted into the weapon via the magazine breech. The invention produces sound and flash by the electrical ignition of the pyrotechnic in a confined space and venting the combustion produced in a manner which utilizes the weapon's ejection port. The electrical control circuit provides for automatic and semiautomatic fire, and interfaces with the weapon trigger and bolt. It is an object of this invention to provide a realistic simulation of small arms fire noise and flash. Another object of the invention is to provide an inexpensive means to provide realistic training using an actual weapon. Yet another object of the invention is to provide a reliable, low maintenance, reusable small arms training device. Another object of the present invention is to provide a pyrotechnic simulation of small arms fire without dangerous pressuration of the ignition chamber. The foregoing and other objects, features and advantages of the invention, and a better understanding of its construction and operation, will become apparent from the following detailed description taken in conjunction with the accompanying drawings. DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of the electrical control circuit; FIG. 2 is a schematic diagram of the electrical control circuit; FIGS. 3a and 3b are an illustration of the expendable; and FIG. 4 is an illustration of the expendable within the firing unit. DESCRIPTION OF THE PREFERRED EMBODIMENT The circuitry of the Small Arms Firing Effect Simulator (SAFES) consists of ten functional blocks as shown in FIG. 1, plus battery and expendable as shown in FIG. 3. Referring to FIG. 1, the embodiment shown in the block diagram utilizes a bolt interface 10, a trigger interface 20, an oscillator control 30, a 500 Hertz oscillator 40, a 10 Hertz oscillator 50, a firing counter 60, firing decoder 70, firing control 80, firing sensors 90, and a Multiple Integrated Laser Engagement System (MILES) interface 19. The implementation of the functional block diagram is shown in FIG. 2 utilizing seven CMOS IC's, thirty-one SCR's, five diodes, six capacitors, seventy-four resistors, and three switches. The bolt interface 10 is constructed to provide a realistic simulation of operator actions as would occur during the firing of live rounds. This is accomplished through a microswitch 101 that engages the weapon's bolt as it travels. As shown in FIG. 2, switch 101 is connected to relay 102 and resistor 103. When the weapon bolt is open, or the SAFES unit is out of the weapon, switch 101 is closed, allowing relay 102 contacts to open. With relay 102 open, pyrotechnic charges 11 cannot be fired, a safety precaution which duplicates the action of the weapon. When the ganged selector switches 208 and 209 are turned to the "Semi" or "Auto" position, the R-C combination of resistor 104 and capacitor 105 resets a bolt flip-flop 106. Flip-flop 106 provides signals to the oscillator control circuit 30 and the firing counter 60, inhibiting their action. Flip-flop 106 is set by the action of microswitch 101, which is debounced through the use of resistor 102 and a capacitor 107 in conjunction with a Schmitt trigger 108. Trigger interface 20 utilizes a resistor 201, a resistor 202, a capacitor 203, a Schmitt trigger 204, and a dome switch 205, which is normally open. The action of switch 205 is debounced by the R-C time constant of resistor 202 and capacitor 203. The fall in voltage is detected by Schmitt trigger 204 and when triggered, the output of Schmitt trigger 204 goes high. Schmitt trigger 204 has its output connected to the semi position of selector switch 208 and to an input to a NAND gate 501 in 10 Hertz oscillator 50. Oscillator control 30 uses a D flip-flop 301, a NAND gate 302, and an inverter 33. Flip-flop 301 is clocked by the signal from trigger interface 20 when selector switch 208 is in the semi position, and by the output of 10 Hertz oscillator 50 in the auto position. The level of the input to flip-flop 301 from bolt interface 10 determines the state of the output to 500 Hertz oscillator 40 when flip-flop 301 is clocked. If bolt actuation has taken place, 500 Hertz oscillator 40 is enabled. Flip-flop 301 is reset, inhibiting 500 Hertz oscillator 40, only by a signal from firing sensor 80. NAND gate 302 serves to control the output of 500 Hertz oscillator 40 and provides CLK signals used as timing pulses by firing counter 60 and firing decoder 70. Inverter 303 is used to invert part of the CLK signal to CLK signal, which is also used by firing counter 60 and firing decoder 70. 500 Hertz oscillator 40 is comprised of a NAND gate 401, an inverter 402, resistors 403 and 404, and a capacitor 405. The input to NAND gate 401 comes from flip-flop 301, with the other input to gate 401 tied to ground via resistor 404 and capacitor 405. When the input from flip-flop 301 is high, 500 Hertz oscillator 40 runs; when the input is low, oscillator 40 is inhibited. The running frequency of oscillator 40 is determined by the values of resistor 403 and capacitor 406. Resistor 404 provides feedback to allow NAND gate 401 to change states. The output of gate 401 is inverted by inverter 402 and input to NAND gate 302. 10 Hertz oscillator 50 utilizes NAND gates 501 and 502, resistors 503 and 504, and capacitor 505. NAND gate 501 is controlled by the signal input from inverter 204 of trigger interface 20. When said signal is high, that is, when the trigger is squeezed, 10 Hertz oscillator 50 operates. The values of resistor 504 and capacitor 505 determine the running frequency. Resistor 503 provides the feedback required to allow NAND gate 501 to changes states. The output of gate 501 serves as the input to gate 502, which has its output connected to the auto position of switch 208, thus reclocking flip-flop 301 at a 10 Hertz rate in the auto mode. Firing counter 60 consists entirely of a dual binary counter, such as a MC14520. Counters 601 and 602 are held in a reset mode until the actuation of bolt interface 10. A low signal from flip-flop 106 enables counters 601 and 602 to accumulate the CLK and CLK signal, respectively. The outputs of each counter is then fed into one-half of firing decoder 70. Firing decoder 70 of FIG. 1 consists of firing decoders 701 and 702. Firing decoders 701 and 702, as shown in FIG. 2, are two 4-bit latch/4 to 16 line decoders, such as MC14514's. Decoder 701 receives the count from the CLK counter 601 and decodes it to provide a single pulse on the appropriate line of the sixteen outputs. Decoder 702 performs the same function, but receives its input from CLK counter 602. The outputs of decoders 701 and 702 are connected to the gate resistors 901 through 963 of firing control 90. The outputs of decoders 701 and 702 are inhibited by a signal derived from oscillator control circuit 30, thus providing a means of stopping the drive to firing control 90 while maintaining the decoded count. Firing control 90 utilizes thirty-one SCR's of the MCR-106 type, and sixty-two gate resistors. Resistors 901 through 963 are placed in pairs between ground and firing decoder 70 at the gate of each SCR 965 through 995. This is to limit the gate current required from decoders 701 and 702 and to provide temperature stability against false triggering. The anodes of the odd numbered SCR's 965 through 995 are connected to the contact of relay 102. The cathodes of odd numbered SCR's 965 to 995 are connected to the appropriate side of each pyrotechnic charge 11. The even numbered SCR's 966 to 994 have their cathodes tied to ground and their anodes tied to one side of their appropriate charge 11. When relay 102's contacts are closed, SCR's 965 to 995 can be triggered by firing decoders 70. The trigger timing is controlled such that only two SCR's are enabled at any time, thus current can only flow through one charge at a time. Each SCR 965 to 995 is triggered until an unexpended charge is found, then the triggering stops until the next fire command is given. Firing sensor 80 consists of diodes 801, 802, and 803, a voltage comparator 804, capacitor 806, resistors 807, 808, 809, and 811, and inverter 805. These components are connected to provide a signal to oscillator control 30 and a MILES interface at the moment a charge 11 fires. This was accomplished by placing diodes 801 and 802 in the current path which supplies SCR's 965 to 995. The voltage across diodes 801 and 802 is monitored by voltage comparator 804. When current flows through the diodes, firing control 90 has sequenced to an unexpended charge. The resultant voltage drop across the diodes is sensed and forces the output of comparator 804 high. This output is inverted by inverter 805 and used to reset oscillator control flip-flop 301, turning off 500 Hertz oscillator 40. MILES interface 19 is simply a diode 19, whose cathode is connected to the output of firing sensor 80, connected to the trigger of the MILES unit associated with the weapon. The particular firing control circuitry shown in FIG. 1 and described hereinabove is for a 30-round magazine insert for use in training combat troops with an M16 rifle with a MILES unit attached thereto. To further enhance the realism, the small arms firing effect simulator is packaged to resemble the magazine clip of the M16. Referring to FIG. 3, the small arms firing effect simulator is packaged within a reusable housing 21 having an upper end 211 and a lower end 212. Upper end 211 is designed for insertion into an M16 in the manner of a magazine clip, said upper end 211 having an exhaust port 213 designed for cooperation with the ejection port of said M16 rifle. Exhaust port 213 communicates with lower end 212 via an upper exhaust chamber 214 with upper end 211. Within upper exhaust chamber 213 is port spring 215 designed to maintain reusable housing 21 in cooperative relation within said M16 rifle. Within upper end 211, switch 101 of bolt interface 10 is positioned for cooperation with the bolt of said M16. Also within upper end 211 is a battey compartment 216 for housing power supply 207. Lower end 212 houses the electric control circuitry and the plastic expendable 12 which contains pyrotechnic charges 11. A lower exhaust chamber 217 communicates with upper exhaust chamber 214 to provide a path for the discharge of gases generated by the explosion of pyrotechnic charges 11. Selector switch 208 is mounted on lower end 212, as is trigger overlay 218 for connecting trigger interface 20 to the weapon. Plastic expendable 12 is mounted within a hinged chamber block 219 which forms lower exhaust chamber 217 and holds expendable 12 in place in a receiver block 220. Receiver block 220 has contact pins 221 which serve to connect firing control 90 with pyrotechnic charges 11. Plastic expendable 12 is designed to be fabricated in an automatic process, thereby reducing cost. The configuration of expendable 12 is as shown in FIG. 4. Expendable 12 is a series of thirty cups 121, with bridge wire 111 at the bottom of each cup 121. Bridge wire 111 makes contact to a silk-screened conductive area 122 between each cup 121. Conductor area 122 makes contact with contact pins 221, thus connecting to firing control 90. Referring to FIG. 3, each cup 121 has within it a pyrotechnic charge 11 which is a shaped pyrotechnic pellet composed of 75% potassium perchlorate, 15% black powdered aluminum, and 10% dextrose. Each pellet is sealed within a cup 121 by a plastic sealant 124 such as RTV silicone. The entire expendable structure is encased in a plastic casing 126. The concept behind the small arms firing effect simulator is that of an electrical ignition of pyrotechnic charge 11 by heating bridge wire 111 to incandescence. Charge 11 burns in a combination mode to produce a quantity of combustion by-products, which, being contained in a fixed volume, produces a rapid increase in pressure. At some point, the pressure will be great enough to rupture plastic sealant 124 covering the exit orifice. The shock of the rupture and the ensuing venting of pressure from chambers 214 and 217 via exit port 211 produces overpressure levels and duration which simulate small arms fire. While the invention has been described with reference to a preferred embodiment, it will be appreciated by those skilled in the art that additions, deletions, modifications, and substitutions or other changes not specified may be made which will fall within the purview of the appended claims.

A small arms firing effects simulator utilizes a modular construction to egrate with the magazine of a weapon such as a rifle. The modular design resembles the ammunition clip and houses an expendable plastic coated plurality of pyrotechnic charges. An electrical control circuit is also housed within the module and serves to interface the pyrotechnic charges with the firing of the weapon, including semi-automatic and automatic firing as well as disabling the weapon when all rounds have been fired.

big_patent

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air intake device of an internal combustion engine. 2. Description of the Prior Arts An air intake device of an internal combustion engine that utilizes the dynamic effects of the air flow to improve the volumetric efficiency of the engine is known, for example, from Japanese Examined Patent Publication No. 47-43374 issued on Nov. 2, 1972 and Japanese Unexamined Patent Publication No. 55-87821. This known device comprises a tank providing a volumetric area extending along an intake tube, a valve disposed in an interconnecting portion between the tank and the intake passage, and valve activating means to open or shut the valve in response to the engine load. This arrangement makes it possible to enhance engine perfomance. Analysis of the effect of such a device has determined that an air inlet pipe placed upstream of an air cleaner should be as short as possible, to obtain the most enhanced dynamic effect. However, it has been also determined that there is an increase in the noise from the air intake if the inlet pipe upstream of the air cleaner is cut too short. SUMMARY OF THE INVENTION It is an object of the present invention to provide an air intake device of an internal combustion engine that will improve the performance of the engine by the best utilization of the dynamic effect, to reduce noise from the air intake. According to the present invention, an intake device for an internal combustion engine having an air intake passage extending from an air cleaner to an intake manifold comprises a tank defining a volume, a first pipe defining a first passage interconnecting the tank with the air intake passage, and a second pipe defining a second passage interconnecting the tank with the air intake passage. The first and second passages are open to the intake passage at different locations with respect to each other, and the cross-sectional area of the second passage is smaller than that of the first passage. A valve is disposed in the first passage together with a valve actuating means responsive to an engine operating condition. Preferably, the cross-sectional area of the first passage is equal to or larger than that of the intake passage, and the cross-sectional area of the second passage is substantially equal to or smaller than about one-tenth that of the first passage. The second passage preferably opens to the air intake passage at a location nearer the air cleaner than the location where the first passage opens to the air intake passage. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be more fully understood from the following description of the preferred embodiment, with reference to the attached drawings, wherein: FIG. 1 is a schematic sectional view of an air intake device of an internal combustion engine according to the present invention; FIG. 2 is a graph illustrating volumetric efficiency curves with respect to the engine speed; FIG. 3 is a graph illustrating sound pressure level curves with respect to the engine speed; FIG. 4 is a graph similar to FIG. 2 for further illustrating the valve operation; FIG. 5 is a graph of the volumetric efficiency curves with respect to the engine load; and FIG. 6 is a graph illustrating the region where the valve is operated. DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 1, an air cleaner 1, an intake tube or pipe 2, and an intake manifold 3 are connected in series and constitute a conventional air intake passage wherein the air flows in the direction indicated by the arrow F to an engine 100. According to the present invention, a tank 4 providing a constant volume is extended along the intake pipe 2. The tank 4 and the intake pipe 2 are interconnected by two pipes 5 and 6. The cross-sectional area of the pipe 5 (represented by the diameter L) is substantially equal to or larger than that of the intake pipe 2 (represented by the diameter L'). The pipe 6 is located upstream of the pipe 5, i.e., is connected between the tank 4 and the intake pipe 2 at a position nearer the air cleaner 1 than a position where the pipe 5 opens to the intake pipe 2, and has a smaller cross-sectional area (represented by the diameter L") than the pipe 5. The ratio of the cross-sectional area between both pipes 5 and 6 is preferably about one tenth, wherein the diameter L of the pipe 5 is about 60 mm and the diameter L" of the pipe 6 is about 20 mm. These two pipes 5 and 6 define air passages between the tank 4 and intake pipe 2, respectively. A control valve 7 is disposed at the tank-side opening of the passage defined by pipe 5, this valve 7 being actuated by an actuator 8 comprising a vacuum diaphragm actuator, wherein the actuator 8 has a diaphragm 8a mounted in a casing 8b. The valve 7 is fixed to the diaphragm 8a by a valve rod 8c. The apparatus has a vacuum chamber 8d defined by the diaphragm 8a and the casing 8b. A compressed spring 8e urges the diaphragm 8a in the direction toward which the valve 7 is closed. When a vacuum is introduced into the vacuum chamber 8d, it causes the valve 7 to open against the spring 8e. The vacuum is supplied from a vacuum tank 11 through a solenoid valve 12, which is controlled by a controller 13. The controller 13 produces a control signal for the solenoid valve 12, based on an input representing the engine load conditon, such input being delivered by, for example, an engine speed sensor 14 and a throttle position sensor 24. The solenoid valve 12 allows the vacuum chamber 8d to communicate with the vacuum tank 11 when the valve 7 is to be opened, and allows the vacuum chamber 8d to connect to the atmosphere when the valve 7 is to be closed. The vacuum tank 11 can be connected to the intake manifold 3, as a vacuum source, through a check valve 15. A throttle valve 18 is located in the intake pipe 2 near the intake manifold 3. The fuel supply means can be of any conventional type. In the preferred embodiment, a fuel injector 20, a so-called unit injector type, is arranged in the intake pipe 2 between the throttle valve 18 and the opening of the pipe 5. FIG. 2 shows two typical volumetric efficency curves A and B with respect to the engine speed. It will be understood by a person skilled in the art that a volumetric curve such as that shown by A or B changes in accordance with the effective pipe length between a convergent end 9 of the air cleaner 1 (through intake pipe 2) and the intake manifold 3, depending on a specific engine design, because the volume of the tank 4 and of the passage in the pipe 5 serves to change the effective length of the intake pipe 2. Curve A is a typical representation of the volumetric efficiency when the valve 7 is closed, whereas curve B is a typical representation of the volumetric efficiency when the valve 7 is opened. Thus, it will be understood that the engine performance is improved if the control valve 7 is controlled as indicated in FIG. 2 to create a new compound curve comprising each peak portion of the curves A and B. As mentioned previously, such features can be best attained by decreasing the length of an air inlet pipe or nose 10 placed upstream of the air cleaner. The length from the open end of the pipe 10 to the air cleaner is preferably 10 cm. However, this results in an increase in the air intake noise. An object of the present invention is to decrease this noise while improving the engine performance. FIG. 3 shows curves representing the sound pressure level of the intake noise with respect to the engine speed. As shown by the curve D, the noise is increased when the valve 7 is closed, since the noise is absorbed by the volume of the tank 4 to some extent when the valve 7 is open. This noise can be reduced to the level indicated by the curve E, i.e., within the permissable level C, by the provision of the narrow passage of the pipe 6. As is apparent, the volume of the tank 4 and the narrow passage of the pipe 6 constitute a resonator which absorbs the noise. The resonator effect can be determined by the relationship given in the following equation, ##EQU1## where, f=frequency of the intake noise, c=speed of the sound, s=cross-sectional area of the passage in the pipe 6, l=length of the passage in the pipe 6, V=volume of the tank 4. It is obvious that the provision of the narrow pipe 6 interconnecting the tank 4 with the intake pipe 2 constitutes a resonator rather than a device to influence the dynamic efficiency, if the cross-sectional area of the passage in the pipe 6 is smaller than that of the pipe 5. However, the provision of the narrow passage in the pipe 6 may have an influence on the dynamic effect, to a small extent, depending on the size of the pipe 6. For this reason, it is preferable to locate the pipe 6 at a position adjacent to, or as near as possible to, the air cleaner 1. The operation of the valve 7 is now further described. FIG. 4 shows similar volumetric efficiency curves A and B to those of FIG. 2. Curve B has two peaks at engine speeds N 1 and N' 1 within an accessible engine operating range for a conventional car. Curve A has a peak at engine speed N 2 between the speeds N 1 and N' 1 , and a further peak at engine speed N' 2 , which does not appear within the accessible engine operating range in this embodiment. The valve 7 is turned to open or to close, as shown in FIG. 2, at engine speed N X and N Y where the two curves A and B intersect. These characters N 1 , N' 1 , N 2 , N X , and N Y are used in a similar sense in FIGS. 5 and 6. Note the characteristic of curves A and B is best obtained when the engine load is maintained at a constant value, near to its full load, and the curve B becomes closer to curve A when the load changes. This feature is explained in reference to FIG. 5, which shows curves F and G with respect to the engine load when the engine speed is constant at N 1 and N 2 , respectively. The solid line shows when the valve 7 is closed and the broken line shows when the valve 7 is opened. It will be seen that the difference between the solid line and the broken line becomes smaller as the engine load becomes smaller, and, such difference becomes substantially zero below a load r 1 or r 2 . Such points as N 1 to r 1 and N 2 to r 2 are plotted to make a line n in FIG. 6. It will thus be understood that the valve 7 is preferably closed at any engine speed when the load is below the line n. When the load is above the line n, the valve 7 is operated in a manner as shown in FIG. 2. More preferably, the valve 7 is opened only in the region where the load is above the line n and the speed is above N Y , since the lefthand opening zone rarely appears in actual engine operations. These valve operating conditions can be stored as a map in the control circuit 13 in FIG. 1, which produces a control signal for the solenoid valve 12 and thus the control valve 7, based on the engine speed sensor 14 and the throttle position sensor 24. It will be apparent to those skilled in the art that the engine load is often detected by the position of the throttle valve 18. The load can be also detected by other means, for example, the vacuum level in the intake manifold 3.

An air intake device of an internal combustion engine having an intake passage comprises a tank which extends along the intake passage. A first pipe interconnects the tank with the intake passage and a valve disposed therein is actuated in response to the engine speed for improving the engine performance. A narrow second pipe also interconnects the tank with the intake passage and constitutes a resonator in conjunction with the tank. The second pipe opens into the intake passage upstream of a throttle valve and preferably close to an air cleaner mounted on the upstream end of the intake passage.

big_patent

BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to a bracket for use in mounting speakers or other equipment to a pole, flat surface, or other structure. In particular, the invention relates to a two-part bracket that allows simple mounting of the equipment to the mounting surface by connecting the two parts of the bracket together. 2. The Prior Art In order to mount a speaker or other object onto a pole, a pipe clamp is commonly used. The pipe clamp contains a U-bolt that is specifically sized for a single pipe diameter. The U-bolt usually has threaded ends for nuts to provide an extreme clamping force against the pole. One disadvantage of this type of system is that it requires a different pipe clamp for each size of pole. Another disadvantage is that the installer is required to hold the speaker or other object in place and to tighten the bolts at the same time. This operation thus usually requires two people for installation. SUMMARY OF THE INVENTION It is therefore an object of the invention to provide a mounting bracket that can be used to install a speaker or other object on a variety of surfaces of different sizes. It is another object of the invention to provide a mounting bracket that can be used by one person to install the object in a simple and effective manner. These and other objects are accomplished by a mounting bracket assembly comprising a stationary bracket to be mounted on a pole or other surface, and an adjustable bracket to be attached to the object to be mounted. The adjustable bracket is then positioned on the stationary bracket to mount the object on the surface or pole. The invention provides the means to mount a product on a pole, pipe, column, or the like, and allow the product to be easily aimed in a particular direction, using separate pole adapters. It can also be used on walls without the pole adapters. It should be resistant to weather, wind, and vibration because it will typically be used outdoors. Stainless steel components are preferable. The bracket assembly is suitable for loudspeakers, lighting, signage, displays, monitors, video cameras, etc. The invention is specifically designed for one person to install a fairly heavy item. The installer never needs to support the weight of the object and handle attachment hardware simultaneously. Competitive solutions require additional parts, more installers, expensive manufacturing methods, multiple adapters, etc. This system uses a minimal amount of inexpensive but robust components, providing both economic and time based efficiency for the installer. The bracket assembly consists of two major components: a stationary bracket and an adjustable bracket. The stationary bracket is attached to the mounting surface, such as a wall, pole, column, etc. The adjustable bracket is attached to the product that requires directional positioning, and this can be done in a more convenient location than at the mount site which may be relatively inaccessible. Tapered springs guide the two brackets together during the initial mating. The adjustable bracket is then rotated into a locked position, and the two mount halves snap together temporarily (without tools or hardware) using integrated hooks and tabs. After this minimal effort, grip on the product can be released to allow for easy completion of the installation process. Two axel screws are inserted loosely through the adjustable bracket into locking threads in the stationary bracket. This forms the hinge, and the assembly is safely secured and ready for adjustment (although tightening of 4 mating screws and a safety tether is required for permanent use). To adjust the adjustable bracket, the tabs are released by compressing the angle adjustment wings on the adjustable bracket, and the product can then be rotated down. The spring causes these tabs to sequentially engage a series of holes so the user can evaluate the dispersion pattern or viewing angle achieved. When the desired position is selected, two screws permanently attach the brackets together and provide additional torque resistance. Finally the two axel screws are tightened to create 4 solid attachment points, and vertical adjustment from 0 to −70 degrees is achieved. For use on poles and the like, the product includes a pole clamp assembly. Two adapter brackets with stepped teeth are attached to the stationary bracket. These adapters are designed for an ideal fit on 1-4″ cylinders, making contact with the cylinder at 4 points each. Larger diameters and irregular shapes can be accommodated, although contact points will likely be reduced to two per adapter. For convenience, a supplied nylon wire tie or other temporary tether is inserted through an opening in the stationary bracket. This can temporarily fasten the stationary bracket with adapters to the pole while clamp components are secured. The clamp is comprised of a length of link chain with a threaded J-hook or hooked rod at each end. These J-hooks pass through aligned slotted openings in the stationary bracket and pole adapters. Wing nuts on the J-hooks provide the means to easily tension the chain adequately without the need for tools, while preventing excessive clamping force. This combination of components fits a wide variety of pole shapes and sizes, produces excellent resistance to rotation, and reduces the likelihood of over tensioning. Additional tension on the clamp components only weakens the system, and wing nuts discourage over-tightening. After installation, the stationary mounting bracket is directly secured to the pole via the chain, hooks, and wing nuts, with the adapters trapped in between. This assembly can be tightened in any position around a pole, providing 360 degrees of horizontal adjustment. This clamp needs only to prevent rotation or slippage and, by nature, chain provides excellent resistance to these forces. A speaker mounting bracket can be attached to the adjustable bracket, so that a loudspeaker can be mounted using the assembly according to the invention. The speaker mounting bracket is securely screwed to the adjustable bracket, and the speaker is mounted on the speaker mounting bracket. The assembly of the speaker, speaker mounting bracket and adjustable bracket can then be easily mounted on the stationary bracket to mount the speaker to a pole or other surface. BRIEF DESCRIPTION OF THE DRAWINGS Other objects and features of the present invention will become apparent from the following detailed description considered in connection with the accompanying drawings. It is to be understood, however, that the drawings are designed as an illustration only and not as a definition of the limits of the invention. In the drawings, wherein similar reference characters denote similar elements throughout the several views: FIG. 1 shows an embodiment of the stationary bracket for use in the assembly according to the invention; FIG. 2 shows an embodiment of the adjustable bracket for use with the stationary bracket of FIG. 1 ; FIG. 3 shows the initial placement of the adjustable bracket of FIG. 2 onto the stationary bracket of FIG. 1 ; FIG. 3 a shows an enlarged detail III of FIG. 3 ; FIG. 4 shows the preliminary mounting position of the adjustable bracket onto the stationary bracket; FIG. 4 a shows enlarged detail IV of FIG. 4 ; FIG. 5 shows the placement of the adjustable bracket into a final mounting position on the stationary bracket; FIG. 5 a shows enlarged detail V of FIG. 5 ; FIG. 6 shows the final mounting position of FIG. 5 , with the screws attached to secure the adjustable bracket to the stationary bracket; FIG. 6 a shows enlarged detail VI of FIG. 6 ; FIG. 7 shows the pole mounting brackets and how they are mounted to the stationary bracket of FIG. 1 ; FIG. 8 shows a front view of the stationary bracket mounted on a pole; FIG. 9 shows a side and rear view of the stationary bracket mounted on a pole; FIG. 10 shows a speaker and a speaker mounting bracket for use with the adjustable bracket of FIG. 2 ; and FIG. 11 shows the entire bracket assembly connected to a speaker and mounted on a pole. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now in detail to the drawings and, in particular, FIG. 1 shows stationary bracket 10 for use in the assembly according to the invention. Stationary bracket 10 has a flat rear panel 11 and two side walls 12 , extending from panel 11 . Side walls 12 have an upper edge with hooks 13 , 14 , and a curved front edge with a series of apertures 15 . Side walls 12 also have a rear aperture 16 . Rear panel 11 has a plurality of mounting holes 17 , for mounting rear panel 11 on a flat surface, and also has slits 18 and supports brackets 19 (shown in FIGS. 3 and 4 ) for securing stationary bracket 10 to a pole, which will be described in detail below. FIG. 2 shows one embodiment of an adjustable bracket 20 for use in the assembly according to the invention. Bracket 20 has a top surface 21 , and side walls 22 with flexible wings 25 below a slit 26 . Tabs 23 and 24 are disposed along the rear and front areas, respectively, of side walls 22 . To connect adjustable bracket 20 to stationary bracket 10 , as shown in FIGS. 3 and 4 , tabs 24 on bracket 20 are placed into engagement with hooks 14 on bracket 10 (also shown in detail in FIG. 3 a ), and bracket 20 is rotated into position, so that tabs 23 on bracket 20 engage hooks 13 (shown in detail in FIG. 4 a ). This creates a temporary mounting position, where bracket 20 is supported by bracket 10 until a final adjustment position can be reached. To reach a final adjustment position, where adjustable bracket 20 is placed at the desired angle with respect to stationary bracket 10 , two axel screws 29 are placed loosely through holes 16 and 28 on each side of brackets 10 , 20 to hold them together. Then, wings 25 are pressed inward until tabs 23 and 24 clear hooks 13 and 14 , respectively, as shown in FIGS. 5 and 5 a . Then, bracket 20 is rotated downward until a desired angle is reached. At this point, wings 25 can be released, which places tab 24 into one of the holes 15 along stationary bracket 10 . If the installer is satisfied with this position, then a further screw 30 is placed into one of holes 15 adjacent to tab 24 , which screw also extends though hole 31 on bracket 20 . Finally all of screws 29 , 30 are tightened to secure bracket 20 to bracket 10 in a final position. Prior to connection of bracket 20 to bracket 10 , the object to be mounted is connected to bracket 20 , and bracket 10 is connected to the mounting surface, such as a wall or a pole. Then, bracket 20 is secured to bracket 10 , to mount the object to the mounting surface, in a simple manner. This way, even large, cumbersome objects can be securely mounted to a pole or a wall by a single installer. As described above, bracket 10 can be mounted to a wall or other flat surface via holes 17 , in any conventional manner. For pole mounting, the arrangement shown in FIGS. 7-9 can be used. As shown in FIG. 7 , pole mounting bracket 19 , which has a vertical section 32 with slots 34 and a horizontal pole-mounting section 33 , can be attached to stationary bracket 10 via screws 36 through holes 17 on bracket 10 , and holes 35 on brackets 19 . The mounting of bracket 10 to a pole 50 is shown in FIGS. 8 and 9 . Bracket 10 , with bracket 19 secured thereto, is placed against a pole 50 , so that horizontal section 33 of bracket 19 abuts pole 50 . Horizontal section 33 has a cutout to create ridged sections 55 , which can grip poles of various sizes, to reduce any slippage between pole 50 and brackets 19 . A strap 40 is then threaded through bracket 10 via slots 38 disposed on side walls 12 just in front of rear panel 11 . Strap 40 keeps bracket 10 in place until further securing measures are taken. Subsequently, hooked securing rods 41 are fed through slots 18 and 34 in brackets 10 , 19 , respectively, and secured on threaded portions 43 with wing nuts 44 . Securing rods 41 each have a hook 42 on its opposite end, which extends along pole 50 . As shown in FIG. 9 , a chain is then hooked on hooks 42 to wrap around pole 50 to further secure bracket 10 to pole 50 . Finally, wing nuts 44 are tightened further to eliminate any slack in chain 52 , thus creating a tight connection between stationary bracket 10 and pole 50 . FIG. 10 shows a possibility for mounting a speaker 60 to adjustable bracket 20 . First, speaker bracket 70 is attached to adjustable bracket 20 by screws 75 through holes 76 in speaker bracket 70 and holes 77 in adjustable bracket 20 . Knobs 63 are attached to speaker 60 on its top and bottom by extending threaded portion 64 of knob 63 through a washer 65 and then loosely screwing knob 63 into holes 62 on the top and bottom of speaker 60 . Thereafter, speaker bracket 70 is attached to speaker 60 by sliding speaker bracket 70 onto threaded portions 64 of knobs 63 via slits 72 until threaded portion 64 resides within aperture 71 . Then, knobs 63 are tightened to secure speaker 60 to speaker bracket 70 , as well as adjustable bracket 20 . Once speaker 60 is connected to adjustable bracket 20 , adjustable bracket 20 can be mounted to stationary bracket 10 , which is already connected to a mounting surface or pole, in the manner discussed above with respect to FIGS. 1-9 , to form a pole-mounted speaker, as shown in FIG. 11 . In this Figure, adjustable bracket 20 has just been placed on stationary bracket 10 , prior to being moved into its final adjustment position and secured with screws, which is done in the manner described with respect to FIGS. 5-6 . Accordingly, while only a single embodiment of the present invention has been shown and described, it is obvious that many changes and modifications may be made thereunto without departing from the spirit and scope of the invention.

A mounting bracket assembly has a stationary bracket to be mounted on a pole or other surface, and an adjustable bracket to be attached to the object to be mounted. The adjustable bracket is then positioned on the stationary bracket to mount the object on the surface or pole. The adjustable bracket is first mounted on the stationary bracket in a preliminary mounting position using integrated hooks and latches, and then can be easily adjusted to a permanent mounting position and secured with screws.

big_patent

FIELD OF THE INVENTION [0001] The present disclosure relates to combustion apparatus, and more particularly, to a burner which may be part of a system including a plurality of interchangeable or modular heat utilizing appliances. BACKGROUND OF THE INVENTION [0002] Fuel burners are used to operate heat utilizing appliances, such as cooking grills, cooktops, food smoking apparatus, space heaters, and pyrolyzers. It is a great convenience to use a solid fuel in such a burner, as solid fuels such as firewood, charcoal briquettes, and others are readily available. However, despite availability of solid fuels, it is desirable to optimize efficiency of a burner, and to limit unburned fuel emissions. [0003] It is also desirable to have modular heat utilizing appliances, so that only one burner need be acquired to operate diverse heat utilizing appliances. [0004] Accordingly, there exists a need for an efficient, clean burning burner capable of being used with diverse heat utilizing appliances. SUMMARY [0005] The disclosed concepts address the above stated situation by providing a an efficient, clean burning burner and a system for removably attaching heat utilizing appliances thereto. [0006] The burner has a combustion chamber enclosed by an outer wall surrounding a fuel holder. Air flows both through the fuel holder to support initial combustion, and also around the fuel holder, to be directed to flame and fumes just above the fuel holder to support secondary combustion. A shroud providing a second wall surrounds the outer wall, thereby establishing a flow path for tertiary combustion air also impinging on the flame and fumes, and also providing an external surface cool enough to avoid burns if casually contacted [0007] The burner has legs holding the combustion chamber well above ground level, and a pivotally coupled ash pan. A perforate food grate is pivotally coupled to the burner, and is movable to a deployed position above the flame, and to a stowed position to the side of the combustion chamber and associated outer walls. Opposite the perforate food grate, a cover is pivotally coupled to the burner, enabling the combustion chamber to be closed to prevent inadvertent ingress of dropped items, inadvertent exposure of the user to heat and exhaust fumes, and to suppress escape of live embers. [0008] The burner has manual couplings for removably coupling modular heat utilizing appliances to the burner, the modular heat utilizing appliances including closed and open cookers, a food smoker, a space heater, and a pyrolyzer. [0009] The nature of the disclosed concepts will become readily apparent upon further review of the following specification and drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0010] Various objects, features, and attendant advantages of the disclosed concepts will become more fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein: [0011] FIG. 1 is a schematic side view of a burner and modular heat utilizing appliances therefor, with some components shown in cross section, according to at least one aspect of the disclosure; [0012] FIG. 2 is a schematic side cross sectional view of the burner of FIG. 1 , according to at least one aspect of the disclosure; [0013] FIG. 3 is a schematic detail side view of optional components located at the lower central portion of FIG. 2 ; [0014] FIG. 4 is a schematic detail side view of the lowermost portion of FIGS. 1 and 2 ; [0015] FIG. 5 is a schematic detail side view of components near the lower portion of FIG. 2 ; [0016] FIG. 6 is a schematic detail side view of an assembly incorporating the component shown in FIG. 2 with one of the modular heat utilizing appliances shown in FIG. 1 , and represented generically in FIG. 6 ; and [0017] FIG. 7 is a schematic side view of components of a pyrolyzer partially shown in FIG. 1 . DETAILED DESCRIPTION OF THE EMBODIMENTS [0018] Referring first to FIG. 1 , according to at least one aspect of the disclosure, there is shown an overview of a system comprising a burner 100 for a heat utilizing appliance and a plurality of interchangeable or modular heat utilizing appliances. Only one of the modular heat utilizing appliances is coupled to burner 100 at any one time. [0019] Referring also to FIG. 2 , there is shown in greater detail a burner 100 for a heat utilizing appliance. Burner 100 comprises a housing 102 and a fuel holder 104 within housing 100 . Housing 102 may comprise a lateral wall 106 surrounding and spaced apart from fuel holder 104 , and a top wall 108 including a constricted exhaust outlet 110 of transverse dimensions 112 (see FIG. 1 ) less than transverse dimensions 114 (see FIG. 1 ) of lateral wall 106 . Constricted exhaust outlet 110 is located above fuel holder 104 . An air inlet opening 116 admits air to fuel holder 104 . Lateral wall 106 and top wall 108 are collectively configured to guide inducted air flowing around fuel holder 104 inwardly from a periphery of housing 102 to join exhaust products flowing upwardly through exhaust outlet 110 when solid fuel 118 is being burned in fuel holder 104 , thereby supporting secondary combustion above fuel holder 104 . [0020] It should be noted at this point that orientational terms such as over and below refer to the subject drawing as viewed by an observer. The drawing figures depict their subject matter in orientations of normal use, which could obviously change with changes in body posture and position. Therefore, orientational terms must be understood to provide semantic basis for purposes of description only, and do not imply that their subject matter can be used only in one position. [0021] Exhaust outlet 110 is constricted in that transverse dimension 111 of exhaust outlet 110 is less than a corresponding transverse dimension 113 of housing 102 . This relationship causes top wall 108 and the immediately overlying portion of outer shroud 128 to channel products of combustion and secondary and tertiary combustion air towards exhaust outlet 110 , so that heat may be concentrated advantageously. [0022] In FIG. 2 , hinges 158 of cover 154 and 164 of grill 160 are fixed to an outer shroud 128 . Accordingly, respective arms 156 and 162 are L-shaped. [0023] In FIGS. 1 and 2 , arrows having outlined heads indicate flow of secondary and tertiary combustion air as combustion air flows by convection through burner 100 . Arrows having solid, filled heads indicates flow of flames and heat produced by combustion of solid fuel 118 . Constricted exhaust outlet 110 may be frustoconical, with the narrowest portion thereof at the center of top wall 108 , as shown, to advantageously concentrate flames and heat at the center of burner 100 . [0024] Fuel holder 104 may comprise a perforate receptacle 120 enabling air inducted from air inlet opening 116 to come into combustion support relation to solid fuel 118 in fuel holder 104 . Fuel holder 104 may comprise an imperforate lateral wall 124 above perforate receptacle 120 . In some implementations (not shown) of burner 100 , imperforate lateral wall 124 may be eliminated. Perforate receptacle 120 may be made from metallic wire welded into a mesh, for example. Other components of burner 100 exposed to heat of combustion may be fabricated from a suitable metallic alloy, such as a suitable steel. [0025] Outer shroud 128 may surround and be spaced apart from upper portion 122 of housing 102 of burner 100 . Outer shroud 128 may be configured to constrain air immediately outside housing 102 to flow by convection radially inwardly to join exhaust products flowing upwardly from exhaust outlet 110 , thereby further supporting secondary combustion and also interposing a thermally insulating barrier between lateral wall 106 of housing 102 and an exterior of burner 100 . Similarly, air flowing upwardly past fuel holder 104 , between fuel holder 104 and lateral wall 106 , cools lateral wall 106 and conserves heat taken therefrom, returning recovered heat to flame and exhaust above exhaust outlet 110 . Introduction of secondary and tertiary combustion air will in most cases cause secondary combustion of unburned and partially burned solid fuel 118 to burn so completely that visible smoke is largely eliminated. This decreases both fuel consumption and also air pollution. [0026] An ash pan 130 may be releasably coupled to burner 100 below fuel holder 104 . Ash pan 130 may comprise a floor 132 and a vertical peripheral wall 134 projecting upwardly from floor 132 . Ash pan 130 thereby forms a sump capable of storing a supply of water 136 to extinguish burning embers (not shown) falling from fuel holder 104 . [0027] Referring specifically to FIG. 3 , air inlet opening 116 may open through vertical peripheral wall 134 of ash pan 130 . To this end, air inlet opening 116 may include a conduit 138 and a damper 140 rotatably supported in conduit 138 . A lever 142 controlling rotational position of damper 140 may be provided for manual throttling of combustion air. [0028] Referring specifically to FIG. 4 , in some implementations of burner 100 , air inlet opening 116 may open through lateral wall 106 of housing 102 . [0029] Referring specifically to FIG. 2 , in some implementations of burner 100 , ash pan 130 is permanently coupled to housing 102 and is movable between a closed position closing a bottom of housing 102 of burner 100 and an open position enabling removal of ashes from ash pan 130 . The closed position is shown in solid lines in FIG. 2 . The open position is shown in broken lines in FIG. 2 . Ash pan 130 may be pivotally coupled to housing 102 by a hinge 144 . Pivotal coupling of ash pan 130 retains the former to housing 102 , and also facilitates draining water 136 from ash pan 130 . [0030] As seen in FIG. 5 , a hook 146 engageable with a multiple position catch 148 may be employed to secure ash pan 130 in any one of several degrees of inclination from the closed position shown in FIG. 2 . Hook 146 may be pivotally mounted to ash pan 130 by a hinge 150 . The degrees of inclination may be utilized to control the amount of combustion air entering the interior of housing 102 . [0031] In summary, burner 100 may comprise an air damper controlling volume of air flow through air inlet opening 116 , the air damper being air damper 140 , or alternatively, ash pan 130 serving as an air damper by virtue of its degree of inclination enabled by multiple position catch 148 . [0032] Referring to FIGS. 1, 2, and 4 , burner 100 may comprise at least one leg 152 coupled to and projecting below burner 100 , whereby burner 100 may be supported above a ground surface (not shown). Where one leg 152 is provided, leg 152 may be driven into the ground sufficiently deep as to prevent burner 100 from falling over. Alternatively, where one leg 152 is provided, leg 152 may include an extension (not shown) projecting beneath the center of gravity of burner 100 . Where the latter alternative is provided, the extension will be sufficiently broad as to stably support burner 100 on the ground. As shown in FIGS. 1, 2, and 4 , a plurality of legs 152 , preferably three legs 152 distributed evenly around housing 102 , may be provided. Leg(s) 152 provide sufficient clearance to enable ash pan 130 to be lowered into the open position shown in broken lines in FIG. 2 without lifting burner 100 from the ground. [0033] As shown in FIG. 2 , burner 100 may further comprise a cover 154 dimensioned and configured to close exhaust outlet 110 of burner 100 . Burner 100 may comprise a hinge 158 pivotally coupling cover 154 to burner 100 by an arm 156 . Cover 154 is solid or imperforate, and prevents inadvertent ingress of objects and a user's hand and fingers (none of these is shown) into combustion chamber 126 . Cover 154 also prevents emission of live embers from combustion chamber 126 . Cover 154 is shown in a stowed position in solid lines, and approaching a deployed position covering and substantially sealing exhaust outlet 110 in broken lines. [0034] Burner 100 may further comprise a grill 160 attachable to housing 102 above exhaust outlet 110 . Grill 160 includes openings (not shown) to enable hot gases to pass from combustion chamber 126 through grill 160 . Burner 100 may further comprise a hinge 164 pivotally coupling grill 160 to housing 102 via an arm 162 supported on a post 166 . Hinge 158 of cover 154 may be similarly supported to housing 102 by a post 168 . Grill 160 is shown in a deployed position in solid lines and in a stowed position by broken lines in FIG. 2 . Cover 154 and grill 160 may be located in diametric opposition on housing 102 , or otherwise located to enable each to be lowered over exhaust outlet 110 without interfering with the other. [0035] Turning now to FIG. 6 , burner 100 may further comprise a coupling for detachably coupling a modular heat utilizing appliance 170 to burner 100 . The coupling may comprise at least one draw latch 172 . Two draw latches 172 located in diametric opposition on outer shroud 128 are depicted. However, one or more than two draw latches 172 could be utilized. Draw latches engage projections 176 in well known fashion. Modular heat utilizing appliance 170 generically represents any one of a number of different types of appliances, any one of which may be coupled to burner 100 at one time. [0036] Again referring to FIG. 1 , burner 100 may further comprise a modular heat utilizing appliance 170 ( FIG. 6 ) further comprising a cooker 174 A further comprising a cooker housing 178 including a bottom section 180 open to exhaust outlet 110 ( FIG. 2 ) of burner 100 , a top section 182 including a vent 184 for venting exhaust, and a support surface 186 inside cooker 174 , for supporting items being cooked (not shown). Support surface 186 may comprise a wire rack for example. Cooker 174 A is a closed cooker wherein food or other items being cooked are substantially enclosed, for example, to achieve higher cooking temperatures. Top section 182 rests on bottom section 180 , and is readily lifted therefrom. [0037] Cooker 174 B presents an open, flat cooking surface 188 . Cooker 174 B may include internal baffles 190 to establish a serpentine flow path for exhaust gases from burner 100 . [0038] Cooker 174 C, intended for smoking, may include a smoking chamber 192 enclosing a wire rack 194 . Smoking chamber 192 is substantially sealed against loss of smoke, apart from vent pipe 194 . [0039] Burner 100 may further comprise a gas-to-gas heat exchanger 198 , whereby environmental air can be heated for space heating. Gas-to-gas heat exchanger 198 may include internal baffles 200 and a vent 202 . Gas-to-gas heat exchanger may transfer heat by convection, radiation, or both. A powered fan (not shown) may be provided to enhance heat transfer to air. [0040] Referring also to FIG. 7 , burner 100 may further comprise a modular heat utilizing appliance further comprising a pyrolyzer 204 including a substantially air-tight heating chamber 206 for pyrolyzing carboniferous materials, such as vegetation (not shown). Heating chamber 206 may include a tightly fitting cap 208 and latches 210 to securely retain cap 208 in place. Heating chamber 206 may be contained within a casing 210 surrounding heating chamber 206 and exposing heating chamber 206 to heat from burner 100 . After transferring heat to heating chamber 206 , products of combustion may be exhausted from vent 212 . [0041] Referring also to FIG. 7 , pyrolyzer 204 may further comprise a condenser 214 for condensing vaporized liquid products of pyrolysis conducted to condenser 214 through a conduit 216 in communication with heating chamber 206 . Condenser 214 is a heat exchanger causing vaporized liquid products of pyrolysis to be recovered as liquids. Liquids of different boiling points may be recovered separately, as represented by two capture conduits 218 , 220 . Gaseous products of pyrolysis may be conducted to a water chamber 222 through a conduit 224 , and bubbled through water 226 . Because heating chamber 206 is sealed, products of pyrolysis will be under sufficient pressure to overcome resistance of water 226 . Gaseous products of pyrolysis may be conducted to a heat exchanger 228 through a conduit 230 , and cooled to a predetermined temperature at which they are deemed safe. Cooled gaseous products of combustion may be collected in a bifurcated conduit 232 for subsequent distribution (conduit 232 B) or use as a fuel in burner 100 (conduit 232 A). Conduits 232 A, 232 B will be understood to include valves (not shown) and other components to achieve functions described herein. [0042] To these ends, pyrolyzer 204 may further comprise conduit 216 , 224 , 230 , 232 , 232 A in fluid communication with substantially air-tight heating chamber 206 and with burner 100 , whereby vaporized products of pyrolysis may be conducted to burner 100 for supplementing solid fuel 118 in fuel holder 104 , or for entirely eliminating use of solid fuel 118 . Also, pyrolyzer 204 may further comprise conduits 216 , 224 , 230 , 232 , 232 B in fluid communication with substantially air-tight heating chamber 206 , an outlet (conduit 232 B) for conducting vaporized products of pyrolysis to an external conduit or storage receptacle (neither shown), and a shutoff valve 234 in the conduit, the shutoff valve enabling control over flow of vaporized products of pyrolysis conducted to the outlet. [0043] Burner 100 may be provided with a fuel feed feature (not shown) to enable renewing the fuel supply during operation, to enable continuous, long term operation. The fuel feed feature may comprise a door in the outermost wall of burner 100 , and optionally, a chute leading from the door to the opening over exhaust outlet 110 . Solid fuel loaded through the door and forced along the chute will drop into fuel holder 104 . [0044] While the present invention has been described in connection with what are considered the most practical exemplary embodiments, it is to be understood that the present embodiments are not to be limited to the disclosed arrangements, but rather the description is intended to cover various arrangements which are included within the spirit and scope of the broadest possible interpretation of the appended claims so as to encompass all modifications and equivalent arrangements which are possible. [0045] It should be understood that the various examples of the apparatus(es) disclosed herein may include any of the components, features, and functionalities of any of the other examples of the apparatus(es) disclosed herein in any feasible combination, and all of such possibilities are intended to be within the spirit and scope of the present disclosure. Many modifications of examples set forth herein will come to mind to one skilled in the art to which the present disclosure pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawings.

A burner for burning fuels and modular heat utilizing appliances therefor. The burner includes a fuel holder, an outer wall surrounding the fuel holder and defining a combustion chamber, and optionally, a second wall surrounding the outer wall. Air is inducted from an inlet which may be an ash pan pivotally coupled to the outer wall at the bottom to open the combustion chamber. Supplementary combustion air is conducted to just above the fuel holder by the outer wall. Additional supplementary combustion air is conducted to just above the fuel holder by the second wall. The burner may include a pivotally mounted cooking grate and a pivotally mounted solid cover for closing the combustion chamber, and supporting legs. Modules individually yet replaceably attachable to the burner include a closed or open cooker, a smoker, a space heater, and a pyrolyzer.

big_patent

BACKGROUND OF THE INVENTION Although rotary internal combustion engines have reached a degree of commercial acceptance, considerable interest is now being devoted to improving fuel economy and durability of such engines. The water cooling system for such an engine is particularly relevant to attaining these two goals. The housing water cooling system, in a rotary engine, functions to lower the temperature of the metal areas exposed to the highest heat input and to minimize temperature differences throughout the housing for preventing destruction. The most severe cooling problem resides in the area where combustion and expansion of the working gases takes place; this area immediately surrounds the spark plugs. The uneven heating can cause housing distortion which, in turn, can prevent proper functioning of the gas and oil sealing elements. The time during which the combustion chamber is cooled by fresh inducted air is fairly short allowing the wall temperature of the combustion chamber to be high and sensitive to changes in load. The maximum temperature of the combustion surface of the trochoid wall is much higher than that of the housing side walls; local overheating can destroy the oil film on the trochoid surface. Sudden acceleration with a cold engine, especially in winter or when auto ignition occurs during high speed driving, exposes the rotor housing and associated trochoid wall to repeated sudden and very large thermal loads. As a result, thermal fatigue or thermal shock cracks can appear about the spark plug holes. In general, cracks occur most frequently on the gas side of the trochoid wall and along the spark plug holes in the axial direction in conformity with high stress concentrations. In extreme cases, cracks can even reach the water jacket. There is a greater need for perfection in design to limit this tendency for thermal distortion which is so highly dependent on the relationship between the cooling system, housing and rotor seals. One particular design aspect that has assumed commercial acceptance, is the use of in-line or dual spark plugs for a single rotor housing. The reason for the dual in-line spark plugs is as follows: In a rotary piston engine with a rotor rotating eccentrically along an inside surface having a trochoid curve, it is ideal for the spark plugs to be installed on the trochoid surface close to the minor axis of the curve, from the standpoint of engine output. However, since the compressed air-fuel mixture also undergoes a rotating motion along with the rotation of the rotor, the rotary engine has a characteristic flame front which advances to the leading side of the rotor and has very little propagation to the trailing side of the rotor. Therefore, the air-fuel mixture disposed in the trailing portion of the rotor combustion pocket is not completely burned. Consequently, the exhaust gas will contain a large amount of unburned gaseous components. To remedy this, another or auxiliary spark plug is installed downstream from the first spark plug and the latter is moved slightly upstream; the auxiliary spark plug is ignited after the first spark plug has been ignited, or in certain cases they may be ignited simultaneously. The necessity for the in-line arrangement is due to the physics of propagation and the desire to have the entire air-fuel mixture totally combusted. The optimum location to do this was thought to be in the center of the peripheral wall whereby the flame front would advance in the direction of movement of the air/fuel mass and proceed laterally across the shortest path toward each of the side walls to combust all of the mixture. Unfortunately, the in-line arrangement of such spark plugs creates a mechanism by which the flow of cooling fluid is considerably disrupted, vapor films collect, and the flow is prevented from carrying away the heat in such a critical area. Spark plugs for an internal combustion engine, such as a rotary, are typically installed into the threaded ports of the spark plug bosses. Since a rotary engine has a relatively thin trochoid wall, cylindrically shaped bosses for the spark plugs must be cast and extend into the engines water jacket passageway which is adjacent to such wall. The interruption or interference of such bosses within the water jacket passageway has a benefit in that the bosses themselves are cooled to carry away heat but the total heat for the entire hot spot area is detrimentally affected; the cooling flow is extremely sensitive to hindrances preventing heat extraction. Each boss in a four-cylinder reciprocating engine will be affected by generally 1/4 of the total heat of combustion for the engine. This is not a severe problem in connection with reciprocating type internal combustion engines since the spark plug bosses are well separated in the cylinder heatt water jacket and, in fact, can be considered as one spark plug per cylinder. However, in contradistinction, the spark plug bosses in a rotary engine are cast in close proximity to the circumference of each rotor housing, do not have special coolant transfer ports for improved cooling, and are generally affected by 1/2 of the total heat of combustion for a two rotor engine (for a one rotor engine, the bosses would be effective by the total undivided heat of combustion). As the rotary design has developed, spark plugs have been fitted into the threaded ports which open onto the most critically cooled zone of the trochoid combustion surface - a major hot spot where thermally induced structural failures are more likely to occur. If the cooling flow cannot carry away the heat in a uniform manner, the exact amount of excess heat in such hot spot will cause detrimental results. The in-line arrangement of spark plug bosses in such water passageway contributes, in a significant manner, to preventing adequate heat extraction. Particularly in the vertically upward flow of the cooling circuit, where in-line spark plugs are typically placed, the up-stream plug boss creates a flow shadow effect upon the down-stream plug boss preventing a controlled or well ordered flow regime (absence of swirling eddies which deteriorate heat transfer). Boiling at the plugs results in a vapor stream which widens the uncontrolled flow zone and aggravates the heat transfer problem. SUMMARY OF THE INVENTION A primary object of this invention is to provide an ignition and cooling system combination which is effective to maintain an efficient level of combustion while improving cooling characteristics to reduce the possibility of structural failure of the engine's housing. Another object of this invention is to provide a housing structure which facilitates circumferential cooling flow in the rotor housing while permitting the intrusion of spark plug bosses therethrough, the housing being structured to minimize thermal distortion, particularly in the zone surrounding said spark plug bosses. Still another object of this invention is to provide a housing for a rotary internal combustion engine having a peripheral cooling circuit defined so that there are separate flow paths for release of boiling vapor from a plurality of spark plug bosses interrupting such circuit. Yet still another object of this invention is to provide a housing structure for a rotary internal combustion engine which employs circumferential cooling having a vertical flow moving past bosses therein which are an integral part of said structure, the structure being made to increase the heat transfer coefficient of said cooling circuit at the spark plug boss zone by at least 20 % over prior art capabilities. Structural features pursuant to the above objects comprise the use of (a) plug bosses interposed in a circumferential cooling flow passageway of the rotor housing, and staggered with respect to the direction of flow, the arrangement of the plurality of spark plugs and accompanying bosses are offset but symmetrically oppositely oriented about a centerplane of said flow and skewed with respect thereto so that the staggered arrangement promotes relatively close in-line arrangement of the spark plug terminals, (b) the incorporation of a predetermined and limited offset from a line extending between the spark plug terminals so as not to detrimentally affect propagation of the combustion flame while yet allowing for said staggered boss configuration, and (c) the use of flow diverters or flow controllers between the spark plug bosses to insure a controlled flow regime between the bosses and for strengthening the housing structure. SUMMARY OF THE DRAWINGS FIGS. 1 and 2 represent schematic illustrations of spark plug boss arrangements for the inventive mode and the prior art mode respectively; FIG. 3 is a sectional elevational view of one rotor housing and rotor for a multi-rotor rotary internal combustion engine embodying the principles of this invention; FIG. 4 is a view taken substantially along line 4--4 of FIG. 3; FIG. 5 is a side elevational view of the fragmentary structure of FIG. 4; and FIG. 6 is an end elevational view taken along line 6--6 of the fragmentary structure of FIG. 4. DETAILED DESCRIPTION Spark plugs for any type of internal combustion engine are typically installed into threaded openings within spark plug bosses. The cylindrically shaped bosses are cast into the engine water jacket passageway to prevent cracking of the support structure due to thermal distortion. Coolant flow velocities are directed over these critically cooled surfaces of the bosses to lower the metal temperatures and, ideally, to prevent excessive temperature variation across the walls defining said passageway (i.e., hot spots which induce thermal distortion and attendant failure of the housing structure). Turning to FIG. 2, there is schematically illustrated in plan view, an arrangement characterized as "in-line" for bosses 8 and 9 with respect to a centerplane 54 extending through a water jacket passage of a typical prior art rotor housing. Cooling flow is aggravated during boiling heat transfer at high engine power settings; vapor released from the upstream boss surfaces induce further variations in the coolant velocity distribution across the downstream boss laying in the flow shadow of the upstream boss for the in-line arrangement. In FIG. 1 there is, schematically shown, bosses which are staggered with respect to the centerplane 54 of flow of the coolant in the water jacket passage for a rotary engine employing the principles of this invention. The construction of FIG. 2 provides superior coolant performance about the circumference of each spark plug boss when compared to closely spaced "in-line" bosses, the latter preventing high speed coolant flow between the bosses. The distribution of coolant velocities around the staggered spark plug boss surface is improved since flow around each boss is less dependent on the presence of the other boss in the water jacket passageway. The vapor released from the upstream boss is carried away from the coolant stream impinging on the downstream boss. This reduces locally high thermal conditions by improving the distribution of coolant velocities around the boss surface and hence the engine water jacket by providing separate paths for vapor release during boiling heat transfer. In some particularity, a preferred embodiment is shown in FIGS. 3-6. The rotary engine of FIG. 3, comprises a housing A, a rotor B, an induction system or means C, an ignition system D, means E which is effective to define a cooling passageway, and boss means F useful in containing the ignition means within the water passageway. The housing A has an internal wall 10 which is epitrochoidally shaped to delimit a chamber in cooperation with side housings disposed on opposite sides of housing A (rotor housing). The epitrochoid chamber has a minor axis 11 and a major axis 12. The rotor C is generally triangularly shaped with three outer arcuate faces 13; apex seals 14 are disposed at the apices where the faces 13 intersect. The seals cooperate in defining with the rotor and housing a plurality of variable volume combustion chambers 15, 16 and 17. The rotor is mounted for planetary movement within the trochoidally limited chamber bounded by an internal epitrochoid wall 10 and has an eccentric surface 18 which is in contact with an eccentric shaft 19. A combustible mixture is inducted through system C; the system has a carburetor 22 effective to inject said mixture through intake passage 20 leading to the trochoid chamber. An exhaust passage 21 withdraws the exhaust gases upon completion of the combustion cycle. The ignition means D utilizes a plurality of spark plugs, here shown two in number, 25 and 26, which are arranged at stations on opposite sides of the minor axis 11. The spark plugs may be of the conventional flat-gap type and each has a threaded portion 28 received in a threaded portion of a bore in said boss means F. The spark plugs have terminal portions 27 and 29 respectively with appropriate lead-in electrical wires 30 for carrying a pulse of energy to excite sparks in a precise sequence. The terminals 27 and 29 are almost coincident with the trochoid surface 10 and therefore can be represented in our discussion by substantially a point station. Means E, defining the cooling passage, extends from an entrance at 31 into the housing (at about a 7 o'clock position) to an exiting station 32 (at a 1 o'clock position). The housing means E comprises a wall 34 separating the trochoid chamber 10 from the cooling passage E and has a predetermined thickness which is relatively thin. The passage may have one or more rather elongated ribs 33 for guiding or structurally reinforcing the housing passage. The flow proceeds along a path which has a centerline 46 and has a substantial segment thereof which is rising vertically along the side of the rotor housing A. The boss means F comprises two cylindrically shaped and cast bosses 41 and 40 which extend across the passageway at a location adjacent the vertically rising section of said flow. The centerline, 44 and 45 respectively, of each boss is skewed with respect to a centerplane 54 dividing the passageway longitudinally. The bosses have an arrangement such that the terminal of each spark plug will project onto a point on the trochoid wall 10 preferably offset a distance 60 (from the centerline 61 of said trochoid wall (see FIG. 1). The combined offset distances are less than the diameter of either of said bosses. The bosses are arranged so that, looking at them along the passageway, they show frontal or upstream portions 40a and 41a which are substantially non-overlapping whereby fluid flow of a high velocity may scavenge such surfaces and prevent the collection of vapor generated at such hot surfaces. Vapor generation tends to collect and develop a vapor binding film 50 along the upstream side of each boss in an "in-line" situation (see FIG. 2). Ideally, the positioning of the terminals 27 and 29 of each spark plug for this invention approach an in-line arrangement on the trochoid surface 10 (gas side of wall 34), while the bosses are arranged to effect a very definite and noticeable offset arrangement in the passage E. The bosses are packaged in the housing in such a manner that the boss centerlines 44 and 45 will each form an angle 70 with respect to the plane 54 dividing the coolant passage longitudinally and an angle 72 with respect to a plane 55 dividing the coolant passage transversely. The range for such angles is as follows: Angle 70 is preferably about 25°-65° and angle 72 is preferably about 15°-55°, but operably can be reduced to 0° for each angle. The cylindrical trunk of each boss has the terminals 27 and 29 spaced apart a longitudinal distance 51 which is typically less than 12 diameters of each boss; the distance 51 is somewhat limited by the pocket 73 design for the rotor. However, irrespective of the pocket design, if the boss diameter is relatively small so that side wall effects on the flow about the bosses can be ignored, then this invention is important for spacings between bosses up to 50 boss diameters. In applications where the boss diameter is relatively large with respect to the width of the cooling passage, side wall effects will be present and the invention will be important for longitudinal spacings between bosses of up to 12 diameters. As a result of the staggered configuration of the spark plug bosses, high velocity flow therethrough is controlled and devoid of uncontrolled swirling eddies so that a high heat transfer coefficient can be maintained at the sensitive spark plug boss surfaces. Geometrically, the flow is split into several paths as it swings to different sides of the upstream spark plug boss 40 and thence at portion divides about the downstream boss 41. Accordingly, vapor released from either one of the boiling surfaces of the spark plug bosses enters the swinging controlled split paths. Tests were undertaken to visually compare the flow regime of a water model passageway simulating the passage plug bosses. Two models are undertaken, one with staggered spark plug bosses and one with "in-line" spark plug bosses. Small neutral density plastic particles, entrained in the water flow stream, were used to trace the contours of the coolant flow path. In addition, electrolysis of the water was employed to produce hydrogen gas (bubbles smaller than the vapor bubbles typically encountered in the rotary engine). The hydrogen gas was found to collect in rather large crescent shaped zones 50 on the upstream side or frontal face 40a and and 41a of the in-line bosses, such as shown in FIG. 2. However, with the staggered spark plug configuration, high speed controlled flow sweeps these vapor particles clean from such upstream sides or frontal faces and it has been determined that the heat transfer coefficient between the flow and bosses is increased by as much as 44% for the model study. To relate this to an actual engine housing, the change in heat transfer rate was calculated utilizing a maximum flow velocity of about 4.1 feet per second and volume flow rate of about .033 cubic feet per second. The temperature of the coolant flow at the wall was measured to be approximately 320°F and at the coolant flow centerline at about 225°F, thereby rendering an average coolant flow temperature of about 270°F; the minimum projected area of the passageway about the zone adjacent the spark plug bosses was 1.17 square inches. Calculation of the Reynolds number for the flow determined it to be about 1.2 × 10 5 (a non-dimensional number) which indicated that the flow was in a controlled turbulent condition. The heat transfer coefficient, calculated for the "in-line" arrangement, was about 1800 Btu/Hr/Ft 2 /°F. This was in sharp contrast with the heat transfer coefficient calculated for the staggered arrangement which was about 2600 Btu/Hr/Ft 2 /°F. [The diameter of the spark plug boss as assumed to be about .85 inches with the height of each boss being approximately .80 inches]. The temperature gradiant across the width of the gas side (surface 10) of the wall 34, rather than being a variable distribution with the highest temperature at the centerline 61 of surface 10, as for an in-line arrangement, is now found to be more uniform and flat but less symmetrical. The amount of offset 60 of a spark plug terminal (viewed as the intersection of axes 47 and 48 for each boss in FIG. 1) is important. The offset 60 is a dimension that should be viewed with reference to the centerline 61 of the surface 10; it must preferably be less than a radius of a boss to achieve the benefits of this invention.

A rotary internal combustion engine is disclosed having circumferential type cooling circuit for the rotor housing and a plurality of spark plugs extending through the trochoid wall of the rotor housing at a vertically rising zone of said circuit. The plugs are contained by bosses extending through the coolant flow passage; the bosses are arranged to stagger the up-stream sides of said bosses with respect to controlled flow of coolant thereabout, thereby increasing flow control, increasing heat transfer, and preventing a collection of vapor which may act as an insulation film hindering heat transfer between said bosses and coolant flow. The centerline of said bosses are preferably skewed with respect to both a plane bisecting the flow longitudinally and a plane bisecting the flow transversely, whereby the spark terminals of said plugs may be maintained within narrow offset limits on opposite sides of a centerline of the gas side of said trochoid wall.

big_patent

[0001] The present invention relates to turbines, and, in particular, to a method of minimizing flow disturbance caused by the closing and reopening of turbine control valves during periodic operational testing, and specifically, to using control valve positions as feedback to minimize such flow disturbance. BACKGROUND OF THE INVENTION [0002] Required operating procedure for turbines includes periodic operational testing (closing and reopening) of parallel inlet flow control valves used in turbines. The testing is done to confirm operability of turbine safety mechanisms. One problem with such testing is changes in the turbine steam boiler pressure or changes in turbine power as a result of the closing and reopening of the turbine control valves during the periodic operational test. Steam boiler pressure changes or turbine power changes must be minimized during turbine control valve operational safety test stroking. When present, the turbine inlet pressure regulation or turbine power feedback must not be affected or modified to achieve the compensation. [0003] One pre-existing method to minimize inlet pressure excursions uses turbine inlet pressure in a proportional regulator. The inlet pressure regulator design is defined and required by the steam boiler design and, thus, cannot be modified. Other methods that have been used to compensate for turbine power disturbances caused by flow changes that occur during operational testing of inlet control valves are the use of electrical power feedback in a proportional plus integral regulator, or the use of turbine-stage pressure feedback in a proportional regulator. Neither of these methods may be applied to the inlet pressure problem because they both allow inlet pressure to change. Some of these methods also involve the monitoring of additional process parameters. BRIEF DESCRIPTION OF THE INVENTION [0004] The present invention is a method of minimizing steam boiler pressure changes or turbine power changes during turbine control valve operational safety test stroking. The method of the present invention uses control valve positions as feedback to minimize flow disturbance caused by the closing and reopening of a turbine control valve during periodic operational testing. By maintaining the total mass flow through several parallel turbine inlet flow control valves constant, the steam generator pressure is maintained constant, and the inlet pressure regulator is unaffected during inlet control valve testing. Maintaining the total mass flow through several parallel turbine inlet control valves constant minimizes turbine power changes during inlet control valve testing. The position (valve stem lift or stroke) of the individual parallel valves is already present because it is used for closed-loop control of the inlet control valve positions. The valve position is sufficient, and results in improved performance, for the purpose of maintaining constant total flow when the method described herein is utilized. The monitoring of the available or additional process parameters for the purpose of reducing flow disturbance during inlet control valve testing, is not needed. [0005] The flow is determined as a function of control valve position, i.e., valve stem lift. The flow change due to closure of one of the several parallel flow paths during valve testing, results in a change to the system that is controlling pressure from N valves to N- 1 valves. The flow characteristic for each valve of the system with N valves, and for the system with N- 1 valves, is determined during the turbine design process. The flow characteristics thus determined are based on total flow and individual valve stem lift. For any given valve not under test, the difference in the flow-lift characteristic between the N and N- 1 condition is known. This difference is applied to the total flow demand to each of the N- 1 valves on the basis of the total N valve demand derived from the position of the valve under test. BRIEF DESCRIPTION OF THE DRAWINGS [0006] FIG. 1 is a graph showing the total flow characteristic for a system when controlling with N valves and when controlling with N- 1 valves for various valve lift values. The graph also shows the flow difference between the N and the N- 1 condition as a function of valve lift. [0007] FIG. 2 is a block diagram of a control circuit for controlling the flow through the input control valves of a turbine showing the interfacing of such circuit with the flow control circuit for one valve of a total of N valves present in the turbine. [0008] FIG. 3 is a block diagram of an exemplary flow control circuit with control valve test compensation for one valve of a total of N valves present in a turbine. [0009] FIG. 4 is a graph of the control valve test flow compensation showing additional flow demand required for three valves to equal mass flow through four valves. [0010] FIG. 5 is a graph of a control valve test with an inlet pressure regulator and without the flow compensation function. [0011] FIG. 6 is a graph of a control valve test with an inlet pressure regulator and with the flow compensation function. DETAILED DESCRIPTION OF THE INVENTION [0012] The present invention is a method of using control valve position as feedback into a compensation function to minimize flow disturbance caused by the closing and reopening of a turbine control valve during periodic operational testing. According to the method of the present invention, total mass flow for N parallel flow valves is calculated as a function of control valve position (valve stem lift). The flow change due to closure of one of the N parallel flow valves during valve tests, results in change of the system that is controlling pressure from N valves, to N- 1 valves. The flow characteristic for each valve of the system with N valves, and for the system with N- 1 valves, is determined during design. The flow characteristics are based on total flow (valve) demand. For any given valve not under test, the flow difference characteristic between the N and the N- 1 condition is known. [0013] FIG. 1 is a graph 10 showing the difference in flow characteristics between N and N- 1 turbine flow control valves. The bottom horizontal axis of graph 10 represents flow in pounds mass per hour (lbm/hr). The left vertical axis represents stem lift (valve opening) in inches, while the right vertical axis represents the percentage (position-%) of a valve opening with respect to the maximum opening of which the valve is capable of providing. The top horizontal axis of graph 10 represents the percentage of power of a steam turbine taking steam from a nuclear power source (Rx power-%). [0014] Curve 12 shows the total level of flow (lbm/hr) versus stem lift (inches), for a total of four turbine control valves. Curve 14 shows the total level of flow versus stem lift for three of the four turbine control valves, where one of the control valves has been closed for test purposes. Curve 16 represents the actual difference between the total mass flow for four turbine control valves and the total mass flow for three of the turbine control valves where one of the control valves has been closed. Thus, for example, if each of the control valves in a four-valve set had a stem lift of 1″, the corresponding flow for all four valves being open would be approximately 5.5E+06 lbm/hr. Conversely, if one of the four control valves were closed, the remaining three valves would produce a corresponding flow of 4.0E+06 lbm/hr where each of the three valves had a stem lift of 1″. This difference is reflected in graph 16 where a stem lift of 1″ on graph 16 corresponds to a flow difference of approximately 1.5E+06 lbm/hr. [0015] Curve 18 represents a “smoothing out” of curve 16 to provide a more appropriate curve to control flow change of the three control valves remaining open to minimize flow disturbance of the fourth valve is closed and then reopened. Thus, for example, if the flow through four valves were 8.0E+06 lbm/hr, curve 12 in graph 10 indicates that each of the valves has a stem lift of approximately 1.4″. If one of the valves is then closed for test purposes, to compensate for the loss of flow through the closed valve, the remaining three valves would require additional lift of approximately 0.6″ per valve to maintain a flow of 8.0E+6 lbm/hr. Curve 18 can be obtained on a visual approximation basis or by using a mathematical approach, such as regression analysis. [0016] FIG. 2 is a block diagram 20 generally showing the manner in which the mass flow through each of several parallel turbine inlet control valves is controlled. As shown in FIG. 2 , a turbine 22 includes several process sensors relating to the operation of the turbine. These sensors include a load sensor 24 , a speed sensor 26 and a pressure sensor 30 , the latter of which is connected to a control valve 28 controlling the flow of process fluid to turbine 22 . The outputs of sensors 24 , 26 and 30 are provided as inputs 25 , 27 and 31 , respectively, to a load controller 38 , a speed controller 36 and a pressure controller 32 used to control the operation of turbine 22 . The outputs 34 , 35 and 40 , respectively, of pressure controller 32 , speed controller 36 and load controller 38 , in combination, constitute turbine 22 's processor controller's flow demand. Outputs 34 , 35 and 40 are fed into a selector 42 , and in combination, produce an output 44 which is the selected total flow demand used by the process controller to control the flow through the control valves providing mass flow into the inlet of turbine 22 . Output 44 of selector 42 is referred to as “TCV Reference”, which is a signal that effectively establishes the total flow demand for the valves to produce. In normal operation, the TCV Reference signal is fed into a test control circuit 48 which includes the means to convert the TCV reference into the required valve position and generates an output 49 that establishes Valve Position Demand. Output 49 is received by a valve servo position loop 47 which provides closed-loop position control of the lift of valve 28 . [0017] To minimize steam boiler pressure changes or turbine power changes during turbine control valve operational safety testing, the present invention uses a test compensation circuit 50 . This compensation circuit uses control valve positions as feedback and compensates by adjusting the flow through parallel control valves to minimize flow disturbance caused by the closure and reopening of turbine control valve 28 during testing. Test compensation circuit 50 is shown in greater detail in FIG. 3 . According to the present invention, the test compensation circuit 50 would be reproduced along with test control circuit 48 and valve servo position loop 47 for each valve of several parallel turbine inlet control valves used to control the mass flow through turbine 22 . In this regard, output 44 of selector 42 would be provided as signals 41 , 43 and 45 to control valves 2 , 3 and N, respectively, as shown in FIG. 2 . [0018] FIG. 3 is a more detailed block diagram of the test control circuit 48 commonly used to control mass flow through parallel turbine inlet control valves. Test compensation circuit 50 is also shown in more detail in FIG. 3 . In particular, circuits 50 A and 50 B shown in FIG. 3 together constitute test compensation circuit 50 shown in FIG. 2 . [0019] Referring to block diagram 50 A in FIG. 3 , signal 46 , TCV Reference, is input to a test compensation array 52 and a summing circuit 59 . Signal, TCV Reference, is indicative of the mass flow demand for all of the parallel inlet control valves to achieve a desired level of total mass flow through turbine 22 . Test compensation array 52 is essentially a “look up table” that provides, for the mass flow difference demanded by TCV Reference, for the three input control valves not being tested, where a fourth one of the control valves is being closed for testing. As noted above, the flow compensation required for a given TCV reference comes from curves 16 and 18 shown in FIG. 1 , which show the difference in total mass flow for three turbine control valves versus four turbine control valves for different values of valve stem lift. [0020] FIG. 4 is a graph effectively representing the function performed by Test Comp Array 52 . The compensation array, Test Comp Array 52 , is based on the mass flow being demanded (“TCV Reference”). This then skews the graph 18 shown in FIG. 1 to look like curve 74 in graph 75 of FIG. 4 . The bottom horizontal axis of graph 75 represents mass flow demanded (“TCV Reference” in percentage) that is input to Test Comp Array 52 . The left vertical axis represents flow compensation (in percentage) that is output from Test Comp Array 52 . [0021] The output of Test Comp Array 52 is fed into a sample and hold circuit 54 , which receives a signal 55 identified as “CVx Test State”. The signal, “CVx Test State”, is a logic “True/False” signal generated by the activation of a test switch (not shown), which indicates whether the particular input valve controlled by circuit 48 shown in FIG. 3 (here, valve # 1 ) is in test mode. If it is, “False” (meaning that valve # 1 is not being tested) signal “CVx Test State” enables sample and hold circuit 54 to pass the output of Test Comp Array 52 into a multiplier circuit 56 . Sample and hold circuit 54 provides the flow compensation for the three input control valves not under test (which include valve # 1 ) with respect to the mass flow demanded by the TCV Reference signal. [0022] Also inputted into multiplier circuit 56 is a second signal 70 , identified as “CVx Comp Ref”, which is generated by the circuit of block diagram 50 B. “CVx Comp Ref” is the amount of flow compensation needed at a given TCV Reference for the for the three valves not under test. [0023] Referring now to FIG. 50B , an input signal 60 , identified as “Position From CV Servo Regulator For CVm”, is input into a Lift Flow Array 62 . The signal “Position From CV Servo Regulator For CVm” is dynamic signal that indicates the lift position of the valve (here, valve # 1 ) being controlled by circuit 48 shown in FIG. 3 and the valve servo position loop ( 47 in FIG. 2 ). Lift Flow Array 62 is also essentially a “look up table” that provides, for the stem lift of valve # 1 , a translation to a total flow demand value for use by the three input control valves not being tested (which include valve # 1 ), when a fourth one of the control valves is being closed for testing. As noted above, the translation to total flow demand value comes from curve 12 shown in FIG. 1 , which show the total mass flow for four turbine control valves for different values of valve stem lift. [0024] Sample and Hold Circuit 64 receives a signal 71 identified as “CVm Test Select”, which is the logic “True/False” signal generated by the activation of the test switch (not shown), which selects the particular input valve controlled by test control circuit 48 shown in FIG. 3 (here, valve # 1 ) for testing. If “CVm Test Select” is “False”, it enables Sample and Hold Circuit 64 to pass the flow demand value from Lift Flow Array 62 to a Divider Circuit 66 . When “CVm Test Select is “True”, the flow demand value from Lift Flow Array 62 is held and passed to Divider Circuit 66 . Lift Flow Array Circuit 62 also provides Divider Circuit 66 with a varying flow demand signal for the other three input control valves not under test, as the stem lift of such tested valve, such as valve # 1 , varies. [0025] The denominator “B” of the divider circuit 66 is the flow demand value from Lift Flow Array 62 . This value remains the same during the test closing of a given valve. The numerator “A” of the divider circuit 66 is the varying flow demand value from Lift Flow Array 62 that changes as the tested valve is closed and reopened. The output of the divider circuit 66 is a fraction that starts at 1 (meaning no compensation) and gets progressively closer to 0 (meaning 100% compensation) as the tested valve is closed. [0026] The output of the divider circuit 66 is then fed into a summing circuit 68 which also receives an input signal identified as “K One”, a reference signal with a constant value of “1”. The output from Divider Circuit 66 (initially 1 for no compensation) is subtracted in Sum Circuit 68 from the fixed constant of “1” constituting signal “K One”. For a given valve being tested, this subtraction produces an output of “0” that is fed into Multiplier Circuit 56 of the valves not being tested, as the signal “CVx Comp Ref”. Signal “CVx Comp Ref” begins at 0, and, as the tested valve is closed, the numerator “A” in Divider Circuit 66 changes as the varying value of the lift position of the tested valve changes as the tested valve is closed and then reopened. As the output of Divider Circuit 66 gets smaller and smaller as the tested valve is closed, the output of Sum Circuit 66 increases from 0 to 1. As the tested valve is reopened, the output of Sum Circuit 66 decreases from 1 to 0. The output of summing circuit 68 is output signal 70 , “CVm Comp Reference”, which, as noted above, is input into multiplier circuit 56 . [0027] As also noted above, CVx Comp Ref” is an indication of the amount of flow compensation needed for the for the three valves not under test. Thus, by way of example, if valve # 4 is being tested, and each of valve #s 1 , 2 , and 3 need to be opened from 1-inch to 1½ inches to compensate for the mass flow lost by the full closing of valve # 4 , the additional ½-inch″ of lift is the result of the flow compensation value multiplied by a compensation factor that's going to move the lift for valves 1 , 2 and 3 from 1″ to 1½″ as valve # 4 closes. Thus, as valve # 4 is closed, the flow compensation for each of valves 1 , 2 , and 3 would be multiplied by “CVx Comp Ref”, which is a changing signal starting out initially at 0 and increasing to 1 or 100% as valve # 4 is fully closed. [0028] The output of multiplier circuit 56 is fed into a Select Circuit 58 , which also receives a second signal “K Zero”, a reference signal with a constant value of “0”, and a third signal from valve test control circuit 48 that determines whether reference signal “K Zero” or the output of multiplier circuit 56 is fed into Sum Circuit 59 . In Sum Circuit 59 , either the “0” output of Select Circuit 58 or the valve stem lift compensation signal output of Select Circuit 58 is summed with the signal “TCV Reference” and fed into a Flow Lift Array 73 that determines the valve lift of valve # 1 , as controlled by test control circuit 48 . The logic of the test control circuit is such that the Select Circuit 58 will output the value of multiplier circuit 56 only when a valve, other than itself, is being tested. [0029] To test the method and system of the present invention, a turbine system to be controlled was mathematically modeled, thermodynamically accurate, and simulated in real time. The model system consisted of source and sink with four parallel control valves individually controlling flow through four nozzles. The simulated system was connected to the embodiment of the control system of the present invention described above. The control system contained the algorithms for compensation of flow during valve testing as described above. For comparison, the control system was configured to include flow compensation and not use flow compensation. The overall control strategy requires control of pressure ahead of the valves using a proportional regulator. The use of the control valve test compensating control of the present invention reduced the pressure excursion of the turbine inlet main (throttle) steam pressure by 95%, as shown in FIGS. 5 and 6 , respectively. FIG. 5 is a graph 80 that shows the results of a control valve operative test without the flow compensation of the present invention, while FIG. 6 is a graph 82 that shows the results of a control valve test with the flow compensation of the present invention. In both tests, valve # 3 was the valve closed for test purposes. The position of valve # 3 is shown as curve 84 in both FIGS. 5 and 6 , while the pressure change in the steam pressure of the system when valve # 3 is originally open, closed, and then reopened, is shown as curve 86 . The position of each of valve # 1 , 2 and 4 is shown as curves 81 , 83 and 85 , respectively, in both FIGS. 5 and 6 . [0030] While the invention has been described in connection with what is presently considered to be the preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

The present invention is a method of minimizing steam boiler pressure changes or turbine power changes during turbine control valve operational safety test stroking. The method of the present invention uses control valve positions as feedback into a compensation algorithm to minimize flow disturbance caused by the closing and reopening of a turbine control valve during periodic operational testing. By maintaining the total mass flow through several parallel turbine inlet control valves constant, the steam generator pressure is maintained constant, and the inlet pressure regulator is unaffected during inlet control valve testing. Maintaining the total mass flow through several parallel turbine inlet control valves constant also minimizes turbine power changes during inlet control valve testing. In addition, the monitoring of additional process parameters is not needed. The position (valve stem lift) of the individual parallel valves is used for closed loop control of inlet valve position, and is sufficient for the purpose of maintaining constant flow.

big_patent

BACKGROUND OF THE INVENTION This invention relates in general to mixing valves for combining fluids from two separate sources into one mixture, and more specifically to a mixing valve for an aircraft cleaning apparatus having two inlets A and B, and one outlet, wherein the outlet mixture comprises a solution ranging from 0% inlet A fluid, 100% inlet B fluid to 100% inlet A fluid, 0% inlet B fluid. Pressurized cleaning apparatuses are well known and comprise many different: forms. For example, a garden hose connected to a typical household faucet may be used to provide a source of pressurized "tap" water for a variety of cleaning needs. In order applications, such as a public car wash, a mechanism is provided for selecting pressurized water only, or a predetermined mixture of pressurized water and a concentrate such as soap or wax. A smaller vehicle cleaning system which operates on this principal is disclosed in U.S. Pat. No. 4,967,960. Likewise, a drain cleaning apparatus operating in this manner is disclosed in U.S. Pat. No. 4,773,113. A Larger system employing this principal for cleaning commercial aircraft is disclosed in U.S. Pat. No. 5,161,753. In many of the cleaning apparatus previously described, some type of valve apparatus is employed to allow one fluid to intermix with another fluid, thereby providing a solution of predetermined concentration. Such a system using an aspirator-transfer valve is shown in U.S. Pat. No. 4,726,526. Other valve configurations, such as that shown in U.S. Pat. No. 5,069,245, permit the mixing together of two liquids according to plurality of predetermined proportion settings. In the commercial airline industry, aircraft are typically cleaned extensively on a yearly basis by "teams" of airline employees. Such a task usually involves the use of a variety of cleaning agents and bulky cleaning machinery. It would therefore be desirable provide a stand-alone cleaning apparatus that would allow multiple users to accomplish specific cleaning task without disrupting the other members of the team. It would further be desirable to provide each user with complete control over the strength of the particular cleaning solution being used. Such a system must therefore be capable of providing a constant pressure cleaning solution to each user wherein the cleaning agent to water ratio is continuously adjustable. SUMMARY OF THE INVENTION The present invent:ion meets the aforementioned objectives by providing a mixing valve having a valve body, a first inlet passage defined in the body for receiving a first fluid at a first predetermined pressure, a second inlet passage also defined in the body for receiving a second fluid at a second predetermined pressure, an outlet passage defined in the body for providing a proportional mixture of the two fluids, and a valve means disposed within the body for directing the two fluids toward the outlet passage. The valve means is adjustable to permit the mixture to range, analog fashion, between a proportion of about 0% first fluid, 100% second fluid to about 100% second fluid, 0% first fluid. These and other objects of the present invention will become more apparent from the following description of the preferred embodiment. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded view of a spool valve and its various valve components, in accordance with the present invention. FIG. 1a is a left side plan view of a valve body in accordance with the present invention, showing internal fluid paths in phantom. FIG. 2 is a perspective view of a flow restricting device for use in the valve system of the present invention. FIG. 3 is a rear cross-sectional view, along lines 3--3 of the valve body shown in FIG. 1a, wherein a mechanism for restraining translational movement of a spool valve disposed within the valve body is shown. FIG. 4 is a bottom plan view of the valve body shown in FIG. 1a. FIG. 5 is a cross-sectional view of the valve body of FIG. 1a with the valve assembly of FIG. 1 disposed therein. DESCRIPTION OF THE PREFERRED EMBODIMENT For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates. Referring to FIGS. 1 and 1a, the various components of valve system 5 are shown in accordance with the present invention. Valve body 10 defines a bore 12 therethrough having a predetermined bore diameter. One end of bore 12 terminates at the top surface of body 10 and the other end terminates at one end of a second bore 14 having a bore diameter larger than that of bore 12. The opposite end of bore 14 terminates at the bottom surface of body 10. Body 10 further de:fines a first inlet passage 28 having a threaded portion 30 at one end for connecting to a source of soap solution (not shown). In one embodiment, soap solution is supplied at between approximately 1200 and 1400 psi. At the opposite end of the first inlet passage 28 body 10 defines a second threaded passage 18 for receiving a complementarily threaded flow restricting device 20 (FIG. 3). Threaded passage 18 is open to bore 12 via passage 16 disposed generally perpendicular to bore 12. Referring now to FIG. 2, flow restricting device 20 has a threaded portion 26 and a flow restricting bore 22 disposed therethrough for reducing the flow rate of fluid from inlet passage 28 to passage 16. In one embodiment, device 20 is a screw made from, for example 316 S/S, and having a torques-type head 24 with a bore 22 approximately 0.052 inches in diameter extending axially from the center of the torques receptacle 24 to the end of the screw. It is to be appreciated, however, that the flow restricting device 20 of the present invention is not restricted to a single bore diameter and other flow restriction rates are contemplated. Referring back to FIGS. 1 and 1a, body 10 also defines a second inlet passage 32 having a threaded portion 34 at one end for connecting to a source of water (not shown). In one embodiment, water is supplied at approximately 2000 psi. The opposite end of the second inlet passage 32 is open to bore 12 via passage 36 disposed generally perpendicular to bore 12. In one embodiment, the first and second inlet passages 28 and 32 are sized, and threaded portions 30 and 34 are configured, for receiving a complementarily threaded 3/8 inch pipe, and passage 18 is configured to receive the threaded portion 26 of a 1/4 inch 28 tpi flow restricting device 20. Body 10 further defines an outlet passage having a threaded portion 40 for connecting, in one embodiment, to a 3/8 inch complementarily threaded pipe. Outlet passage 38 is open to bore 12 via passage 42 disposed generally perpendicular to bore 12 and directly opposite to and facing a third passage 36. The third passage 42 is further open to bore 12 via passage 44 disposed at an acute angle relative to the longitudinal axis of bore 12. The third passage 42 is also open to passage 46 which is a continuance of a fourth passage 44 toward the bottom of body 10. Passage 46 is non-functional with respect to the operation of valve system 5 and exists only to provide a path for drilling passage 44 during manufacture of body 10. In fact, after the fourth passage 44 is formed, passage 46 is typically closed at opening 48 by welding or any other equivalent method of forming a leak-proof seal. Finally, body 10 defines a threaded hole 50 extending through the side of body 10 and into bore 12 for receiving retaining screw 110 (FIG. 3). In one embodiment, hole 50 is configured to receive a 1/4 inch 28 tpi retaining screw 110. Body 10 is preferably of uniform construction and made from, for example, a material such as 304 S/S. Elongated valve member 52 is intended by the present invention to be received within bore 12 as shown by arrow 132 in FIG. 1a, for directing the flow of soap solution and water, in varying proportions, to outlet 38. To this end, valve 52 includes a cylindrical portion 66 having a bore 54 extending therethrough perpendicular to the longitudinal axis of valve 52. A sealing sleeve 90 has a pair of perpendicularly intersecting bores, 92 and 94, extending therethrough, wherein bore 92 is sized slightly smaller than the diameter of cylindrical portion 66 so that sleeve 90 may be forcibly retained on valve 52 by stretching bore 92 over cylindrical portion 66. Bore 94 is configured within sleeve 90 to allow substantial alignment of bores 94 and 54 when sleeve 90 is stretched over cylindrical portion 66. In order ho allow such stretching, sleeve 90 is required to be somewhat elastic and is preferably made of TEFLON®. Valve 52 further includes a cylindrical portion 62 adjacent to one end of cylindrical portion 66 for receiving seal carrier 96. Seal carrier 96 has a bore 98 sized to receive cylindrical portion 62 therethrough. At one end of bore 98, seal carrier 96 defines a boss 100 sized to contact a surface 64 of cylindrical portion 66. This action serves to compress sleeve 90, thereby pressing it against the walls of bore 12 when valve 52 is disposed therein. At the other end of bore 98, seal carrier 96 defines a recess sized to house a nut 106 disposed therein. A threaded portion 60 of cylindrical portion 62 defines one end of valve 52 and is configured to engage the complementarily threaded bore 108 of nut 106. Thus, when sleeve 90 is stretched onto cylindrical portion 66, and seal carrier 96 is loaded onto cylindrical portion 62 via bore 98, the threaded portion 108 of nut 106 engages the threaded portion 60 of valve 52 to thereby compress sleeve 90. Seal carrier 96 further defines a channel 104 disposed radially about bore 98 and positioned between cylindrical spools 101 and 103, also defined by seal carrier 96, for retaining a fluid seal ring 120 (FIG. 5). Valve 52 further defines a series of consecutive cylindrical spools 68, 70, 72, 76 and 75 respectively adjacent to the end of cylindrical portion 66 opposite cylindrical portion 62, Cylindrical channels 69, 71, 73 and 74 are further defined by valve 52 and are respectively disposed between the spools 68, 70, 72, 76 and 75. Channels 69, 73 and 74 are configured identically to channel 104 for retaining a fluid seal ring 120 (FIG. 5). Channel 71, on the other hand, is configured to receive the tip 114 of a set screw 110 engaged with threaded bore 50 as shown in FIG. 3. Referring to FIG. 3, set screw 110 is provided for restraining translational motion of the valve 52 after it is received within bore 12. The head of set screw 110 is preferably a 12 point bolt head. Set screw 110 must be long enough to extend through the valve body 10 and allow the tip 114 to bear against either the surface of cylindrical channel 71 or the two opposing faces of cylindrical spools 70 and 72. As shown in FIGS. 1 and 3, cylindrical spool 76 defines a bore 56 extending through valve 52 perpendicular to its longitudinal axis. Bore 56 is sized identically to bore 54, with both bores 54 and 56 being preferably 1/8 inch in diameter. However, as is most clearly seen in FIG. 3, bore 56 is radially offset from bore 54. In one embodiment, the angle of offset is approximately 30 degrees. Referring back to FIGS. 1 and 1a, the remaining end of valve 52 is defined by a cylindrical portion 78 adjacent spool 75. Cylindrical portion 78 is configured to receive a comparably sized bore (not shown) on adjustment handle 80. An outer cylindrical portion 84 of handle 80 is sized to be received within bore 14 with a predetermined loose fit so that cylindrical portion 84 may be freely rotated within bore 14. A bore 86 extends through cylindrical portion 84 perpendicular to its longitudinal axis and a pin 88 is provided which extends through bore 86 and bore 58, when handle 80 is fitted over cylindrical portion 78, thereby locking handle 80 to valve 52. Handle 80 further includes a gripping portion 82 for manually adjusting valve 52. Spools 68, 70, 72, 76, 75, 101 and 103 are generally sized identically to each other and are slidably received within bore 12 when the valve 52, handle 80, sleeve 90, seal carrier 96 and nut 106 construct is disposed within bores 12 and 14. Referring to FIG. 4, the bottom of valve body 10 includes stops 116 and 118 for restraining rotational motion of valve 52 disposed within bore 12 when valve system 5 is constructed from the various components shown in FIG. 1, the pin 88 is longer than the outer diameter of cylindrical portion 84 and should extend between the stops 116 and 118. Because pin 88 is secured to handle 80 and valve 52, stops 116 and 118 only allow rotational motion of the valve 52 within bore 12 to the extent that pin 88 is free to move between stops 116 and 118. Referring to FIG. 5, the operation of valve system 5 will now be described. With the spool valve assembly of FIG. 1 inserted into bore 12 as previously described, bore 54 is positioned at the same longitudinal position as the radially inner ends of passage 16, and fourth passage 44. Similarly, bore 56 is positioned at the same longitudinal position as the radially inner ends of passages 36 and 42. Fluid seal rings 120 have been positioned within channels 69, 73, 74 and 104 as previously described to retain soap solution in the vicinity of bore 54 and water in the vicinity of bore 56, thereby preventing commingling of the two fluid sources within bore 12 and further preventing leakage of the two fluids out of bore 12 arid valve body 10. Fluid seal rings 120 must be capable of forming an acceptable fluid seal and must further be resistant to chemicals such as detergents and solvents that may be present in the soap solution. In one embodiment, the fluid seal rings 120 are VITON® "O" rings. Since bore 54 is radially offset with respect to bore 56 as previously described, rotational movement of valve 52 via handle 80 will result in differing proportional mixtures of soap solution and water emerging from outlet passage 38. When handle 80 is positioned such that bore 56 is axially aligned with passages 36 and 42, so that bore 56, passage 36, and third passage 42 are disposed coaxially, water entering second inlet passage 32 flows through second inlet passage 32, bore 56, third passage 42 and through outlet passage 38. Because bore 54 is offset with respect to bore 56, soap solution entering passage 16 does not flow through bore 56, but is instead sealed from bore 12 via sleeve 90. With valve 52 so positioned, the mixture emerging from outlet passage 38 comprises approximately 100% water and 0% soap solution. As handle 80 is rotated in the direction of arrow 130, bore 56 begins-to move out of axial alignment with passages 36 and 42, thereby decreasing the flow of water into outlet 38. At the same time, bore 54 begins to move closer toward axial alignment with passages 16 and 44. As used herein, bore 54 is in "axial alignment" with passages 16 and 44 when one end of the bore 54 is disposed adjacent to the radially inner end of passage 16, and the other end of the bore 54 is disposed adjacent to the radially inner end of passage 44. As bore 54 moves closer toward axial alignment, some soap solution passes through inlet passage 28, flow control device 20, passage 16, bore 56 and into diagonal fourth passage 44. The water flowing through third passage 42 and into outlet passage 38 then draws the soap solution from fourth passage 44 and mixes the two fluids in venturi-like fashion to provide a mixture emerging from outlet passage 38 comprising somewhat less 100% water and somewhat more than 0% soap solution. As handle 80 continues to rotate in the direction of arrow 130, a position is reached wherein the amount of soap solution flowing through bore 54 and into fourth passage 44 is equal to the amount of water flowing through bore 56 and into third passage 42. This conditions thus provides for a mixture emerging from outlet passage 38 of approximately 50% soap solution and 50% water. It can be appreciated that because the water pressure at the water inlet (second) passage is greater than the soap solution pressure at inlet passage 28, there exists the possibility that water may back flow through passage 44, bore 54, passage 16, flow control device 20, first inlet passage 24 and into the source of soap solution (not shown). To avoid possible contamination of the soap solution source, a check ball valve (not shown), or similar mechanism, may be installed within inlet chamber 28 so that back flow of water into the soap solution source can be inhibited. In situations where soap solution may back flow into the water source, a check ball valve, or similar mechanism, may also be installed within inlet chamber 32 to inhibit such back flow. As handle 80 continues to rotate in the direction of arrow 130, a position will be reached wherein bore 54 will be axially aligned with passages 16 and 44, and bore 56, because of its offset with respect to bore 54, will not be in fluid communication with either passage 36 or passage 42. This condition thus results in a mixture emerging from outlet passage 38 of approximately 0% water and 100% soap solution. In one embodiment, some water flowing into second inlet passage 32 will flow into outlet passage 38 via third passage 42 because the diameter of cylindrical portion 76 is sized to be slightly less than the diameter of bore 12 to allow valve 52 to be slidably received therein. Some water will thus be able to flow around cylindrical portion 76 and into third passage 42 thereby decreasing the proportion of mixture emerging from outlet passage 38 to somewhat more than 0% water and somewhat less than 100% soap solution. However, the present invention contemplates the engagement of a sleeve, such as sleeve 90, to cylindrical portion 76 to thereby inhibit the flow of water into third passage 48 when fluid communication from passage 36 to third passage 42 through bore 56 is disallowed. From the foregoing, it can be appreciated that the valve system 5 of the present invention allows continuous analog control of the proportional quantities of soap solution and water emerging from outlet passage 38 from approximately 0% water, 100% soap solution, to 100% waiter, 0% soap solution. Two mechanisms inherent in the design of valve system 5 also make it possible to operate multiple identical valve systems from a common soap solution source and common water source without adversely affecting the fluid pressure required by each user. First, flow reducing device 20 significantly reduces the flow rate of soap solution entering passage 16 from that entering inlet passage 28. Similarly, the size of bore 56 significantly reduces the flow rate of water entering third passage 42 from that entering first inlet passage 32. This mechanism results in allowing a user to operate valve system 5 within the aforementioned extremes while maintaining essentially constant fluid pressures at the first and second inlet passages 28 and 32. Second, the maximum flow rate of fluid through either bore 54 or 56 occurs only when the bore is axially aligned with its respective fluid communication passages. In other words, the maximum flow rate of water through bore 56 occurs only when bore 56 is axially aligned with passages 36 and 42, and the maximum flow rate of soap solution through bore 54 occurs only when bore 54 is axially aligned with passages 16 and 44. Thus, as valve 52 is rotated so that either bore 54 or 56 is moved away from axial alignment with its respective passages, the flow rate of fluid therethrough is diminished. This then results in less fluid demand from the respective fluid source and further acts to maintain constant fluid pressures at inlet passages 28 and 32. While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected.

A valve system for mixing two pressurized liquids, A and B, in varying proportions ranging from 0% liquid A, 100% liquid B to 100% liquid A, 0% liquid B comprises two liquid inlet passages, a mixture outlet passage, and a spool valve disposed therebetween for directing the desired proportions of liquid to the outlet passage. The liquid proportions are adjusted by rotating the spool valve between two predetermined stops thereby allowing incoming fluids to flow at different rates into offset bores extending through the spool valve. Such a valve system is useful in vehicle and aircraft cleaning systems wherein one liquid comprises a soap solution and the other comprises water.

big_patent

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of compressing gas in a compressor station for a gas pipe line, particularly in permanent frost areas. The method includes compressing the gas delivered in the pipeline with an entry pressure in a compression procedure to a higher pressure, subsequently cooling the gas by a heat exchange and again feeding the gas for the further transportation to the pipeline with a lower exit temperature, particularly an exit temperature of at most 0° C., and with an increased exit pressure as compared to the entry pressure. The present invention also relates to an arrangement for carrying out the method. 2. Description of the Related Art Natural gas is transported today in very large quantities frequently over distances of several thousand kilometers in large gas pipelines to the centers of consumption. For example, such long-distance gas pipelines may have a diameter of 56 inches and may be operated with gas pressures of 75 bar or even up to 100 bar, in order to achieve a transportation capacity which is as large as possible. Because of the unavoidable pressure loss along the gas pipelines, the compressor stations must be provided at certain intervals for increasing the gas pressure back to the nominal pressure. As a rule, the compressors used for this purpose, usually turbo compressors, are driven by gas turbines which use a portion of the transported natural gas as fuel. A very large portion of the known natural gas reserves are located in so-called permanent frost areas, i.e., in areas in which the ground thaws during the summer months only to a depth of about 80 to 100 cm and remains otherwise permanently frozen. The gas pipelines are usually placed at a depth in the ground where permanent frost prevails. Since the soil frequently becomes very soft in the thawed state, it must be ensured that the gas pipeline does not result in thawing of the ground because the pipeline would otherwise at least at certain locations sink lower and lead to mechanical stresses in the pipe wall which may lead to pipe ruptures. Heating of the soil is a possibility because the compression of the gas in the compressor inevitably also results in a temperature increase. Therefore, the gas compressed to nominal pressure is conventionally cooled before being returned into the pipeline, wherein a maximum temperature of approximately 0° C. must be maintained. If possible, a temperature of - 5° C. is desirable. Because of the low outside temperatures substantially below 0° C., the required cooling poses no problems during the winter months and can be easily carried out by gas/air coolers. However, during the transition periods and particularly in the summer months, during which maximum day temperatures of 15° to 20° C. are possible, the gas coolers are inevitably no longer sufficient. For this reason, special re-cooling plants with separate cooling cycle, i.e., refrigerating or cooling machines in which propane in particular is used as a cooling agent, are used in such compressor stations during the warm weather periods. The use of re-cooling plants of the conventional type poses several problems. The re-cooling plants are very expensive and constitute a large portion of the total investment for a compressor station. In addition, there is the fact that the plant is completely unused during the major portion of a year, i.e., for eight months. In addition, there is a safety problem with respect to possible leakages because the propane as cooling agent is not only easily flammable, but is also heavier than air and, therefore, has a reduced volatility, so that the explosion risk is substantially increased. SUMMARY OF THE INVENTION Therefore, it is the primary object of the present invention to propose a method of the above-described type and an arrangement for carrying out the method in which the required investments and operation risk are substantially reduced. In accordance with the present invention, the method of the above-described type includes the steps of compressing the gas at least during individual intervals to a substantially higher pressure (excess pressure) than the desired exit pressure, cooling the compressed gas by the heat exchange to a temperature above the exit temperature, and obtaining the further cooling to the desired exit temperature by expanding the gas from the excess pressure to the desired exit pressure. A compressor station for a gas pipeline for carrying out the above-described method includes at least one compressor for compressing gas, at least one heat exchanger for cooling compressed gas, additionally valve-controlled pipelines for connecting the compressor and the heat exchanger to one another and to the gas pipeline, as well as control units for controlling the compressor and the valves. In accordance with the present invention, an electronic control is provided which operates in such a way that at least one compressor carries out a compression of the gas to an excess pressure which is substantially above the desired exit pressure. In addition, an expanding unit is provided for expanding the compressed gas, wherein the electronic control is operated in such a way that the expansion takes place until the desired exit pressure is reached. The present invention starts from the fact that it is known to carry out the compression of a gas supplied at an entry pressure below the nominal pressure (rated pressure of the gas pipeline) to an increased pressure, wherein the compression can be carried out in a single stage or in multiple stages in compressors which are connected in series. Between the compressor stages and particularly after the last compressor stage, cooling by heat exchange takes place (usually air/gas heat exchange), in order to reach the required lower exit temperature of at most 0° C., preferably -5° C., for the re-entry of the compressed gas into the gas pipeline. During the warmer period of the year, in which the use of re-cooling units was necessary in the past for ensuring the required exit temperature, the present invention provides for a different type of cooling. The present invention utilizes the known physical effect according to which a compressed gas is inevitably cooled when expanded to a lower pressure, either by throttling or with the simultaneous performance of work. In order to ensure the required exit pressure or nominal pressure at the exit of the compressor station, the present invention provides that the gas to be transported is compressed to an excess pressure which is substantially above the exit pressure, for example, 10 to 50 bar above the exit pressure, to carry out at the end of the single-stage or multiple-stage compression a cooling by heat exchange, particularly by air/gas heat exchange, and subsequently to expand the compressed gas to the desired exit pressure. The excess pressure is selected in such a way that, taking into consideration the extent by which the gas compressed to excess pressure can be cooled by heat exchange, cooling during expansion is sufficient for obtaining a temperature reduction at least to the desired exit temperature of the gas for the re-entry into the gas pipeline or transportation. These parameters can be easily computed with the aid of the existing limiting or boundary conditions. The expansion can be carried out in a simple manner, for example, by means of a valve. However, a more significant cooling effect can be achieved if the compressed gas additionally performs work during the expansion, as this is possible in an expansion turbine. This embodiment of the invention is particularly recommended for the operation during the summer months, and this embodiment provides the additional advantage that the recovered mechanical energy can be utilized for providing a portion of the drive energy for the compression of the gas to the intended excess pressure. A particularly advantageous embodiment of the present invention provides that the compression to the excess pressure is carried out in a total of three stages, wherein a predominant portion of the compression takes place in two successive primary., compression stages which are equipped with machines which produce approximately the same pressure ratio. This provides the advantage that the compressors of the primary compression stages may be essentially of the same construction. Only the compressor housing of the subsequent compressor or compressors must be dimensioned for a higher pressure than the housing of the compressor or compressors of the first primary compression stage. Between the two primary compression stages, the gas heated in the first primary compression stage is cooled preferably by air/gas heat exchange. When the compressed gas leaves the second primary compression stage, the gas has not yet reached the desired excess pressure. The desired excess pressure is reached in an additional compression stage which includes a booster compressor. Subsequently, the gas is again cooled, preferably by means of an air/gas heat exchange. An expansion with simultaneous performance of work is then carried out in an expansion turbine. The latter is coupled, for example, mechanically to the booster compressor of the additional compression stage and is the sole drive means for the booster compressor, so that a significant portion of the total drive energy required for producing the excess pressure can be recovered and is not lost. The above-described manner of carrying out the method in two primary compression stages with compressors having approximately the same pressure ratio provides the significant advantage that the compressors used in the stages can be completely exchanged for one another, as long as they are operated with the maximum permissible pressure of the first primary compression stage. The possibility of exchanging the compressors is of particular interest because the requirements with respect to the rate of flow through the pipeline, i.e., the required nominal pressure in the pipeline, on the one hand, and the environmental conditions for cooling by heat exchange, on the other hand, are subject to substantial changes during the course of the year. During the cold season, during which the cooling can be ensured without problems by heat exchange alone, the pressure achievable with one primary compression stage (i.e. single-stage) is already sufficient, so that cooling by expansion from an even higher excess pressure becomes superfluous. On the other hand, during the warmer season, the insufficient cooling by heat exchange means that the amount of gas required is usually lower, for example, 10 to 15% lower, than in the cold season, so that it is possible to operate with a pipeline pressure which is lower as compared during the winter season. Consequently, the actually required excess pressure can be selected lower, and, in order to still achieve the required temperature level, the expansion can be carried out instead to a nominal pressure which is lower than the nominal pressure during the cold season. Because of these conditions, not only the operation in the warm season can be carried out inexpensively and with a comparatively small quantity of energy; there are also advantages with respect to the operation during the cold season because the compressors of the second primary compression stage can be operated parallel with the compressors of the first primary compression stage, i.e., under the same pressure conditions. For this purpose, the connecting pipelines to the inlets and outlets of the compressors are switched to parallel operation by means of a suitable valve control. Since several compressors of the same type already operate in parallel in each primary compression stage, and since all compressors never have to be used even during peak load periods, in addition to already existing stand-by machines, additional compressors are available which can be used as needed during breakdowns or when maintenance has to be performed. As compared to the prior art in which special re-cooling units are used which can only be used efficiently during the warm season, i.e., in summer operation, the present invention provides an altogether better possibility of using the principal units of the compressor stations throughout the entire year. The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of the disclosure. For a better understanding of the invention, its operating advantages, and specific objects attained by its use, reference should be had to the drawing and descriptive matter in which there are illustrated and described a preferred embodiment of the invention. BRIEF DESCRIPTION OF THE DRAWINGS In the drawing: FIG. 1 is a schematic diagram showing an embodiment of a compressor station according to the present invention during summer operation; and FIG. 2 shows the compressor station of FIG. 1 during winter operation. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIGS. 1 and 2 of the drawing, those connecting pipelines through which the gas flows during the respective type of operation are shown in thick lines and the pipelines which are closed off by valves are shown in thin lines. In the illustrated embodiment, the gas pipeline has two parallel line strands 1a, 1b. The pressure in the pipeline which may have dropped at the entry into the compressor station to, for example, 50 bar, is to be raised again to reach a nominal pressure of, for example, 75 or 100 bar, at the exit of the compressor station. The gas pipeline 1a, 1b initially leads into a purifying unit 2a and 2b, respectively, which may be constructed as cyclone separators with or without filters and serve to separate undesirable impurities, such as moisture, dust, etc. from the gas. Subsequently, the gas is conducted into the first primary compression stage with the compressors 3a and 3b which are driven by gas turbines 4a and 4b, respectively. The fuel for driving the gas turbines 4a and 4b is removed from the gas line 1a or 1b, respectively, in a manner not illustrated in detail. The compression taking place in the compressors 3a and 3b increases the temperature of the gas. This temperature is again reduced by a subsequently arranged heat exchanger 5a, 5b which is preferably constructed as an air/gas heat exchanger. The gas cannot yet be returned to the pipeline 1a, 1b because cooling by the heat exchange cannot be carried out to a temperature which is low enough. This is because the external temperatures of the air are too high during the summer operation and, consequently, the temperatures of the cooling agent are too high. Since the valves V 4a and V 4b , in the gas pipeline 1a, 1b are closed, the compressed gas flows into the connecting pipeline L 2a , L 2b and is conducted into a second primary compression stage with the compressor 6. For this purpose, the connecting pipelines L 2a and L 2b lead into a common supply line (line L 3 ) of the compressor 6. This line L 3 can also be connected directly to the purifying units 2a, 2b through the connecting pipelines L 1a and L 1b . However, during summer operation, these connections are locked by the valves V 11 and V 1a , V 1b . The compressor 6 is driven by a gas turbine 6 which, as is the case in the gas turbines 4a, 4b of the first primary compression stage, removes a portion of the gas from the gas pipeline 1a or 1b to be used as fuel. Immediately following the compressor 6, the line L 3 branches and leads to an additional compression stage with compressors 8a, 8b (booster compressors) which are connected in parallel and raise the pressure of the gas to a previously determined excess pressure. Following the additional compressors 8a, 8b, the compressed gas which has been heated as a result is again conducted to a heat exchanger 10 (preferably air/gas heat exchanger) for cooling the gas to a temperature corresponding to the ambient temperature. The line L 3 can also be switched in such a way that a direct connection between the compressor 6 and the heat exchanger 10 is obtained. However, in the case of summer operation shown in FIG. 1, this direct connection is locked by a valve V 5 . After leaving the heat exchanger 10, the line L 3 branches into supply pipelines L 4a and L 4a which lead to expansion turbines 9a and 9b. In the expansion turbines 9a and 9b, the gas is expanded from the excess pressure to the nominal pressure of the pipeline 1a, 1b while simultaneously performing work. As a result, the gas is cooled to such an extent that it can be returned behind the closed valves V 4a and V 4b at the required nominal pressure and the desired nominal temperature to the pipeline 1a and 1b. In the illustrated embodiment, the expansion turbines 9a and 9b are coupled to the additional compressors 8a and 8b, and they meet the drive energy demand of these compressors. The heat exchanger 10, as is the case in the heat exchangers 5a, 5b, is constructed as a gas/air cooler, can also be connected directly through the pipelines L 5a and L 5b to the two pipeline strands 1a, 1b. However, during summer operation, this connection is closed by the valves V 3 and V 2a , and V 2b . With respect to the actuation of the individual valves and the control of the compressors and the turbines, the entire compressor station is controlled by an electronic control system, not illustrated in FIGS. 1 and 2. In accordance with a useful feature of the present invention, the compressor station would not be constructed in the manner schematically illustrated in FIG. 1 for simplicity stake. Rather, instead of single compressors, each of the two primary compression stages would have several compressors connected in parallel. For example, each pipeline strand 1a, 1b would have in the first primary compression stage three primary compressors 3a and 3b with a stand-by machine, i.e., altogether 2×(3+1) primary compressors 3a, 3b (in a 56 inch double gas line at 75 bar operating pressure with 16 MW units and at 100 bar operating pressure with 25 MW units), wherein corresponding gas turbines 4a, 4b are provided as drive units. A smaller number of primary compressors 6 (connected in parallel) is sufficient in the second primary compression stage because the pressure increase effected up to then also results in a corresponding volume reduction of the compressed gas. For example, in view of the above-mentioned equipment of the first primary compression stage, it would be useful to have four primary compressors 6 and an additional stand-by machine, i.e., altogether five compressors 6. Instead of the expansion turbines 9a, 9b, it is also possible to use simple throttling devices for pressure reduction. However, this would mean that the temperature decrease of the gas resulting from the pressure reduction would be substantially less, i.e., for obtaining the same final temperature, under otherwise the same conditions the excess pressure would have to be even higher. In addition, no drive energy could be recovered and, therefore, the specific energy consumption of the compressor station would be accordingly higher. Therefore, the use of expansion turbines is preferred. However, if the expansion turbines are not used, it is apparent that the excess pressure can be produced in the transition phase only in two stages. As is the case in the three-stage compression using two primary compression stages and an additional compression stage, it is preferred to provide compressors 3a, 3b and 6 which have approximately the same pressure ratio in order to make it possible to use compressors which are as much as possible of the same construction. When the outside temperatures (winter operation) are sufficiently low, cooling of the gas by pressure expansion is no longer necessary. As FIG. 2 shows, the present invention provides that during the cold season the compressor station is operated differently by switching the valves to essentially obtain a parallel operation of the compressors. The valves V 1a , V 1b , V 2a , V 2b , V 3 , V 4a , V 4b , V 5 , are all open and, in order to simplify FIG. 2, are not shown in FIG. 2. After flowing through the heat exchangers 5a, 5b the gas compressed in the primary compressors 3a, 3b to the nominal pressure of, for example, 75 bar or 100 bar, can already be supplied at a temperature of below 0° C. to the gas pipeline 1a, 1b.The compressors 3a, 3b can produce the required throughput quantity together with additional units of the compressor 6 because the latter, contrary to the summer operation, can produce a portion of the required flow rate since they are connected in parallel. For this purpose, the gas having a low entry pressure reaches through the pipelines L 1a , L 1b , L 3 the compressor or compressors 6 in which the gas is compressed in one compression step to the required nominal pressure. The additional compressors 8a, 8b are switched off during winter operation by closing the valves V 7a , V 7b , V 8a , V 8b . As is the case in the primary compressors 3a, 3b, the compressed, heated gas is initially conducted for cooling to the required exit temperature into the heat exchanger 10 and is then returned through the lines 5a, 5b into the gas pipeline 1a, 1b. The connecting pipelines L 2a , L 2b and L 4a , L 4b are closed by the valves V 6a , V 6b , V 12a , V 12b and V 9a , V 9b , V 10a , V 10b which are not illustrated in FIG. 1. For example, during normal winter operation, 2×3 compressors 3a, 3b of the first primary compression stage and two parallel compressors of the second primary compression stage may be in continuous operation. In addition, a stand-by machine is available at each pipeline strand 1a, 1b and even three stand-by machines are available in the parallel second primary compression stage. These stand-by machines can be put into operation in case of interruptions or for the purposes of maintenance without reducing the throughput quantity. The above-described configuration is particularly useful for double-strand long-distance pipelines having a diameter of 56 inches and operated at a pressure of 100 bar with the use of 25 MW turbine sets or at 75 bar with the use of 16 MW turbine sets. The effectiveness of the method according to the present invention under the conditions of summer operation (about three to four months of the year) becomes clear from the following example which is described with respect to the configuration of the arrangement shown in FIG. 1. It is assumed that natural gas enters the purifying units 2a, 2b at the pipeline beginning at a production source from a separation plant with a temperature of approximately 15° C. and a pressure of approximately 50 bar. The nominal entry temperature into the pipeline 1a, 1b for further transportation is at most 0° C. The required pipeline pressure results as a function of the required throughput quantity. When the natural gas is compressed in the primary compressors 3a3b, it is heated to approximately 60° to 80° C. (corresponding to the pressure ratio in the compressor) and is then cooled to 25° C. in the air/gas heat exchangers 5a, 5b. The heat exchangers 5a, 5b and the pipelines within the compressor station result in a pressure loss of about 2 bar. A further compression in the subsequent primary compressor 6 produces an intermediate pressure, which causes the temperature of the natural gas to increase to approximately 50° to 60° C. The subsequent additional compressors 8a, 8b increase the pressure further to the desired final pressure or excess pressure which causes a temperature rise to about 80° C. Immediately subsequently, the compressed gas is again cooled in the heat exchanger 10 to a temperature of about 25° C. and the gas is then expanded in the expansion turbines 8a, 8b to the pipeline pressure, for example, 75 bar. As a result, the compressed natural gas has a temperature of approximately -5° C. to ±O° C. when entering the gas pipeline. The respective expansion pressure is determined by the ambient temperature and the throughput quantity through the line. Because of the recovery of drive energy in the expansion turbines, the quantity of energy required for such a compressor station is not higher than in a comparable compressor station using conventional re-cooling technology on the basis of a closed propane cooling cycle. The important aspect is the fact that the investment required for a plant according to the present invention is substantially lower, approximately by 40 to 45 % percent than for a plant utilizing conventional re-cooling technology. This not only results in an increase of the availability of the overall plant, but also in a reduction of the risk of accidents due to the fact that re-cooling units are not present. The invention is not limited by the embodiments described above which are presented as examples only but can be modified in various ways within the scope of protection defined by the appended patent claims.

A method and an arrangement for compressing gas in a compressor station for a gas pipeline, especially in areas of permanent frost, wherein the gas is supplied in the gas pipeline to the compressor station at an entry pressure and the gas is returned to the pipeline for further transportation in the pipeline at a desired exit temperature and at an exit pressure which is higher than the entry pressure. The gas is initially compressed at least during individual time intervals to an excess pressure which is substantially higher than the desired exit pressure. The compressed gas is then cooled by heat exchange to a temperature above the desired exit temperature. Finally, the gas is further cooled to the desired exit temperature by expanding the gas from the excess pressure to the exit pressure.

big_patent

BACKGROUND When electronic components operate, they produce heat. In some, low power, applications, this heat can be adequately removed using free convection cooling. However, in many applications, free convection cooling (the un-aided movement of air) does not provide sufficient cooling to prevent overheating (and possibly premature failure) of electronic components. In applications where free convection cooling does not offer sufficient cooling capacity, electric fans are often used as a low cost way of moving ambient air across the electronic components at a higher rate than that possible using free convection cooling. Accordingly, the use of cooling fans is often employed as a low cost solution for keeping electronic components operating within the acceptable temperature ranges specified by the electronic component manufacturers. Cooling fans are often integrated with an enclosure which houses, amongst other components, the electronic components to be cooled by the fan. The cooling fan is often mounted to the enclosure using fasteners such as screws, dowel pins, rivets, or the like. Although this fastening technique is widely used, it significantly increases the cost of the product due to the labor and tools that are needed to install the fasteners and the handling costs associated with handling the fasteners. Embodiments set forth herein disclose a system for eliminating fasteners traditionally used for securing cooling fans to an enclosure. The embodiments disclosed herein can be utilized in various applications including the automotive, computer, electronic instrumentation, or in any industry where the forced movement of air is used as a temperature controlling medium. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an isometric view of an embodiment of the cooling fan mounting system of the present invention used in conjunction with a computer tower. FIG. 2 is an exploded enlarged isometric view of encircled portion 2 of FIG. 1 from a different perspective. FIG. 3 is a partial cross-sectional view taken substantially through lines 3 - 3 of FIG. 2 . FIGS. 4A-4I are a series of grouped interior, exterior, and side views of the position of the fan enclosure (with respect to the panel on which it is mounted) at various stages of fan assembly installation. DETAILED DESCRIPTION Now referring to FIG. 1 , an embodiment of the cooling fan assembly 12 of the present invention is shown in use with a panel 14 of computer tower 10 . Although cooling fan assembly 12 can be used in any computer application where forced air cooling is necessary, it is not limited to those applications and one skilled in the art will readily recognize that the cooling fan assembly of the present invention is applicable in any application where forced air movement is relied upon for adequate cooling of any heat generating system (electrical, mechanical, chemical, or the like). Now referring to FIG. 2 and FIG. 3 , panel 14 can comprise any stationary member to which cooling fan assembly 12 is to be mounted. However, typically cooling fans are mounted to sheet-like stationary members (typically sheet metal panels). Throughout this disclosure, the device to which assembly 12 is mounted will be primarily referred to as a panel or stationary member; however, structures other than panels are fully contemplated within the scope of this disclosure. Panel 14 provides the mounting interface for supporting cooling fan assembly 12 . Cooling fan assembly 12 includes a motor 16 which is used to rotate a fan blade 18 by way of a motor output shaft 20 . In one embodiment of the present invention, motor 16 is an electrical motor which receives its electrical power requirements via power conductors 22 . Although in many applications, the preferred embodiment of motor 16 is an electric motor, it is well within the scope of this invention to use non-electric motors as the primary mover for moving fan blade 18 . Other primary movers that might be appropriate in various applications, include hydraulic motors, pneumatic motors, and the like. In some embodiments, depending on the type of electric motor that may be used, it may be convenient or cost effective to mount electronic motor control components 24 on, or about, motor 16 . In other applications, it may not be appropriate to mount motor control components on, or about, motor 16 and in such cases, motor control components 24 can be mounted separate from motor 16 . In the majority of applications, it is most appropriate to establish the rotation of fan blade 18 such that it moves warm air, designated by arrows 26 , from the interior of an enclosure to the exterior of the enclosure through enclosure exhaust portals 28 . The enclosure is typically fitted with enclosure intake portals (intake portals not shown) which allow ambient air to enter into the enclosure interior to replace the air exhausted by cooling fan assembly 12 . In one embodiment the motor 16 includes non-rotatable housing 30 which houses the operative components of motor 16 . The housing 30 is coupled to a motor carrier 32 . In one embodiment of the present invention, motor housing 30 is integrally formed (such as using plastic injection molding techniques) with motor carrier 32 to form an integrated unit. Motor carrier 32 includes a plurality of mounting legs 34 . In one embodiment, each mounting leg 34 terminates into a pair of resilient leg portions 36 which are separated by a compression gap 38 . Each leg portion 36 may terminate into a turned-out portion 52 . Panel 14 may include a plurality of recess portions 40 which are convex with respect to the enclosure interior (i.e. are depressed into the enclosure interior and away from the enclosure exterior). In one embodiment, there is a recess portion 40 to correspond with each of the plurality of mounting legs 34 . Recess portion 40 includes an opening 42 which is shaped to include an enlarged opening region 44 and a residual opening region 46 (see FIG. 2 ). In one embodiment, the motor carrier 32 also includes a plurality of spring members 48 . Spring members 48 are designed to urge motor carrier 32 away from panel 14 once the plurality of mounting legs 34 are in their fully seated position. This urging function provided by spring members 48 prevents motor carrier 32 from moving (due to the vibrational forces imparted to it during normal operation of motor 16 ) and becoming disengaged from its seated position. This feature will be discussed more fully in conjunction with FIGS. 4A-4I . In one embodiment, the height of turned-out portions 52 is less than or equal to the height of recessed portion 40 . By sizing turned-out portions 52 and recessed portions in this way, turned out portions 52 will not extend beyond the plane defined by the enclosure exterior thereby allowing one or more adjacent components (not shown) to directly abut the exterior of the enclosure. Now referring to FIGS. 4A-4F , the steps for installing the cooling fan assembly 12 of the present invention are depicted. The initial positioning of the cooling fan assembly 12 against panel 14 is shown in FIGS. 4A-4C and is hereinafter referred to as the load position. In the load position, cooling fan assembly 12 is brought adjacent panel 14 such that the turned-out portions 52 of each mounting leg 34 are inserted into a respectively associated enlarged opening region 44 of opening 42 . Each turned-out portion 52 of the resilient legs 36 is sized in relation to its associated enlarged opening 44 such that the turned-out portions 52 freely pass into enlarged opening 44 without restriction. An interior view of the load position is shown in FIG. 4A and an exterior view (e.g. the view as seen from the exterior of enclosure 10 ) is shown in FIG. 4B . FIG. 4C shows a side view of the load position. It is important to note that in the load position, before any exertion force (designated by arrow 54 ) is applied to cooling fan assembly 12 , cooling fan assembly 12 rests against a surface of panel 14 by virtue of the contact between the bottom most bowed portion of spring member 48 and the panel 14 (see FIG. 4C ). It is also important to note that before any exertion force is applied against cooling fan assembly 12 toward panel 14 , the turned-out end portions 52 of each resilient leg 36 do not pass completely through enlarged opening 44 of opening 42 . In the load position, because enlarged opening 44 is sized larger than the turned-out portions 52 of resilient legs 36 , no compression forces are exerted against pairs of resilient leg portions 36 and the compression gap 38 is at its maximum size. Now referring to FIGS. 4D-4F , in order to move the cooling fan assembly 12 from the load position ( FIGS. 4A-4C ) into the partially installed position ( FIGS. 4D-4F ), a combined compressive 54 and a rotating 56 force (arrows) must be imparted to at least one of the cooling fan assembly 12 or the panel 14 . The compressive force 54 acts to compress spring member 48 and move turned-out portions 52 fully into recess 40 , while the rotating force 56 repositions resilient legs 36 into an intermediate sized opening 58 of opening 42 . By comparing the length of dimension 50 between FIG. 4C and FIG. 4F , it is easily seen that dimension 50 in FIG. 4F is much smaller than it is in FIG. 4C . This is a depiction of the compression of spring 48 . Intermediate opening 58 is smaller than enlarged opening 44 which acts to bring together each pair of resilient leg portions 36 when rotating force 56 is exerted. Intermediate opening 58 is sized sufficiently small such that the turned-out portions 52 of each resilient leg 36 cannot pull through intermediate opening 58 under the urging of compressed spring member 48 . Now referring to FIGS. 4G-4I , as cooling fan assembly 12 is further rotated 56 from the partially installed position (as shown in FIGS. 4D-4F ) into the fully installed position (shown in FIGS. 4G-4I ), resilient leg portions 36 of each mounting leg 34 enter into a third portion of opening 42 called the residual opening 60 . Residual opening 60 is sized smaller than enlarged opening 44 but not as small as intermediate opening 58 . Thus, when each pair of resilient leg portions 36 transition from the intermediate opening 58 into residual opening 60 , they spring outwardly. This outward movement captures each leg portion pair 36 within its respectively associated residual opening 60 . The relative compression experienced by each pair of resilient leg portions 36 at each stage of installation can be seen by comparing the size of the compression gap 38 as the installation progresses from the load position ( FIG. 4B ) through the partially installed position ( FIG. 4E ) and, finally into the fully installed position ( FIG. 4H ). In the fully installed position, spring member 48 remains in a compressed state thereby urging turned-out portions 52 of resilient leg portions against the exterior surface of panel 14 . This urging function performed by the spring member 48 assists in preventing vibrational noise from developing between the motor carrier 32 and the panel 14 and also serves to prevent vibrational forces from causing resilient leg portions 36 from “backing out” of their respectively associated residual opening 60 . Having described various embodiments of the present invention, it will be understood that various modifications or additions may be made to the preferred embodiments chosen here to illustrate the present invention without departing from the spirit of the present invention. For example, the embodiment of spring member 48 shown in the drawings is generally depicted as a compressible “bowed” member; however, any device which is capable of exerting an urging force between cooling fan assembly and panel 14 is within the contemplation of this disclosure. Accordingly, it is to be understood that the subject matter sought to be afforded protection hereby shall be deemed to extend to the subject matter defined in the appended claims (including all fair equivalents thereof).

A mounting system for mounting a rotary member to a stationary member. The mounting system includes a carrier adapted to engage the rotary member, wherein the carrier includes a mounting leg portion which terminates into a pair of resilient leg portions. The carrier may also further include a spring member adapted to engage a first surface of the stationary member. At least one of the legs in the pair of resilient leg portions includes a turned-out portion adapted to engage a second surface of said stationary member.

big_patent

CROSS-REFERENCE TO RELATED APPLICATIONS Not Applicable STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT Not Applicable BACKGROUND OF THE INVENTION Spacecraft structures require the use of advanced lightweight and stiff composite materials in their design to meet the projected weight efficiencies of some current and most future space missions. Unfortunately, these lightweight composites, unlike bolted metallic structures, have very little inherent damping or vibration dissipation characteristics. Thus, due to their light weight and low damping, many structural subsystems with their instruments and electronic payloads, may be subjected to dangerously high vibration levels which compromise their functionality. Of particular interest here are instruments mounted on precision kinematic mounts (KM). Due to their construction techniques, these KM's have very little inherent damping, thus accentuating instrument vibration environment during flight. These environmental effects are brought about during powered flight and pyrotechnic separation/release events. In fact, 14% of spacecraft launches through 1984 (600 launches) suffered vibration/shock related failures. Of these failures, 50% resulted in catastrophic mission loss. Currently, there are on-going efforts to define graphite structure modifications which lower the overall level of vibration response throughout spacecraft structures. Test and analysis results from a number of space projects using constructions of lightweight graphite composites indicate that the level of reduction likely to be achieved may not be sufficient to bring already developed instruments within their design levels. The need thus arises to identify and make ready for development additional vibration reduction techniques for instruments should the spacecraft structure reduction be proven to be insufficient. In FIG. 1, the instrument 10 is represented by a rectangular solid depicted by broken lines. The instrument 10 is supported by six small precision ground flat pads 12, 14, 16, 18, 20, 22 which only resist loads perpendicular to their plane (individually, they cannot resist bending moments). Under gravity, the three pads 12, 14, 16 support the weight of the instrument 10, i.e., they provide restraint in the z direction. In addition, they restrain the instrument 10 against rotations along the x and y axes. Pads 18, 20 restrain the instrument 10 against translation along the y axis and rotation along the z axis. Finally, pad 22 restrains it against translation along the x axis. In practice however, it is very difficult to design a linear system of supports which will only provide restraints against translations and none in rotation (i.e. bending action). Conventional designs of three kinematic mounts are depicted in FIGS. 2A-2C. The three mounts are denoted by 24, 30 and 36 in FIGS. 2A-2C, respectively. They comprise a collection of bars 30, 32, 34, 38, 40, 42, 44 attached together. The mount 24 (FIG. 2A) is designed to restrain the instrument predominantly in the axial direction along the longitudinal axis of bar 30, as shown by the arrow 25. At the top and bottom of bar 30, notches 26, 28 have been machined to simulate hinge action, and thus minimize restrains against lateral translations and rotations along three axes. In like manner, mounts 30 (FIG. 2B) and 36 (FIG. 2C) are designed to provide translation restraints predominantly in two and three directions as shown by arrows 31 and 37, respectively. Instruments have been mounted to spacecraft via conventional arrangements of mounts 24, 30 and 36. For a given instrument, particular performance requirements are formulated that specify the maximum values of stiffness the extra restraints can have, which are in excess of the six required for an ideal kinematic mount. Kinematic mounts, such as those shown in FIG. 2 have met with limited success. Even though these mounts are designed to safely carry the launch loads, the designs have no provisions to minimize loads transmitted to the instrument 10. In particular, the six suspension modes introduced by the mounts are expected to have very little damping, thus amplifying flight loads to the mounted instrument 10. BRIEF SUMMARY OF THE INVENTION It is an object of the present invention to provide kinematic mounts which incorporate novel damping features. It is another object of the present invention to provide a kinematic mount having a passive energy dissipating mechanism to protect the instrument from potentially damaging flight loads. It is a corollary object of the present invention to provide a kinematic mount that may be incorporated on existing KM structures. It is a further object of the present invention to provide a kinematic mounting scheme which uses six identical strut elements in order to greatly reduce manufacturing complexity and costs. It is another object to the present invention to slightly rearrange the six strut configuration in order to approximately uncouple the mount suspension modes, thus further improving KM performance. It is yet another object of the present invention to provide kinematic mounts that achieve modal vibration tests on coupon sample mounts that yield modal damping values from 5-17% of critical damping, which are at least one to two orders of magnitude greater damping than existing designs. These and other objects are achieved by a damped instrument kinematic mount comprising instrument support means with first and second damping means wherein the damping means and instrument support means are arranged to provide the desired performance characteristics. The device, due to its generic nature can be applied to a large number of precision or optical instruments/sensors where alignment stability is important. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING FIG. 1 depicts a conventional example of a kinematic mount arrangement. FIGS. 2A-2C depict exemplary designs of conventional kinematic mounts. FIGS. 3A-3B depict cross-sections of damper designs according to two preferred embodiments of the present invention. FIG. 4 depicts an exemplary arrangement pattern for kinematic mounts. FIG. 5A illustrates a side view of a single strut according to a preferred embodiment of the present invention. FIG. 5B illustrates a cross-section of a single strut taken along line A--A in FIG. 5A. DETAILED DESCRIPTION OF THE INVENTION Kinematic mounts are used extensively as base supports for precision optical instruments and other high performance machinery. For space based applications, these mounts must fulfill two major requirements: 1) it must not adversely affect the stability of the instrument through the attachment to a less precise spacecraft structure and, 2) it must provide a strong and stable support system to the instrument during launch, and minimize the loads transmitted to the mounted instrument. The first requirement can be accomplished if the mounting system constrains only the six rigid-body modes of the instrument, without restraining the instrument in any other degree-of-freedom of motion. This is equivalent to a statically determinate mounting system, which in effect will isolate the instrument from unpredictable moment loads due to a non-ideal spacecraft interface and differences in thermal expansion rates. According to the preferred embodiments of the present inventions, the kinematic mounts have been modified by inserting vibration damping materials into the mounts. These damping materials introduce a damping mechanism into the six mount suspension modes, thus dissipating into heat and reducing the high energy disturbances to the instrument. The modifications to the kinematic mounts preserve the fundamental features, such as strength, stiffness and kinematic features. The damping mechanism may be provided at machined hinge or flexure locations of the mounts 26, 28, 32, 34, 38, 40, 42, 44. For the above mentioned six mount suspension modes, the most active portion of the mounts will occur at these flexural hinge locations. These relatively active areas can be taken advantage of by designing local dampers at these locations. This can be done in a number of ways, with two embodiments of the damper design depicted in FIGS. 3A and 3B. A first embodiment of the damper design is identified in FIG. 3A. This embodiment uses a spherical damper 46 placed around a flexure area 62. The flexure area 62 results from notching 26, 28 of the bar stock 30 used as instrument support means 24. The spherical damper 46 is composed of two partial shells 48, 50 which are concentrically arranged. The first shell 48 is placed partially over the second shell 50. The second shell 50 may be of a solid design. These two partial shells 48, 50 are connected together via a relatively soft layer of viscoelastic (VEM) damping material 52 bonded on one side to the outer surface of shell 50 and bonded on the other side to the inner surface of shell 48. Both partial shells have cylindrical extensions 54, 56 attached rigidly to the bar portion of the mount at locations 58 and 60. As the mount 46 deforms under launch loads, the mount 46 will experience elastic rotations at flexural hinge locations 62 at both ends of the bar 26, 28. Any bending action with center of rotation 62, will activate the spherical damper 46 by forcing the damping viscoelastic layer 52 to deform in shear, thus dissipating vibration energy in the form of heat. By selecting appropriate VEM 52 with the proper shear modulus, material loss factor and thickness, significant levels of damping can be designed into the suspension vibration modes of the kinematic mount 46. In one embodiment, the two partial shells 48, 50 are composed of titanium alloy. In an alternate embodiment, the two partial shells are non-metallic. At first glance, it might appear that the addition of the damper adds unwanted bending stiffness to the mount 46, and compromises proper kinematic mount action. However, this turns out not to be the case. This is because the VEM properties are frequency (and temperature) dependent in a known manner. At relatively high frequencies, where the suspension modal frequencies occur, the VEM shear modulus is relatively high causing the mount 46 to have higher bending stiffness and thus also dissipate launch loads. However, when on-orbit, where the kinematic mount action is sought for, thermal loads occur at very low loading rates or frequencies. At these low frequencies, which are typically a small fraction of a Hertz, the modulus of the VEM 52 is drastically reduced by at least a factor of 20-30 or more compared to the high frequency range. Thus, the added damper stiffness in the thermal load regime is negligible, when compared to the bending stiffness contributions from the metallic flexural hinges 62. Because of these unique frequency dependent properties of particular space qualified VEM 52, they are viable candidates in damping kinematic mounts during flight. An alternate embodiment for the damper design is depicted in FIG. 3B. This embodiment uses a cylindrical slot damper 66. The damper 66 uses a series of o-rings 68 placed within a plurality of slots 65. The o-rings 68 are space qualified high damping VEM. The slots 65 are disposed about the resulting flexural hinges 64. Instead of using a single flexural hinge 62, a number of shorter flexures are machined into the mount bar stock 64. The o-rings 68 are subjected to tensile or compressive forces, depending on the vibrational force applied to the instrument 10. Because of their light weight and strength, titanium alloy metals are commonly used to manufacture mounts 66. Whereas the spherical damper discussed above functioned by inducing shearing deformation in the VEM, this design induces compression/tension into the VEM. As far as damping performance is concerned, the damping or loss factor of the material in compression/tension is the same as in shear. It becomes apparent when studying FIG. 3B in more detail, that VEM washers could be used instead of VEM O-rings 68. In each case, we will have slightly different bending stiffness characteristics which can be tailored. A series of flat washers 68 was modeled and analyzed. The model includes a solid finite element model of a series of four aluminum (aluminum was selected for this exercise since coupons samples will be made using aluminum) flexures each 0.15 inch long and 0.3125 inch diameter, and four VEM washers 0.020 inch thick and 1.3125 inch diameter. The analysis results indicate that for a VEM washer 68, made of ISD 112 material manufactured by the 3M Company, the six suspension modes can be damped by as much as 10% of critical modal damping. A 10% damping is at least an order of magnitude increase in damping over the untreated mount. Thus, the flight induced random vibration response of the instrument 10 due to these suspension modes will roughly drop to a level of the square root of (1/10), or 0.32 of the response with the untreated mounts. This is considered a significant performance improvement over the design without the damping treatment, since the instrument is now exposed to only about one third the loads at the high energy mount modes. In the section above it was mentioned that an infinite arrangement of six restraints exist to obtain kinematic mount (KM) action. Optionally, alternative damped KM design concepts may be used according to the present invention so long as they satisfy the objectives mentioned above. Due to their very efficient stiffness to weight ratios, truss structures may be used. Alternatively, a set of three damped versions of the mount 30 configuration depicted in FIG. 2B may be used to provide a KM system. These can be arranged at the base of the instrument 10 in a variety of configurations. A classical arrangement pattern is shown in FIG. 4. In this figure, each of the six mount truss elements 74 is depicted as line elements for clarity. The damped flexure hinge designs 46, 66 discussed in the previous section (FIGS. 3A & 3B), are applicable to the present case equally well. Drawing from the design in FIG. 3B, each of the six struts 74 depicted in FIG. 4 may take the form shown in FIG. 5A. The embodiment of FIGS. 5A and 5B may use only a single strut design, since all six bars 74 may be identical to one another. This is a significant design simplification since often each of the mount elements 30 and 36 may be machined monolithically from blocks of metal. In contrast, the design depicted in FIGS. 5A and 5B involves only simple machining of standard bar stock. In a preferred embodiment, the standard bar stock may be a titanium alloy. In addition to the simple design of the mount concept described above, there are other benefits and desirable features of the proposed mounting concept. Rather than using the classical "v" configuration as shown in FIG. 4, each pair of struts 30 can be arranged in such a manner that their axial lines-of-action intersect at selected points within the instrument 10. If these three line-of-action intersection points are selected to be in the same horizontal plane as the instrument center-of-mass, then the six suspension vibration modes of the instrument 10 become approximately uncoupled. This mounting scheme constitutes a center-of-gravity mounting system, in addition to being a KM. To obtain a set of six nearly uncoupled modes is often important in applications where dynamic disturbances are inherent within the instrument. For instance, if the instrument has rotating parts which induce lateral imbalance forces near mount frequencies and passing through its center-of-mass, then the instrument with uncoupled modes will only move laterally, without rotationally disturbing the instruments' line-of-sight. Clearly, not all instruments may require this type of performance, however, if they do, the proposed mounting scheme provides this capability. From the foregoing description it will therefore be appreciated that the present invention enables the use of damped kinematic mounts to protect instruments from potentially damaging flight loads. While the invention has been described with reference to various illustrative embodiments, it will generally be understood by those skilled in the art that various changes may be made and equivalents be substituted for elements thereof without departing from the true spirit and scope of the invention.

A damped instrument kinematic mount providing novel damping features to protect instruments from damaging flight loads. The mounting scheme utilizes any number of identical strut elements to greatly reduce manufacturing complexity and costs. Improved kinematic mount performance is achieved by arranging the six strut configuration to approximately uncouple the mount suspension modes. A spherical joint damper is located at strut flexure locations and utilizes a viscoelastic damping material that deforms in shear. Alternatively, cylindrical slot mount dampers are placed at strut flexure locations. The cylindrical slot mount dampers use o-rings or washers placed within the slotted machined mount bar stock. The kinematic mounts can then be arranged in a classical truss arrangement pattern or other configuration providing desired damping characteristics.

big_patent

This is a division of application Ser. No. 849,858, filed Nov. 9, 1977, now U.S. Pat. No. 4,223,774. BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to clutch units of the oil shear type, and particularly to units having interleaved clutch plates and discs which are alternately clamped together or separated in an axial direction. The invention is directed toward a very large size clutch unit such as would be found in an aircraft catapult system for selectively winding or tensioning a nylon belt or tape which is in turn connected to a carriage secured to the aircraft to be launched or catapulted. 2. Description of the Prior Art My U.S. Pat. No. 3,696,898 issued Oct. 10, 1972 shows a clutch-brake unit in which a plurality of interleaved clutch discs and plates are provided, all of which are simultaneously actuated by a single piston. The arrangement shown in this patent would be unsatisfactory for the purpose of actuating large size clutch units which must transmit high horsepowers. Among the problems to be dealt with in the construction of large size oil shear type clutch units are the need for maximum application of forces to couple the plates and discs, the cooling requirements for the part, and most importantly, the need for minimizing residual drag. To illustrate the magnitude of residual drag problems, it should be noted that in an 85,000 horsepower clutch operating at 1200 R.P.M., the residual drag is in the order of 8-10,000 horsepower. The residual drag in the apparatus of the present invention, on the other hand, is less than 500 horsepower. BRIEF SUMMARY OF THE INVENTION It is an object of the present invention to provide a novel and improved clutch unit which overcomes the disadvantages of previously known constructions especially when applied to large size power transmission requirements. It is another object to provide an improved oil shear type clutch unit of this nature which is capable of applying strong coupling forces between the plates and discs while still maintaining high control accuracy in accordance with various input conditions. It is a further object to provide a novel and improved clutch unit of this nature which utilizes hydraulic fluid for the dual purpose of retracting the plate actuating means to reduce residual drag, and as a coolant for the clutch discs. It is also an object to provide an improved clutch unit of this character in which replacement of portions of the clutch discs may be effected without requiring complete disassembly of the unit. Briefly, the clutch unit of this invention comprises an input shaft, an output shaft, a plurality of clutch plates connected to one of said shafts, a plurality of clutch discs interleaved between said clutch plates and connected to the other shaft, and separate means for closing the gap between each clutch disc and its adjacent clutch plates, said means comprising piston and cylinder means connected to said clutch plates on opposite sides of each clutch disc, and fluid pressure control means for simultaneously supplying pressurized fluid in parallel to all of said piston and cylinder means. As will hereinafter be described, the provision of the separate piston for each of the disc segments minimizes residual drag of the unit. Auxiliary fluid pressure control meands are provided for said piston and cylinder means acting in a direction opposite to said first-mentioned fluid pressure control means for urging said clutch plates to retract from said clutch discs. Conduit means are further provided for said auxiliary fluid pressure control means leading from said piston and cylinder means to the vicinity of an adjacent clutch disc whereby said auxiliary fluid will act as a coolant. In another aspect, the clutch unit comprises an input shaft, an output shaft, a plurality of clutch discs connected to one of said shafts, a plurality of clutch plates interleaved with said discs and connected to the other shaft, said clutch discs extending outwardly from said clutch plates, each of said clutch discs comprising a plurality of arcuate segments in a circumferential arrangement, longitudinally extending supporting means for clutch disc segments, co-acting portions on said supporting means and the edges of said clutch disc segments for holding the segments in position, and removable fastener means for holding said supporting means in position, whereby removal of said fastener means will permit one or more segments to be separately removed from said clutch unit without disturbing the other segments. It is to be noted that clutch discs of the type utilized herein are traditionally manufactured through the use of relatively small size retort equipment, and that such equipment is not readily available for use in fabricating large diameter clutch components. Consequently, by utilizing relatively smaller size clutch disc segments, the conventional retort equipment may be employed. In still another aspect, the invention comprises an oil shear type clutch having interleaved clutch plates and clutch discs, each of said clutch discs comprising a plurality of arcuate segments in a circumferential arrangement, shafts for said plates and discs, and means mounting said segments on their shaft whereby said segments are separately removable. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic perspective view of a stored energy rotary drive aircraft catapult with which the present invention is associated; FIG. 2 is a block diagram showing the components of the system for controlling the clutch unit; FIG. 3 is a cross-sectional view of the servo control valve and first stage amplifier; FIG. 4 is a cross-sectional view of the second stage amplifier; FIG. 5 is a partially sectioned side elevational view of the clutch unit; FIG. 6 is a cross-sectional view in elevation taken along the line 6--6 of FIG. 5 and showing the input shaft, a bearing, and the housing; FIG. 7 is an enlarged cross-sectional view in elevation taken in the area marked 7 of FIG. 5 and showing the construction of the piston and cylinder means for a pair of clutch plates; and FIG. 8 is a cross-sectional view taken along the line 8--8 of FIG. 7 and showing the means for removably supporting the clutch disc segments. DESCRIPTION OF THE PREFERRED EMBODIMENT The clutch unit of this invention is shown generally at 11 in FIG. 1 as part of a stored energy rotary drive catapult, for example, on which would be used in an aircraft catapult system. Such a system has a prime mover such as a turbine 12 having a flywheel 13 and connected through reduction gearing 14 to drive clutch unit 11. The output shaft of drive clutch 11 is connected to a tape reel 15, the other side of this tape reel being connected to a reel brake 16 which does not form part of the present invention. The tape reel is used for selectively winding or tensioning a nylon belt or tape 17 which in turn is connected to a carriage 18 secured to the aircraft to be launched or catapulted. An advanced motor 19 is provided for returning carriage 18 to its starting position. The clutch operating system is shown schematically in FIG. 2 and comprises a servo control valve generally indicated at 20, a first stage fluid amplifier generally indicated at 21, a second stage fluid amplifier generally indicated at 22, and clutch unit 11. A reservoir 24 is shown in FIG. 2 and is adapted to supply fluid to three pumps, 25, 26 and 27 for servo control valve 20, first stage amplifier 21, and second stage amplifier 22 respectively. It has been found that three separate flows are necessary from the three separate pumps 25, 26 and 27 in view of the fact that each flow requires a different flow rate and pressure. The purpose of the servo control valve is to provide extremely accurate fluid pressure control in response to various conditions. For example, in the case of a catapult system, the torque output of the clutch must be profiled in accordance with wind and temperature conditions as well as the type of aircraft being launched. The servo valve 20 is shown more specifically in FIG. 3 and is of the same general type shown and described in my U.S. Pat. No. 3,851,742 issued Dec. 3, 1974. The servo control valve has a main body 28 and a coil housing 29. Coil leads 30 extend into main body 28 and are connected to a 12-volt d.c. coil 31 in coil housing 29. This coil controls the movement of a disc 32 which faces a valve seat 44 (hereinafter to be described) and is drawn toward said valve seat with a force depending upon the current passing to the coil. Pump 25 is connected to an inlet port 35 in main body 27, and a passage 36 extends through body 27 from this port. A passage 37 leads at right angles from passage 36 through coil 31 to disc 32, the member 38 in which passage 37 is formed extending through opening 34 and being sealingly connected thereto by an O-ring 39. The disc 32 is held by a guide 40 formed as a part of an end body 41 and disposed in a chamber 42 of coil housing 29, and an outlet port 43 is connected to this chamber. The position of disc 32 with respect to the valve seat 44 formed at the end of passage 37 thus controls the fluid flow from inlet port 35 to outlet port 43 which is connected to reservoir 23. The end of passage 36 opposite inlet port 35 is connected to a signal port 45 formed in first stage amplifier 21. A piston 46 is slidably mounted in the first stage amplifier which is made up of two body sections 47 and 48 secured together by bolts 49. Piston 46 faces an end cap 51 on the first stage amplifier and forms therewith a chamber 52. This chamber is connected with port 45 by a passage 53, a restriction 54 and recessed portions 55 on piston 46 which engage a shoulder 56 on end cap 51. A helical coil compression spring 57 is mounted in body section 48 of the first stage amplifier and engages an adjustable member 58 carried by piston 46, urging the piston against shoulder 56. A valve 59 is formed on the end of piston 46 opposite that which engages shoulder 56. This valve is tapered and co-acts with a correspondingly tapered valve seat 61 on body section 48. An inlet port 62 is formed in body section 48 of the first stage amplifier and is connected with the outlet of pump 26. A passage 63 leads from inlet port 62 to valve seat 61. According to the amount of pressure in chamber 52, piston 46 will close to a greater or lesser extent the gap between its valve 59 and valve seat 61, thus controlling the pressure of the fluid communicated via the inlet port 68. Valve seat 61 leads to a chamber 64 which in turn has a passage 65 leading to an outlet port 66 which is connected to the reservoir 23. Another passage 67 leads from inlet port 62 in the opposite direction from passage 63. Passage 67 leads to a passage 68 in the oil manifold 69 of second stage amplifier 22. Thus, the amount of pressure delivered to the signal port of the second stage amplifier will be controlled by the position of piston 46 which is in turn controlled by the position of disc 32. The construction of second stage amplifier 22 is shown in FIG. 4 which also indicates the manner in which the servo control valve and first stage amplifier are connected thereto. The second stage amplifier comprises an elongated body 71 having an inlet port 72 at its midportion and extending transversely thereto into a central chamber 73. Inlet port 72 is supplied by pump 27, and passage 73 has a pair of tapered valve seats 74 and 75 at its opposite ends and facing in opposite directions. An end member 76 is mounted in housing 71 and has a cylinder 77 formed therein. A piston 78 is slidably mounted in this cylinder and is secured to one end of a piston rod 79 slidably mounted in member 76. The other end of this piston rod carries a valve 81 which co-acts with valve seat 74 to control the amount of fluid flowing from passage 73 into a chamber 82 which surrounds a reduced portion 83 of end member 76. An outlet port 84 leads from chamber 82 to reservoir 23. A plurality of springs 85 urge valve 81 in a direction closing the space between seat 74 and valve 81. Signal port 68 is connected to a chamber 86 formed by piston 78 and oil manifold 69, and pressure in this chamber will move valve 81 along with the action of springs 85 to restrict the passage to valve seat 74. A valve 87 is disposed adjacent valve seat 75 and is guided for axial movement by an end member 88 in body 71. The valve is held normally closed by a plurality of compression springs 89 disposed in bores within member 88. However, when the pressure within chamber 73 reaches a predetermined magnitude, valve 87 will be lifted from seat 75 to permit fluid to pass through the valve seat. Valve seat 75 leads to a chamber 91 which has an outlet port 92 connected to an inlet passage 93 (FIG. 5) for the clutch unit. Passage 93 constitutes the main fluid supply connection for the clutch unit and, as will be later described, supplies fluid which simultaneously actuates all the clutch plate piston and cylinder means in a coupling direction. An axial bore 94 in valve 87 leads to a chamber 95 within end member 88. An outlet port 96 leads from chamber 95 to a passage 97 in the clutch unit (FIG. 5). Passage 97 constitutes an auxiliary fluid supply for the clutch unit, the fluid in this passage exerting constant retracting pressure on the clutch plate piston and cylinder means as well as serving a cooling function for the clutch discs. A tapered seat 98 is provided in the end passage 94 which co-acts with a complementary adjustable valve 99. The position of valve 99 may be preselected to determine the flow rate and pressure to the auxiliary passage 97. A side passage 101 leads from passage 94 to a chamber 102 on the side of valve 87 opposite that which faces chamber 73. The pressure in chamber 102 aids springs 89, but the area on which the pressure in chamber 102 acts is less than that on which the fluid in chamber 73 acts in a valve opening direction. FIGS. 5-8 show the construction of clutch unit 11. The clutch unit comprises a base 103, a lower housing 104 (which is preferably formed integrally with base 103), and a domed upper housing 105. An input shaft 106 extends through an end plate 107 at one end of the housing and an output shaft 108 extends through an end plate 109 at the other end. Input shaft 106 is supported by a hydrodynamic bearing 110 and by a hydrostatic bearing 162 hereinafter to be described. Output shaft 108 is rotatably supported by hydrostatic bearings 111 and 112 which have separate oil supplies. A housing 113 surrounds bearing 110 so as to journal support the adjacent end of the input shaft 106. The housing 113 defines an annular chamber 114 which is supplied by main fluid inlet passage 93. A second and smaller annular chamber 115 in housing 113 is supplied by auxiliary fluid passage 97. It should be noted that the bearing 110 acts as a rotary fluid seal between the chambers 114 and 115. A radially outwardly extending portion 116 is formed on the end of input shaft 106 within housing 104, 105 and has a plurality of radial passages 117. An annular member 118 is disposed within a bore in shaft 106 and extends between chamber 114 and passages 117. A plurality of inwardly extending radial passages 119 extend from annular chamber 114 and are connected to the axially extending chamber 121 formed by member 118 and shaft 106. Thus, the main fluid flow will be led radially outwardly by passages 117. It should be noted that input shaft 106 with portions 116, members 122 and 161 (hereinafter described), form a unitized input shaft assembly. An annular member 122 is provided and extends axially from the outer edge of input shaft portion 116. A plurality of circumferentially spaced axially extending passages 123 are formed in member 122. One end of each passage 123 is connected to a corresponding radial passage 117 by a short connecting passage 124. A plurality of annular clutch plate assemblies generally indicated at 125 are secured in axially adjacent relation to the outside of member 122. The assemblies are held in position by key 126 on member 122 so as to prevent relative rotation, and are held against endwise movement by annular members 127 and 128 carried by the ends of member 122. The construction of each assembly 125 is shown in detail in FIGS. 7 and 8. The clutch assembly comprises an inner member 129 mounted on key 126 and having fitting spacers 131 at opposite ends which maintain proper spacing with respect to the adjacent assemblies 125. One portion of member 129 is provided with splines 132. A first annular clutch plate 133 of L-shaped cross section has splines 134 interfitting with splines 132. The main radially extending portion of clutch plate 133 has a heat treated surface 135 engageable with one side 136 of a series of segmented annular clutch discs 137 which are described in detail below. A piston 138 is threadably mounted at 139 on the portion of clutch plate 133 which carries splines 132. The piston is slidably mounted within a cylinder 141 which has a first radially extending portion 142 slidably connected by splines 143 to splines 132. A second axially extending portion 144 of member 142 has a second annular clutch plate 145 secured thereto by a plurality of circumferentially spaced bolts 146. Clutch plate 145 has a heat-treated surface 147 engageable with the other side 148 of clutch disc segments 137. Fluid passage means are provided for leading the pressurized fluid from passage 123 to the chamber 149 which is formed between clutch plate 145 and piston 138. A seal 151 is carried by the axially extending portion of clutch plate 133 and engages a facing surface on clutch plate 145, and a seal 152 carried by piston 138 engages cylinder 141, these two seals forming the closed chamber 149. The passage means comprises a radial passage 153 leading from passage 123 to a passage 154 in member 129. A passage 155 in the axially extending portion of clutch plate 133 leads from passage 154 to chamber 149. Passages 157 are formed in the piston 138 to provide fluid flow between passage 155 and the interior of the chamber 149. A plurality of control orifices 158 extend through the axially extending portion of clutch plate 133 to the space 159 in the vicinity of clutch disc segments 137. These control orifices lead from passage 154 and are for cooling fluid to the clutch disc segments. A radial plate 160 is secured to the inside of member 122, and a bearing support section 161 is secured to the central portion of plate 160 and carries the aforementioned hydrostatic bearing 162. This bearing permits the extension 163 secured to the inner end of output shaft 108 to journal support section 161 and hence rotatably support inner end of the shaft 106. Annular chamber 115 for the auxiliary fluid feeds a radially inwardly extending passage 164 in shaft 106 which leads to an axial passage 165. The auxiliary fluid will flow from this passage through a central passage 166 in member 118 to radial slots 167. This passage leads to an annular chamber 168 formed between an end flange member 169 mounted on member 118, and a chamber on shaft portion 116. Flange 169 is secured by bolts 170 to shaft portion 116. Passages 171 lead from chamber 168 to radial passages 172 in shaft portion 116 between passages 117. Passages 172 lead to a plurality of axial passages 173 disposed between passages 123 in member 122. A radial passage 174 leads from each passage 173 to an annular chamber 175 in each member 129. Chamber 175 is located alongside chamber 154 but is of somewhat small cross-sectional area. One or more restricted passages 176 lead from chamber 175 to cylinder chamber 141. Pressure in chamber 141 caused by the centrifugal force of the oil within the unit will tend to move clutch plates 133 and 145 away from clutch disc segments 137. The auxiliary fluid will thus serve the function of constantly and positively urging retraction of the clutch plates, so that when pressure is relieved in chamber 149, the clutch plates will be entirely separate from the clutch discs to reduce residual drag to a minimum. A passageway 177 leads from each chamber 141 through member 142 to an extension 178 loosely interfitting with a recess 179 in the adjacent clutch plate 133. A passage 180 leads from chamber 179 through clutch plate 133 to the space 159 surrounding disc segments 137. The auxiliary fluid will thus serve the additional function of cooling the clutch discs both during the operation of the unit and when the clutch is disengaged. An outwardly radial portion 181 is formed on output shaft 108 between bearings 112 and 162. Portion 181 is located at one end of the stack of clutch plates and discs. A member 183 is disposed at the other end of the stack and extends radially inwardly, the inner end 184 of this member extending axially and being supported by bearings 111. The series of segmented clutch discs 137 are mounted in such a manner as to permit the easy removal and replacement of individual segments without the necessity of disassembling the entire mechanism. This means comprises recessed portions 185 on the opposite edges of each clutch disc segment 137 which interfit with bushings 192. These bushings have shoulders 196 which engage the sides of the clutch disc segments. The spacing between shoulders 196 at the opposite ends of the bushings 192 will allow slight axial play of the clutch disc as seen in FIG. 7. The upper surfaces 197 of bushings 192 are flat so as to be engageable by keys 191 and the portions 201 of shoulders 196 opposite surfaces 197 are also flat. Keys 191 are slidable into enlarged portions 188 on rings 186 and 187 which surround the clutch discs, these enlarged portions having slots 189 to receive members 191. Each pair of rings 186 and 187 is connected by bridges 182 between sets of clutch disc segments. There are thus a plurality of integral members in tandem, each comprising a ring 186, a ring 187, and connecting bridges 182. The facing rings 186 and 187 between adjacent integral members clamp bushings 192 between them. The clamping is accomplished by studs 193 with nuts 194 and 195, the nuts being disposed between bridges 182. The studs at the ends of the stack are secured to members 181 and 183 as seen in FIG. 5. Members 191 are also held between these rings and are further secured against circumferential movement by locking bolts 198 passing through members 199 which are secured to rings 186 or 187 and threaded into members 191. It will thus be seen that removal and replacement of any one or more of clutch disc segments 137 may be easily affected without the necessity of disassembling the entire unti. It will merely be necessary to unscrew the desired bolts 198, slip out members 191 from the raised portions 188 of rings 186 and 187 and rotate members 192 on their own axes until flat portions 197 and 201 face one another, i.e., are opposite the recessed portions 185 of the clutch disc segments 137. One may then slip out the clutch disc segment(s) since lips 196 will no longer be blocking such removal. After the new clutch disc segment(s) are inserted, members 192 may be rotated to their original position so that their lips 196 hold the new clutch segment(s) in place and members 191 slipped into position and held in place by bolts 198. In operation of the entire system, the input signal to solenoid 31 of servo control valve 20 will cause this valve to control the signal to first stage fluid amplifier 21. This in turn will control the signal to second stage fluid amplifier 22, thus determining the flow rate and fluid pressure of both the main and auxiliary supplies to clutch 11. The main fluid supply will be fed to chambers 149 of piston and cylinder means 138, 141 of all the clutch assemblies 125. Thus, clutch plates 133 and 145 will approach the clutch disc segments 137 disposed between them to a greater or lesser extend depending upon the pressure supplied to chambers 149. Since the pressure is simultaneously applied in parallel to all chambers 149, the separate piston and cylinder means for each set of clutch disc segments and clutch plates will impose full force on all portions of the assembly, permitting the transmission of maximum torque. At the same time fluid will be flowing through the auxiliary passages and out through passages 180 to the space 159 adjacent the clutch disc segments, while the main fluid supply will pass through orifices 158 to maintain the cooling effect on the clutch disc segments. Since the auxiliary oil supply maintains a pressure in chambers 141 in accordance with the rotational speed of the unit (magnitude of the centrifugal force acting on the oil) the piston and cylinder means will be caused to positively retract, separating clutch plates 133 and 145 from the clutch disc segments and reducing to a minimum the residual drag. It will be seen from the foregoing that the present invention provides a new and improved clutch unit which has a number of extremely important features not shown in the prior art. Among the more important of these features is highly improved cooling through better oil flow control, and a minimum amount of disc friction on the disc stack which provides for improved torque control. Another extremely important feature of the present invention is the segmental disc arrangement which minimizes the deleterious effects of heat on the discs. Additionally, convenient inspections of the disc segments is achieved without requiring total "tear-down" of the unit. Another feature of the present invention resides in the fact that retraction of the discs is achieved via the centrifugal force of the oil which obviates the need for retraction springs which might tend to malfunction in clutch units of the size and speed range of the applicant's invention. More importantly, however, the present invention provides a new and improved clutch unit which minimizes residual drag which is extremely important in clutch units of the capacity, i.e., 85,000 h.p., of the present invention. While it will be apparent that the preferred embodiment of the invention disclosed is well calculated to fulfill the objects above stated, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope or fair meaning of the subjoined claims.

A clutch unit especially adapted for accurately controlling the transmission of high rotary forces with minimum residual drag. A servo control valve supplied with hydraulic fluid by a pump controls a first stage fluid amplifier supplied by a separate pump, this amplifier in turn controlling a second stage amplifier supplied by a third pump. The second stage amplifier supplies main and auxiliary inlet ports of the clutch unit. The oil shear type clutch has a plurality of interleaved plates and discs. Separate piston and cylinder means is provided for actuating the plates for each clutch disc by means of the main fluid supply, the pressure of which is varied in accordance with input signals to the servo control valve. The auxiliary supply to the clutch acts both to retract the piston and cylinder means, thus separating the plates and discs with a minimum of residual drag, and as a cooling medium. The clutch discs are segmented so as to permit economical fabrication in spite of the large size of the clutch, with the disc segments being mounted as to permit convenient replacement without requiring complete disassembly of the unit.

big_patent

RELATED APPLICATIONS [0001] The application is a continuation application of prior U.S. application Ser. No. 12/568,034, filed on Sep. 28, 2009, and which claims the benefit of: (1) U.S. Provisional Application No. 61/173,355, which was filed on Apr. 28, 2009, (2) U.S. Provisional Application No. 61/166,260, which was filed on Apr. 3, 2009, and (3) U.S. Provisional Application No. 61/100,295, which was filed on Sep. 26, 2008. Each of these disclosures are herein incorporated by reference in their entirety. BACKGROUND [0002] Internal combustion engines contain multiple cylinders. Exhaust gas is generated when a fuel and air mixture is ignited and expanded within a cylinder to drive a piston. The exhaust gas is typically vented from the cylinders through an exhaust stroke to the atmosphere. The exhausted gas typically has a very high temperature when leaving the cylinders. In some proposed systems, the exhaust gas is delivered to a second cylinder for further expansion. [0003] Some internal combustion engines have injected water into the same cylinder performing combustion with fuel and air intake. [0004] There has also been a proposal for a combined engine that has a combustion cylinder mounted upstream of an expansion cylinder. The expansion cylinder receives hot exhaust gas from the combustion cylinder, and also receives a source of water that is expanded into steam by the hot exhaust gas to create further drive for a common crankshaft. [0005] While this proposed system has good potential, there are many improvements that would make the system more practical. SUMMARY [0006] In features of this invention, downstream expansion cylinders are associated with a combustion cylinder to provide an overall surface area and volumetric displacement of expansion cylinders sufficient to lower the temperature of fluids associated with the combined engine to such an extent that a radiator can be eliminated in an associated vehicle, or other system. [0007] In a separate feature, a catalytic material is placed on surfaces which will “see” the hot exhaust gases such that catalytic conversion of impurities in the gases can be achieved within the engine itself. [0008] In yet another feature, water is recovered from a system having both a water injection expansion cylinder, and a combustion cylinder, and the recovered water is re-used for the expansion. [0009] In yet another feature, gearing is provided between an expansion cylinder and a combustion cylinder such that the output of the combined engine is optimized, and the two cylinders do not drive the crankshaft in a one-to-one fashion. BRIEF DESCRIPTION OF THE DRAWINGS [0010] FIG. 1 schematically shows a first embodiment engine. [0011] FIG. 2 is a flowchart of a basic system incorporating this invention. [0012] FIG. 3 shows a second embodiment system. [0013] FIG. 4 shows another potential embodiment. [0014] FIG. 5 shows yet another embodiment. [0015] FIG. 6 shows yet another embodiment. [0016] FIG. 7 shows yet another embodiment. [0017] FIG. 8 graphically shows the input versus output for exemplary systems. [0018] FIG. 9 shows a water cooling system incorporated into this invention. [0019] FIG. 10 shows another embodiment of the water cooling system. [0020] FIG. 11 shows a water recovery system. [0021] FIG. 12 shows a catalytic conversion system. DETAILED DESCRIPTION [0022] An engine 20 is illustrated in FIG. 1 , and incorporates combustion cylinders 32 and 34 , which are mounted adjacent to an expansion cylinder 33 . Each of the cylinders include pistons 50 , which are driven to drive a common crankshaft 52 . Although the cylinders are shown in side-by-side relationship, in practice, they will be inline such that the common crankshaft 52 is driven by each of the pistons 50 . Of course, other configurations can be used. [0023] The cylinders 32 and 34 are combustion cylinders and are shown having spark plugs 44 . However, other combustion cylinders which do not require spark plugs would also benefit from the teachings of this application. [0024] As shown, intake valves 40 control the flow of air and fuel into the cylinders 32 , 34 , in some engine types, such as Diesel, the fuel may be directly injected into the cylinders. The combined air and fuel is compressed, ignited, and exhausted through exhaust valves 42 into an associated exhaust line 46 . The cylinders 32 and 34 may be four-stroke cylinders, and will operate as known, at least as described to this point. [0025] Inlet valves 48 on the expansion cylinder 33 alternately operate in sync with the alternating operation of valves 42 and receive the hot, high pressure exhaust from the exhaust lines 46 . The gases at least partially drive the larger displacement piston 50 associated with the expansion cylinder 33 in a two-stroke fashion. As known, the cylinders 32 and 34 will be out of phase by 360°. Cylinder 33 has a final exhaust valve not shown. [0026] A water injection system 70 takes water from a source of water 71 and injects it into the engine at any one of several possible locations. As shown, the water may be injected through line 72 into the exhaust line 46 . Water may be injected through line 74 to the top of the cylinder of the expansion cylinder 33 . The water may be injected as shown at 76 into the top of cylinders 32 , 34 . If injected into the cylinders 32 and 34 , it is preferred that the water be injected late in an exhaust cycle. [0027] The water injection and metering can be performed in much the same way as high pressure fuel injection is commonly performed in a diesel engine, for example. The injection of water is estimated to be at a rate of 1 to 2 times the rate of fuel consumption for a gasoline engine. The water can be injected into the expansion cylinder 33 head at the time exhaust gases are being communicated to the expansion cylinder 33 . Owing to a finite thermal absorption and vaporization delay for the heat of the ignition to vaporize the injected water, it may be beneficial in some cases to move the injection of the water forward in the process, into the exhaust passage 46 , or into one of the cylinders as described above at 76 . In the case of injecting the water into one of the combustion cylinders 32 or 34 , this should occur at a mature point of the power-stroke, 160 degrees-175 degrees, past top dead center, for example. [0028] Valves V are shown for controlling the flow of the injection of the water, and may be controlled by an overall engine control, in a manner that would be apparent to a worker of skill in this art. [0029] While cam shafts are shown for controlling the operation of the several cylinder valves, other means of valve timing, such as electronic valve controls may be utilized. [0030] Fuel and air fed combustion cylinders 32 and 34 may fire nominally at 0 degrees and 360 degrees of rotation respectively. The cylinders 32 , 34 alternate intake and power strokes while the expansion cylinder 33 executes an exhaust stroke. During the exhaust stroke, gases exit the expansion cylinder through a valve, not shown. Each cylinder 32 , 34 contributes torque to a crankshaft 52 through the power-stroke. The combustion cylinders 32 , 34 alternate compression and exhaust strokes while the second cylinder 33 is executing a power stroke. In the power stroke, the piston 50 in the expansion cylinder is driven by expansion of the steam and exhaust gas. The expansion cylinder 33 expands the exhausted gas of the cylinder 32 beginning nominally at 180 degrees of rotation and then, after completing an exhaust stroke, the cylinder 33 alternately further expands the emission from the cylinder 34 beginning nominally at 540 degrees of rotation, in a two-stroke fashion. [0031] In one example, displacement of the expansion cylinder 33 is four times that of the cylinders 32 or 34 (the displacements of the cylinder 32 and cylinder 34 may be nominally the same). Accordingly, the second cylinder 33 contributes significant positive torque to the crankshaft 52 . [0032] Oil pans 60 associated with the combustion cylinders 32 and 34 are shown. The sump 62 of the expansion cylinder may be sealed from the oil pans 60 , and their combustion cylinders 32 and 34 , such that water can collect, as will be described below. [0033] FIG. 2 is a flowchart which briefly describes the above-described system. First, an exhaust gas is produced in a combustion cylinder. This exhaust gas is expanded along with water via a water injection process. The expanded gas creates a pressure front which drives the expansion cylinder piston. The expanded gas is substantially cooled before discharge. Thermal transfer between cylinders maintains the working temperature of the first cylinder. [0034] FIG. 3 shows a top down view of an embodiment 100 with combustion cylinders 132 associated with an expansion cylinder 133 . An exhaust passage 146 connects cylinders 132 to cylinder 133 . Additional downstream expansion cylinders 102 are provided, to provide a multi-stage cascade. As shown, the exhaust 104 from the expansion cylinder 133 delivers expanded exhaust gas into the cylinders 102 . [0035] In general, the use of the several expansion cylinders provides that the total surface area of expansion cylinders is sufficiently large that all, or the great majority, of the generated heat and energy can be recaptured prior to being exhausted to atmosphere. In this manner, the invention may allow the elimination of the radiator. [0036] The pistons of the outer expansion cylinders 102 can have the same rotational phase as the four-stroke cylinders 132 , respectively, and could be 180 degrees out of phase with the central two-stroke expansion cylinder 133 . In this example, the need for ever larger displacement through a cascade is provided by having the combined displacement of the outer cylinders 102 be substantially greater than the displacement of the central cylinder 133 , while the interior configuration may operate as previously described. [0037] The example outer cylinders 102 , may have bores that are larger than the central cylinder 133 by a factor of √{square root over (2)}, causing a combined displacement four times larger than the first cascade in the central cylinder 133 . [0038] In one example, two outer cylinders 102 receive the exhausted gas. In other examples, cascading continues from cylinder 133 to a single downstream cylinder. The direction and number of cylinders receiving the exhaust is not limited. It is desirable that each downstream, or cascaded, cylinder has larger displacement than the cylinder providing exhaust gases. [0039] Water injection can occur through a water injection line 108 which is shown injecting water into the first stage expansion cylinder at 107 , and the second stage expansion cylinders 102 at 106 . As will be described below, the several stage cascading as disclosed in the FIG. 3 embodiment allows the exhaust gas and water to be lowered to a very low temperature, and for a great majority of the potential energy generated by the combustion process to be captured as useful energy, rather than lost as wasted energy. [0040] As seen in FIG. 4 , four-stroke combustion cylinder 202 drives a crankshaft 280 , and a two-stroke expansion cylinder 204 that is powered by exhaust and water as described above, drives a shaft 279 . An intermediate two-to-one gear reduction 206 may be a planetary transmission. The gear reduction 206 may be any type of coaxial gear reduction. One example would be a complex planetary gearing system, including more than one planetary gear set to eventually provide a 2:1 reduction, however, other gear reductions can be utilized. [0041] The crankshafts of the two cylinders 202 , 204 are mechanically synchronized in this embodiment through gear reduction 206 , such that the 360 degree operation of cylinder 204 is effectively expanded to 720 degrees to match the operation of four-stroke cylinder 202 . The example arrangement has the heavier reciprocating mass of the two-stroke, secondary power-stroke expansion cylinder 204 now reciprocating at half speed of the lighter, but faster, fuel and air fed four-stroke cylinder 202 . The example arrangement has appreciable opportunity for additional thermal-to-mechanical energy extraction through a single cascade. [0042] As shown in FIG. 5 , an alternative system may use a dual gearing 208 and 210 that achieves the two-to-one gear reduction from the expansion cylinder crankshaft 212 to the crankshaft 214 . This may allow the larger displacement requirement of expansion cylinder 204 to be achieved by a longer stroke or a combination of a larger bore and a larger stroke. [0043] The FIG. 4 or 5 arrangements can be used in combined multiple groupings. Also, water injection would preferably be used with these embodiments. [0044] Referring to FIG. 6 , two two-stroke secondary power-stroke expansion cylinders 502 can be coupled to one four-stroke combustion cylinder 504 in various different formations. In such formations, the four-stroke cylinder 504 supplies the exhausted gas required for secondary expansion alternately to the two two-stroke secondary power-stroke expansion cylinders 502 . In general, the expansion cylinders 502 are driven such that they operate at one-fourth the speed of the piston for the combustion cylinder 504 , and are out of phase with each other. A gear reduction 581 is shown schematically connecting their crank portions 580 . Typically, the three crank portions will be non-coaxial, although this is not a limitation on this portion of the inventive concepts. [0045] For each two-stroke expansion cylinder 502 , there are four quarter-exhaust strokes and four quarter-power strokes for each one thousand fourteen hundred forty degree cycle, or two four-stroke cycles. The first two-stroke cylinder 502 is offset from the second two-stroke cylinder 502 , such that when one is in an exhaust stroke, the other is in a power stroke. This allows the four-stroke 504 to feed one two-stroke at a time. [0046] Again, a water supply source 535 may inject water through a line 537 into an exhaust line 19 connecting the single combustion cylinder 504 to each of the expansion cylinders 502 . Of course, as with the earlier embodiments, any number of other locations for water injection may also be utilized. [0047] Again, an oil pan 583 may be maintained separate from water sumps 579 . [0048] An embodiment 700 is illustrated in FIG. 7 . Combustion cylinders 706 generate hot exhaust gas which is passed downstream to a first expansion cylinders 704 , and then to second expansion cylinders 702 . Each expansion cylinder 704 and 702 has a progressively greater displacement and effective surface area compared to the combustion chambers 706 . As shown, gearing 714 drives gear 712 to achieve a first gear reduction, and gear 712 drives a second gear 713 . The gear reduction between gears 714 and 712 is selected such that there is a 2:1 step-down. Gears 712 and 713 provide a 1:1 drive arrangement. [0049] The operation of the system may generally be as described above. Again, water injection is shown schematically through a source 710 into the expansion cylinder 702 and 704 . Again, water pans 703 may be maintained separate from oil pan 701 . However, here oil pan 701 services both combustion cylinders 706 and hot first expansion cylinders 704 while only the second, and final in this example, expansion cylinders 703 are cool enough to be serviced by water pans 703 . [0050] In other examples, N-two-stroke expansion cylinders can be coupled to M positioned four-stroke cylinders to create multiple cascades. Here, N and M are arbitrary numbers greater than or equal to 1. [0051] In a similar example, one four-stroke cylinder could feed N-number of two-stroke, secondary-power-stroke expansion cylinders, where N is an arbitrary but generally even number. This creates an adaptable system configuration where the engine wastes little to no heat and the final exhaust temperature is brought to an exceptionally low value. Therefore, the only system energy exit is through the performance of mechanical work. This may allow the elimination of the radiator for an associated vehicle. [0052] High-temperature, water-lubricated polymeric materials may be used in critical places within the construction of the second cascade, such as the outer cylinders 702 . For example, the second cascade can have a dense, Teflon-like coating on the interior of the cylinder wall. The type of coating is not limited here. The connecting rod bearings similarly may use dense Teflon for bearing material, although similarly, not limited. The second cascade may be intentionally driven beyond the condensation point, such that water lubrication is available, as water condensation is captured within the engine for re-use. The heat loss by the final exhaust can be managed in this manner down to a negligible level. [0053] FIG. 8 shows a schematic summary of the overall operation of the several above disclosed embodiments. Air and fuel is brought into the system and combusted. Thermal insulation is preferably provided about the engine such that there is minimal heat loss to the environment from the engine. The energy output in a typical engine includes mechanical work, such as driving a crankshaft. The inventive systems are designed to maximize this output. [0054] The prior art systems typically lose heat to a radiator. The inventive systems attempt to minimize any heat to a radiator, and in fact to eliminate any need for a radiator, as will be explained below. [0055] Prior systems lose heat to the exhaust. The inventive systems aim to reduce the temperature of the exhaust to such an extent that there will be little or no heat loss at this location. The same is true with heat loss to convection. [0056] FIG. 9 shows an embodiment 900 of a water cooling system which may be maintained as a closed circuit, and separate from the water injection. In the water cooling system 900 , cascade or expansion cylinders 902 are adjacent to a combustion cylinder 904 . A water jacket 906 surrounds each of the cylinders. As can be appreciated, fuel, air and water injection lines, consistent with the above-described embodiments, would also extend through the water jacket in actual embodiments. A return line 908 returns water from the water jacket 906 through a flow control valve 910 , and to a water pump 912 which recirculates the water. The pump 912 is arranged such that it pulls the water from the vicinity of the combustion cylinder 904 , over the expansion cylinders 902 . The heat which is captured in the water by cooling a combustion cylinder 904 is partially captured to heat the expansion cylinders 902 . An optional heat exchanger 951 may be included which utilizes remaining heat in the return line 908 to heat water in the water injection line 950 heading for the expansion cylinders. However, this heat exchanger is optional, and need not be utilized. [0057] The main requirement for the cooling water jacket to cool the combustion cylinders, and then heat the expansion cylinders, is that the temperature of the cascade or expansion cylinders needs to be lower than the working temperature of the liquid coolant. This requirement can be facilitated by increasing the operating pressure, and therefore temperature, of the liquid coolant system. A temperature sensor 914 can be set such that it will send a signal to a control 916 to allow higher temperatures if such are desirable. While water may be used as the cooling fluid, any number of other coolants may be utilized. [0058] The temperature sensor 914 may provide information back to the control 916 which controls the water valve 910 to ensure adequate water supply to maintain the temperatures as desired. [0059] In addition, the control 916 may be an ignition control input which can control the timing of the ignition for the combustion cylinder 904 . In a standard engine, it would not be desirable to slow ignition timing based upon undue temperatures in the system, as this will simply reduce the overall produced useful energy. However, given that the present invention captures a much greater percentage of the useful energy, slowing of ignition timing can be utilized while still capturing sufficient power through the subsequent cascades. Thus, the control 916 may be programmed with an algorithm that will identify an undesirably high temperature at the temperature sensor 914 , and slow ignition timing. In this manner, the overall system can be more likely to capture a greater percentage of the useful energy created by combustion. [0060] In general, the control 916 can modulate the ignition timing to achieve tight control over the temperature of the combustion cylinder. A sensed over-temperature condition can be rectified by retarding the ignition timing by one to twenty-five degrees of crank rotation, for example. The exact amount may depend on the size and abruptness of the overall temperature condition. This will transfer some of the heat load to the expansion cylinders, where it can contribute to useful work. This retardation of ignition timing will also reduce the peak temperature and pressure for the benefit of reduction of pollutant generation. [0061] FIG. 10 shows another embodiment 920 wherein the expansion cylinders 902 are positioned to be separated by a thin wall 922 from the combustion cylinder 904 . All of the cylinders may be formed in a single block 921 . This embodiment may be a passive transfer system that does not include a pump. The liquid jacket 919 surrounding the block 921 may be a sealed container containing any vapor or liquid fluid having good heat transfer properties. [0062] Any number of other ways of transferring heat from the combustion chambers to the expansion chambers may be incorporated into this invention. [0063] With either of the FIGS. 9 and 10 embodiments, the very hot combustion cylinder 904 transfers heat energy to the cascade cylinders 902 . The cascade cylinders 902 benefit from this additional heat, as it increases the temperature of the injected water environment to produce additional steam, and allows the recapture of this heat energy. [0064] By capturing and transferring the heat in this manner, the system is able to reduce the exhaust gas and water from the most downstream cascade cylinder to such an extent that no radiator may be necessary. [0065] FIG. 11 shows a water recovery system 930 . When utilized in a system, and in particular in a mobile vehicle system, the source of water to be injected must be contained within a tank 936 associated with the vehicle. The system 930 has a cylinder 932 provided with a piston 933 driven to expand from exhaust and water expansion, as are found in any of the embodiments described above. An exhaust 938 of this system passes through a water scrubber or water trap 940 which returns water through a line 941 , and passes exhaust gases downstream through a line 943 . More than one phase of water scrubbing may be provided. Eventually, the exhaust gas may reach a muffler 942 . Muffler 942 may be provided with yet another scrubber 944 which passes the final exhaust gas through line 945 to atmosphere, and returns water through yet another water return line 941 to an overall water return line 952 . Scrubber 944 may be included within the muffler housing or attached downstream. [0066] The piston 933 is provided with piston seals 948 which may provide a loose seal with an internal surface 950 of the expansion cylinder 932 . The amount of “clearance” is exaggerated in this Figure to show the fact of the clearance. The crankcase 946 for the expansion cylinder may be separated from oil such that the expansion cylinder components are lubricated only by this water. The water-containing crankcase may be similar to the case 62 in FIG. 1 , 579 in FIG. 6 , 703 in FIG. 7 or any other arrangement. The use of the loose fit will ensure that a good deal of steam which has been expanded to the point of condensation in the cylinder 932 will fall to the crankcase 946 , and be returned through water return line 952 to the water tank 936 . A pump 937 may drive the water to the injection line 934 back into the cylinder 932 . [0067] The recovery of the water from the crankcase 946 may be only necessary on the most downstream expansion cylinder, however, it can optionally be utilized on more expansion cylinders than simply the most downstream. A water scrubber 939 is shown on the line leading from the crankcase 946 , and may remove an exhaust gas 929 , similar to the above-described embodiment. [0068] The water scrubbers may be known water traps, and in particular may be chilled or cold water traps of known design. Further, the crankcase drain line can be combined into the exhaust line 938 such that a single set of water scrubbers may be utilized to achieve the above-described features. [0069] By having this detailed water recovery system, the present invention ensures that the source of water will be largely recycled, and that an unduly large water tank will not be necessary. [0070] Across the embodiments, expansion cylinders may be provided in sufficient numbers, such that the final exhaust may be brought to a low temperature, say below 500° F., and in a preferred embodiment, at or below 212° F. When surrounded with high levels of an external insulation, this low temperature exhaust becomes almost entirely the sole source of thermal efficiency loss in steady-state operation. The frictional “loss” of internal moving components also becomes captured within the system so as to be either converted as part of the useful mechanical output or to otherwise be a component of this modest final exhaust emission. These engines may achieve steady-state thermal-to-mechanical efficiencies that are in the range of 94-96%. [0071] Steady-state operation may be characterized by the following rough thermal budget. In a current engine, say a radiator would account for 25% of the thermal budget, while in the described examples accounting for essentially 0%. In a current engine, conduction/convection might account for 25% of the thermal budget whereas in the described examples accounting could be approximately 1-2% of the thermal budget. In a current engine, exhaust may account for 25% of the thermal budget whereas in the described examples may account for approximately 2-3% of the thermal budget. Further, in a current engine, mechanical extraction may account for 25% of the thermal budget where as in the described examples might account for approximately 95% of the thermal budget. [0072] It is believed that there could be back pressure due to the injection of the exhaust gas that could complicate the breathing induction of the combustion cylinders. By injecting water into a cascade cylinder head space after the exhaust gas communication is complete (as an example at the 50% cut-off point for a 2:1 crank synchronization; at the 25% cut-off point for a 4:1 crank synchronization, there will be less back pressure for the exhaust cycle to work into. As another example, should there be a 8:1 speed reduction on the cranks, the above can occur at the 12.5% cut-off point. This will improve the breathing of the combustion cylinder to improve power density, while still allowing the establishment of a steam vaporization pressure front. [0073] Other ways of addressing this breathing concern can be utilized. As an example, the combustion four-stroke cylinder can be RAM charged or super-charged. The combustion cylinder can be of a particularly long stroke, as in a diesel cycle. The combustion cylinder can employ at Atkinson cycle, resulting in a very low cylinder pressure by the end of its power-stroke. The displacement ratio of the expansion cylinder to the combustion cylinder can be designed to be higher than described above. The combustion cylinder can be replaced with a split-cycle pair of cylinders, as has been proposed by Scuderi Motors. Water can be injected into the cascade cylinder head space after the exhaust communication is complete, as described above. Any of these methods of simplifying the breathing/back pressure issue can be utilized. [0074] Referring to FIG. 12 , in one example, components have their surface materials chosen so as to catalyze certain desirable reactions for the benefit of reduced exhaust emissions. A surface within a cylinder assembly could include an inner lining 611 made of a particular surface material designed to have the same catalyzation effect as a catalytic converter. In one embodiment, the cylinder is an expansion cylinder, and more preferably, plural expansion cylinders such as are described above. The surface materials may include but are not limited to: platinum, palladium, rhodium, cerium, iron, and manganese. This example takes advantage of both the enhanced residence time as well as the enhanced surface area, as both increase with an increase in cascaded cylinders, to catalyze reactions that are presently catalyzed in a separate external catalytic converter subsequently eliminating or reducing the need for the converter. As shown in FIG. 12 , a first cylinder 604 is associated with a downstream cylinder 606 , which is larger. Pistons 608 move within the cylinders 604 and 606 . Cylinder head 619 receives valves 617 . An exhaust connection 610 connects the two. The lining material 611 can be formed on any, or all, of the interior of the cylinders, the pistons, and the cylinder heads, the valves and in the exhaust passage 610 . The catalytic materials can be used on any surface, e.g., fluid flow paths, etc., that will “see” the hot exhaust gas. [0075] In another example, different surface materials for internal environments become required as the final exhaust emission is likely to be much cooler than presently-in-use four-stroke engines, and possibly much lower than desirable for best catalytic reaction kinetics. [0076] Generally, surfaces exposed to the hot gaseous fluid flow may have thermal insulation on the outside of the arrangement, or hot interior-surfaces and structural components may be made of thermally low conductive material. Another alternative would be to maximize heat loss prevention and use a low conductive material that is additionally thermally insulated on the outside. For example, the piston tops have substantial surface area exposed to hot gases, while their bottoms are exposed to crankcase oil. The heat-of-combustion to the displacement volume above the piston top may be confined for thermal-to-mechanical extraction and to avoid heating the crankcase oil. Therefore piston tops made of, for example, a thermally dead ceramic, or ones with a lightweight, crankcase-compatible insulation on the underside, or both, may be used. Another example would be pistons made of normal material, clad bonded with a thermally dead ceramic top surface. Similar concepts could be applied to the valves and valve tops, the hot gaseous-exposed interior-surface of the cylinder-head, the intake passages and exhaust passages from one cylinder to the next in the several above embodiments. This creates a continuous expansion motor with heat energy preserved through all the hot gaseous fluid flow and confined to mechanical energy extraction by the various, and now cascaded, power strokes. [0077] Ultimately, water vapor condensation concerns may limit the minimum desirable final exhaust temperature, but only after a far greater thermal-to-mechanical extraction has been accomplished relative to currently-in-use internal combustions engines. Distilled water may be sufficient for the disclosed purpose, but tap water, or, tap water with a de-calcification/de-crystallization agent alone may also be sufficient. Further, the fuel can carry de-calcification/de-crystallization capability. [0078] Many operating environments will be cold enough to freeze the water, causing a potential problem. However, this is likely manageable using, for example, flexible storage containers that can accommodate freeze expansion or similar technology. The final exhaust can also be used to melt the stored water over the longer operational term and a small high temperature thermal extraction channel from the 4 -stroke cylinders can be used to melt water initially for the near term start-up. One other possibility is an electric melt device which is most cost-effective for initial, temporary use. [0079] The combustion cylinder can be made up of, but not limited to, one or more of the following types of fuel and air cylinders including aspirated, fuel injected, carbureted, turbo-charged, super-charged, ram-charged, or any combination of these. The fuel can include, but is not limited to, the use of fuels including gasoline, diesel, propane, natural gas, alcohol, hydrogen, kerosene, or any other fuel known in the art. [0080] In another example, the combustion cylinders may include an Otto four-stroke cylinder, Atkinson four-stroke cylinder, Diesel four-stroke cylinder, or any other known four-stroke cylinder. [0081] While the expansion cylinders have generally been described as two-stroke cylinders, the invention would extend to four-stroke cylinder assemblies. [0082] Although a preferred embodiment of this invention has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this invention. For that reason, the following claims should be studied to determine the true scope and content of this invention.

Downstream expansion cylinders are associated with a combustion cylinder such that an overall surface area and displacement volume of the expansion cylinder is sufficient to lower the temperature of fluids associated with the combined engine to such an extent that a radiator can be eliminated in an associated vehicle, or other system. In a separate feature, a catalytic material is placed on surfaces which will “see” the hot exhaust gases such that catalytic conversion of impurities in the gases can be achieved within the engine itself. In yet another feature, water is recovered from a system having both a water injection expansion cylinder, and a combustion cylinder, and the recovered water is re-used for the expansion. In yet another feature, gearing is provided between the expansion cylinder and a combustion cylinder such that the output of the combined engine is optimized, and the two cylinders do not drive the crankshafts in a one-to-one fashion. In another feature the combustion cylinder's ignition timing is delayed (retarded) to manage thermal control of said combustion cylinder between it and a subsequent expansion cylinder or cylinders.

big_patent

CROSS REFERENCE TO RELATED APPLICATIONS This is a continuation of U.S. patent application Ser. No. 14/070,132, filed Nov. 1, 2013 and U.S. patent application Ser. No. 13/311,731 filed on Dec. 6, 2011 which are continuations of U.S. Pat. No. 8,614,008 issued on Dec. 24, 2013, which is a national stage application of PCT/FR2007/00536 filed on Mar. 29, 2007 which claims the benefit of PCT/FR2006/000898 filed on Apr. 19, 2006, the entire disclosures of which are hereby incorporated by reference herein. The invention concerns the fabrication of plates or blanks of coated steel intended to be welded and then heat treated to obtain parts having good mechanical characteristics and good corrosion resistance. BACKGROUND Some applications require steel parts combining high mechanical strength, high impact resistance and good corrosion resistance. This type of combination is particularly desirable in the automotive industry which requires a significant reduction in vehicle weight and excellent capacity to absorb energy in the event of a collision. This can be achieved in particular by using steel with very good mechanical characteristics having a martensitic or bainitic-martensitic microstructure: anti-intrusion, structural or safety components of automotive vehicles such as bumpers, door reinforcements, B-pillar reinforcements or roof reinforcements, for example, require the above qualities. Patent EP 0971044 discloses a fabrication method in which hot- or cold-rolled steel plate coated with aluminum of aluminum alloy is the starting material. After shaping to produce a part, and before heat treatment at a temperature above A c1 , the coating is heated to form a surface alloy by interdiffusion between the steel and the aluminum coating. This alloy prevents decarburization of the metal and oxidation during heat treatment in a furnace. It therefore eliminates the necessity for furnaces containing a special atmosphere. The presence of this alloy also obviates certain surface operations on the treated parts, such as shot blasting, which operations are necessary for plates having no coating. The parts are then cooled under conditions adapted to confer a tensile strength that can exceed 1500 MPa. With the aim of reducing vehicle weights, parts have been developed consisting of steel blanks of different compositions or different thicknesses continuously butt-welded together. These welded parts are known as “butt-welded blanks” Laser beam welding is a preferred method of assembling such blanks, exploiting the flexibility, quality and productivity characteristics of the process. After these welded blanks have been cold-pressed, parts are obtained having mechanical strength, pressability, impact absorption properties that vary within the parts themselves. It is therefore possible to provide the required properties at the appropriate location without imposing an unnecessary or costly penalty on all of the parts. The fabrication method described in patent EP 0971044 can be applied to butt-welded blanks in the following manner: starting from steel plate, possibly of different compositions or thicknesses, and having a metal pre-coating, butt-welded blanks are obtained by a welding process. These welded blanks then undergo heat treatment to form a surface alloy and are then hot-pressed and quenched. This produces quenched parts with thicknesses and intrinsic mechanical characteristics that vary and represent an ideal response to local loading requirements. SUMMARY OF THE INVENTION However, this fabrication method runs into considerable difficulties: when welding coated steel blanks, a portion of the initial surface pre-coating is transferred into the molten area created by the welding operation. These exogenous metal elements are concentrated in particular by strong convection currents in the liquid metal. These elements are segregated in particular in the interdendritic spaces in which the liquid fraction having the greatest concentration of dissolved elements is located. If austenizing follows with a view to quenching the welded blanks, these enriched areas become alloyed through interdiffusion with the iron or other elements of the matrix and form intermetallic areas. On subsequent mechanical loading, these intermetallic areas tend to be the site of onset of rupture under static or dynamic conditions. The overall deformability of the welded joints after heat treatment is therefore significantly reduced by the presence of these intermetallic areas resulting from welding and subsequent alloying and austenizing. It is therefore desirable to eliminate the source of these intermetallic areas, namely the initial surface metal coating liable to be melted during butt-welding. However, eliminating this source itself gives rise to a serious problem: the precoated area on either side of the future welded joint can be eliminated, for example by a mechanical process. The width of this area from which the pre-coating is removed must be at least equal to that of the future area melted by welding so as not to encourage subsequent formation of intermetallic areas. In practice, it must be much more than this, to allow for fluctuations in the width of the molten area during the assembly operation. Thus there exist after the welding operation areas on either side of the welded joint that no longer have any surface metal pre-coating. During further alloying and austenizing heat treatment, scale formation and decarburizing occur within these areas located next to the weld. These are areas that tend to corrode when the parts go into service because they are not protected by any coating. There is therefore a need for a fabrication process that prevents the formation of intermetallic areas within welded assemblies, which are sources of the onset of rupture. There is also a need for a fabrication process such that the welded and heat treated parts have good corrosion resistance. There is also a need for an economic fabrication process that can be integrated without difficulty into existing welding lines and that is compatible with subsequent pressing or heat treatment phases. There is also a need for a product on which operations of butt-welding, then of heat treatment, pressing and quenching, lead to the fabrication of a part having satisfactory ductility and good corrosion resistance. One particular requirement is for a total elongation across the welded joint greater than or equal to 4%. An object of the present invention is to solve the needs referred to above. The present invention therefore provides a plate consisting of a steel substrate and a precoat consisting of a layer of intermetallic alloy in contact with the substrate, topped by a layer of metal alloy. On at least one precoated face of the plate, an area situated at the periphery of the plate has the metal alloy layer removed. The precoat is preferably an alloy of aluminum or based on aluminum. The metal alloy layer of the precoat preferably comprises, by weight, from 8 to 11% of silicon, from 2 to 4% of iron, the remainder of the compound being aluminum and inevitable impurities. The width of the area from which the metal alloy layer has been removed is preferably between 0.2 and 2.2 mm. The width of the area from which the metal layer has been removed preferably varies. The thickness of the intermetallic alloy layer is preferably between 3 and 10 micrometers. The area from which the metal alloy has been removed is preferably produced by partly eliminating the metal alloy layer on at least one precoated face of the plate by brushing. The area from which the metal alloy has been removed can be produced by partially eliminating the alloy layer on at least one precoated face of the plate by means of a laser beam. The present invention also provides a welded blank obtained by butt-welding at least two plates according to a preferred embodiment of the present invention, the welded joint being produced on the edge contiguous with the area from which the metal alloy has been removed. The present invention further provides a part obtained by heat treatment and deformation of a welded blank according to a preferred embodiment of the present invention, the precoat being converted throughout its thickness by the heat treatment into an intermetallic alloy compound providing protection against corrosion and decarburization of the steel substrate. The present invention even further provides a plate, blank or part according to a preferred embodiment, the composition of the steel comprising, by weight: 0.10%≦C≦0.5%, 0.5%≦Mn≦3%, 0.1%≦Si≦1%, 0.01%≦Cr≦1%, Ti≦0.2%, Al≦0.1%, S≦0.05%, P≦0.1%, 0.0005%≦B≦0.010%, the remainder consisting of iron and inevitable impurities resulting from the production process. The composition of the steel preferably comprises, by weight: 0.15%≦C≦0.25%, 0.8%≦Mn≦1.8%, 0.1%≦Si≦0.35%, 0.01%≦Cr≦0.5%, Ti≦0.1%, Al≦0.1%, 5≦0.05%, P≦0.1%, 0.002%≦B≦0.005%, the remainder consisting of iron and inevitable impurities produced by the production process. The present invention additionally provides a part according to a preferred embodiment wherein the microstructure of the steel is martensitic, bainitic or bainitic-martensitic. The present invention also provides a method that includes the steps of coating a steel plate to obtain a precoat including an intermetallic alloy layer topped by a metal alloy layer and, then, on at least one face of the plate, removing the metal alloy layer in an area at the periphery of the plate. The width of the area may be preferably between 0.2 and 2.2 mm. The invention further provides a method of fabricating a precoated steel plate that includes of coating a steel plate to obtain a precoat having an intermetallic alloy layer topped by a metal alloy layer, on at least one face of the plate, removing the metal alloy layer in an area not totally contiguous with the periphery of the plate and cutting the plate in a plane so that the area from which the metal alloy has been removed is at the periphery of the cut plate. The width of the area from which the metal alloy has been removed and which is not totally contiguous with the periphery of the plate may be preferably between 0.4 and 30 mm. The precoating is preferably effected by dip coating with aluminum. The layer is preferably removed by brushing. In a preferred embodiment the layer is removed by the impact of a laser beam on the precoat. The invention also provides a method according to any one of the above embodiments in which the emissivity or reflectivity of the area over which the metal alloy layer is removed is measured, the measured value is compared with a reference value characteristic of the emissivity or reflectivity of the metal alloy layer, and the removal operation is stopped when the difference between the measured value and the reference value is above a critical value. The present invention also provides a method wherein the layer is removed by means of a laser beam, characterized in that the intensity or wavelength of the radiation emitted at the point of impact of the laser beam is measured, the measured value is compared with a reference value characteristic of the emissivity of the metal alloy layer, and the removal operation is stopped when the difference between the measured value and the reference value is above a critical value. The invention also provides a method wherein at least two plates fabricated according to any one of the above embodiments are butt-welded, the welded joint being produced on the edge contiguous with the area from which the metal alloy layer has been removed. The width before welding of the area from which the metal layer has been removed at the periphery of the plate is preferably 20 to 40% greater than half the width of the weld. The width of the area from which the metal alloy has been removed and which is not totally contiguous with the periphery of the plate is preferably 20 to 40% greater than the width of a weld. The present invention also provides a part fabrication method wherein a welded blank fabricated according to a preferred embodiment of the present invention is heated to form, by alloying between the steel substrate and the coating, an intermetallic alloy compound, and so as to confer a partially or totally austenitic structure on the steel, then the blank is hot deformed to obtain a part. The part is cooled at a rate adapted to confer the target mechanical characteristics. The rate of cooling is preferably above the critical rate for martensitic quenching. In a preferred embodiment the welding is effected by a laser beam. The welding is even more preferably effected by an electrical arc. The present invention also provides a use of a plate, blank or part according to any one of the above embodiments for the fabrication of structural or safety parts for motorized terrestrial automotive vehicles. BRIEF DESCRIPTION OF THE FIGURES Other features and advantages of the invention will become apparent in the course of the description given hereinafter by way of example and with reference to the following appended figures. FIG. 1 is a diagram showing one embodiment of plate according to the present invention before welding; FIG. 2 is a diagram of a second embodiment of plate according to the present invention; FIG. 3 is a diagram of an example of a butt-welded joint of the present invention; FIG. 4 is a macrograph of a welded joint of the present invention after austenizing and alloying heat treatment; FIG. 5 is a macrograph of a reference welded joint showing the appearance of harmful intermetallic areas within the molten metal; and FIG. 6 is a macrograph of plate according to the present invention before welding, from which plate the metal alloy has been removed locally using a laser beam. DETAILED DESCRIPTION As explained above, total elimination of the metal coating on either side of the joint before welding has led to localized corrosion problems. The inventors have surprisingly shown that eliminating a precise portion of the coating solves the problems referred to above. To explain the present invention, there are explained first certain characteristics of coated strip or plate usually produced by immersion in baths of molten zinc or aluminum or zinc or aluminum alloys. These continuous, so-called “dip” methods yield the following general morphology of the coatings: At the surface of the steel substrate of the plate an intermetallic alloy a few micrometers thick is precipitated, formed by a very fast reaction on immersion in the molten bath. These intermetallic alloys being relatively fragile, inhibitors are added to the molten bath in an attempt to limit the growth of this layer. In the case of zinc or aluminum alloy coatings, the alloys constituting this layer are often of the Fe x Al y type, in particular Fe 2 Al 5 . In the case of zinc alloy coatings, the presence of this aluminum-rich intermetallic layer is explained by the fact that the zinc baths often contain a small quantity of aluminum that plays an inhibitor role. This layer of intermetallic alloys can sometimes be of a complex nature, for example divided into two intermetallic sub-layers, the sub-layer in contact with the substrate being richer in iron. This layer of intermetallic alloys is topped by a metal alloy layer the composition of which is very close to that of the bath. A thicker or thinner metal layer is entrained by the plate as it leaves the molten bath, and this thickness can be controlled by means of jets of air or nitrogen. The inventors have shown that it is necessary to eliminate this layer locally to solve the problems referred to above, which is particularly advantageous. Consider more particularly FIG. 1 , showing a plate of the present invention. The term plate is to be understood in a broad sense and denotes in particular any strip or object obtained by cutting a strip, a coil or a sheet. In this particular example the plate has two faces and four edges. The present invention is not limited to this rectangular geometry, of course. FIG. 1 shows: A steel substrate 1 . This substrate can be of plate that is hot-rolled or cold-rolled, as a function of the required thickness, or of any other appropriate form. Superposed on the substrate, and in contact therewith, a pre-coating 2 is present on the two faces of the part. This pre-coating itself consists of: a layer of intermetallic alloy 3 in contact with the substrate 1 . As already explained, this layer is formed by reaction between the substrate and the molten metal of the bath. The precoat is advantageously an aluminum alloy or aluminum-based. This type of precoat is particularly suitable for subsequent heat treatment that forms an intermetallic compound by interdiffusion with the substrate 1 and (see below) localized removal of the surface layer. In particular, the metal alloy of the precoat can contain 8 to 11% by weight of silicon and 2 to 4% of iron, the remainder consisting of aluminum and inevitable impurities. Adding silicon enables reduction of the thickness of the intermetallic layer 3 . The periphery 5 of the plate is also shown. According to the invention, a portion 6 of the periphery does not carry the metal alloy layer 4 but retains the intermetallic alloy layer 3 . This portion 6 is intended to be placed in contact with another plate and then to be butt-welded in a plane defined by the edge 11 to form a blank. In a first embodiment, the layer 4 is advantageously removed by means of a brushing operation effected at the periphery 5 : the material removed by the brush is essentially the surface layer, which has the lowest hardness, i.e. the metal alloy layer 4 . The harder layer 3 will remain in place as the brush passes over it. Using an aluminum or aluminum-based precoat is particularly advantageous as the difference in hardness between the intermetallic alloy layer 3 and the metal layer 4 is very large. The person skilled in the art will know how to adapt the various parameters specific to the brushing operation, such as the choice of the kind of brush, the speed of rotation and of relative movement in translation, the pressure perpendicular to the surface, to carry out the removal as completely and quickly as possible, adapting them to the particular nature of the precoat. For example, a wire brush mounted on a rotary shaft driven in translation parallel to the edge of the part 6 could be used. In a second embodiment, the layer 4 is removed by a laser beam directed toward the periphery of the plate: interaction between this high energy density beam and the precoat causes vaporization and expulsion of the surface of the precoat. Given the different thermal and physical properties of the metal alloy layer 4 and the intermetallic layer 3 , the inventors have shown that a succession of short laser pulses with appropriate parameters leads to selective ablation of the metal layer 4 , leaving the layer 3 in place. The interaction of a pulsed laser beam directed toward the periphery of a coated plate and moved in translation relative to that plate therefore removes the peripheral metal layer 4 . The person skilled in the art will know how to adapt the various parameters, such as the choice of laser beam, the incident energy, the pulse duration, the speed of relative movement in translation between the beam and the plate, and the focusing of the beam onto the surface to carry out the ablation as quickly and completely as possible, adapting them to the particular nature of the precoat. For example, a Q-switch laser could be used, having a nominal power of a few hundred watts and delivering pulses with a duration of the order of 50 nanoseconds. The width of the removal area 6 can naturally be varied by means of successive contiguous ablations. The width of the area 6 from which the metal layer has been removed must be adjusted to enable: welding with no introduction of any element of the precoat into the molten area, sufficient corrosion resistance of the welded assembly after subsequent alloying and austenizing heat treatment. The inventors have shown that the above conditions are satisfied if the width of the area 6 is 20% to 40% greater than half the width of the molten area created when butt-welding blanks. The minimum value of 20% ensures that the precoat is not introduced into the molten metal during welding, and the value of 40% ensures satisfactory corrosion resistance. Given the welding conditions for plate from 1 to 3 mm thick, the width of the area 6 is between 0.2 and 2.2 mm. This situation is represented in FIG. 3 , which shows diagrammatically in section after welding plate comprising a precoat 2 formed of an intermetallic alloy layer 3 and a metal layer 4 . The molten area 10 has its axial plane 9 in the welding direction. The dashed lines show the initial extent of an area 6 melted by the welding operation. FIG. 3 illustrates the situation in which the weld is globally symmetrically on the two opposite faces of the plate. Under these conditions, the width of the area 6 is exactly the same on both faces. However, as a function of the welding process used and the parameters of that process, the weld can have an asymmetrical appearance. According to the invention, the width of the area 6 can then be coordinated to this asymmetry so that this width is slightly greater than half the width of the molten area 10 on each of the respective two faces. Under these conditions, the width of the area 6 differs from that of the area 6 ′ shown in FIG. 3 . If welding conditions evolve during an assembly operation, for example to take account of local modification of geometry or thickness, the width of the area 6 can also be coordinated with the corresponding variation of the width of the molten area along the welded periphery of the plate. The width of the area 6 naturally increases if local conditions lead to the formation of a wider weld. In the case of welding two coated plates of different thickness, the width of the area 6 can also be different on the welded peripheral portion of each of the two plates. In a variant of the invention shown in FIG. 2 , the layer 4 is removed over an area 7 of a coated plate that is not totally contiguous with the periphery 5 of the plate. The plate is then cut in an axial plane 8 perpendicular thereto, for example by a slitting process. A plate as shown in FIG. 1 is then obtained. The width removed is 20% to 40% greater than the width of the molten area that would be produced by a welding operation in the axial plane 8 . In one variant of the invention, the width removed is between 0.4 and 30 mm. The minimum value corresponds to a width such that cutting in the axial plane 8 produces two plates having a very narrow removal area 0.2 mm wide on each of the two plates. The maximum value of 30 mm corresponds to a removal width well suited to industrial tools for performing such removal. A subsequent cutting operation can be effected, not on the axial plane 8 situated in the middle of the removal area, but at a location adapted to produce a plate whose removal width is slightly greater than half the width of the molten area produced by a welding operation, defined by the conditions of the invention. As explained above, the removed widths ensure that the metal coating is not introduced into the molten metal during subsequent welding of the plate and also that the welded blank is corrosion resistant after heat treatment. Removal of the metal layer 4 can be monitored by means of micrographic examination. However, it has also been shown that the efficiency of the removal operation can be checked very quickly by optical inspection: there is a difference in appearance between the metal layer 4 and the underlying intermetallic layer 3 , which is darker. The removal operation must therefore continue and be stopped when there is seen in the area 6 a significant change of tone relative to the surface coating. It is therefore possible to monitor removal by spectrometer reflectivity or emissivity measurement: the area 6 is illuminated by a light source, one or more optical sensors being directed towards this area. The measured value corresponds to the reflected energy. That value is compared with a reference value corresponding to the emissivity or reflectivity of the metal layer 4 or with a value measured by another sensor directed toward the metal layer. It is also possible to measure the variation of the reflected energy as a function of time. If the layer 6 is flush with the surface, the energy collected is lower than that corresponding to the metal alloy layer 4 . The precise moment at which the removal operation reaches the layer 3 can therefore be determined by previous calibration. In the case of coating removal by laser ablation, it is also possible to analyze the intensity or the wavelength of the radiation emitted at the point of impact of the laser beam on the precoated plate. The intensity and the wavelength are modified when the layer 4 has been eliminated and the laser beam impacts on the layer 3 . The thickness of the layer removed can therefore be monitored in the following manner: the intensity or the wavelength of the radiation emitted at the point of impact of the laser beam is measured, that measured value is compared with a reference value characteristic of the emissivity of the metal alloy layer 4 , and the removal operation is stopped when the difference between the measured value and the reference value is above a predetermined critical value. Depending on specific constraints, this step of removing the metal alloy layer can be carried out at various stages of the production process, and in particular: either after unwinding coils fabricated on continuous rolling mill trains, before cutting to form a smaller format plate, or before welding the cut plate. In the method of the invention, a hot- or cold-rolled steel plate with the following composition by weight is the starting material: carbon content between 0.10 and 0.5%, and preferably between 0.15 and 0.25% by weight. This element impacts greatly on the quenchability and on the mechanical strength obtained after cooling that follows the alloying and austenizing of the welded blanks. Below a content of 0.10% by weight, the quenchability is too low and the strength properties are insufficient. In contrast, beyond a content of 0.5% by weight, the risk of defects appearing during quenching is increased, especially for the thickest parts. A carbon content between 0.15 and 0.25% produces a tensile strength between about 1250 and 1650 MPa. Apart from its role as a deoxidant, manganese also has a significant effect on quenchability, in particular if its concentration by weight is at least 0.5% and preferably 0.8%. However, too great a quantity (3% by weight, or preferably 1.8%) leads to risks of excessive segregation. The silicon content of the steel must be between 0.1 and 1% by weight, and preferably between 0.1 and 0.35%. Apart from its role of deoxidizing the liquid steel, this element contributes to hardening. Its content must nevertheless be limited to avoid excessive formation of oxides and to encourage coatability. Beyond a content above 0.01%, chromium increases quenchability and contributes to obtaining high strength after the hot forming operation, in the various portions of the part after cooling following the austenizing and alloying heat treatment. Above a content equal to 1% (preferably 0.5%), the contribution of chromium to obtaining homogeneous mechanical properties reaches saturation. Aluminum favors deoxidation and precipitation of nitrogen. In amounts above 0.1% by weight, coarse aluminates form during production, which is an incentive to limit the content to this value. Excessive quantities of sulfur and phosphorus lead to increased weakness. For this reason it is preferable to limit their respective contents to 0.05 and 0.1% by weight. Boron, the content of which must be between 0.0005 and 0.010% by weight, and preferably between 0.002 and 0.005% by weight, has a large impact on quenchability. Below a content of 0.0005%, insufficient effect is achieved vis à vis quenchability. The full effect is obtained for a content of 0.002%. The maximum boron content must be less than 0.010%, and preferably 0.005%, in order not to degrade toughness. Titanium has a high affinity for nitrogen and therefore contributes to protecting the boron so that this element is found in free form to have its full effect on quenchability. Above 0.2%, and more particularly 0.1%, there is however a risk of forming coarse titanium nitrides in the liquid steel, which have a harmful effect on toughness. After preparation of the plate according to any of the methods described above, they are assembled by welding to obtain a welded blank. More than two plates can naturally be assembled to fabricate complex finished parts. The plates can be of different thickness or composition to provide the required properties locally. Welding is effected after placing the plates edge-to-edge, the areas with no metal alloy layer being in contact with each other. Welding is therefore effected along the edge contiguous with the areas 6 where the metal alloy layer has been removed. In the context of the invention, any continuous welding means can be used appropriate to the thicknesses and to the productivity and quality conditions required for the welded joints, and in particular: laser beam welding, electric arc welding, and in particular the GTAW (Gas Tungsten Arc Welding), plasma, MIG (Metal Inert Gas) or MAG (Metal Active Gas) processes. Under the conditions of the invention, the welding operation does not lead to remelting of a portion of the metal coating 4 , elements whereof would thereafter be found in the molten area. Only a minimal quantity of the intermetallic alloy layer 3 is remelted by this operation into the molten area. As the following example shows, this very limited quantity has no influence on the metallurgical quality or the mechanical properties of the welded joint after alloying and austenizing heat treatment. The welded blank is then heated to bring about conjointly: A surface alloying treatment in which elements of the steel substrate, in particular iron, manganese and silicon, diffuse into the precoat. This forms a surface intermetallic alloy compound the melting point of which is significantly higher than that of the metal alloy layer 4 . The presence of this compound during heat treatment prevents oxidation and decarburization of the underlying steel. Austenizing of the base steel, either partial or total. The heating is advantageously effected in a furnace so that the part reaches a temperature between Ac1 and Ac3+100° C. Ac1 and Ac3 are respectively the start and end temperatures of the austenitic transformation that occurs on heating. According to the invention, this temperature is maintained for a time greater than or equal to 20 s so as to render uniform the temperature and microstructure at the various points of the part. Under the conditions of the present invention, during this heating phase, no brittle intermetallic areas are formed within the molten metal, which would be harmful to the mechanical properties of the part. This is followed by hot deformation of the blank to its final shape as a part, this step being favored by the reduction of the creep limit and the increase of the ductility of the steel with temperature. Starting from a structure that is partly or totally austenitic at high temperature, the part is then cooled under appropriate conditions to confer the target mechanical characteristics: in particular, the part can be held in a tooling during cooling, and the tooling can itself be cooled to encourage the evacuation of heat. To obtain good mechanical properties, it is preferable to produce martensitic, bainitic or bainitic-martensitic microstructures. In the area 6 on either side of the welded joint, the intermetallic layer 3 , which is between 3 and 10 micrometers thick before heat treatment, is alloyed with the steel substrate and produces good corrosion resistance. EXAMPLE The following embodiments show by way of example other advantages conferred by the present invention. They concern a cold-rolled steel strip 1.5 mm thick, with the following composition by weight: TABLE 1 Composition of the steel (% by weight) C Mn Si S P Al Cr Ti B 0.224 1.160 0.226 0.005 0.013 0.044 0.189 0.041 0.0031 The steel strip was precoated by dipping it in a molten bath of an aluminum alloy containing 9.3% of silicon and 2.8% of iron, the remainder consisting of aluminum and inevitable impurities. The strip was then cut into plates with a format of 300×500 mm 2 . These have on each face a precoat comprising a layer of intermetallic alloy comprising mostly Fe 2 Al 3 , Fe 2 Al 5 and Fe x Al y Si z . This 5 micrometers thick layer in contact with the steel substrate has a 20 micrometers thick layer of Al—Si metal alloy on top of it. Before laser beam welding, four different preparation methods were used: Method I (according to the present invention): the Al—Si metal alloy layer was removed by longitudinal brushing over a width of 1.1 mm from the edge of the plate, on the 500 mm long side. Brushing was effected in exactly the same way on both faces using an 80 mm diameter “Spiraband” wire brush mounted on an angled rotary system, guided in movement in translation on a counterweight bench. The brushing force is approximately 35 N at the point of brush/blank contact, and the speed of movement of the brush 10 m/min. This brushing eliminates the metal alloy layer, leaving only the 5 micrometer intermetallic alloy layer in the brushed area. Method II (according to the present invention): the Al—Si metal alloy layer was removed by laser ablation over a width of 0.9 mm from the edge of the plate. The laser ablation was carried out in exactly the same way on both faces using a Q-switch laser with a nominal energy of 450 W delivering 70 ns pulses. The pulse energy is 42 mJ. The constant speed of movement in translation of the laser beam relative to the plate is 20 m/min. FIG. 6 shows that this laser ablation eliminates the metal alloy layer 4 leaving only the 5 micrometer intermetallic alloy layer 3 in the treated area. Method R1 (not according to the invention): all of the precoat, comprising the metal alloy layer and the intermetallic alloy, was mechanically removed over a width of 1.1 mm, and therefore identical to that of method 1, by means of a carbide plate type tool for fast machining, in longitudinal translation. As a result, subsequent welding is carried out in an area with all of the precoat removed on either side of the joint. Method R2 (not according to the invention): laser welding was effected on precoated plate with no particular preparation of the periphery. The above plates were laser beam welded under the following conditions: nominal power: 6 kW, welding speed: 4 m/minute. Given the width of the weld, in method I, there is found the presence of an area with no metal alloy over a width of approximately 0.3 mm following production of the welded joints. The welded blanks were subjected to alloying and austenizing heat treatment including heating to a temperature of 920° C., which was maintained for 7 minutes. These conditions lead to complete austenitic transformation of the steel of the substrate. During this heating and constant temperature phase, it is found that the aluminum-silicon-based precoat forms an intermetallic compound throughout its thickness by alloying with the base steel. This alloy coating has a high melting point and a high hardness, features high corrosion resistance, and prevents oxidation and decarburization of the underlying base steel during and after the heating phase. After the phase of heating to 920° C., the parts were hot-deformed and cooled. Subsequent cooling between jigs yielded a martensitic structure. The tensile R m of the steel substrate obtained after such treatment is above 1450 MPa. The following techniques were then used to characterize the welded joints in the parts obtained in this way: Micrographic sections show the presence of any intermetallic areas within the welded joints. Mechanical tension tests across welded joints in samples 12.5×50 mm 2 determines the tensile strength R m and the total elongation. Accelerated corrosion tests were carried out according to the DIN 50021, 50017, and 50014 standards. These tests include, following salt mist spraying, cycles alternating dry phases at 23° C. and wet phases at 40° C. Table 2 sets out the results of these characterizations: TABLE 2 Welded joint characteristics after heat treatment Fragile intermetallic areas within Rm Corrosion Method welded joints (MPa) A(%) resistance I (according to the None >1450 ≧4 ∘ present invention) II (according to the None >1450 ≧4 ∘ present invention) R1 (not according to None >1450 ≧4 ● the invention) R2 (not according to Present 1230 ≦1 ∘ the invention) ∘: Satisfactory ●: not satisfactory Under the quenching conditions required after heat treatment, the microstructure of the base metal and the molten area during welding is totally martensitic with the above four methods. In the case of method I of the invention, the melted area contains no intermetallic area, as FIG. 4 shows. On the other hand, in the method R2, note the presence of intermetallic areas (see FIG. 5 ), in particular towards the periphery of the melted area where the elements of the precoat were concentrated by spontaneous convection currents in the liquid bath caused by a Marangoni effect. These large intermetallic areas, which can be oriented substantially perpendicularly to the mechanical load, act as stress concentration and onset of rupture effects. Elongation in the crosswise direction is in particular reduced by the presence of these intermetallic areas: in the absence of these areas, the elongation is above 4%. It drops to below 1% when they are present. No significant difference in mechanical characteristics (strength and elongation) is noted between the method I of the invention and the method R1. This indicates that the thin layer of intermetallic alloy left in place by brushing and remelted by welding does not lead to the formation of brittle areas within the molten metal, as FIG. 4 shows. In the case of the method R1, corrosion resistance is reduced: the steel is totally bared on either side of the welded joint by the total removal of the precoat. Lacking corrosion protection, red rust is then seen to appear in the heat-affected areas on either side of the weld. Thus the method of the invention simultaneously achieves good ductility of the welded joint after treatment and good corrosion resistance. Depending on the composition of the steel, in particular its carbon content and its manganese, chromium and boron content, the maximum strength of the parts can be adapted to the target use. Such parts will be used with profit for the fabrication of safety parts, and in particular anti-intrusion or underbody parts, reinforcing bars, B-pillars, for the construction of automotive vehicles.

A method of forming a steel part is provided. The method includes the steps of coating a first steel plate to obtain a first precoat upon the first steel plate so as to define a first base, a first intermetallic alloy layer on the first base and a first metal alloy layer on the first intermetallic alloy layer. On a first face of the first steel plate the first metal alloy layer is removed in a first area of the first steel plate, while at least part of the first intermetallic alloy layer in the first area remains. A second steel plate is coated to obtain a second precoat upon the second steel plate so as to define a second base, a second intermetallic alloy layer on the second base and a second metal alloy layer on the second intermetallic alloy layer. On a second face of the second steel plate, the second metal alloy layer is removed in a second area of the second metal plate, while at least part of the second intermetallic alloy layer in the second area remains. After removal of the first and second metal alloy layers, the first steel plate is butt-welded to the second steel plate at the first and second areas to form a welded blank. A heat treatment is performed on the welded blank. The welded blank is shaped after the heat treatment into the steel part. A steel part is also provided.

big_patent

The present application is a continuation of U.S. patent application Ser. No. 11/942,576, filed Nov. 19, 2007, entitled, “Supervisory Control and Data Acquisition System for Energy Extracting Vessel Navigation,” the contents of which is hereby incorporated by reference in its entirety. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is generally in the field of supervisory control and data acquisition systems. More specifically, the present invention is embodied in a remote control system particularly for operation and navigation of a mobile structure that optimally recovers energy from an offshore marine environment. 2. Description of the Related Art While many systems exist today for recovery of wind energy and water current or wave energy, most systems are stationary, mounted on or anchored to the sea floor. Many other hydrokinetic turbine energy systems exist today that affix to sailing vessels overcoming the limitations of fixed stationary structures. Nonetheless, all wind and hydrokinetic systems have the fundamental limitation of total possible recoverable energy at any given time being directly proportional to the cube of the velocity of the motive fluids. This inherent limitation renders most of these systems economically infeasible when considering the manufacturing and operational costs of the system and the typical ambient wind and water current vectors rarely summing to a magnitude greater than twenty knots. While sailing vessel designs exist such as catamarans, which reputedly can exceed true wind speed, the function of immersing a hydrokinetic turbine as an appendage of such a vessel immediately incurs drag upon the vessel ultimately to reduce the speed of the motive fluid through the turbine to unprofitable energy recovery rates. U.S. Pat. No. 7,298,056 for a Turbine-Integrated Hydrofoil addresses an implementation of a drag-reducing appendage as means to an economically viable solution. The specification of this reference application suggests remote controlled operation but does not expressly depict intentional unmanned operation of such a mobile structure for economic benefit into an environment of such high energy as to otherwise present conditions hazardous to human crews. The aforementioned reference patent application also does not delineate the various parts of the communication system in detail, thus does not enable in full, clear, concise, and exact terms, one skilled in the art to reduce such a remote control system to practice. Therefore, there exists a need for a novel Supervisory Control And Data Acquisition system that remotely controls the operation and particularly the navigation of a mobile structure that can cost-effectively extract energy in an optimal manner from an environment that inherently presents untenable risk to human life. SUMMARY OF THE INVENTION The present invention is directed to a novel Supervisory Control And Data Acquisition (SCADA) remote control system for a mobile structure that recovers naturally occurring energy from severe weather patterns. The present specification embodies an offshore energy recovery system wherein an algorithm optimizes efficiency in the system by accounting for data from weather observations, and from sensors on the mobile structure, while relating these data points to performance models for the mobile structure itself The present specification exemplifies the use of the algorithm in navigating a sailing vessel optimized to reduce drag while responding to wind and water velocity vectors by adjusting points of sail, rudder rotation, openness of turbine gates, and ballast draft, through control outputs from the microprocessor system on-board the sailing vessel. The SCADA system includes computer servers that gather data through diverse means such as Global Position Satellite (GPS) systems, weather satellite systems of the National Aeronautics and Space Administration (NASA), the National Oceanic and Atmospheric Administration (NOAA), and United States Air Force Defense Meteorological Satellite Program (DMSP) communicated through various geographic and weather data resources including but not limited to the Geographic Information System (GIS) of NOAA's National Weather Service (NWS) along with all other weather information sources available from its National Hurricane Center (NHC) and Tropical Prediction Center (TPC). The SCADA computer servers run Human Machine Interface (HMI) secure software applications which communicate to microprocessor systems running client software with a Graphical User Interface (GUI) to allow remote humans to optionally interact and choose mission critical navigation plans. In addition, the present invention is not limited to implementation of the exemplary referenced Turbine-Integrated Hydrofoil system of U.S. Pat. No. 7,298,056. The present invention applies to remote control of any system that exploits energy from weather patterns that avail formidable amounts of naturally occurring energy. Any mobile structure that extracts energy from electrical storms, windstorms, offshore tropical storms or hurricanes, or any aerodynamic or hydrokinetic electromechanical mobile system for renewable energy recovery under remote control especially benefits from the present invention. Otherwise whereby without the present invention that enables a mobile system to automatically track environmental conditions hazardous to humans anywhere in the universe, such risks of danger renders manned operation undesirable and thus the cost benefits and ease of implementation of such energy exploitation systems unrealizable. Finally, because the system embodied within the present invention comprises an algorithm that optimizes energy extraction using yield functions derived from weather and geospatial data and vessel performance models, the same system using just the path cost algorithm without weighing energy extraction yield factors into the cost of travel, may guide navigation of vessels for logistics-only purposes past such weather patterns. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a top-level view of all components in an exemplary system in accordance with one embodiment of the present invention. FIG. 2 illustrates a block diagram of the control, communications, and computer systems running server and client software applications in an exemplary system. FIG. 3 illustrates electromechanical circuits for actuating control of various mechanisms affecting position and velocity of the mobile structure in an exemplary system. FIG. 4 illustrates a representation of the graphical user interface on a client computer system in one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The present invention pertains to a remote control system and algorithm for supervisory control and data acquisition enabling navigation and automatic operation of a mobile energy recovery system. The following description contains specific information pertaining to various embodiments and implementations of the invention. One skilled in the art will recognize that one may practice the present invention in a manner different from that specifically depicted in the present specification. Furthermore, the present specification need not represent some of the specific details of the present invention in order to not obscure the invention. A person of ordinary skill in the art would have knowledge of such specific details not described in the present specification. Obviously, others may omit or only partially implement some features of the present invention and remain well within the scope and spirit of the present invention. The following drawings and their accompanying detailed description apply as merely exemplary and not restrictive embodiments of the invention. To maintain brevity, the present specification has not exhaustively described all other embodiments of the invention that use the principles of the present invention and has not exhaustively illustrated all other embodiments in the present drawings. FIG. 1 illustrates a top-level diagram of all components of an exemplary practical embodiment of the present invention. Block 100 represents an offshore mobile energy recovery structure in the process of energy extraction in an exemplary embodiment of the present invention. Exemplary embodiments of mobile structure 100 include sailing or propelled vessels or barges or any mobile buoyant energy recovery system known by one of ordinary skill in the art. A non-exhaustive list of mobile structures 100 for energy recovery includes: the Turbine-Integrated Hydrofoil of U.S. Pat. No. 7,298,056; any wave energy conversion system with propulsion means allowing relocation; one or plural wind turbines on floating platforms with propulsion means allowing relocation; or one or plural lightening rods on floating platforms with propulsion means allowing relocation for extracting energy from electrical storms; or any mobile system that extracts energy from pneumatic and/or hydrokinetic sources with aerodynamic and/or hydrodynamic drive means. The aforementioned list of mobile structures 100 represents purely exemplary embodiments by no means restrictive of mobile structure 100 embodiments within the scope and spirit of the present invention. FIG. 1 further depicts mobile structure 100 in the process of energy extraction circumnavigating what appears to be a vortical weather pattern 101 . As one may infer from the counterclockwise vortex streamlines, the weather pattern 101 manifests in the northern hemisphere as implied by the Coriolis effect. Note that this representation of a weather pattern 101 is strictly exemplary and that a weather pattern 101 consistent with a description of a cyclone in the southern hemisphere; a typhoon in south east Asia; a williwaw non-vortical gap flow or barrier jet wind storm offshore from the Alaskan coast or similar weather pattern elsewhere; any tropical storm; or any hurricane, remains well within the scope of a weather pattern 101 for the purposes of the present invention. The exemplary embodiment further comprises a central service facility 102 for the purpose of service logging, maintenance, and bulk energy storage for later distribution, and especially where the remote control of the mobile structure 100 occurs. One may note that energy storage comprises compressed hydrogen, metal hydride storage, or charged batteries or capacitors, as long as the mobile structure 104 and the central service facility 102 employ energy storage systems with compatible upload interfaces. The graphical representation of the central service facility 102 in FIG. 1 evokes the notion of a large vessel such as a tanker ship, but a port facility equally qualifies as a central service facility 102 within the scope of the present invention. The depiction of mobile structure 103 en route to the weather pattern 101 and mobile structure 104 returning to the central service facility 102 emphasizes that complete round-trip operation of one or plural mobile structures 100 , 103 , 104 , whether engaged in energy recovery as in mobile structure 100 or returning a payload as in mobile structure 104 , essentially comprises tasks performed by the remote control system of the present invention. Essential to the operation of the complete SCADA system is the communication of data from various sources. FIG. 1 further illustrates three types of satellites, Global Position Satellites (GPS) 106 , weather satellites 105 , and telecommunications satellites 107 , comprising the SCADA remote control system in this exemplary embodiment. In practically all embodiments, the SCADA system tracks the position and velocity of the mobile structure 100 through a GPS 106 system. The central service facility 102 , if itself indeed mobile, likely also tracks its own location using a GPS 106 system. This specification will further expound upon the use of the GPS 106 system as a SCADA control algorithm input in subsequent paragraphs describing FIG. 4 . This specification will hereinafter use the generic term weather satellite 105 when referring to any of the weather tracking satellites availing weather data to various government and private entities. A non-exhaustive list of weather satellites 105 able to serve this function includes: the NASA QuikSCAT; the NOAA Synthetic Aperture Radar (SAR) satellites including Radarsat-1, and Envisat satellites; any of the satellites serving the NOAA Satellite Services Division (SSD) National Environmental Satellite Data and Information Service (NESDIS) including Meteosat-7, Eumetsat, MTSAT-1R, Global Earth Observation Systems, GOES-EAST (GOES-12), GOES-WEST (GOES-11), GOES-9, GOES-10, GOES-13, or POES satellites. The aforementioned list of weather satellites 105 represents purely exemplary embodiments by no means restrictive of weather satellites 105 embodiments within the scope and spirit of the present invention. Telecommunications satellites 107 represent how data communicates between the central service facility 102 and one or plural of many possible entities including those accessible through the Internet from where all weather data in this exemplary embodiment disseminates, such as from the National Weather Service 108 Geographic Information System (GIS) computer servers. Besides weather satellite 105 data, the NWS 108 GIS and many other such entities including those accessible through the Internet disseminate weather data from other sources such as: oceanic weather buoys; coastal meteorology stations, Coastal Marine Automated Network Stations (C-MAN); NOAA Aircraft Operations Center; NOAA National Hurricane Center (NHC) Aircraft Reconnaissance “Hurricane Hunters”; United States Air Force 53rd Weather Reconnaissance Squadron; USAF GPS Dropwindsondes; and RIDGE radar. The aforementioned non-exhaustive list of alternate sources of weather information disseminated from the NWS 108 or similar weather data disseminating entities including those accessible through the Internet represents exemplary but not restrictive sources of weather data alternate to weather satellite 105 sources. The physical location of dissemination of data such as within an NWS 108 GIS computer server or similar weather data disseminating entities including those accessible through the Internet appears terrestrial-based; in other words, the hardware resides on land 109 . Obviously, if the central service facility 102 existed at a port on shore, a more cost-effective and potentially higher bandwidth data communications link such as fiber optic cable thus supplants the telecommunications satellites 107 in communication with the NWS 108 GIS or other similar weather data disseminating computer servers. Telecommunications satellites 107 perform another function in an exemplary system such as communicating between the central service facility 102 and the mobile structure 100 . However, the preferred embodiment employs a more cost-effective wireless communications system communicating between the mobile structure 100 and the central service facility 102 upon which this present specification will subsequently expound. FIG. 2 illustrates an exemplary system wherein the mobile structure 100 further comprises a control and communications microprocessor system 200 along with the central service facility 102 further comprising a microprocessor system running secure server 204 software applications and workstations 209 running secure client software applications communicating with the server 204 via a Local Area, Network (LAN) 207 . In some embodiments, all the secure server and client software applications running within the central service facility 102 may execute on a single large computing system, but given today's state of the art computing technology, a multi-processor server-client LAN 207 topology offers the greatest advantage in terms of flexible architecture, cost-effective computing power, reliability, scalability, and durability. In some embodiments, the control and communications microprocessor system 200 located within the mobile structure 100 comprises a type of microprocessor computing system 200 known as a Programmable Logic Controller (PLC). Traditionally evolving from industrial process control applications, a PLC 200 comprises ruggedized hardware robust to physical environments demanding resistance to mechanical shock and vibration, temperature extremes, and specifically, customization for control and communication purposes fitting SCADA system applications. Regardless of whether the microprocessor system 200 comprises custom hardware or an off-the-shelf product from a renowned PLC vendor, the microprocessor system 200 needs to execute certain functions as depicted in FIG. 2 in practically all embodiments. The microprocessor system 200 will require input, output, and input/output (I/O) functions 201 for communicating with sensors and control circuits. A wide variety of sensor and control circuits communicating with the microprocessor system 200 through I/O 201 necessary for inputting and outputting variables to the preferred SCADA control algorithm exist within most practical embodiments of the mobile structure 100 . A non-exhaustive list of sensor and control circuits 201 includes: accelerometers and gyroscopes for analysis of vessel 100 stability also known as attitude, or heeling and listing, along with heading, or to borrow aviation terms, pitch, roll and yaw, respectively, and rendering virtual contours of immediate local oceanic surface and possibly advanced features such as dead reckoning; ballast draft readings and adjustments; a wind vane and anemometer or if combined into a single unit an aerovane for analysis of apparent wind vectors' direction and magnitude respectively; fuel gauges for both propulsion motor fuel reserves and output fuel from energy recovery functions and thus mobile structure 100 weight and energy efficiency; electrolyzer electrode temperature gauges; energy extracting electric generator armature voltage readings and field current adjustments; energy extracting turbine gate opening readings and adjustments affecting mobile structure 100 drag; a compass for mobile structure 100 direction; a GPS receiver 202 for tracking position, velocity, and using way points to compare wind sensor data comprising local apparent wind vectors, minus mobile structure 100 velocity to determine local true wind vector, then comparing that empirical data to data from weather satellites 105 and other sources measuring and/or estimating true wind velocity; rudder rotation readings and adjustments; propeller rotational speed readings and adjustments; sail trim and/or boom rotation readings and adjustments; radar and/or sonar systems for physical object detection, identification, and avoidance; and one or plural video camera data streams allowing actual views of the surrounding environment of the mobile structure 100 , and physical object visual pattern matching. The aforementioned list of microprocessor I/O functions 201 represents purely exemplary embodiments by no means restrictive of I/O function 201 embodiments within the scope and spirit of the present invention. In terms of SCADA software data structure development, any or all of the aforementioned I/O functions 201 constitute one or plural SCADA object tag definitions, for various software layers to communicate from the mobile structure 100 microprocessor system 200 ; to the central service facility 102 servers 204 ; to the central service facility 102 workstations 209 . Weather satellite 105 data or alternate sources of weather information disseminated from the NWS 108 or similar weather data disseminating entities including those accessible through the Internet will also constitute SCADA object tag definitions. This specification will further expound upon the use of the SCADA object tags within the preferred SCADA control algorithm in subsequent paragraphs describing FIG. 4 . The remaining functions associated with the microprocessor system 200 in FIG. 2 include the antenna 202 representing the receiver for the GPS system. The other antenna 203 represents the means by which the microprocessor system 200 of the mobile structure 100 receives and transmits over a wireless physical medium to the central service facility 102 server 204 . As previously mentioned, one system of communication 203 embodies satellite 107 telecommunications. In the preferred embodiments, as long as the mobile structure 100 remains within line-of-sight with the central service facility 102 , as one presumes on the open sea, a point-to-point Code Division Multiple Access (CDMA) system permitting high bandwidth data including video camera data streams provides the communications function in the preferred embodiment. Another wireless physical medium in the form of point-to-point Ultra High Frequency (UHF) radio exists. While of lower bandwidth, UHF offers wider range and does not require line-of-sight as does CDMA, and thus an embodiment of the present invention may incorporate UHF as a redundant back-up in case of loss-of-signal for the CDMA. For SCADA systems without video data streams, UHF may actually serve the primary communication channel function. These wireless telecommunications systems represent exemplary embodiments without restriction to other possible wireless telecommunications systems embodied within the scope and spirit of the present invention. The central service facility 102 houses the server 204 for the primary purpose of aggregating weather data from any one or plural weather data disseminating entities including those accessible through the internet such as the NWS 108 . Some embodiments achieve robust data reliability through implementing redundant or multiple servers 204 . The telecommunications system represented in FIG. 2 includes the link 205 to the mobile structure 100 and the link 206 to the NWS 108 or similar weather data disseminating entities including the Internet itself. On the central service facility 102 , link 205 and link 206 complete the channel with the mobile structure 100 and weather data disseminating entities including those accessible through the internet such as the NWS 108 , respectively, using physical mediums and protocols as previously discussed. The LAN 207 in exemplary embodiments conforms to such network standards as IEEE 802.3, 802.3u, 802.11a,b, or g or any standard suiting the needs of the server-client software applications in the present invention, and the Network Interface Cards (NIC's) 208 , hardware generally integrated into the workstations 209 , likewise conform to the aforementioned exemplary network standards. All embodiments very likely operate under the most common protocol implemented today, Transmission Control Protocol/Internet Protocol (TCP/IP) for passing of packets of data associated with SCADA object tags between the server 204 , the workstations 209 , and the PLC 200 . In an embodiment wherein the central service facility 102 resides on land 109 , the LAN 207 accesses a Wide Area Network (WAN) 211 for weather satellite 105 data or alternate sources of weather information disseminated from the NWS 108 or similar weather data disseminating entities including those accessible through the Internet through a router 210 instead of through a telecommunications satellite 107 as in an offshore central service facility 102 . Either the server 204 or the router 210 may execute firewall security software during network communications. Other forms of secure communication between the server 204 , the workstations 209 , and the PLC 200 may include Internet Protocol Security (IPSec) with packet encryption and decryption occurring during transmission and reception within TCP/IP for all the aforementioned computer systems. These network standards and protocols examples represent several of many possible network standards and protocols configurations within the scope of the present invention and one must view these network standards and protocols configurations as exemplary, not restrictive. FIG. 3 illustrates the control-actuating electromechanical circuits in an embodiment of the mobile structure 100 . Exemplary controls on the mobile structure 100 , 103 , 104 include rudder rotation, propeller rotation in propelled embodiments, and sail trim or boom rotation in sailing embodiments. Actuation of all mechanical members begins with motor 300 activation by driving a current 317 through the motor's 300 winding 316 . As shown in FIG. 3 , the rotor 302 of the motor 300 affixed to a small gear 303 couples to a larger gear 306 affixed to an intermediate gear shaft 307 affixed to another small gear 308 coupled to another larger gear 309 affixed to the final drive shaft 310 in a direct drive system or to a worm 310 A in a worm drive system. A system comprising such gear ratios as depicted in FIG. 3 serves the purpose of reducing torque on the motor 300 that generally exhibits a high rotational velocity, low torque characteristic in lightweight, economical motor 300 embodiments. For actuating a propeller, the preferred embodiment obviously installs a motor 300 capable of greater torque and variable speed. In the worm drive embodiment, the worm 310 A and worm gear 311 interface further reduces the torque on the rotor 302 compared to that on the final drive shaft 312 . An embodiment comprising a worm drive also affords the advantage of the braking effect such that the direction of transmission always goes from the rotor 302 to the shaft 312 and not vice versa given an appropriate coefficient of friction between the worm 310 A and the worm gear 311 . Other embodiments rely upon the detent torque of a stepper motor 300 for braking. In other embodiments, such as servo motors 300 or variable reluctance motors 300 may not afford adequate detent torque and thus a solenoid 301 inserts a spring-activated 315 plunger tip 304 between the teeth of the first small gear 303 to lock-in detent and sustain torque against stops 305 when the solenoid 301 coil 314 has no current 313 flowing. Such an embodiment proceeds in actuating a control mechanism first by driving current 313 in the direction shown per the right hand rule causing the solenoid 301 coil 314 to unlock the gear 303 , then driving current 317 in the motor winding 316 , to initiate rotation 318 translated through rotation 319 to rotation 320 or 320 A to rotate a rudder or rotate a sail boom. Once actuation completes, the solenoid 301 coil 314 no longer conducts current, returning the solenoid 301 plunger tip 304 to the locked position. All such control algorithm steps thus have their own unique SCADA object tag definitions. As PLC's 200 have traditionally evolved from industrial process applications including SCADA systems control software, portability of Computer Numeric Controlled (CNC) G-code for servo-motors 300 , and servo mechanisms such as mechanical lead screw, or ball screw systems analogous to worm drive systems enable preferred embodiments of control actuators in the present invention. One must note that partial implementations or minor deviations known by one of ordinary skill in the art of any of the exemplary embodiments of the aforementioned control actuator electromechanical circuits do not represent a departure from the scope or spirit of the present invention. FIG. 4 illustrates the visual representations that appear on the Graphical User Interface (GUI) 400 of one or plural client workstations 209 at the central service facility 102 , and illustrates how a human can affect the behavior of exemplary SCADA algorithms. The foregoing exemplary SCADA algorithms run on one or plural server 204 processing systems including a GIS that performs all the data collection, processing, storage, analyses and navigation vector determinations accessible through the GUI 400 on one or plural client workstations 209 . Three different workstations 209 A, B, or C displaying information pertaining to one or plural mobile structures 100 , or one workstation displaying three different GUI's 400 at different times, at one time displaying the GUI 400 of workstation 209 A, at another time the GUI 400 of workstation 209 B, and at another time the GUI 400 of workstation 209 C operate at the central service facility 102 . Using typical computer pointing and data entry hardware, a human operating the workstation 209 may interact with the GUI 400 to invoke any of the GUI's 400 on any of the workstations 209 A, B, or C as shown in FIG. 4 . The GUI 400 of workstation 209 A displays position, heading, velocity, and points of sail for the mobile structure 100 in the process of energy extraction in a sailing vessel embodiment. Vessel icon 401 graphically shows direction of the mobile structure 100 relative to true north given by the compass icon 405 . GPS field 402 numerically provides vessel instantaneous location, velocity, and heading. Sail icon 403 and rudder icon 404 along with surface true wind data 406 begotten from various aforementioned weather data. Sources 108 , or empirically derived from GPS 202 and aerovane sensor 201 data as previously described permits observation and control of the points of sail of the mobile structure 100 in a sailing vessel embodiment. Obviously, in a propelled embodiment, a propeller icon serves analogous functions as the sail icon 403 . Pointing and data entry hardware on the workstation 209 A allows a human operator to point and select the aforementioned icons and data fields to alter visual representations and alter instantaneous control of the mobile structure 100 . For instance, if a human operator points and selects vessel icon 401 , sail icon 403 , or rudder icon 404 , the operator may view a alphanumerical field indicating points of sail using nautical terms such as “Beam Reach” to describe that point of sail shown on the display of workstation 209 A. At this point, the GUI 400 can numerically give displacement angles of the boom and the rudder with an option to the human operator to manually change these values, override auto-navigation, and actuate rotation of the boom or rudder on the mobile structure 100 as previously described. Herein the GUI 400 , the preferred SCADA algorithm invokes performance models for the mobile structure 100 to estimate or forecast energy efficiency thereof, using a Velocity Prediction Program (VPP) performing Computational Fluid Dynamics (CFD) calculations on the sailing vessel along with its energy extracting appendage. The GUI 400 at this point also suggests for instance, a “Broad Reach” point of sail given prevailing wind and optimal least-cost or highest yield path analysis inputs. Selecting the vessel icon 401 also permits the human operator to monitor, adjust, and receive performance predictions based on turbine gate openness and fuel tank fullness affecting the overall drag on the mobile structure 100 , given the VPP performing CFD calculations on the modeled energy extracting turbine appendage. Note for a preferred SCADA algorithm of the present invention, the sailing vessel VPP will output data tabulating generated power, instead of velocity for typical prior art VPP's, for the given true wind speed, turbine gate openness, fuel tank fullness, and heading, along with the accompanying points of sail and control settings. Obviously, an exemplary SCADA algorithm performs an analogous propeller performance VPP and least-cost path analysis for a propelled mobile structure 103 , 104 during these GUI 400 operations. Selecting the GPS field 402 allows the human operator to change viewing options such as converting units of parameters such as position, changing the Universal Transverse Mercator (UTM) kilometer units to miles or to degrees, minutes, seconds of longitude and latitude; velocity, knots to kilometers per hour or miles per hour; or time, from Coordinated Universal Time (UTC) to local time. Selecting the GPS field 402 for a propelled embodiment of mobile structure 103 , 104 allows for manually changing propeller rotational speed. Selecting the compass icon 405 or the true wind data 406 allows the viewing orientation angle of the vessel icon 401 to move relative to the compass icon 405 or true wind data 406 , respectively. The GUI 400 of workstation 209 B in FIG. 4 illustrates a virtual reality representation 407 , along with the attitude of the vessel, listing and heel angle, or to borrow aviation terms, roll and pitch, respectively, for the mobile structure 100 in the process of energy extraction. The virtual reality rendering 407 indicates a downward or plunging heel angle or pitch, and a port listing or roll. Had the vessel assumed an upward or breaching heel angle, the rendering 407 would display the deck instead of the hull as indicated in the rendering 407 . If the mobile structure 100 sensors include a video camera data stream, actual oceanic surface in the vicinity the vessel will display in this GUI 400 frame. The view parallel 408 to the direction of travel further displays the port listing coordinated with the rendering 407 , along with the angle of listing 409 . A starboard listing or roll would result in an angle 409 in the opposite direction. The view perpendicular 410 to the direction of travel further displays the plunging or downward heel or pitch, coordinated with the rendering 407 and displaying the heel angle 411 . Likewise, a breaching or upward pitch would result in the heel angle 411 displayed in opposite direction. Selecting the virtual reality 407 icon allows for changing the camera angle. Selecting the listing angle 409 icon or the heel angle 411 icon allows the human operator to manually set the threshold for a broach warning and associated control. The GUI 400 of workstation 209 C in FIG. 4 illustrates a weather map with path analysis lines 417 , 418 , 419 for the mobile structure 100 operating in the weather pattern 101 . Browsing the GUI 400 of workstation 209 C initiates a least-cost and highest yield path analysis whereby a weather semivariogram accounting for spatial structure including land mass 109 or seamounts 109 , global trends and anisotropy, air temperature, water temperature, wind direction, wind speed, and wave data forms a basis for mapping predictive costs, or yields in the case of energy extraction. From the predictive map, the preferred SCADA algorithm assigns weights that average over suggested routes 417 , 418 , 419 based on path length in a weighted cost or yield raster. In the GUI 400 of workstation 209 C, each concentric closed surface 413 , 414 , 415 represents areas of increasing wind and surge current energy inward to the eye 416 for a given weather pattern 101 . While a global trend may indicate a greater degree of symmetry and counterclockwise, in this example northern hemispheric, vortex trend as in the FIG. 1 representation of the weather pattern 101 , anisotropy caused by land 109 mass or seamount 109 and other stochastic modeled factors such as air temperature, water temperature, wind direction, wind speed, and wave data result in a probabilistic field that the semivariogram 413 , 414 , 415 represents. From this probability field, weather prediction analysis can predict a path 412 for the storm that further affects the least-cost or highest yield analysis. Note that in the GUI 400 of workstation 209 C, the concentric closed surfaces 413 , 414 , 415 can selectively represent semivariogram values or else predictive energy regions, also known as a cost raster for non-energy extracting vessel logistics or a yield raster when referring to energy extraction. The preferred embodiment also includes an advanced physical object 109 detection, identification and avoidance system that remotely utilizes the integrated sensors including but not limited to on-board radar and sonar systems to perform sweeping remotely sensed anomalies returns. A preferred SCADA algorithm then compares the signatures of these electromagnetic energy returns against known libraries of predefined physical objects 109 based on size, shape, rate of movement and other characteristics to identify possible type of physical object 109 feature detected. Optionally, an exemplary algorithm further correlates the signatures against a video camera data stream for further classification and confirmation of the physical object 109 . A preferred SCADA algorithm then invariably correlates the identified physical object 109 spatially against the vessel's 100 , 102 , 103 , 104 current location, path and velocity in order to assess the need for altering the vessel's 100 , 102 , 103 , 104 course to initiate avoidance and altered path routing and associated cost accounting. A preferred SCADA algorithm then indexes the identified physical object 109 in the algorithmic path controls to include avoidance or least cost path towards the physical object 109 depending on predetermined logic and/or human operator interaction. A preferred SCADA algorithm of the present invention thereby further accounts for VPP modeling of the mobile structure 100 when assigning weights that average over a path 417 , 418 , 419 based on direction and length in a weighted anisotropic energy yield raster. Depending on the cost or yield goal, the highest yield algorithm may select a path 417 or 418 , yielding the highest energy in the shortest time with least risk to structural harm to the mobile structure 100 , while the least-cost algorithm yields the shortest logistical trajectory with least risk to structural harm to an offshore embodiment of the central service facility 102 , a non-energy extracting vessel. Selecting the path lines 417 , 418 , 419 allows the human operator to optionally choose mission critical navigation parameters such as cost and yield weights and cost or yield goals. For all the aforementioned GUI 400 icons and data fields, a SCADA object tag definition exists for accessing the aforementioned data structures and evoking the aforementioned control. Object tags allow for structured programming techniques facilitating manageability and sustainability of a substantially large code base traversing multiple software application layer interfaces from the workstations 209 , to the server 204 and from the server 204 to the PLC's 200 , and from the server 204 to the one or plural of many possible entities including those accessible through the Internet from where all weather data in this exemplary embodiment disseminates, such as from the National Weather Service 108 . Functional differences within the GUI 400 for workstations 209 A, B, or C clearly do not present a substantial departure from the scope and spirit of the present invention. From the preceding description of the present invention, this specification manifests various techniques for use in implementing the concepts of the present invention without departing from its scope. Furthermore, while this specification describes the present invention with specific reference to certain embodiments, a person of ordinary skill in the art would recognize that one could make changes in form and detail without departing from the scope and the spirit of the invention. This specification presented embodiments in all respects as illustrative and not restrictive. All parties must understand that this specification does not limited the present invention to the previously described particular embodiments, but asserts the present invention's capability of many rearrangements, modifications, omissions, and substitutions without departing from its scope. Thus, a supervisory control and data acquisition system for energy extracting vessel navigation has been described.

A Supervisory Control And Data Acquisition (SCADA) system guides navigation of a vessel enabled to extract energy from wind and/or water currents primarily in offshore marine environments. An exemplary SCADA system could embody server and client software applications running on microprocessor systems at a remote control central service logging and energy distribution facility, and the vessel itself. The remote control service facility runs Human Machine Interface (HMI) software in the form of a Graphical User Interface (GUI) allowing choices to maximize system performance. The central server accesses information to control vessel position based on transmitted Global Position Satellite (GPS) data from the vessel, and weather information from the Geographic Information System (GIS) provided by multiple spatial temporal data sources. A server-side optimization algorithm fed the parameters delivered from vessel aerodynamic/hydrodynamic performance simulation software models, the vessel onboard sensor data, and integrated real-time weather and environmental data determines an optimal navigation through weather systems and presents choices to the HMI.

big_patent

FIELD OF THE INVENTION [0001] The invention relates to a rolling body guide cage which is produced as such under the influence of forming production steps from at least one ring element and several guide structures arranged in succession in the circumferential direction and in each case provided to guide rolling bodies. The invention furthermore also relates to a method for manufacturing such a rolling body guide cage. BACKGROUND [0002] DE 1 625 540 A1 discloses a ball bearing cage which is composed of two axially profiled ring elements. The two ring elements are of identical design and are axially profiled in such a manner that they form spherical cap pockets which are arranged in succession in the circumferential direction and which are connected in each case via bridge portions. The two ring elements are composed in such a manner that they contact one another via their bridge portions, wherein the in each case corresponding spherical cap pockets which face one another then jointly form ball guide pockets into which in each case a ball can be inserted. The two ring elements which contact one another via the bridge portions are welded to one another in the region of the bridge portions by spot weld points. In order to manufacture the ring elements, these are punched out from a sheet metal material and formed in a forming tool such that they obtain the axial profiling required to form the ball guide pockets. [0003] It is disadvantageous in the case of this ball bearing cage that a relatively large amount of waste material is generated when punching out the ring elements from the sheet metal material. SUMMARY [0004] Proceeding from the disadvantages set out of the known prior art, the object on which the invention is based is therefore to indicate solutions by means of which it is possible to reduce the production costs which arise during manufacture of rolling body guide cages. [0005] According to the invention, this object is achieved by a rolling body guide cage with a ring element which is produced from a sheet metal material and has an axial profiling formed by forming techniques and several rolling body guide structures which are arranged in succession in the circumferential direction, the ring element being composed of at least two flat material ring segments which are joined to one another in succession in the circumferential direction and are connected, in particular welded, to one another in a production step which precedes the formation of the axial profiling. [0006] As a result of this, it is advantageously possible to significantly reduce the cutting waste in the manufacture of rolling body guide cages produced by forming techniques in a manner which can be achieved at relatively low-cost from a process engineering perspective. The invention has been shown to be particularly advantageous in particular in the manufacture of rolling body guide cages with an internal diameter of more than 140 mm since the process costs associated with the formation of three weld joints are, at this diameter, already substantially below the material costs of the cutting waste which has hitherto arisen. [0007] According to one particularly preferred embodiment of the invention, the flat material ring segments placed in succession with one another in the circumferential direction are put together across an engagement zone and in this engagement zone are welded along edge regions which face one other therein. The flat material ring segments are connected to one another according to a particular aspect of the present invention in the region of the engagement zones across positively engaging joint contours. These joint contours form an undercut geometry which as such preliminarily couples the ring elements to one another in the circumferential direction. The geometric profile of the joint contours is preferably selected such that adequate coupling of the ring segments is produced with as short as possible a weld seam length. The joint contours are furthermore preferably configured such that the weld seams taper both towards the ring element inner circumferential edge and towards the ring element outer circumferential edge with as obtuse an angle as possible. [0008] The flat material ring segments are cut out, in particular, punched out according to the invention from a sheet metal material. A relatively high material saving can be achieved according to the invention in that the flat material ring segments are formed as 120° ring segments. Only three weld points are then required for joining together a ring element from such flat material ring segments. The 120° segments can be punched out in close succession from a sheet metal strip. In the case of this punching-out step, the circular arc-like inner and outer edges as well as the joint geometries can be cut out in one step. [0009] The concept according to the invention of the production of the rolling body guide cage from a welded ring segment is suitable both for the manufacture of radial bearing cages and for the manufacture of axial bearing cages, in particular cages of groove and angular ball bearings. Particularly in the case of the manufacture of rolling body guide cages for groove and angular ball bearings, the rolling body guide cage can be structured such that it is composed of a first ring element and a structurally identical second ring element positioned in mirror-symmetry. The per se structurally identical ring elements are preferably put together in such a manner that the weld points formed between the ring segments of the ring elements of both ring elements are offset with respect to one another in the circumferential direction, i.e. a weld point is overlapped by an unwelded point. [0010] In terms of the method, the object indicated above is also achieved according to the invention by a method for manufacturing a rolling body guide cage from a ring element which is produced from a sheet metal material and obtains an axial profiling in the context of a forming step, wherein the rolling body guide cage forms several rolling body guide structures arranged in succession in the circumferential direction and wherein, in the context of a method step which precedes the forming step, the ring element is composed of at least two flat material ring segments which are joined to one another in succession in the circumferential direction. [0011] According to a particularly preferred embodiment of the method according to the invention, these flat material ring segments are welded to one another in the region of a joint formed by these flat material ring segments. [0012] The formation of the weld point is preferably performed by laser welding. As a result of this, a high-strength weld point is produced with a low degree of welding distortion. Alternatively to this, it is also possible to this end to form the weld point as a pressure welding point. To this end, it is possible to retain local accumulations of material in the region of the weld point which are formed, for example, by bead portions which can be generated when punching out the ring elements. [0013] The ring segments can be produced in such a manner that they initially have a slight oversize and are initially further cut and where necessary calibrated after welding in the context of a contouring step. However, the ring segments can in principle also be cut to their final dimensions in terms of their material width and are subsequently only formed and where necessary punched internally. [0014] It is possible to punch out the ring segment from a sufficiently wide strip material and thereby push by means of the punching die directly into a positioning device, for example an annular groove of a rotary plate. The rotary plate is pivoted by a corresponding degree of angle of e.g. 120° after insertion of the ring segment and the next ring segment is punched out from the strip material and pushed back into the annular groove of the rotary plate, wherein said ring segment comes into engagement with the connection geometry of the ring element which already lies in the annular groove. After a further rotation of the rotary plate, the third ring segment is punched from strip material and is inserted into the free annular groove portion, wherein said ring segment now comes into engagement with the two ring elements which already lie in the annular groove. Even prior to the introduction of the third ring segment, the ring segments already located in the annular groove can be welded in the rotary plate. After the third ring segment has been inserted and thus a complete ring element lies in the annular groove, the two remaining weld points can be formed. The finished welded ring element is then ejected from the annular groove of the rotary plate and the process is continued again. The punching and welding steps can be carried out such that these overlap chronologically. During the formation of the last two weld points on the respective ring element, strip material can be supplied and where necessary also be punched, wherein the ring segment formed in this manner is moved into the annular groove either only after emptying of the rotary plate or a further rotary plate is supplied. The welding is preferably carried out by a laser beam guided in a path-controlled manner. The welding can where necessary be carried out with the addition of welding material, in particular via a welding wire. The weld seam is, however, preferably formed by only local fusing of the material along the joint edges. [0015] It is thus possible to still join together the ring segments in the context of the workpiece movement to be attributed to the punching process to form a ring segment. In the context of this joining process, the ring segments can also initially be put together only positively in the rotary plate and then lifted out of the rotary plate and moved as prejoined ring elements into a welding station. [0016] It is furthermore possible to join together the initially punched out or otherwise cut out ring segments with alignment of the edges to form a stack or ring segment block and then supply this to a welding station in which the ring segments are inserted, for example, again into an annular groove of a rotary plate and thereby come into engagement with one another via their head and tail geometries. [0017] A particularly high-quality design of the weld connection points can be achieved in that, prior to the punching out of the ring segment or during punching out, a material bead close to the edge is generated which then provides in the context of carrying out the welding process a material volume which enables a complete filling out of the weld seam so that no chamfer is formed in the region of the weld point or any other cross-sectional weakening is produced. BRIEF DESCRIPTION OF THE DRAWINGS [0018] The rolling body guide cage formed according to the invention is explained in greater detail below in several preferred embodiments with reference to the enclosed drawings. In these drawings: [0019] FIG. 1 shows a sketch in order to illustrate a ring element used according to the invention to form a rolling body guide cage, which ring element is composed of several ring segments which are welded to one another; [0020] FIG. 2 shows a sketch in order to illustrate the structure of a ring segment used to form the ring element according to FIG. 1 ; [0021] FIG. 3 shows a perspective illustration of a cage part, which is produced in the context of a forming step from a ring element according to FIG. 1 , of a two-part ball bearing cage; [0022] FIG. 4 shows a perspective illustration of an axial needle bearing cage which is produced in the context of a forming step from a ring element according to FIG. 1 ; [0023] FIG. 5 shows a perspective illustration of a cage, which is produced in the context of a forming step from a ring element according to FIG. 1 , for an axial ball roller bearing; [0024] FIG. 6 shows a sketch in order to illustrate a further variant of the joint contour produced, preferably welded over between two ring segments; [0025] FIG. 7 shows a sketch in order to illustrate an exemplary embodiment in which an accumulation of material is formed along the edges to be welded by plastic forming; [0026] FIG. 8 a shows a first sketch in order to illustrate an exemplary embodiment in which, by local plastic forming, axial securing of the ring segments which are positively interlocked in one another in the circumferential direction can also be achieved; [0027] FIG. 8 b shows a second sketch in order to illustrate an exemplary embodiment in which, by local plastic forming, axial securing of the ring segments which are positively interlocked in one another in the circumferential direction can also be achieved; [0028] FIG. 9 shows a sketch in order to illustrate the cut position of the ring segments punched out according to the invention from a strip material in order to form a joined together ring element for a rolling body guide cage. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0029] FIG. 1 shows in the form of a top view a ring element which as such is further processed in the context of the following working steps, in particular a forming step to form a rolling body guide cage, wherein the ring element then in the context of the forming step obtains an axial profiling and in general a geometry in which it forms several rolling body guide structures arranged in succession in the circumferential direction. [0030] The ring element shown here is produced from a sheet metal material and is composed of at least three flat material ring segments S 1 , S 2 , S 3 which are joined to one another in succession in the circumferential direction. Said flat material ring segments S 1 , S 2 , S 3 are joined together and here furthermore welded together via joints F 1 , F 2 , F 3 . [0031] Flat material ring segments S 1 , S 2 , S 3 which are apparent here and which are placed in succession with one another in the circumferential direction are welded along the edge regions which face one another within joints F 1 , F 2 , F 3 . Flat material ring segments S 1 , S 2 , S 3 are configured in the region of joints F 1 , F 2 , F 3 such that said joints F 1 , F 2 , F 3 form engagement zones within which flat material ring segments S 1 , S 2 , S 3 are connected to one another via joint contours which engage positively in one another. These joint contours form, as is apparent here, an undercut geometry which as such at least preliminarily couples flat material ring segments S 1 , S 2 , S 3 to one another in the circumferential direction. The geometric profile of the joint contours is concretely selected here so that adequate coupling of flat material ring segments S 1 , S 2 , S 3 is produced. [0032] FIG. 2 illustrates the structure and the component geometry of an individual flat material ring segment S 1 . Flat material ring segment S 1 is cut out from a sheet metal material in such a manner that this ring segment forms a 120° ring segment. Only three weld points are required for joining together a ring element composed of such flat material ring segments, as is apparent in FIG. 1 . The 120° segments can be punched out from a sheet metal strip in close superficial succession. In the case of this punching out step, the circular arc-like inner and outer edges and the joint geometries are cut out in one step. Flat material ring segment S 1 forms a head portion S 1 K and a head insert portion S 1 E. The outer contour of head portion S 1 K and the inner contour of the head insert portion are matched to one another so that both flat material ring segments sit in one another under slight elastic tension during insertion of head portion S 1 K of an adjoining flat material ring segment into head insert portion S 1 E. In so far as the joined together flat material ring segments are welded, it is possible to begin with the formation of the weld seam at a point which makes it possible that, during the weld seam formation, the ring segments to be connected to one another come closer to one another as a result of elastic pretensioning or also as a result of thermal influences. The pretensioning can also be selected such that it prevents a thermal moving part of the edge regions to be welded. In the case of the exemplary embodiment shown here, it is in particular possible to begin with the formation of the weld seam at the inner region of the joint contour, i.e. at the edge of tongue tip Z of the head portion, and form the weld seam in two steps from the inner region towards the outer or inner edge of the ring element. [0033] FIG. 3 shows a ring element for a rolling body guide cage which is produced by forming from a composed ring element according to FIG. 1 . Weld points W 1 , W 2 , W 3 are indicated in the ring element shown here, along which weld points W 1 , W 2 , W 3 individual ring segments S 1 , S 2 , S 3 are welded to one another in a forming step which precedes the plastic forming. This ring element is put together with a further ring element of an identical design to form a cage for a groove ball bearing. The ring element shown here forms several spherical cap pockets K which are arranged in succession in the circumferential direction and then form ball guide pockets in interaction with a ring element of identical design arranged in mirror-symmetry. The connection of the two combined ring elements can be carried out depending on the design of the ball bearing before or also only after the insertion of the balls into the path space formed between bearing inner ring and bearing outer ring. In the case of a groove ball bearing, the connection of the two ring elements is typically only carried out after insertion of the balls into the path space. [0034] FIG. 4 shows a further embodiment of a ring element according to the invention for a rolling body guide cage which is produced in a similar manner to the variant according to FIG. 3 by forming from a combined ring element according to FIG. 1 . In the ring element shown here, weld points W 1 , W 2 , W 3 are in turn indicated along which individual ring segments S 1 , S 2 , S 3 are welded to one another in a forming step which precedes plastic forming. The rolling body guide cage shown here is formed as an axial cylinder roller guide cage. This rolling body guide cage forms several rolling body guide windows F which are arranged in succession in the circumferential direction and are separated from one another by guide webs B. Guide webs B are axially profiled and form a middle stage B 1 and connecting bridges B 2 , B 3 . Outer edge region R 1 of the rolling body guide cage forms an angle profile in the axial section. Inner edge region R 2 of the rolling body guide cage also forms an angle profile in the axial section. It is possible, by forming, to enclose an additional wire ring element in the inner and/or outer edge region R 1 , R 2 of the ring element, which wire ring element increases the mechanical strength of the ring element, in particular also in the region of weld points W 1 , W 2 , W 3 . [0035] FIG. 5 shows a third embodiment of a ring element according to the invention for a rolling body guide cage which is produced in a similar manner to the variants according to FIGS. 3 and 4 also by forming from a combined ring element according to FIG. 1 . In the ring element shown here, weld points W 1 , W 2 , W 3 are in turn indicated along which individual ring segments S 1 , S 2 , S 3 are welded to one another in a forming step which precedes plastic forming. The rolling body guide cage shown here is formed here as a ball guide cage for an axial ball bearing. This ball guide cage forms several rolling body guide windows F which are arranged in succession in the circumferential direction and are in turn separated from one another by guide webs B. Rolling body guide windows F are punched into the ring element formed by forming techniques in a machining step which follows the forming. Outer edge region R 1 of the ball guide cage forms, in a similar manner to the variant according to FIG. 4 , an angle profile in the axial section. Inner edge region R 2 of the rolling body guide cage also forms an angle profile in the axial section. It is also possible here, by forming, to enclose an additional wire ring element in inner and/or outer edge region R 1 , R 2 of the ring element, which wire ring element increases the mechanical strength of the cage and bridges weld points W 1 , W 2 , W 3 . FIG. 6 illustrates, in the form of a top view of a portion of a ring element, an alternative joint contour by which two ring segments S 1 , S 2 arranged in succession can be connected to one another. This contour is characterized by a small widening of the gap during the welding process and requires a small amount of material in the circumferential direction. The joint contour forms two engagement tongues Z 1 , Z 2 which are anchored positively in a corresponding complementary contour. The run-out of the joint edges to the inner or outer edge is relatively obtuse, it being almost 90° here. [0036] FIG. 7 illustrates in the form of a cross-sectional sketch how, by forming beads 2 , 3 on the sheet metal material, a certain degree of material accumulation can be retained which makes it possible, after fusing thereof, in particular by laser welding, to generate a substantially flat weld point. Beads 2 , 3 can be formed in the context of the punching process or a preceding embossing step by plastic material forming. [0037] FIGS. 8 a and 8 b also illustrate in the form of a cross-sectional sketch how axial securing of ring segments S 1 , S 2 can be achieved by local material forming. Beads 2 a, 2 b can be formed, for example, along head edge K 1 of ring segment S 1 by a preceding embossing step and in each case depressions 3 a, 3 b can be formed at foot edge F 2 of adjoining ring segment S 2 . After joining together of ring segments S 1 , S 2 , beads 2 a, 2 b are rolled over and deformed into the state shown in FIG. 8 b . In this state, both ring segments S 1 , S 2 are axially secured with respect to one another. The connection point formed in this manner can where necessary be welded over. [0038] FIG. 9 shows by way of example how a ring segment S 1 can be punched out of a strip material SM in close succession. Punched out ring segments can joined together directly after the punching step to form a ring element and then welded. In the case of the exemplary embodiment shown here, ring segment S 1 forms a segment angle W of 120°. In so far as the ring element is formed from three segments S 1 punched out from strip material SM in direct succession, it is ensured that substantially the same material properties are ensured within a ring element. This is particularly advantageous for a uniform formation of the weld points. LIST OF REFERENCE NUMBERS 2 a Bead 2 b Bead 3 a Depression 3 b Depression B Guide web [0039] B 2 Connecting bridge B 3 Connecting bridge F 1 Joint F 2 Joint F 3 Joint [0040] K Spherical cap pocket K 1 Head edge R 1 Outer edge region R 2 Inner edge region Flat material ring segment S 2 Flat material ring segment S 3 Flat material ring segment S 1 K Head portion S 1 E Head insert portion W Segment angle W 1 Weld points W 2 Weld points W 3 Weld points SM Strip material

A rolling element guide cage having a ring element which is made from a sheet material and has an axial profiling produced using forming techniques and forms a plurality of successive rolling element guide structures in the circumferential direction. The ring element is composed of at least two flat material ring segments joined to one another successively in the circumferential direction, said segments being joined together in a manufacturing step which precedes the formation of the axial profiling.

big_patent

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This is a continuation of application Ser. No. 10/445,861 filed May 27, 2003, which is a continuation of application Ser. No. 10/032,853 filed Oct. 25, 2001 and now U.S. Pat. No. 6,772,064. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present methods and systems generally relate to processing and transmitting information to facilitate providing service in a telecommunications network. The methods and systems discussed herein more particularly relate to use of global satellite positioning to facilitate processing and transmission of information associated with telecommunications service locations and routing travel between more than one such service location. [0004] 2. Description of the Related Art [0005] Efficient and effective customer service is an essential requirement for commercial enterprises to compete successfully in today's business world. In the telecommunications industry, for example, providing customer service is an important part of sustaining market share in view of the many competitors in the industry. Customers whose telephone service, for example, is interrupted or disconnected for even a relatively short period of time may desire to seek an alternative source for service, especially if the interruption or disconnection is not addressed by a quick and effective customer service response. [0006] One important aspect of providing customer service is maintaining accurate and complete knowledge of the customer's location. Computer systems and databases that provide customer addresses often only provide vague references, however, to the exact location of the customer. Such customer addresses typically do not include information of sufficient specificity to permit efficient identification of a service location associated with the customer. In the context of a technician transporting a vehicle to a customer's service location, for example, this lack of sufficient service location information can generate excessive driving time and slow response time. Where the response time is unacceptably high, the lack of sufficient service location information can result in delayed or missed customer commitments. It can be appreciated that such delayed or missed customer commitments can cause a commercial enterprise to lose valuable customers. [0007] What are needed, therefore, are methods and systems for acquiring information associated with a customer's service location. Such methods and systems are needed to obtain, for example, a latitude and longitude associated with the customer's service location. In one aspect, if latitude and longitude information could be collected by a service technician when the customer's service location is visited, those coordinates could then be used to find the customer at a later date. Moreover, if latitude and longitude coordinates could be made available in a database associated with that specific customer, the coordinates could be used to assist in determining the service location of that customer. Such service location information could permit a service technician to drive directly to the customer service location with little or no time lost searching for the service location. [0008] What are also needed are methods and systems for providing a service technician with directions, such as driving directions between two or more service locations. Such directions could be employed to route travel from a first customer service location to a second customer service location. It can be seen that such directions would further reduce the possibility of error in locating a customer service location and thereby enhance customer service response time. SUMMARY [0009] Methods and systems are provided for obtaining information related to a customer service location. One embodiment of the method includes requesting at least one set of coordinates associated with the customer service location; accessing a technician server to direct a global satellite positioning system to obtain the set of coordinates for the customer service location; obtaining the coordinates and updating one or more databases with the coordinates. The coordinates may include at least one of a latitude and a longitude associated with the customer service location. One embodiment of a system for obtaining information related to a customer service location includes an input device configured for use by a service technician at the customer service location. A technician server is included in the system for receiving data transmissions from the input device. The technician server is in communication with a global positioning satellite system for determining a set of coordinates associated with the input device. Computer-readable media embodiments are also presented in connection with these methods and systems. [0010] In addition, methods and systems are discussed herein for generating directions for a service technician traveling from a first customer service location to at least a second customer service location. One embodiment of the method includes obtaining through a technician server at least one set of “from” coordinates associated with the first customer service location and at least one set of “to” coordinates associated with the second customer location; transmitting the “from” and “to” coordinates to a mapping system; and, generating directions in the mapping system based on the “to” and the “from” coordinates. One system embodiment includes an input device configured for use by a service technician at a first customer service location. A technician server is provided for receiving data transmissions from the input device. A global positioning satellite system, which is configured for determining at least one set of “from” coordinates associated with the input device is provided for use on an as needed basis. At least one database is included in the system for storing a “to” set of coordinates associated with the second customer service location and the “from” set of coordinates. The system further includes a mapping system operatively associated with the input device for generating travel directions based on the “from” and “to” coordinates. At least one of the sets of coordinates includes latitude and a longitude data. Computer-readable media embodiments of these methods and systems are also provided. BRIEF DESCRIPTION OF THE FIGURES [0011] FIG. 1 is a schematic diagram depicting one embodiment of a system for obtaining, processing, and transmitting information related to providing customer service at a customer service location; [0012] FIG. 2 is a schematic diagram depicting a portion of the system of FIG. 1 in more detail; [0013] FIG. 3 is a process flow diagram showing one embodiment of a method for obtaining, transmitting and processing information related to providing service at a customer service location; [0014] FIG. 4 is a schematic diagram depicting one embodiment of a system for obtaining, processing, and transmitting information related to providing customer service at a customer service location; and, [0015] FIG. 5 is a progress flow diagram depicting one embodiment of a method for obtaining, processing, and transmitting information related to providing customer service at a customer service location. DETAILED DESCRIPTION [0016] Referring now to FIGS. 1 and 2 , a service technician visiting a customer service location is provided with a technician input device 2 for receiving and transmitting information related to a disruption or interruption of service at the service location. The input device 2 can be a wireless PC, for example, a laptop, a personal digital assistant (PDA), a wireless pager or any other device suitable for receiving and transmitting data associated with providing service at the customer service location. A transponder system 4 is operatively associated with the input device 2 for receiving and transmitting signals such as satellite transmission signals, for example. [0017] The input device 2 is configured and programmed to permit the service technician to access a technician server 6 . As shown in FIG. 1 , access to the technician server 6 can be enabled through a wireless data network 8 through a radio connection 10 . Access to the technician server can also be enabled by a modem connection 12 through a landline server 14 . The landline server 14 can be a server configured in accordance with a server having a CSX 7000 trade designation employed by BellSouth Telecommunications (BST —Atlanta, Ga.). [0018] A protocol server 16 receives and processes communications from both the wireless data network 8 and the landline server 14 . In operation of the input device 2 , the protocol server 16 processes information transmitted from the input device 2 including, for example, a user ID, a password, a radio serial number, an input device serial number, and other similar data associated with a service technician and service provided at a customer service location. In one aspect, the protocol server 16 can include one or more WINDOWS NT servers (Microsoft Corporation) configured to assign one or more logical ports to transmissions received from the input device 2 . [0019] In one aspect of the present methods and systems, the technician server 6 can be a server having a TECHACCESS trade designation (Telcordia Technologies). The technician server 6 can be a conventional server configured and programmed to verify and/or process information received from the input device 2 . The technician server 6 functions as a transaction request broker between the protocol server 16 and one or more other systems operatively connected to the technician server 6 . The systems operatively associated with the technician server 6 can include, among other possible systems, a global positioning satellite system 18 (GPS system), a dispatch system 20 , an address guide system 22 , and a customer records system 24 . [0020] In one embodiment of the present methods and systems, the GPS system 18 can be configured in accordance with the BellSouth Telecommunications Global Positioning Satellite System (GPS) as implemented by SAIC's Wireless Systems Group (WSG). The GPS system 18 is operatively associated with the transponder system 4 and can be employed to track, dispatch, and monitor service technicians and their input devices at numerous customer service locations. In one aspect, the GPS system 18 interacts with a transponder mounted on a mobile vehicle (not shown) employed by the service technician at a customer service location. [0021] One purpose of the GPS System 18 is to provide supervisors and managers of service technicians with more comprehensive technician activity information. The GPS system 18 can include one or more servers (not shown) and one or more databases (not shown) for transmitting, receiving and storing data associated with satellite communications. In the context of the present methods and systems, the GPS system 18 serves to acquire information associated with a customer service location including, for example, the latitude and longitude coordinates of the customer service location. [0022] The dispatch system 20 serves to receive, process and transmit information related to service required at one or more customer service locations. In one embodiment, the dispatch system 20 includes a server, a database and one or more graphical interfaces for receiving commands from a user. Such commands can include, for example, entry on a graphical user interface (GUI) of customer information and a problem description associated with a particular interruption or disruption of service. The dispatch system 20 communicates with the technician server 6 to process and transmit information related to actions to be performed at a customer service location. Examples of dispatch systems suitable for use in connection with the present methods and systems include the “LMOS,” “IDS” and “WAFA” systems of BellSouth Telecommunications. [0023] The address guide system 22 includes a database 26 for storing universal type address information, examples of which are shown in FIG. 2 . The address guide system 22 can be considered the keeper of all addresses in the universe of telecommunications services. The address guide system 22 helps to promote valid addresses as customer service locations. For example, if a customer contacts a telecommunications service provider, the customer can be queried for the customer's address. If the customer provides an address of 123 XYZ Street and there is no 123 XYZ Street in the database 26 of the address guide system 22 , then a correct address for the customer can be confirmed and entered into the database 26 . An example of an address guide system 22 suitable for use in accordance with the present methods and systems is the “RSAG” application of BellSouth Telecommunications. [0024] The customer record system 24 is operatively connected to the address guide system 22 and includes a database 28 for storing customer related information, examples of which are shown in FIG. 2 . In one embodiment of the present methods and systems, the customer record system 24 serves to store information related to a particular service location and customer. For example, when telephone service is initially requested by a customer, a record in the database 28 can be populated with information that will create a correspondence between the customer's address and the details of the telephone service to be installed. Records in the database 28 of the customer record system 24 typically remain effective as long as service at a particular address remains the same for that customer. The customer record system 24 interfaces with the dispatch system 20 during the operation of the dispatch system 20 to generate work orders associated with service issues at customer service locations. For example, if problems arise with a customer's service, such as the initial installation order for that service, the dispatch system 20 schedules the work order. The dispatch system 20 draws on information contained in the customer record system 24 to create the dispatch order for a service technician to perform any actions required by the work order. [0025] Referring now to FIGS. 1 through 3 , an operative example of the present methods and systems include a service technician at a customer service location with an input device 2 . In accordance with the connections described above, in step 32 the technician server 6 can request the coordinates, in terms of latitude and longitude, from the service technician at the customer service location. The request of step 32 can be performed, for example, in step 34 by a job closeout script application of the technician server 6 that is adapted to query the service technician regarding the customer's location at the conclusion of a service call. The technician server 6 may check to determine whether a latitude and longitude are already present in the customer's information in the database 28 of the customer record system 24 . [0026] The technician server 6 can then instruct the service technician in step 35 to verify his presence at the customer service location. In step 36 , the GPS system 18 is accessed, such as through a “Fleet Optimizer” application (BellSouth Technologies) associated with the technician server 6 , to obtain latitude and longitude coordinates derived from the location of the service technician's input device 2 . In step 38 , the GPS system 18 transmits a signal to the transponder system 4 operatively associated with the input device 2 and obtains coordinates of the customer service location in step 40 . The GPS system transmits the obtained coordinates to the technician server 6 in step 42 . In step 44 , the dispatch system 20 is updated with the newly obtained latitude and longitude information. In step 46 , the database 28 of the customer records system 24 is updated to reflect this latitude and longitude information. In step 48 , the latitude and longitude information is transmitted to and stored in the database 26 associated with the address guide system 22 . [0027] It can be seen that just because one has a street address for a customer service location, it does not necessarily follow that locating the customer service location can be readily performed. For example, a street address in Pittsburgh, Pa. might be Three Rivers Stadium Park. If this is the only information available, however, it may be difficult to find the customer service location where work needs to be performed. Use of a GPS system to associate coordinates with a street address permits one to know the position of a customer service location, and hence the location of a service technician performing work at that customer service location. [0028] In another example of the present methods and systems, a new customer requests service installation at ABC Street. Verification is performed to determine that ABC Street is a valid address. If it is a valid address, and if latitude and longitude information has been populated in the address guide system 22 , then the information can be used effectively by a service technician to address the customer's needs. In addition, if a service issue later arises with the customer service location, the dispatch system 20 can obtain the customer record, including the customer name, contact number, the type of facilities the customer has, and latitude and longitude information associated with the customer service location. This complete record of information provides enhanced response time for addressing the customer's service needs. [0029] Referring now to FIGS. 4 and 5 , in another aspect of the present methods and systems, a mapping system 52 can be provided for routing travel of a service technician between more than one customer service location. The mapping system 52 is configured and programmed to provide travel or routing directions to a service technician from a first location to at least a second location where customer service is to be performed. The mapping system 52 can include conventional mapping software installed on a computer-readable medium operatively associated with the input device. The mapping system 52 can also be accessed remotely, such as through a wireless connection between the mapping system 52 and the input device 2 . [0030] In one embodiment, the technician server 6 functions to provide latitude and longitude information to the mapping system 52 . This information includes “from” information (i.e., the origin customer service location of the service technician) and “to” information (i.e., the destination customer service location to where travel is desired for the service technician). Before dispatch to the next customer service location, the service technician requests driving instructions in step 62 . The technician server 6 queries the “Fleet Optimizer” application, or its functional equivalent, in step 64 to obtain the current customer service location in step 66 , which can be used by the mapping system 52 as the “from” location. If necessary, and in accordance with previous discussion of the present methods and systems, the GPS system 18 can be accessed to obtain “from” latitude and longitude coordinates in step 68 . [0031] The address guide system 22 can then be accessed by the technician server 6 in step 70 to provide the “to” location to the mapping system 52 , including latitude and longitude information for the destination customer service location. In step 72 , the technician server 6 transmits the “from” and “to” coordinates to the technician input device 2 . In step 74 , the mapping system 52 processes the “from” and “to” coordinates. The mapping system 52 can then generate and output driving directions from the “from” location to the “to” location for the service technician in step 76 . It can be appreciated that the output of the mapping system 52 including the driving directions can be in any conventional format suitable for communicating the directions to the service technician. For example, the output including the driving directions can be in electronic format or hard copy format. [0032] As discussed above, accurate latitude and longitude coordinates may have already been established for the present or origin customer service location. In the process of dispatching a service technician to a next customer service location, however, it may be necessary to engage the GPS system 18 to obtain these latitude and longitude coordinates. The GPS system 18 can therefore be employed to provide knowledge of one or more service technician locations for various customer service locations where service is required. The GPS system 18 also functions to promote providing correct customer service location information, including latitude and longitude coordinates associated with customer addresses and/or associated critical equipment. It can be seen that algorithms can be applied in the dispatch system 20 and/or the technician server 6 to use this knowledge of service technician whereabouts and customer service locations to facilitate moving the next best or available service technician to the next highest priority or most appropriate service location. [0033] The term “computer-readable medium” is defined herein as understood by those skilled in the art. A computer-readable medium can include, for example, memory devices such as diskettes, compact discs of both read-only and writeable varieties, optical disk drives, and hard disk drives. A computer-readable medium can also include memory storage that can be physical, virtual, permanent, temporary, semi-permanent and/or semi-temporary. A computer-readable medium can further include one or more data signals transmitted on one or more carrier waves. [0034] It can be appreciated that, in some embodiments of the present methods and systems disclosed herein, a single component can be replaced by multiple components, and multiple components replaced by a single component, to perform a given function. Except where such substitution would not be operative to practice the present methods and systems, such substitution is within the scope of the present invention. [0035] Examples presented herein are intended to illustrate potential implementations of the present communication method and system embodiments. It can be appreciated that such examples are intended primarily for purposes of illustration. No particular aspect or aspects of the example method and system embodiments, described herein are intended to limit the scope of the present invention. [0036] Whereas particular embodiments of the invention have been described herein for the purpose of illustrating the invention and not for the purpose of limiting the same, it can be appreciated by those of ordinary skill in the art that numerous variations of the details, materials and arrangement of parts may be made within the principle and scope of the invention without departing from the invention as described in the appended claims.

Methods and systems are provided for obtaining information related to a customer service location and directions for routing a service technician from one customer service location to another. One embodiment includes requesting at least one set of coordinates associated with the customer service location; accessing a technician server to direct a global satellite positioning system to obtain the set of coordinates for the customer service location; obtaining the coordinates and updating one or more databases with said coordinates. The coordinates may include at least one of a latitude and a longitude associated with the customer service location. Another embodiment includes obtaining through a technician server at least one set of “from” coordinates associated with the first customer service location and at least one set of “to” coordinates associated with the second customer location; transmitting the “from” and “to” coordinates to a mapping system; and, generating directions in the mapping system based on the “to” and “from” coordinates. At least one of the sets of coordinates includes latitude and longitude data. System and computer-readable media embodiments of these methods are also provided.

big_patent

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application claims benefit under 35 U.S.C. §119(a) of German Patent Application No. 10 2009 024 826.9-32, filed Jun. 13, 2009, the entire contents of which are incorporated herein by reference. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The invention relates generally to a system for compensating electromagnetic interfering fields, and in particular to a system for magnetic field compensation having two sensors and a digital processor. [0004] 2. Description of Related Art [0005] For compensating electromagnetic interfering fields, in particular magnetic interfering fields, feedback control systems are used in the very most cases, whereby one, or more sensors measure the amplitude of the interfering field for all three Cartesian space axes. The measuring signals of the sensors are fed to a control loop, which calculates control, or actuator signals from the measuring signals of the sensors, for devices generating magnetic fields. [0006] The magnetic field to be compensated may be the terrestrial magnetic field, or may be generated by other current-carrying devices being in the surrounding. [0007] Magnetic field compensation systems are for example used in connection with imaging systems using magnetic fields, for example in the case of scanning electron microscopes (SEM). [0008] In case of the mentioned devices for generating magnetic fields, it may be a matter of a current-carrying conductor, in the easiest case. Generally, one assumes interfering fields having far field characteristics, i.e. such fields, whose field amplitude does not essentially change within the range of 5 m. This assumption for example is true for interferences by rail vehicles. If the interfering fields are homogeneous in the range of interest, the compensation fields should be homogeneous, also. [0009] Pairs of so-called Helmholtz coils are preferably used for generating homogeneous compensation fields. At this, it is about two coils each being connected in the same direction, and having a distance to each other being equal to the half length of the edge (=coil diameter) (so-called Helmholtz condition). [0010] Furthermore, pairs of Helmholtz coils are used, whose distance to each other is equal to one length of the edge. If one pair of Helmholtz coils is used for each of the three space axes, the pairs of coils form a cube-shaped cage around the location, at which one, or more interfering fields shall be compensated. In case of such a coil arrangement, there indeed are field inhomogeneities in the interior of the cage, but these are acceptable in the most cases of application. [0011] A device for compensating magnetic fields is disclosed in U.S. Publication No 2005/019555A1 and has three coil pairs in a cage. The magnetic field to be compensated is measured and compensated, where an analog controller is used. [0012] Systems are also available, with which only one coil per space axis is used for generating the compensation field, however the compensation region, i.e. the region in which a good compensation is achieved, is considerably smaller than in the case of Helmholtz coils. [0013] Generally, one single magnetic field sensor is used for measuring the magnetic field at the place of interest. As an exception, there is a second sensor which is, however, used for diagnosis purposes. A single magnetic field sensor does not allow to detect, whether the magnetic field to be compensated is homogeneous, or inhomogeneous at the location of the object to be protected. [0014] It is a further problem when compensating electromagnetic interfering fields that it cannot be measured directly at the location at which the interfering field is to be compensated, since the object to be protected against interfering fields generally is at this location. [0015] A further problem arises, if two magnetic field compensation systems are arranged directly adjacent to one another. Then, undesired feedback effects may occur between the two systems. [0016] There are problems with the control systems in that these control systems can generally be optimized to single application. An adjustment to control tasks that are quite different, such as upon changes in the control configuration, is as a rule not possible or only in a restricted manner possible and/or is to be implemented with great difficulties. Furthermore non-linear control systems which may have a better interference field compensation than linear control systems, generally can only be implemented with high costs. When control circumstances change, the whole control circuit or the control loop would have to be newly calculated, designed and/or changed. In most cases, the direct user is not a position to do so. SUMMARY OF THE INVENTION [0017] Therefore, it is an object of the invention to provide a system for compensating electromagnetic interfering fields with which system homogeneous as well as inhomogeneous magnetic fields may be compensated. [0018] It is a further object of the invention to perform a simulation of measuring electromagnetic interfering fields at the location of the object to be protected. [0019] It is a still further object of the invention to equalize potentially arising feedback effects in the case of using two magnetic field compensation systems in immediate vicinity. [0020] In detail, a system for compensating electromagnetic interfering fields is provided, which has two real triaxial magnetic field sensors, three pairs of compensation coils, and one control unit in order to protect an object against influences of an interfering field. It is preferred to design the control unit as a control processor such as a Digital Signal Processor DSP or a field programmable gate array FPGA. [0021] The six in total output signals of the two real sensors may be combined to three output signals of a virtual sensor, by means of a freely definable kind of averaging. By choosing the averaging algorithm properly, it can be achieved that the output signals of the virtual sensor represent the amplitude of the interfering field at the location of the object to be protected. [0022] The averaging takes place by means of the control system, which receives the six output signals of the two real magnetic field sensors via six inputs. [0023] For every sensor, the output signals of the two magnetic field sensors may be represented by a three-dimensional vector. These two vectors may be combined to six-dimensional vector, i.e. a 6×1 matrix. The averaging over the output signals of the two real sensors, i.e. calculating the output signals of the virtual sensor, may be described by a matrix multiplication: [0000] V=M·S V: 6×1 matrix of the output signals of the virtual sensor; M: 6×6 matrix describing the averaging over the output signals of the real sensors; and S: 6×1 matrix of the output signals of the virtual sensor. [0027] The now available output signals (=virtual input signals of the control system) of the virtual sensor are used as an input for independent control loops operating in parallel. These control loops may be broadband, selective concerning a frequency range, or selective concerning a frequency, also. The control loops have control algorithms transforming the virtual input signals V into changed signals {circumflex over (V)}. At this, {circumflex over (V)} is a 6×1 matrix representing the in total six changed input signals of the control system. The control algorithm is described by an operator Ω. There are no limitations concerning the control algorithm being used. Accordingly, the operator Ω may not be a matrix so that nonlinear algorithms may also be used. Therefore, the transition to the modified signals {circumflex over (V)} is described by [0000] {circumflex over (V)} =Ω( V ) [0028] The matrix {circumflex over (V)} is multiplied by a 6×6 matrix L, in order to obtain control signals for the six coils, i.e. [0000] O=L·{circumflex over (V)} [0000] with: L: 6×6 matrix for calculating the control signals O from the modified signals O=L·{circumflex over (V)}. [0029] Therefore, the algorithm used by the control system may overall be described as follows: [0000] O=L·Ω ( M·S ) [0030] The more inhomogeneous the compensation field is in case of homogeneous interference, and the more homogeneous the compensation field is in case of inhomogeneous interference, the smaller is the region around the feedback sensor having a good compensation effect. [0031] If the interference field is inhomogeneous, it is not purposeful to generate a homogeneous compensation field. In this case, it is also purposeful to use a single actuator coil instead of a pair of Helmholtz coils. [0032] Only a single compensation system is used in this case, i.e. only three virtual signals are used for processing virtual sensor positions, and for generating gradient fields so that M may be a 3×6 matrix, and L may be a 6×3 matrix. Alternatively, the “not used” elements of the 6×6 matrices may also be equal to zero. [0033] In case of a Helmholtz coil arrangement, only one coil of the pair is actively actuated, and that depending on the gradient of the interfering field below the compensation region, or above the compensation region. Therefore, a rearrangement for changing the position of the single coil is not necessary besides a new parametrisation of the control loops, in case of a change of the structure of the interfering field. [0034] If two compensation systems are operated directly beside each other, this results in mutual interferences. The feedback between the two systems my be described by means of a 6×6 feedback, or crosscoupling matrix C. C represents the feedback of a control signal O i with a virtual signal V i . [0035] For avoiding interferences, the feedback system will not deliver optimal results. As a rule, an overcompensation, or an under compensation is only feasible for digital control systems, and also in this case for systems not operating in broadband. The position of the sensor would have to be fitted for all other systems. Such a change of position may it make it necessary that the sensors for the three space axes have to be positioned at different positions in space. But because one single system for all kinds of applications is not aimed for, overcompensation or undercompensation respectively is not an appropriate method. [0036] When doing so, the matrix S of the output signals of the real sensors is enlarged to a 6×1 matrix Ŝ. Therefore, it is true over all: [0000] O=L·Ω ( M ·( S−C·O )) BRIEF DESCRIPTION OF THE DRAWINGS [0037] FIG. 1 shows a schematic presentation of the system for compensating an inhomogeneous interfering field; [0038] FIG. 2 is a schematic presentation of the system for compensating electromagnetic interfering fields, together with its control system, [0039] FIG. 3 is a block diagram for calculating the control signals of the system for compensating electromagnetic interfering fields, [0040] FIG. 4 : is a schematic presentation of using the magnetic field compensation system, and [0041] FIG. 5 : is a schematic presentation of using two magnetic field compensation systems directly besides each other. DETAILED DESCRIPTION OF THE INVENTION [0042] In the following, the invention is described in more detail referring to the attached figures by means of exemplary embodiments, wherein same reference signs refer to same components. [0043] FIG. 1 schematically shows the system for compensating electromagnetic interfering fields. An object 2 to be protected against effects of the interfering field 1 is permeated by the interfering field 1 . Here, the interfering field 1 is assumed to be a gradient field. [0044] The amplitude of the interfering field 1 is measured by two real magnetic field sensors 3 , and 4 . The first real sensor 3 provides an output signal {right arrow over (S)} 1 =[x 1 (t), y 1 (t), z 1 (t)], and the second real sensor 4 provides an output signal {right arrow over (S)} 2 =[x 2 (t), y 2 (t), z 2 (t)]. These two output signals are fed in a digitised form to the control unit 7 shown in FIG. 2 . [0045] The control unit 7 has six inputs for the six signals in total, corresponding to 2×3 space axes. Furthermore, the control unit 7 has six outputs for outputting control signals for six coils 6 . [0046] The two vectors {right arrow over (S)} 1 , and {right arrow over (S)} 2 are combined to a 6-vector S=(S 1 , S 2 , S 3 , S 4 , S 5 , S 6 ). S is processed by the control unit 7 according to the algorithm schematically shown in FIG. 3 . In a first step, the six in total signals fed to the control unit 7 are converted into signals V=(V 1 , V 2 , V 3 , V 4 , V 5 , V 6 ) of a virtual sensor 5 ( FIG. 1 ). This takes place by multiplying S by a 6×6 matrix M. Therefore, it is valid: [0000] V=M·S [0047] The virtual signals V correspond to the amplitude of the interfering field at the location of the object 2 to be protected. Therefore M describes the geometry of the whole arrangement, and how the signals of the two real sensors 3 , and 4 are combined. [0048] The virtual signals V generated in such a manner are fed to independent control loops operating in parallel, and processed further. These control loops as part of the control unit 7 may be broadband, selective concerning a frequency range, or selective concerning a frequency. The control loops change the virtual signals V to modified signals {circumflex over (V)}. The transition from V to {circumflex over (V)} is described by an operator Ω. Therefore, it applies: [0000] {circumflex over (V)}=Ω ( V ) [0049] Since there are no limitations concerning the used control algorithms, the modification of the signals V is generally described by the operator Ω, which is not necessarily a matrix so that nonlinear algorithms may be used, also. [0050] For gaining control signals for the coils 6 , the modified signals {circumflex over (V)} are converted into real control signals O. O again is a 6×1 matrix, therefore containing six single signals, which are used for controlling the six coils 6 . The transition from the modified signals {circumflex over (V)} to the control signals O is therefore described by [0000] O=L·{circumflex over (V)} [0000] or over all: [0000] O=L ·Ω( M·S ) [0051] Here, L is a 6×6 matrix. The precise values of its elements depend on the nature of the interfering field to be compensated, and on the geometry of the coils 6 generating the compensation field. If, for example, a gradient field acting in x direction shall be compensated, the two coils acting in direction get differently strong signals so that the two coils generate differently high magnetic fields so that the compensation field also is a gradient field, whose direction of field intensity is inverse to the direction of the interfering field. [0052] The algorithm described up to now is used as long as one single compensation system is only used. For this case, three virtual signals are needed, only. When doing so, virtual sensor positions are calculated, and gradient fields are generated. For this purpose, it is sufficient, if M is a 3×6 matrix, and L is a 6×3 matrix. Alternatively, the “not used” elements of the 6×6 matrices may also be equal to zero. [0053] Also, two compensation system being placed directly beside each other may be operated by means of the control unit 7 . This can make sense, if two objects to be protected are directly placed beside each other, and shall, or may not be protected by a large compensation system. This implicates that, due to the two compensation systems being used, the regions to be protected have a significantly smaller volume. Therefore, no gradient fields are needed for compensation. With such an installation, generating gradient fields for compensation, however, is also not possible, because the six output signals of the control unit 7 are given to six pairs of coils, which are only able to generate a homogeneous magnetic field in each of the directions in space. The pairs of coils may be connected in series, in parallel, or depending on the impedance. These pairs of coils are each placed around the object 2 to be protected, and each of the corresponding systems is each arranged inside the cage formed by the three pairs of coils each. This configuration is shown in FIG. 4 . Three pairs of Helmholtz coils H 1 , H 2 , H 3 are arranged around the object 2 to be protected. The two real sensors 3 , 4 are inside the one cage H. [0054] Two compensation systems may also be arranged directly beside each other. This case is shown in FIG. 5 . Here, three pairs of Helmholtz coils H 1 a , H 2 a , H 3 a , or H 1 b , H 2 b , H 3 b respectively each form a cage Ha or Hb, respectively, One of the two real sensors 3 , 4 is in each of the two cages Ha, Hb. [0055] If two compensation systems are used in direct vicinity, feedback effects may arise between the two systems. This is accounted for by providing a 6×6 back coupling matrix C, which computationally eliminates the parts of the signals, which are crosstalks from an output signal O i to a virtual signal V i . Therefore, C describes the kind of feedback between the two compensation systems installed directly beside each other. [0056] According to the invention, the 6×1 matrix of the real sensor signals is expanded by the feedback part. If the 6×1 matrix of these expanded signals is denominated by Ŝ, it applies [0000] Ŝ=S−C·O [0057] The 6×1 matrix with the virtual sensor signals is calculated from the signals Ŝ expanded by the feedback part, obtained in this manner. Therefore, it applies: [0000] V=M·Ŝ [0000] finally yielding control signals according to the following relation: [0000] O=L ·Ω( M ·( S−C·O )) [0058] In the following, a standard installation of the systems shall be assumed, i.e. only one system is installed. Therefore, no feedback effects occur, which means that the matrix C is equal to the zero matrix. Furthermore, it shall be assumed that the virtual sensor signal in x direction shall be composed of the arithmetic mean of the two real sensor signals in x direction, because the gradient of the interfering field proceeds in x direction. The virtual sensor signal in y direction shall be equal to the signal in y direction of the second real sensor, because, for example, the signal in y direction of the first real sensor contains unwanted components caused by a local interferer. Due to averaging/noise suppression reasons, the virtual sensor signal in z direction shall be equal to the arithmetic mean of the two real sensor signals in z direction. Under these assumptions, the matrix M has the following form: [0000] M = ( 0 , 5 0 0 0 , 5 0 0 0 0 0 0 1 0 0 0 0 , 5 0 0 0 , 5 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 ) [0059] If the compensation coils are formed as pairs, and if a homogeneous compensation field shall be emitted in y, and in z direction, which field has a gradient in x direction, the matrix L has the following form: [0000] L = ( 0 , 5 0 0 0 0 0 0 1 0 0 0 0 0 0 1 0 0 0 1 0 0 0 0 0 0 1 0 0 0 0 0 0 1 0 0 0 ) [0060] A double installation is considered in the following example, i.e., two systems for compensating electromagnetic fields are operated directly beside each other. [0061] Since the output signals for both compensation cages are known inside the control unit 7 in this case, now also feedback parts can be taken into consideration in the control structure. This takes place, as already is described, by using a feedback, or crosscoupling matrix C. This matrix C or its elements, respectively, may experimentally be determined in a comparably easy manner, by applying a signal to an output of the first compensation system, and measuring at the second system, which components are absorbed by the sensors of the second system, and which fraction of the amplitude, in comparison with the sensor of the first system. Then, these signals parts are the elements of the feedback matrix C. When doing so, this measuring method has to be done for all coils. [0062] If, for example, the output O 5 still radiates onto the sensor input S s with 40%, the matrix element has to be C 25 =0.4.

A system for compensating electromagnetic interfering fields is provided that includes two triaxial magnetic field sensors for outputting real sensor signals; six compensation coils, which are arranged as a cage around an object to be protected, and may individually be actuated; a control unit having six inputs, and six outputs, and a digital processor receiving the sensor signals on the input side, and processing the signals to control signals for the compensation coils. The real sensor signals are converted to virtual sensor signals by a first matrix multiplication for mapping the interfering fields at the location of the object. The virtual sensor signals are made to modified signals by an operator describing the controller structure. The modified signals are converted to real control signals by a second matrix multiplication, which control signals are individually fed to the six compensation coils.

big_patent

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] The present application is the U.S. national phase of International Application No. PCT/EP2014/075901 filed Nov. 28, 2014, which claims priority of German Application No. 10 2013 224 412.6 filed Nov. 28, 2013, the entirety of which is incorporated herein by reference. FIELD OF THE INVENTION [0002] The invention relates to a method for investigating a sample, derived from a biological source, using CARS microscopy, in which method a resonance signal generated by coherent anti-Stokes Raman scattering by excitation of at least one resonance site of the sample by means of laser irradiation is sensed in image-producing fashion. BACKGROUND OF THE INVENTION [0003] “Nonlinear Raman spectroscopy” is understood to mean spectroscopic investigation methods that are based on nonlinear Raman scattering of light at solids or gases. The present invention refers to microscopic investigation methods based on coherent anti-Stokes Raman scattering (CARS). [0004] For investigation methods of this kind (also referred to as “CARS microscopy”), two lasers that emit light of different wavelengths (v P and v S , the pump and Stokes light beams), where v S should be tunable, are used to generate a CARS spectrum v CARS : v CARS =2v P −v S , I CARS ≈(I P ) 2 −I S . [0005] FIG. 2 schematically depicts a term diagram of a CARS transition. If the frequency difference v P −v S matches the frequency difference between two molecular vibration states |1> and |0> in an investigated sample, the CARS signal becomes amplified. Structures of a sample in which different molecular states of this kind occur and are also correspondingly detectable (typically, characteristic chemical bonds) are referred to hereinafter as “resonance sites.” Corresponding structures of a molecule, or molecules in general that contain them, are also referred to as “scatterers.” [0006] The pump light beam and Stokes light beam are coaxially combined for microscopy applications, and are focused together onto the same sample volume. The direction in which the anti-Stokes radiation is emitted is determined from the phase adaptation condition for the underlying four-wave mixing process, as depicted schematically in FIG. 3 . [0007] Methods and apparatuses for CARS microscopy are known, for example, from DE 102 43 449 A1 (simultaneously U.S. Pat. No. 7,092,086 B2), which describes a CARS microscope having means for generating a pump light beam and a Stokes light beam that are directable coaxially through a microscope optical system onto a sample, and having a detector for detecting corresponding detected light. [0008] Further physical principles of CARS microscopy may be gathered from current reference works (see e.g. Xie, X.S., et al., Coherent Anti-Stokes Raman Scattering Microscopy, in: J. B. Pawley (ed.), Handbook of Biological Confocal Microscopy, 3rd edition, New York, Springer, 2006). [0009] As compared with conventional or confocal Raman microscopy, in CARS microscopy it is possible in particular to achieve higher detected light yields and better suppression of obtrusive secondary effects. The detected light furthermore can be more easily separated from the illuminating light. [0010] Because, as mentioned, characteristic natural vibrations of the molecules in a sample, or of specific chemical bonds, can be used in CARS microscopy, it allows species-selective imaging that in principle dispenses with further tagging and dyes. With CARS microscopy, molecular structure information about a sample can be obtained with three-dimensional spatial resolution. [0011] CARS microscopy always relies, however, on the presence of corresponding resonance sites in the sample. If resonance sites are absent or if, for structures of interest, the frequency differences of their vibration states are not sufficiently distinguished from those of the surroundings, they cannot be detected. In addition, with known methods for CARS microscopy it is often difficult to suppress the non-resonant background. [0012] Picosecond laser pulses can be used, for example, to manipulate or decrease the non-resonant background, but they require the use of correspondingly complex lasers. Further possibilities for reducing the non-resonant background are so-called “epi-detection” and polarization-sensitive detection. Time-resolved methods are also utilized in this context. A further possibility is to control the phase of the excitation pulses. [0013] The aforesaid methods nevertheless prove to be more or less cumbersome in practice. Selective accentuation of defined structures in a sample can also be desirable in certain cases, but this is not possible in conventional methods for CARS microscopy. SUMMARY AND ADVANTAGES OF THE INVENTION [0014] The present invention aims to provide a remedy here, and its object is to furnish a correspondingly improved method for CARS microscopy. [0015] This object is achieved by a method for investigating a sample, derived from a biological source, using CARS microscopy, in which method a resonance signal generated by coherent anti-Stokes Raman scattering by excitation of at least one resonance site of the sample by means of laser irradiation is sensed in image-producing fashion, wherein the method comprises furnishing at least one resonance site by means of a bioorthogonal reaction of an intrinsic chemical structure of the sample with at least one reaction partner. [0016] Preferred embodiments are the subject matter of the description below. [0017] The present invention proceeds from a known method for CARS microscopy. A method of this kind encompasses the investigation of a sample derived from a biological source, in which method a signal generated by coherent anti-Stokes Raman scattering by excitation of resonance sites in the sample by means of laser irradiation is sensed in image-producing fashion, and in which structural properties of the chemical structures containing the resonance sites can also optionally be derived from the signal. [0018] When a “sample derived from a biological source” is referred to in the context of the present invention, this can involve a sample removed directly from a biological system, for example an animal tissue sample, a plant structure, and/or a prepared specimen derived therefrom. The present invention can also be utilized, however, in more or less highly processed samples, for example in food chemistry. The present invention is especially suitable, for example, for purity checking, for example of oils. [0019] The invention is of course particularly suitable for tagging in biological samples, for example nerve tissue, in which the intelligence of a tag can be combined with the specificity of vibrational spectroscopy. It thus becomes possible, for example, simultaneously to check lipids for tags and to process them in image-producing fashion; these could previously only be sensed separately. [0020] The structural properties of the chemical structures encompassing the resonance sites can be derived in known fashion from the signal generated by coherent anti-Stokes Raman scattering. A corresponding signal, which for example can also be obtained in the form of spectra when tunable Stokes light beams are used, contains features, for example corresponding wavelengths, bands, and/or peaks, that are specific for the respectively contained resonance sites, in particular the respective chemical bonds. These are indicated as Raman shifts or CARS shifts (which correspond to the frequency differences between the respective molecular vibration states), typically in the form of wave numbers. One skilled in the art may gather characteristic wavelengths obtained for chemical bonds from relevant reference works. [0021] The present invention is also suitable for the use of Stokes light beams of fixed wavelength. Although spectra are not acquired in this case, the signal generated by coherent anti-Stokes Raman scattering can be used in this case as well for image production. [0022] A method of this kind thus encompasses, according to the present invention, the furnishing of at least one resonance site by means of a bioorthogonal reaction of an intrinsic chemical structure of the sample with at least one further reaction partner, i.e. the introduction, by way of a bioorthogonal reaction, of a corresponding structure that is not inherently contained in the sample. [0023] The term “bioorthogonal reaction” will be further explained in detail below. The term “intrinsic chemical structure” is understood here as a chemical structure that is already contained in the sample as a result of its origin. In samples deriving from biological sources this refers, for example, to aliphatic chains having corresponding bonds in lipids, peptide bonds in proteins, and the like. Intrinsic chemical structures of this kind comprise resonance sites that can be sensed in image-producing fashion using CARS microscopy. [0024] In contrast to such intrinsic resonance sites, or the chemical structures on which they are based, resonance sites introduced according to the present invention into a sample are those that the sample does not comprise based on its natural origin. The invention thus makes it possible to equip a sample that inherently does not possess, or does not possess sufficient, resonance sites, or in which the resonance sites do not exhibit the desired localization or specificity, with corresponding resonance sites. [0025] According to the present invention provision can be made either that the at least one resonance site is at least partly part of the at least one further reaction partner, and/or that said site is generated at least partly by the bioorthogonal reaction itself. The former case corresponds fundamentally to conventional staining reactions and/or tagging reactions with fluorescent dyes. Here, as a rule, a fluorescent or color-imparting structure is furnished in a corresponding molecule, and is coupled to reactive structures of the sample. In contrast thereto, however, utilization of the method according to the present invention also makes it possible to generate resonance sites in the context of performance of the bioorthogonal reaction itself. [0026] This can be accomplished, for example, by cycloaddition of a conjugated diene to a dienophile (which can have a double or triple bond), as illustrated below: [0000] [0000] If, for example, the residue Y is used here as a coupling site, it is possible to generate, for addition and complete reaction of a suitable diene, a structure that is depicted on the right in the reaction equation above and exhibits, because of its specific properties, a well-defined CARS pattern to which a subsequent detection process can be matched. [0027] As mentioned, the method according to the present invention can also be used in particular to highlight or make visible chemical structures normally not detectable by means of CARS microscopy. [0028] The present invention makes it possible in particular, once the resonance sites have been created by means of the bioorthogonal reaction, to use small molecules that can be introduced deep into a corresponding tissue, since no steric hindrance occurs and, for example, they diffuse through a tissue. This is a substantial advantage in the context of the use of bioorthogonal reactions as compared with conventional staining techniques, for example using fluorescent dyes. This type of introduction into tissue is of particular interest because, as mentioned, three-dimensional image production is possible by means of CARS microscopy. [0029] As mentioned, the present invention is based on the use of bioorthogonal chemical reactions. “Bioorthogonal reactions” are understood in the context of the present Application as chemical reactions that can proceed in living systems without appreciably interfering with natural processes. Bioorthogonal reactions can in particular proceed with no cell-damaging effects. [0030] The term “bioorthogonality” and the chemical reactions relevant here are known to those skilled in the art (see E. M. Sletten and C. R. Bertozzi, “Bioorthogonal chemistry, or: Fishing for selectivity in a sea of functionality” [Bioorthogonale Chemie-oder: in einem Meer aus Funktionalität nach Selektivität fischen], Angew. Chem. 121 (38), 7108-7133, 2009, concurrently E. M. Sletten and C. R. Bertozzi, “Bioorthogonal Chemistry: Fishing for Selectivity in a Sea of Functionality,” Angew. Chem. Int. Ed. Engl. 48 (38), 6974-6998, 2009). An overview is also provided by K. V. Reyna and Q. Lin, “Bioorthogonal Chemistry: Recent Progress and Future Directions,” Chem. Commun. (Camb.) 46(10), 1589-1600, 2010. [0031] Typical bioorthogonal reactions encompass, for example, 1,3-dipolar cycloaddition between azides and cyclooctynes (so-called “copper-free click chemistry,” see J. M. Baskin et al., “Copper-Free Click Chemistry for Dynamic In Vivo Imaging,” Proc. Natl. Acad. Sci. USA 104 (43), 16793-16797, 2007). Other typical reactions are the reaction between nitrones and the aforesaid cyclooctynes, oxime/hydrate formation from aldehydes and ketones, tetrazine reactions, isonitrile-based click reactions, and quadricyclane formation. [0032] A Diels-Alder reaction and/or a Staudinger ligation are considered particularly advantageous for use in the bioorthogonal reaction according to the present invention. Staudinger ligation is a highly chemoselective method for producing bioconjugates. The respective reaction partners are bioorthogonal to almost all functional groups present in biological systems, and already react in an aqueous environment at room temperature. This allows Staudinger ligation to be used even in the complex surroundings of a living cell. Reference is made, regarding details, to the relevant technical literature (see e.g. S. Sander et al., “Staudinger Ligation as a Method for Bioconjugation,” Angew. Chem. Int. Ed. Engl. 50 (38), 8806-8827, 2011). [0033] The use of bioorthogonal reactions typically encompasses two steps. Firstly a cellular substrate, i.e. in this case the sample to be investigated, is equipped with a bioorthogonal functional group that is introduced into the sample and is also referred to as a “chemical reporter.” Substrates that are used include, for example, metabolites, enzyme inhibitors, etc., and in the context of the present invention all compounds or tissues that are to be tagged and for which improved visualization in CARS microscopy is desired. The bioorthogonal functional group, also referred to as a chemical reporter, must not substantially modify the structure of the sample, so as not to negatively affect bioactivity. In a second step a tagging substance, having a complementary functional group that reacts with the chemical reporter, is introduced. [0034] The use of bioorthogonal reactions in combination with CARS microscopy makes possible dedicated detection of target sites in any samples, for example in cells, without negatively affecting biochemical processes that may continue to occur. Subsequently thereto, the tagging reaction causes the actual synthesis or introduction of the “active” substance for CARS image production. [0035] This method allows the CARS-active scattering cross section of the respective target to be increased, or to be generated in the first place by suitable synthesis reactions. A corresponding method combines, by way of chemical image production, the advantage of known multi-photon techniques with a corresponding selective reaction. Especially as compared with the conventional use of fluorescent dyes as image-producing elements (e.g. for single-photon methods), target sites located deeper in the tissue can be utilized for image production thanks to the advantageous steric properties of the compounds used in the bioorthogonal reactions. [0036] A further advantage that can be obtained by way of the features proposed according to the present invention is, as mentioned, a reproducible counter-staining of the non-resonant background in the context of CARS microscopy. [0037] As mentioned, CARS methods generally take into account a non-resonant background that can conventionally also be used as a “counter-stain.” This has the disadvantage, however, that the background is statistical. With the features proposed according to the present invention, on the other hand, a defined background can be introduced by way of a corresponding actively performed “counter-stain,” so that specific molecules can be targeted and the resulting image can be correlated with the background that has been generated. This enables an improvement in the reproducibility of corresponding CARS methods, as well as improved quantitative conclusions. [0038] As is generally known, conventional Raman methods are not overly sensitive and require strong Raman scatterers. CARS microscopy is substantially more sensitive, although it cannot be used like Raman spectroscopy in highly specific complex substance mixtures. In some circumstances this lower specificity is not sufficient for the task on which the investigative method is based. The invention, on the other hand, allows a corresponding increase in specificity and additionally an increase in scattering cross section when the latter is necessary. [0039] Particularly advantageous examples of bioorthogonal reactions in the context of the present invention encompass at least one reaction step in the form of a modified Huisgen cycloaddition, a nitrone dipolar cycloaddition, a norbornene cycloaddition, a (4+1) cycloaddition, and/or an oxanorbornadiene cycloaddition. [0040] The aforementioned copper-free click reactions are particularly suitable for use in the context of the present invention, for example utilizing cyclooctynes. The cyclooctynes are, for example, coupled to an azide group that can in turn be introduced into a corresponding sample as a first reaction partner. Azide groups are bioorthogonal in particular because they are small, and can thus penetrate easily into the corresponding tissue and not produce any steric changes. Azides do not occur in natural samples, so that no competing secondary biological reactions exist (see M. F. Debets et al., “Azide: a unique dipole for metal-free bioorthogonal ligations,” Chembiochem. 11(9), 1168-84, 2010). Cyclooctynes are larger, but they have sufficient stability and orthogonality that they too are suitable for in vivo tagging. [0041] A tetrazine reaction, a tetrazole reaction, and/or a quadricyclane reaction can also, in particular, be used in the context of the present invention as at least one reaction step of the bioorthogonal reaction. Such reactions are also known in principle. [0042] As already explained repeatedly, the at least one intrinsic structure of the sample can firstly be coupled to a first reaction partner, and the reaction partner coupled to the intrinsic structure of the sample can then be coupled to a further reaction partner. Any reaction partner can encompass the resonance site, or the latter can be formed only by a reaction among any two or more reaction partners. [0043] A method in which a structure of the sample which does not intrinsically have a resonance site is equipped with a resonance site by means of the bioorthogonal reaction is regarded as particularly advantageous. As explained, this relates in particular to the inherently non-resonant background, which in conventional methods yields statistical signals that are nevertheless not reproducible. The invention, conversely, makes it possible to tag the non-resonant background with corresponding resonance sites and thus to generate a stable, reproducible background signal. The latter is advantageously generated by selecting suitable compounds in such a way that it stands out in contrasting fashion from the structures that are actually of interest, for example exhibits peaks at distinctly different wavelengths. [0044] A corresponding method can encompass furnishing resonance sites for the structures of the non-resonant background of the sample, and correlating a signal component of the resonance signal attributable to those resonance sites with a signal component attributable to intrinsic resonance sites of the sample. [0045] It is understood that the features recited above and those yet to be explained below are usable not only in the respective combination indicated, but also in other combinations or in isolation, without departing from the scope of the present invention. [0046] The invention is schematically depicted in the drawings on the basis of an exemplifying embodiment, and will be described in detail below with reference to the drawings. DESCRIPTION OF THE FIGURES [0047] FIG. 1 schematically illustrates a CARS microscope that can be used in a method according to an embodiment of the invention. [0048] FIG. 2 shows a term diagram of a CARS transition that can be the basis of an embodiment of the invention. [0049] FIG. 3 illustrates a four-wave mixing process that can be the basis of an embodiment of the invention. [0050] FIG. 4 illustrates a method according to an embodiment of the invention in accordance with a schematic diagram. [0051] FIG. 5 illustrates a method according to an embodiment of the invention in accordance with a schematic diagram. [0052] FIG. 6 illustrates a method according to an embodiment of the invention in accordance with a schematic flow chart. [0053] In the Figures, elements that correspond to one another are labeled with identical reference characters and are not repeatedly explained. DETAILED DESCRIPTION OF THE INVENTION [0054] FIG. 1 shows a microscope, embodied as confocal scanning microscope 100 , that contains a laser 101 for generating a light beam 102 of a first wavelength of, for example, 800 nm. Laser 101 can be embodied as a mode-coupled titanium-sapphire laser 103 . Light beam 102 is focused with an incoupling optic 104 into the end of a, for example, microstructured optical element 105 for wavelength modification, which element can be embodied as a light-guiding fiber made of photonic band gap material 106 . [0055] An outcoupling optic 108 is provided, for example, in order to collimate the wavelength-broadened light beam 107 that emerges from the light-guiding fiber made of photonic band gap material 106 . The spectrum of the correspondingly wavelength-modified light beam is as a result, for example, almost continuous over the wavelength region from 300 nm to 1600 nm, the light power level being largely constant over the entire spectrum. [0056] Wavelength-broadened light beam 107 passes through a suppression means 108 , for example a dielectric filter 109 , that, in wavelength-broadened light beam 107 , reduces the power level of the light component in the region of the first wavelength to the level of the other wavelengths of wavelength-broadened light beam 107 . Wavelength-modified light beam 107 is then focused, for example with an optic 110 , onto an illumination pinhole 111 , and then arrives at a selection means 112 that is embodied as an acousto-optical component 113 and functions as a main beam splitter. A pump light beam 114 and a Stokes light beam 115 , each having a wavelength defined by a user, can be selected with selection means 112 . [0057] From selection means 112 , pump light beam 114 and Stokes light beam 115 , which proceed coaxially, travel to a scanning mirror 116 that guides them through a scanning optic 117 , a tube optic 118 , and an objective 119 and over a sample 1 . Detected light 120 emerging from sample 1 , which light is depicted in the drawing with dashed lines, travels (when, for example, descanned detection is provided) back through objective 119 , tube optic 118 , and scanning optic 117 to scanning mirror 116 and then to selection means 112 , passes through the latter, and after traversing a detection pinhole 121 is detected with a detector 122 that is embodied as a multi-band detector. When, for example, non-descanned detection is likewise provided, two further detectors 123 , 124 can be provided on the condenser side. Detected light 125 emerging in a straight-ahead direction from the sample is collimated by a condenser 126 and distributed by a dichroic beam splitter 127 , as a function of wavelength, to further detectors 123 , 124 . Filters 128 , 129 are provided in front of the detectors in order to suppress those components of the detected light which have the wavelengths of pump light beam 114 or of Stokes light beam 115 , or of other light. [0058] FIGS. 2 and 3 have already been referred to in the introductory section. [0059] FIG. 4 shows, in the respective partial figures A and B, a sample 1 derived from a biological source. Sample 1 can be, for example, a cell to be tagged and/or a surface of a microscopic section and/or a correspondingly prepared tissue sample. [0060] In the example depicted, sample 1 comprises an intrinsic chemical structure, labeled 2 , that is capable of coupling with a reaction partner, here labeled 3 . In the example depicted, reaction partner 3 encompasses a coupling site 4 and a resonance site 5 that, upon excitation by means of laser irradiation, can produce a resonance signal as a result of coherent anti-Stokes Raman scattering. [0061] Figure detail A of FIG. 4 shows a non-coupled state between intrinsic chemical structure 2 of sample 1 and reaction partner 3 . Partial figure B, on the other hand, illustrates a coupled state, the result of which is that resonance site 5 of reaction partner 3 can now be used as part of sample 1 for detection. [0062] Whereas FIG. 4 and its parts A and B show a single-stage reaction, FIG. 5 illustrates a two-stage reaction. In this, intrinsic chemical structure 2 is firstly coupled to a coupler molecule 6 that comprises a first functional group 7 for coupling to intrinsic chemical structure 2 of sample 1 , and a second functional group 8 for coupling to reaction partner 3 that carries resonance site 5 . Intrinsic chemical structure 2 of sample 1 couples here to first functional group 7 of coupler molecule 6 ; reaction partner 3 couples with its coupling site 4 to second functional group 8 of coupler molecule 6 . Coupling sites 4 and resonance sites 5 that are in part drawn differently in FIGS. 4 and 5 serve only for illustration. According to FIG. 5 as well, resonance site 5 becomes part of sample 1 and can correspondingly be detected. Unlike in FIG. 4 , however, partial figure A here shows a coupled state, and partial figure B an uncoupled state. [0063] In FIG. 6 a method according to an embodiment of an invention is depicted in the form of a schematic flow chart and is labeled 10 in its entirety. The method begins in a method step 11 with the furnishing of a sample 1 . In a method step 12 a bioorthogonal reaction of an intrinsic chemical structure of the sample with at least one further reaction partner is carried out. In a step 13 the sample, having the resonance site that has been furnished by means of the bioorthogonal reaction in step 12 , is introduced into a suitable investigation system, for example a CARS microscope according to FIG. 1 . In step 14 an investigation of the sample is performed in the investigation system. A correspondingly obtained signal is sensed in a step 15 and used, for example, to derive at least one structural property of a chemical structure containing the at least one resonance site.

A method for investigating a sample ( 1 ), derived from a biological source, using CARS microscopy is proposed, in which method a resonance signal generated by coherent anti-Stokes Raman scattering by excitation of at least one resonance site ( 5 ) of the sample ( 1 ) by means of laser irradiation is sensed in image-producing fashion. The method according to the present invention encompasses furnishing at least one resonance site ( 5 ) by means of a bioorthogonal reaction of an intrinsic chemical structure ( 2 ) of the sample ( 1 ) with at least one reaction partner ( 3, 6 ).

big_patent

CROSS-REFERENCED TO RELATED APPLICATION This application claims the benefit of U.S. provisional application 61/057,554 filed May 30, 2008 and hereby incorporated by reference. BACKGROUND OF THE INVENTION Medical equipment for radiation therapy treats tumorous tissue with high-energy radiation. The amount of radiation and its placement must be accurately controlled to ensure both that the tumor receives sufficient radiation to be destroyed, and that the damage to the surrounding and adjacent non-tumorous tissue is minimized. In external source radiation therapy, a radiation source external to the patient treats internal tumors. The external source is normally collimated to direct a beam only to the tumorous site. The source of high-energy radiation may be from linear accelerators as x-rays, or electrons, protons, neutrons or any other form, in the range of 2-300 MeV, or gamma rays from highly focused radioisotopes such as a Co60 source having an energy of 1.25 MeV. Typically, the tumor will be treated from several different angles with the intensity and shape of the beam adjusted appropriately. The purpose of using multiple beams, which converge on the site of the tumor, is to reduce the dose to areas of surrounding non-tumorous tissue. The angles at which the tumor is irradiated are selected to avoid angles which would result in irradiation of particularly sensitive structures near the tumor site. The angles and intensities of the beams for a particular tumor form a treatment plan for that tumor. More-advanced, highly accurate modalities of radiation delivery have been developed to further customize a treatment plan to conform dose to a target region while limiting dose outside that target. Such modalities modulate individual “beamlets” of radiation within each beam so that all beamlet from all beams, in sum, create an optimal plan. Beamlet modulation may be achieved in many ways, including: temporal motion of multi-leaf collimators during delivery, rotational beams with moving collimators, solid physical modulator that optimizes the beam through a precision milled device, and non-coplanar robotic arms delivering many small, distinct beams from many angles. In order to take advantage of the improved accuracy in dose placement offered by such optimized radiation planning and delivery systems, the radiation treatment plan may be based on a digitized virtual model of the patient's anatomy, which is built using volumetric medical imaging. The most common in volumetric medical imaging modalities are computed tomography (“CT”) and magnetic resonance imaging (“MRI”) As is known in the art, a CT image is produced by a mathematical reconstruction of many projection images obtained at different angles about the patient to provide an image of “slices” or planes throughout the patient. Using the stack of CT images, the radiologist views the tumorous area and determines the beam angles and intensities (identified with respect to the tumor image) which will be used to treat the tumor. Different regions may be defined within each slice plane of a series of CT images in a process known as “segmentation.” For example, regions to receive high-dose may be defined on each CT image by creating segmentation of “target areas” in that image, whereas regions that should be spared radiation because of radiation sensitivity may also be segmented in that 2D image to help guide the treatment planner on where to avoid high doses. Additional areas of segmentation may also be defined with different dose levels. This process is repeated for multiples adjacent CT images to provide a three-dimensional segmentation. The segmentation may be done manually by clinicians (i.e. a trained dosimetrist may segment the critical sparing organs, while a physician may define the target regions) or by using various automatic segmentation programs such as those commercially available from Varian Medical Systems, Inc. of California, USA under the Eclipse “Smart Segmentation” trade name, from Royal Philips Electronics of the Netherlands in their Pinnacle system under the trade designation “Model-based Segmentation,” and from CMS, Inc of Missouri, USA under the trade name “Atlas-based Autosegmentation.” The results of the segmentation are stored in segmentation files, currently under a DICOM standard as DICOM-RT Structure Set files. These files contain point data defining the periphery of a volume in multiple parallel planes or slices. SUMMARY OF THE INVENTION The present invention provides a system for assessing segmentations from various sources. For example, a “gold standard” segmentation approved by a clinician (a physician or senior dosimetrist) may be compared against segmentation provided by clinicians in training or different software systems, and/or the segmentation from different software systems may be compared against each other. In a preferred embodiment, the comparison process accepts as inputs, segmentations, or “regions of interest” (ROIs) recorded in electronic files, for example, using the DICOM-RT standard. The segmentations are converted to volume models and the volume models are compared to identify volume elements that are missing or extra between the first and second segmentation. The missing and extra volume elements may be measured and optionally weighted according to their distance from the reference (i.e. “correct”) volume elements to produce an output indicating the quality of the one segmentation with respect to the other. The invention may also be used for periodic quality assurance of autosegmentation routines or evaluation of those routines when they are updated or used with new imaging technology. Specifically, then the present invention provides an apparatus for automatically assessing radiation therapy segmentations. The apparatus uses an electronic computer executing a stored program to receive a first and second electronic file each providing data points describing different three-dimensional surfaces circumscribing a structure in a human patient intended for radiation therapy. The files are used to generate a first and second volume model, per ROI, defined by the first and second electronic file respectively. These volume models are compared to identify common volume elements in common to both of the first and second volume models, missing volume elements of the first volume model that are not in the second volume model, and extra volume elements of the second volume model that are not in the first volume model. A measure of a conformance between the three-dimensional surfaces circumscribing the structure defined by the first and second electronic files is then output based on a metric method measuring numbers of missing volume elements and extra volume elements. It is therefore one feature of at least one embodiment of the invention to provide a tool for comparing the quality of segmentations from different sources and, thus, that is generally useful for training, evaluation and product evaluation purposes. The first and second volume models may be constructed by identifying a set of voxels within the three-dimensional surfaces, and the step of comparing the first and second volume models may evaluate each voxel of a union of the set of voxels of the three-dimensional surfaces on a voxel by voxel basis to identify and measure the missing and extra volume elements. It is therefore one feature of at least one embodiment of the invention to provide a simple method of comparing segmentation volumes through the use of digitized volume elements readily processed by digital computer hardware. The electronic computer may include a graphic display screen and the stored program may display a cross-sectional image through the first and second volume models along a user-defined cross-sectional plane separately identifying the common volume elements, missing volume elements, and extra volume elements by different colors. It is therefore one feature of at least one embodiment of the invention to provide an output that can assist a user in improving their segmentation skills or autosegmentation programs by identifying not simply quality of the segmentation but the regions of error. The common volume element elements may be colored green, the missing volume element elements blue and the extra volume element elements red. It is therefore one feature of at least one embodiment of the invention to provide an intuitive display form that can be rapidly assessed by an individual with minimal training. The stored program may further receive a third electronic file providing a cross-sectional image of patient tissue at the user defined cross-sectional plane, and the cross-sectional images through the first and second volume models may be displayed superimposed on the cross-sectional image of patient tissue obtained from a third electronic file. It is therefore one feature of at least one embodiment of the invention to permit the review of segmentation region differences against the underlying data used for the segmentation, providing additional instructive detail for an individual improving his or her skills or for an individual assessing an autosegmentation program. The metric method may provide a summation of a first function based on the missing volume elements and a second function based on the extra volume elements so that the metric method increases monotonically with increased missing volume elements and extra volume elements. It is therefore one feature of at least one embodiment of the invention to provide a system that is sensitive both to overinclusive segmentation and underinclusive segmentation, both of which can have significant clinical effects. The step of comparing the first and second volume models may also identify a distance measure for each missing volume element from a closest common volume element and a distance measure for each extra volume element from a closest common volume element wherein the distance measure provides a variable for weighting of the volume of each missing volume element and each extra volume element in the metric method. It is therefore one feature of at least one embodiment of the invention to discount the influence of errors close to the desired segmentation surface but to emphasize errors far from the segmentation surface to approximate the clinical significance of these elements given the limits of resolution of typical radiation therapy systems. The electronic computer may include a user input device for accepting a representation of the metric method to allow a user to set the metric method. It is therefore one feature of at least one embodiment of the invention to permit wholly customized metric methods as knowledge in this area in advances. The metric method may be a combination of: a constant value, a linear function of a number of error volume elements with distance, and an exponential function of the number of error volume elements with distance; wherein the error volume elements are missing volume elements and/or extra volume elements. It is therefore one feature of at least one embodiment of the invention to provide a simple method of constructing complex functional metric functions by specifying simple parameters associated with constant, linear, and exponential functions. The electronic computer may display a histogram showing cumulative missing volume elements as a fiuction of distance ranges and cumulative extra volume elements as the function of distance ranges. It is therefore one feature of at least one embodiment of the invention to provide a display that reveals possible systematic distance errors and different distance related error trends. The first and second electronic files may provide text strings identifying the structure and the stored program may select the metric method from a set of metric methods according to a table mapping the text strings identifying the structure of the first and second electronic files to one of the set of metric methods to be used as the metric method. It is therefore one feature of at least one embodiment of the invention for different metric methods to be applied to different structures automatically or semi-automatically based on common structure descriptors. The stored program may further execute to display a function of the metric method as a graph together with function parameters entered by the user and to change the graph as the function parameters are changed by the user. It is therefore one feature of at least one embodiment of the invention to provide a graphic representation of the metric method to assist in development of custom metric methods. These particular features and advantages may apply to only some embodiments falling within the claims and thus do not define the scope of the invention. BRIEF DESCRIPTION OF THE FIGURES FIG. 1 is a simplified representation of the electronic files used to record segmentations for patient structures and their use in radiation therapy; FIG. 2 is a block diagram of a computer suitable for practice of the present invention; FIG. 3 is a flow chart showing processing of the files of FIG. 1 with respect to the present invention; FIG. 4 is a first interface screen produced by the present invention and used for identifying electronic files for the evaluation process of the present invention; FIG. 5 is figure similar to that of FIG. 4 showing a display of segmentations for two files for a given structure at a cross-sectional plane selected by the user; FIG. 6 is a figure similar to FIGS. 4 and 5 showing a table permitting the automatic matching of metric methods to particular structures by structure name in the electronic files; FIG. 7 is a simplified representation of two segmentation volumes in cross-section per the display of FIG. 5 showing different measurements made by the present invention; FIG. 8 is an interface screen used for defining a metric method such as is used in the table of FIG. 6 ; FIG. 9 is a display of a graphical representation of the conformance of the segmentations per a metric method; and FIG. 10 is a quantitative display of the result of the comparison of the segmentations per a metric method. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG. 1 , a set of electronic segmentation files 10 may be prepared as indicated using a segmentation process 11 by either a clinician 15 or through the use of an autosegmentation program 14 as is understood in the art and described generally above in the Background Of The Invention. The segmentation files 10 typically provide image-like data depicting a segmentation 12 in the form of a set of points on one or more image planes defining a periphery of a structure 22 within the patient 23 . The preparation of the segmentation files 10 is normally conducted by viewing a set of sequential slice images (not shown) obtained by a conventional medical imaging device such as a CT or MRI scanner. In the case where the segmentation files 10 are prepared by the clinician 15 , the points of the segmentation 12 may be traced on the slice images. In the case where the segmentation files 10 are prepared by an autosegmentation program 14 , the program analyzes variations in the data of the images against a knowledge of anatomy with general guidance by a clinician 15 . As is understood in the art, the segmentation files 10 may be used to guide a radiation therapy machine 16 having a fixed, movable radiation and/or rotational source 18 that may project a radiation beam 20 at a variety of angles about a patient 23 toward an internal structure 22 . The alignment and intensity of the radiation beams 20 are guided by the segmentation files 10 and dose values associated therewith. Typically, a segmentation file 10 will include information identifying the patient and naming the structure 22 , information describing the units and orientation of the segmentation 12 , and may include other information for operating the radiation therapy machine 16 . Referring now to FIGS. 1 and 2 , the present invention may provide a program executable on a standard electronic computer 24 that may receive a different segmentation file 10 related to identical structure 22 in order to evaluate the quality of the segmentations of the segmentation files 10 or to evaluate the segmentation process. The electronic computer 24 may receive the segmentation files 10 , for example, over a network connection 26 from a file server or by means of any suitable storage media such as optical discs, flash drives, and the like, through a media reader (not shown) and would have the ability to provide a printed output through a printer (not shown). The electronic computer 24 may provide an internal bus 28 connecting: a network interface 30 communicating with the network connection 26 , a memory 32 , a processor 36 , a graphics interface 38 , and a user input interface 40 , all of types known in the art. The graphics interface 38 may connect to a graphics display screen 42 allowing the computer 24 display images and text. The user input interface 40 may connect to a keyboard 44 or cursor control device 46 or the like or any other device allowing input by the user. The processor 36 executes a stored program 48 of the present invention using an operating system 50 . Referring now to FIG. 3 , the stored program 48 of the present invention provides, at a first step indicated by process block 51 , an inputting of two or more electronic segmentation files 10 providing for segmentations 12 for the same structure 22 (as shown in FIG. 1 ) but from a different source. For example, the first electronic segmentation file 10 may be one prepared by an experienced clinician to provide a “gold standard” segmentation for the structure 22 . The second segmentation file 10 ′ may be a segmentation by a less experienced clinician who is being trained or by an autosegmentation program being evaluated. Referring now also to FIG. 4 , the program 48 may produce a first interface screen 52 on the graphics display screen 42 allowing identification and loading of the segmentation files 10 per process block 51 of FIG. 3 . A first segmentation file 10 may be identified by clicking on a display button 53 to invoke a standard file browser window (not shown) allowing identification of a particular segmentation file 10 that will be used as a “standard” file in the comparison process and denoted as file 1 . A data box 56 in the same row as the button 53 provides information about the segmentation file 10 identified in this process as extracted from the segmentation file 10 to assist in its proper verification. Similarly, a second button 54 may be pressed to identify a second segmentation file 10 ′ that will be used as the “compared” file and denoted as file 2 . Again the second column in this row provides a data box 56 providing details about the segmentation files 10 ′ to assist in its identification. A third column in common with the first and second rows holding buttons 53 and 54 provides a text box 58 identifying structures 22 of the first and second segmentation files 10 , 10 ′ by text strings embedded in the segmentation files 10 , 10 ′ and showing those structures 22 (for example, “SPINAL CORD”) that are in common between the first and second segmentation files 10 , 10 ′. Only segmentations 12 for structures 22 matching in these two segmentation files 10 , 10 ′ will be compared. The identification of common structures may be by means of the structure names embedded in the segmentation files 10 , 10 ′ and matched using well known string matching algorithms per process block 67 of FIG. 3 . A third button 60 operates in a manner analogous to that described above with respect to buttons 53 and 54 to load an image file providing a medical image of the structures 22 being segmented in the segmentation files 10 , 10 ′ that is typically the same image(s) used for the segmentation process 11 . Any spatial offset among the segmentations 12 of the first and second segmentation files 10 , 10 ′ can be corrected by origin reset entry boxes 59 to ensure that the segmentations 12 are all aligned with the common origin. Referring now to FIG. 5 , the previous interface screen 52 may be invoked by a menu button 62 visible at a start up screen (not shown) and for most subsequent screens. Referring still to FIG. 5 , pressing a second menu button 64 provides a new interface screen 61 allowing particular matching structures displayed in text box 58 to be selected per selection box 66 using checkboxes. The outlines defining the segmentations 12 of the segmentation files 10 , 10 ′ for the selected structures 22 are then displayed in spatial alignment on cross-sectional display 68 in an outline color selected at the selection box 66 (specified in the structure RT file). In the cross-sectional display 68 , the cross-sectional plane of the display is selected by the user using a plane identification window 70 showing an elevational view of the patient 23 and a cut line 73 being an edgewise view of the cross-sectional plane and by “dragging” arrow 72 up or down using the cursor control device 46 of FIG. 2 or by changing a slice number 74 on a display. At the selected cross-sectional plane, the corresponding segmentation 12 of the first segmentation file 10 is displayed in a solid line and the segmentation 12 ′ of the second segmentation file 10 ′ is displayed in a dotted line superimposed thereupon. In one embodiment, the line types can be selected by “scrolling” with a mouse wheel or similar device. The cross-sectional display 68 thus shows roughly the conformance between the segmentations 12 and 12 ′ of the standard and target segmentations. Referring to FIGS. 3 and 6 , at subsequent process block 69 , a measurement metric for the comparison of the segmentations 12 and 12 ′ is now identified. This identification of a measurement metric is performed using interface screen 77 invoked by pressing a measurement metric button 78 . The interface screen 77 displays an assignment of measurement metrics to particular structures 22 of the segmentations 12 and 12 ′ in an assignment window 71 which links, in rows, one or more text names of structures in a first column 75 to titles of particular measurement metrics in a second row 76 . Thus, for example, the structure 22 of the prostate represented by either of the text strings “Prostate” or “PROST” may be matched to a measurement metric entitled “linear — 3 mm”. This assignment window 71 represents an underlying table structure that may be initialized and modified by the user. The interface screen 77 provides a method of checking this assignment and of changing the particular measurement metric associated with a structure through drop-down menus listing other measurement metrics. Structures 22 that are not found in the table underlying assignment window 71 may use a default formula entered in text block 79 . A particular measurement metric may be preestablished formulas as will be described or may be defined by the user. Referring now to FIG. 7 , in either case, the measurement metrics receive data indicating how well the compared segmentation 12 ′ matches the standard segmentation 12 in terms of their volumetric overlap. Generally, the data for the measurement metric is prepared by first identifying “missing” volume elements 80 in the segmentation 12 ′ that are not in the standard segmentation 12 . Next, “extra” volume elements 82 that are found in the standard segmentation 12 but not in the compared segmentation 12 are identified. Finally, “common” volume elements 84 that are found in both the standard and the compared segmentations 12 and 12 ′ are identified. In addition, a scalar distance 86 between each given volume element 88 in either of the missing volume elements 80 or extra volume elements 82 (only the latter shown) and the closest volume element 88 ′ in the common volume elements 84 is determined. Alternatively, this scalar distance 86 may be a center of gravity or similar measurement of the region of the missing volume elements 80 or extra volume elements 82 . Each measurement metric may provide a different treatment of one or more of these volume elements and scalar distances. Referring now to FIG. 8 , clicking menu button 90 invokes an interface screen 92 that allows custom entry of metric methods through formula parameter table 94 and a formula graph 96 . The formula parameter table 94 allows the user to develop their own formulas and to name them with a text string per the first column of the formula parameter table 94 entitled: “metric methods”. This same title will be used in table of assignment window 71 of FIG. 6 . The row following the name of the metric method permits the user to enter a set of parameters for the desired metric method. The particular parameters include: “mm Forgive (+)”, mm UpperCutoff(+), “A(+)”, “B(+)”, “C(+)”, and “D(+)” being associated with extra volume elements 82 and parameters “mm Forgive (−)”, mm UpperCutoff(−), “A(−)”, “B(−)”, “C(−)”, and “D(−)” being associated with missing volume elements 80 . Generally the “mm Forgive” parameters describe a scalar distance 86 equal to or below which volume elements 80 or 82 are not counted and mm UpperCutoff(+) represents a limit beyond which volume elements 80 or 82 incur no further penalty. This allows small errors in conformance of segmentation 12 and segmentation 12 ′ to be disregarded and large errors to be discounted. The parameters A-D provide for weightings for the counting of volume elements 80 and 82 as functions of the distance 86 . Parameter A provides a constant weighting (independent of distance) equal to the value of A according to the formula of W1=A. Parameter B provide a linear weighting as a function of distance (d) according to the formula: W 2= B*d. Parameters C and D provide an exponential weighting of the volume elements as a function of distance according to the formula: W3=Ce dD . The metric method produces an evaluation number E that is equal to: E = 100 * [ P ⁢ ⁢ V - V ⁢ ⁢ P P ⁢ ⁢ V ] where PV is the number of common voxels and VP is the voxel penalty computed as follows: V ⁢ ⁢ P = ∑ m ⁢ Penalty ⁡ ( v m ) + ∑ e ⁢ Penalty ⁡ ( v e ) where v m are missing voxels and v e are extra voxels and the Penalty function for these voxels is a function of the distance 86 of each voxel as follows: Penalty ⁡ ( v i ) = [ d ⁡ ( v i ) < Forgive 0 Forgive ≤ d ⁢ ( v i ) ≤ UpperCutoff A + ( B * d ⁡ ( v i ) ) + C ⁢ ⁢ ⅇ d ⁡ ( v i ) * D d ⁡ ( v i ) > UpperCutoff A + ( B * UpperCutoff ) + C ⁢ ⁢ ⅇ UpperCutff * D ] where the values of A, B, C and D are A(+), B(+), C(+), and D(+) respectively for the extra volume elements 82 and A(−), B(−), C(−), and D(−) respectively for the missing volume elements 80 . This parameterization allows for the fast generation of complex metric methods on a custom basis. Below the table 94 , the graph 96 plots the metric method as plot line 98 for the extra volume elements 82 (the first summation in the above formula) and plot line 100 for the missing volume elements 80 (the second summation in the above formula). Alternatively, the user may enter any mathematical formula combining the data described above relating to the scalar distance and number of missing, extra, and common voxels. Referring again to FIG. 3 , once the proper metric methods have been developed and associated with a particular structure 22 , as indicated by process block 101 , the electronic segmentation files 10 and 10 ′ which describe segmentations 12 and 12 ′ are “voxelized”. This process takes the segmentations 12 and 12 ′, which are constructed of a set of points 102 together forming closed curve for each of multiple cross-sectional planes, and creates a voxel model 104 conforming generally to the bounded volume. In the preferred embodiment, each voxel is cubic with 1 mm or smaller edge dimensions. This process of converting these segmentations 12 and 12 ′ to a voxel model may be conducted by a suitable technique for determining points inside of a complex and potentially bifurcated surface, the likes of which are known in the field of image processing and image generation. One method would be to discretize 3D space into an orthogonal voxel grid, then analyze each voxel to see if the center of the voxel lies inside the areas encompassed by the closed loop 2D ROI contours specified in the structure set, allowing multiple close loop areas for bifurcated ROIs (i.e. when more than one closed loop is assigned to a single ROI for one slice). Voxels that fall in between slices could be analyzed based on either: a) the 2D contours of the nearest slice, or b) interpolated 2D contours based on the surrounding planes. Upon completion of this process of building voxel models, per process block 101 at process block 108 , the voxel models are adjusted for any origin offsets previously entered by the user (per interface screen 52 ) so that the voxel models are aligned in a common reference space with respect to the structure 22 they define. Once this process is complete, then at process block 111 , a comparison of the voxel models for the segmentations 12 and 12 ′ is conducted characterizing each of the voxels 106 as common, missing, or extra as described above, and determining the scalar distances also described above as indicated by process block 140 of FIG. 3 . Referring now to FIG. 9 , a next interface screen 110 may be invoked by pressing the menu button 112 , which provides an analysis window 114 for displaying the segmentations in a manner similar to that described with respect to FIG. 5 but shaded inside the outlines to separately indicate the volume elements that are common, missing, or extra. In the preferred embodiment, common volumes 116 are shaded green, the missing volumes 118 are shaded blue, and the extra volumes 120 are shaded red. The images of the shaded volumes may be superimposed over an image of the actual structure 122 as was acquired with respect to the interface screen 52 described in FIG. 4 . This evaluation of the common, missing, and extra volume elements may be performed simply by evaluating in turn each of the voxels in a set comprising the union of all voxels in the first and second voxel model to identify if they have a counterpart in the other model. Alternatively, it will be understood that this process can be conducted without a voxelization, for example, by approximating the volumes using a set of thin rectangular areas in each cross-sectional plane and computing the intersection of these areas using graphical algebraic techniques. Referring now to FIG. 10 , pressing menu button 130 invokes an interface screen 132 providing for a quantitative evaluation of the comparison of the two segmentations 12 and 12 ′. This evaluation may be performed simultaneously on multiple structures as output through a table 134 which may indicate the following quantitative values: (1) primary volume (volume in cubic millimeters or centimeters of the standard segmentation 12 ); (2) secondary volume (volume in cubic millimeters or centimeters of the compared segmentation 12 ); (3) missing volume (volume in cubic millimeters or centimeters of the missing volume elements 80 ); (4) extra volume (volume in cubic millimeters or centimeters of the extra volume elements 82 ); and (5) metric method/metric score (the name of the metric method and the resulting evaluation.) A histogram table 136 tallies the voxels of the missing and extra volumes according to a distance measurement bin. In this example, the voxels of the missing volume elements are plotted extending to the left of the zero point and the voxels of the extra volume elements are plotted to the right of the zero point. A report may be printed by pressing menu button 138 . The present invention may be used in the training of clinicians on general contouring (critical structures and target delineation) by comparing their contouring to user-defined standards or for periodic quality assurance testing of anatomy auto-segmentation routines and systems by comparing auto-segmented volumes to user defined standards. In addition the present invention may be used to make assessments of anatomy auto-segmentation routines or systems prior to customer purchase or clinical application or for the assessment of auto-segmentation routines or systems against updated and new imaging technology. The output of the system (e.g., the segmentation of valuations) as indicated by process block 140 of FIG. 3 , may also be used to assess whether a new treatment plan should be prepared based on changes in the internal anatomy of the patient during radiation therapy reflected in the new segmentation. It is specifically intended that the present invention not be limited to the embodiments and illustrations contained herein, but include modified forms of those embodiments including portions of the embodiments and combinations of elements of different embodiments as come within the scope of the following claims

Segmentations used to describe structures to be treated by radiotherapy are evaluated by converting the segmentations into volume models and examining volume elements that are extra or missing in the volume model of the second segmentation with respect to the volume model of the first segmentation. This characterization of volume elements may be displayed graphically to show differences in segmentations for training or evaluation purposes and may be quantified by a metric method tallying volume elements as optionally weighted by distance from volume elements shared by the segmentation.

big_patent

RELATED U.S. PATENT APPLICATIONS The following U.S. Patent applications are related to the present invention. Apparatus and Method for Execution of Floating Point Operations, invented by Sridhar Samudrala, Victor Peng and Nachum M. Gavrielov, having Ser. No. 06/879,337, filed June 27, 1986 and assigned to the assignee of the present Application. Apparatus and Method for Accelerating Floating Point Addition and Subtraction Operations by Accelerating the Effective Subtraction Procedure, invented by Vijay Maheshwari, Sridhar Samudrala and Nachum Moshe Gavrielov, having Ser. No. 07/064,836 filed on June 19, 1987 and assigned to the assignee of the present Application. BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates generally to data processing systems and, more particularly, to the apparatus for executing the floating point operations of a data processing system. 2. Description of the Related Art Data processing systems are typically provided with the capability of manipulating numerical quantities stored in the floating point format. In the floating point format, a numerical quantity is represented by a fraction value and by an (exponent) argument value. The argument value represents the power to which the exponent base is raised, while the fraction value represents the number multiplying exponential portion of the number. The principal advantage of the floating point format is the increased range of numbers that can be manipulated in the data processing systems without instituting extraordinary procedures or conventions. A floating point processor capable of advantageously using the invention disclosed herein is described in "The MicroVAX 78132 Floating Point Chip" by William R. Bidermann, Amnon Fisher, Burton M. Leary, Robert J. Simcoe and William R. Wheeler, Digital Technical Journal, No. 2, March, 1986, pages 24-36. The floating point format has the disadvantage that the execution of addition and subtraction operations in this data format is more complex and requires a greater time period than the same operation in the standard data format. This complexity if the result of having to align fractions prior to their addition or subtraction so that the exponents are identical, and then potentially having to normalize the result, i.e., shifting the fraction of the resulting quantity until a logic "1" is stored in the most significant bit position and adjusting the argument of the exponent accordingly. Referring now to FIG. 1, the addition and subtraction operations are defined in terms of effective addition and effective subtraction operations which more correctly identify related operation sequences. The addition and subtraction operations 101 are grouped into an effective addition operation 102 and an effective subtraction operation 103. The effective addition operation 102 includes the operations of adding operands that have the same sign and subtracting operands that have different signs. The effective subtraction operation 103 includes the addition of operands with differing signs and the subtraction of operands with the same sign. Referring next to FIG. 2, the steps in performing the effective subtract operation, according to the related art, is shown. In step 201, the difference between the exponents is determined. Based on the difference between exponents, the logic signals representing the smaller operands are shifted until the arguments of the exponents representing the two operands are the same, i.e., the operand fractions are aligned, in step 202. In step 203, the aligned quantities are then subtracted. If the resulting quantity is negative, then the 2's complement must be calculated, i.e., the subtrahend was larger than the minuend in step 204. In step 205, the most significant non-zero bit position (i.e., the leading logic "1" signal) is determined. Based on this bit position, the resulting quantity operand, is normalized, the leading logic "1" signal is shifted to the most significant bit position and the argument of the exponent is adjusted accordingly in step 206. In step 207, the rounding of the resulting operand fraction is performed. As will be clear to those familiar with the implementation of floating point operations, the seven steps of the effective subtraction operation of FIG. 2 can require a relatively long time for their execution. A need has therefore been felt for a procedure and associated apparatus for accelerating the effective subtraction operation. FEATURES OF THE INVENTION It is an object of the present invention to provide an improved data processing system. It is a feature of the present invention to provide improved apparatus for the execution of floating point operations. It is another feature of the present invention to provide a technique for acceleration of the effective subtraction operation in a floating point unit. It is yet another feature of the present invention to use a difference between a subset of signals of the operand exponent arguments to accelerate an effective subtraction operation. It is still another feature of the present invention to begin an effective subtraction procedure based on the difference between a subset of operand exponent argument signals prior to the availability of the complete difference between the exponent arguments. SUMMARY OF THE INVENTION The aforementioned and other features are accomplished, according to the present invention, by providing a floating point execution that includes, in addition to the apparatus for determining the difference between operand exponential arguments, apparatus for determining the difference between a subset of the operand exponent arguments. The subset difference apparatus provides a result prior to a determination of the complete difference between the operand exponent arguments. The subset difference is used to begin subtraction of differences between operand fractions (or fractional portions thereof). The procedures are chosen such that when the complete operand argument difference is different from the subset operand argument difference, the correct result fraction is one of the operand fractions, a quantity that is available. These and other features of the present invention will be understood upon reading of the following description along with the drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates the relationship between the addition and subtraction operations and the effective addition and the effective subtraction operations. FIG. 2 illustrates the steps for performing the effective subtraction operation according to the related art. FIG. 3 illustrates the two procedures into which the effective subtract operations are divided in order to accelerate their execution. FIG. 4 illustrates the steps in the effective subtraction operation when the absolute value of the difference of the exponent arguments is greater than one. FIG. 5 illustrates the steps in the effective subtraction operation when the absolute value of the difference of the exponent arguments is less than or equal to one. FIG. 6A and FIG. 6B illustrate the effective subtraction flows initiated after determination of the difference between selected portions of the exponential arguments. FIG. 7 is a block diagram of the apparatus implementing the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENT Detailed Description of the Figures FIG. 1 and FIG. 2 have been described with reference to the related art. Referring to FIG. 3, the effective subtraction operation can be accelerated by first considering the situation where the absolute value of the difference in the arguments of the exponents of the two operands, or the absolute value of DELTA(E), is <1 (i.e., or 1) or is >1 (i.e., all other values), that is ABS{DELTA(E)}≦1 or ABS{DELTA(E)}>1. Referring next to FIG. 4, the situation where ABS{DELTA(E)}>1 is examined in more detail. Comparing FIG. 4 with FIG. 2, the determination of the difference in the arguments of the exponents is performed in each case, in step 201 and in step 401. However, because the larger operand is identified, the subtraction operation, performed in steps 203 and 403 can be performed to insure that a positive resultant quantity is obtained by the operation, obviating, in the process illustrated in FIG. 4, the necessity of a step equivalent to the step 204 for the negation of the resulting operand. Because of the amount of the difference between operands, the result that the normalization will require a shift of at most one bit position for the resulting operand. A one bit position shift does not require a separate step and the detection of the leading logic "1" signal in step 404A, the normalization in step 404B and the rounding operation in step 404C can be considered a single time consuming step 404 rather than three time consuming steps (i.e., step 205, 206 and 207) in FIG. 2. Referring next to FIG. 5, the technique for reducing the time to execute (i.e., by accelerating) the effective subtraction operation when ABS{DELTA(E)}≦1 is shown. In step 501, the difference between the exponent arguments is determined. Because of the small difference in the arguments, the alignment of the fractions in step 502 can be performed without requiring a separate step (or "on the fly") before performing the subtraction step 503. The negation step 504 can be required, but either the normalization step 506 or the rounding step 507 is required, but not both steps. The procedure reduces the seven major steps to five major steps by the floating point apparatus. Referring next to FIG. 6A, the results of determining the difference, TDELTA(E), between the (six) least significant position subset of the operand exponent argument, the operation involving the operand fractions initiated as a result TDELTA(E), the correct DELTA(E) and the final fraction result are shown. When, for example the TDELTA(E)=0, then the operation for determining FRACTION A -FRACTION B is begun. The result of calculating DELTA(E) can take only one of three values, i.e., 0, > or =64, and <- or =64. When DELTA(E)=0, then the correct final fraction is FRACTION A -FRACTION B . When DELTA(E)> or =64, then the correct final fraction =FRACTION A . When DELTA(E)≦-64, then the correct final fraction result is FRACTION B . FRACTION A and FRACTION B are available and no computation is necessary to provide these results. These operand fractions are correct because the operand fraction typically (but not necessarily) includes only 53 positions, so a shift by 64 or more positions reduces the associated operand fraction to 0. Similarly, when TDELTA(E)=1, the computation of the final fraction result FRACTION A -FRACTION B /2 is initiated. When this final fraction result is not correct, based on the calculation of DELTA(E), the correct final fraction result will be either FRACTION A or FRACTION B . When TDELTA(E)=-1, the computation of the final fraction FRACTION B -FRACTION A /2 is begun. If this fraction is incorrect, the correct final fraction result will be FRACTION A or FRACTION B as indicated in FIG. 6A. When DELTA(E) takes on a value different from 0, 1 and -1, FIG. 6A lists the correct final fraction results under `other` as a function of DELTA(E). In order to accelerate the computation of the final fraction result, several techniques can be employed, the technique of the preferred embodiment being shown in FIG. 6B. In this technique, a difference T7DELTA(E) is calculated, being the difference between the seven least significant bit signals of the operand exponent argument. When TDELTA(E)>1 and < or =62, and T7DELTA(E)>1 and < or =62, then the computation of the final fraction FRACTION A -{FRACTION B /2 T7DELTA (E) } is initiated. This quantity will be correct when DELTA(E)>1 and < or =62. Otherwise, FRACTION A is used when DELTA(E)>129 and FRACTION B is used when DELTA(E) < or =-66. When TDELTA(E)>1 and < or =62 and T7DELTA(E)> or =66 and <127, then computation is begun on the final fraction result FRACTION B -{FRACTION A /2 -T7DELTA (E) }. This final fraction result will be correct when DELTA(E)> or =-62 and <-1. Otherwise, the final fraction result will be FRACTION A when DELTA(E)> or =66 or FRACTION B when DELTA(E)<-129. Referring next to FIG. 7, the apparatus implementing the procedures of FIG. 6A and FIG. 6B is shown. The 7 least significant bits (1 sbs) of operand exponent argument E A and the 7 least significant bits of operand exponent E B are applied to (7 bit) subtraction unit 76'. The 6 least significant bit difference, also referred to as TDELTA(E), is applied to detection and logic unit 72, while the 7 bit difference between E A and E B , also referred to as T7DELTA(E) is applied to shift and selection logic unit 74. The shift and selection logic unit 74 also has the operand fractions FRACTION A (F A ) and FRACTION B (F B ) and a control signal from detection logic unit 72 applied thereto. The detection logic unit 72, based on TDELTA(E), can make the decision between the 1, -1, 0 and other procedures of FIG. 6A. The shift and selection logic unit 74, based on T7DELTA(E), selects the procedures outlined in FIG. 6B. The output signals X A and X B from shift and logic unit 74 are the individual quantities in the final fraction column of FIG. 6B, i.e., the quantities determined when TDELTA(E)>1 and < or =62 and when T7DELTA(E)>1 and < or =62 or when T7DELTA(E)> or =-62 and <-1. The output signals X A and X B from shift and selection logic unit 74 are applied to subtraction unit 75. Selection logic unit 73 receives the operand fraction signals F A and F B and control signals from detection logic unit 72. The selection logic unit 73 determines the components of the final fraction result calculation illustrated in the final fraction result column of FIG. 6A. The output signals of the selection logic unit 73, X A and X B , are applied to subtraction unit 75. The control signals from detection logic unit 72 determine whether the output signals from selection logic unit 73 or the output signals from shift and selection logic unit 74 are applied to subtraction unit 75. The result of the operation of the subtraction unit 75, Y, is applied to selection logic unit 77 along with the operand fractions F A and F B . The operand exponent arguments E A and E B are applied to (11 bit) subtraction unit 76 where DELTA(E) is calculated. DELTA(E), the output signal from subtraction unit 76, is applied to detection logic unit 78. The detection logic unit 78, based on DELTA(E), selects the operand fractions, F A or F B or the output signal of the subtraction unit 75 as the final fraction result (Z). In the preferred embodiment, subtraction units 76 and 76' are implemented in the same piece of apparatus, the 6 1 sb signals and the 7 1 sb signals being available prior to the complete 11 bit difference being determined. Operation of the Preferred Embodiment When the effective subtraction operation is performed, the value of the difference between the exponent arguments is required to specify the operation involving the operand fractions. The present invention accelerates the effective subtraction operation by calculating a difference between an subset of signal positions of an operand exponent argument. Based on the operand exponent argument subset difference, a difference in the operand fractions (or fractional portion thereof) is determined during the time that the difference between the complete operand exponent arguments is being calculated. The subset is chosen so that when the complete difference is determined and the current procedure determined to be the incorrect procedure, the correct resulting fraction is available. This availability is accomplished by providing that, when the operand fractions are shifted by an amount represented by any operand argument position not in the subset, the shifted operand fraction has a value of zero. Therefore, the non-shifted operand fraction is all that remains and becomes the final resulting fraction. The difference in the operand argument subsets can identify the only combination of operand fractions for which an operation (subtraction) must be performed. This operation requiring a calculation is initiated prior to the determination of the difference between the complete operand arguments. Thus, when the difference between the complete operand arguments is available, the final fraction result, if a calculation is required, will be at least in progress, thereby accelerating the computation. The other possible final fraction results are operand fractions and are available based on the differences between the complete operand exponent arguments. The foregoing description is included to illustrate the operation of the preferred embodiment and is not meant to limit the scope of the invention. The scope of the invention is to be limited only by the following claims. From the foregoing description, many variations will be apparent to those skilled in the art that would yet be encompassed by the spirit and scope of the invention.

The arithmetic operations performed for floating point format numbers involve procedures having a multiplicity of major steps. In the performance of the effective subtraction operation, the determination of absolute value of the difference between the operand exponent arguments must be obtained in order to determine the correct procedure. In the present invention, a difference between a subset of the operand exponent arguments is calculated and the result of this calculation is used to anticipate the correct procedure. By careful selection of the anticipated correct procedure, when the selection is erroneous, the correct result is immediately available. The availabilty of the correct result is achieved by selecting the subset of operand exponent arguments so that, in the event that the result is erroneous, the correct difference is such that the associated operand fraction (i.e., to be shifted by the amount of the difference) is shifted completely out of the operand fraction field (stored in a register).

big_patent

CROSS REFERENCE TO RELATED APPLICATION This application claims priority to U.S. Provisional Patent Application No. 61/089,989, filed Aug. 19, 2008, which is incorporated herein by reference. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the collection of blood and medical specimens, for example, in a medical facility, such as a hospital. 2. Description of Related Art In today's hospitals, mislabeling of specimen tubes, vials, or collection containers is a common problem that poses grave medical risk to a patient and potentially high liability to the institution. Despite best efforts at training and automation of the process with computers and barcodes, errors persist. The number of specimens collected and blood draws is quite high for a typical hospital. Error rates at or close to zero have been an unachievable goal. Mislabeling errors can include: wrong patient name; missing label; mis-communicated order; outdated tube, vial, or container; unreadable, smudged, or bruised label; tube, vial, or container not labeled at bedside in accordance with applicable standards; and contamination while handling tube, vial, or container to add label. For the purpose of simplicity, hereinafter, the word “vial” will be utilized to describe the prior art in the present invention, and it is to be understood that “vial” means any specimen collection vessel deemed suitable and/or desirable by one skilled in the art for the collection of a specimen from a patient. Accordingly, “vial” is to be understood as being, without limitation, a vial, a tube, or a container. Staff that attach labels to specimen vials in most modern hospitals can include: a floor nurse; a phlebotomist; a patient care technician; an emergency room nurse; an operating room nurse; a surgical floor nurse; and a lab technician. The core problem has been identified to involve: failure to verify patient identity typically at the bedside; failure to use two forms of patient identity independent of a medical record number; and failure to verify that the patient identity matches the patient information on the printed label to be attached to the specimen vial. Most hospitals use a wrist (or ankle) identification (ID) band to identify each patient with information that at minimum includes the patient's name and date of birth. Modern hospitals either use or are considering using a barcode to encode this and possibly other patient information on the ID band at registration to automate the capture of the patient's information without human error. Although barcodes on ID bands work well after registration, some emergency room (ER) trauma patients are moved immediately to a bed where a specimen is drawn in anticipation of a medical doctor (MD) order and prior to full registration where the barcoded ID band is produced. These patients may use a handwritten ID band or an ID band without a barcode. Mistakes in getting the correct label onto the proper specimen vial are well documented. Unused full blood vials drawn in anticipation of an MD order are also at high risk of being labeled for the wrong patient as patients are moved with some frequency in the ER. In the rest of the hospital, i.e., other than the ER, a typical, prior art flow diagram for collecting a specimen is shown in FIG. 1 . The many types of specimens that are routinely collected are shown in FIG. 2 . With reference to FIG. 1 , a method of collecting a specimen (e.g., a blood specimen) in accordance with the prior art includes step 2 , where a suitable medical professional, e.g., a medical doctor (MD), a physician's assistant, etc., places an order to draw the blood specimen from a patient who is desirably already wearing a conventional ID band that includes at least the patient's name and date of birth, but which may not include any computer-readable code, such as, without limitation, a patient barcode. After the order is placed in step 2 , the method advances to step 4 where the order to draw the blood specimen from the patient is entered into a computer in any suitable and/or desirable manner, e.g., without limitation, by a data entry person. Thereafter, the method advances to step 6 where barcode labels associated with the order are printed. These printed barcode labels may include one or more of the following: one or more order barcode labels, one or more patient barcode labels, and/or one or more vial barcode labels to be applied to one or more specimen vials that either will receive or have already received a specimen. Thereafter, in step 8 , the barcode labels printed in step 4 are retrieved, perhaps from a printer that has also printed other, unrelated barcode labels. In step 10 , these retrieved barcode labels and the patient are brought together (e.g., in the patient's room) where, in step 12 , the specimen-taker determines whether the patient is wearing an ID band. If not, the method advances to step 14 where appropriate corrective action is taken to prepare an ID band for the patient and fasten it to the patient. From either step 12 or step 14 , the method advances to step 16 where the specimen-taker manually compares information on the patient's ID band to like information on the printed barcode labels. This information desirably includes, among other things, a medical record number, the patient's name, and the patient's date of birth. If, in step 18 , the specimen-taker determines that the information on the patient's ID band does not match like information on the printed barcode labels, the method advances to step 20 where appropriate corrective action is taken to make the information on the patient's ID band and the like information on the printed barcode labels match. From either step 18 or step 20 , the method advances to step 22 where the specimen-taker collects the specimen (in this example a blood specimen) in one or more specimen vials. In step 24 , the specimen-taker applies at least one of printed vial barcode labels to each specimen containing vial. In practice, the order of steps 22 and 24 may be reversed. Once each specimen vial contains a specimen and has one of the printed vial barcode labels applied thereto, the specimen vial is sent to the lab for analysis of the specimen. In view of the prior art method of collecting a specimen described above being known to result in mislabeling of specimen vials, it would be desirable to provide a method and system that reduces or avoids such mislabeling of specimen vials. SUMMARY OF THE INVENTION Disclosed is a method of tracking a specimen acquired from a patient. The method comprises: (a) storing in a computer storage accessible by a standalone or networked computer a first machine-readable code present on an identification (ID) means worn by a patient; (b) storing in the computer storage a second machine-readable code associated with an order to obtain a specimen from the patient; (c) storing in the computer storage a third machine-readable code present on an identification (ID) means worn by a specimen-taker; (d) following steps (a)-(c), selecting from a plurality of specimen containers having machine-readable codes that are unique to each other preapplied thereto one specimen container including a fourth machine-readable code preapplied thereto; (e) in response to an electronic reading means reading and dispatching to a processor of the computer the first—fourth machine-readable codes present on the ID means worn by the patient, present on the order, present on the ID means worn by the specimen-taker, and present on the specimen container, respectively, and in response to the processor determining that the first machine-readable code and the second machine-readable code are related to the same patient, the processor causing said first—fourth machine-readable codes to be stored in the computer storage in a relational manner and the processor of the computer causing a signal to be generated to acquire a specimen from the patient and to place the acquired specimen in the container; and (f) responsive to the processor receiving a signal that the specimen has been placed in the container following step (e), the processor causing an indication thereof to be stored in the computer storage in a relational manner with said first—fourth machine-readable codes. The method can further include: (g) in response to the electronic reading means reading and dispatching to the processor of the computer a fifth machine-readable code that is preapplied to another specimen container selected from the plurality of specimen containers, said processor causing the first, second, third, and fifth machine-readable codes to be stored in the computer storage in a relational manner; and (h) responsive to the processor receiving a signal that the other specimen has been placed in the other container following step (g), the processor causing an indication thereof to be stored in the computer storage in a relational manner with said first, second, third, and fifth machine-readable codes. Each machine-readable code can be unique of the other machine-readable codes. Step (f) can include the processor determining whether the signal of step (f) is received within a predetermined time interval of the processor generating the signal of step (e) and storing an indication thereof in the computer storage in a relational manner with said first—fourth machine-readable codes. Each machine-readable code can comprise a unique barcode. The ID means worn by the patient can be a bracelet. The ID means worn by the specimen-taker can be a badge. The first machine-readable code can comprise a barcode that encodes at least one of the following: a unique serial number; the patient's name; a registration number assigned to the patient; the patient's date of birth; the patient's sex; a code that signifies the type if ID means worn by the patient; and a check digit. The fourth machine-readable code can comprise a barcode that encodes at least one of the following: a unique serial number; an expiration date; a color of a lid or cap that specifies the type of specimen the container is to be used for; human readable numbers and/or characters corresponding to one or more of the unique serial number, the expiration date, and the color of the lid; and a check digit. The second machine-readable code can comprise a barcode that encodes at least one of the following: an order number; a type of specimen to be acquired; a volume of the specimen to be acquired; a time that the specimen is to be acquired; and a control number. The electronic reading means can be an optical scanner that is communicatively coupled with the computer via a wired or wireless connection. The optical scanner can be a barcode scanner. Also disclosed is a method of tracking a specimen acquired from a patient. The method comprises: (a) storing in a computer storage of a computer a first machine-readable code present on an identification (ID) means worn by a patient; (b) storing in the computer storage of the computer a second machine-readable code associated with an order to obtain a specimen from the patient; (c) storing in the computer storage of the computer a third machine-readable code present on an identification (ID) means worn by a specimen-taker; (d) following steps (a)-(c), selecting from a plurality of specimen containers having machine-readable codes that are unique to each other preapplied thereto one specimen container including a fourth machine-readable code preapplied thereto, wherein the fourth machine-readable code comprises a barcode that encodes a unique serial number and an expiration date of the container; (e) in response to receiving the fourth machine-readable code from an electronic reading means, a processor of the computer determining from the expiration date encoded in the fourth machine-readable code if the specimen container is out-of-date and, if so, causing an alert signal indicative of said out-of-date condition to be generated by or near the electronic reading means, otherwise, if the specimen container is not out-of-date, and in response to the processor determining that the first machine-readable code and the second machine-readable code are related to the same patient, the processor causing the first—fourth machine-readable codes to be stored in the computer storage in a relational manner and the processor causing a signal to be generated to acquire a specimen from the patient and to place the acquired specimen in the container; and (f) responsive to the processor receiving a signal that the specimen has been placed in the container following step (e), the processor causing an indication thereof to be stored in the computer storage in a relational manner with said first—fourth machine-readable codes. The method can further include: (g) in response to receiving from the electronic reading means a fifth machine-readable code that is preapplied to another specimen container selected from the plurality of specimen containers, said processor causing the first, second, third, and fifth machine-readable codes to be stored in the computer storage in a relational manner; and (h) responsive to the processor receiving a signal that the other specimen has been placed in the other container following step (g), the processor causing an indication thereof to be stored in the computer storage in a relational manner with said first, second, third, and fifth machine-readable codes. Each machine-readable code can be unique of the other machine-readable codes. Step (f) can include the processor determining whether the signal of step (f) is received within a predetermined time interval of the processor generating the signal of step (e) and storing an indication thereof in the computer storage in a relational manner with said first—fourth machine-readable codes. Each machine-readable code can comprise a unique barcode. The ID means worn by the patient can be a bracelet. The ID means worn by the specimen-taker can be a badge. The first machine-readable code can comprise a barcode that encodes at least one of the following: a unique serial number; the patient's name; a registration number assigned to the patient; the patient's date of birth; the patient's sex; a code that signifies the type if ID means worn by the patient; and a check digit. The fourth machine-readable code can comprise a barcode that encodes at least one of the following: a unique serial number; an expiration date; a color of a lid or cap that specifies the type of specimen the container is to be used for; human readable numbers and/or characters corresponding to one or more of the unique serial number, the expiration date, and the color of the lid; and a check digit. The second machine-readable code can comprise a barcode that encodes at least one of the following: an order number; a type of specimen to be acquired; a volume of the specimen to be acquired; a time that the specimen is to be acquired; and a control number. The electronic reading means can be an optical scanner that is communicatively coupled with the computer via a wired or wireless connection. The optical scanner can be a barcode scanner. Lastly, disclosed is a system for tracking one or more specimens acquired from a patient, wherein a standalone or networked computer is in operative communication with a computer storage and an electronic reading means that is operative for reading unique machine-readable codes disposed on the following: an identification (ID) means worn by a patient, an order to obtain the one or more specimens from the patient, an identification (ID) means worn by a specimen-taker, and a plurality of specimen containers each for receiving one specimen from the patient. The electronic reading means is also operative for dispatching said machine-readable codes to the processor which, in response to the machine-readable codes for the patient ID means and the order being related to the same patient, stores the machine-readable code for each specimen container to receive a specimen in the computer storage in a relational manner with the machine-readable codes for the patient ID means, the order, and the specimen-taker ID means, and generates a signal to acquire a specimen from the patient and to place the acquired specimen in the container. The computer is responsive to a signal that a specimen that has been placed in each specimen container for storing an indication thereof in the computer storage in a relational manner with the machine-readable code for each specimen container that received the specimen stored in the computer storage. Each specimen container of the plurality of specimen containers has a machine-readable code preapplied thereon that is unique from the machine-readable code preapplied to any other of the specimen containers and the machine-readable codes disposed on the patient ID means, the order, and the specimen-taker ID means. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flow diagram of a prior art method for collecting a specimen; FIG. 2 is a list of exemplary patient specimens that are routinely collected; FIG. 3 is a block diagram of an exemplary computer that can be utilized to implement the present invention; and FIG. 4 is a flow diagram of a method for collecting a specimen in accordance with the present invention. DETAILED DESCRIPTION OF THE INVENTION With reference to FIG. 3 , the present invention is embodied, at least in part, in a software program which executes on one or more standalone or networked computers 62 . Each computer 62 is coupled, either directly or via a wired or wireless computer network, to a local or remote computer storage 66 , such as RAM memory, FLASH memory, a Hard Disk Drive, etc., of the type known in the art. Each computer 62 can also include a media drive 70 , such as a CD-ROM drive, and the like, which can operate with a portable computer storage 72 , e.g., a CD-ROM, capable of storing computer software, data, and the like. Each computer 62 includes at least one microprocessor 64 or other such processing means that enables computer 62 to process and store data in computer storage 66 or computer storage 72 under the control of the software program, which operates under the control of a computer operating system, that controls the operation of computer 62 to process data, store data, and output data in human readable format (via print or visual display) in a manner known in the art. The software program can be stored in computer storage 66 , computer storage 72 , or some combination of computer storages 66 and 72 . The software program is able to configure and operate computer 62 in a manner to implement some or all of the present invention. Each computer 62 can include an input/output system 78 that can include, among other things, a keyboard 84 , a mouse 86 , and/or a display 88 . Computer 62 is exemplary of a computer that is capable of executing the software program of the present invention and is not to be construed as limiting the invention. With reference to FIG. 4 and with continuing reference to FIG. 3 , a method of collecting a specimen in accordance with the present invention includes a step 32 where a suitable medical professional, e.g., a medical doctor, a physician's assistant, etc., places an order to draw the specimen, e.g., a blood specimen, from a patient who is desirably already wearing an ID band 92 that desirably includes a computer generated patient barcode number 92 ′ that is unique to the patient, i.e., no two patients currently in the medical facility are assigned the same patient barcode number. As used herein, “barcode number” may include an alpha, numeric, or alphanumeric sequence. At or about the time the computer generates the patient barcode number 92 ′ on ID band 92 , the processor of the computer creates in the computer storage a database data structure where the patient's information, e.g., the patient's name and the patient's date of birth, are stored in a relational manner with the patient's barcode number. The patient's information can be entered in any suitable and/or desirable manner, e.g., without limitation, by order entry personnel, at or about the time the patient is accepted into the medical facility. After the order is placed in step 32 , the method advances to step 34 where an order to draw the blood specimen from the patient is entered into the computer in any suitable and/or desirable manner, e.g., without limitation, by data entry personnel such as a lab clerk. At or about the time the order to draw the blood specimen is entered, the processor of the computer generates a unique order barcode number 94 ′ and stores this order barcode number 94 ′ in a relational manner in the database data structure where the patient's information and the patient's barcode number 92 ′ are stored in a relational manner. Desirably, no two orders currently in the medical facility are assigned the same order barcode 94 ′. In step 36 , the computer, either automatically or under the control of the data entry person, generates a hard copy of the order 94 that includes the unique computer assigned order barcode 94 ′, some or all of the patient's information, and, optionally, the patient's barcode number 92 ′. The alpha, numeric, or alphanumeric sequence represented by each barcode number described herein may appear in conventional human readable form, i.e., letters, numbers, etc., next to each hardcopy of the barcode number to facilitate manual entry of the barcode number. At this point in time, the computer storage includes the database data structure where the patient's information, the order barcode number 94 ′, and the patient's barcode number 92 ′ are stored in a relational manner. Because the combination of at least the patient's barcode number 92 ′ and the order barcode number 94 ′ are unique with respect to all other combinations of patient barcode numbers and order barcode numbers present in the medical facility, no other data structure having the same patient barcode number and order barcode number should exist in the computer storage. In step 38 , the printed order 94 , including unique order barcode number and, desirably, some or all of the patient's information, along with suitable blood drawing supplies are brought to the patient (e.g., at the patient's bedside) where, in step 40 , the blood drawer (or blood-taker) determines whether the patient is wearing an ID band 92 that includes a unique patient barcode number 92 ′. To determine whether the patient's barcode number 92 ′ is unique, the barcode number on the ID band is input into the computer whereupon the processor compares said input patient barcode number 92 ′ to each other patient barcode number stored in data structures in the computer storage. If the patient is either not wearing an ID band or is wearing an ID band that the processor determines does not have a unique patient barcode number, an ID band having a unique patient barcode number is prepared for the patient and fastened to the patient in step 42 . The ID band can include, without limitation, a wrist band, an ankle band, and the like. Following either step 40 or step 42 , the patient barcode 92 ′ on the patient's ID band 92 is input into the computer in step 44 . As used herein, “input into the computer” means that a barcode number is either manually input into the computer (e.g., without limitation, via a keyboard, a computer mouse, and/or any other suitable and/or desirable manual input means) or is read by a suitable barcode reading means, e.g., barcode reader 90 in FIG. 3 , that communicates the read barcode number to the processor of the computer which is in communication with the barcode reading means and which is operatively coupled to the computer storage. Each barcode number represents a machine-readable code that can be read by the suitable reading means, in this case barcode reading means 90 . In steps 46 , 48 , and 50 the order barcode number 94 ′ on the order 94 is input into the computer, a badge barcode number 96 ′ present on a badge 96 of the blood drawer is input into the computer, and one or more barcode number(s) 98 ′ preapplied to specimen vial(s) 98 where the drawn blood is to be stored is/are input into the computer, respectively. Each barcode number input into the computer is stored at least temporarily by the processor in the computer storage. The order of input of barcode numbers into the computer in steps 44 , 46 , 48 and 50 is not to be construed as limiting the invention. Each barcode number (albeit, patient barcode number 92 ′, order barcode number 94 ′, blood drawer barcode number 96 ′, and vial barcode number 98 ′) is unique and, more specifically, each vial has a unique vial barcode number 98 ′ preapplied thereto. In step 52 , the processor determines if a database data structure exists that includes the patient's barcode number 92 ′ input into the computer in step 44 and order barcode number 94 ′ input into the computer in step 46 . In other words, the processor determines if the patient's barcode number 92 ′ and the order barcode number 94 ′ are related to the same patient. If so, the processor causes the barcode number 96 ′ on the badge 96 of the blood drawer input into the computer in step 48 and each barcode number 98 ′ preapplied to a vial 98 that was input into the computer in step 50 to be stored in a relational manner in the database data structure with the patient's barcode number 92 ′ and the order barcode number 94 ′. Desirably, the barcode number 96 ′ on the badge 96 of the blood drawer input into the computer in step 48 and each vial barcode number 98 ′ preapplied to a vial 98 that was input into the computer in step 50 are stored in the same database data structure where the patient's barcode number 92 ′ and the order barcode number 94 ′ were previously stored in a relational manner. However, this is not to be construed as limiting the invention since it is envisioned that each vial barcode number 98 ′ can be stored in a separate database data structure in a relational manner with the patient barcode number 92 ′, the order barcode number 94 ′, and the blood drawer barcode number 96 ′ if desired. Thus, each database data structure can store one vial barcode number 98 ′ or more than one vial barcode number 98 ′ in a relational manner with the corresponding patient barcode number 92 ′, order barcode number 94 ′, and blood drawer barcode number 96 ′. On the other hand, should the processor determine that the patient's barcode number 92 ′ and the order barcode number 94 ′ are not related to the same patient in the data structure where these barcodes were previously stored, the method advances from step 52 to step 54 where any discrepancy in the relationship between the patient's barcode number 92 ′ and the order barcode number 94 ′ in the data structure is corrected. At this point in time, the computer storage includes the database data structure where the patient's information, the order barcode number 94 ′, the patient's barcode number 92 ′, the blood drawer's barcode number 96 ′, and each vial barcode number 98 ′ are stored in a relational manner. Following either step 52 or 54 , the method advances to step 56 where the processor causes one or more suitable signals (audio, visual, or both) to be output that informs the blood drawer to draw the blood sample and send it to a lab for analysis. At or about the time the signal is output in step 56 , the processor starts a software or hardware timer that is utilized to determine that the blood draw is completed within a predetermined time after the signal is output in step 56 . When collection of the blood specimen in one specimen vial 98 or two or more specimen vials 98 is complete, the blood drawer causes an indication thereof to be input into the computer where the processor stores this indication in a relational manner with the patient's information, the order barcode number 94 ′, the patient's barcode number 92 ′, the blood drawer's barcode number 96 ′, and each vial barcode number 98 ′. The processor compares the time between when the signal is output in step 56 and the time when the blood drawer causes the indication that the collection of the blood specimen is complete to be input into the computer (i.e., the specimen collection time) to the predetermined time. The specimen collection time is desirably stored in a relational manner in the same database data structure where the patient's information, the order barcode number 94 ′, the patient's barcode number 92 ′, the blood drawer's barcode number 96 ′, and each vial barcode number 98 ′ are stored in a relational manner. Thus, upon completion of the blood draw, a complete record of the blood drawing event resides in a relational manner in the database data structure stored in the computer storage. If the specimen collection time exceeds the predetermined time, the processor can optionally cause a suitable signal to be output that informs the blood drawer of this fact. The lab receiving each vial 98 containing a blood sample has all of the order and “label” information stored in the database data structure that is linked to the vial barcode number 98 ′ preprinted on each vial and can process the order with confidence without producing any further paperwork or labels. Prior to executing the method shown in FIG. 4 , at least the patient barcode number 92 ′, the order barcode number 94 ′, and the blood drawer barcode number 96 ′ are stored in the computer storage. As discussed above, the relationship between the patient barcode number 92 ′, the order barcode number 94 ′, the blood drawer barcode number 96 ′, and each vial barcode number 98 ′ can be stored in the database data structure that is stored in the computer storage. For example, in step 52 of the method shown in FIG. 4 , in response to barcode reader 90 reading and dispatching to a processor of the computer the patient barcode number 92 ′, the order barcode number 94 ′, the blood drawer barcode number 96 ′, and the barcode number 98 ′ of each vial utilized to collect a sample, and in response to the processor determining that the patient barcode number 92 ′ and the order barcode number 94 ′ are related to the same patient, the processor stores the patient barcode number 92 ′, the order barcode number 94 ′, the blood drawer barcode number 96 ′, and each specimen vial barcode number 98 ′ to be stored in a relational manner in a database data structure that exists in the computer storage. The storage of these barcode numbers in a relational manner in a database data structure stored on the computer storage occurs only after it has been established that the patient barcode number 92 ′ and the order barcode number 94 ′ are related to the same patient. In the method described above, the relationship of the patient barcode number 92 ′ and the order barcode number 94 ′ to the same patient was made by way of these barcodes being stored in a relational manner in the database data structure stored in the computer storage. Thereafter, when the blood drawer barcode number 96 ′ and each specimen vial barcode number 98 is input into the computer, these latter barcode numbers 96 ′ and 98 ′ are stored in a relational manner in the same database data structure as the patient barcode number 92 ′ and the order barcode number 94 ′. However, this is not to be construed as limiting the invention since the determination that the patient barcode number 92 ′ and the order barcode number 94 ′ are related to the same patient can be made outside of the database data structure whereupon the database data structure is created that relates to various barcode numbers 92 ′, 94 ′, 96 ′, and 98 ′ in a relational manner at the time these barcode numbers are input into the computer in steps 44 - 50 . Desirably, the barcode number 96 ′ of the blood drawer (or specimen-taker) is stored in the computer storage prior to performing the steps of the method shown in FIG. 4 for security purposes and/or quality control purposes. Thus, if a specimen-taker is not qualified or is not authorized to acquire a particular specimen from a patient, the processor can cause a suitable error signal to be generated when the specimen-taker's badge barcode number 96 ′ is input in step 48 . As noted above, each barcode comprises a unique machine-readable code. The ID band worn by each patient can be in the form of a wrist or ankle bracelet. The badge of the blood drawer (or blood-taker) comprises an ID means that is worn by the blood drawer. The patient barcode number 92 ′ is desirably a machine-readable code that encodes one or more of the following: a unique serial number; the patient's name; a registration number assigned to the patient; the patient's date of birth; the patient's sex; a code that signifies the type of ID means worn by the patient (ankle or wrist bracelet); and a check digit. Each vial barcode number 98 ′ is desirably a machine-readable code that encodes one or more of the following: a unique serial number; an expiration date; a color of a lid or cap that specifies the type of specimen the container is to be used for; human readable numbers and/or characters corresponding to one or more digits of the unique serial number, the expiration date, and a check digit. The order barcode number 94 ′ is desirably a machine-readable code that encodes one or more of the following: an order number; a type of specimen to be acquired; a volume of the specimen to be acquired; a time when the specimen is to be acquired; and a control number. The barcode reading means 90 comprises an electronic reading means in the form of an optical barcode scanner that is communicatively coupled with the processor of the computer via a wired or wireless connection. As can be seen, the present invention provides a means of achieving a failsafe, zero defect process for identifying and processing patient specimen samples. It has the additional benefit of eliminating the cost of vial labels (since the vials have preprinted vial barcodes already attached thereto), associated printers, and staff labor in dealing with the vial labels. The invention has been described with reference to the preferred embodiment. Obvious modifications and alterations will occur to those of ordinary skill in the art upon reading and understanding the preceding detailed description. For example, the specimen collection system described above can be implemented in any suitable and/or desirable manner utilizing one or more standalone or networked computers and local or remote computer storage, all connected by a wired network, a wireless network, or some combination of a wired and wireless network. Moreover, while the invention has been described with reference to the drawing of a blood specimen, this is not to be construed as limiting the invention since it is envisioned that the invention can be utilized in connection with the acquisition of any type of biological specimen, such as, without limitation, each specimen type shown in FIG. 2 . It is intended that the invention be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.

In a method of tracking a specimen acquired from a patient, machine-readable codes present on a patient identification (ID), an order to obtain a specimen from the patient, and on a specimen-taker ID means, respectively, are stored in a computer storage. A specimen container having a fourth machine-readable code preapplied thereto is selected from a plurality of specimen containers having unique machine-readable codes preapplied thereto. In response to a processor determining that the first and second machine-readable codes are related to the same patient, the processor causes the first—fourth machine-readable codes to be relationally stored in the computer storage. Responsive to the processor receiving a signal that a specimen has been placed in the selected specimen container, the processor causes an indication thereof to be stored in the computer storage in a relational manner with the first—fourth machine-readable codes.

big_patent

CROSS-REFERENCE TO RELATED APPLICATION [0001] This application claims priority of U.S. provisional patent applications Ser. No. 60/679,525, filed May 10, 2005, and 60/756,259, filed Jan. 4, 2006. FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT [0002] Not Applicable. TECHNICAL FIELD [0003] This invention generally relates to a voice activated distance measuring device, such as for providing distance and other information to a golfer. BACKGROUND OF THE INVENTION [0004] Range finding devices, such as the SkyCaddie range finder sold by Skyhawke Technologies, LLC (see www.skygolfgps.com), are known and provide information to golfers, such as the distance to a golf pin. However such devices require manual requests for information and provide only visual display of the requested information, which can be cumbersome to the golfers. [0005] The present invention is provided to address this and other issues. BRIEF DESCRIPTION OF THE DRAWINGS [0006] FIG. 1 is a plan view of a printed circuit board in accordance with the invention; [0007] FIG. 2 is a perspective view of the printed circuit board assembly of FIG. 1 , mounted in the brim of a hat; and [0008] FIG. 3 is a view of the printed circuit board and brim of FIG. 2 , illustrating a recess in the brim to receive the printed circuit board assembly. DETAILED DESCRIPTION OF THE INVENTION [0009] While this invention is susceptible of embodiment in many different forms, there will be described herein in detail, specific embodiments thereof with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the specific embodiments illustrated. [0010] The present invention is a device that measure distances on a golf course and provides other relevant information. The device is useful for other applications, as well. The device uses voice recognition technology and GPS technology to provide a user, such as a golfer, with required data on the golf course and its parameters in a verbal electronically spoken form. The electronics and software for this device may be incorporated into an article of clothing, or other portable device, such as an article of headgear, including a golf hat or visor. The device may alternatively use distance measuring technology such as infra red, optics, Doppler acoustics and the like. [0011] The device uses commercially available GPS data, such as supplied by Sports Mapping, Inc., or similar company, providing golf course mapping data to convert GPS mapped longitude and latitude coordinates to measure distance and other factors. [0012] The device may use any GPS system available to measure the longitude and latitude coordinates to compute the distance and other golf course parameters. [0013] The device incorporates voice recognition technology to accept voice commands from the user which are sensed by a voice sensor, such as a bone conductance vibration sensor or a microphone, which drives the voice recognition software. The device responds to voice commands such as “distance,” “pin-placement,” or any other such word or words. [0014] Commands may also be in the form of an electrical signal from a switch or any electrical pulse generated by touch or remote control. [0015] The device incorporates voice synthesis technology to provide an audible output by electronically produced spoken words, to provide distance and other information to the user via a loudspeaker or headphone, following a verbal command from the user. The output acoustics can be adjusted for volume level and frequency filtered for any particular user requirement or application. The device may also provide in a verbal form other information such as the green size, pin placement and other information on the golf course parameters. [0016] The GPS and voice recognition electronics, for the GPS distance measurement and the voice recognition circuits and software, including the voice sensor, speaker and power source, may be incorporated into any design of headgear, such as a hat or visor, such as golf headgear, or any other article of clothing for golf or other sport. [0017] As an additional feature the device may also accept verbal or any other data input and memorize and compute this, when prompted by voice command or an electrical pulse generated by touch or remote control, to predict golf course user golf strategy, club selection, rules and other golf player needs. For example the user may verbally enter information, either directly or by a verbal prompt, such as the club selected for the shot. The GPS technology determines the actual distance traveled by the ball and its accuracy. Information regarding weather conditions, such as wind speed and wind direction, may also be provided. Over time the device may build a library of information regarding the golfer's personal shot results, such as how far does a ball typically travel, and how accurately, when hit with each club. The device may collate and memorize this information and function as an expert system to progressively learn the golfer's successes and failures to generate a strategic recommendation which may also be based on an algorithm which is developed for this system. In summary this information can be used to provide the golfer with recommendations for future golf shots based on the golfer's past performance. [0018] The bone conductance vibration sensor receives audio from the user directly from vibrations conducted through the skull of the user by direct mechanical contact of the sensor to the user's forehead. Such technology is superior to conventional microphones in that the user's voice is picked up clearly while substantially all external noise, such as but not limited to side chatter or wind noise, is rejected. There will be an increase in voice recognition accuracy achieved by the use of the bone conductance vibration sensor. [0019] The unique design of this device, in one possible form as a hat or similar headgear, facilitates direct contact of the bone conductance vibration sensor with the user's forehead, providing the headgear design a unique advantage. [0020] This device may also be used to provide pre recorded golf instructions to assist the golfer in making a specified golf shot, when prompted to do so by a voice recognition command. [0021] The device may be used for such applications as hiking, surveyors and hunters and other applications. The device may also be used for scuba divers using an underwater design which may use any latitude and longitude measurement technology. [0022] The device may be expanded to include its use in any portable application. [0023] The device may be provided with a communications method, such as but not limited to a serial, USB or wireless connection to a separate personal computer or similar technology provided by the user of this device. The device may be able to upload and download data to the separate computer to facilitate various detailed functions, if such functions are beyond the scope of the device by itself such as, but not limited to, graphical display of the users score and plot of all ball trajectories viewed against an image of the subject golf course, display of clubs used, comparative display of any other player or players using the system, expert system advice based on data accrued during one or more recorded games, printing of results and scorecards. The connection may also facilitate uploading of new course databases to the device and management thereof, training of voice recognition commands and management of those commands. [0024] A main printed circuit board (PCB) assembly 10 to reside in a brim 12 of a hat 14 is illustrated in FIGS. 1, 2 and 3 . The circuitry for the device is substantially mounted on the PCB assembly 10 . The PCB assembly 10 is seated in and supported by, a molded space 18 in a plastic brim stiffener 20 . The PCB assembly 10 is composed of three rigid printed circuit boards 10 a , 10 b , 10 c , connected by flexible flat cable 22 , so as to permit the PCB assembly 10 to follow the curvature of the brim 12 . [0025] The center PCB 10 b of the PCB assembly 10 has a connector extension 24 , 1 cm long, designed to extend through hat fabric and be accessible from the inside hat. [0026] Referring to FIG. 3 , a rectangular battery 26 is sewn into a compartment on a side of the hat 14 , positioned and padded for comfortable wear. Battery wiring 26 ′ runs through the hat and connects to the PCB assembly 10 using a channel detent 28 in the stiffener 20 (See FIG. 3 ). An internal headband area holds a transducer 30 , such as a bone conductance vibration sensor, supported by acoustic dampening material. The bone conductance vibration sensor will contact a wearer's forehead, with support elastic sewn in to assure the device maintains @20 g contact pressure, while maintaining comfort. Alternatively a conventional acoustical microphone could be utilized. [0027] Referring to FIG. 3 , the plastic brim insert stiffener 20 has the molded space 18 for the PCB assembly 10 . Two channels are cut out at the rear to allow for PCB connector and wiring channel. The brim 12 further includes a circular opening 38 for a down facing speaker. [0028] The top of the PCB assembly 10 is protected by layer of electrostatic protective padding material, and is finished in a fabric of similar weave and color to hat body. [0029] Bluetooth, a known and published radio frequency short range data/audio transfer technology, may be used in the device for five primary purposes, data transfers, as an audio server, as an audio client, short range audio communications and as a remote GPS. [0030] Externally sourced data transfers to the device's internal nonvolatile storage memory may be via a wired connection to the device's internal nonvolatile storage memory. Wireless installation of golf course data or program updates via Bluetooth or similar technology will allow such conveniences as allowing a golfer to upload golf course GPS coordinate data while in the pro shop or retail outlet without needing a wired connection or even removing the hat device from his/her head. This will facilitate and encourage users to purchase golf course files. [0031] The device may include Bluetooth technology, a conventional communication/data/audio transfer technology, for five primary purposes, data transfers, as an audio server, as an audio client, short range audio communications and as a remote GPS. [0032] As a Bluetooth audio server, it will be possible for the user to use a separate Bluetooth headset of the type used often in cell phones to access the voice recognition input and audio output of the device, without using the hat device's own built in speaker/voice sensor. This would enable the user to use the device even if the hat were not worn, or indeed if the device were not in a hat at all, and was implemented as any other form of wearable computer not requiring a built in speaker/voice sensor. [0033] As a Bluetooth audio client, the hat device's speaker/voice sensor could be used for an auxiliary headset for another Bluetooth audio server such as a cell phone, in the same manner a Bluetooth ear clip headset is currently used. [0034] As a short range audio communications client, it would be possible for two users of the device to maintain wireless audio communications providing they were in range typical of Bluetooth devices, usually 100 m maximum. [0035] As a remote GPS, it would be possible for a user to use the GPS contained in the hat device with another program which required a GPS by transmitting the coordinate data over the Bluetooth using known Bluetooth protocols for GPS data transmission. [0036] The device further permits a user to record geographic coordinates of a golf course, including its hazards and fairway boundaries, by use of a portable computing device equipped with a global positioning (GPS) device. Such recording can be done by, but not limited to, voice commands, keyboard, mouse or touch screen input. The device is running a program in the form of compiled computer code that continually receives updated latitude and longitude coordinates from the GPS, and on receiving input from the user, records those coordinates in permanent storage, such as but not limited to non-volatile memory or magnetic recording of a file on disk. [0037] The user in the process of recording the course travels physically to course locations such as but not limited to tee off points, fairway boundaries, sand trap boundaries, water boundaries and green boundaries. Upon physically reaching the exact geographic point desired, the user indicates the hole number of the course and the type of course location using an input method previously described. The geographic coordinates (latitude, longitude, altitude) are then appended to non-volatile storage as previously described. [0038] The golf course recording process will be designed in such a way as to allow the average person who is not necessarily an expert in computer or GPS technologies an easy method to record any golf course that s/he may wish to record, and allow for that course recording to be electronically transmitted to others for the purposes of sharing recorded courses and building up a shared collection of recorded courses. Upon completion of the recording of course features, the complete file containing multiple instance recordings of course name, hole number, hole feature and geographic location can be used to facilitate the calculation of geographic distances between the golfers current GPS position and those features, such as but not limited to the distance from the golfer to the center of the green. Other course feature recordings may be used also in the process of giving the golfer advice, by relating his/her current geographic position to those features. The recorded course data may also be used for other purposes, such as but not limited to information for greens keepers to assist in course maintenance or the production of maps or computer models. [0039] From the foregoing, it will be observed that numerous variations and modifications may be effected without departing from the spirit and scope of the invention. It is to be understood that no limitation with respect to the specific apparatus illustrated herein is intended or should be inferred. It is, of course, intended to cover by the appended claims all such modifications as fall within the scope of the claims.

A voice activated device for annunciating a message indicative of a distance of the device spaced from another location is disclosed. The device comprises a voice sensor for receiving a voice command requesting annunciation of a message indicative of the distance of the device spaced from the other location, converting circuitry coupled to the voice sensor for converting the received voice command to a corresponding electrical command, determining circuitry responsive to the electrical command for determining the distance of the device from the other location, and a speaker coupled to the determining circuitry for annunciating the message indicative of the determined distance of the device from the other location. The device may be used for informing a golfer of the golfer's distance from the pin.

big_patent

RELATED APPLICATION DATA [0001] The present application claims priority from provisional application Ser. No. 60/278,672 filed Mar. 20, 2001, which is also incorporated by reference herein. FIELD OF THE INVENTION [0002] The present invention relates to the field of semiconductor design technology, and in particular, to systems and techniques used for implementing circuit designs into silicon based integrated circuits (ICs). BACKGROUND [0003] In the field of semiconductor design technology, a design rule check (DRC) is a well-known process for inspecting whether mask pattern data of a semiconductor integrated circuit is correctly designed in compliance with fabricators' topological layout rules (TLR). The TLR are unique to each fabrication facility, or semiconductor wafer plant, based on available process technologies, equipment limitations, etc. An example of prior art DRC system is illustrated in U.S. Pat. No. 6,063,132 incorporated by reference herein. [0004] Integrated circuit designers transform circuit schematics to mask data by drawing polygons that represent the physical masks to be fabricated on silicon. For example, a transistor symbol on a circuit schematic could be represented by simply drawing a POLY layer polygon (gate region) crossing a DIFFUSION layer polygon (source and drain regions) and both polygons are laid within a WELL layer polygon. These mask pattern data are usually in well-known GDS format (binary) and are used by a design rule checker to check against design rules embodied in coded form in a design rule check command file. [0005] [0005]FIG. 1 illustrates the basic flow of design rule checking on mask pattern data of an integrated circuit in accordance with a prior art routine 100 . A design rule check (DRC) command file 120 is coded in accordance with a topological layout rule document 101 . DRC command file 120 and the mask pattern data 130 (representing the physical layout of the IC) are used as inputs by a design rule checker 140 (typically a software routine) for design error detection and to generate a results list. Any subsequent design errors detected must be corrected in the layout proposed by the IC designer as shown in block 150 . For some types of ICs, this process of checking the design errors can be automated, but for many others, it cannot. [0006] A recent development in the IC industry has been the incorporation of memory and logic within the same IC, as found for example in embedded memory systems, and in so-called system-on-chip (SOC) designs. These systems present a unique challenge to the design process, because memory and logic circuits have different sizing, performance and scaling issues when embodied in silicon. Thus, logic and memory layout regions they must be treated differently during the verification process. [0007] A first conventional method of checking design rules for an SOC design is described now with reference to the system 200 shown in FIG. 2. In the case of a semiconductor foundry (i.e., those plants that specialize in rendering third party designs into silicon) a design rule check command file 220 is written by referring to a Foundry's Topological Layout Rule document (TLR) 201 . Therefore, this design rule command file typically only consists of so-called “Logic Rules” 210 applicable to a logic section of a chip under consideration. As before the Mask Pattern Data 230 for the chip is fed into a design rule checker 240 to check against these logic rules. The output of this process is a design rule check result file 250 . [0008] At this point, the results consist of real logic error(s) 251 , false logic rule errors on memory blocks 252 and possibly real memory error(s) 253 . The false logic rule errors 252 are caused by the fact that logic circuits implemented in silicon typically require greater spacings, sizings and margins than memory circuits. An extra step 260 thus has to be carried out to filter false error(s) from the other real errors reported in the result database. The typical method is by manual effort—i.e., human eye review and filtering. This can be extremely time consuming and cumbersome since the number of false design rule errors will increase relative to the number of memory blocks used and the size of each memory instance. [0009] Thus, this approach flags many false DRC errors because each memory bit cells and associated leaf cells can cause many DRC violations that are not “true” because they do not actually violate a memory design rule that is applicable to the memory block. An operator has to manually check all the violations against a memory design rule check at step 270 to see if they are real errors. They then iteratively repeat this process to arrive at a set of real logic errors 271 , and real memory errors 272 . Nonetheless, this process can often cause real errors to be overlooked. Furthermore, this process slows down the design development cycle because each error must be discussed with the IC design supplier, and this interaction can be time consuming as it requires cooperation between the IC designer, the foundry field support engineers, and the foundry itself. [0010] A second conventional method of checking design rules is described below with system 300 referenced in FIG. 3, where like numbers are intended to denote like structures and operations unless otherwise noted. In this approach, a Cell Delete or Masking technique 310 masks out the whole memory instance including memory bit cell arrays and other associated logic support circuitry such as wordline decoder, sense amplifier, etc. from design rule checks performed by checker 340 on GDS file 330 . The design rule check (DRC) results 350 will thus consist only of real logic errors 351 . However, this method assumes the memory blocks used are DRC clean and that the interfaces (or intermediate regions) between the memory and logic parts satisfy logic rules. Consequently, it will not detect any real errors in such features. [0011] Accordingly, a substantial need exists in this field of art for an improved design verification tool that eliminates the aforementioned problems. SUMMARY OF THE INVENTION [0012] An object of the present invention, therefore, is to provide a design rule checking system and method that accurately reports appropriate errors for appropriate regions in a system that includes two different kinds of circuits, i.e., such as memory and logic. [0013] A related object is to eliminate false errors caused by design rule checking tools examining regions that are not subject to the same design rules supported by the design rule-checking tool. [0014] These objects are achieved by the present invention, which provides a system and method of checking design rules to determine whether or not a logic part (all non-memory devices that have to satisfy TLR) of a mask pattern data obeys logic rules (as specified in a TLR document) and the memory part of a mask pattern data obeys memory rules (in this case, logic rules that are modified appropriately for a memory area to accommodate the more liberal values available for such regions). This method helps users filter out false errors due to logic rule checks in a memory block, and further helps pinpoint real design rule errors in the mask pattern data. [0015] Another aspect of the invention covets the creation of customized rules appropriate for different types of memory regions that might be included on a chip, where such customized rules are based on modifying a standard logic rule by “pushing” more liberal memory based parameter on to a stricter logic based parameter. [0016] Yet another aspect of the invention pertains to a program that can be executed on any number of conventional computing systems for creating such customized rules, and/or for performing a design rule check on mask pattern data based on such customized rule sets. [0017] Still another aspect of the invention concerns a system configured with the above mentioned customized design rules and programs executing on a conventional computer system. [0018] In a preferred embodiment, the results are categorized in different categories in accordance with where they occur, such as in Logic, Bordered Single Port (BDSP) SRAM, Borderless Single Port (BLSP) SRAM, Dual Port (DP) SRAM and ROM groups. Furthermore it will more accurately detect and classify mistakes or any modifications made to standardized foundry bit cell designs as may be made by memory compiler vendors or layout engineers at the IC designer. [0019] The present invention should find significant usage in the semiconductor industry and similar industries (for example, LCD) where different design rules must be applied to different types of regions on a substrate. DESCRIPTION OF THE DRAWINGS [0020] [0020]FIG. 1 illustrates a general prior art process flow sequence for performing design rule checking on mask pattern data of an integrated circuit. [0021] [0021]FIG. 2 illustrates a flow diagram of steps performed by a 1 st prior art method for real Logic and Memory errors detection. [0022] [0022]FIG. 3 illustrates a flow diagram of steps performed by a 2 nd prior art method for real Logic errors detection. [0023] [0023]FIG. 4 illustrates a flow diagram of steps performed by a preferred embodiment of the present invention for Real Logic and Memory errors detection. [0024] [0024]FIG. 5 illustrates a flow diagram of steps performed by [this] the preferred embodiment of the invention for creating customized design rule check command files based on modifying a standard logic rule file to take into consideration minimum dimensional values extracted from memory bit cell design parameters. [0025] [0025]FIG. 6A illustrates the application of logic and memory rules within or between the logic and memory regions of a mask pattern data; [0026] [0026]FIG. 6B illustrates the relationship of various circuitry regions in a layout of an IC, and how such are treated by the present invention; [0027] [0027]FIGS. 7A to 7 C are examples of memory cell violations triggered by a standard logic rule against a variety of types of memory cells, and which violations are used to push appropriate minimum dimensional data onto a modified form of the logic rule to be used for designs utilizing such type of memory cell. DETAILED DESCRIPTION [0028] The present invention provides a solution to the disadvantages of the first and second conventional methods of checking design rules as explained above. From a broad perspective, the method generally applies the right set of rules to the right regions of the mask pattern data. To simplify the process (i.e., to avoid having to create an entire set of design rule checks from scratch, or to harmonize several different types of design rules from different memory cell vendors) and ensure its accuracy with respect to any particular set of foundry rules, the customized design rules are based on modifying a standard set of Logic Rules as needed to reflect needs of particular regions in the chip. Thus, a customized design rule is created for each different type of region that may be present on the chip, and this customized design rule is in fact simply based on pushing more liberal parameters onto stricter parameters contained in the standard Logic rules, and only in circumstances where it is necessary to do so. Accordingly, because different types of circuitry (logic, memory) may require different processing steps, lithographic constraints, etc., they can be treated independently by the present invention to ensure that design rules are accurately resolved for a system on chip integrated circuit design which uses a mix or blend of such circuitry. For instance, since memory circuits tend to be more aggressively sized and manufacturable than comparably sized and spaced logic designs, the former are subject to fewer layout constraints. These constraints include, among other things, minimum feature size, allowed feature shapes (i.e., avoiding notches and similar undesirable shapes), minimum distances between different types of feature shapes, etc. For example, a gate width might be smaller in a memory design than a logic design, and the minimum spacing between two signal lines may be smaller as well. Allowable contact sizes and feature shapes may vary from region to region. Other examples will be apparent to those skilled in the art. [0029] This system and method is described below with reference to FIG. 4. A system 400 includes a conventional computer system and various software routines and libraries for performing a design rule check as now explained. In particular, system 400 includes a standard logic design rule (for logic areas) 410 that is supplemented by additional customized logic rules 411 - 414 (for other types of areas such as specialized memory areas). One or more rules from this set are used to check a design in GDS form 430 , depending on the types of regions presented in the IC. For example, if logic and (BDSP) SRAM were included in a design, both of these design rules would be used by design rule checker 440 (a software routine operating on the computer system) to check different areas of an IC layout as explained below. As seen in FIG. 4, each type of memory has its own set of customized rules to check against with. Note that in FIG. 4, “BDSP SRAM” stands for Bordered Single Port Static Random Access Memory; “BLSP SRAM” stands for Borderless Single Port Static Random Access Memory; “DP SRAM” stands for Dual Port Static Random Access Memory and “ROM” stands for Read Only Memory. The result is that a design rule check result 450 includes a number of separate error reports for layout violations detected in a layer (or layers) of an IC, including 451 (for real logic errors) 452 (for real BDSP SRAM errors) 453 (for real BLSP SRAM errors) 454 (for teal DP SRAM errors) and 455 (for real ROM errors). Similar customized design rules could be created, of course, for embedded DRAM, flash, etc. The necessity for manual checking, and the possibility of so-called “false” errors, is substantially eliminated. This principle could be extended beyond just memories, of course, to include other design rules for other areas that have differing design rule requirements. [0030] A system 500 which derives the customized memory rules from standard logic design rules is shown in FIG. 5. Note that the system 500 also can be any conventional computing system appropriately configured with the libraries, files and routines explained herein, and in fact, in a preferred embodiment, is the same system as system 400 noted earlier. The first step performed by system 500 is to run a design rule check with checker 540 on a memory bit cell mask pattern data 530 (from the appropriate memory type) against a design rule command file 520 that consists of only standard foundry logic rules 510 . From this report 550 —an example of which is shown in FIG. 7A for a BDSP SRAM—a list of violations is created at 551 as presented by the bit cells. In other words, the various features of the memory cell are checked against standard logic rules to determine where they will fail, and to generate a comprehensive list of all possible errors. These errors are analyzed to determine how the standard logic rules 510 should be modified for a customized design rule set for the particular memory cell for this vendor. Thus, an analysis of the actual memory design rules of such memory cell is made at step 560 , and then the appropriate parameter (minimum dimension) is then “pushed” onto a modified form of the standard logic design rules to create a set of distinct and separate design rules 571 - 575 at step 570 . Further examples are illustrated in FIGS. 7B and 7C for BLSP and DP SRAM cells in such memories for a 0.18 micron design as tested against the present assignee's own generic design rules as published as of the current date (version 2.2 p0). It is apparent that different violations would be presented by different logic and memory design rules, so that different types of parameters would be pushed as needed onto standard logic rules when creating customized design rules. [0031] All these extracted values are used to derive customized memory rules ( 571 - 575 ) for each type of memories. Thus, this invention can be applied to any mask pattern database, including one having no memory blocks, or even multiple types of memory blocks. The only modification required to implement the present invention using conventional GDS formatted data is that different types of memory should be identified in some way, such as with different memory ID layers to defined core bit cell regions. This can be done in advance, by modifying the GDS data file directly, by adding a distinct memory ID layer on top of each type of memory to identify such different respective memory region types. [0032] Other techniques for identifying such layers will be apparent to those skilled in the art, and the present invention is by no means limited to any particular embodiment in this respect. The main goal is simply to ensure that design rule checker 540 is able to correlate a particular region in a layer with a particular set of design rules, and this can be accomplished in any number of ways either explicitly or implicitly. [0033] [0033]FIGS. 6A and 6B illustrate the relationships of different polygons on a mask pattern data, and shows how different design rules are effectuated on a layer 600 within the chip layout. For polygons 610 , 615 within a logic area 605 , logic rules 620 should be applied. For polygons 630 , 635 within a memory area 625 , memory rules 640 should be applied. For a polygon 660 that is an intermediate area, i.e., extending from a logic area 605 to a polygon within a memory area 625 , logic rules 620 are also applied in a preferred embodiment. This is because memory rules can only apply to polygons within the memory area due to different process impact. As suggested earlier, the conventional prior art methods do not and cannot distinguish between logic polygons and memory polygons within a layer. Therefore, the same set of rules is used to check against all polygons in a mask pattern data regardless of logic and memory regions, and this leads to improper results. [0034] The manner in which the invention checks different regions with different design rules is shown in FIG. 6B as follows. First, in a particular layer A 600 of a layout, a polygon 605 in a logic area is derived as A_logic whereas a polygon 625 of layer A in a memory area is derived as A_memory. To satisfy a foundry's design rules for implementing a design into silicon, some minimum geometric constraints or dimensions must be observed; these include: a) Minimum A_logic to A_logic spacing defined as logic_value; b) Minimum A_memory to A_memory spacing defined as memory_value; and c) Minimum spacing between A_logic and A_memory is also defined as logic_value. [0035] Accordingly, an appropriate standard logic design rule check is executed on region A_logic 605 using logic rules 571 , and not on any other region. A_logic is derived as (layer A NOT MEMORY). This yields any appropriate errors for this logic region of this layer, and is accurate for such region. Next, any memory regions 625 are treated (by examining their ID) in accordance with an appropriate memory region design rule ( 572 - 575 ). The A_memory layer is derived as (layer A AND layer MEMORY). This yields any appropriate errors for this memory region of this layer, and is accurate for such memory region. Any other memory regions are examined in the same way, with a design rule selected based on a particular memory ID. [0036] It is apparent, of course, that the sequence is not critical, and that the steps could be reversed. It is only important that the appropriate region receive proper treatment in accordance with an appropriate design rule. All of the above processes can be performed in software with a conventional computer system as noted earlier that is adapted to execute the types of code described herein. Moreover, the aforementioned software routines/programs may be implemented using any number of well-known computer languages known to those skilled in the art in this area, and thus the invention is not limited in this regard. [0037] Accordingly, the invention ensures that all types of memory regions have to fulfill all memory rules of their group. Correspondingly, all logic regions have to fulfill logic and memory rules (all logic regions that passed logic rules should have also passed memory rules since memory rules are looser compare to logic rules). The process is superior to prior art techniques in that it avoids false errors, and is more reliable, more efficient, etc. [0038] Thus, as noted FIG. 4, Mask Pattern Data 430 is fed into design rule checker 440 to check against both the logic and different memory rules as such may be needed. It is understood, of course, that in the case where an IC does not require mixed types of circuit types (i.e., logic and memory) that it may not be necessary to run both types of checks on each layer. The output of this process is a design rule check result file 450 . The results consist of only real logic 451 and real memory errors 452 . Thus, the present method divides layers of a mask pattern data into LOGIC, BDSP, BLSP; DP and ROM regions (or as many regions as there are different circuit types) so that the right sets of rules will only apply to the right regions. In this manner, false design rules are eliminated, and the implementation of circuit designs into silicon form is expedited as well. [0039] Although the present invention has been described in terms of a preferred embodiment, it will be apparent to those skilled in the art that many alterations and modifications may be made to such embodiments without departing from the teachings of the present invention. In addition, many other industries, including liquid crystal display manufacturing and similar micro-patterned technologies, may benefit from the teachings herein. Accordingly, it is intended that the all such alterations and modifications be included within the scope and spirit of the invention as defined by the following claims.

An improved system and method is disclosed for performing a design rule check on a proposed integrated circuit (IC) layout, and for creating customized design rule check command files. The individual layers of the IC (a system on chip—SOC) are separated into different regions having different kinds of features (i.e., memory or logic). Each different type of region is then analyzed in accordance with the customized design rule command file so that so-called “false errors” are eliminated. The invention thus improves, among other things, a development time for getting a design implemented in silicon.

big_patent

This invention was made with Government support under contract F300606-88-D-0025 awarded by Rome Air Development Center, Department of the Air Force. The Government has certain rights in this invention. This application is a continuation-in-part of U.S. Patent application Ser. No. 07/790,516 filed Nov. 12, 1991 now abandoned. The entire disclosure of the parent application is incorporated herein by reference FIELD OF THE INVENTION This invention pertains to the use of waveguide holograms for use as illuminators of objects having specific illumination requirements. In particular, objects having special illumination requirements, such as display holograms or spatial light modulators can be illuminated with waveguide holograms as disclosed herein. BACKGROUND OF THE PRIOR INVENTION In applicants parent application Ser. No. 07/790,516, waveguide holograms are disclosed, based on the use of thin substrate waveguides. These waveguides are characterized by the relationship between the width w of an incident laser beam coupled onto an optical waveguide having a thickness t. This relationship is controlled by λ, where λ is the wavelength of the incident lightwave. Thin substrate waveguides are characterized by t>>λ, In this situation, one can avoid difficulties encountered in coupling the optical source to the thin film waveguide, and allow for convenient white light illumination. At the same time, t<w, so that the illumination obtained is uniform. The inventors have now discovered that these thin substrate waveguides can be particularly used for situations requiring controlled illumination. There are a wide variety of situations which require illumination of an object in an controlled fashion. This is particularly the case where one seeks to illuminate a spatial light modulator (SLM) or hologram. Certain requirements present major difficulties for conventional illumination systems. Initially, illustrating with traditional illumination of a transmissive object (FIG. 1a) and a reflective object (FIG. 1b), conventional illuminators require a substantial amount of space to perform the transformation from the wavefront emitted by the light source to the one required on the object. This space usually contains several optical elements which are the origin for stability problems, alignment difficulties and obstruction of other light beams that may be required in the optical system. Second, for some illumination, it is desired not to flood the object to be illuminated with light. Rather, the illuminator seeks to pattern the light so it hits only in preselected areas. This can increase illuminator efficiency if the light is redirected, instead of simply being partially blocked. Additionally, if the light source is broad band, spectral filtering may be required. As one example of such a situation, illumination of holograms presents particular problems. Some may have their own built-in spectral filters, while others permit white light illumination. If incoherent light sources used, the filter provides the needed amount of spatial coherence, while if lasers are employed, the filter is required to clean up the coherent noise. Accordingly, it remains an object of those of skill in the art to provide a method for selectively illuminating demanding objects, such as holograms and spatial light modulators. SUMMARY OF THE INVENTION Applicants have discovered that thin substrate waveguides can be used to provide improved, controlled illumination of objects, including holograms and spatial light modulators. The illumination system can comprise a thin substrate waveguide optically coupled to a coherent light source, such as a laser. This illumination system provides extremely high diffraction efficiencies. Non-uniformity of the diffracted wavefront in the direction of propagation can be compensated for by exposing a photographic emulsion to the beam without compensation. The photographic negative absorbs most where the beam is brightest, and therefore, upon subsequent illumination through the negative, the wavefront passing is uniform. In an alternative approach, the hologram of the waveguide hologram illuminator can be recorded non-uniformly, so that the reconstructed beam formed is uniform in intensity. Both corrections can be employed. BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1a and 1b are illustrations of prior art illumination systems for transmissive and reflective objects respectively. FIG. 2(a) and 2(b) are illustrations is an illustration of a thin substrate waveguide optically coupled to a light source. FIG. 3 is an illustration of the volume occupied by conventional lens systems, FIG. 4 is an illustration of repetitive diffraction of light out of a waveguide in the direction of propagation. FIGS. 5 and 6 are schematic representations of recording systems used to record a waveguide hologram grating to prepare the illuminator of the claimed invention. DETAILED DESCRIPTION OF THE INVENTION This invention may be better understood by the following discussions, with reference to the Figures presented. The illumination system claimed herein is based on the waveguide hologram of the parent application incorporated herein. Thus, in essence, the illumination system comprises a light source which is optically coupled to a waveguide, on a surface of which is formed a hologram, which can be displayed or used to illuminate, selectively, the object of interest. Herein, waveguide holograms are referred to as WGH. WGHs are normally flat and can be optically contacted to the objects they illuminate as indicated by the diagrams of FIG. 2. Thus the relatively complicated systems of FIG. 1 are replaced by compact, rugged arrangements. Mutual alignment is easily maintained and reflection losses at the air-glass interfaces are readily reduced by index matching oil or optical cement. Comparing with a conventional lens illumination system, the WGH illuminator occupies much less space. Shown in FIG. 3, a conventional lens illumination system occupies a volume approximately ##EQU1## wherein f is the focal length of the main lens, A is the numerical aperture, and M is the magnification of the collimator. In the Figure, L1 is the focusing lens, L2 is the main lens, and O is the object to be illuminated. For reflective spatial light modulators or SLMs, the volume for the illuminators increases to ##EQU2## On the other hand, the active volume for a WGH illuminator is no more than ##EQU3## where is the thickness of the waveguide substrate. Usually h<<f. Taking the ratio of V rl to V wi , we obtain the gain of a WGH illuminator as ##EQU4## The diffraction efficiency, n, is the fraction of the light from the illuminating source which is diffracted into the required beam. For conventional display holograms, n=0.6 is sometimes obtained and for holograms made by two plane waves n=0.99 is attainable. WGH illuminators can, in principle, also achieve very high diffraction efficiency (of order approaching 0.99), however, high efficiencies over large area holograms requires very careful design as will be discussed below. For purposes (minimizing noise, making viewers comfortable, etc.) what is more important than just the efficiency is the absence of stray light propagating forward the observer. From this point of view WGHs are ideal. The undiffracted light from a WGH illuminator never enters the instrumentation or the eye of the viewer due to the total internal reflection at the waveguide surfaces. Let the diffracted light have irradiance Hd and the undiffracted light leaving the hologram be H u . Then ##EQU5## for display holograms can approach 0.25. For holographic recording of two plane waves, E can approach 0.99, while for all types of WGH E≧0.999 is routinely achievable since the undiffracted light is trapped in the waveguide. Along with the advantages of WGHs as illuminators, there are some penalties that must be paid. With a laser illuminated single-mode waveguide hologram, alignment of the laser beam is critical. This can lead to certain lack of ruggedness. Because light enters one side of the waveguide hologram and travels to the other, there is a time delay across the hologram. If we try to use a waveguide hologram for clock distribution, this builds in a clock skew. If we use the waveguide hologram as a way to produce spatially-coherent illumination beam, we must be sure that the temporal coherence time of the source exceeds this time delay. Another way of saying this is that source temporal coherence manifests itself as spatial coherence in a waveguide hologram illuminator. In addition, nonuniformity of the diffracted wavefront along the propagation direction is inevitable unless combated. Light diffracted out of the waveguide at one point is simply not available for diffraction at a later point. This aspect of the WGH illumination process is shown in FIG. 4. Assume the guided illumination beam is collimated. When it reaches the area where a hologram is placed, the beam encounters the region 1 of the hologram first. Part of light is diffracted as the reconstruction of the image, and the rest of light reflected. After the total internal reflection at the other waveguide surface, the residual light illuminates the region 2 on the hologram and undergoes the second reconstruction. This process repeats until the illumination beam passes the hologram area. Because WGHs have this unusual reconstructive mechanism, it is necessary to distinguish two different types of diffraction efficiencies. Assume the initial intensity of the illumination beam in FIG. 4 is I o , and the intensities of diffracted light from region 1,2 . . . , N are I 1 , I 2 , . . . , I n respectively. then the global diffraction efficiency of the WGH is defined as ##EQU6## On the other hand, the local diffraction efficiency in the region i is defined as: ##EQU7## where I io is the intensity of the illumination beam immediately before entering the hologram region i. For conventional holograms, the global and the local diffraction efficiencies are equal because N=1. If the hologram is recorded uniformly, that is n L1 =n L2 = . . . =N Li = . . . =n LN =N, then I.sub.ι =I.sub.0 η(1-η).sup.ι-1 Substitute Eq. 8 to Eq. 6, the global efficiency is expressed as: η.sub.G =1-(1-η).sup.N. by plotting I i , vs. i as shown in FIG. 4, we see that the holographic image is not reconstructed uniformly if all the local efficiencies are the same,i.e., the hologram is recorded uniformly. This problem may be called illumination depletion. Moreover, a WGH tends to produce two diffracted beams, one out of each side. For display holograms, this can be an advantage. However, for illuminator holograms, it is not easy to use both beams and the unutilized beam reduces the useful efficiency and may introduce noise into the system. Additionally, if light enters the waveguide by diffraction at some angle to the waveguide and exits via the hologram at any angle other than the angle or its opposite, light dispersion results. Thus, an input of white light results in a spectral output. This can be redressed by providing an input grating or hologram diffractor with an output direction equal or opposite to the angle of the hologram output. Both diffraction events are dispersive, but collectively they cancel. Aligning sensitivity can be combatted in two ways. First, we can attached the source, such as a diode laser, firmly to the edge of the waveguide or to the input of an input coupler or to an optical fiber which is itself firmly attached to the optical input couplers. Second, we can use a spatially and spectrally broad source and allow the waveguide to select out the portion of the available light which is properly matched to it. A WGH can achieve high spectral selectivity about 2-5 Å due to its double selection by the hologram and the waveguide. Compensating for illumination depletion can be done a priori or a posteriori. A posteriori compensation is very light inefficient. Basically, we may expose a photographic emulsion to the uncompensated beam. A photographic negative of that pattern absorbs most where the beam is brightest and, therefore, uniformizes the wavefront passing through it. The a priori approach records the hologram nonuniformly so that the reconstructed beam is uniform. To derive an appropriate nonuniform beam to record, we illuminate uniformly through the photographic negative just described. For extremely high uniformity, we might follow a priori compensation with a posteriori compensation which can now be highly efficient because it is making only small corrections. The problem of two-sidedness has a variety of potential solutions. We can absorb the light emerging from one side by an absorbing paint applied carefully not to damage the waveguide property of the guide. The other side will still be useful for transillumination. We can also place a mirror on one side to reflect all of the light into the same direction. Another solution is using off-axis illumination leading to an off-axis secondary beam keeping it from entering the illuminated optical system. If we are illuminating SLMs, new possibilities arise. We can diffract out only polarized light and use the SLM to modulate the polarization. We can then use polarization analyzers to control or block the unmodulated light. With very precise reflective systems, using phase modulation, we can cause selective constructive and destructive interference between the directly emitted beam and the reflected beam. Two basic architectures were used in our experiments to record the WGH grating. The first configuration is a modified conventional holographic recording system (FIG. 5). A cubic glass prism, CP, is employed to create a reference beam with very steep incidence angle. The recording plate, R, is optically contacted with CP by index matching. The second configuration (FIG. 6) is suitable for the waveguides with more stringent requirements. In this configuration the reference beam is coupled into the waveguide by a prism coupler, PC, and can be exactly reproduced for reconstruction. All holograms discussed in this communication were recorded on silver halide plates (Agfa 8E75) and bleached. The recording medium was optically contacted to a thin substrate glass waveguide with index matching oil. A SLM was illuminated by a white light illuminator which was recorded using the system of FIG. 5. In these experiments a plastic fiber ribbon was used to couple the light from a remote source indicating the convenience and flexibility of such illuminators. The color of the diffracted illuminating light depends, in this configuration, on the viewing angle. However, if a diffuser is placed between the SLM and the WGH, the colors are angularly mixed to reproduce the white illumination of the source at all angles. Illuminating the hologram by coherent laser light generated a coherent illumination beam suitable for reconstructing a 3-D holographic image. The quality of the reconstructed beams was analyzed from various points of view qualitatively and also quantitatively. Particular emphasis was placed on polarization and phase characteristics. A slight nonuniform depolarization was observed by using an imaging polarimeter. The origin of this depolarization and its nonuniformity is probably in some local strains and is still under investigation. When a hologram recorded by the configuration of FIG. 5 is illuminated by a coherent wave, the wavefront is distorted by an essentially random phase distribution. To reconstruct a cleaner wavefront, the configuration of FIG. 6 must be employed. In our experiments about 10% of the light in the source was diffracted out into the +1 diffraction order with about 2% in the -1 (the other side of the waveguide). About 30% of the light was coupled out of the edge, scattered and absorbed. The remaining 58% was lost due to inefficient coupling. The invention described above has been disclosed with reference to generic description and specific embodiments. Save for the limitations presented in the claims below, the examples set forth are not intended to be, and shall not be construed as, limiting in any way. In particular, selection of other light sources, objects for illumination and the like will occur to those of ordinary skill in the art without the exercise of inventive skill, and remain within the scope of the invention as claimed hereinbelow.

A waveguide hologram illumination system is based on thin substrate waveguides bearing a hologram on the surface through which light is diffracted out. A light source is optically coupled to the waveguide such that light emitted from the source is caused to propagate along the waveguide, being diffracted out at intersections with the surface of the waveguide on which the hologram is formed. The selective emission through the hologram can be advantageously used to illuminate display holograms or spatial light modulators. Provisions are made for rendering the amount of light emitted through the hologram uniform along the length of the hologram.

big_patent

This is a division, of application Ser. No. 860,240, filed May 6, 1986, now U.S. Pat. No. 4,801,877. FIELD OF THE INVENTION This invention relates generally to the field of testing rotors of dynamoelectric machines, such as electric motors and generators, and more particularly to a method and apparatus for testing squirrel cage rotors for induction motors to obtain the resistance, reactance, and effective electrical skew of the rotor to permit identification of rotor defects. BACKGROUND OF THE INVENTION Squirrel cage rotors for modern induction motors typically include a core comprised of a stack of steel laminations and an aluminum squirrel cage conductor arrangement, usually formed as a die casting. Manufacturing techniques have been perfected to the point where these rotors are mass produced with a high probability of uniformity and high quality. There are, however, a number of possibilities for deficiencies, including porosity or impurities in the aluminum casting and open circuits in the squirrel cage conducting bars which can affect the electrical resistance of the rotor, poor insulation between the squirrel cage conductors and the iron core which can produce undesired variations in the effective skew, and various other manufacturing defects. Thus it is desirable to test dynamoelectric machine rotors economically and reliably to detect such defects. Because quality problems are generally infrequent, it is not economical to perform expensive tests on every individual rotor. However, since hidden defects do occur, in order to maintain a high degree of quality control there is a need to perform low cost tests on each rotor before it is assembled with a stator to form a complete machine. Further, it can be desirable to obtain information on the resistance, reactance and effective skew of the rotors for evaluation of defects, manufacturing processes and quality control. A number of prior art methods have been developed in an attempt to test squirrel cage rotors. Some, such as that disclosed in U.S. Pat. No. 2,844,794, assigned to the assignee of the present invention, require the use of the dynamoelectric machine stator core, while others use destructive testing techniques. One non-destructive prior art technique for testing rotors independent of the stator is disclosed in U.S. Pat. No. 3,861,025, assigned to the assignee of the present invention. This technique involves rotating the rotor in a static magnetic field and evaluating the waveform of the resulting induced voltages displayed on an oscilloscope. This technique requires extensive operator training to interpret the oscilloscope display, and has inherent limitations on the results that can be achieved. Another prior art testing technique utilizes a stator fixture excited by a fixed AC current into which the rotor is placed and manually rotated to obtain a peak power measurement (i.e. power into the rotor) using a pick-up coil. By using the current measurement, the impedance of the rotor can be obtained, but separate resistance, reactance and skew information can not be determined. It is accordingly an object of the present invention to provide a novel and improved method and apparatus for non-destructive testing of dynamoelectric machine rotors. It is another object of the invention to provide a novel, economical, and reliable method and apparatus for non-destructive measurement of the resistance and reactance of dynamoelectric machine rotors. It is yet another object of the invention to provide a novel, economical and reliable method and apparatus for non-destructive measurement of the effective skew of dynamoelectric machine rotors. It is yet another object of the invention to provide a novel, economical, and reliable method and apparatus for non-destructive testing of dynamoelectric machine rotors which provides automatic pass/fail determinations. It is still another object of the invention to provide a novel, economical, and reliable method and apparatus for non-destructive testing of dynamoelectric machine rotors including the measurement of resistance, reactance and skew and a detailed statistical comparison and evaluation of the measurement results, as well as automatic identification of defective rotors. SUMMARY OF THE INVENTION Briefly, according to preferred embodiments of the invention, a test apparatus and method is provided for testing dynamoelectric machine rotors. The apparatus comprises a test head for accepting and causing relative angular movement between the rotor and test head and includes exciting means for magnetizing the rotor during such angular movement in response to an alternating current. Voltage sensing means is provided for generating a voltage signal responsive to the magnetic flux variations generated by the rotor in response to the magnetization by the exciting means. Current sensing means is provided for sensing the magnitude of the alternating current utilized to magnetize the rotor and for generating a current signal representative thereof. Processing means is provided for determining the resistance and reactance of the rotor responsive to the voltage signal and current signal. In addition skew sensing means may be provided for sensing the effective electrical skew of the rotor and for generating an effective skew signal responsive thereto. The processing means is usable for determining an effective electrical skew of the rotor responsive to the effective skew signal. The subject matter of the invention is particularly pointed out and distinctly claimed in the claims at the concluding portion of this specification. The invention itself, both as to its organization and method of operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagrammatic front view illustrating a specific embodiment of a dynamoelectric machine rotor test apparatus for testing squirrel cage rotors in accordance with the invention. FIG. 2 is a cut-away perspective view illustrating a specific embodiment of a typical squirrel cage rotor. FIG. 3 is a detailed block diagram illustrating a specific embodiment of the dynamoelectric machine rotor test apparatus for testing squirrel cage rotors in accordance with the invention. FIG. 4 is a cut-away perspective view illustrating the core configuration of a specific embodiment of the test head of the test apparatus illustrated in FIG. 3. FIG. 5 is a cut-away diagrammatic view illustrating the structure of a specific embodiment of the test head of test apparatus illustrated in FIG. 3. FIG. 6 is a cross sectional view illustrating the skew winding portion of a specific embodiment of the test head of the test apparatus illustrated in FIG. 3. FIG. 7 is a diagrammatic view illustrating the structure of a specific embodiment of the test head of the test apparatus illustrated in FIG. 3. FIG. 8 is a diagrammatic view illustrating a laid open structure of a specific embodiment of the test head of the test apparatus illustrated in FIG. 3. FIG. 9 is a diagrammatic view illustrating a specific embodiment of the test fixture structure of the test apparatus illustrated in FIG. 1 with the test fixture in the rotor extended position. FIG. 10 is a diagrammatic view illustrating a specific embodiment of the test head and mechanical structure of the test apparatus illustrated in FIG. 1 with the test head in the rotor retracted position. FIG. 11 is an expanded diagrammatic view illustrating a specific embodiment of the test head and rotor clutch mechanism illustrated in FIG. 9 in the rotor extended position. FIG. 12 is an expanded view of a portion of the rotor clutch mechanism illustrated in FIG. 11. FIG. 13 is an expanded diagrammatic view illustrating a specific embodiment of the test head and rotor clutch mechanism illustrated in FIG. 10 in the rotor retracted position. FIG. 14 is an expanded view of a portion of the rotor clutch mechanism illustrated in FIG. 13. FIG. 15A is a flow diagram illustrating the program flow for one embodiment of the data processor of FIG. 3. FIG. 15B is a flow diagram illustrating the program flow for one embodiment of the control processor of FIG. 3B. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a general diagrammatic front view illustrating a preferred embodiment of the dynamoelectric machine rotor test apparatus 20 according to the invention. The test apparatus 20 is a dual test fixture embodiment having two test fixtures 22, 24. Other embodiments utilizing one fixture or more than two fixtures will be apparent to those skilled in the art in view of the disclosure provided hereinafter. The two test fixtures 22, 24 each respectively comprise a test head 26, 28 and a hydraulically driven retraction and drive mechanism 36, 38. The retraction and drive mechanism 36, 38 functions to retract and rotate the rotor within the test head in response to activation of a start button 32, 34 associated with the respective test fixtures 22, 24. The test fixtures 22, 24 are mounted, as shown, in a test stand 30 to provide convenient access by an operator. Each test fixture 22, 24 is coupled to a data acquisition, processing and control system 40 mounted in a rack 42 as shown. The system 40 comprises data acquisition and processing circuitry in a drawer 51, coupled to a terminal 44, and to a printer (e.g., an Epson RX-80) contained in a drawer 53, and coupled to a power supply 54. The terminal 44 comprises a display 46 (e.g., a Computerwise, Inc., Transterm Model TM-71 LCD Display) for displaying test results, control information, and other data, and a keyboard 48, (e.g., a Computerwise, Inc. Transterm Model TM-71 16-key, alpha/numeric keyboard) for entry of data and control information. The printer permits the printing of results and other data, while the power supply 54 provides electrical power for all of the electrical elements of the apparatus 20. The single common data acquisition, processing and control system 40 controls testing and acquires data from each test head 22, 24 independently. In response to initiation of a test on a respective fixture 22, 24 by a operator, the system 40 automatically performs the rotor test on the respective test fixture. Thus, once the test sequence is initiated by the operator, the system 40 controls the rotation of the rotor within the fixture, the acquisition of data via the fixture, and the processing of the acquired data without further operator intervention. A typical squirrel cage rotor suitable for testing by the apparatus 20 is illustrated in FIG. 2. The rotor 60 includes a cylindrical core 62 formed of a stack of laminations made of a magnetic material such as iron. The rotor core 62 includes a center opening 65 which runs axially through the center of the rotor 60 and which is intended to be mounted on the rotor shaft (not shown). The rotor core 62 also includes a circumferential series of nearly axial slots 64 near the outer diameter of the rotor 60. These slots may be disposed in a skewed or inclined relationship with respect to the longitudinal axis of the rotor. The squirrel cage windings are provided by an aluminum casting 66 disposed in and about the rotor core 62 comprising conductive bars 67 which fill the slots 64 and conductive end rings 68, 69 integral with the conductive bars. This structure will have inherent resistance and reactance characteristics which are highly dependent on the proper construction of the rotor such as proper formation of the conductive bars in the slots 64. In addition, the skew characteristics of the rotor are largely determined by the angle of incline (i.e. skew) of the conductive bars off of the true longitudinal axis. However, variations of the properties of the magnetic material, the aluminum casting, the iron to aluminum insulation, etc. will produce variations in the effective electrical skew (i.e., the skew as measured by its effects on the electromagnetic field in the air gap). The test heads 26, 28 of the test fixtures 22, 24 have a unique construction which may best be understood by reference to FIGS. 4-8. The test heads 26, 28 comprise a structure utilizing a core of magnetic material 200 very similar to a conventional dynamoelectric machine stator as illustrated in FIG. 4. This core is formed in the conventional manner of a stack of laminations of magnetic material such as iron, shaped to provide a plurality of slots which permit a set of windings to be arranged in the slots as illustrated in FIG. 5. FIG. 5 is a diagrammatic illustration of the structure of a test head 26 (also see FIG. 7). The test head includes a set of primary windings 210 which form at least one pair of poles 212, 214 as illustrated in FIG. 7. These primary windings form the exciting current carrying winding for the test head 26 which, when an alternating current is supplied during a rotor test, creates an alternating magnetic field in a center cylindrical cavity 220. For testing, the rotor is positioned within the center cavity 220 and rotated, thereby inducing voltages in the rotor. This results in induced currents in the rotor and consequently generation of magnetic flux by the rotor which is sensed by the pick-up coil 106. The pick-up coil 106 comprise a set of coil windings in which is generated a voltage representative of the voltage induced in the rotor. These coils are, in the illustrated embodiment, composed of a multiple turn loop (any number of turns may be used), as shown, coupled in series to provide the voltage signal. In the preferred embodiment, these voltage pick-up coils 106 are wound over the primary coils 102. The test head 26 also includes a skew pick-up coil 110 located at one end of the test head structure 26. This skew pick-up coil 110 is positioned in quadrature with the poles 212, 214 and at the end of the core 200 to sense flux build-up at the end of the rotor due to the skew characteristics of the rotor. In the illustrated embodiment, the skew pick-up is composed of two multiple turn loops coupled in series, as shown, although other coupling configurations and any number of turns (N) may be used. The skew pick-up coils 110, in the illustrated embodiment, are positioned within a groove 222 near the end of the core 200, as may best be understood by reference to FIG. 6. For a further understanding of the structure of the coils of the test head 26, reference may be made to FIG. 8 which shows a diagrammatic view of the test head 26 laid flat. The primary windings 102 are shown forming two poles 212, 214 with the voltage pick-up coils 106 wound in some of the slots among the primary coil windings 102. The skew pick-up coil 110 is shown in quadrature relationship to the primary windings at one end of the core 200. Referring now to FIG. 3, there is shown a detailed block diagram illustrating a specific embodiment of the dynamoelectric machine rotor test apparatus 20. Each test head 26, 28 includes an excitation means 102, 104 composed of the set of current carrying windings which produce an alternating magnetic field when energized by an alternating current of predetermined magnitude (e.g., 60 hz at 2.4 amps in the illustrated embodiment) coupled from the power supply 54, as shown. The magnetic field produced will magnetize a rotor rotated within the field producing magnetic flux which is dependent upon the rotor characteristics. Each head 26, 28 also includes the voltage sensing pick-up coil 106, 108 responsive to the rotor induced magnetic flux which produces a voltage signal representative of the voltage induced in the rotor. The skew sensing pick-up coil 110, 112 is also located in the test head 26, 28 which produces an effective skew signal responsive to flux build-up at the end of the rotor due to the rotor's effective skew. Each of these sense signals is coupled to a sample and hold circuit 120, as shown (e.g., a Burr-Brown ADSHC-85). A current sensor 114 (e.g., a conventional current transformer), coupled as shown to the supply 54, senses the current provided to energize the test heads 26, 28 and couples a current sense signal to the sample and hold circuit 120. Also coupled to the power supply 54 is a phase lock loop 122 (e.g., a National CD4046) which generates timing pulses which are phase locked to the exciting alternating current supplied to the test head windings 102, 104. In the illustrated embodiment, there are 32 pulses generated for each cycle of the exciting alternating current such that each pulse is generated at the same phase of the cycle for each succeeding cycle. These phase locked timing pulses are coupled, as shown, to the sample and hold circuit 120 to synchronize the sampling of the sense signals coupled from the voltage pick-up 106, the skew pick-up 110, and the current sensor 114. The phase locked timing signals are also coupled to a data processor 140 via a conductor 127, as shown. The sample and hold circuit 120 and the phase locked loop circuit 122 are part of an analog to digital system 130 which also includes an analog multiplexor 124 (e.g., an Analog Devices AD7506) and an analog to digital converter 126 (e.g., Analog Devices ADC1131 high speed, 14 bit converter) configured as shown. The analog to digital system 130 is a subsystem of the data acquisition and processing circuit 50. The data acquisition and processing circuit 50 controls the acquisition of the test data and processes the data to produce useful test results as well as rotor pass/fail determinations. The data acquisition and processing circuit 50 also includes the data processor to 140 (e.g., an Intel 86/14 microcomputer) and a control processor 150 (e.g., an Intel 86/35 microcomputer) as shown. This multi-computer system provides highly efficient data acquisition and processing, although other configurations (e.g., a single microcomputer system) may also be used. During a rotor test, the sample and hold circuit 120 simultaneously samples each of the sense signals each time a timing pulse from the phase locked loop 122 occurs. Simultaneous sampling of current and voltage sense signals permits calculation of a power value (W) (note: simultaneous sampling of the skew signal is not needed to permit the calculation of a power value). These samples, taken by the sample and hold circuit 120 are coupled to an analog multiplexer circuit 124, as shown. The analog multiplexer 124 multiplexes the samples sequentially, under the control of the data processor 140, to an analog to digital converter 126. The analog to digital converter digitizes the samples and couples the digitized samples to the data processor 140. The digitized samples coupled to the data processor 140 are processed to reduce the data to usable form. In the illustrated embodiment, the processor 140 acquires 32 samples in a cycle of the exciting alternating current (i.e., at 60 hz, one sample every 520 microseconds), then ignores samples for the next five cycles, and samples again for 32 samples. (The flow of program control for the processor 140 may be more fully understood by reference to the flow chart 260 illustrated in FIG. 15A in conjunction with the following description). This pattern is continued for a total of forty sampling cycles of 32 samples each to complete one rotor test sampling sequence in four seconds. Once the data is acquired for each sample cycle, the processor 140 multiplies each current sample by the corresponding voltage sample to obtain a power value W (where W is power into the rotor). The 32 samples of the voltage signal, current signal, skew signal, and power value are then processed to obtain four test values which are a mean power value (W), and a root means square (rms) value for the voltage (V), current (I), and skew (SK) signals. This process is repeated 40 times, once for each sample cycle, thereby obtaining 40 sets of the four test values. These forty sets of test values are coupled from the data processor 140 to the control processor 150 at the end of a rotor test sequence. (The flow of program control for the control processor 150 may be more fully understood by reference to the flow chart 270 illustrated in FIG. 15B in conjunction with the following description). The control processor 150 then determines a mean resistance (R), reactance (X), and effective skew (ESK) for the rotor from the 40 test values, as well as the range of the 40 values for the resistance (referred to as dissymmetry, DS) and the effective skew (referred to as skew dissymmetry, DSK). Each resistance value (R) is determined by the formula R=W/I.sup.2. Each reactance value is determined by the formula X=((VI).sup.2 -W.sup.2)1/2)/I.sup.2. The effective skew is determined by the formula ESK=SK/(I.sup.2 ×N) where N=the number of turns of the skew pick-up coil. Once the resistance, reactance, and effective skew values have been determined, the data is scanned to determine the maximum and minimum resistance and effective skew values. In addition, an average value of resistance, reactance, and effective skew is determined by summing the forty values for each and dividing by forty. These values are stored in internal memory within the data processor 140. After all of the values have been calculated, the average value for resistance, reactance, and effective skew are each compared to predetermined maximum and minimum threshold values. In addition, the dissymmetry value is compared to a predetermined maximum. The maximum and minimum values may be entered through the key board 48 by the operator prior to the beginning of a test run. If the calculated values for the rotor are within the predetermined maximum and minimum threshold value, then the rotor is passed as a good rotor. However, if the rotor has any value outside of the predetermined limits, a fail (reject) indication is provided to the operator by means of an indicator such as a light or audible signal (not shown) to indicate a defective rotor. The reject signals to activate the fail indicators are generated on outputs 162 and 164, as shown. In addition to the calculated values, additional statistical information is also determined and stored on a Winchester magnetic disk 55 coupled to the control processor 150, as shown. Among the types of data stored on the Winchester disk 55 are totals of the number of passed rotors, the number of fail rotors including how many failed for each threshold, running sums of each of the calculated values, and running sums of the squares of each of the values. This data permits the determination of statistical information over numerous tests of a test run, including such information as averages and standard deviation. All the calculated values of resistance, reactance, effective skew, dissymmetry, and skew dissymmetry for each test are displayed on the display 46 at the end of a test. In addition, the printer 52 may be used to print the results of a test as well as the statistical data. The printer 52 is activated by the operator via commands from the keyboard 48. The control processor 150 also controls the sequence of events that occur during a test. Various input and output signals are coupled between the control processor 150 and an opto-isolator 160 (e.g., an opto-22) via a bus 166, as shown. The opto-isolator provides a control interface to the test fixtures 22, 24. The start switches 32, 34 are coupled to the opto-isolator 160 which couples the start signal to the processor in response to activation of one (i.e., Right (R) or Left (L)) of the start switches 32, 34. In response, the control processor 150 couples a control signal through the opto-isolator 160 to the appropriate retraction and drive mechanism 36, 38 (described in greater detail hereinafter with reference to FIGS. 9-14) which activates the mechanism 36, 38 thereby starting the rotor test. The retraction and drive mechanism 36, 38, in response to activation, retracts a rotor placed on a test head 26, 28. When the rotor is fully retracted such that it is in place for testing, a position sensor 170, 172 (e.g., a conventional limit switch) generates a position signal which is coupled through the opto-isolator 160 to the control processor 150 via conductors 174, 176. In response to the position signal, the control processor 150 generates a drive signal which is coupled through the opto-isolator 160 to the drive motors 180, 182 via the conductors 184, 186. This drive signal activates the motor 180, 182 to rotate the rotor. In the illustrated embodiment, the rotor is rotated at a rate of 1 revolution in four seconds, and is rotated one full rotation for a complete test sequence (i.e., rotation for four seconds). During the four second test sequence, the data acquisition and processing system 50 acquires the desired data after which three seconds are utilized for the data to be processed. The use of the two fixture system permits the operator to set up a rotor on the unused fixture during this seven second test sequence. Thus, the dual fixture system allows more efficient testing by reducing delays due to the operator set up time. It also increases the cost effectiveness of the apparatus because both fixtures can be controlled with a single processing system. During operation, a test is initiated by an operator by placing a rotor to be tested onto the test head, for example, head 26. The operator then initiates the test sequence by activating the start button 32, which signals the control processor 150 to activate the retraction mechanism thereby retracting the rotor to the test position. Once fully retracted the position sensor 170 generates a signal coupled to the control processor 150 which causes the control processor 150 to generate the motor activation signal, which activates the motor 180 to rotate the rotor. The rotor is rotated at a rate of one rotation in four seconds, and one complete test sequence is completed in one rotation. During the four second rotation period the voltage sensor 106, skew sensor 110, and current sensor 114 are sampled by the sample and hold circuit 120. The sample and hold circuit 120 is timed synchronously with the exciting alternating current applied to the coils 102 by timing signals from the phase lock loop circuit 122. During this test sequence, 32 samples are taken during one cycle of the alternating current exciting signal, and one set of samples are taken every sixth cycle producing a total of forty sets of data. This data is coupled to the data processor 140 which does the initial processing of the data and couples the results to the control processor 150. The control processor 150 then performs the final processing, calculating resistance, reactance, skew, dissymmetry and skew dissymmetry. These values are displayed on the display 46 and may be printed on the printer 52 in response to commands entered through the keyboard 58. Information to permit statistical analysis over a series of tests is then stored on a Winchester disk 55. Referring now to FIG. 9, there is shown a detailed diagrammatic view illustrating a specific embodiment of the test fixture structure 22 on which a rotor 60 has been placed in the extended position. During operation, the rotor 60 is retracted to the test position as illustrated in FIG. 10. The test fixture 22 comprises the test head 26 and the retraction and drive mechanism 36. Located coaxially at the center of the center cavity 220 of the test head 26 is a spindle 230 over which the rotor 60 may be placed, as shown. The spindle 230 comprises a shaft 234 having an upper cylindrical cap 232 with a greater diameter than the shaft 234, and an annular ring 236 at the lower end through which the shaft 230 is slidably positioned, as shown. The annular ring 236 is mounted on a cylindrical mount 238 which is coupled by a spring loaded coupling to a shaft 240. The shaft 240 is slidably mounted in an aperture in the test stand 30 as shown. The shaft 230 is threadedly coupled to the shaft 240 and the shaft 240 is coupled to a drive motor 280 which rotates the rotor 60 when the motor is activated. This shaft-motor assembly is mounted on a bracket 242 which slidably engages a slide shaft 244. The bracket 242 is connected to a shaft 246 of a hydraulic cylinder 250 which is powered by an external source (not shown). In the extended position, the rotor 60 extends above the test head 26 when the entire retraction and drive mechanism 36 is in its upper-most position as shown in FIG. 9. When activated, the hydraulic cylinder 250 retracts the shaft 246 lowering the retraction and drive mechanism 36 to the position shown in FIG. 10. This lowers the rotor to the retracted position within the central cavity 220 of the test head 26. The rotor is then rotated by the drive motor 180 which is activated when a position sensor (see FIG. 3) detects that the mechanism 36 is in the retracted position. The rotor 60 is tightly held in position during rotation by a clutch mechanism more readily understood by reference to FIGS. 11-14. FIG. 11 is an expanded view of the top portion of the test fixture 22 in the extended position. The spindle 230, as illustrated in FIG. 11, comprises a set of annular sleeves 252 slidably positioned around a shaft 234, as shown. Between each sleeve 252 is an o-ring 254. These elements are held in place by the annular ring 236 and the cap 232. In the extended position, the o-rings are not compressed, and therefore do not extend in the radial direction beyond the edges of the annular sleeves 252, as illustrated in FIG. 12. Thus, the rotor 60 can easily slide over the spindle 230. However, when in the retracted position, as illustrated in FIG. 13, the annular ring 236 is pushed up against the annular sleeves 252 due to the movement of the shaft 234 downward. This compresses the o-rings 254 causing them to extend radially beyond the edge of the annular sleeves 252 contacting the inner surface of the rotor center cavity as illustrated by FIG. 14. As a result, the rotor 60 is securely held in place by the frictional force exerted on the rotor 60 by the extended o-rings 254. Thus, the rotor can be easily mounted on the spindle 230 when in the extended position but the rotor is securely held when in the retracted position. Preferred embodiments of the novel method and apparatus for testing dynamoelectric machine rotors have been described for the purpose of illustrating the manner in which the invention may be made and used. It should be understood, however, that implementation of other variations and modifications of the invention in its various aspects will be apparent to those skilled in the art, and that the invention is not limited by the specific embodiments described. It is therefore contemplated to cover any and all modifications, variations or equivalents that fall within the true spirit and scope of the basic underlying principles disclosed and claimed herein.

A method and apparatus for testing dynamoelectric machine rotors, particularly squirrel cage rotors for induction motors, to obtain resistance, reactance, and effective skew values to permit identification of rotor defects. The rotor is rotated in an alternating magnetic field and pick-up coils are used to sense the voltage generated in the rotor by sensing the magnetic flux generated by magnetization of the rotor during rotation. Current sensing is used to determine the current used in magnetizing the rotor and a separate skew pick-up coil is utilized to detect effective electrical skew. These signals are processed to determine whether the rotor meets predetermined pass/fail criteria, to provide detailed statistical data and to generate a failure indication responsive to one of the values falling outside respective predetermined limits.

big_patent

BACKGROUND [0001] As the computing power of mobile devices increase more sophisticated applications can be developed to utilize these resources. Typically a provider of such a mobile device may want to protect the device from attackers that try and obtain digital rights management keys or device keys. One way to secure the device is to ‘close’ the mobile device, e.g., manufacture the device in such a way as to only allow a certain type of hardware and proprietary closed source software. By closing the mobile device the provider can provide some level of security by making it more likely than not that only approved code and hardware is used in the device. [0002] While closing the mobile device may make it more difficult for an attacker to compromise the device, a provider may want to allow third parties to have some ability to develop applications. A provider may allow for some third party code to execute on a closed mobile device by providing a sandbox that verifies third party code at runtime, or by configuring the operating system of the device to segregate third party code from kernel mode code. While these techniques exist, there is a need for alternative techniques that can augment or supplement the typical security measures that require less computational power from the mobile device and enable the provider to have more control over how third party code is treated by the device. SUMMARY [0003] An embodiment of the present disclosure provides a method that includes, but is not limited to granting, to a managed library, access to native resources of an operating system in response to validating a digital certificate associated with the managed library; and denying, to a managed application, access to native resources of the operating system, wherein the managed application includes a digital certificate authorizing the managed application to access a specific native resource of the operating system through the managed library. In addition to the foregoing other method aspects are described in the detailed description, drawings, and claims that form the present disclosure. [0004] An embodiment of the present disclosure provides a method that includes, but is not limited to receiving, by a manager, a request from a managed application to access a native system resource through a managed library; authorizing, by the manager, the request to access the native system resource through the managed library, wherein the manager includes information that identifies managed libraries that the managed application is authorized to access, further wherein the manager is effectuated by native instructions; authorizing, by the manager, the request to access the native system resource by the managed library, wherein information that identifies that the managed library is authorized to access the native system resource was obtained from a digital certificate associated with the managed library; sending, by the managed library, a request to access the native system resource to a runtime host, wherein the runtime host is effectuated by native instructions; and accessing, by the runtime host, the native system resource. In addition to the foregoing other method aspects are described in the detailed description, drawings, and claims that form the present disclosure. [0005] An embodiment of the present disclosure provides a method that includes, but is not limited to receiving a package from a networked computer system; identifying an executable in the package; verifying managed metadata associated with the executable, wherein the managed metadata describes the structure of executable, further wherein verifying the managed metadata includes inspecting the managed metadata at runtime to determine that the executable includes type safe code; sending, by the managed library, a request to access the native system resource to a runtime host, wherein the runtime host is effectuated by native instructions; and accessing, by the runtime host, the native system resource. In addition to the foregoing other method aspects are described in the detailed description, drawings, and claims that form the present disclosure. [0006] It can be appreciated by one of skill in the art that one or more various aspects of the disclosure may include but are not limited to circuitry and/or programming for effecting the herein-referenced aspects of the present disclosure; the circuitry and/or programming can be virtually any combination of hardware, software, and/or firmware configured to effect the herein-referenced aspects depending upon the design choices of the system designer. [0007] The foregoing is a summary and thus contains, by necessity, simplifications, generalizations and omissions of detail. Those skilled in the art will appreciate that the summary is illustrative only and is not intended to be in any way limiting. BRIEF DESCRIPTION OF THE DRAWINGS [0008] FIG. 1 depicts exemplary general purpose computing system. [0009] FIG. 2 illustrates an example environment wherein aspects of the present disclosure can be implemented. [0010] FIG. 3 illustrates an example container. [0011] FIG. 4 it illustrates an example mobile device that can be used in embodiments of the present disclosure. [0012] FIG. 5 depicts an example arbitration layer that can be used to implement aspects of the present disclosure. [0013] FIG. 6 depicts an example operational procedure related to securing a computing device. [0014] FIG. 7 depicts an alternative embodiment of the operational procedure of FIG. 6 . [0015] FIG. 8 depicts an example operational procedure related to protecting a closed computing device from executing un-trusted instructions. [0016] FIG. 9 depicts an alternative embodiment of the operational procedure of FIG. 8 . [0017] FIG. 10 depicts an alternative embodiment of the operational procedure of FIG. 9 . [0018] FIG. 11 depicts an alternative embodiment of the operational procedure of FIG. 9 . [0019] FIG. 12 depicts an example operational procedure related to publishing videogames configured to execute on a mobile device. [0020] FIG. 13 depicts an alternative embodiment of the operational procedure of FIG. 12 . DETAILED DESCRIPTION [0021] Numerous embodiments of the present disclosure may execute on a computer. FIG. 1 and the following discussion is intended to provide a brief general description of a suitable computing environment in which the disclosure may be implemented. One skilled in the art can appreciate that the computer system of FIG. 1 can in some embodiments effectuate the validation system 212 , the community feedback server 206 , the electronic market place 222 , developer 204 , and peer reviewers 208 and 210 . One skilled in the art can also appreciate that the elements depicted by FIG. 2-5 can include circuitry configured to instantiate specific aspects of the present disclosure. For example, the term circuitry used through the disclosure can include specialized hardware components configured to perform function(s) implemented by firmware or switches. In other example embodiments the term circuitry can include a general purpose processing unit configured by software instructions that embody logic operable to perform function(s). In example embodiments where circuitry includes a combination of hardware and software, an implementer may write source code embodying logic that can be compiled into machine readable code and executed by a processor. Since one skilled in the art can appreciate that the state of the art has evolved to a point where there is little difference between hardware, software, or a combination of hardware/software and the selection of hardware versus software to effectuate specific functions is a design choice left to an implementer. More specifically, one of skill in the art can appreciate that a software process can be transformed into an equivalent hardware structure, and a hardware structure can itself be transformed into an equivalent software process. Thus, the selection of a hardware implementation versus a software implementation is one of design choice. [0022] Referring now to FIG. 1 , an exemplary general purpose computing system is depicted. The general purpose computing system can include a conventional computer 20 or the like, including a processing unit 21 , a system memory 22 , and a system bus 23 that couples various system components including the system memory to the processing unit 21 . The system bus 23 may be any of several types of bus structures including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures. The system memory includes read only memory (ROM) 24 and random access memory (RAM) 25 . A basic input/output system 26 (BIOS), containing the basic routines that help to transfer information between elements within the computer 20 , such as during start up, is stored in ROM 24 . The computer 20 may further include a hard disk drive 27 for reading from and writing to a hard disk, not shown, a magnetic disk drive 28 for reading from or writing to a removable magnetic disk 29 , and an optical disk drive 30 for reading from or writing to a removable optical disk 31 such as a CD ROM or other optical media. In some example embodiments computer executable instructions embodying aspects of the present disclosure may be stored in ROM 24 , hard disk (not shown), RAM 25 , removable magnetic disk 29 , optical disk 31 , and/or a cache of processing unit 21 . The hard disk drive 27 , magnetic disk drive 28 , and optical disk drive 30 are connected to the system bus 23 by a hard disk drive interface 32 , a magnetic disk drive interface 33 , and an optical drive interface 34 , respectively. The drives and their associated computer readable media provide non volatile storage of computer readable instructions, data structures, program modules and other data for the computer 20 . Although the exemplary environment described herein employs a hard disk, a removable magnetic disk 29 and a removable optical disk 31 , it should be appreciated by those skilled in the art that other types of computer readable media which can store data that is accessible by a computer, such as magnetic cassettes, flash memory cards, digital video disks, Bernoulli cartridges, random access memories (RAMs), read only memories (ROMs) and the like may also be used in the exemplary operating environment. [0023] A number of program modules may be stored on the hard disk, magnetic disk 29 , optical disk 31 , ROM 24 or RAM 25 , including an operating system 35 , one or more application programs 36 , other program modules 37 and program data 38 . A user may enter commands and information into the computer 20 through input devices such as a keyboard 40 and pointing device 42 . Other input devices (not shown) may include a microphone, joystick, game pad, satellite disk, scanner or the like. These and other input devices are often connected to the processing unit 21 through a serial port interface 46 that is coupled to the system bus, but may be connected by other interfaces, such as a parallel port, game port or universal serial bus (USB). A display 47 or other type of display device can also be connected to the system bus 23 via an interface, such as a video adapter 48 . In addition to the display 47 , computers typically include other peripheral output devices (not shown), such as speakers and printers. The exemplary system of FIG. 1 also includes a host adapter 55 , Small Computer System Interface (SCSI) bus 56 , and an external storage device 62 connected to the SCSI bus 56 . [0024] The computer 20 may operate in a networked environment using logical connections to one or more remote computers, such as a remote computer 49 . The remote computer 49 may be another computer, a server, a router, a network PC, a peer device or other common network node, and typically can include many or all of the elements described above relative to the computer 20 , although only a memory storage device 50 has been illustrated in FIG. 1 . The logical connections depicted in FIG. 1 can include a local area network (LAN) 51 and a wide area network (WAN) 52 . Such networking environments are commonplace in offices, enterprise wide computer networks, intranets and the Internet. [0025] When used in a LAN networking environment, the computer 20 can be connected to the LAN 51 through a network interface or adapter 53 . When used in a WAN networking environment, the computer 20 can typically include a modem 54 or other means for establishing communications over the wide area network 52 , such as the Internet. The modem 54 , which may be internal or external, can be connected to the system bus 23 via the serial port interface 46 . In a networked environment, program modules depicted relative to the computer 20 , or portions thereof, may be stored in the remote memory storage device. It will be appreciated that the network connections shown are exemplary and other means of establishing a communications link between the computers may be used. Moreover, while it is envisioned that numerous embodiments of the present disclosure are particularly well-suited for computerized systems, nothing in this document is intended to limit the disclosure to such embodiments. [0026] Referring now to FIG. 2 , it generally illustrates an example environment wherein aspects of the present disclosure can be implemented. One skilled in the art can appreciate that the example elements depicted by FIG. 2 provide an operational framework for describing the present disclosure. Accordingly, in some embodiments the physical layout of the environment may be different depending on different implementation schemes. Thus the example operational framework is to be treated as illustrative only and in no way limit the scope of the claims. [0027] FIG. 2 illustrates an example electronic ecosystem 214 that can be managed by an ecosystem provider, e.g., a company. The electronic ecosystem 214 can be implemented so that application developers such as developer 204 can create applications for mobile devices such as mobile device 200 and remote mobile device 202 . Generally, a developer 204 can in an example embodiment have access to a computer system that can include components similar to those described in FIG. 1 . The developer 204 can in this example embodiment obtain a software development kit from the ecosystem provider by registering with the provider and/or pay a fee. Once the developer 204 obtains the software development kit it can be installed and used to enhance the design, development, and management of applications, e.g., videogames, word processing programs, etc. The software development kit in an example embodiment can include a large library of useful functions that are provided in order to increase code reuse across projects. For example, in an embodiment the software development kit can be thought of as the skeleton that provides libraries that enable low level functions. This type of software development kit allows developers to concentrate on developing their application instead of working out the low level details of coding for a specific machine environment. In an embodiment the applications and libraries can be developed in an intermediate language that is separate from any native instruction set of a processor. The software development kit can be used to generate applications in this intermediate language that execute in a software environment that manages the application's runtime requirements. The software environment can include a runtime, e.g., a virtual machine, that manages the execution of programs by just in time converting the instructions into native instructions that could be processed by the processor. [0028] Once the application is developed a compiled version of it can be submitted to a validation system 212 that can be maintained by the ecosystem provider. For example, in an embodiment the application can be transmitted to the ecosystem provider as a package of assemblies, e.g., executables, libraries obtained from the software development kit, and any libraries developed for the application by the developer 204 . Generally, the validation system 212 can in an embodiment include circuitry for a file parser 216 , a verification system 218 , and a signing system 220 each of which can include components similar to those described in FIG. 1 . For example, file parser 216 can in one embodiment include circuitry, e.g., a processor configured by a program, for identifying assemblies that include executables. In this example embodiment the instructions of the application submitted by the developer 204 can be verified and stored in a container that includes a digital signature. [0029] Once the application is verified it can be submitted to a community feedback server 206 . The community feedback server 206 can generally be configured to store newly developed applications and transmit the new applications to peer reviewers 208 and 210 in response to requests. In at least one example embodiment the peer reviewers 208 can add to the application by downloading the source code of the application and use a copy of the software development kit to add to the application. In this example if the application includes more than source code then the validation system 212 may be invoked before it can be redistributed to peer reviewers. [0030] After the application is verified it can be stored in an electronic market place 222 that can also include components similar to those described in FIG. 1 . The electronic market place 222 can additionally include circuitry configured to sell copies of the application to members of the public. The electronic market place 222 can be configured to transmit the application in the container to either the mobile device 200 over a wireless/wired network connection or to a computer (not shown) where it can then be transmitted to the mobile device over a local connection. [0031] Referring now to FIG. 3 , it illustrates an example container 300 that can be transmitted to the mobile device 200 from an electronic market place 222 . For example, in an embodiment of the present disclosure each application can be stored in its own container 300 . The container 300 in an embodiment can be an electronic wrapper and the information inside the wrapper can be signed with a private key by the signing system 220 of FIG. 2 . In this example, the signing system 220 can embed a digital signature 306 in the container 300 so that the mobile device 200 can determine that the container 300 is authentic. Continuing with the description of FIG. 3 , the container 300 in this example may contain one or more assemblies such as assemblies 302 - 304 . For example, in an embodiment of the present disclosure the software development kit can be used to generate software packages for a given platform. The assemblies 302 - 304 in this example can effectuate the application and contain information that can be used by a runtime to find, locate, and execute the application on the platform. As is illustrated by FIG. 3 , in one embodiment each assembly can include intermediate language instructions 310 , e.g., machine independent partially compiled code, and metadata 308 that describes the intermediate language instructions. The metadata in an embodiment can describe every type and member defined in the intermediate language instructions in a language-neutral manner so as to provide information about how the assembly works. [0032] Continuing with the description of FIG. 3 , in an embodiment of the present disclosure an assembly may include a certificate 312 . For example, the certificate 312 is indicated in dashed lines which are indicative of the fact that only certain assemblies may include certificates in embodiments of the present disclosure. For example, the ecosystem provider may only embed certificates in assemblies that were developed by the ecosystem provider. In other example embodiments the ecosystem provider may embed certificates in assemblies that were coded by a trusted third party, e.g., a company that the ecosystem provider has a business relationship with. The certificate 312 in embodiments of the present disclosure can be used by the mobile device 200 to determine whether the instructions that effectuate an assembly have been scrutinized by the ecosystem provider to ensure that the assembly can not be used in a malicious way and, for example, determine which managed libraries can be called by the application. A certificate in embodiments of the present disclosure can be similar to a digital signature; however in certain instances the certificate can convey different information than the digital signature, e.g., a certificate may indicate a resource permission level for the assembly whereas the signature may be used as a source identifier. [0033] Referring now to FIG. 4 , it illustrates an example mobile device 200 that can be used in embodiments of the present disclosure. For example, mobile device 200 can include a mobile phone, a personal data assistant, or a portable media player, e.g., a mobile device configured to store and play digital content such as video, audio, and/or execute applications. As was mentioned above, a major concern with opening up a mobile device 200 to third party applications is that an attacker could attempt to compromise the mobile device 200 in order to obtain DRM keys, device keys, user data and the like. Generally, in some closed mobile devices the software stored on mobile device 200 can be considered native, e.g., the instructions can be written to run on the physical processor of hardware 402 and if an individual could access the native code they could potentially access any information the device stores. In closed mobile devices the native code is protected by scrutinizing the code prior to commercializing the product, e.g., by inspecting the code to determine that it does not include anything that could be exploited to compromise and/or damage the mobile device 200 , and coding the native software in such a way to prevent the mobile device 200 from executing any third party code. The ecosystem provider can ensure that the mobile device 200 does not execute third party code by checking the authenticity of each piece of software prior to allowing it to execute. If any portion of the system software can't be authenticated, the mobile device 200 can be configured to refuse to startup. For example, when the mobile device 200 is powered on a boot loader stored in hardware 402 can be authenticated, e.g., a digital signature of the boot loader can be checked. The boot loader can in turn authenticate and load the operating system 404 . The operating system 404 in this example embodiment can include an audio driver 416 , a secured store 418 , e.g., a secured area of memory that includes device secrets, a network driver 420 , and a graphics driver 422 . The operating system 404 in turn can authenticate native application program interfaces used to invoke operating system methods, the shell 408 , e.g., the user interface of the operating system, and a title player 410 , e.g., a native executable that launches applications and hosts them within its process. [0034] As depicted by FIG. 4 , in an embodiment the preceding portion of the components of the mobile device 200 can be considered the trusted layer of software, e.g., native software developed by the ecosystem provider, that can be stored in firmware of the mobile device 200 . In embodiments of the present disclosure however the ecosystem provider may want to allow third party applications to execute on mobile device 200 . Since these third party applications were not developed by the ecosystem provider, and thus may not be been stored in the firmware of the mobile device 200 , a mechanism needs to be put in place to ensure that the managed application 412 are not given the same level of trust as the trusted software. Third party code may need to remain un-trusted because in at least one embodiment of the present disclosure the core functionality of the mobile device, e.g., graphics processing, networking, memory management, and/or audio, are implemented by operating system methods to improve system performance and the operating system itself may lack a way to gate access to the core functionality. Thus the ecosystem provider has to expose an interface to the operating system 404 and protect the interface from being accessed by malicious code. In order to prevent the managed application 412 from invoking native methods, or having unrestricted access to memory, an arbitration layer including a runtime framework 414 can be instantiated that gates access to the operating system 404 . In example embodiments of the present disclosure when a managed application 412 attempts to access an operating system resource the runtime framework 414 can be configured to determine whether the managed application 412 has permission to access such a resource and either allow or deny its request. [0035] Referring now to FIG. 5 it depicts an example arbitration layer that can be used to implement aspects of the present disclosure. For example, FIG. 5 depicts a managed application 412 that can be, for example, a videogame, a word processing application, a personal information manager application or the like that can access native resources of the operating system 404 via at least one managed library. In order to invoke the functionality of the operating system 404 at least one managed library can be selectively exposed to the managed application 412 via a manager 516 that can be configured to restrict the third party application's access to resources other than those provided by one or more select libraries. In embodiments of the present disclosure, a managed library 514 can be dynamically loaded at runtime depending on what dependencies are required for the managed application 412 . In an embodiment the managed library 514 can be operable to access any native resource at runtime therefore the manager 516 needs to be configured in this example to deny a managed application's request to access native resources and restrict access to only but a few select managed libraries. As illustrated by FIG. 5 , the arbitration layer in this example embodiment can additionally include a runtime host 518 that can in certain embodiments be configured to call methods of the operating system 404 that actually implement the requests of the application. [0036] Continuing with the description of FIG. 5 , in an embodiment title player 410 can be configured to load and authenticate runtime host 518 , manager 516 , managed library 514 , and managed application 412 . For example, in an embodiment runtime host 518 , manager 516 , and managed library 514 can each include digital signatures that can be authenticated by the title player 410 prior to execution to ensure that they had not been tampered with. The title player 410 can check a digital certificate for each managed assembly to determine what privileges they have prior to loading them. When the title player 410 loads a managed assembly, e.g., a part of the managed application 412 or a managed library 514 , it can be configured to check the assembly's certificate to determine what privileges to grant to it. In an embodiment each managed application 412 can include a certificate that is associated with a set of privileges, e.g., the certificate can itemize the rights or the certificate can reference a set of rights that can be stored in a table of the secured store 418 . The title player 410 can check the authenticity of the assembly and if it is legitimate the title player 410 can check the certificate to determine what privileges should be granted. The title player 410 can obtain a set of privileges and make them available to the manager 516 so that the manager 516 can enforce the privileges by selectively granting or denying a managed application's access requests to certain managed libraries 514 . In the same, or other embodiments, if a managed third party application lacks a certificate 312 the title player 410 can be configured to determine that it has no privileges and direct the manager 516 to prevent the assembly from invoking any native resources such as operating system methods or native libraries, as well as denying the use of any managed library 514 for which possession of such a certificate is required. [0037] The following figures depict a series of flowcharts of processes. The flowcharts are organized such that the initial flowcharts present processes implementations via an overall “big picture” viewpoint. Those having skill in the art will appreciate that the style of presentation utilized herein (e.g., beginning with a presentation of a flowchart(s) presenting an overall view and thereafter providing additions to and/or further details in subsequent flowcharts) generally allows for a rapid and easy understanding of the various operational procedures. [0038] Referring now to FIG. 6 , it illustrates example operations related to securing a computing device including operations 600 , 602 , and 604 . As is illustrated by FIG. 6 , operation 600 begins the operational procedure and operation 602 illustrates granting, to a managed library, access to native resources of an operating system in response to validating a digital certificate associated with the managed library. For example, and referring to FIG. 5 , in an embodiment of the present disclosure a managed library 514 can be granted access to native resources of an operating system. In this example the managed library 514 can be considered managed because the instructions that effectuate it can be executed within virtual machine such as the common language runtime or java virtual machine. The manager 516 can be configured to grant the managed library 514 access rights to a native operating system resource by allowing it to be loaded into main memory after verifying the authenticity of a digital certificate 312 . The digital certificate 312 can evidence that the managed library 514 includes scrutinized code that was developed by, for example, the ecosystem provider. In one embodiment the manager 516 can be configured to check the digital certificate 312 in order to protect the operating system 404 . The operating system in this example may not have the ability to protect itself from malicious attacks, e.g., the operating system 404 may not implement kernel mode and user mode permission levels. In this example embodiment the resources of the operating system 404 can be protected by a layer of security enforced by the manager 516 . In the same or other embodiments native instructions may have privileges to access any resource of the mobile device 200 and the operating system 404 may not have a native ability to enforce security policies. In this example embodiment if the native instructions were accessed by a malicious third party application then an attacker could potentially access any system resource such as a device key, a display driver, and/or damage the mobile device 200 . In another example embodiment the operating system 404 may include a native ability to protect itself. In this example the operating system 404 can be protected by an additional layer of security enforced by the manager 516 . [0039] Continuing with the description of FIG. 6 , operation 604 illustrates denying, to a managed application, access to native resources of the operating system, wherein the managed application includes a digital certificate authorizing the managed application to access a specific native resource of the operating system through the managed library. For example, and in addition to the previous example the ecosystem provider may want to allow third party applications such as videogames to be developed and allowed to execute on the mobile device 200 . In certain embodiments however the ecosystem provider may not want third party managed applications to access any native resources such as native dynamically linked libraries, kernel functions, and/or drivers. Thus, in this example embodiment the manager 516 can be configured to prevent the managed application 412 from accessing such native resources and/or terminate the managed application 412 if the managed application 412 attempts to access such a resource. Managed application 412 can in an embodiment be stored in a digitally signed container such as container 300 of FIG. 3 . When the managed application 412 is launched, the container 300 can be checked to determine that it has not been tampered with, e.g., the digital signature 306 can be checked. If the digital signature 306 is valid, then the assemblies that effectuate the managed application 412 can be loaded into runtime space. Each assembly in the container 300 can be checked for a certificate 312 that indicates which managed libraries the application can call. The list of callable managed libraries can be stored in a table made accessible to the manager 516 and the manager 516 can be configured to prevent the managed application 412 from accessing native resources and/or managed libraries outside of the ones listed in the certificate 312 . In this example the managed application 412 can be terminated if the managed application 412 attempts to access such a resource. [0040] Referring now to FIG. 7 , it depicts an alternative embodiment of the operational procedure of FIG. 6 including operations 706 , 708 , 710 , 712 , and 714 . Operation 706 illustrates the operational procedure of FIG. 6 , wherein the managed library comprises instructions generated by a trusted developer. For example, in one embodiment the managed library can be effectuated by intermediate language instructions and metadata. In this example the managed library 514 can have been generated by a trusted provider such as the ecosystem provider and/or a third party corporation that the ecosystem provider has a business relationship with. In this example the ecosystem provider can ensure that the managed library does not include malicious code or code that could be used in a malicious way by fully testing the code prior to releasing it to the public. In this example the ecosystem provider can ensure that the managed library can only be used to perform its indented function(s). [0041] Continuing with the description of FIG. 7 , it additionally illustrates operation 708 that depicts verifying a digital signature associated with a container that includes the managed application; and loading the managed application. For example, in an embodiment of the present disclosure the title player 410 can be configured to load the managed application 412 in response to user input and determine that the managed application 412 is un-trusted. In an embodiment the ecosystem provider may associate a certificate 312 with the managed application 412 that identifies it as un-trusted and list one or more managed libraries that the un-trusted application can call. In this example embodiment the ecosystem provider may determine that code developed by a third party can access managed libraries that the ecosystem provider developed and the manager 516 can be configured to prevent the managed application 412 from accessing native system resources and/or terminate the managed application 412 if it attempts to access native resources or managed libraries for which the managed application has not been authorized to access. [0042] Continuing with the description of FIG. 7 , it additionally illustrates operation 710 that shows the operational procedure of FIG. 6 , wherein the native functions of the operating system are accessed through instructions for a runtime host, further wherein the instructions for the runtime host are effectuated by native instructions. For example, in an embodiment of the present disclosure the title player 410 can include instructions configured to validate a digital signature of a runtime host 518 and launch the runtime host 518 . For example the instructions for the runtime host 518 can include an encrypted hash of the instructions that effectuate it. A corresponding public key can be stored in the secured store 418 of the mobile device 200 and made available when title player 410 attempts to load the runtime host 518 . The runtime host 518 in an example embodiment can be authenticated prior to execution because the instructions that effectuate the runtime host 518 can be stored in mass storage such as a hard drive or flash memory in at least one embodiment. In this example an attacker could attempt to replace the mass storage device with a malicious copy that could include code to attempt to access the secured store. In this embodiment the risk from such an attack can be mitigated by validating the runtime host 518 prior to execution. [0043] In an example embodiment when the mobile device 200 is powered on the runtime host 518 may be loaded into main memory after a user uses the shell 408 to execute the videogame. For example, in an embodiment of the present disclosure the mobile device 200 may launch native instructions from the trusted layer of software when the mobile device 200 is powered on and only load the arbitration layer of FIG. 4 and FIG. 5 if a user of the mobile device 200 wants to execute a third party application. In this example when the title player 410 is launched it can in turn launch the runtime host 518 after it authenticates the runtime host's digital signature. [0044] Continuing with the description of FIG. 7 , it additionally illustrates operation 712 that shows verifying a digital signature associated with the managed library; and loading the managed library. For example, in an embodiment of the present disclosure the title player 410 can include instructions configured to validate a digital signature of a container 300 that stores the managed library 514 and load the managed library 514 . For example, in an embodiment of the present disclosure the container 300 can include a digital signature encrypted with a private key. A corresponding public key can be stored in the secured store 418 of the mobile device 200 and made available when title player 410 attempts to load the managed application 412 . [0045] Continuing with the description of FIG. 7 , it additionally illustrates operation 714 that shows wherein the managed application includes instructions verified by a remote device, further wherein the verified instructions are type safe. For example, in an embodiment of the present disclosure the managed application 412 can be verified by the ecosystem provider prior to distribution to the mobile device 200 . For example, in an embodiment verification can include examining the instructions and metadata associated with the managed application 412 to determine whether the code is type safe, e.g., that it accesses members of an object in well defined and allowed ways, it only accesses memory locations it is authorized to access, and/or that it does not access any private members of an object. During the verification process, the managed application's instructions can be examined in an attempt to confirm that the instructions can only access approved memory locations and only call methods through properly defined types. [0046] Referring now to FIG. 8 , it depicts an operational flowchart for practicing aspects of the present disclosure including operations 800 , 802 , 804 , 806 , and 808 . Operation 800 beings the operational procedure and operation 802 illustrates receiving, by a manager, a request from a managed application to access a native system resource through a managed library. For example, a manager 516 can receive a request from a managed application 412 to access an operating system resource such as an application program interface for the operating system 404 via managed library 514 . In an embodiment of the present disclosure a managed application 412 such as a contact book application may attempt to access a resource of the operating system 404 such as a list of phone numbers stored in the secured store 418 via the functionality of a contact book managed library. In this example graphics, audio, and network support may be integrated with the operating system 404 and an application that has access to the operating system 404 could for example, potentially have the ability to access memory reserved to store device secrets such as DRM keys. In this example the managed application 412 may send a request to a manager 516 to access the operating system 404 via the managed library 514 . In this example both the managed application 412 and the managed library 514 can be considered managed because the instructions that effectuate them can be executed within virtual machine such as the common language runtime or java virtual machine. In this example the managed application 412 can be considered pure managed code because the managed application 412 is not allowed to access native resources and the managed library 514 can be considered non-pure managed code which indicates that the library is allowed to access some of the native resources. [0047] Continuing with the description of FIG. 8 , operation 804 illustrates authorizing, by the manager, the request to access the native system resource through the managed library, wherein the manager includes information that identifies managed libraries that the managed application is authorized to access, further wherein the manager is effectuated by native instructions. For example, and referring to FIG. 5 , the manager 516 can be configured to allow the managed application 412 to access the managed library 514 in order to, for example, access a method of the graphics driver 422 for drawing a sprite at a certain location on a display. The manager 516 in this example embodiment can include a software process effectuated by native code. In this example the manager 516 can be configured to receive the request from the managed application 412 and determine whether the managed application 412 has permission to call the managed library 514 by accessing a table of information stored in memory such as RAM. [0048] For example, in an embodiment of the present disclosure the manager 516 can store a table of information that includes a list of managed libraries that the managed application 412 can access. In the case of a pure managed assembly the list can include information that explicitly denies any attempt at calling native code or accessing reserved memory locations. If, for example, the pure managed assembly attempts to call a native dynamically linked library, access a memory location that stores a DRM key, or access a managed library that it is not permitted to access, the manager 516 can determine that a security violation occurred and terminate the managed application 412 . In an example embodiment the list of managed libraries that the managed application 412 can access can be stored in the secured store 418 . In this example the assembly 302 - 304 of FIG. 3 that contains the managed application 412 can be checked for a digital certificate 312 . In the instance where the assembly does not include a certificate 312 the manager 516 can be configured to determine that the assembly is un-trusted and load a predefined list of managed libraries that the managed application 412 can access into the table. [0049] In another embodiment instead of having a two tier trust system, e.g., a system where managed applications are granted full permission or no permission based on the presence or absence of a certificate 312 , a multi-tiered system could be implemented by, for example, embedding different types of certificates in the assemblies or by including different sets of privileges in the certificates. In the first example the secured store 418 can be configured to include a table associating different types of certificates with different privileges, e.g., one certificate could be associated with a table entry that indicates that the managed application 412 is allowed to access a method of a network driver 420 and another certificate could be associated with a table entry that indicates that the managed application 412 is allowed to access an address book of a user stored in the secured store 418 . The operating system 404 or the title player 410 in this example could decrypt the certificate 312 and associate a number in the certificate to a set of privileges stored in the secured store 418 . In another embodiment the certificate itself could include information that identifies a set of operating system resources that the managed application 412 is allowed to access. In this example the operating system 404 or the title player 410 can be configured decrypt the certificate and compare a hash of the information in the certificate to an expected value. If the certificate is valid, the set of privileges can be retrieved from the certificate. Regardless as to how the operating system 404 or the title player 410 determines a managed application's privileges, the privileges can be transmitted to the manager 516 and the manager 516 can be configured to monitor instructions issued by the managed application 412 to determine whether it is attempting to access native code and/or load managed libraries that are not within the scope of its certificate. [0050] Continuing with the description of FIG. 8 , it additionally illustrates operation 806 that shows authorizing, by the manager, the request to access the native system resource by the managed library, wherein information that identifies that the managed library is authorized to access the native system resource was obtained from a digital certificate associated with the managed library. For example, in an embodiment of the present disclosure the manager 516 can be configured to authorize the managed library's request to access a native system resource by, for example, allowing a managed library 514 to execute when the managed application 412 calls the managed library 514 . For example, in this embodiment the ecosystem provider may create a clear trust boundary between the managed application 412 and the operating system 404 by providing an arbitration layer that can include code that was developed by the ecosystem provider. In this example the arbitration layer can be used by un-trusted third party code to access native operating system resources in a well defined and trusted way. In one example embodiment the managed library 514 can be loaded as needed at runtime by, for example, the title player 410 . During the load process the manager 516 can be configured to request a level of trust for the newly loaded library by calling native code such as code of the operating system 404 or the title player 410 . The native code in this example embodiment can be configured to determine whether the assembly is trusted or not. In one embodiment the native code can be configured to check the authenticity of a certificate 312 stored in the managed library 514 . If the certificate is valid, e.g., it can be decrypted by a public key stored in the secured store and its hash matches an expected value, the operating system 404 or the title player 410 can be configured to grant the managed library 514 full rights to access unallocated memory, access operating system functions, or invoke native dynamically linked libraries. [0051] For example and continuing with the description of FIG. 8 , operation 808 illustrates sending, by the managed library, a request to access the native system resource to a runtime host, wherein the runtime host is effectuated by native instructions. For example, in an embodiment of the present disclosure an operating system function can be requested by a managed application 412 and a managed library 514 can be used to implement the request by calling a runtime host 518 . The runtime host 518 in this example embodiment can be effectuated by native code and can be used so that only native code accesses the operating system 404 . In this example runtime host 518 can be a native dynamically linked library that includes application program interfaces for the functions that are made available to managed application 412 . In this embodiment the runtime host 518 can receive an instruction from, for example, a just in time complier that received an instruction from the managed library 514 and compiled it into native code that can be processed by the runtime host 518 . [0052] Continuing with the description of FIG. 8 , operation 810 illustrates accessing, by the runtime host, the native system resource. For example, the runtime host 518 can be configured in this example to receive the instruction from the managed library 514 and invoke an operating system function operable to effect the request. For example, in an embodiment of the present disclosure mobile device 200 can be a cellular phone and managed application 412 may include a music player. In this example embodiment the music playing functionality could be integrated into the operating system 404 and in order to play a song an operating system method would need to be invoked. In this example the music player could access a managed library 514 that includes an application program interface for the music player. In this example the managed library 514 could be developed by the ecosystem provider whereas the managed application 412 could have been developed by a different entity, e.g., a different company or an individual. Thus, in this example when the managed library 514 is loaded its certificate can be validated and it can be authorized to access native resources. The managed library 514 for the music player can submit a request to the runtime host 518 and the runtime host 518 can be configured to invoke the music player driver of the operating system 404 and the song can be played. [0053] Referring now to FIG. 9 , it illustrates an alternative embodiment of the operational procedure 800 of FIG. 8 including the additional optional operations 912 , 914 , 916 , and 918 . Referring to operation 912 , it illustrates the operational procedure 800 of FIG. 8 , wherein the native system resource is accessed from a platform invoke. For example, in an embodiment of the present disclosure a platform invoke can be used by managed assemblies to access a native system resource of the operating system 404 , e.g., a native dynamically linked library. For example, in this embodiment when the platform invoke is used to call a function of the operating system 404 the interface for the function can be located and loaded into memory. The address of the function can be obtained and an argument for the function can be pushed to the interface. In a specific example a third party application could be a videogame that requires functionality of a graphics driver of the operating system in order to draw sprites. In this example the videogame can pass a request to draw the sprite to a managed graphics library that could for example, contain low-level application programming interface methods for drawing sprites. In this example the managed graphics library can receive the request and perform a platform invoke on, for example, runtime host 518 . The interface of the runtime host 518 can be loaded into memory and the argument, e.g., the request to draw the sprite, can be pushed into a memory area reserved for the runtime host 518 . [0054] Referring again to FIG. 9 , it additionally depicts operation 914 that illustrates executing a title player, wherein the title player is effectuated by native instructions. For example, in an embodiment of the present disclosure the mobile device 200 can include instructions for a title player 410 . For example, in one embodiment the instructions that effectuate the title player 410 can be native to the mobile device 200 , e.g., they can be instructions configured to execute on a processor of the hardware 402 of FIG. 4 . In an embodiment of the present disclosure the title player can 410 can be stored in firmware of the mobile device 200 and can include a digital signature. In this example embodiment the title player 410 can be used to execute a managed application 412 and can be invoked by the shell 408 . For example, a user can interact with the shell 408 and select an option to launch a program operable to pull stock information from the internet. In response to the request the shell 408 , e.g., native instructions, can launch the title player 410 . In at least one embodiment the shell 408 and/or the operating system 404 can be configured to check the digital signature of the title player 410 prior to execution to determine whether the title player 410 is authentic. [0055] Continuing with the description of FIG. 9 it additionally depicts operation 916 that depicts determining, by the manager, that the managed application is permitted to access a premium native system resource, wherein information that identifies that the managed application is permitted to access the premium native system resource was obtained from a premium certificate associated with the managed application. For example, in an embodiment of the present disclosure a managed application 412 can be configured to have a premium level of access to the native functionality of the mobile device 200 via a premium managed library. For example, in an embodiment the managed application 412 may receive access to additional resources of the mobile device 200 , e.g., the developer of the managed application 412 may be considered a trusted developer or other business reasons may contribute to the third party developer being granted to a higher level of resources. In this example the managed application 412 may be developed using the development studio that relies on a plurality of class libraries to implement the low level application program interfaces and these libraries may, for example, be provided by the ecosystem provider. In this example the ecosystem provider may develop a class library that has access to premium functionality of the operating system 404 such as a library that makes a DRM protected music file available to a third party application. In this embodiment the managed application 412 can be associated with a premium certificate that permits it to have access to a DRM protected audio stream. When the managed application is loaded the manager 516 can be provided with information that can be used to authorize a request to access the premium managed library. [0056] Continuing with the description of FIG. 9 , it additionally depicts operation 918 that illustrates the procedure 800 , wherein the managed application is stored in a container that includes a digital signature. For example, in an embodiment of the present disclosure the managed application can be stored in a container such as the container 300 of FIG. 3 . For example, in an embodiment of the present disclosure the ecosystem provider can include techniques for storing managed applications in containers and digitally signing them. In this example the ecosystem provider can be configured to generate a hash of the information in the container and encrypt the hash using a private encryption key. A corresponding public key can be stored in the secured store 418 of the mobile device 200 . When the mobile device 200 opens the container 300 , the public key can be used to decrypt the hash. A hash of the container 300 can be calculated and compared to the expected hash. If the hashes match then the mobile device 200 can be configured to allow the managed application from the container 300 to execute. [0057] Referring now to FIG. 10 , it depicts an alternative embodiment of the operational procedure 800 of FIG. 9 including the additional operations 1020 , 1022 , and 1024 . Referring now to operation 1020 , it illustrates validating, by the title player, a digital signature associated with the runtime host; and executing the runtime host. For example, in an embodiment of the present disclosure the title player 410 can include instructions configured to validate a digital signature of the runtime host 518 and launch the runtime host 518 . For example, in an embodiment of the present disclosure the instructions that effectuate the runtime host 518 can be stored in mass storage along with a hash of the runtime host 518 encrypted with a private key. A corresponding public key can be stored in the secured store 418 of the mobile device 200 and made available when title player 410 attempts to load the runtime host 518 . If the runtime host 518 is authentic then it can be loaded by the title player 410 . [0058] In an example embodiment when the mobile device 200 is powered on the runtime host 518 may be loaded into memory after a user uses the shell 408 to execute the managed application 412 . For example, in an embodiment of the present disclosure the mobile device 200 may launch native instructions from the trusted layer of software when the mobile device 200 is powered on and only load the arbitration layer of FIG. 4 and FIG. 5 if a user of the mobile device 200 wants to execute a managed application 412 . In this example when the title player 410 is launched it can in turn launch the runtime host 518 after it authenticates the runtime host's digital signature. [0059] Continuing with the description of FIG. 10 , operation 1022 illustrates validating, by the title player, a digital signature associated with the manager; and executing the manager. For example, in an embodiment of the present disclosure the title player 410 can include instructions configured to validate a digital signature of the manager 516 and launch the manager 516 . For example, the instructions that effectuate the manager 516 can be stored in mass storage, e.g., flash or a hard disk, along with a hash of the instructions encrypted with a private key. A corresponding public key can be stored in the secured store 418 of the mobile device 200 and made available when title player 410 attempts to load the manager 516 . If the manager 516 is authentic then it can be loaded by the title player 410 . [0060] In an example embodiment when the mobile device 200 is powered on the manager 516 may be loaded into memory after a user uses the shell 408 to execute the managed application 412 . For example, in an embodiment of the present disclosure the mobile device 200 may launch native instructions from the trusted layer of software when the mobile device 200 is powered on and only load the arbitration layer of FIG. 4 and FIG. 5 if a user of the mobile device 200 wants to execute a managed application 412 . In this example when the title player 410 is launched it can in turn launch the manager 516 after it authenticates the manager's digital signature. [0061] Continuing with the description of FIG. 10 it additionally depicts operation 1024 that shows loading, by the title player, the managed application; determining, by the title player, that the managed application is un-trusted; and denying, by the manager, the managed application access to native system resources. For example, in an embodiment of the present disclosure title player 410 can be configured to load the managed application 412 in response to user input and determine that the managed application 412 is un-trusted. For example, the managed application 412 can be considered un-trusted if it lacks a digital certificate 312 . In this embodiment the ecosystem provider may not associate a digital certificate with the managed application 412 if it was developed by a third party such as a remote company or individual. In another embodiment the ecosystem provider may associate a certificate with the managed application 412 that identifies it as un-trusted. In either example embodiment the ecosystem provider may determine that code developed by a third party can be configured to access managed libraries that the ecosystem provider developed and the manager 516 can be configured to prevent the managed application 412 from accessing native resources such as native dynamically linked libraries. In this example, the title player 410 can open the managed application and determine that it is to be considered un-trusted. The title player 410 in this example can make this information available to the manager 516 that can in turn monitor instructions that the third party application issues. In the event that the application attempts to access native instructions of the system, e.g., an operating system method, a security violation can be detected and the manager 516 can terminate the managed application 412 . [0062] Referring now to FIG. 11 , it depicts an alternative embodiment of the operational procedure 800 of FIG. 9 including the additional operations 1126 , and 1128 . Referring now to operation 1126 , it illustrates transmitting the container to a remote mobile device. For example, and referring to FIG. 2 , in an embodiment of the present disclosure a mobile device 200 can include a wireless and/or wired network connection to a remote mobile device 202 . In this example the mobile device 200 can share the managed application 412 with the remote mobile device 202 . For example, the remote mobile device 202 could use the shared application for a limited amount of time or a limited amount of executes before the managed application 412 locks. In this example the remote mobile device 202 could access the electronic market place 222 and purchase a full license to the managed application 412 . [0063] Continuing with the description of FIG. 11 , it additionally illustrates operation 1128 that illustrates an alternative embodiment of the operational procedure of FIG. 9 , wherein the managed application includes instructions verified by a service provider, further wherein the verified instructions are type safe instructions. For example, in an embodiment of the present disclosure the managed application 412 can be previously verified by the ecosystem provider prior to distributing the managed application 412 to the mobile device 200 . For example, in an embodiment verification can include examining the instructions and metadata associated with the managed application 412 to determine whether the code is type safe, e.g., that it accesses members of an object in well defined and allowed ways, it only accesses memory locations it is authorized to access, and/or that it does not access any private members of an object. During the verification process, the managed application's instructions can be examined in an attempt to confirm that the instructions can only access approved memory locations and/or call methods only through properly defined types. [0064] Referring now to FIG. 12 , it illustrates an example operational procedure related to publishing videogames configured to execute on a mobile device including operations 1200 , 1202 , 1204 , 1206 , and 1208 . Operation 1200 begins the operational procedure and operation 1202 illustrates receiving a package from a networked computer system. For example, and referring to FIG. 2 , a network adaptor of a validation system 212 can receive a package from a networked computer system that can include, but is not limited to, a community feedback server 206 , a peer reviewer, and/or a developer 204 . In an example embodiment of the present disclosure the package can include one or more assemblies, e.g., executables and dynamically linked libraries. In one example the libraries could be made by the developer 204 and/or by the ecosystem provider. [0065] Continuing with the description of FIG. 12 , operation 1204 illustrates identifying an executable in the package. For example, in an embodiment of the present disclosure the package can be received by the validation system 212 and sent to a file parser 216 . For example, the file parser 216 can be configured to scan the package for assemblies that contain executables. For example, in one embodiment the parser 216 can be configured to check the entire package for .exe files, and/or files that include executables stored in, for example, images and generate a list of all .exe and .dll files in the package. [0066] Continuing with the description of FIG. 12 , operation 1206 illustrates verifying managed metadata associated with the executable, wherein the managed metadata describes the structure of executable, further wherein verifying the managed metadata includes inspecting the managed metadata at runtime to determine that the executable includes type safe code. For example, in an embodiment of the present disclosure after the file parser 216 identifies executables in the package a list of executables and the package can be transmitted to the file verification system 218 . The verification system 218 in this example embodiment can be configured to determine whether the executables are valid by checking, for example, certain values in the header and the metadata. For example, in an embodiment of the present disclosure the verification system 218 can be configured to validate the metadata by exercising it. As was described above, in one embodiment a package can be submitted that can include one or more assemblies each of which can include intermediate language instructions and metadata. In this example the verification system 218 can be configured to inspect each assembly's metadata using a process called reflection, and inspect each assembly's managed instructions. The reflection process includes an application programming interface that can walk through the managed metadata and monitor the runtime characteristics of the metadata to identify malicious instructions that could, for example, attempt to access native code or access the secured content on the mobile device 200 . In addition, the reflection API can be configured to determine whether the instructions are type safe, e.g., that it accesses members of an object in well defined and allowed ways, it only accesses memory locations it is authorized to access, and/or that it does not access any private members of an object. [0067] In another example embodiment the verification system 218 can be configured to identify managed libraries that the executables attempt to link at runtime and compare them to a list of approved managed libraries. The verification system 218 can be configured in this example to reject any executable that attempts to link a restricted library or a library that the application should not have access to, e.g., a videogame should not have access to a managed library that can access device keys stored in a secured store 418 . [0068] Continuing with the description of FIG. 12 , operation 1208 illustrates storing the verified executable in a digitally signed container. For example, once the executable is verified by the verification system 218 it can be sent to a signing system 220 configured to repackage the assemblies into a container such as container 300 of FIG. 3 and digitally sign the container 300 . The signing system 220 in this example can be configured to generate a hash of the instructions in the container 300 and encrypt the hash with a private key. In this example a mobile device 200 can be configured to include a public key usable to decrypt the container 300 and compare the hash of the information in the container 300 to the expected result. Once the container 300 is signed it can in one embodiment transmit the container 300 to an electronic market place 222 where it can be purchased by a user of the mobile device 200 and downloaded. In another embodiment the signing system 220 can be configured to include information that identifies what managed libraries can be accessed by the container 300 in digital certificates for each assembly stored in the container 300 . [0069] Referring now to FIG. 13 , it illustrates an alternative embodiment of the operational procedures of FIG. 12 including the additional operations 1310 , 1312 , and 1314 . Referring now to operation 1310 , it illustrates transmitting the digitally signed container to a mobile device. For example, in an embodiment of the present disclosure the container 300 can be transmitted to a mobile device 200 after, for example, it is purchased. As stated above, in an embodiment of the present disclosure the ecosystem provider can maintain an electronic market place 222 that is configured to allow users to purchase games that are submitted by third party developers such as companies and/or individuals that obtain the software developers kit. [0070] Continuing with the description of FIG. 13 , it additionally illustrates operation 1310 that depicts determining that the executable in the file includes managed dependencies. For example, in at least one example embodiment the verification system 218 can be additionally configured to determine what dependencies are required by the executable and either reject the package or forward the package to the signing system 220 . For example, the verification system 218 in this embodiment can be configured to identify the set of assemblies in the applications' runtime profile. The verification system 218 in this example can identify each assembly and determine whether the assemblies are developed by the ecosystem provider or the developer 204 . In the instance where an identified assembly is developed by the ecosystem provider the verification system 218 can be configured to determine whether the assembly is on a white list for the type of managed application, e.g., the verification system 218 can check the white list to determine whether an assembly that can access the secured store 418 is allowed to be called by a videogame. If the assembly is not on the white list, the process can end and a message can be sent to the developer 204 stating that the assembly is not accessible to, for example, the type of managed application and/or the developer 204 , e.g., the developer 204 may not have trusted status. The verification system 218 in this example can additionally check to determine that native libraries are not referenced by the metadata. In a specific example, if the managed application includes a reference to a native library then the managed application can access the library and take control of the mobile device 200 . If the verification system 218 determines that the assembly references a native library the verification process can end and a message can be sent to the submitter stating that the validation process failed because a native library was referenced. [0071] Continuing with the description of FIG. 13 , it additionally illustrates operation 1312 that depicts validating header fields of the executable. For example, in an embodiment of the present disclosure the header fields of the executable can be checked by the verification system 218 to determine whether they include expected header values. For example, each executable can include one or more headers that can include information such as how the runtime environment is to map the file into memory or how configure the loader and linker. The file in this example can additionally include data directory header values that contain pointers to data. For example, in an embodiment the verification system 218 can be configured to check the header values and fail any package that includes values that are associated with files that include native instructions. [0072] The foregoing detailed description has set forth various embodiments of the systems and/or processes via examples and/or operational diagrams. Insofar as such block diagrams, and/or examples contain one or more functions and/or operations, it will be understood by those within the art that each function and/or operation within such block diagrams, or examples can be implemented, individually and/or collectively, by a wide range of hardware, software, firmware, or virtually any combination thereof. [0073] While particular aspects of the present subject matter described herein have been shown and described, it will be apparent to those skilled in the art that, based upon the teachings herein, changes and modifications may be made without departing from the subject matter described herein and its broader aspects and, therefore, the appended claims are to encompass within their scope all such changes and modifications as are within the true spirit and scope of the subject matter described herein.

Disclosed is a code verification service that detects malformed data in an automated process and rejects submission and distribution if any malicious code is found. Once the submission is verified it may be packaged in container. The container may then be deployed to a mobile device, and the public key may be used to verify that the container authentic. The device can load trusted managed libraries needed to execute the application and a manager can ensure that only trusted libraries access native resources of the device.

big_patent

BACKGROUND OF THE INVENTION [0001] This invention relates to an improved identification card. More specifically, this invention relates to an identification card containing an internal antenna and integrated circuit chip laminated between two protective, non-rigid layers onto which artwork may be printed, which are then laminated between to rigid outer layers. [0002] “Smart cards” which contain an IC chip are well known in the art and typically have been used for credit card and ATM transactions. Smart cards may either have contacts on their surface to interface with a card reader or they may be contactless cards and incorporate an antenna within the body of the card to transfer data without physical contact with a reading device. [0003] Typically smart cards have been made with a rigid core onto which an IC chip and antenna are positioned by means of glue or a mechanical device. The rigid core is then covered with a plastic, encasing the structure in a polymer. For example, U.S. Pat. No. 5,809,633 issued to Mundigl, et al. discloses a method whereby an antenna is inserted into a recess in a carrier body. U.S. Pat. No. 5,955,021 issued to Tiffany, III teaches the use of low shrinkage glue to secure the electronic components to a rigid plastic core layer, which is then placed into a bottom mold assembly. A top mold assembly is then attached to the bottom mold creating a void. Thermoplastic is then injected into the void space to secure the electronic components. Similarly, U.S. Pat. No. 6,049,463 issued to O'Malley, et al. discloses a microelectric assembly including an antenna embedded within a polymeric card by means of a mold assembly. The antenna and chip are placed into a mold and polymeric material is injected into the mold thus encasing the components. [0004] U.S. Pat. No. 6,036,099 issued to Leighton discloses a process for manufacturing a combination contact/contactless smart card via a lamination process utilizing core sheets made from polyvinyl chloride (PVC), polyester, or acrylonitrile-butadiene-styrene (ABS). In the Leighton method, a region of the card is milled to expose the contacts of the card. [0005] Due to the rigidity of the components used in the prior art cards, the electronic components cards can be subject to damage from bending stresses. Also, securing the antenna and chip with glue or a mechanical means is complicated and can needlessly increase the costs of production. Understandably, processes utilizing molds involve increased costs of tooling and production not seen in a lamination process. Both the highly plasticized poly(vinyl chloride) type and the polyester/poly(vinyl chloride) composite type can become brittle over time because of migration of the plasticizers, thus reducing the resistance of the document to cracking; such cracking renders the card unusable and vulnerable to tampering. Data that are crucial to the identification of the bearer are often covertly repeated on the document in encrypted form for data verification in a magnetic stripe, bar code, radio frequency module or integrated circuit chip. The inability to retrieve such data due to cracking renders the document invalid. In addition, many of the polyester/poly(vinyl chloride) composite documents have exhibited extreme sensitivity to combinations of heat and humidity, as evidenced by delaminating and curling of the document structure. [0006] Therefore, a need exists for a low-cost, easily constructed identification card having an antenna and chip incorporated into the body of the card, which protects these electronic components from damage. Applicants' invention relates to a unique structure capable of protecting the IC chip and antenna. Applicants' invention contains two relatively shock-absorbing layers, which may contain indicia. In an embodiment, two rigid outer laminate layers encase the relatively shock-absorbing layers, adding structural support and protection. Applicants' card differs from the prior art in that normally rigid materials are used throughout the card, thus permitting external stresses and bending to damage the delicate IC chip and antenna. In applicants' improved design, rigid outer layers disseminate external forces over a broad area of compliant layers, thus protecting the electronic components. SUMMARY OF THE INVENTION [0007] Accordingly, this invention provides an identification card comprising: [0008] a core layer comprising a silica-filled polyolefin, said core layer having a first side and a second side, [0009] at least one antenna fixed to said to said first side of said core layer, [0010] at least one computer chip electrically connected to said antenna, [0011] a bottom sheet comprising a silica-filled polyolefin attached to said first side of said core by a first adhesive layer such that said antenna and said chip are enveloped between said core and said bottom sheet. [0012] an akyld resin spid containing an anti-binding agent printed on said first side of said core layer, [0013] a first laminate layer attached to said second side of said core layer by a second adhesive layer, [0014] a second laminate layer attached to said bottom sheet by a third adhesive layer such that said core and said bottom sheet are encased between said first laminate layer and said second laminate layer. BRIEF DESCRIPTION OF THE DRAWINGS [0015] FIG. 1 of the attached drawings shows a cross-section of an identification card of the present invention. [0016] FIG. 2 of the attached drawings shows a cross-section of an alternative embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION [0017] To prepare an identification card of the present invention the first step is pre-shrinking a core layer. In order to provide an identification document having a bright white background and good color rendition, it is generally preferred that the core layer be formed from an opaque sheet of printable silica-filled polyolefin, such as the materials sold commercially by PPG Industries, Inc., Pittsburgh, Pa. under the Registered Trade Mark “TESLIN” sheet. [0018] The first indicium or indicia, which are typically the invariant information common to a large number of identification documents, for example the name and logo of the organization issuing the documents, may be formed by any known process capable of forming the indicium on the specific core material used. [0019] However, since it is usually desired to provide numerous copies of the first indicium on a large area of core layer material (in the form of a large sheet or web) in order to allow the preparation of a large number of “blank” documents at one time, a printing process such as color laser printing, is normally used to apply the first indicium. A modified laser printer useful for forming the first indicium in the present process is described in U.S. Pat. No. 5,579,694. [0020] In order to minimize the risk of damage to the fragile electronic components, preferably alkyd resin spids containing an anti-binding agent are printed onto one side of the shrunken core sheet on the side opposite from the indicia. These spids may be printed in any pattern, however, in an embodiment they are printed onto the core in a “racetrack” or oval pattern. Antennae, typically silver-epoxy antennae, are then printed onto the spids in a matching pattern. Integrated circuit chips are attached to solder bumps on the antennae in the conventional manner. [0021] The core layer with attached antennae and IC chips is then bonded to a bottom sheet of printable, silica-filled polyolefin with an adhesive layer. The adhesive layer may be composed of a number of commercially available adhesives, however, very desirably it is composed of a co-polyester based adhesive such as the adhesive sold commercially by Transilwrap, Inc., Richmond, Ind. under the name Transilwrap® TXP(3). Because IC chips are typically much thicker than the antennae, preferably recesses are cut in the TXP(3) adhesive layer to accommodate the IC chips. By removing a section of the adhesive, the identification card will be of uniform thickness. Because recesses were cut in this TXP(3) adhesive layer, in order to bond the IC chip to the bottom layer, an additional layer of adhesive is required. Although this adhesive may comprise any suitable adhesive, in the preferred embodiment it is a carboxylated polyethylene hot melt adhesive such as that manufactured by Transilwrap, Inc. and sold under the name Transilwrap® KRTY. This adhesive is applied to the bottom layer prior to assembly of the card and serves to bind the IC chip to the bottom layer. During lamination of the identification card, the TXP(3) adhesive layer will flow freely thus adhering the core sheet with the bottom sheet, sandwiching the electronic components in a bonded, flexible laminate of silica-filled polyolefin. [0022] Two layers of substantially transparent polymer are affixed to the bonded core layer/bottom layer structure. Depending upon the material used for the core layer and bottom layer, the process used to produce the first indicium and the type of substantially transparent polymer employed, fixation of the polymer layers to the core layer may be effected by heat and pressure alone. However, it is generally preferred to provide an adhesive layer on each polymer layer to improve its adhesion to the core layer. This adhesive layer may be a polyester, polyester urethane, polyether urethane or polyolefin hot melt or ultraviolet or thermally cured adhesive, and the adhesive may be coated, cast or extruded on to one surface of the polymer sheet. The polymer layers themselves may be formed from any polymer having sufficient transparency, for example polyester, polycarbonate; polystyrene, cellulose ester, polyolefin, polysulfone, or polyimide. Either an amorphous or biaxially oriented polymer may be used. Two specific preferred polyesters for use in the process of the present invention is poly(ethylene terephthalate) (PET), which is readily available commercially, for example from ICI Americas Inc., Wilmington, Del. 19850 under the Registered Trade Mark “MELINEX”, and poly(ethylene terephthalate glycol) (PETG), which is readily available commercially from Eastman Kodak Chemical, Kingsport, Tenn. The polymer layers provide mechanical strength to the image-receiving layer or layers and hence to the image(s) in the finished document. The thickness of the polymer layers is not critical, although it is generally preferred that the thickness of each polymer layer (including the thickness of its associated adhesive layer, if any) be at least about 0.1 mm, and desirably is in the range of from about 0.125 to about 0.225 mm. Any conventional lamination process may effect lamination of the polymer layers to the core layer, and such processes are well known to those skilled in the production of identification documents. [0023] The image-receiving layer of the present identification document may be formed of any material capable of receiving an image by dye diffusion thermal transfer. However, very desirably the dye diffusion thermal transfer printing step of the present process is effected by the process of U.S. Pat. No. 5,334,573. This patent describes a receiving sheet or layer which is comprised of a polymer system of which at least one polymer is capable of receiving image-forming materials from a donor sheet with the application of heat, the polymer system of the receiving sheet or layer being incompatible with the polymer of the donor sheet at the receiving sheet/donor sheet interface so that there is no adhesion between the donor sheet and the receiving sheet or layer during printing. In addition, the polymer system of the receiving sheet or layer can be substantially free from release agents, such as silicone-based oils, poly(organosiloxanes), fluorinated polymers, fluorine or phosphate-containing surfactants, fatty acid surfactants and waxes. The present process may employ any of the donor sheet/image-receiving layer combinations described in this patent. Suitable binder materials for the dyes, which are immiscible with the polymer system of the image-receiving layer, include cellulose resins, cellulose acetate butyrate, vinyl resins such as poly(vinyl alcohol), poly(vinylpyrrolidone) poly(vinyl acetate), vinyl alcohol/vinyl butyrate copolymers and polyesters. Polymers which can be used in the image-receiving layer and which are immiscible with the aforementioned donor binders include polyester, polyacrylate, polycarbonate, poly(4-vinylpyridine), poly(vinyl acetate), polystyrene and its copolymers, polyurethane, polyamide, poly(vinyl chloride), polyacrylonitrile, or a polymeric liquid crystal resin. The most common image-receiving layer polymers are polyester, polycaprolactone and poly(vinyl chloride). Processes for forming such image-receiving layers are also described in detail in this patent; in most cases, the polymer(s) used to form the image-receiving layer are dissolved in an organic solvent, such as methyl ethyl ketone, dichloromethane or chloroform, and the resultant solution coated onto the polymer layer using conventional coating apparatus, and the solvent evaporated to form the image-receiving layer. However, if desired the image-receiving layer can be applied to the polymer layer by extrusion casting, or by slot, gravure or other known coating methods. [0024] The identification cards of the present invention may have only a single image-receiving layer, but is generally preferred that they have two image-receiving layers, one such layer being provided on each layer of polyester on the side thereof remote from the core layer. Typically, one or more second indicia intended for human reading may be printed on the image-receiving layer on the front side of the identification document, and one or more additional second indicia intended for machine reading (for example, bar codes) may be printed on the image-receiving layer on the back side. [0025] Following the printing of the second indicia on the image-receiving layer, a protective layer is affixed over at least the portion of the or each image-receiving layer carrying the second indicia; this protective layer serves to protect the relatively fragile image-receiving layer from damage, and also prevents bleeding of the thermal transfer dye from the image-receiving layer. Materials suitable for forming such protective layers are known to those skilled in the art of dye diffusion thermal transfer printing and any of the conventional materials may be used provided they have sufficient transparency and sufficient adhesion to the specific image-receiving layer with which they are in contact and block bleeding of dye from this layer. Typically, the protective layer will be a biaxially oriented polyester or other optically clear durable plastic film. [0026] The protective layer desirably provides additional security features for the identification card. For example, the protective layer may include a low cohesivity polymeric layer, an optically variable ink, an image printed in an ink which is readable in the infra-red or ultraviolet but is invisible in normal white light, an image printed in a fluorescent or phosphorescent ink, or any other available security feature which protects the document against tampering or counterfeiting, and which does not compromise the ability of the protective layer to protect the identification document against wear and the elements. [0027] In an alternate embodiment, the image-receiving layer may be formed from any material capable of receiving ink-jet printing. Many commercially available inkjet receiver coatings will suffice, however it is important that the inkjet receiver coating is only applied in the area where printing will occur, to ensure that the polyester layer will properly adhere to the core layer. The identification card may then be personalized with a common inkjet printer prior to addition of the polyester layers. In this embodiment the personalized information is printed between the core layer and the polyester layers, thus eliminating the need for an additional protective layer. [0028] FIG. 1 of the accompanying drawings shows a schematic cross-section through an embodiment of an identification card of the present invention. The document comprises a core layer 12 and a bottom layer 14 , both formed of an opaque white reflective polyolefin (preferably the aforementioned TESLIN® sheet). One side of the core layer and one side of the bottom sheet are printed with fixed indicia 16 . Sandwiched between the core layer 12 and the bottom layer 14 are an antenna 18 connected to an integrated circuit chip 20 . An alkyd resin spid 22 lies beneath the core layer 12 and the antenna 18 . An adhesive layer 24 (preferably KRTY) is applied to the bottom layer 14 on the side facing the core layer 12 . The bottom layer 14 and the core layer 12 are joined with an adhesive layer 26 (preferably TXP(3)). Recesses 28 are cut into the adhesive layer 26 to accommodate the integrated circuit chip 20 . [0029] The core layer 12 and bottom layer 14 are sandwiched between two polymer layers 30 formed from an amorphous or biaxially oriented polyester or other optically clear plastic such as polycarbonate. Each of these polymer layers 30 is fixedly secured to the core layer 12 and bottom layer 14 by an adhesive layer 32 . On the opposed side of each polymer layer 30 from the laminated core layer 12 and bottom layer 14 is provided an image-receiving layer 34 suited to accept a printed image or portrait or other variable indicia by dye diffusion thermal transfer methods. [0030] After the variable indicia have been printed on the image-receiving layers 34 , a biaxially oriented polyester or other optically clear durable plastic protective layer 36 is applied to protect the variable indicia and prevent bleeding of dye from the image-receiving layers 34 . The protective layer 36 may be provided with a low cohesivity layer, security ink or other security feature. [0031] FIG. 2 of the accompanying drawings shows a schematic cross-section through an alternate embodiment of an identification card of the present invention. The document, generally designated 10 , comprises a core layer 12 and a bottom layer 14 , both formed of an opaque white reflective polyolefin (preferably the aforementioned TESLIN® sheet). Opposed sides of the core layer and the bottom sheet are printed with fixed indicia 16 . Sandwiched between the core layer 12 and the bottom layer 14 is an antenna 18 connected to an integrated circuit chip 20 . An alkyd resin spid 22 lies beneath the core layer 12 and the antenna 18 . An adhesive layer 24 (preferably KRTY) is applied to the bottom layer 14 on the side facing the core layer 12 . The bottom layer 14 and the core layer 12 are joined with an adhesive layer 26 (preferably TXP(3)). Recesses 28 are cut into the adhesive layer 26 to accommodate the integrated circuit chip 20 . [0032] The laminated core layer 12 and bottom layer 14 is sandwiched between two polymer layers 30 formed from an amorphous or biaxially oriented polyester or other optically clear plastic such as polycarbonate. An inkjet receiver coating 38 is supplied between the core layer 12 and a polymer layer 30 . The inkjet receiver coating 38 may contain personalized data 40 Each of the polymer layers 30 is fixedly secured to the core layer 12 and bottom layer 14 by a layer 32 of adhesive. [0033] The following Examples are now given, though by way of illustration only, to show details of specific preferred reagents, conditions and techniques used to prepare identification cards of the present invention. EXAMPLE 1 [0034] Core layers of silica-filled polyolefin were prepared, preferably of the aforementioned TESLIN®, of 0.01″ thickness in the size of four A4 sheets (210 mm×297 mm×4 mm). The core layers were heated at 105° C. for approximately 30 minutes to pre-shrink the material. Alkyd resin spids, in a racetrack design, were then printed on the bottom side of the shrunken core layers, and background artwork was printed on a side of the core layers. Silver-epoxy antennae were then screen-printed onto the spidded areas of the sheets, and IC chips were then attached to the antennae. Because the core layers were heated repeatedly during this process, it is important that the polyloefin be pre-shrunk to avoid any shrinking problems during printing of the artwork or attachment of the electronic components. [0035] Bottom layers were prepared by pre-shrinking 10 mm thick silica-filled polyolefin sheet in the manner described above. Artwork was printed onto a side of the bottom layer. 1.5 mm of an adhesive, preferably KRTY, was applied to an opposed side of the bottom layers to adhere the IC chip to the bottom layer. [0036] The core layers and the bottom layers were joined by a free film of adhesive (7 mm of TXP (3)) cut into A 4 sized sheets. Holes were precut in the TXP(3) adhesive sheets to accommodate the IC chips. The core layers and bottom layers were then joined by the TXP(3) adhesive layer such that the antennae and chips were sandwiched between them, thus encasing and protecting the electronic components. The core layers and bottom layers were joined (up to 10 at a time) using a Tetrahedron press. Initially, the pressure used was very low (of less than approximately 400 psi) and the temperature was relatively high (approximately 290° F.) so that the TXP(3) adhesive layer was allowed to flow and so that the electronic components are not damaged. Pressure and temperature were then increased to approximately 3 ksi and 300° F. to bond the three layers together. The temperature was then lowered to approximately 170° F. while the pressure remained relatively high (approximately 2 ksi) so that the TXP(3) adhesive layer would solidify without altering the form of the pressed core layer. Pressure was then reduced and the press was opened, yielding a core layer/bottom layer laminate encasing the electronic components. [0037] This core layer/bottom layer was then laminated using a nip-roll lamination process. The top laminate material used was a 7/3 TXP (5)/KRTY onto which a dye diffusion thermal transfer receiver coating had been applied to the adhesive side. The bottom laminate was a 7/3 TXP (5)/KRTY layer. The resulting card was then imprinted with personal information on both the front and back using an Atlantek printer. Security features, such as UV sensitive inks or Polasecure®, can be added to the top surface of the card. After this, a 0.001″ thick bi-axial polyester laminate was applied to both sides of the identification card. EXAMPLE 2 [0038] The core layer/bottom layer was prepared as described in Example 1. For personalization, however, an inkjet receiver coating, preferably a Grace-Davision formulation, was patch-coated onto selective areas of the core layer opposite the bottom layer. It is important that the entire core layer was not coated with the receiver coating or the core would not properly adhere to the polyester laminate. Image and text were printed onto the receiving layer using a Canon® 8200 printer and pigment-based inks. The printed cores were then belt laminated on both sides using 7/3 TXP (0)/KRTY as both the top and bottom laminate. [0039] From the foregoing, it will be seen that the present invention provides an identification card which affords significant improvements in durability (by protecting the integrated circuit chip and antenna) and ease of manufacture as compared with the prior art identification cards and smart cards described above. It is to be understood that the above-described embodiments are merely illustrative of the present invention and represent a limited number of the possible specific embodiments that can provide applications of the principles of the invention. Numerous and varied other arrangements may be readily devised in accordance with these principles by those skilled in the art without departing from the spirit and scope of the invention as claimed.

An identification card is prepared by attaching an antenna and integrated circuit chip onto a core layer of polyolefin, attaching a bottom sheet to the core layer thus encasing the antenna and integrated circuit chip, providing an image-receiving layer on one or both outer surfaces of the resulting sandwich, and laminating a protective layer or layers over the image-receiving layer(s). The identification document displays improved durability, ease of manufacture and protection of the electronic components.

big_patent

FIELD OF THE INVENTION [0001] The present invention relates generally to the implementation of a memory. More specifically, the invention relates to the implementation of a queue, particularly a FIFO-type queue (First In First Out), in a memory. The solution in accordance with the invention is intended for use specifically in connection with functional memories. By a functional memory is understood a memory in which updates, such as additions, are carried out in such a way that first the path from the root of a tree-shaped structure to the point of updating is copied, and thereafter the update is made in the copied data (i.e., the update is not directly made to the existing data). Such an updating procedure is also termed “copy-on-write”. BACKGROUND OF THE INVENTION [0002] In overwrite memory environments, in which updates are not made in the copy but directly in the original data (overwrite), a FIFO queue is normally implemented by means of a double-ended list of the kind shown in FIG. 1. The list comprises nodes of three successive elements in a queue, three of such successive nodes being shown in the figure (references N(i−1), Ni and N(i+1)). The element on the first edge of each node has a pointer to the preceding node in the queue, the element on the opposite edge again has a pointer to the next node in the queue, and the middle element in the node has either the actual stored data record or a pointer to a record (the figure shows a pointer). [0003] However, such a typical way of implementing a FIFO queue is quite ineffective for example in connection with functional memories, since each update would result in copying of the entire queue. If, therefore, the queue has e.g. N nodes, all N nodes must be copied in connection with each update prior to performing the update. SUMMARY OF THE INVENTION [0004] It is an object of the present invention to accomplish an improvement to the above drawback by providing a novel way of establishing a queue, by means of which the memory can be implemented in such a way that the amount of required copying can be reduced in a functional structure as well. This objective is achieved with a method as defined in the independent claims. [0005] The idea of the invention is to implement and maintain a queue by means of a tree-shaped structure in which the nodes have a given maximum size and in which (1) additions of data units (to the queue) are directed in the tree-shaped data structure to the first non-full node, seen from below, on the first edge of the data structure and (2) deletions of data units (from the queue) are also directed to a leaf node on the edge of the tree, typically on the opposite edge. Furthermore, the idea is to implement the additions in such a way that the leaf nodes remain at the same hierarchy level of the tree-shaped data structure, which means that when such a non-full node is not present, new nodes are created to keep the leaf nodes at the same hierarchy level. The tree-shaped data structure will also be termed shortly a tree in the following. [0006] When the solution in accordance with the invention is used, each update to be made in the functional environment requires a time and space that are logarithmically dependent on the length of the queue, since only the path leading from the root to the point of updating must be copied from the structure. The length of this path increases logarithmically in relation to the length of the queue. (When a FIFO queue contains N nodes, log N nodes shall be copied, where the base number of the logarithm is dependent on the maximum size of the node.) [0007] Furthermore, in the solution in accordance with the invention the node to be updated is easy to access, since the search proceeds by following the edge of the tree until a leaf node is found. This leaf node provides the point of updating. [0008] In accordance with a preferred embodiment of the invention, the data structure also comprises a separate header node comprising three elements, each of which may be empty or contain a pointer, so that when one element contains a pointer it points to a separate node constituting the end of the queue, when a given second element contains a pointer it points to said tree-shaped structure that is maintained in the above-described manner, and when a given third element contains a pointer it points to a separate node constituting the beginning of the queue. In this structure, additions are made in such a way that the node constituting the end is always filled first, and only thereafter will an addition be made to the tree-shaped structure. Correspondingly, an entire leaf node at a time is always deleted from the tree-shaped structure, and said leaf node is made to be the node constituting the beginning of the queue, wherefrom deletions are made as long as said node has pointers or data units left. Thereafter, a deletion is again made from the tree. On account of such a solution, the tree need not be updated in connection with every addition or deletion. In this way, the updates are made faster than heretofore and require less memory space than previously. [0009] Since the queue in accordance with the invention is symmetrical, it can be inverted in constant time and constant space irrespective of the length of the queue. In accordance with another preferred additional embodiment of the invention, the header node makes use of an identifier indicating in each case which of said separate nodes constitutes the beginning and which constitutes the end of the queue. The identifier thus indicates which way the queue is interpreted in each case. The queue can be inverted by changing the value of the identifier, and the tree structure will be interpreted as a mirror image. BRIEF DESCRIPTION OF THE DRAWINGS [0010] In the following the invention and its preferred embodiments will be described in closer detail with reference to examples in accordance with the accompanying drawings, in which [0011] [0011]FIG. 1 illustrates a typical implementation of a FIFO queue, [0012] [0012]FIG. 2 a shows a tree-shaped data structure used in the implementation of a FIFO queue and the principle of updates made in a functional memory, [0013] [0013]FIG. 2 b illustrates the generic structure of a discrete node in the tree-shaped data structure used to implement the FIFO queue, [0014] [0014]FIGS. 3 a . . . 3 h illustrate making of additions to a FIFO queue when the memory is implemented in accordance with the basic embodiment of the invention, [0015] [0015]FIGS. 4 a . . . 4 g illustrate making of deletions from a FIFO queue when the memory is implemented in accordance with the basic embodiment of the invention, [0016] [0016]FIGS. 5 a . . . 5 h illustrate making of additions to a FIFO queue when the memory is implemented in accordance with a first preferred embodiment of the invention, [0017] [0017]FIGS. 6 a . . . 6 h illustrate making of deletions from a FIFO queue when the memory is implemented in accordance with the first preferred embodiment of the invention, [0018] [0018]FIG. 7 illustrates a preferred embodiment for a header node used in the structure, and [0019] [0019]FIG. 8 shows a block diagram of a memory arrangement in accordance with the invention. DETAILED DESCRIPTION OF THE INVENTION [0020] [0020]FIG. 2 a illustrates a tree-shaped data structure used to implement a FIFO queue in accordance with the invention and the principle of updating used in a functional memory environment. The figure illustrates a FIFO queue in an initial situation in which the queue comprises data records 1 . . . 5 and thereafter in a situation in which a further record 6 has been added to the queue. [0021] The data structure in accordance with the invention, by means of which the FIFO queue is established, comprises nodes and pointers contained therein. FIG. 2 b illustrates the generic structure of a node. The node comprises a field TF indicating the node type and an element table having one or more elements NE. Each element in the node has a pointer pointing downward in the structure. In accordance with the invention, a given upper limit has been set for the number of elements (i.e., the size of the node). Hence, the nodes are data structures comprising pointers whose number in the node is smaller than or equal to said upper limit. In addition to the pointers and the type field, also other information may be stored in the node, as will be set forth hereinafter. At this stage, however, the other information is not essential to the invention. [0022] The node at the highest level of the tree is called the root node, and all nodes at equal distance from the root node (measured by the number of pointers in between) are at the same (hierarchy) level. The nodes to which there are pointers from a given node are said to be child nodes of said node, and correspondingly said given node is said to be the parent node of these nodes. The tree-shaped data structure in accordance with the invention can have two kinds of nodes: internal nodes (N 1 , N 2 and N 3 ) and leaf nodes (N 4 , N 5 and N 6 ). Internal nodes are nodes wherefrom there are pointers either to another internal node or to a leaf node. Leaf nodes, on the other hand, are nodes at the lowest level of the tree, wherefrom only records are pointed to. Thus the leaf nodes do not contain pointers to other leaf nodes or internal nodes. Instead of pointers, the leaf nodes can also contain actual records, particularly when all records to be stored in the queue are of equal size. Whilst it was stated above that each element in a node has a pointer pointing downward in the structure, the leaf nodes make an exception to this if the records are stored in the leaf nodes. [0023] In FIG. 2 a, the rectangle denoted with broken line A illustrates a tree-shaped structure in an initial situation in which the structure comprises nodes N 1 . . . N 6 , in which case records 1 . . . 5 in the FIFO queue are either in leaf nodes N 4 . . . N 6 or leaf nodes N 4 . . . N 6 contain pointers to records 1 . . . 5 . When record 6 is added to this FIFO queue, an addition is made to node N 4 , wherein in the functional structure the path from the root node (N 1 ) to the point of updating (node N 4 ) is first copied. The copied path is denoted with reference P and the copied nodes with references N 1 ′, N 2 ′ and N 4 ′. Thereafter record 6 is added to the copy (node N 4 ′) and pointers are set to point to the previous data. In this case, the pointer (PO) of the second element of node N 1 ′ is set to point to node N 3 . After the updating, the memory thus stores a data structure represented by a polygon denoted by reference B. The nodes that are not pointed to are collected by known garbage collection methods. [0024] In the invention, a balanced tree structure is used to implement a queue. This tree meets the following two conditions: [0025] 1. all leaf nodes of the tree are at the same level. [0026] 2. All internal nodes of the tree are full, except for the nodes on the left or right edge of the tree, which are not necessarily full. [0027] The first condition is called the balance condition and the second condition the fill condition. In addition, a maximum size is set for the nodes of the tree, the nodes may e.g. be permitted only five child nodes. In the following, the maintenance of the FIFO queue in accordance with the invention will be described in detail. [0028] [0028]FIGS. 3 a . . . 3 h illustrate a procedure in which records 1 . . . 8 are added to an initially empty tree structure (i.e., a FIFO queue) one record at a time. In this example, as in all the following examples, the following presumptions and simplifications have been made (for straightforwardness and clarity): [0029] a node may have a maximum of two pointers only, [0030] the records (i.e., their numbers) are drawn within the leaf nodes, even though each leaf node typically has a pointer to said record. It is presumed in the explication of the example that the leaf nodes have pointers to records, even though the leaf nodes may also contain records. [0031] the copying to be carried out in the functional structure is not shown in order to more clearly highlight the principle of the invention. Thus, the same reference is used for the copy of a node and the corresponding original node. [0032] In the initial situation, the queue is empty, and when an addition is made to the queue, single-pointer internal node (N 1 ) pointing to the added record is formed (FIG. 3 a ). When another record is added to the queue, the node is made into a two-pointer node containing pointers to both the first and the second record (FIG. 3 b ). When a third record is added, a new two-pointer internal node (N 2 ) is created, the right-hand pointer of which points to the old internal node and the left-hand pointer of which points to a new leaf node (N 3 ) having as a single child the new added record (FIG. 3 c ). When a fourth record is added, the addition is made (FIG. 3 d ) to the single-child node (N 3 ) on the left-hand edge of the tree. In connection with the addition of a fifth record, a new two-pointer root node (N 4 ) is again created, the right-hand element of which is set to point to the old root node and the left-hand element of which is set to point through two new single-pointer nodes (N 5 and N 6 ) to the added record (FIG. 3 e ). These new nodes are needed in order for the balance condition of the tree to be in force, that is, in order that all leaves of the tree may be at the same level. [0033] The addition of the next record (record six) is again made to the single-child leaf node N 6 on the left-hand edge of the tree (FIG. 3 f ). Thereafter, in connection with the addition of the next record, the node (N 5 ) on the left-hand edge of the tree next to the leaf node is filled, and the new pointer of said node is set to point to the added record (seven) through a new (single-child) leaf node N 7 . The last record (eight) is added by adding another pointer to this leaf node, pointing to the added record. [0034] As stated previously, the copying carried out in the structure has not been illustrated at all for simplicity and clarity, but the figures only show the result of each adding step. In practice, however, copying is carried out in each adding step, and the update is made in the copy. Thus, for example record two is added in such a way that a copy is made of leaf node N 1 and the record pointer is added to this copy. Correspondingly, for example in connection with the addition of record five, the content of the two-pointer node (N 2 ) that is the root node is copied into the correct location before the addition and the update is made in the copy (nodes N 4 . . . N 6 with their pointers are added). FIG. 2 a shows what kind of copying takes place for example in connection with the addition of record 6 (cf. FIGS. 3 e and 3 f ). Since such a functional updating policy is known as such and does not relate to the actual inventive idea, it will not be described in detail in this context. [0035] Deletion from the tree takes place in reverse order, that is, the right-most record is always deleted from the tree. FIGS. 4 a . . . 4 g illustrate a procedure in which all the records referred to above are deleted one at a time from the FIFO queue constituted by the tree structure of FIG. 3 h which contains eight records. In the initial situation, the rightmost record (i.e., record one) of the tree is first searched therefrom, the relevant node is copied in such a way that only record two remains therein, and the path from the point of updating to the root is copied. The result is a tree as shown in FIG. 4 a. Similarly, record two is deleted, which gives the situation shown in FIG. 4 b, and record three, which gives the situation shown in FIG. 4 c. If during deletion an internal node becomes empty, the deletion also proceeds to the parent node of said node. If it is found in that connection that the root node contains only one pointer, the root node is deleted and the new root will become the node which this single pointer points to. When record four is deleted, it is found that internal node N 2 becomes empty, as a result of which the deletion proceeds to the root node (N 4 ). Since the root node contains only one pointer after this, the root node is deleted and node N 5 will be the new root. This gives the situation of FIG. 4 d. Thereafter the deletions shown in the figures proceed in the manner described above, i.e. the rightmost record is always deleted from the tree and the root node is deleted when it contains only one pointer. [0036] The copying to be carried out has not been described in connection with deletion either. The copying is carried out in the known manner in such a way that from the leaf node wherefrom the deletion is made, only the remaining part is copied, and in addition the path from the root to the point of updating. The pointers of the copied nodes are set to point to the nodes that were not copied. [0037] As will be seen from the above explication, in a FIFO queue in accordance with the invention [0038] all leaf nodes in the tree are always at the same level (the lowest level if the records are not taken into account), [0039] all nodes in the tree are full, except for the nodes on the edges of the tree, and [0040] nodes are filled upwards. This means that in the first place, a non-full leaf node on the edge of the tree is filled. If such a leaf node is not found, the next step is to attempt to fill a non-full internal node on the edge next to a leaf node. [0041] The additions and deletions can also be expressed in such a way that when an addition is made to the tree, the new record is made to be a leaf in the tree, which is obtained first in a preorder, and when a deletion is made from the tree the deletion is directed to the record that is obtained first in a postorder. [0042] The above-stated structure can also be implemented as a mirror image, in which case the node added last is obtained first in a postorder and the one to be deleted next is obtained first in a preorder. This means that the additions are made on the right-hand edge and deletions on the left-hand edge of the tree (i.e., contrary to the above). [0043] The above is an explanation of the basic embodiment of the invention, in which a FIFO queue is implemented merely by means of a tree-shaped data structure. In accordance with a first preferred embodiment of the invention, a three-element node, which in this context is called a header node, is added to the above-described data structure. One child of this header node forms the leaf node at the end (or pointing to the end) of the FIFO queue, the second child contains a tree of the kind described above, forming the middle part of the FIFO queue, and the third child forms the leaf node at the beginning (or pointing to the beginning) of the queue (provided that such a child exists). The separate nodes of the beginning and the end are called leaf nodes in this connection, since a filled node of the end is added as a leaf node to the tree and a leaf node that is deleted from the tree is made to be the node of the beginning. [0044] [0044]FIGS. 5 a . . . 5 h illustrate a procedure in which records 1 . . . 8 are added to an initially empty queue one record at a time. The header node is denoted with reference HN, the leftmost element in the header node, which in this case points to a (leaf node at the end of the queue, is denoted with the reference LE, and the rightmost element in the header node., which in this case points to a (leaf) node at the beginning of the queue, is denoted with reference RE. [0045] When a record is added to the end of the queue, a copy is made of the leaf node of the end and the record pointer is added to the copy (FIGS. 5 a and 5 b ). If, however, the leaf node of the end is already full (FIGS. 5 d and 5 f ), said leaf node is transferred to the tree in the header node (pointed to from the middlemost element in the header node). Thereafter a new leaf node for the end is created, in which said record is stored (FIGS. 5 e and 5 g ). The addition of the leaf node to the tree is made in the above-described manner. The addition thus otherwise follows the above principles, but an entire leaf node is added to the tree, not only one record at a time. Hence, all leaf nodes in the tree are at the same level. The node pointed to from the leftmost element of the header node is thus always filled, whereafter the entire leaf node is added to the tree. [0046] When a deletion is made from the beginning of the queue, it is first studied whether the beginning of the queue is empty (that is, whether the right-most element in the header node has a pointer). If the beginning is not empty, the rightmost record is deleted from the leaf node of the beginning. If, on the other hand, the beginning is empty, the rightmost leaf node is searched from the tree representing the middle part of the queue. This leaf node is deleted from the tree in the manner described above, except that an entire leaf node is deleted from the tree at a time, not only one record at a time as in the basic embodiment described above. This deleted leaf node is made to be the leaf node of the beginning of the queue, and thus the beginning is no longer empty. If also the tree is empty, the leaf node of the end is made to be the leaf node of the beginning. If also the end is empty, the entire queue is empty. Deletion from the beginning of the queue is made by copying the leaf node of the beginning in such a way that its last record is deleted in connection with the copying. [0047] [0047]FIGS. 6 a . . . 6 h illustrate a procedure in which the records 1 . . . 8 added above are deleted from the queue one record at a time. The initial situation is shown in FIG. 5 h. In the initial situation, the beginning of the queue is empty, and thus the rightmost leaf node is searched from the tree, said node being deleted from the tree and the deleted leaf node being made into the leaf node of the beginning of the queue. This gives the situation of FIG. 6 a. The next deletion is made from the leaf node of the beginning, as a result of which the beginning becomes empty. Thereafter the rightmost record in the tree (record three) is again deleted. Since in that case only a single pointer remains in the root node of the tree, said root node is deleted. Also the new root node has only one pointer, wherefore it is deleted too. This gives the situation of FIG. 6 c, in which the next record to be deleted is record four. When this record is deleted, the beginning of the queue is again empty (FIG. 6 d ), and thus in connection with the next deletion the leaf node pointing to record six is moved to the beginning of the queue, which makes the tree empty (FIG. 6 e ). When record six has been deleted, also the beginning is empty (FIG. 6 f ), and thus in connection with the next deletion the leaf node of the end is made to be the leaf node of the beginning (FIG. 6 g ). When also the end is empty (in addition to the fact that the beginning and the tree are empty), the entire queue is empty. [0048] For the header node, the updating policy of the functional structure means that in connection with each addition, the header node and the leaf node of the end of the queue are copied. From this copy, a new pointer is set to the tree and to the old beginning (which thus need not be copied). Correspondingly, in connection with deletions the header node and the remaining portion of the leaf node of the beginning of the queue are copied and a new pointer is set from the copy to the tree and the old end. [0049] By adding a header node to the memory structure, the updates will be made faster and less space-consuming than heretofore, since for the header node the additions require a (constant) time independent of the length of the queue. For example, if the maximum size of the node is five, only a fifth of the additions is made to the tree, and thus four fifths of the additions require a constant time and a fifth a time logarithmically dependent on the length of the queue. [0050] In accordance with another preferred embodiment of the invention, a bit is added to the header node, indicating which edge of the header node constitutes the end and which the beginning of the FIFO queue. In other words, the value of the bit indicates whether the queue is inverted or not. If the bit has for example the value one, the leaf node pointed to from the leftmost element LE of the header node is construed as the end of the queue and the leaf node pointed to from the rightmost element RE as the beginning of the queue, respectively. If the value of the bit changes to be reverse, the beginning and end are construed in the reverse order and, furthermore, the tree representing the middle part of the queue is construed as a mirror image in relation to the previous interpretation. FIG. 7 illustrates the generic (logical) structure of the header node. In addition to the inversion bit IB, the node comprises the above-stated type field TF, indicating that a header node is concerned. In addition, the node has the above-stated three elements, each of which may be empty or contain a pointer. The order of these elements can also vary in such a way that the beginning, middle, or end of the queue can be pointed to from any element. Thus, the middle part is not necessarily pointed to from the element in the middle and the beginning or end from an element on the edge. [0051] Since copying the header node and making an update in the copy and updating the above-stated bit to an inverse value of the original value is sufficient for inversion of the queue, the queue can be inverted in constant time and space. Since the structure is also fully symmetrical, the queue can be used as a double-ended queue, that is, additions can also be made to the beginning and deletions can be made from the end of the queue (FIFO or LIFO principle). For a double-ended queue, the shorter term deque is also used. [0052] The bit indicating the direction of the queue can also be used in the basic embodiment of the invention in which there is no header node. In such a case, the bit can be added to the individual nodes, and thus the bit indicates which edge of the tree is the beginning of the queue and which the end in that part of the tree which is beneath said node. [0053] [0053]FIG. 8 illustrates a block diagram of a memory arrangement in accordance with the invention, implementing a memory provided with a header node. The memory arrangement comprises an actual memory MEM, in which the above-described tree structure with its records is stored, a first intermediate register IR_A in which the leaf node of the end (or beginning) of the queue is stored, a second intermediate register IR_B in which the leaf node of the beginning (or end) of the queue is stored, and control logic CL maintaining the queue (making additions of records to the queue and deletions of records from the queue). [0054] For the control logic, the memory arrangement further comprises a flag register FR in which the value of the inversion bit is maintained. Furthermore, the memory arrangement comprises an input register IR through which the input of the record pointers takes place and an output register OR through which the record pointers are read out. [0055] As normally in systems of this kind, the records are stored in advance in the memory (MEM), and in this record set a queue is maintained by means of pointers pointing to the records. [0056] When a record pointer is supplied to the input register, the control logic adds it to the leaf node in the first intermediate register IR_A. If the first intermediate register is full, however, the control logic first stores the content of the register in the tree stored in the memory MEM. This takes place in such a way that the control logic follows the edge of the tree and copies the path from the root to the point of updating and makes the update in the copy. Thereafter the control logic adds a pointer to the intermediate register IR_A. [0057] When records are deleted from the queue, the control logic reads the content of the second intermediate register IR_B and deletes the record closest to the edge therefrom, if the intermediate register is not empty. If the intermediate register is empty, the control logic retrieves from memory, following the edge of the tree, a leaf node and transfers its remaining part to the second intermediate register. At the same time, the control logic updates the tree in the manner described above. [0058] Even though the invention has been explained in the above with reference to examples in accordance with the accompanying drawings, it is obvious that the invention is not to be so restricted, but it can be modified within the scope of the inventive idea disclosed in the appended claims. For example, the maximum size of the nodes is not necessarily fixed, but it can e.g. follow a pattern, for example so that at each level of the tree the nodes have their level-specific maximum size. Since the actual records can be stored separately and the tree only serves for forming a queue therefrom and maintaining the queue, the records can be located in a memory area or memory block separate from the tree.

The invention relates to a method for implementing a queue, particularly a FIFO queue, in a memory (MEM) and to a memory arrangement. In order to enable reducing the amount of copying particularly in a functional environment, at least part of the queue is formed with a tree-shaped data structure (A, B) known per se, having nodes at several different hierarchy levels, wherein an individual node can be (i) an internal node (N 1 -N 3 ) containing at least one pointer pointing to a node lower in the tree-shaped hierarchy or (ii) a leaf node (N 4 -N 6 ) containing at least one pointer to data unit ( 1 . . . 6 ) stored in the memory or at least one data unit. A given maximum number of pointers that an individual node can contain is defined for the nodes. The additions to be made to said part are directed in the tree-shaped data structure to the first non-full node (N 4 ), seen from below, on a predetermined first edge of the data structure and they are further implemented in such a way that the leaf nodes remain at the same hierarchy level of the tree-shaped data structure, wherein when a non-full node is not present, new nodes are created to maintain the leaf nodes at the same hierarchy level. The deletions to be made from said part are typically directed to the leaf node on the opposite edge of the tree.

big_patent

BACKGROUND OF THE INVENTION The present invention relates to electrically programmable random access memory (EPROM) devices, and more particularly to embedded EPROM devices manufactured by existing integrated circuit (IC) technologies. Current art EPROM devices are manufactured by special technologies that are optimized only for stand-along EPROM products. It is not practical to put other types of integrated circuits, such as DRAM or high performance logic circuits, on the same wafer with current art EPROM devices. On the other hand, it is strongly desirable to have programmable devices for DRAM or logic circuits. DRAM devices are typically high density devices; each individual DRAM device contains millions or even billions of memory cells. It is very difficult to manufacture such a large device without any local failures. DRAM devices are therefore equipped with programmable redundancy circuits. The redundancy circuits repair partial failures on individual devices. Such redundancy circuits improve DRAM yield dramatically and therefore reduce the cost of DRAM products significantly. The redundancy circuits must be programmable to fix failures at different locations. Ideally, we would like to program those redundancy circuits using EPROM. When the device can be programmed electrically, the required testing costs can be reduced significantly. The problem is that no current art EPROM devices can be manufactured using current art DRAM manufacture technologies. Current art DRAM redundancy circuits usually use fuses to support its programmable functions. Those fuses occupy relatively large areas. Sophisticated wafer level testing equipment equipped with LASER is required to burn those fuses in order to configure the redundant circuits. The process is destructive and cumbersome. It is therefore strongly desirable to use EPROM devices, instead of fuses, to support DRAM redundancy circuits. Besides redundancy circuits, EPROM devices are very useful for other applications. For example, we can implement programmable firmware on logic circuits so that the same product can be programmed to support different applications. Each individual product can have its own identification (ID) number for security purpose if it is equipped with EPROM devices. The problem is, again, current art EPROM devices can not be manufactured by standard logic technologies. Currently, special embedded EPROM technologies are available to build conventional EPROM devices and logic circuits on the same wafer. Such special technologies require many more manufacturing steps than standard logic technologies so that the cost is significantly higher. Another major problem is that conventional EPROM devices require high voltages to support programming and erase operations. The requirement for high voltages further complicates the manufacture technology. It is therefore strongly desirable to have EPROM devices that can be manufactured by standard logic technologies. SUMMARY OF THE INVENTION The primary objective of this invention is, therefore, to providing practical methods to build embedded EPROM devices using existing IC manufacture technologies. One objective of the present invention is to provide EPROM device for DRAM redundancy circuits using existing DRAM technology. Another objective of the present invention is to provide EPROM devices manufactured by standard logic technologies. It is also desirable that such devices do not require high voltages for its operations. These and other objectives are accomplished by novel device structures that utilize existing circuit elements to build EPROM devices without complicating existing manufacture technologies. For example, DRAM storage capacitors are used as the coupling capacitors to build floating gate EPROM devices. Another example is to utilize transistor properties changed under stress conditions to support EPROM operations. While the novel features of the invention are set forth with particularly in the appended claims, the invention, both as to organization and content, will be better understood and appreciated, along with other objects and features thereof, from the following detailed descriptions taken in conjunction with the drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is the cross section diagram for a current art DRAM memory cell; FIGS. 2 ( a-d ) are cross section diagrams illustrating the manufacture procedures for current art DRAM; FIGS. 3 ( a-c ) are cross section diagrams illustrating the manufacture procedures for an EPROM device of the present invention; FIG. 4 ( a ) is the schematic diagram for the DRAM memory cells in FIG. 1; FIG. 4 ( a ) is the schematic diagram for the EPROM memory cells in FIG. 3 ( c ). FIG. 5 shows the current-voltage (I-V) relationship for a metal-oxide-silicon (MOS) transistor before and after hot electron stress; and FIGS. 6 ( a-d ) are the symbolic block diagram of the supporting circuit for stress EPROM devices of the present invention. DETAILED DESCRIPTION OF THE INVENTION The physical structure of a DRAM memory device is illustrated by the simplified cross-section diagram in FIG. 1 . Each DRAM memory cell ( 101 ) contains one select transistor ( 103 ) and one storage capacitor ( 107 ). The gate ( 105 ) of the select transistor is connected to memory word line (WL). This gate ( 105 ) is typically made of polycrystalline silicon (poly) thin film. The gate is separated from the substrate by a thin film gate oxide, but the gate oxide is too thin to be shown in the diagram. The source ( 106 ) of the select transistor is connected to the bottom electrode ( 108 ) of the storage capacitor ( 107 ). This storage capacitor ( 107 ) contains two electrodes. The top electrode ( 109 ) is usually called the “plate” electrode in current art DRAM technology. The plate is usually shared by a plural of memory cells, and it is usually connected to a stable voltage source. The bottom electrode ( 108 ) of the storage capacitor ( 107 ) is unique for each memory cell, and it is used to store data. There is a thin insulating layer between the two electrodes of the storage capacitor, which is too thin to be shown in our figures. A contact plug ( 102 ) is usually used to connect the bottom electrode ( 108 ) of the storage capacitor to the source ( 106 ) of the select transistor, which is separated from the source of nearby transistor (not shown) by filed oxide ( 112 ). The drain ( 104 ) of the select transistor is connected to the memory bit line (not shown). To reduce bit line loading, the drain ( 104 ) electrode is typically shared by the select transistor ( 113 ) of a nearby memory cell. In FIG. 1, this drain ( 104 ) area is represented by dashed lines because it is usually not on the same cross-section plan as the storage capacitor ( 107 ). The manufacture procedures for the DRAM storage capacitor ( 107 ) are illustrated by the simplified cross-section diagrams in FIGS. 2 ( a-d ). FIG. 2 ( a ) shows the structure just before the beginning of the storage capacitor manufacture procedures. At this time, the select transistor ( 103 ) is fully manufactured, while the location for the storage capacitor is covered with insulator layers ( 201 ). The next step is to dig a deep DRAM contact hole ( 221 ) through the insulator ( 201 ) to the silicon substrate at the source ( 106 ) of the select transistor ( 103 ), as illustrated by the cross section diagram in FIG. 2 ( b ). Plasma etching is usually needed for this manufacture step. Typically, a plug ( 211 ) is placed into the bottom of the contact hole ( 221 ) before the bottom electrode ( 223 ) of the storage capacitor is formed around the contact hole ( 221 ) as illustrated by FIG. 2 ( c ). The top electrode ( 231 ) of the storage capacitor and the insulator between those two electrodes are formed in the contact hole ( 221 ) by a series of complex manufacture procedures, and the resulting structures are illustrated in FIG. 2 ( d ). The storage capacitor manufacture processes are very complex, and they can be different for technologies developed by different companies. For example, the contact plugs ( 211 ) usually are manufactured by separated processing steps. We do not intend to cover details of those manufacture procedures because the present invention is not dependent on such manufacture details. The manufacture procedures for an EPROM memory cell of the present invention are illustrated by the cross section diagrams in FIGS. 3 ( a-c ). FIG. 3 ( a ) shows the structure just before the beginning of the EPROM coupling capacitor is manufactured. At this time, the EPROM transistor ( 303 ) is fully manufactured, and its structure is very similar to the structure shown in FIG. 2 ( a ) except that the cross-section is taken away from the transistor at a nearby field oxide layer ( 312 ). The source ( 306 ) and drain ( 304 ) of the EPROM transistor ( 303 ) are represented by dashed lines because they are typically not on the same cross-section plan as the couple capacitor. The area on tope of those transistors is covered with insulator layers ( 315 ). The gate ( 305 ) of this EPROM transistor ( 303 ) is not connected to a word line; it is isolated from other EPROM memory cells to be served as the floating gate of the EPROM memory cell. The next step is to dig an EPROM contact hole ( 321 ) as illustrated by FIG. 3 ( b ). The EPROM contact holes ( 321 ) and the DRAM contact holes ( 211 ) are manufactured simultaneously with identical manufacture procedures. The difference is that an EPROM contact hole ( 321 ) is placed on top of the poly gate ( 305 ) electrode instead of the source ( 306 ) of the EPROM select transistor ( 303 ). The physical structure of an EPROM contact hole ( 321 ) is nearly identical to a DRAM contact hole ( 221 ). The floating gate ( 305 ) is made of polycrystalline silicon thin film that is of similar etching rate as the silicon substrate at the source ( 106 ) of a DRAM select transistor ( 103 ). It is therefore possible to manufactured both the DRAM contact holes ( 221 ) and the EPROM contact holes ( 321 ) simultaneously while using identical etching procedures. After the EPROM contact holes ( 321 ) are opened, coupling capacitors ( 307 ) that has nearly identical structures as the DRAM storage capacitors ( 107 ) are manufactured at the locations of EPROM contact holes ( 321 ). The EPROM coupling capacitors ( 307 ) and the DRAM storage capacitors ( 107 ) are manufactured with identical procedures simultaneously. The cross section diagram in FIG. 3 ( c ) illustrated the final structures of a DRAM based EPROM ( 301 ) memory cell of the present invention. The top electrode ( 309 ) of the coupling capacitor ( 307 ) serves as the control gate (CG) of the EPROM memory cell. This control gate is manufactured with identical procedures and identical materials as the plate electrode ( 109 ) of the DRAM memory cell. The bottom electrode ( 308 ) of the coupling capacitor ( 307 ) is connected to the gate ( 305 ) of the EPROM select transistor ( 303 ), and serves as the floating gate (FG) of the EPROM memory cell ( 301 ). The drain ( 304 ) of the EPROM transistor ( 303 ) is connected to ERPROM bit lines (EBL). FIGS. 4 ( a, b ) are schematic diagrams showing the connections of the above DRAM and EPROM devices. Each DRAM memory cell ( 401 ) contains one select transistor ( 403 ) and one storage capacitor ( 407 ) as shown in FIG. 4 ( a ). The gate of the select transistor ( 403 ) is connected to word line (WL), its drain is connected to bit line (BL), and its source is connected to one terminal of its storage capacitor; the other terminal of the storage capacitor is connected to the plate electrode (PL). Each EPROM memory cell ( 411 ) contains one transistor ( 413 ) and one coupling capacitor ( 417 ). The drain of the EPROM transistor is connected to bit line (EBL), its source is connected to ground, and its gate is a floating gate (FG) connected to one electrode of the coupling capacitor; the other terminal of the coupling capacitor is connected to the control gate (CG). For an EPROM device of the present invention, the EPROM coupling capacitor ( 417 ) is manufactured in the same way as the DRAM storage capacitor ( 407 ). For most cases, the EPROM transistor ( 413 ) is also manufactured in the same way as the DRAM select transistor ( 403 ). It is therefore possible to have both DRAM and EPROM devices on the same wafer without adding cost to the manufacture procedures. The operation principles of the above EPROM memory cell of the present invention are the same as that of prior art EPROM memory cells. During a programming operation, the source ( 306 ) of the EPROM transistor ( 303 ) is connected to ground, the control gate (CG) is connected to a first voltage, and the drain ( 304 ) is connected to a second voltage. Electrons are injected into the floating gate (FG) of the EPROM cell by hot electron injection mechanism. Another method to program the EPROM cell is to apply a high positive voltage to the control gate (CG) so that electrons are injected into the floating gate (FG) by tunneling mechanism. To erase the EPROM cell, a high positive voltage is applied on the drain ( 304 ) and/or the source ( 306 ) of the EPROM transistor ( 303 ) while the control gate (CG) is connected to ground. Electrons are pulled out of the floating gate (FG) by tunneling mechanism during such erase operation. Another way to erase the cell is to apply ultra violet (UV) light to the EPROM memory cells so that electrons can leak out of the floating gate (FG). During a read operation, a voltage is applied on the control gate (CG), and the source ( 306 ) is connected to ground. External sense amplifiers (not shown) detects the current flowing out of the drain ( 304 ) into the EPROM bit line (EBL) to determine the data stored in the EPROM cell. While specific embodiments of the invention have been illustrated and described herein, it is realized that other modifications and changes will occur to those skilled in the art. It should be understood that the above particular examples are for demonstration only and are not intended as limitation on the present invention. Near every semiconductor manufacturer has specific methods in building the storage capacitors for DRAM memory cells. Key element of the above EPROM device of the present invention is to use DRAM storage capacitor as the coupling capacitor of EPROM memory cell. An EPROM device of the present invention utilizes the same manufacture procedures as the DRAM manufacturing procedures. Therefore, its detailed structures will vary as the details for the DRAM memory cell vary while the fictions of the EPROM devices of the present invention are independent of those detailed variations. The scope of the present invention should not be limited by detailed structures of its coupling capacitors. Other modifications to the structures of the EPROM devices of the present invention will also become obvious upon disclosure of the present invention. The above EPROM devices of the present invention have the following advantages: The major advantage is the capability to manufacture EPROM devices using existing DRAM manufacture technologies. It is therefore possible to have EPROM memory devices and DRAM memory devices on the same wafer without introducing additional manufacture cost. The coupling capacitors ( 417 ) of the EPROM devices of the present invention are by far larger than those of current art EPROM memory devices. Since the capacitance of a DRAM storage capacitor is typically more than 20 times higher than the capacitance of a transistor of equivalent area, the gate coupling ratio (GCR) of an EPROM device of the present invention is almost always higher than 0.95. The GCR for a current art EPROM device is typically around 0.5. That means the operation voltages needed to support the EPROM devices of the present invention can be reduced by nearly 50%. The programming and erase voltages requires to support EPROM devices of the present invention is therefore by far lower than that of current art EPROM memory devices. Lowering the supporting voltages dramatically simplifies the requirements on supporting circuits. The most obvious application of the present invention is to build programmable redundancy circuits on DRAM devices. Current art DRAM devices use fuses to program its on-chip redundancy circuits. That repair mechanism is destructive, and the fuses occupy large areas. The programming method also requires sophisticated wafer level tester that increases testing costs. When a repair circuit uses EPROM devices of the present invention, it can be re-programmed multiple times using simple electrical procedures. The repair also can be done in the field in case a device is damaged after installation. The repair circuits will have much smaller area while operating at much higher performance. Comparing to current art EPROM devices, one potential disadvantage of the above EPROM devices of the present invention is the durability of the gate oxide. Current art EPROM devices use special treatments on the gate oxide so that they can tolerate more than 100,000 program-erase (PE) cycles. When the EPROM devices of the present invention uses the same gate oxide as DRAM transistors, the gate oxide may not be able to tolerate such a large number of PE cycles. That is usually not a problem because most applications do not require many PE cycles. For applications that require high PE cycles, we need to use the gate oxide for conventional EPROM while we still can use DRAM storage capacitor as the EPROM gate coupling capacitor. In this way, we need to pay additional complexity in manufacturing two types of gate oxides. The resulting increase in price is still by far less than the condition to make DRAM and EPROM separately. Current art EPROM devices and the above EPROM devices of the present invention store data by putting electrical charges into floating gates (FG). Another way to build embedded EPROM device using existing manufacture technologies is to build EPROM devices without using floating gate devices. Such EPROM devices of the present invention use the damages caused by electrical stresses on common transistors. By comparing the electrical properties of transistors with different levels of damages, we are able to build novel EPROM devices that are extremely convenient for embedded applications. For example, we can utilize the hot carrier effects to build EPROM devices using common transistors. When an MOS transistor is operating at high drain-to-source voltage (Vds) while the gate-to-source voltage (Vgs) is slightly higher than its threshold voltage (Vt), there is a strong electrical field build up near its drain area. Such operation conditions are called “hot carrier stress” conditions. Under this stress condition, high energy electrons or holes (called hot carriers) generated by the strong electrical field cause damages to the transistor. The damages, called hot carrier effects, cause changes in transistor electrical properties. Typically, the threshold voltage (Vt) of an n-channel transistor increases after it is damaged by hot carrier effect as illustrated in FIG. 5 . The drain to source current under the same bias voltages is also lower after hot carrier damages. On the other words, the current driving capability of n-channel transistors decrease by hot carrier effects. P-channel transistors usually behave in the opposite way; their current driving capabilities increase after hot carrier stress. The damaging rate of hot carrier effect is significant only when the transistor is under hot carrier stress conditions. At other conditions the hot carrier damage rate is negligible. For example, when Vgs is much higher than Vt or when Vgs is lower than Vt, the transistor won't have a high electrical field near its drain so that there would be no hot carrier damage. Similarly, when Vds is small, the hot carrier effect is negligible. The knowledge allow us to operate a transistor under conditions that will not cause hot carrier damages. Another type of well-known transistor damage is the gate voltage (Vg) stress damage. Put a high voltage on the gate of a transistor, and permanent damages can be done to the transistor. For most n-channel transistors, Vg stress results in reduced current driving capability. The hot carrier effect and the Vg stress effect are well-known to the IC industry. They are usually major limiting factors for the development of new IC technologies. Special cares are taken to improve the tolerance in those effects. Special structures such as the lightly doped drain (LDD) structures are implemented to improve tolerances in hot carrier effects. These effects are therefore always fully studied and well-documented for all IC technologies. The hot carrier damages and Vg stress damages are permanent. Once a transistor is damaged, the effects remain for its lifetime. Under certain conditions (for example, thermal annealing) a damaged transistor can partially recover, but the damages can never fully recover. It is therefore possible to use these effects to store data and to build EPROM devices using common transistors. These types of EPROM devices of the present invention are named “stress effect programmable read only memory” (SEPROM) devices by the present inventor. Other types of active devices, such as bipolar transistors or diodes, also experience changes in properties after different types of electrical stresses. We can build SEPROM devices using bipolar transistors or diodes as building blocks following the same principles. FIG. 6 ( a ) is a symbolic block diagram illustrating the general operations of SEPROM devices. A stress circuit ( 602 ) applies proper electrical stresses to one or more data devices ( 600 ) and a reference device ( 601 ). Data are represented by the property differences between the data devices and the reference device. Sometimes the reference device can be another data device. A sense circuit ( 604 ) senses the differences in device properties between them in order to read the data. FIG. 6 ( b ) shows the schematic diagram for one practical example of a SEPROM device. A SEPROM memory block ( 610 ) comprises a two dimensional (M by N) array of transistors. At the n'th row of the memory block, the gates for data transistors (M n1 , . . . , M nm , . . . , M nM ), and the gate for a reference transistor (M nr ) are connected together to a word line (WL n ) as shown in FIG. 6 ( b ). At the m'th column of the memory block, the drains for transistors M 1m , . . . , M nm , . . . , M Nm are connected together to a bit line (BL m ). The drains for reference transistors M 1r , . . . , M nr , . . . , M Nr are connected together to the reference bit line (BL r ). The sources of all those transistors are connected to ground. Each word line (WL n ) is connected to the output of a word line decoder ( 612 ). Each bit line (BL m ) is connected to the input of a bit line sensor ( 614 ) and the output of a bit line stress circuit ( 616 ). The reference bit line (BL r ) is connected to a reference signal generator ( 618 ) that generates a reference signal (Sr) to bit line sensors ( 614 ). During a write operation (also called “programming” operation in current art), one of the word line decoder ( 612 ) pulls the voltage on the selected word line (WL n ) to a voltage optimized for maximum stress rate (Vgst). All the other word lines remain at low voltages. The bit line stress circuits ( 616 ) provide bit line stress voltages to the bit lines (BL m ) according to the data values to be written to each transistor (M n1 , . . . , M nm , . . . , M nM , M nr ) on the selected row; to store a digital data ‘1’, the corresponding bit line voltage should be high, and the corresponding selected transistor will experience hot carrier stress; to store a digital data ‘0’, the corresponding bit line voltage should be zero, and the corresponding selected transistor will not be stressed; the reference bit line voltage usually remains low. The digital data certainly can be stored in opposite ways. Hot carrier effect damages transistors when the transistors are (1) on the selected word line and (2) on a bit line that is pulled high. In this way, data can be written into the memory block selectively. The selected word line voltage Vgst, should be controlled to have maximum hot carrier damage rate. During a read operation, one of the word line decoder ( 612 ) pulls the voltage on the selected word line (WL n ) to a high voltage. All the other word lines remain at zero. The voltage on the selected word line (WL n ) during a read operation should be high enough and the voltage on the bit lines should be low enough that the selected transistors (M n1 , . . . , M nm , . . . , M nM , M nr ) will not experience hot carrier effects during this operation. All the bit line stress circuits ( 616 ) should be off during this read operation. Each selected transistor (M n1 , . . . , M nm , . . . , M nM , M nr ) drives a current (I n1 , . . . , I nm , . . . , I nM , I nr ) through its corresponding bit line to corresponding bit line sensors ( 614 ); for a transistor that has been stressed in previous write operation, its bit line current should be smaller than the reference current (I nr ); for a transistor that has not been stressed in previous write operation, its bit line current should be about the same as or larger than the reference current (I nr ). The bit line sensor circuits ( 614 ) sense the amplitudes of those bit line currents to determine corresponding data values. If p-channel transistors, instead of n-channel transistors, are used in the memory block ( 610 ), then current differences may behave in opposite ways. It is a common practice to execute a read operation after a write operation in order to make sure correct data pattern has been written properly. Multiple write/read operations maybe necessary to assure correct data are written. During an erase operation, one of the word line decoder ( 612 ) pulls the voltage on the selected word line (WL n ) to a voltage optimized for maximum stress rate (Vgst). All the other word lines remain at zero. The bit line stress circuits ( 616 ) should drive zero to all bit lines except to the reference bit line. The reference bit line voltage should be high so that the selected reference transistor (M nr ) is under hot carrier stress. The reference transistor should be stressed as hard as all the other stressed transistors on the same word line so that new data can be written into the data transistors by another write operation. It is usually necessary to do a read operation following an erase operation in order to make sure enough stress has been done to the reference transistor. Multiple erase/read operations maybe necessary to assure the erase operation is properly done. While specific embodiments of the invention have been illustrated and described herein, it is realized that other modifications and changes will occur to those skilled in the art. It should be understood that the above particular examples are for demonstration only and are not intended as limitation on the present invention. For example, the bit line sensor circuits in FIG. 6 ( b ) senses the difference in transistor currents between two transistors experienced different levels of hot carrier damages. For a designer skilled in the art, there are infinite ways in designing the sensor circuits. The sensor can sense current, threshold voltage, transconductance, . . . etc. Each bit line sensor circuit can have a multiplexer so that only a sub-set of the bit line currents are sensed. We also can have multiple levels of bit line sensor/amplifier circuits for a large SEPROM device. To achieve optimum reliability, we can have one reference transistor for every one data transistor. The size of the reference transistor can be different from the data transistors. There are also infinite ways in designing the stress circuits. There are infinite ways in the configuration of the SEPROM memory blocks. We also can have multiple levels of memory blocks for large SEPROM devices. Hot carrier effects are used in the above example, while one can use Vg stress or other types of electrical stresses to alter the properties of transistors to achieve the same purpose. In the above example we use MOS transistors as the stressed devices. We also can use other types of devices. FIG. 6 ( c ) shows an example when bipolar transistors are used in the memory block, and FIG. 6 ( d ) shows an example when diodes are used. The SEPROM devices of the present invention have the following advantages: The major advantage is that SEPROM can be manufactured by any IC technologies. They are ideal for embedded applications. Each data point is memorized by one transistor; it is therefore possible to store large number of data at very low cost. The data stored in SEPROM devices are not detectable by any physical analysis, and the devices appear identical to any other transistors; it is therefore ideal for security applications. One potential disadvantage of SEPROM is that writing data to SEPROM can take longer time than writing to floating gate devices. This problem can be solved by many methods. For example, we can set the stress condition at maximum stress rate determined by existing data. Increasing stress voltages usually increase the stress rate exponentially. We also can reduce the channel length of the transistors to increase stress rate. Removing LDD will increase hot carrier effects significantly. Another disadvantage is that SEPROM devices can not be re-programmed for many times because the stress damage is usually accumulative. The stress damage can partially recover after initial programming. That is not a problem when the supporting sense circuit has enough margins. We also can refresh the data by writing the same data back into the SEPROM periodically. Above all, SEPROM devices provide the possibility to support a wide variety of novel applications. While specific embodiments of the invention have been illustrated and described herein, it is realized that other modifications and changes will occur to those skilled in the art. It is therefore to be understood that the appended claims are intended to cover all modifications and changes as fall within the true spirit and scope of the invention.

The present invention provides novel electrically programmable read only memory (EPROM) devices for embedded applications. EPROM devices of the present invention utilize existing circuit elements without complicating existing manufacture technologies. The novel EPROM device can be manufactured by applying the manufacturing processes used for making dynamic random access memory (DRAM), standard logic technologies or any type of IC manufacture technologies. Unlike conventional EPROM devices, these novel devices do not require high voltage circuits to support their programming operation. The EPROM devices of the present invention are ideal for embedded applications. Typical applications including the redundancy circuits for the programmable firmware for logic products, and the security identification circuits for IC products.

big_patent

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a technique of easily and quickly determining the optimum value of feedback gain used for calculating correction amount in feedback control. 2. Description of the Prior Art Feedback control is frequently adopted for, for instance, moving an automatic guidance vehicle along a predetermined course. The control comprises a step of detecting a deviation or error ΔE from the course, a step of calculating correction amount according to the detected error ΔE, and a step of correcting the steering angle of the vehicle according to the calculated correction amount, these steps being executed repeatedly. Generally, in the feedback control, the correction amount is calculated in any of the following ways: P system: A value (P×ΔE) which is proportional to the error is used as the correction amount. PI system: The sum of a value proportional to the error and a value proportional to an integral of the error (P×ΔE+I×integral of ΔE) is used as the correction amount. PD system: The sum of a value proportional to the error and a value proportional to a differential of the error (P×ΔE+D×differential of ΔE) is used as the correction amount. PID system: The sum of a value proportional to the error, a value proportional to an integral of the error and a value proportional to a differential of the error (P×ΔE+I×integral of ΔE+D×differential of ΔE) is used as the correction amount. The factors P, I and D as used in the above formula are feedback gains. Specifically, the P gain is a proportional gain, the I gain is an integral gain, and the D gain is a differential gain. The values of the feedback gains such as the P, I and D gains have great influence on the feedback control characteristics. For example, if the P or proportional gain is too small in value, the correction of the running course of the automatic guidance vehicle is delayed. If the gain is too large, on the other hand, the running course meanders greatly. Accordingly, on-site processes have heretofore been contemplated, which permit the optimum value of feedback gain to be found out easily and in a short period of time. A typical one of such processes is a limit sensitivity process which is disclosed in ASME trans., vol. 64, (1942. 11.), J. G. Ziegler, N. B. Nichols, pp. 759-768. In this limit sensitivity process, the magnitude of the P gain with which the error is undergoing self-sustaining vibration is obtained by carrying out actual feedback control on the subject of control, and the optimum value of each gain is determined from the value of the P gain at this time in accordance with experiment rules. Specifically, the I and D gains are set to zero, that is, the sole P gain is made variable in a trial feedback control, and the P gain is increased gradually. When the self-sustaining vibration of the error is obtained, the P, I and D gains are set to be, for instance: P gain=0.6×P c I gain=0.5×τ c D gain=0.125×τ c where P c is the value of the P gain at this time and τ c is the period of the self-sustaining vibration. In these formulas, the individual coefficients are obtained experimentally, and their adequacy empirically verified. In this way, the values of the P, I and D gains are determined. In the limit sensitivity process, however, problems are encountered in the practical way of detecting the self-sustaining vibration. Besides, depending on the subject of control, there may be cases when it is difficult to detect the reaching of the state of the self-sustaining vibration. As an example, in the feedback control for moving an automatic guidance vehicle (hereinafter referred to as AGV) along a course, it is not easy to accurately determine the instant of reaching of the self-sustaining vibration because of very slow changes in the course of the AGV. SUMMARY OF THE INVENTION An object of the invention is to provide a method of determining feedback gain which permits determining the proper value of feedback gain both easily and accurately, in a short period of time and irrespective of the kind of the subject of control. The method of determining feedback gain according to the invention, as schematically shown in FIG. 1, comprises a first step of provisionally determining a predetermined value of a feedback gain, a second step of executing feedback control by using the provisionally determined feedback gain, a third step of detecting an error between a designated value and an actual value of the subject of control during the execution of the second step, a fourth step of calculating an evaluation value indicative of the character of feedback control according to the error detected in the third step, a fifth step of executing the second to fourth steps repeatedly a plurality of times after provisionally determining a new feedback gain value different from the previous value, and a sixth step of calculating a feedback gain value which can provide for a suitable evaluation value according to the relation between the feedback gain value and the evaluation value obtained through the execution of the fifth step. This method permits a feedback gain providing for a suitable evaluation value to be calculated on the basis of the relation between feedback gain value and evaluation value, and it is thus possible to determine a feedback gain which can realize a suitable feedback control characteristic quickly and reliably. Particularly, in case of determining the proportional gain, in the fourth step, the ratio between the length of a curve obtained by plotting the error against time axis and the length of the time axis is calculated as the evaluation value, and in the sixth step, a feedback gain value providing for the minimum evaluation value is calculated. The proportional gain is a factor which influences the stability of control. The stability of control can be evaluated from the extent of variations of the error, and thus the length of the curve obtained by plotting the error against time axis is suited for evaluating the proportional gain. Thus, by using the length of the curve obtained by plotting the error against time axis as the evaluation value, it is possible to obtain quickly and accurately a value of the proportional gain that provides for the optimum stability. In case of determining the integral gain, in the fourth step, the evaluation value is calculated by integrating the error, and in the sixth step, a value of feedback gain that provides for an evaluation value closest to zero is calculated. The integral gain is a factor influencing the accuracy of control. The integral of the error reflects the accuracy of control, and is thus suited for evaluating the integral gain. Thus, by using the integral of the error, it is possible to obtain quickly and accurately a value of integral gain which provides for satisfactory accuracy. In case of determining the differential gain, in the fourth step, the evaluation value is calculated by integrating the absolute value of the error, and in the sixth step, a value of feedback gain providing for the evaluation value which is closest to zero is calculated. The differential gain is a factor influencing the response of control. The response of control can be evaluated to the fineness of error variations, and thus the integral of the absolute value of the error is suited for evaluating the differential gain. Thus, by using the integral of the absolute value of the error, it is possible to obtain quickly and accurately a value of differential gain providing for the optimum stability and response. The present invention will be more fully understood from the following detailed description and appended claims when taken with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view illustrating the method of determining feedback gain according to the invention; FIG. 2 is a schematic representation of an automatic guidance vehicle used in the method of determining feedback gain according to a first and a second embodiment of the invention; FIG. 3 is a block diagram showing controllers of the automatic guidance vehicle used in the method of determining feedback gain according to the first and the second embodiments; FIG. 4 is a view showing the amount of control and evaluation functions in the method of determining feedback gain according to the first and the second embodiments; FIG. 5 is a graph showing a proportional gain evaluation function in the method of determining feedback gain according to the first and the second embodiments; FIG. 6 is a graph showing an integral gain evaluation function in the method of determining feedback gain according to the first and the second embodiments; FIG. 7 is a graph showing a differential gain evaluation function in the method of determining feedback gain according to the first and the second embodiments; FIG. 8 is a plan view showing an automatic guidance vehicle running course in the method of determining feedback gain according to the first and the second embodiments; FIG. 9 is a flow chart showing a gain determination routine in the method of determining feedback gain according to the first embodiment; FIG. 10 is a flow chart showing part of the gain determination routine in the method of determining feedback gain according to the first embodiment; FIGS. 11(A) and 11(B) are graphs showing examples of gain determination process in the method of determining feedback gain according to the first embodiment; and FIG. 12 is a flow chart showing a gain determination routine in the method of determining feedback gain according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment Now, a first embodiment of the invention will be described with reference to FIGS. 2 to 11. In this embodiment, the method of feedback gain determination is applied to the running control of an AGV. First, the construction of the AGV in this embodiment will be described with reference to FIG. 2. FIG. 2 is a view showing the construction of an AGV 2 in this embodiment. As shown in FIG. 2, the AGV 2 runs along a running surface 8 with front wheels 4 as steering wheels and rear wheels 6 as drive wheels. A steering module 24 is provided for the steering wheels 4. The drive wheels 6 have brakes 32, and a drive module 28 and a brake module 30 are provided for the drive wheels 6. The steering module 24 is controlled by a steering angle controller 22, and the drive module 28 and brake module 30 are controlled by a vehicle speed controller 26. The steering angle controller 22 and the vehicle speed controller 26 are controlled by a central processor 10. The central processor 10 is a computer system including a central processing unit (CPU) 12, and a memory section having a ROM 14 and a RAM 16. The CPU 12, RAM 14 and ROM 16 are interconnected by data buses 18 for mutual data transfer. The underside of a central portion of the front end of the AGV 2 is provided with a lateral deviation detector 20. The lateral deviation detector 20 includes a sensor having a pick-up coil, and it detects by electromagnetic induction an induction wire which is laid on a running surface 8 along the running course of the AGV 2. The distance between the induction wire and the lateral deviation detector 20, i.e., the lateral deviation of the AGV 2, is detected from the magnitude of a detection signal output from the detector 20. The direction or sense of deviation, i.e., whether the AGV 2 is deviated to the left or right, is detected from the sign (either positive or negative) of the detection signal. The detection signal from the lateral deviation detector 20 is inputted to the central processor 10. The drive module 28 includes a vehicle speed detector 34, and a vehicle speed signal therefrom is inputted to the central processor 10. The central processor 10 executes a predetermined calculation process according to the inputted signals noted above. According to the result of the calculation process, the central processor 10 outputs a control signal to the steering angle controller 22 and the vehicle speed controller 26. The flow of a signal in the running control system for the AGV 2 will now be described in detail with reference to FIG. 3. FIG. 3 is a block diagram showing the running control system for the AGV 2. Referring to FIG. 3, designated at 34 is the vehicle speed detector which is provided in the AGV 2. A vehicle speed calculator 42 calculates the actual vehicle speed VA according to a signal from the vehicle speed detector 34. Designated at 36 is a vehicle speed designator, and at 38 an error calculator for calculating the error ΔV between a designated vehicle speed VT and the actual vehicle speed VA. Designated at 44 is a feedback gain storage in which feedback gains P V , I V and D V are stored. Designated at 40 is a correction amount calculator for calculating the vehicle speed correction amount from the error ΔV and feedback gains P V , I V and D V . The correction amount thus calculated is fed to the vehicle speed controller 26, which in turn controls the drive module 28 and the brake module 30. Thus, the actual vehicle speed VA is feedback controlled to be equal to the designated vehicle speed VT. Designated at 46 is a feedback gain controller for controlling the feedback gain to a proper value in the manner as will be described later. Designated at 48 is an error calculator for calculating the deviation or error a ΔE according to a signal from the lateral deviation detector 20. Designated at 54 is a feedback gain storage in which feedback gains P E , I E and D E are stored. Designated at 50 is a correction amount calculator for calculating the steering angle correction amount from the error ΔE and the feedback gains P E , I E and D E . The correction amount thus calculated is fed to the steering angle controller 22, which thus controls the steering module 24. Thus, the steering module 24 is feedback controlled such as to reduce the lateral deviation ΔE to zero. Designated at 52 is a feedback gain controller for controlling the feedback gain to a proper value in the manner as will be described later. In the running control system having the above constitution for controlling the running of the AGV 2, feedback control (or PID control) is carried out, which involves processes concerning the P (proportional), I (Integral) and D (differential) gains. In this PID control, the methods of determining the optimum values of the P, I and D gains will now be described with reference to FIGS. 4 to 7. As noted before, during the running of the AGV 2, a detection signal is outputted, which corresponds to the extent and direction of the deviation of the lateral deviation detector 20 from the induction wire which is laid along the running course. FIG. 4 shows an example of the detection signal. In FIG. 4, the ordinate is taken for the voltage value V of the detection signal from the lateral deviation detector 20, and the abscissa is taken for the running time of the AGV 2. The sign of the voltage value V indicates the direction (i.e., to the left or right) in which the lateral deviation detector 20 is deviated with respect to the induction wire. The voltage value V thus corresponds to the error. When the AGV 2 is running accurately along the induction wire, the voltage value of the detection signal is zero. In the running control of the AGV 2, it is thus necessary the curve ε(t) which represents the voltage value V plotted along the running time to be in as accord as the abscissa axis as possible. In addition, it is necessary to determine the optimum values of the P, I and D gains such that the result of control obtained satisfies all of the stability, accuracy and response. The P gain governs the stability of control, the I gain is a factor which influences the magnitude of off-set, i.e., the accuracy of control, and the D gain governs the response of control. Thus, in this embodiment, evaluation values are introduced about the individual P, I and D gains having the above characters for accurately evaluating the influence of the value of each gain on the voltage curve ε(t). Functions LR, Svv and Asv shown by formulas (1) to (3) in FIG. 4 give the evaluation values. In other words, the functions LR, Svv and Asv are evaluation functions for the P, I and D gains, respectively. The meaning of these functions will now be described with reference to FIG. 4. The function LR, as shown by the formula (1) in FIG. 4, represents the ratio between the length of the voltage curve ε(t) drawn in a measurement time (from instant C S till instant C E ) and the measurement time (C E -C S ). Thus, LR=1 is obtained in the ideal state of control. The stability of the running control can be evaluated from the extent of lateral deviations of the AGV 2. Thus, the evaluation function LR is suited for evaluating the relation between the stability of control and the P gain. The optimum value of the P gain can be obtained by controlling the P gain such that the function LR approaches the ideal value of unity. The function Svv, as shown by the formula (2) in FIG. 4, represents the product per 30 seconds of the summation of the measured voltage Vi in the measured time (C S -C E ) and constant C. The magnitude and sign of the integral of the measured voltage Vi directly reflect the magnitude and sign of the off-set of the error, and it is thus suited for evaluating the I gain. The ideal value of the function Svv is zero, and the optimum value of the I gain is obtained by controlling the I gain such that Svv approaches zero. The function Asv, as shown by the formula (3) in FIG. 4, represents the product per 30 seconds of the summation of the absolute value of the measured voltage Vi in the measured time (C E -C S ) and constant C. Its magnitude corresponds to the area enclosed by the voltage curve ε(t) and the abscissa shown in FIG. 4. The response of the running control can be evaluated from the fineness of the lateral deviations of the AVG, i.e., the fineness of the waveform of the curve ε(t) in FIG. 4. Thus, the function Asv is suited for evaluating the D gain which concerns the response of the running control. The response of control is the better the closer the value of Asv is to zero, and the optimum value of the D gain can be obtained by controlling the D gain such that Asv approaches zero. As shown, the evaluation functions are suited for evaluating the optimum values of the P, I and D gains. Besides, the evaluation functions have an advantage that by using them, the optimum value, of each gain can be obtained accurately irrespective of the settings of the other two gains. It is thus possible to very readily determine the optimum values of the P, I and D gains without using any of very complicated multiple variable analytic processes such as a linear plan process which have been required for obtaining optimum values of a plurality of mutually related functions. Now, how the evaluation functions change with gain changes will be described with reference to FIGS. 5 to 7. FIG. 5 shows the function LR plotted against the P gain, FIG. 6 shows the function Svv plotted against the I gain, and FIG. 7 shows the function Asv plotted against the D gain. The function LR, as shown in FIG. 5, draws a downward convex curve with changes in the P gain and is closest to the ideal value of unity at its minimum point. Thus, the value P opt of the P gain corresponding to the minimum point of the curve in FIG. 5 is the optimum value of the P gain. The function Svv, as shown in FIG. 6, is reduced uniformly as the I gain is increased and is zero at a certain point. Thus, the value I opt of the I gain corresponding to Svv=0 in the curve shown in FIG. 6 is the maximum value of the I gain. The function Asv, as shown in FIG. 7, draws a downward convex curve with changes in the D gain and is closest to the ideal value of zero at its minimum point. Thus, the value D opt of the D gain corresponding to the minimum point of the curve shown in FIG. 7 is the optimum value of the D gain. There are two different conceivable methods of obtaining the ideal values of gains from evaluation function data. In one of these methods, as shown in FIGS. 5 to 7, a fixed range with respect to the ideal value of each evaluation function is set as an optimum value range, and the value of gain when the value of the evaluation function enters this optimum value range is selected as the optimum value. In the other method, the optimum values P opt , I opt and D opt are calculated by function interpolation. More specifically, a plurality of evaluation function values are obtained such that they sandwich the optimum values P opt , I opt and D opt , and using these values, the curves shown in FIGS. 5 to 7 are plotted, thereby calculating the optimum values P opt , I opt and D opt . This function interpolation process has an advantage over the above method based on the optimum range that it is possible to obtain more optimum values. A specific example of obtaining the optimum values of the P, I and D gains in the AGV running control by using the above evaluation functions will now be described with reference to FIG. 8. FIG. 8 is a plan view showing the running course of the AGV in this embodiment. As shown in FIG. 8, the running course 70 of the AGV 2 in this embodiment is an oval closed loop consisting of four sections of different running conditions. In a section 72 of the course 70 from a point at a point b, the AGV 2 runs along a curve at low speeds. In a section 74 from the point b to a point c, it runs along a straight line at high speeds. In a section 76 from the point c to a point d, it runs along a curve at high speeds. In a section 78 from the point d to the point a, it runs along a straight line at low speeds. In the running control for driving the AGV 2 along such running course 70, the procedure for determining the optimum values of the P, I and D gains will be described with reference to FIGS. 9 and 10. FIGS. 9 and 10 are flow charts illustrating the procedure of determining the P, I and D gains in this embodiment. The routine shown in these flow charts is executed in the central processor 10. In this embodiment, data take-in and gain determination are done for each section of the running course shown in FIG. 8. For example, the AGV 2 is first driven repeatedly only in the section 72 for the data take-in, and first the P, I and D gains are determined for the section 72. Then, the AGV 2 is driven repeatedly only in the section 74 for the data take-in. Likewise, the AGV 2 is driven in the other sections. When the routine is started in Step S2, course conditions are set for either section (among the sections 72, 74, 76 and 78 in FIG. 8), for which the optimum values of the P, I and D gains are to be obtained (Step S4). Then, the values of the P, I and D gains are initialized (Step S6). That is, the individual gains are set to initial values which are preliminarily stored in the ROM 16 of the central processor 10 shown in FIG. 2. As each initial value, a sufficiently small value is set. Subsequently, a process of obtaining the optimum value of the P gain is first executed (Step S8). The contents of the process or routine in Step S8 will now be described with reference to FIG. 10. The routine is started in Step S20, and the AGV 2 is driven to run along the course 70 under feedback control using the initial values of the P, I and D gains that have been set in Step S6 in FIG. 9 (Step S22). Then, output voltage data from the lateral deviation detector 20 is taken into the central processor 10 (Step S24). The output voltage data is, for instance, ε(t) in FIG. 4, and by using this data, the value of the evaluation function LR for the P gain is calculated with the formula (1) in FIG. 4 (Step S26). Then, a check is made as to whether end conditions have been met by the value of LR (Step S28). If the end conditions have been met, that is, if the value of LR is in the optimum value range shown in FIG. 5, the value of the P gain at this time is determined as the optimum value (Step S30). As a result, the routine goes back to the routine shown in FIG. 9 (Step S32). If the end conditions have not been met by the value of LR, the value of the P gain is increased by a predetermined amount (Step S34), and then Step S22 seq. are repeatedly executed. When the routine shown in FIG. 9 is restored, Steps S10 and S12, i.e., a process of obtaining the optimum value of the I gain and a process of obtaining the optimum value of the D gain, are executed successively. These processes are similar to the process of obtaining the optimum value of the P gain shown in FIG. 10. Specifically, as for the I gain in Step S26 in FIG. 10, the value of the evaluation function Svv for the I gain is calculated with the formula (2) in FIG. 4. As for the D gain, in Step S26 in FIG. 10, the value of the evaluation function Asv for the D gain is calculated with the formula (3) in FIG. 4. If the values of Svv and Asv thus calculated are in the respective optimum value ranges shown in FIGS. 6 and 7, the values of the I and D gains at this time are determined as the optimum values. The optimum value data of the three different gains are stored together with the course condition data set in Step S4 as a set of data in the RAM 14 of the central processor 10 in FIG. 2. Then, a check is made as to whether the processes have been ended for all the sections of the running course 70 (Step S14 in FIG. 9). If "YES", the data for all the course sections are registered (Step S16), and the routine is ended (Step S18). If the result of the check in Step S14 is "NO", the routine goes back to Step S4 to execute similar operations for the next course section. In this way, the optimum values of the P, I and D gains are determined. In the routine of the flow charts of FIGS. 9 and 10, the value of each gain at the instant when the optimum value range shown in each of FIGS. 5 to 7 is entered is determined as the optimum value. However, as noted before, it is possible to obtain the individual gain optimum values (P opt , I opt and D opt in FIGS. 5 to 7) by the function interpolation. FIGS. 11(A) and 11(B) show specific examples of the P, I and D gains obtained in the above procedure. FIG. 11(A) shows the process contents until the P gain is determined in the procedure shown in FIG. 10, and FIG. 11(B) shows the process contents until determination of each of the P, I and D gains by function interpolation. In the example of FIG. 11(A), the P gain is increased from initial value P1 and up to P5, at which the evaluation value enters the optimum value range. More specifically, the value of the P gain is increased progressively from its value in a first calculation section for data take-in and calculation, and its value when the evaluation value LR is calculated in a fifth calculation section is in the optimum value range shown in FIG. 5. The P gain value at this time is thus determined as the optimum value. FIG. 11(B) shows the process of determining each of the P, I and D gains by function interpolation. First, the I and D gains are set to forecast optimum values I0 and D0, and in this state, the P gain is increased from initial value P1 in steps of a predetermined amount for taking output voltage data with actual running of the AGV and calculating the value of the evaluation function. When the minimum value is passed by the value of LR, the data take-in is stopped, and the optimum value Popt of the P gain is calculated by function interpolation with the values of LR that have been obtained. In the case of FIG. 11(A), the passage of the minimum value by the value of LR can be known at the instant when P gain value P6 is substituted, and the function interpolation is thus executed using the values of LR corresponding to the gain values P1 to P6, thus determining P opt , Then, using the calculated value P opt and the value DO the I gain is likewise increased from the initial value I1 in steps of a predetermined amount for calculating I opt . Further, using the values P opt and I opt , the value D opt is calculated likewise. In either of the examples of FIGS. 11(A) and 11(B), the value of each gain is increased in steps of an equal amount. However, it is possible to change the amount of increase not only for each gain but also for each step. Second Embodiment A second embodiment of the invention will now be described with reference to FIGS. 2, 8, 10 and 12. This embodiment, unlike the first embodiment, features that the P, I and D gains are determined by causing the AGV to run continuously along the running course. That is, the optimum P, I and D gains are determined for each of the sections 72, 74, 76 and 78 of the running course 70 shown in FIG. 8 while the AGV makes an excursion of the course. The construction of the AGV, the constitution of the running control system and the running course are the same as in the first embodiment. The procedure in this embodiment will now be described with reference to FIG. 12. FIG. 12 is a flow chart illustrating the gain determination procedure in the feedback gain determination method of the second embodiment. The process illustrated in the flow chart is executed in the central processor 10 shown in FIG. 2. When the routine is started in Step S52 in FIG. 12, the values of the P, I and D are initialized (Step S54). That is, the values of the individual gains are set to initial values which are preliminarily stored in the ROM16 of the central processor 10 in FIG. 2. Then, the AGV 2 is caused to run along the course 70 (Step S56). At each of the boundary points a to d between adjacent course sections, a marker is provided for transmitting a trigger signal, and a check is made as to whether a trigger signal from a marker has been inputted (Step S58). If the result of the check is "NO", the AGV is continually caused to run. Upon inputting of a trigger signal, the routine goes to Step S60, a process of obtaining the optimum value of the P gain. The process has the same contents as those in the first embodiment, and it is executed in the same way as the procedure shown in FIG. 10. Then, a process of obtaining the optimum value of the I gain (Step S62) and a process of obtaining the optimum value of the D gain (Step S64) are executed in succession. Optimum value data which are thus obtained for the three different gains are registered together with data indicative of the course sections as a set of data in the RAM 14 of the central processor 10 shown in FIG. 2 (Step S66). The data indicative of the source sections are read in accordance with the previously inputted trigger signals. Then, a check is made as to whether the optimum values of all the P, I and D gains have been registered for all the sections of the running course 70 (Step S68). If the result of the check is "YES", the routine is ended (Step S70). Now, data which are necessary for the automatic running of the AGV 2 along the running course 70 are at hand, and it is possible for the AGV 2 to perform predetermined operations. If the result of the check in Step S68 is "NO", the routine returns to Step S56 for executing similar operations for the next course section. As for the trigger signal inputting, instead of using the markers provided at the boundary points a to d, it is possible that the operator transmits a trigger signal by manual operation by watching the running AGV 2, or it is possible to adopt a system in which a trigger signal is outputted in the AGV 2 in accordance with the accumulated running distance. There may be a case when the next trigger signal is inputted (for the next course section) before the routine concerning the three different gains have not yet been ended due to such causes as short time necessary for the AGV 2 to cover the present course section and stringent end conditions shown in Step S28 in FIG. 10. In such case, the end conditions shown in Step S28 in FIG. 10 may be made less stringent to obtain the optimum values of the three gains. If the next trigger signal has not yet been inputted in this stage, the end conditions in Step S28 in FIG. 10 may be made more stringent, and the routine may go back to Step S60 as shown by dashed line in FIG. 12 to obtain more suitable optimum value for each gain. As a further alternative, a gain which could have not been calculated until the reaching of the next course section by the AGV, may be calculated concurrently with the data take-in for the next course section. In the flow chart shown in FIG. 12, the initial value of each gain set in Step S54 is used commonly for all the sections of the course as the initial value for the operation in Step S60 seq. By providing, between Steps S58 and S60, a step for inputting the initial value of each gain suited for each course section afresh in correspondence to the inputted trigger signal, it is possible to reduce the time necessary for the processing. Each of the above embodiments has concerned with an example in which the P (proportional control), I (integral control) and D (differential control) gains are obtained as feedback gains. However, the invention is also applicable to cases of obtaining the optimum values of feedback gains other than the P, I and D gains. Further, while in the first embodiment, the optimum values are obtained in the order of that for the P gain, that for the I gain and that for the D gain, it is possible to obtain the optimum values in any order. Further, the evaluation functions for the gains in the above embodiments are by no means limitative, and it is possible to use other functions so long as they are suited for the gain evaluation. Furthermore, the construction of the AGV, other steps of the feedback gain determination method etc. in the above embodiments are by no means limitative. While the invention has been described with reference to preferred embodiments thereof, it is to be understood that modifications or variations may be easily made without departing from the scope of the present invention which is defined by the appended claims.

A feedback gain determination method permits optimum values of such feedback gains as P, I and D gains to be determined easily, quickly, reliably, and irrespective of the kind of the subject of control. The method comprises a first step of provisionally determining a predetermined value of a feedback gain, a second step of executing feedback control by using the provisionally determined feedback gain, a third step of determining an error between a designated value and an actual value of the subject of control during the execution of the second step, a fourth step of calculating an evaluation value indicative of the character of feedback control according to the error detected in the third step, a fifth step of executing the second to fourth steps repeatedly a plurality of times after provisionally determining a new feedback value different from the previous value, and a sixth step of calculating a feedback gain value which provides for a suitable evaluation value according to the relation between the feedback gain value and the evaluation value obtained through the execution of the fifth step. The method permits easy and quick determination of the proper value of the gain.

big_patent

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to zoom lenses and, more particularly, to zoom lenses of increased relative aperture with good optical performance over the entire zooming range, while still permitting the physical size to me minimized with the total length shortened to be suited to photographic cameras, video cameras, etc. 2. Description of the Related Art To photographic cameras and video cameras there has been a demand for a zoom lens having a good compromise between the requirement of increasing the relative aperture with a high range and the requirement of reducing the bulk and size in such a manner that high grade optical performance is preserved. Of these, for the video camera, because of its image pickup element being relatively low in sensitivity, the zoom lens has to get as high a relative aperture as possible. At present, the 2/3 in. image pickup tube is widely used in the video camera from the two points of view of compactness and image quality. Also, from the standpoint of good manageability and high facility for further minimization of the size, 8 m/m video cameras are coming to be used in gradually increasing numbers. The image pickup tube to be used in this camera is required to be furthermore reduced in size while preserving high grade imagery. Recently the 1/2 in. image pickup tube or plate has found its use in 8 m/m video cameras. If the zoom lens is of the so-called 4-unit type in principle, it is in general case that an increase of the relative aperture to as high as 1.4-1.6 or thereabout in F-number can be achieved when proper rules of lens design are set forth particularly for the fourth lens unit that is arranged on the image side of the zoom section to be stationary during zooming, and the image forming section or the fifth lens unit to well correct the residual aberrations of the zoom section. Also, in order to shorten the total length of the entire lens system, the effective method is to reduce the bulk and size of the front or first lens unit. To allow for this to be achieved, the F-number may be increased. But, to avoid the F-number from being so much increased, it becomes important to set forth proper rules of design for the image forming section. In addition thereto, if the reduction of the physical size of the entire lens system and the increase of the relative aperture are attempted by relying merely on strengthening of the refractive power of each lens unit, then the spherical aberration in the paraxial region, the coma from the zonal to the marginal region, and higher order aberrations such as sagittal halo are increased largely. So, it becomes difficult to get high optical performance. Suppose, for example, the front or first lens unit is selected for shortening the total length by the method of increasing the refractive power, then the overall magnifying power of the zoom section up to the image forming section has to be increased. As a result, the first lens unit produces many aberrations, and the tolerances for the lens design parameters becomes severer. Thus, it becomes difficult to assure the prescribed optical performance. Also, in the case of using the 2/3 in. image pickup element, according to the prior art, the total length L of the entire lens system in terms of the diagonal φ A of the effective picture frame falls in a range of 10φ A to 12φ A , as disclosed in Japanese Laid-Open Patent Application No. Sho 60-260912. This implies that the total length of the entire lens system is caused to become comparatively long. Like this, it has been very difficult to achieve a reduction of the total length L to shorter than 10φ A in such a manner that good optical performance is preserved throughout the zooming range. As other concomitant techniques mention may be made of U.S. Pat. Nos. 4,518,228, 4,525,036, 4,618,219, 4,621,905, 4,653,874, and 4,659,187. SUMMARY OF THE INVENTION An object of the present invention is to provide a zoom lens having a small F-number, a high zoom ratio and the standard image angle at the wide angle end with the size of the entire lens system being reduced while still permitting high grade optical performance to be preserved throughout the entire zooming range. The zoom lens of the invention comprises, from front to rear, a first lens unit of positive power for focusing, a second lens unit of negative power having the magnification varying function, a third lens unit of negative power for compensating for the shift of an image plane resulting from the variation of the magnification, a fourth lens unit having a positive lens for making the diverging light beam from the third lens unit an almost parallel light beam, and a fifth lens unit having an image forming function and having lenses of positive, negative, positive, negative, positive and positive powers in this order, wherein letting the focal length of the j-th lens in the i-th lens unit be denoted by f i ,j, the radius of curvatyre of the j-th lens surface in the i-th lens unit by R i ,j, the Abbe number of the glass of the j-th lens in the i-th lens unit by ν i ,j, and the focal length of the i-th lens unit by Fi, the following conditions are satisfied: 0.7<|R.sub.4,2 /F.sub.4 |<0.85 (1) 1.05<|f.sub.5,2 /F.sub.5 |<1.5 (2) 0.6<|f.sub.5,4 /f.sub.5,5 |<1.5 (3) 50<(ν.sub.5,1 +ν.sub.5,6)/2<59 (4) BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal section view of a typical one of examples of specific zoom lenses of the invention. FIGS. 2(A) and 2(B) to FIGS. 5(A) and 5(B) are graphic representations of the aberrations of numerical examples 1 to 4 of the invention respectively, with FIGS. 2(A), 3(A), 4(A) and 5(A) in the wide angle end, and FIGS. 2(B), 3(B), 4(B) and 5(B) ij tge telephoto end. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the form of a zoom lens of the invention in correspondence to numerical examples thereof. In the figure, I is a first lens unit of positive refractive power axially movable for focusing. II is a second lens unit of negative refractive power axially movable for varying the image magnification. III is a third lens unit of negative refractive power for compensating for the shift of an image plane as it occurs when the image magnification varies. IV is a fourth lens unit of positive refractive power for making the diverging light beam incident thereon from the third lens unit III almost afocal in emerging therefrom. V is a fixed fifth lens unit having the image forming function and comprising six lens elements of positive, negative, positive, negative, positive and positive powers in this order. SP is a fixed, aperture size-variable diaphragm. In the embodiments of the invention, in such a zoom type, by satisfying the above-mentioned inequalities of conditions (1)-(4) for the construction and arrangement of the elements of the fourth and fifth lens units, despite a great increase in each of the relative aperture and the range of variation of the magnification, good correction of aberrations is achieved for high grade optical performance throughout the entire zooming range. The technical signifcances of the above-defined conditions each are explained below. The inequalities of condition (1) represent the range of refracting power for the rear surface of the first lens in the fourth lens unit. The use of a lens form of strong rearward curvature in the first lens of the fourth lens unit leads to production of various aberrations, particularly spherical aberration and coma, when the light beam diverging in passing through the first to the third lens units travels across that lens. In order that the light beam leaves as an almost afocal one for the fifth lens unit without causing such aberrations to be increased as far as possible, the condition (1) must be satisfied. Also, the requirement of making up the almost afocal beam from the diverging light beam of the third lens unit, when fulfilled, unequivocally determines the refractive power for the fourth lens. For this reason, when the refracting power of the rear lens surface becomes too weak as exceeding beyond the upper limit of the inequalities of condition (1), the refracting power of the front lens surface must be so much increased. As a result, the tendency toward under-correction of spherical aberration is intensified. When the refracting power of the rear lens surface becomes too strong beyond the lower limit, on the other hand, the coma is increased largely. The inequalities of condition (2) give a range of refractive power ratio for the second lens in the fifth lens unit to the whole of the fifth lens unit to well correct particularly spherical aberration. When the upper limit is exceeded, it is over-corrected. When the lower limit is exceeded, under-correction comes to result. The inequalities of condition (3) give a range of refractive power ratio for the fourth and fifth lenses in the fifth lens unit to well correct astigmatism without causing other aberrations, mainly coma, to be produced as far as possible. When the upper limit is exceeded, the coma is increased largely. When the lower limit is exceeded, the astigmatism becomes difficult to well correct. The inequalities of condition (4) give a range of the Abbe numbers of the media of the first and sixth lenses in the fifth lens unit to correct longitudinal and lateral chromatic aberrations in good balance. When the upper limit is exceeded, over-correction of longitudinal chromatic aberration results. When the lower limit is exceeded, the lateral chromatic aberration is under-corrected objectionably. In order to achieve a reduction of the physical length of the entire lens system while minimizing the variation with zooming of the aberrations, it is preferred to satisfy the following condition: 0.75<|F.sub.2 /Fw|<0.85 (5) where Fw is the shortest focal length of the entire system. The factor in the inequalities of condition (5) represents the refractive power of the second lens unit. When the lower limit is exceeded, the refractive power of the second lens unit becomes too strong, causing the range of variation of aberrations with zooming to increase. When the refractive power of the second lens unit becomes weak beyond the upper limit, the physical length is increased objectionably, because it must be compensated for by increasing the total zooming movement of the second lens unit to obtain the equivalent zoom ratio. The objects of the invention are accomplished when all the conditions set forth above are satisfied. Yet, to achieve a further improvement of the aberration correction, it is preferred that the fourth and fifth lens units are constructed in such forms as described below. The fourth lens unit is a bi-convex lens with the rear surface of strong curvature toward the rear. The fifth lens unit comprises, from front to rear, a bi-convex first lens with the front surface having a stronger curvature than the rear surface, a negative meniscus-shaped second lens of forward convexity, a positive third lens with the front surface of strong curvature toward the front, a negative meniscus-shaped fourth lens of forward convexity, a bi-convex fifth lens with the rear surface of strong curvature, and a positive sixth lens with the front surface of strong curvature toward the front. The air separation between the third and fourth lenses is longest in this lens unit. It should be noted that the term "rear surface of strong curvature" means that it is compared with the curvature of the other or front surface. This applies to the term "front surface of strong curvature" as well. By designing the fourth and fifth lens units in such a way, the residual aberrations, for example, spherical aberration and inward coma from the zonal to the marginal region of the picture frame, of the zoom section are corrected entirely in good balance. Four examples of specific zoom lenses of the invention can be constructed in accordance with the numerical data given in the following tables for the radii of curvature, R, the axial thicknesses or air separations, D, and the refractive indices, N, and Abbe numbers, ν, of the glasses of the various lenses with the subscriptions numbered consecutively from front to rear. A block defined between flat surfaces R28 and R29 represents a face plate, or a filter. The values of the factors in the above-cited conditions for the numerical examples are given in Table 1. ______________________________________Numerical Example 1 (FIGS. 2(A) and 2(B))F = 1-5.56 FNo = 1:1.6-2.4 2ω = 47.6°-9.0°______________________________________R1 = 4.9342 D1 = 0.0945 N1 = 1.80518 ν1 = 25.4R2 = 2.3937 D2 = 0.4961 N2 = 1.51633 ν2 = 64.1R3 = -10.2228 D3 = 0.0118R4 = 2.1189 D4 = 0.3622 N3 = 1.60311 ν3 = 60.7R5 = 11.8103 D5 = VariableR6 = 5.1504 D6 = 0.0630 N4 = 1.69680 ν4 = 55.5R7 = 0.9067 D7 = 0.2717R8 = -1.1671 D8 = 0.0630 N5 = 1.69680 ν5 = 55.5R9 = 1.1671 D9 = 0.2441 N6 = 1.84666 ν6 = 23.9R10 = 11.5367 D10 = VariableR11 = -2.2007 D11 = 0.0630 N7 = 1.71300 ν7 = 53.8R12 = -50.7152 D12 = VariableR13 = 9.2253 D13 = 0.3465 N8 = 1.69680 ν8 = 55.5R14 = -1.7144 D14 = 0.0787R15 = Stop D15 = 0.1575R16 = 2.7254 D16 = 0.2913 N9 = 1.65844 ν9 = 50.9R17 = -11.0099 D17 = 0.1417R18 = -1.8215 D18 = 0.0866 N10 = 1.84666 ν10 = 23.9R19 = -7.3111 D19 = 0.0118R20 = 1.6340 D20 = 0.2520 N11 = 1.56384 ν11 = 60.7R21 = 6.1695 D21 = 0.8189R22 = 2.5700 D22 = 0.0630 N12 = 1.83400 ν12 = 37.2R23 = 1.2021 D23 = 0.1024R24 = 1.8982 D24 = 0.2362 N13 = 1.51633 ν13 = 64.1R25 = -2.9332 D25 = 0.0118R26 = 3.6846 D26 = 0.2283 N14 = 1.51742 ν14 = 52.4R27 = -15.6427 D27 = 0.3150R28 = ∞ D28 = 0.4331 N15 = 1.51633 ν15 = 64.1R29 = ∞______________________________________f 1 5.56______________________________________D5 0.0910 1.5119D10 1.5019 0.2231D12 0.2359 0.0938Total Length = 8.109 (= 9.19 · φ.sub.EA)______________________________________ ______________________________________Numerical Example 2 (FIGS. 3(A) and 3(B))F = 1-5.56 FNo = 1:1.6-2.4 2ω = 47.6°-9.0°______________________________________R1 = 4.9314 D1 = 0.0945 N1 = 1.80518 ν1 = 25.4R2 = 2.3926 D2 = 0.5042 N2 = 1.51633 ν2 = 64.1R3 = -10.2219 D3 = 0.0118R4 = 2.1255 D4 = 0.3624 N3 = 1.60311 ν3 = 60.7R5 = 11.9694 D5 = VariableR6 = 5.5784 D6 = 0.0630 N4 = 1.69680 ν4 = 55.5R7 = 0.9197 D7 = 0.2721R8 = -1.1850 D8 = 0.0630 N5 = 1.69680 ν5 = 55.5R9 = 1.1855 D9 = 0.2285 N6 = 1.84666 ν6 = 23.9R10 = 10.6989 D10 = VariableR11 = -2.1763 D11 = 0.0788 N7 = 1.71300 ν7 = 53.8R12 = -40.3230 D12 = VariableR13 = 9.2309 D13 = 0.3545 N8 = 1.69680 ν8 = 55.5R14 = -1.7155 D14 = 0.0788R15 = Stop D15 = 0.1800R16 = 3.0328 D16 = 0.2758 N9 = 1.65844 ν9 = 50.9R17 = -7.4073 D17 = 0.1534R18 = -1.7877 D18 = 0.0867 N10 = 1.84666 ν10 = 23.9R19 = -6.5984 D19 = 0.0118R20 = 1.5956 D20 = 0.2994 N11 = 1.56384 ν11 = 60.7R21 = 7.4734 D21 = 0.8036R22 = 4.0283 D22 = 0.0630 N12 = 1.83400 ν12 = 37.2R23 = 1.1962 D23 = 0.0561R24 = 1.6708 D24 = 0.3230 N13 = 1.51823 ν13 = 59.0R25 = -2.3852 D25 = 0.0118R26 = 2.9824 D26 = 0.1418 N14 = 1.51742 ν14 = 52.4R27 = ∞ D27 = 0.3151R28 = ∞ D28 = 0.3151 N15 = 1.51633 ν15 = 64.1R29 = ∞______________________________________f 1 5.56______________________________________D5 0.0907 1.5128D10 1.5412 0.2586D12 0.2329 0.0934Total Length = 8.0734 (= 9.15 · φ.sub.EA)______________________________________ ______________________________________Numerical Example 3 (FIGS. 4(A) and 4(B))F = 1-5.56 FNo = 1:1.6-2.4 2ω = 47.3°-9.18°______________________________________R1 = 4.9866 D1 = 0.0956 N1 = 1.80518 ν1 = 25.4R2 = 2.4194 D2 = 0.5099 N2 = 1.51633 ν2 = 64.1R3 = -10.3364 D3 = 0.0120R4 = 2.1493 D4 = 0.3665 N3 = 1.60311 ν3 = 60.7R5 = 12.1034 D5 = VariableR6 = 5.6408 D6 = 0.0637 N4 = 1.69680 ν4 = 55.5R7 = 0.9300 D7 = 0.2752R8 = -1.1983 D8 = 0.0637 N5 = 1.69680 ν5 = 55.5R9 = 1.1988 D9 = 0.2310 N6 = 1.84666 ν6 = 23.9R10 = 10.8187 D10 = VariableR11 = -2.2007 D11 = 0.797 N7 = 1.71300 ν7 = 53.8R12 = -40.7745 D12 = VariableR13 = 9.4928 D13 = 0.3585 N8 = 1.69680 ν8 = 55.5R14 = -1.7292 D14 = 0.0797R15 = Stop D15 = 0.1593R16 = 3.1390 D16 = 0.2788 N9 = 1.65844 ν9 = 50.9R17 = -7.0677 D17 = 0.1502R18 = -1.8030 D18 = 0.0876 N10 = 1.84666 ν10 = 23.9R19 = -6.3846 D19 = 0.0120R20 = 1.5990 D20 = 0.3027 N11 = 1.56384 ν11 = 60.7R21 = 7.3765 D21 = 0.8126R22 = 4.2344 D22 = 0.0637 N12 = 1.83400 ν12 = 37.2R23 = 1.2054 D23 = 0.0700R24 = 1.7071 D24 = 0.3266 N13 = 1.51823 ν13 = 59.0R25 = -2.3530 D25 = 0.0120R26 = 3.0106 D26 = 0.1434 N14 = 1.51742 ν14 = 52.4R27 = -95.6033 D27 = 0.3187R28 = ∞ D28 = 0.3187 N15 = 1.51633 ν15 = 64.1R29 = ∞______________________________________f 1 5.56______________________________________D5 0.0918 1.5297D10 1.5584 0.2615D12 0.2350 0.0939Total Length = 8.1461 (= 9.13 · φ.sub.EA)______________________________________ ______________________________________Numerical Example 4 (FIGS. 5(A) and 5(B))F = 1-5.56 FNo = 1:1.6-2.4 2ω = 47.6°-9.0°______________________________________R1 = 4.9254 D1 = 0.1102 N1 = 1.80518 ν1 = 25.4R2 = 2.3897 D2 = 0.4934 N2 = 1.51633 ν2 = 64.1R3 = -10.2094 D3 = 0.0118R4 = 2.1229 D4 = 0.3620 N3 = 1.60311 ν3 = 60.7R5 = 11.9548 D5 = VariableR6 = 5.5715 D6 = 0.0630 N4 = 1.69680 ν4 = 5.5R7 = 0.9186 D7 = 0.2718R8 = -1.1836 D8 = 0.0630 N5 = 1.69680 ν5 = 55.5R9 = 1.1841 D9 = 0.2282 N6 = 1.84666 ν6 = 23.9R10 = 10.6858 D10 = VariableR11 = -2.1737 D11 = 0.0787 N7 = 1.71300 ν7 = 53.8R12 = -40.2737 D12 = VariableR13 = 9.2196 D13 = 0.3541 N8 = 1.69680 ν8 = 55.5R14 = -1.7134 D14 = 0.0787R15 = Stop D15 = 0.1479R16 = 3.4482 D16 = 0.2675 N9 = 1.51633 ν9 = 64.1R17 = -5.6826 D17 = 0.1841R18 = -1.5079 D18 = 0.0866 N10 = 1.84666 ν10 = 23.9R19 = -2.8542 D19 = 0.0118R20 = 1.5567 D20 = 0.3620 N11 = 1.60311 ν11 = 60.7R21 = -43.2099 D21 = 0.6372R22 = -5.5552 D22 = 0.0630 N12 = 1.83400 ν12 = 37.2R23 = 1.3759 D23 = 0.1036R24 = 4.4717 D24 = 0.3305 N13 = 1.51633 ν13 = 64.1R25 = -1.3545 D25 = 0.0118R26 = 2.0246 D26 = 0.2203 N14 = 1.51742 ν14 = 52.4R27 = ∞ D27 = 0.3148R28 = ∞ D28 = 0.3148 N15 = 1.51633 ν15 = 64.1R29 = ∞______________________________________f 1 5.56______________________________________D5 0.0885 1.5088D10 1.5393 0.2583D12 0.2326 0.0933Total Length = 8.0698 (= 9.16 · φ.sub.EA)______________________________________ TABLE 1______________________________________ Numeri- Numeri- Numerical Numerical cal Ex- cal Ex-Conditions Example 1 Example 2 ample 3 ample 4______________________________________(1) |R.sub.4,2 /F.sub.4 | 0.8156 0.8153 0.8129 0.8153(2) |f.sub.5,2 /F.sub.5 | 1.1123 1.1068 1.1329 1.4736(3) |f.sub.5,4 /f.sub.5,5 | 1.2187 1.0575 1.0392 0.6413(4) (ν.sub.5,1 + ν.sub.5,6)/2 51.65 51.65 51.65 58.25(5) |F.sub.2 /Fw| 0.7874 0.7880 0.7968 0.7870 Total Length 9.19φ.sub.EA 9.15φ.sub.EA 9.13φ.sub.EA 9.16φ.sub.EA of Lens______________________________________ It will be appreciated from the foregoing that according to the present invention, it is made possible to realize a large relative aperture, high range zoom lens of reduced size, while still preserving high grade optical performance, suited to photographic camera or video camera. In particular, the present invention has achieved a great advance in reduction of the size of the zoom lens in terms of the total length to as short as L=9.13φ A to 9.19φ A .

A zoom lens comprising a positive first lens unit for focusing, a negative second lens unit as the variator, a negative third lens unit as the compensator, a positive fourth lens unit for making afocal the diverging light beam from the third unit in travelling thereacross, and an image forming or fifth lens unit having six lenses, satisfying the following conditions: 0.7<|R.sub.4,2 /F.sub.4 |<0.85 1.05<|f.sub.5,2 /F.sub.5 |<1.5 0.6<|f.sub.5,4 /f.sub.5,5 |<1.5 50<(ν.sub.5,1 +ν.sub.5,6)/2 59 where R 4 ,2 is the radius of curvature of the second surface counting from front of the fourth lens unit, F 4 and F 5 are the focal lengths of the fourth and fifth lens units respectively; f 5 ,2, f 5 ,4, and f 5 ,5 are the focal lengths of the second, fourth and fifth lenses in the fifth lens unit, and ν 5 ,1 and ν 5 ,6 are the Abbe numbers of the glasses of the first and sixth lenses in the fifth lens unit, respectively.

big_patent

[0001] This is a national stage of PCT/AT2011/000461 filed Nov. 15, 2011 and published in German, which has a priority of Austria, no. A 1897/2010 filed Nov. 17, 2010, hereby incorporated by reference. FIELD OF THE INVENTION [0002] The present invention relates to a method for detecting elementary particles such as for example protons, ions, electrons, neutrons, photons or the like in a detector, wherein a charge pulse is generated in the detector when a particle passes through the detector and every charge pulse is subsequently converted into an electric signal and the signal is indicated and/or recorded, in particular after amplification, wherein individual signals are amplified in a first, fast amplifier and/or a plurality of signals are each integrated in a second, slow amplifier. The present invention, moreover, relates to a device for detecting elementary particles such as for example protons, ions, electrons, neutrons, photons or the like, including a detector for generating a charge pulse in the detector when a particle passes therethrough, wherein at least one consecutively arranged amplification device for converting every charge pulse into an electric signal and amplifying the same, and optionally a display and/or recording device, are provided, wherein, a first, fast amplifier for amplifying individual signals and a second, slow amplifier for integrating signals are provided. PRIOR ART [0003] In order to detect elementary particles such as protons, ions, electrons, neutrons, photons or the like in a detector, a detection or acquisition is usually performed in that an integration of a plurality of signals is performed at high frequencies or signal rates, wherein, upon amplification during such integration, an electric signal is substantially displayed or recorded as a function of the number or plurality of detected particles. The detection of individual particles can usually only be performed at comparatively low frequencies or signal rates while taking into account the options of a resolution of individual pulses or signals, wherein, as opposed to the integration of signals, such embodiments of detectors or detection devices require completely different structures of amplification and evaluation devices arranged to follow the detector. According to the presently known and available methods and devices, it is necessary to know in advance possible frequencies or signal rates in order to perform, in exceptional cases, a detection of individual particles for adaptation to count or signal rates to be expected, or, in particular with high-energy particles, to acquire data substantially averaged, over an extended or large period of time by an integration of the signals. In known methods and devices, it is thus normally not possible by one and the same device to both detect individual particles and their sequences or pulses over time and use an integration of particles when exceeding a count rate or signal rate in order to maintain a result averaged over an extended period of time. [0004] A method and a device of the kind mentioned initially can be taken from WO 2007/010448 A2, for example, wherein for a X-ray detector a counting channel and an integrating channel being separate therefrom are provided for allowing a quantitative evaluation of information with a CT scanner, for example. [0005] Further methods and devices for detecting different radiation and/or elementary particles, sometimes using several, potentially different detectors are known from US 2007/0075251 A1, US 2008/099689 A1, U.S. Pat. No. 3,579,127 A, U.S. Pat. No. 3,805,078 A or WO 97/00456 A1, for example. SUMMARY OF THE INVENTION [0006] The invention, therefore, aims to provide a method and device for detecting elementary particles of the initially defined kind, by which the above-mentioned drawbacks of the prior art can be reduced or completely avoided, and, in particular, to provide a method and device which enable both a measurement or detection of individual particles and an integration of count rates, in particular upon exceeding of a given threshold value for signal rates, as a function of such signal rates or desired boundary conditions, without knowing in advance count or signal rates to be expected and allow a reliable detection or evaluation of small-size signals. [0007] To solve these objects, a method of the initially defined kind is essentially characterized in that discharging of a charge pulse or signal from the detector is performed on the low-voltage side. In that both an amplification of individual signals in a fast amplifier and, or alternatively, an integration of each of a plurality of signals in a second, slow amplifier are performed, it has become possible by a joint method, as opposed to the prior art, to provide both the detection or measurement of individual pulses or signals and the integration thereof, in particular where correspondingly high count rates occur, without knowing in advance count or signal rates to be possibly expected. The method according to the invention thus enables the detection of signals or pulses generated by elementary particles irrespectively of a, previous restriction as required in the prior art in respect to a possible detection of individual particles or an integration of the same. When detecting elementary particles, the detection and evaluation of small-size signals is usually required such that a good signal/noise ratio has to be sought. In order to avoid excessive noise, and enable a simpler distinction of such signals having small sizes relative to a base quantity, for instance a base voltage or a base current, it is thus proposed according to the invention that discharging of a charge pulse or signal from the detector is performed on the low voltage side. In that according to the invention discharging of a charge pulse or signal is provided on the low-voltage side of the detector, the distinction from a background, and/or detection, of small-size signals has become much simpler as compared to the prior art, where signals are tapped or detected on the high-voltage side required for operating the detector. The low-voltage-side discharge or wiring provided by the invention will, in particular, prevent a leakage current in a high-voltage cable possibly having a large length from being detected such that, in the main, the precise measuring of the measurement current of a detector will be enabled. [0008] According to a preferred embodiment, it is proposed in this context that, as a function of the rate of the electric signals, individual signals are amplified in the first, fast amplifier and signals are integrated in the second, slow amplifier at least upon exceeding of a threshold value of the rate of the signals. In this manner, the measuring or detecting of individual particles is feasible at low rates or frequencies, in particular as a function of the signal rate actually occurring during measuring, while enabling the integration of each of a plurality of signals from at least a threshold value or limit value. [0009] For a simple and proper subdivision into measurements of individual signals or pulses, or an integration of each of a plurality of detection signal amplifications differing therefrom, it is proposed according to a further preferred embodiment that the signals are separated as a function of the rate by a capacitor preceding at least a first amplifier for amplifying individual low-rate signals, or a high-pass element, and/or by an inductive element preceding at least a second amplifier for amplifying high-rate signals, or a low-pass element. By appropriately selecting the characteristic data or parameters of the elements arranged to precede the individual amplifiers, it has thus become possible, for instance also as a function of different measuring conditions or different elementary particles to be detected, or parameters threreof, to provide, if desired, an adjustment in view of a separate, or optionally also simultaneous, detection of individual signals or pulses as well as an integration of each of a plurality thereof for detecting an averaged value over an extended period of time. [0010] In particular as a function of the individual elements used for amplification and signal processing, it is proposed according to a further preferred embodiment that amplifications in the different amplifiers are performed at overlapping rates of signals. By detecting signals in the different amplifiers at overlapping rates of signals, a check and, if required, a calibration within the overlapping range with a simultaneous detection of individual signals or pulses as well as an integration of each of a plurality thereof have also become possible, while providing a plurality of different parameters or characteristic data of the detected elementary particles. [0011] While electrically charged particles generate appropriate electric signals in a detector, it is proposed according to a further preferred embodiment of the method according to the invention for detecting uncharged particles that the detector material is doped or coated with a converter material for the detection of uncharged particles. By providing such a converter material, electric pulses are generated by an uncharged particle when passing through the detector material because of said converter material, which electric pulses will subsequently serve to detect such an uncharged particle. [0012] In order to detect particles over very wide ranges of possible signal or count rates, or large bandwidths, it is proposed according to a further preferred embodiment that a material enabling fast charge transport at room temperature, e.g. diamond, is used as said detector material. Such detector materials enabling fast charge transports at room temperature, for instance, enable not only the detection of individual particles up to high count or signal rates at a high time resolution, but also the precise and reliable integration of each of a plurality of such pulses or signals. Besides the fastness and insensitiveness to light, the radiation strength of diamond is, for instance, also a selection criterion for such a detector material. [0013] To solve the above-cited objects, a device of the initially defined kind is, moreover, essentially characterized in that the tapping of the charge pulses or signals is provided on the low-voltage side of the detector, in particular with the arrangement of a support capacitor. As already pointed out above, it has thus become possible to provide both the detection of individual pulses or signals and the detection of a value averaged over an extended period of time by integrating each of a plurality of such signals using a joint device and, for instance, without knowing in advance count rates or signal rates to be expected in particular in order to improve the noise/signal ratio, it is proposed according to the invention that the tapping of the charge pulses or signals is provided on the low-voltage side of the detector, in particular with the arrangement of a support capacitor. As already pointed out above, the detection of an interfering leakage current in a high-voltage cable possibly having a large length can be prevented by tapping the charge pulses or signals on the low-voltage-side. Due to the support capacitor preferably provided by the invention, the discharge of the detector can be rapidly compensated for by the support capacitor, in particular at high beam rates, whereby it is, in particular, possible to keep the detector voltage at normal voltage and maintain the functionality of the detector even at high ionization rates. In this respect, it is essential that the wiring of a support capacitor will only be enabled if the charge pulses or signals are tapped on the low-voltage side as is preferably provided by the invention. [0014] In this respect, it is proposed according to a preferred embodiment that the second, slow amplifier is provided for integrating signals upon exceeding of a threshold value of the rate of said signals. [0015] For a reliable and simple separation during the detection of signals of elementary particles when performing a measurement of individual pulses or signals, and/or an integration of each of a plurality thereof, it is proposed according to a further preferred embodiment that, for separating the signals as a function of the rate, at least one amplification element for amplifying low-rate signals is preceded by a capacitor for blocking high-frequency signals, or a high-pass filter, and/or at least one amplifier for amplifying high-rate signals is preceded by an inductive element, or a low-pass filter, for blocking low-rate signals. As already pointed out above, it has become possible, by selecting or adjusting the parameters of the individual elements of the amplifier, or the elements preceding the same, to appropriately adjust the measuring ranges for measuring individual particles, or each integrating the same, optionally by taking into account measuring conditions and/or measuring parameters. [0016] For instance for calibrating the different measuring methods possible in the device according to the invention within a signal or count rate range in which both a measurement and detection of individual particles or pulses and an integration of the same is possible, it is, moreover, proposed that the capacity of the capacitor and/or the inductance of the inductive element or the properties of the low-pass filter are selected for separating signals at overlapping rates, as in correspondence with a further preferred embodiment of the device according to the invention. [0017] While, as already mentioned above, the detection of charged Particles is substantially directly enabled as the latter Pass through the detector by generating electric pulses or signals, it is proposed according to a further preferred embodiment for detecting uncharged particles that the detector material is provided with an implanted converter material or at least a coating comprising a converter material for the detection of uncharged particles. [0018] In particular when taking into account the possibly high count rates or signal rates encountered in the detection of elementary particles, it is proposed according to a further preferred embodiment that a material enabling fast charge transport at room temperature, e.g. diamond, is provided as said detector material. [0019] To solve the above-cited objects, the invention, moreover, proposes the use of a method according to the invention or a preferred embodiment thereof, or a device according to the invention or a preferred embodiment thereof, for detecting particles in particle accelerators, in reactor installations, in diagnostic devices such as X-ray devices, CT devices or the like. SHORT DESCRIPTION OF THE DRAWINGS [0020] In the following, the invention will be explained in more detail by way of exemplary embodiments schematically illustrated in the drawing, Therein: [0021] FIG. 1 is a schematic wiring diagram of a device according to the invention for carrying out the method of the invention for detecting elementary particles; [0022] FIG. 2 is a schematic illustration of a detector to be used in a device according to the invention for carrying out the method of the invention, substantially in consideration of the flow chart according to FIG. 1 , FIG. 2 a depicting a schematic top view of such a detector, including an energy supply and a signal discharge, and FIG. 2 b illustrating a section along line II of FIG. 2 a; [0023] FIG. 3 is a schematic wiring diagram of a first embodiment a first amplifier and a second amplifier disposed downstream of the detector; [0024] FIG. 4 in an illustration similar to that of FIG. 3 depicts a modified embodiment of a first amplifier disposed downstream of the detector, of a device according to the invention for carrying out the method of the invention; [0025] FIG. 5 is a schematic illustration of different measuring ranges when measuring individual particles and integrating a plurality of measurements; [0026] FIG. 6 schematically illustrates different measurements, FIG. 6 a illustrating the measurement or detection of individual signals or pulses, and FIG. 6 b depicting the integration of each of a plurality of signals or pulses; [0027] FIG. 7 is a schematic illustration of a detector doped with a converter material, with a coating being provided on the surface of the detector material in the embodiment according to FIG. 7 a , and a converter material being partially integrated or doped into the interior of the detector material in the embodiment according to FIG. 7 b; [0028] FIG. 8 is a further schematic wiring diagram of a device according to the invention for carrying out the method of the invention for detecting elementary particles, which substantially represents a combination of the illustrations according to FIG. 1 and FIG. 3 ; and [0029] FIG. 9 in an illustration similar to that of FIG. 2 b depicts a section through a modified embodiment of a detector of a device according to the invention. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS [0030] In FIG. 1 , a detector, e.g. a diamond detector, which is supplied via high voltage HV is schematically denoted by 1 , wherein a charging resistor R 3 and a charging capacity C 3 connected to ground via a grounding wire 2 are indicated. Tapping of the signals of the detector 1 is performed on the low-voltage side of the latter via a discharge or signal line 3 . [0031] In FIG. 2 , a supporting plate 4 is schematically indicated, to which a detector element comprising, for instance, a diamond substrate 5 is mounted, wherein contactings of the detector are indicated by 6 in FIG. 2 b. [0032] The fixation of the substrate 5 and a contact 6 to the supporting plate 4 is realized by an adhesive 7 . [0033] In addition, a contact connection to the signal line, which is again denoted by 3 , is indicated via bonding wires 8 in FIGS. 2 a and 2 b. [0034] The supply of the detector 1 is realized similarly as in the embodiment according to FIG. 1 , via a high-voltage supply HV, wherein a charging resistor is again indicated by R 3 and a charging capacity is again indicated by C 3 , the charging capacity C 3 being again connected to earth via a grounding wire 2 . [0035] A further grounding wire provided on the low-voltage side is denoted by 9 in FIG. 2 a. [0036] A signal emitted from the detector 1 reaches an amplification and evaluation unit via signal line 3 as shown in FIG. 3 , wherein, as a function of the frequency or count and/or signal rate as will be discussed in more detail below, an amplification is performed in a first, fast preamplifier 10 and an evaluation is subsequently made in an evaluation unit 11 , such an AC path enabling the detection and processing of individual particles. [0037] The first, fast amplifier 10 is preceded by a capacitor C 1 so as to ensure, by suitable parameters of the capacitor C 1 , that signals will no longer reach the amplifier 10 and the evaluation unit 11 , for instance upon exceeding of a threshold value. [0038] In the same manner, the signal line 3 is coupled to a second, slow amplifier 12 , to which signals are fed by the signal line 3 via an inductance L 1 , wherein an evaluation unit 13 of the signals to be integrated is provided downstream of the second, slow amplifier 12 in a so-called DC path. Similarly, it will be ensured by selecting suitable parameters of the inductance or inductive element L 1 that an amplification by an integration of each of a plurality of signals in the DC path will only be enabled if the number of signals has exceeded a given threshold value. [0039] FIG. 4 depicts a modified embodiment, wherein the first, fast amplifier 10 is again preceded by a capacitor C 1 similarly as in the embodiment according to FIG. 3 . [0040] In the modified embodiment according to FIG. 4 , the amplifier 12 and the evaluation unit 13 are preceded by a low-pass element comprised of a resistor R 1 of a capacity, or a capacitor C 2 , instead of the inductive element provided in FIG. 3 . [0041] The fast, first amplifier 10 may be preceded by a high-pass element instead of the capacitor C 1 preceding the fast, first amplifier 10 , similarly to the low-pass element comprised of elements R 1 and C 2 . [0042] Also in the embodiment according to FIG. 4 , splitting or partitioning of the signals fed via the signal line 3 is effected into an AC path formed by elements 10 and 11 for detecting and evaluating individual pulses or signals and a DC path formed by elements 12 and 13 for integrating each of a plurality of signals or pulses. [0043] In FIG. 5 , it is schematically illustrated how either a separation or subdivision into substantially different measuring ranges or different pulse or signal rate ranges, or a respective overlap, can be achieved by the appropriate selection of the elements preceding the amplifiers 10 and 12 , respectively, with both a detection of individual particles and, at the same time, an integration of each of a plurality, of signals being feasible in the overlapping range. [0044] In the schematic diagram according to FIG. 5 , full lines I and II are each indicated in a frequency or rate range, wherein the measuring of individual signals according to the AC path formed by elements 10 and 11 is performed up to a limiting frequency f 1 , with the sensitiveness for detecting individual signals decreasing subsequently. [0045] The detection of signals each by integrating a plurality thereof according to the DC path formed by elements 12 and 13 is substantially made starting from a frequency or rate f 2 according to full line II. With such a selection of the parameters for the elements preceding the amplifiers 10 and 12 , substantially no detection of signals will thus occur in a subrange lying therebetween. [0046] According to broken lines III, and IV, it is, on the other hand, provided that the detection of individual signals takes place up to a frequency f 3 , while an integration of signals is already effected from a frequency or rate f 4 , which is lower than the frequency or rate f 3 , so that in the overlapping range between rates f 4 and f 3 a detection and evaluation both according to the AC path using elements 10 and 11 and according to the DC path using elements 12 and 13 are performed. [0047] FIGS. 6 a and 6 b schematically illustrate results or wave forms obtainable both by a measurement of individual particles and by integration, an arbitrary unit (a.u.) being each indicated on the ordinate for a measured quantity. [0048] From FIG. 6 a , the detection of individual pulses or signals is clearly apparent, which can each be generated and detected by an individual particle as the latter passes through the detector 1 or impinges on the same, while the illustration according to FIG. 6 b substantially depicts an average over an extended period of time each by detecting and integrating several signals or pulses. [0049] While during the detection of electrically charged particles, the latter trigger or cause electric signals immediately upon entry into or passage through a detector, which electric signals can subsequently be detected and evaluated in the manner described above, it is provided for the detection of uncharged particles that a detector material, which is denoted by 15 in FIG. 7 , is coated with a converter material 16 on one of its surfaces, the direction of an impinging particle or particle flow being indicated by arrow 17 . [0050] Instead of the coating illustrated in FIG. 7 a with a converter material, such a converter material 18 can also be implanted into the detector material 15 , or the detector material 15 can be doped with the same, as is indicated in FIG. 7 b. [0051] In particular as a function of the particles or signals to he determined or detected, it is, moreover, also possible to provide, for instance, a layered structure each comprising layers of a converter material alternating with layers of a detector material. [0052] FIG. 8 is an illustration of a modified embodiment, said illustration substantially combining the illustrations according to FIGS. 1 and 3 such that the reference numerals of said preceding Figures have been retained for identical elements. [0053] From FIG. 8 , it is apparent that tapping of the signals is again effected on the low-voltage side by a detector schematically denoted by 1 via a signal line 3 , wherein, as in the preceding embodiments, amplification, in a first, fast amplifier 10 according to the frequency or count and/or signal rate and subsequently in an evaluation unit 11 according to an AC path are performed for detecting individual particles. [0054] The signal line 3 is again coupled via an inductance L 1 to a second, slow amplifier 12 and an evaluation unit 13 of the signals to be integrated in the so-called DC path. [0055] From FIG. 8 , the support capacitor C 3 is clearly apparent, which has an essential task, in particular at high beam rates. The detector 1 is in each case discharged by ionization, discharging of the detector 1 causing the voltage on the detector 1 to break down and hence the functionality of the detector 1 to be lost. Such discharging is rapidly compensated for by the support capacitor C 3 , with the detector voltage remaining at nominal voltage and, the functionality of the detector I thus being preserved even at high radiation or ionization rates. Such a wiring or arrangement of a support capacitor C 3 is possible with a low-side wiring or a low-voltage-side tap of the signals, as is clearly apparent from FIG. 8 . [0056] A cable 19 possibly having an extremely large length is additionally indicated in FIG. 8 on the high-voltage side HV. Such a cable may lead to a high leakage current, and hence an error source in the detection of the measurement current of the detector, any influence of such a leakage current being again prevented by the low-voltage-side wiring of the measuring electronics, as is clearly apparent from FIG. 8 . [0057] FIG. 9 depicts a modified embodiment of a contact connection of a detector denoted by 21 . In said detector 21 , a detector element, which is again denoted by 5 and, for instance, comprised of diamond, is disposed on a base plate 22 , wherein an intermediate plate 23 and a cover plate 24 are, moreover, indicated in FIG. 9 . [0058] In this embodiment, contacting of the detector element 5 is realized by spring elements 25 formed, for instance, by gold-plated beryllium springs. In this case, a contact pressure is applied purely mechanically by the clamping of the spring elements 25 , while, for instance, in the embodiment illustrated in FIG. 2 b contacting is provided by gluing and/or bonding. [0059] The suitable selection of the dimensions between the individual plate-shaped elements 22 , 23 and 24 ensures the safe clamping, and hence reliable contacting, of the spring-shaped contact element 25 while simultaneously protecting the detector material. [0060] In order to optimize the read-out performance of the detector 1 or 21 , respectively, the former is, for instance, optimized to a wave resistance of 50 ohms. This will result in the optimum adaptation to the input impedance of a preamplifier of likewise 50 ohms, and to the wave resistance of a 50-ohm-cable optionally provided between the detector and the preamplifier. [0061] As a function of the elementary particles to be detected, it may be provided that packets of such particles each comprising more than a single particle are detected. Such packets, which, for instance in a particle accelerator, may comprise an extremely small distance of, e.g., less than 100 ns, in particular about 25 to 50 ns, can each be detected as a packet, wherein pulse heights will, in particular, be summed up in order to enable a statement or assessment as to the overall particle rate. [0062] By enabling both the measurement or detection of individual particles in the processing or treatment of the signals derived from the detector over the AC path formed by elements 10 and 11 and the detection of each of a plurality of particles by an integration of the same, in particular at high rates or frequencies, it has thus become possible to provide an appropriate detection of elementary particles without knowing in advance signal rates to be expected. [0063] Such a detection of elementary particles, for instance, is of special interest in the context of scientific examinations, e.g. in particle accelerators or particle detectors. The option of both detecting individual particles or pulses or signals and integrating the same can, for instance, also be used for measuring the intensity in particle accelerators or similar installations, both for supervision and, for instance, for detecting the actual formation of a particle beam. [0064] In addition, such a detection of individual signals or particles and the substantially simultaneous integration thereof can, for instance, be used in the field of medical technology both for diagnosing and, for instance, for imaging processes, whereby monitoring to avoid overdosing has also become possible. [0065] Similarly, the substantially simultaneous detection and integration of individual particles can also be used in electrical power engineering applications, e.g., in the context of the development of reactors.

Provision is made in a method and a device for detecting elementary particles such as for example protons, ions, electrons, neutrons, photons or the like in a detector, wherein a charge pulse is generated in the detector when a particle passes through the detector and every charge pulse is subsequently converted into an electric signal and the signal is indicated and/or recorded in particular after amplification, for individual signals to be amplified in a first, fast amplifier and/or in each case a plurality of signals to be integrated in a second, slow amplifier, as a result of which it becomes possible for individual particles to be detected and in particular at increased signal or count rates for an integration thereof to be provided.

big_patent

BACKGROUND OF THE INVENTION This invention relates in general to gauging fixtures and in particular to an apparatus for automatically spin checking driven disc assemblies adapted for use in friction clutches. Clutches are well known devices which are frequently employed in vehicles to selectively connect a source of rotational power, such as the crankshaft of an engine, to a driven mechanism, such as a transmission. Typically, a cover of the clutch is connected to a flywheel carried on the end of the engine crankshaft for rotation therewith. Between the flywheel and the clutch cover, a pressure plate is disposed. The pressure plate is connected for rotation with the flywheel and the cover, but is permitted to move axially relative thereto. A shift lever assembly is provided for selectively moving the pressure plate back and forth in the axial direction. The shift lever assembly is usually operated by a driver of the vehicle by means of a foot actuated pedal. A driven disc assembly is disposed within the clutch between the pressure plate and the flywheel. The driven disc assembly is carried on an output shaft of the clutch, which forms the input to the transmission. The driven disc assembly includes a hub, which is splined onto the output shaft, and a support plate which is mounted on the hub for limited rotational movement. A plurality of friction elements are usually secured to the outer ends of the support plate. Springs or similar torsion dampening devices may be provided between the support plate and the hub. When the pressure plate is moved toward the flywheel, the friction elements of the support plate are frictionally engaged therebetween so as to cause the output shaft of the clutch to rotate with the flywheel, the cover, and the pressure plate. When the pressure plate is moved away from the flywheel, the driven disc assembly is released from such frictional engagement so as to disconnect this driving connection. The length of travel of the pressure plate between the engaged and disengaged positions is typically rather small, typically from 0.050 inch to 0.100 of an inch. Accordingly, the driven disc assembly (which is selectively engaged and disengaged by the pressure plate) must be manufactured to have a thickness which is within closely maintained tolerances. Furthermore, the driven disc assembly must not be excessively warped or otherwise non-planar in shape. Otherwise, the pressure plate may undesirably contact the driven disc assembly when moved to the disengaged position. In the past, a test fixture has been provided for measuring the amount of warpage of a driven disc assembly, referred to as spin checking the assembly. This prior test fixture included a splined hub, upon which the driven disc assembly to be tested was mounted, disposed between a stationary ring and a movable ring. After the driven disc was installed, a pneumatic cylinder was actuated to move the movable ring toward the stationary ring such that the driven disc assembly was frictionally engaged therebetween. This movement initially positioned the two rings apart from one another by a distance which was equal to the thickness of the driven disc assembly. Then, the movable ring was retracted a predetermined distance from this initial position using a mechanical shim. This predetermined additional distance represented the maximum amount of warpage which could be tolerated for the particular driven disc assembly. Next, a predetermined amount of torque was applied to the hub to rotate the driven disc assembly relative to the rings. This torque was generated by means of a weight supported at the end of a pendulum connected to the hub. If the driven disc assembly was able to rotate under the urging of this applied torque, then the amount of warpage was within acceptable tolerances. However, if the driven disc assembly was not able to rotate under the urging of this applied torque, then the warpage of the driven disc assembly was beyond acceptable tolerances. Although this prior test fixture has been found to function satisfactorily, it will be appreciated that it was somewhat slow and, therefore, inefficient in the production environment. Furthermore, it required several manual operations to be performed by an operator. Lastly, other than the inability of the driven disc assembly to rotate under the urging of the applied torque, the fixture generated no external indication of whether the tested assembly was good or bad. Thus, it would be desirable to provide an improved spin checking apparatus which automatically determines whether the driven disc assembly is good or bad and which generates an external indication to the operator of the test results. SUMMARY OF THE INVENTION This invention relates to an improved apparatus for automatically spin checking a driven disc assembly. The apparatus includes an enclosure having a stationary ring mounted thereon and a movable ring slidably supported thereon. A torque motor is provided with an output shaft connected to a splined hub, upon which the driven disc assembly is mounted for rotation between the two rings. Means are provided for selectively moving the movable ring toward the stationary ring so as to frictionally engage the driven disc assembly therebetween. When so engaged, the distance separating the two rings is measured by an electronic sensor. The torque motor is then energized to exert a predetermined torque on the driven disc assembly, attempting to rotate it against the frictional force generated by the rings. Next, the movable ring is gradually moved away from the stationary ring so as to gradually reduce the frictional force exerted on the driven disc assembly. When the frictional force has decreased a sufficient amount, the driven disc assembly will begin to rotate under the urging of the torque motor. Means are provided for sensing this rotation and for measuring the distance separating the two rings at that time. The difference between these two distances is compared with a standard value to determine if the driven disc assembly is excessively warped. It is an object of this invention to provide an improved apparatus for spin checking a driven disc assembly. It is another object of this invention to provide such a spin checking apparatus which operates automatically without manual involvement by an operator. It is a further object of this invention to provide such a spin checking machine which generates an external indication to the operator of whether the driven disc assembly is good or bad. Other objects and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiment, when read in light of the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view, partially in cross section, of an automatic spin checking apparatus in accordance with this invention, the apparatus being shown in an opened position. FIG. 2 is a side elevational view similar to FIG. 1 showing a driven disc assembly installed in the spin checking apparatus. FIG. 3 is a side elevational view similar to FIG. 2 showing the spin checking apparatus in a closed position. FIG. 4 is a block diagram of the control system for the spin checking apparatus illustrated in FIGS. 1 through 3. FIG. 5 is a flow chart showing the sequence of operations performed by the microprocessor illustrated in FIG. 4. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, there is illustrated in FIG. 1 an automatic spin checking apparatus, indicated generally at 10, in accordance with this invention. The apparatus 10 includes a base 11 having a rigid test enclosure secured thereto. The test enclosure includes an upstanding left end plate 12 and an upstanding right end plate 13. The end plates 12 and 13 are rigidly secured to the base 11 by respective left and right pairs of end plate brackets 15 and 16 (only one of each of the end plate bracket pairs 15 and 16 is illustrated). A top plate 17 is connected between the upper ends of the end plates 12 and 13. Also, a plurality of cylindrical shafts 18 (only one is illustrated) is connected between the end plates 12 and 13. The base 11, the end plates 12 and 13, the end plate brackets 15 and 16, and the top plate 17 form the rigid test enclosure for the apparatus 10. The function of the shafts 18 will be explained below. A pair of rings 20 and 21 are provided within the test enclosure. The left ring 20 is secured to the left end plate 12 and, therefore, is immobile. The right ring 21 is secured to a support plate 22. The support plate 22 has a plurality of apertures (not shown) formed therethrough for receiving the shafts 18. Thus, the support plate 22 (and the right ring 21 secured thereon) is journalled for sliding movement on the shafts 18 toward and away from the left end plate 12 (and the left ring 20 secured thereto). The support plate 22 is connected to a transfer bar 23 which extends through an opening 13a formed through the right end plate 13. The transfer bar 23 is connected to a nut 25 carried on a precision ball screw shaft 26. The ends of the ball screw shaft 26 are rotatably supported in left and right bearings 27 and 28. The bearings 27 and 28 are supported on a bearing bracket assembly 30 secured to the base 11. The right end of the ball screw shaft 26 extends through the right bearing 28 into engagement with a coupling 31. The coupling 31 is connected to the output shaft 32a of a bi-directional servo motor 32. The servo motor 32 is supported on a motor bracket assembly 33 connected to the base 11. The servo motor 32 is conventional in the art and is adapted to be energized to rotate the output shaft 32a (and the ball screw shaft 26 connected thereto) in either of two rotational directions. When the ball screw shaft 26 is rotated in a first rotational direction, the nut 25 is moved toward the right. As a result, the transfer bar 23, the support plate 22, and the right ring 21 are all moved toward the right as a unit. Similarly, when the ball screw shaft 26 is rotated in a second rotational direction, the nut 25, the transfer bar 23, the support plate 22, and the right ring 21 are all moved toward the left as a unit. As is known in the art, the servo motor 32 may include an internal sensor 34 (schematically shown in FIG. 4) which generates an electrical signal when the rotation of the output shaft 32a is prevented, even though the servo motor 32 is energized, as will be explained below. An electronic position sensor 35 is secured to the stationary left end plate 12, while a target 36 is secured to the movable support plate 22. The position sensor 35 is conventional in the art and is adapted to generate an electrical signal which is representative of the distance from the sensor 35 to the target 36. As mentioned above, the left ring 20 is secured to the stationary left end plate 12, while the right ring 21 is secured to the support plate 22 for movement therewith. Thus, it can be seen that the electrical signal generated by the sensor 35 is also representative of the distance from the left ring 20 to the right ring 21. The purpose of this signal will be explained below. Referring to the left portion of the apparatus 10, a generally hollow cylindrical mounting bracket 40 is secured to the left end plate 12. A torque motor 41 having a rotatable output shaft 41a is connected to the mounting bracket 40. The right end of the output shaft 41a extends through the bracket 40 into engagement with a spindle 42 which is rotatably supported in the left end plate 12 by a bearing 43. A key or similar means is provided for connecting the output shaft 41a of the torque motor 41 to the spindle 42 for rotation therewith. The spindle 42 is further connected to an externally splined hub 45 for rotation therewith. The hub 45 is located within the rigid test enclosure generally within the opening defined by the left ring 20. The torque motor 41 is conventional in the art and is adapted to exert a predetermined amount of torque on the output shaft 41a when energized. The left end of the output shaft 41a is connected through a coupling 46 to an optical encoder 47. The encoder 47 is supported on an encoder bracket assembly 48 secured to the base 11. The encoder 47 is conventional in the art and generates an electrical signal which is representative of the direction and magnitude of rotation of the output shaft 41a. The apparatus 10 is illustrated in FIG. 1 in an opened position, wherein the right ring 21, the support plate 22, and the transfer bar 23 are moved to the right, away from the left ring 20. In this position, a driven disc assembly, indicated generally at 50, may be installed on the hub 45, as shown in FIG. 2. The driven disc assembly 50 includes a central member 51 having an opening formed therein which is internally splined. The internal splines of the central member 51 cooperate with the externally splined hub 45 to prevent relative rotation therebetween. The driven disc assembly 50 further includes an outer member 52 supported on the central member 51. The outer portions of the outer member 52 extend between the aligned portions of the left and right rings 20 and 21. Thus, when the right ring 21, the support plate 22, and the transfer bar 23 are subsequently moved to the closed position (toward the left) as shown in FIG. 3, the outer portions of the outer member 52 are frictionally engaged between the left and right rings 20 and 21. Referring now to FIG. 4, there is illustrated a block diagram of a control system, indicated generally at 55, for the spin checking apparatus 10 thus far described. The control system 55 includes a microprocessor 56 or similar electronic controller having inputs which are connected to the optical encoder 47, the position sensor 35, and the sensor portion of the servo motor 32. A plurality of manually operable control switches 57 are also connected to the inputs of the microprocessor 56. The control switches 57 permit an operator of the apparatus to control the operation thereof. In response to these signals, the microprocessor 56 controls the operation of the torque motor 41 and the servo motor 32. The microprocessor 56 also generates signals to a conventional display 58 to provide the operator of the apparatus 10 with a visual indication of the status thereof. Referring now to FIG. 5, there is illustrated a flow chart showing the basic program executed by the microprocessor 56 during operation of the spin checking apparatus 10. After the driven disc assembly 50 to be tested is installed on the hub 45 as shown in FIG. 2, the operator actuates one of the control switches 57 to generate a start signal to the microprocessor 56. The program initially enters an instruction 60, wherein the microprocessor 56 reads the signals (if any) generated by the control switches 57. The program next enters a decision point 61, wherein it is determined whether a start signal has been generated by the operator of the apparatus 10. If the start signal has not been generated, the program branches back to the instruction 60. The microprocessor 56 may be programmed to respond to other signals generated by the control switches 57. Thus, the microprocessor 56 repeatedly reads the values of the control switches 57 until the start signal has been generated. When the start signal is generated, the program branches from the decision point 61 to an instruction 62, wherein the microprocessor 56 actuates the servo motor 32 to rotate the ball screw shaft 26 at a relatively fast speed in a first rotational direction. As a result, the transfer bar 23, the support plate 22, and the right ring 21 are rapidly moved toward the left. Such rapid movement continues until the outer member 52 of the driven disc assembly 50 is frictionally engaged between the left and right rings 20 and 21. At that point, the servo motor 32 is de-actuated. To accomplish this, the program next enters an instruction 63, wherein the value of the signal from the sensor portion 34 of the servo motor 32 is read. As previously mentioned, the sensor portion 34 of the servo motor 32 generates a signal when rotation of the output shaft 32a is prevented. This would occur when the right ring 21 frictionally engages the driven disc assembly 50. The program next enters a decision point 64, wherein it is determined if the sensor portion 34 of the servo motor 32 is generating the signal indicating that the right ring 21 has frictionally engaged the driven disc assembly 50. If not, the program branches back to the instruction 63 to re-read the value of the signal from the sensor portion 34 of the servo motor 32. Thus, the program will continuously read the value of this signal until it is generated, indicating that the right ring 21 has frictionally engaged the driven disc assembly 50. When such frictional engagement occurs, the program will branch from the decision point 64 to an instruction 65, wherein the microprocessor 56 discontinues the actuation of the servo motor 32. The program next enters an instruction 66, wherein the microprocessor 56 reads the value of the signal generated by the position sensor 35. As mentioned above, the value of this signal is representative of the distance between the left and right rings 20 and 21. The program next enters an instruction 67, wherein the microprocessor 56 reads the initial value of the signal generated by the optical encoder 47. This signal represents the starting position of the output shaft 41a of the torque motor 41. Having made the initial measurements of the distance separating the rings 20 and 21 and the starting position of the torque motor output shaft 41a, the program next enters an instruction 68, wherein the microprocessor 56 actuates the torque motor 41. As mentioned above, the torque motor 41 exerts a predetermined amount of torque (preferably about four inch-pounds) on the output shaft 41a when energized, thus tending to rotate the hub 45 and the driven disc assembly 50 mounted thereon. However, since the driven disc assembly 50 is frictionally engaged between the left and right rings 20 and 21, such rotation is initially prevented. Next, the program nexts enters an instruction 69, wherein the microprocessor 56 actuates the servo motor 32 to rotate the ball screw shaft 26 at a relatively slow speed in a second rotational direction. As a result, the transfer bar 23, the support plate 22, and the right ring 21 are moved gradually toward the right. It has been found satisfactory to rotate the ball screw shaft 26 at such a rotational speed that the right ring 21 is moved away from the left ring 20 at a speed of about 0.002 inch/second. As the right ring 21 is moved toward the right (away from the stationary left ring 20), the frictional engagement of the driven disc assembly 50 is gradually reduced. At some point, the torque exerted on the driven disc assembly 50 by the torque motor 41 will exceed the frictional force generated by the engagement of the rings 20 and 21. When this occurs, the driven disc assembly 50 will begin to rotate relative to the rings 20 and 21. When a predetermined amount of rotation has occurred (typically about ten degrees), it is assumed that the driven disc assembly 50 is completely free from the frictional engagement of the rings 20 and 21. To accomplish this, the program enters an instruction 70, wherein the microprocessor 56 reads the current value of the signal generated by the optical encoder 47. As discussed above, this value is representative of the rotational position of the output shaft 41a and, therefore, the rotational position of the driven disc assembly 50 splined thereon. The program then enters an instruction 71, wherein the current value of the optical encoder signal is subtracted from the initial value of such signal to generate a difference signal. This difference signal represents the amount that the driven disc assembly 50 has rotated from its initial position. The program enters a decision point 72, wherein this difference signal is compared to the ten degree standard value. If the difference signal is less than this standard value, the program branches back to the instruction 70, wherein the next current value of the optical encoder signal is read. Thus, the program will continuously read the optical encoder signal and compare it with the ten degree standard until the driven disc assembly 50 has rotated at least ten degrees from its original position. At that time, the program branches from the decision point 72 to an instruction 73, wherein the current value of the position sensor signal is read. The program next enter an instruction 74, wherein the current value of the position sensor signal is subtracted from the initial position sensor signal. This difference signal represents the amount of distance which the right ring 21 was required to be moved before the frictional engagement of the driven disc assembly 50 was released. Consequently, the difference signal is also representative of the amount of warpage in the driven disc assembly 50. The program next enters a decision point 75, wherein the value of the position sensor difference signal is compared with a standard value, which represents the maximum allowable warpage in the driven disc assembly. If the difference signal is less than this standard value, the warpage (if any) of the driven disc assembly 50 is within specified tolerances. Accordingly, the program branches to an instruction 76, wherein the microprocessor 56 actuates the servo motor 32 to rotate the ball screw shaft 26 at a relatively fast speed in the second rotational direction. This rapidly moves the right ring 21 toward the right, allowing the operator to remove the driven disc assembly 50 and install another such assembly for testing. If the difference signal is greater than the standard value, the warpage of the driven disc assembly 50 is beyond specified tolerances. Accordingly, the program branches to an instruction 77, wherein the microprocessor 56 de-actuates the servo motor 32 to halt further movement of the right ring 21. As a result, the operator must manually acknowledge (by means of one of the control switches 57) that the driven disc assembly is defective. When such acknowledgement is made, the microprocessor 56 actuates the servo motor 32 to rotate the ball screw shaft 26 at a relatively fast speed in the second rotational direction to permit removal of the defective assembly 50. At the same time, the microprocessor 56 can actuate the display 58 to generate a visible alert to the operator that the assembly 50 is defective. Thus, it can be seen that the apparatus 10 automatically determines whether the assembly 50 is within specified tolerances. Furthermore, the apparatus 10 generates external indications to the operator of the condition of the tested assembly 50, thereby minimizing the chances of operator error. Since specific measurements are taken for each assembly 50 being tested, such measurements can be easily stored in the microprocessor 56 and used for statistical process control. In accordance with the provisions of the patent statutes, the principle and mode of operation of this invention have been explained and illustrated in its preferred embodiment. However, it must be understood that this invention may be practiced otherwise than as specifically explained and illustrated without departing from its spirit or scope.

An apparatus for automatically spin checking a driven disc assembly for warpage includes a stationary ring and a movable ring. A torque motor is provided with an output shaft connected to a splined hub, upon which the driven disc assembly is mounted for rotation between the two rings. A servo motor and ball srew mechanism selectively moves the movable ring toward the stationary ring so as to frictionally engage the driven disc assembly therebetween. When so engaged, the distance separating the two rings is measured by an electronic sensor. The torque motor is then energized to exert a predetermined torque on the driven disc assembly, attempting to rotate it against the frictional force generated by the rings. Next, the movable ring is gradually moved away from the stationary ring so as to gradually reduce the frictional force exerted on the driven disc assembly. When the frictional force has decreased a sufficient amount, the driven disc assembly will begin to rotate under the urging of the torque motor. Sensors are provided for sensing this rotation and for measuring the distance separating the two rings at that time. The difference between these two distances is compared with a standard value to determine if the driven disc assembly is excessively warped.

big_patent

RELATED APPLICATION DATA This application claims the benefit of priority of U.S. Provisional Patent Application Ser. No. 61/744,917, filed on Oct. 5, 2012, and titled “Contourlet Appearance Model”, which is incorporated by reference herein in its entirety. STATEMENT OF GOVERNMENT INTEREST Subject matter of this disclosure was made with government support under Army Research Office grants DAAD19-02-1-0389 and W911NF-09-1-0273. The government may have certain rights in this subject matter. FIELD OF THE INVENTION The present invention generally relates to the field of image processing. In particular, the present invention is directed to face age-estimation and methods, systems, and software therefor. BACKGROUND Face recognition is one of the most difficult and challenging tasks in computer vision, partly because of large variations in human faces. Difficulty and challenge is even higher for face age-estimation. Researchers have been developing technologies for face age-estimation due to the demands of many real-world operating scenarios that require accurate, efficient, uncooperative, and cost-effective solutions, such as automated control and surveillance systems. Accurate age-estimation may be of great benefit to businesses, such as convenience stores, restaurants, and others, who are required to forbid underage access to, for example, alcohol or tobacco. Age-estimation systems can also be applicable in homeland security technologies, criminal identification, management of e-documents and electronic customer relationships, all without requiring imposing password prompts, password change reminders, etc. In restaurants and other businesses, age-recognition systems may be used help to identify trends in business relative to the ages of customers. Additionally, these systems can help to prevent children from viewing or otherwise consuming unacceptable media or programming and can even be used to thwart underage people from driving cars before they reach a legal driving age. Aging of human faces is a complicated process influenced by many factors such as gender, ethnicity, heredity factors and environmental factors, including cosmetic interventions, societal pressure, relative sun exposure, and drug or alcohol consumption. In this process, there are some controllable factors (i.e., gender, ethnicity, heredity, etc.) that can be exploited in order to recognize trends in the aging of human faces. However, other uncontrollable factors, such as environment, living styles, and sun exposure (photoaging), can prove quite challenging to deal with. Therefore, correctly estimating an age from a face is a huge challenge even for humans, let alone for computing devices. The effects of age on the human face has been studied in numerous research fields, including orthodontics, anthropology, anatomy, forensic art, and cognitive psychology. However, compared to these aging-related fields, computer science approaches for aging problems are relatively new. From the viewpoint of computer science, face aging technologies generally address two areas: face age-estimation and face age-progression. The face age-estimation problem can be addressed with computer software that has the ability to recognize the ages of individuals in a given photo. Meanwhile, the face age-progression problem has the ability to predict the future faces of an individual in a given photo. To achieve an accurate, efficient, uncooperative, and cost-effective solution to the problem of face age-estimation, it becomes necessary to extract as much unique information as possible from each image in question and to use such information in an exhaustive comparison. However, these methods are known to be computationally expensive and may require special tweaking in order to generate meaningful results. More accurate and efficient face recognition methods are desired in numerous applications, including those discussed above, which demand near real-time computation and do not require user cooperation. SUMMARY OF THE DISCLOSURE It is understood that the scope of the present invention is limited to the scope provided by the independent claims, and it is also understood that the scope of the present invention is not limited to: (i) the dependent claims, (ii) the detailed description of the non-limiting embodiments, (iii) the summary, (iv) the abstract, and/or (v) description provided outside of this document (that is, outside of the instant application as filed, as prosecuted, and/or as granted). In one implementation, the present disclosure is directed to a method of generating a face age-estimation for a face represented by first image data as a function of faces represented by second image data and having assigned landmark points and known ages. The method includes receiving, by a face age-estimation system, the first image data; applying, by the face age-estimation system, a contourlet appearance model (CAM) algorithm to the first image data so as to generate a first feature vector; executing, by the face age-estimation system, an age classifier on the first feature vector so as to identify an estimated age group for the face represented by the first image data as a function of the assigned landmark points of the second image data; and applying, by the face age-estimation system, an aging function to the first feature vector so as to generate the face age-estimation as a function of the assigned landmark points of the second image data. In another implementation, the present disclosure is directed to a method of face age-estimation. The method includes extracting, by a feature extractor, facial features from an image of a test subject; and mapping, by a feature-space-to-age-space mapping unit, the facial features to one of at least two differing age groups having corresponding differently calibrated mapping functions. In yet another implementation, a machine-readable storage medium containing machine executable instructions for performing a method of generating a face age-estimation for a face represented by first image data as a function of faces represented by second image data and having assigned landmark points and known ages. The machine-executable instructions include a first set of machine-executable instructions for receiving the first image data; a second set of machine-executable instructions for applying a contourlet appearance model (CAM) algorithm to the first image data so as to generate a first feature vector; a third set of machine-executable instructions for executing an age classifier on the first feature vector so as to identify an estimated age group for the face represented by the first image data as a function of the assigned landmark points of the second image data; and a fourth set of machine-executable instructions for applying an aging function to the first feature vector so as to generate the face age-estimation as a function of the assigned landmark points of the second image data. In still yet another implementation, a machine-readable storage medium containing machine executable instructions for performing a method of face age-estimation. The machine-executable instructions include a first set of machine-executable instructions for extracting facial features from an image of a test subject; and a second set of machine-executable instructions for mapping the facial features to one of at least two differing age groups having corresponding differently calibrated mapping functions. These and other aspects and features of non-limiting embodiments of the present invention will become apparent to those skilled in the art upon review of the following description of specific non-limiting embodiments of the invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS For the purpose of illustrating the invention, the drawings show aspects of one or more embodiments of the invention. However, it should be understood that the present invention is not limited to the precise arrangements and instrumentalities shown in the drawings, wherein: FIG. 1A is a diagrammatic representation illustrating a face age-estimation training system and a corresponding method of face age-estimation training; FIG. 1B is a diagrammatic representation illustrating a face age-estimation system and a corresponding method of face age-estimation; FIG. 2 is a photograph of a face with landmarks assigned in accordance with the present disclosure; FIG. 3 contain visual representations of various feature extraction algorithms, including algorithms used in an exemplary embodiment of the present invention; and FIG. 4 is a diagram illustrating a computing system that can implement methods of the present disclosure and/or various portions of such methods. The drawings are not necessarily to scale and may be illustrated by phantom lines, diagrammatic representations and fragmentary views. In certain instances, details that are not necessary for an understanding of the embodiments or that render other details difficult to perceive may have been omitted. DETAILED DESCRIPTION At a high level, aspects of the present disclosure are directed to methods and software that include steps and/or machine-readable instructions for estimating an age of a person represented in first image data (e.g., a digital or digitized photograph or other visual image). The present inventors have discovered that verification rates for image-based face age-estimation can be greatly improved by performing a contourlet transform on the first image data and by classifying the subject face according to aging mechanisms. In one embodiment, a subject face is classified as younger or older before performing face age-estimation. Younger and older people have fundamentally different aging mechanisms, such that at least two aging functions can be constructed, though it will be appreciated that three or more aging functions, each corresponding to a different aging period, such as early childhood, adolescence, middle age, or senior, among others, could be used. Referring now to the drawings, FIG. 1A illustrates components of a face age-estimation training method 100 according to an embodiment of the invention, while FIG. 1B illustrates components of a face age-estimation method 150 according to an exemplary embodiment of the present invention. Face age-estimation training method 100 and face-age estimation method 150 may be implemented by face age-estimation systems, which may be implemented by any one or more computing devices that generally are: 1) programmed with instructions for performing steps of a method of the present disclosure; 2) capable of receiving and/or storing data necessary to execute such steps; and 3) capable of providing any user interface that may be needed for a user to interact with the system, including setting the system up for an age-estimation session and estimation results, among other things. Those skilled in the art will readily appreciate that an age-estimation system of the present disclosure can range from a self-contained device, such as a smartphone, tablet computer, laptop computer, desktop computer, sever, web-server, to a network of two or more of any of these devices. Fundamentally, there is no limitation on the physical construct of an age-estimation system, as long as it can provide the features and functionality described herein. For illustrative purposes, FIG. 4 , which is described more fully below, represents an exemplary computing system 400 that can be used to implement various steps of methods 100 and 150 and any other method incorporating features/functionality disclosed herein. It is noted that when the relevant software is combined with suitable hardware for executing the software and implementing the functionality embodied in the software, the combination of the hardware with the controlling software becomes a system having the corresponding functionality. For example, when method 150 is performed by a suitable computing system, such as computing system 400 , the resulting combination of hardware and controlling software may be considered to form an age-estimation system that may receive image data containing data representing a face and generate an estimated age based on that data. Likewise, when software instructions for performing any subset of functionality within a particular method is combined with executing hardware, the combination of the hardware and controlling software effectively becomes a machine for carrying out the relevant functionality. For example, software for extracting facial features from an image, when executed on suitable hardware, becomes a feature extractor. Other functional components under this scheme include, but are not limited to a feature-space-to-age-space mapping unit, a classifier, a support vector machine, an age-training module, a contourlet appearance model processor, and a support vector regression processor, among others. Those skilled in the art will readily understand the combination of software and hardware necessary to create these functional components. It is noted that while these functional components may often be embodied using a single general-purpose processor or set of such processors, alternative systems can be constructed using discrete physical components executing suitable software and/or having circuitry physically configured for providing the requisite functionality or portion(s) thereof. Typically, the first image data received represents an image of one or more persons' faces for which ages are desired to be estimated. Those skilled in the art will readily appreciate that the image data will typically be utilized by methods 100 and 150 in the form of a digital image contained in a suitable image file, such as a JPG file, a GIF file, a PNG file, a TIFF file, or a RAW file, among others. Consequently, the term “image” and like terms as used herein refer not only to a print image, an electronically rendered image, etc., but also to the image-defining content of 1) a digital image file, 2) a signal, 3) a digital memory, or 4) other medium containing that information. Image data may be stored in an age-estimation system using an appropriate computer storage system (see, e.g., FIG. 4 ). Image data may be received from a database, through the Internet, from a security camera, and/or in any other manner known in the art to be suitable for providing image data. In one embodiment, image data may represent a single 2D image of front view of a subject's face, while, in other embodiments, further processing may be necessary to address issues such as side views of faces, tilted faces, etc., as is known in the art. In FIG. 1A , method of face age-estimation training 100 begins with a database of second image data 104 comprising faces having a number of assigned landmark points, which may be of any number and may be advantageously assigned in a specific anthropometric order. See, for example, FIG. 2 , which illustrates a photograph 200 of a face 204 with 68 assigned landmark points 208 , with points 0 - 14 being landmark points for the outside contour of a face, points 15 - 20 being landmark points for the right eyebrow, points 21 - 26 being landmark points for the left eyebrow, other points being landmark points for eye outlines, iris outlines, nose outlines, nose center, nostrils, lip outlines, top lip and bottom lip outlines, etc. Referring back to FIG. 1A , a feature extraction algorithm, in this embodiment a contourlet appearance model (CAM) algorithm 106 , may be used to extract feature vectors x 108 from face images I represented in second image data 104 . A CAM is an appropriate method for modeling the complexities of an aging face, because it can represent both the shape structure of a face and its constituent parts, for example, nose, lips, lower face, as well as the texture of the face. A CAM is a combination of shape variation, which is a primary factor in the growth and development period of young people, and texture variation, which can often be a more relevant factor in estimating the age of older persons. A CAM is used as a statistical model of appearance and is generated by combining a modified active shape model (MASM) that represent the facial structure and a quasi-localized texture model that represents the pattern of contourlet-based intensities (skin texture) across a facial image patch. Compared to other facial feature extraction methods, such as local binary patterns (LBP) and Gabor wavelet transforms, a CAM has the ability to extract more robust facial features that encode age information. In addition, a CAM is robust against noise (as shown, for example, in FIG. 3 ), because it can distinguish noise ( FIG. 3 f ) from meaningful signals (e.g., FIGS. 3 d -3 e ) in a given noisy image ( FIG. 3 c ). FIG. 3 illustrates features extracted by different texture extraction methods: (a) an original facial image; (b) a noisy image with standard deviation of noise σ set to 0.1; (c)-(f) images illustrating low-pass, strong edge, weak edge and noise components, respectively, obtained after applying a logarithmic nonsubsampled contourlet transform (LNSCT) on the noisy image; (g) an LBP map of the noisy image; and (h) a noisy image filtered using a Gabor filter. A CAM can be decomposed into two models: the MASM shape model x (such as in Equation 1, below) and the contourlet texture model g (such as in Equation 2, below). A CAM has three main processing steps: first, given a training set of second, landmarked images 104 , an MASM may be generated to model the shape variation in the images; then, a statistical principal component analysis (PCA) model of the contourlet-level appearance may be built; and finally, a CAM may be generated by applying a further statistical PCA approach to the shape and appearance parameters. The contourlet-level appearance may be generated as follows: 1) apply appearance alignment by warping the control points to match the mean shape by using the Delaunay triangulation algorithm or other suitable algorithm for warping control points; 2) correct the lighting of gray-level appearance; and 3) apply non-subsample contourlet transform on the gray-level appearance to obtain weak edge texture vectors ( FIG. 3 e ). Then, both the gray-level (from image) and weak edges texture (from contourlet texture) are used to model the contourlet-level appearance. A statistical PCA model may be applied in order to obtain a linear model (Equations 2 and 3, wherein g and w are the mean normalized gray-level and weak edge texture vectors, Φ g and Φ w are a set of orthogonal models of variations, and b g and b w are sets of facial texture parameters) for the extracted appearances. {circumflex over (x)}= x +Φ s b s   (Equation 1) g=g g +Φ g b   (Equation 2) w= w +Φ w b   (Equation 3) To correct the lighting of gray-level appearance, a first variable may be initialized to the first gray level sample g 1 of images I, then, for each of the other gray level samples, g 2 -g N : the inner product of the first variable with the current gray level sample may be calculated and assigned to a second variable; then, the inner product of the current gray level sample and 1 may be calculated and divided by the number of elements in the vectors and the result may be assigned to a third variable; and, finally, the current gray level sample may be normalized by calculating the difference between the current gray level sample and the inner product of the third variable and 1, then dividing the result by the second variable. The normalized gray level samples may replace the original gray level samples or may be saved in a separate location. Since there may be correlations between the shape and contourlet-level variations, a further statistical PCA approach may be applied to the data as follows: for each feature vector, a concatenated vector can be generated as in Equation 4, wherein W s is a diagonal matrix of weights for each shape parameter, allowing for the difference in units between the shape and gray models, and P S T , P w T and P g T are the constructed orthogonal subspaces of shape, contourlet texture and gray-level, respectively, which are strongly related to Φ S and Φ w in Equations 2 and 3. All three components b s , b w and b g contribute to modeling a face at different levels; by combining these, it is possible to represent faces uniquely. b = ( W S ⁢ b S W w ⁢ b w W g ⁢ b g ) = ( W S ⁢ P S T ⁡ ( x - x _ ) W w ⁢ P w T ⁡ ( w - w _ ) W g ⁢ P g T ⁡ ( g - g _ ) ) ( Equation ⁢ ⁢ 4 ) By applying a PCA model on the vectors in Equation 4, a further model can be generated, as shown in Equation 5, wherein Q represents the eigenvectors generated through PCA and c is a vector of appearance parameters controlling both the shape and gray-levels of the model. Note that because the shape and gray-model parameters have been normalized, they will have a zero mean, and, as such, so will c. b≈Qc  (Equation 5) The CAM result, b, encodes correlations between the parameters of the shape model and those of the texture model across the training set. The final training images can be represented according to Equation 6, wherein X i represents the shape or texture of a training image I i , X is the mean of the training images' parameters, P is the eigenvector matrix generated by the training procedure, and x i is a vector of weights referred to as a feature vector. x, is equivalent to c in Equation 5. X i = X +Px i   (Equation 6) During the training procedure, feature vectors x 108 may be extracted from second image data 104 representing face images I. In FIG. 1A : N refers to the total number of training images, for example, the number that have faces ranging in ages from infant to sixty-nine years; N 1 refers to the number of youth training face feature vectors 112 generated from youth training faces ranging in age from infant (0 years) to, for example, 20 years (babies, children, teens and young adults); and N 2 refers to the number of adult training face feature vectors 116 generated from adult training faces ranging in ages from, for example, 21 years to, for example, 69 years (adults). As such, N=N 1 +N 2 . Note that the specific cut-off years (here, 20, 69) may be modified and/or their number (i.e., the number of age groupings) may be increased, resulting in, for example, more than one aging function, more than one growth-development function, and more than one age classifier. Feature vectors x may serve as inputs to an age classifier and two aging functions. There are two main steps in the classification module: first, Support Vector Regression 118 , 122 may be used on the youth training face feature vectors 112 and adult training face feature vectors 116 to construct two differently-calibrated aging functions, a growth and development mapping function ƒ 1 (x) 120 and an adult aging mapping function ƒ 2 (x) 124 , respectively. Then, support vector machines 126 are used on both the youth training face feature vectors 112 and adult training face feature vectors 116 in order to build an age classifier ƒ(x) 128 , which, in an embodiment, is capable of distinguish between youths (ranging in ages from infant to 20) and adults (ranging in ages from 21 to 69), though in other embodiments it may be made to distinguish between three or more age groups. Given N training points (x 1 , y 1 ), (x 2 , y 2 ), . . . , (x N , y N ) with x i εR n and y i ε{−1,1}, i=1, . . . , N and supposing that these points are linearly separable, we have to find a set of N s support vectors s i (N s ≦N), coefficient weights a i , a constant b and the linear decision surface. Equation 7 results in the distance to the support vectors being maximized, wherein w is defined according to Equation 8. w·x+b= 0  (Equation 7) w=Σ i=1 N s α i y i s i   (Equation 8) SVMs can be extended to nonlinear decision surfaces by first using a mapping function Φ to map these points to some other Euclid space H that is linearly separable, with the given regularization parameter C>0, Φ: R n |→H. Secondly, a kernel function K may be defined, where K(x i , x j )=Φ(x i )●Φ(x j ), x i and x j being image samples and Φ being the mapping function, then the nonlinear decision surface may be defined according to Equation 9, wherein a i and b are the optimal solution of quadratic programming (QP) according to Equations 10 and 11. Σ i=1 N s α i y i K ( s i ,x )+ b= 0  (Equation 9) min w,b,ξ ½ ∥w∥ 2 CΣ i−1 N s ξ i   (Equation 10) y i ( w,x i b )≧1−ξ i with Σ i ≧0  (Equation 11) A goal in SVR is to build a hyper-plane as close to as many of the training points as possible. Given N training points (x 1 , y 1 ), (x 2 , y 2 ), . . . , (x N , y N ) with x i εR n and y i εR, i=1, . . . , N, a hyper-plane can be constructed along with the values of w and b. The hyper-plane w may be selected with a small norm while simultaneously minimizing the sum of the distances from these points to the hyper-plane, measured by using Vapnik's ε-insensitive loss function, as shown in Equation 12.  y i - ( w . x i + b )  ɛ = { 0 if ⁢  y i - ( w . x i + b )  ≤ ɛ  y i - ( w . x i + b )  - ɛ otherwise ( Equation ⁢ ⁢ 12 ) In Equation 12, the value of & may be selected by the user, and the trade-off for finding a hyper-plane with good regression performance may be controlled via the given regularization parameter C, which may be determined empirically depending on design requirements. The QP problem associated with SVR is given by Equations 13, 14, and 15. min w,b,ξ,ξ , ½ ∥w∥ 2 +CΣ i=1 N s (ξ i +ξ i *)  (Equation 13) y i −( w.x i +b )≦ε+Σ i with Σ i ≧0  (Equation 14) − y i +( w.x i +b )≧ε+Σ i *with Σ i *≧0  (Equation 15) A binary classifier ƒ(x) 128 (as in Equation 16, below), which may be used to distinguish youths from adults, is first built by SVMs 126 (as discussed above). In the training steps, the inputs x i refer to the feature vectors 108 extracted using Equation 6 from a given face image and their corresponding labels y i ε{−1,1} (1 for children, −1 for adults). To configure the SVM parameters, a Gaussian kernel K may be used (as in Equation 17), which, in some situations, may generate the best classification rate among possible kernel functions (e.g., linear, polynomial, joint classifier basis (JCB), sigmoid, etc.). f ⁡ ( x ) ⁢ ∑ i = 1 N s ⁢ α i ⁢ y i ⁢ K ⁡ ( s i , x ) + b ( Equation ⁢ ⁢ 16 ) K ⁡ ( x i , x j ) = e - 1 2 ⁢ σ 2 ⁢  x i - x j  2 ( Equation ⁢ ⁢ 17 ) In the testing phase, to estimate the age of an individual's face represented by first image data 154 , first, the CAM algorithm 106 may be used to extract feature vector x 158 from the first image data. As alluded to above, second image data may reside in a pre-assembled database of images of landmarked faces, which may be used to generate aging functions 120 , 124 and an age classifier 128 for use in estimating an age of a subject of the first image data. It is noted that the face age-estimation system that generates the aging functions 120 , 124 and age classifier 128 need not necessarily generate the age-estimation of the first image data. For example, the images in the pre-assembled database may have been “pre-processed” to generate the aging functions and age classifier. This may be so in embodiments in which a particular aging function and/or age classifier has become a standard, such that when each image is added to the database, the aging functions and age classifier are automatically generated/updated as part of the storing process. However, in other examples in which the individual images within a database of training images have not been subjected to processing, an age-estimation system may perform these steps on the second image data, either singly as needed or as part of a larger step of processing some or all of the images in the database to build or update aging functions and/or an age classifier. As with the first image data, such second image data may be preprocessed to account for lighting or other image defects or abnormalities. Once feature vector x 158 has been extracted from the first image data 154 , the individual represented by the first image data may be recognized as a youth or an adult by the SVM-trained youth/adult classifier ƒ(x) 128 . Finally, based on the determination of the young/adult classifier, an appropriate aging function may be used to determine the age of the face: ƒ i (x) 120 may be used if the image is classified as a youth; otherwise ƒ 2 (x) 124 may be used. An estimated age 168 or 172 may be generated using the growth and development 120 or adult aging function 124 , respectively, as appropriate. Estimated ages 168 , 172 may be provided in the form of a single age or age indicator (such as a filename or hash code), which may optionally be provided with a corresponding confidence factor indicating an amount of correlation between the estimated ages and their feature vectors x 158 . Alternatively, estimated ages 168 , 172 may be provided in the form of a set of ages or age indicators, each of which may be provided with corresponding confidence factors. Methods of calculating confidence intervals and the like are well known in the art and, accordingly, will not be described in detail. Estimated ages 168 , 172 may be stored in a face age-estimation system using an appropriate computer storage system (see, e.g., FIG. 4 ) and may be transmitted to a database, through the Internet, to a security system, and/or in any other manner known in the art to be suitable for providing face age-estimation results. FIG. 4 shows a diagrammatic representation of one embodiment of a computer in the exemplary form of a computing system 400 that contains a set of instructions for implementing any one or more of the aspects and/or methodologies of the present disclosure, including implementing methods 100 and 150 and/or any of the other methods of the present disclosure, or portion(s) thereof. Computing system 400 includes a processor 404 and a memory 408 that communicate with each other, and with other components, via a bus 412 . Bus 412 may include any of several types of bus structures including, but not limited to, a memory bus, a memory controller, a peripheral bus, a local bus, and any combinations thereof, using any of a variety of bus architectures. Memory 408 may include various components (e.g., machine readable media) including, but not limited to, a random access memory component (e.g., a static RAM “SRAM”, a dynamic RAM “DRAM”, etc.), a read only component, and any combinations thereof. In one example, a basic input/output system 416 (BIOS), including basic routines that help to transfer information between elements within computing system 400 , such as during start-up, may be stored in memory 408 . Memory 408 may also include (e.g., stored on one or more machine-readable storage media) instructions (e.g., software) 420 embodying any one or more of the aspects and/or methodologies of the present disclosure. In another example, memory 408 may further include any number of program modules including, but not limited to, an operating system, one or more application programs, other program modules, program data, and any combinations thereof. Computing system 400 may also include a storage device 424 . Examples of a storage device (e.g., storage device 424 ) include, but are not limited to, a hard disk drive for reading from and/or writing to a hard disk, a magnetic disk drive for reading from and/or writing to a removable magnetic disk, an optical disk drive for reading from and/or writing to an optical medium (e.g., a CD, a DVD, etc.), a solid-state memory device, and any combinations thereof. Storage device 424 may be connected to bus 412 by an appropriate interface (not shown). Example interfaces include, but are not limited to, SCSI, advanced technology attachment (ATA), serial ATA, universal serial bus (USB), IEEE 1394 (FIREWIRE), and any combinations thereof. In one example, storage device 424 (or one or more components thereof) may be removably interfaced with computing system 400 (e.g., via an external port connector (not shown)). Particularly, storage device 424 and an associated machine-readable storage medium 428 may provide nonvolatile and/or volatile storage of machine-readable instructions, data structures, program modules, and/or other data for computing system 400 . In one example, software 420 may reside, completely or partially, within machine-readable storage medium 428 . In another example, software 420 may reside, completely or partially, within processor 404 . It is noted that the term “machine-readable storage medium” does not include signals present on one or more carrier waves. Computing system 400 may also include an input device 432 . In one example, a user of computing system 400 may enter commands and/or other information into computing system 400 via input device 432 . Examples of an input device 432 include, but are not limited to, an alpha-numeric input device (e.g., a keyboard), a pointing device, a joystick, a gamepad, an audio input device (e.g., a microphone, a voice response system, etc.), a cursor control device (e.g., a mouse), a touchpad, an optical scanner, a video capture device (e.g., a still camera, a video camera), touchscreen, and any combinations thereof. Input device 432 may be interfaced to bus 412 via any of a variety of interfaces (not shown) including, but not limited to, a serial interface, a parallel interface, a game port, a USB interface, a FIREWIRE interface, a direct interface to bus 412 , and any combinations thereof. Input device 432 may include a touch screen interface that may be a part of or separate from display 436 , discussed further below. Input device 432 may be utilized as a user selection device for selecting one or more graphical representations in a graphical interface as described above. A user may also input commands and/or other information to computing system 400 via storage device 424 (e.g., a removable disk drive, a flash drive, etc.) and/or network interface device 440 . A network interface device, such as network interface device 440 may be utilized for connecting computing system 400 to one or more of a variety of networks, such as network 444 , and one or more remote devices 448 connected thereto. Examples of a network interface device include, but are not limited to, a network interface card (e.g., a mobile network interface card, a LAN card), a modem, and any combination thereof. Examples of a network include, but are not limited to, a wide area network (e.g., the Internet, an enterprise network), a local area network (e.g., a network associated with an office, a building, a campus or other relatively small geographic space), a telephone network, a data network associated with a telephone/voice provider (e.g., a mobile communications provider data and/or voice network), a direct connection between two computing devices, and any combinations thereof. A network, such as network 444 , may employ a wired and/or a wireless mode of communication. In general, any network topology may be used. Information (e.g., data, software 420 , etc.) may be communicated to and/or from computing system 400 via network interface device 440 . Computing system 400 may further include a video display adapter 452 for communicating a displayable image to a display device, such as display device 436 . Examples of a display device include, but are not limited to, a liquid crystal display (LCD), a cathode ray tube (CRT), a plasma display, a light emitting diode (LED) display, and any combinations thereof. In addition to a display device, a computing system 400 may include one or more other peripheral output devices including, but not limited to, an audio speaker, a printer, and any combinations thereof. Such peripheral output devices may be connected to bus 412 via a peripheral interface 456 . Examples of a peripheral interface include, but are not limited to, a serial port, a USB connection, a FIREWIRE connection, a parallel connection, and any combinations thereof. The foregoing has been a detailed description of illustrative embodiments of the invention. Various modifications and additions can be made without departing from the spirit and scope of this invention. Features of each of the various embodiments described above may be combined with features of other described embodiments as appropriate in order to provide a multiplicity of feature combinations in associated new embodiments. Furthermore, while the foregoing describes a number of separate embodiments of the system and method of the present invention, what has been described herein is merely illustrative of the application of the principles of the present invention. Additionally, although the methods herein have been illustrated as being performed in a specific order, the ordering is highly variable within ordinary skill to achieve the face age-estimation methods, systems, and software described herein. Accordingly, this description is meant to be taken only by way of example, and not to otherwise limit the scope of this invention.

Age-estimation of a face of an individual is represented in image data. In one embodiment, age-estimation techniques involves combining a Contourlet Appearance Model (CAM) for facial-age feature extraction and Support Vector Regression (SVR) for learning aging rules in order to improve the accuracy of age-estimation over the current techniques. In a particular example, characteristics of input facial images are converted to feature vectors by CAM, then these feature vectors are analyzed by an aging-mechanism-based classifier to estimate whether the images represent faces of younger or older people prior to age-estimation, the aging-mechanism-based classifier being generated in one embodiment by running Support Vector Machines (SVM) on training images. In an exemplary binary youth/adult classifier, faces classified as adults are passed to an adult age-estimation function and the others are passed to a youth age-estimation function.

big_patent

CROSS-REFERENCE TO RELATED APPLICATION [0001] This application claims priority to foreign French patent application No. FR 10 58684, filed on Oct. 22, 2010, the disclosure of which is incorporated by reference in its entirety. FIELD OF THE DISCLOSED SUBJECT MATTER [0002] The present invention relates to a matrix display device for displaying two merged images. It applies more particularly to the simultaneous display of two images whose definitions may differ. BACKGROUND [0003] Some applications involving the display of images involve a need for a merging of images, that is to say a simultaneous display of two images originating from two different sources. The two sources may notably originate from two image sensors of different natures, aiming to restore information of different natures on one and the same scene. For example, it may prove necessary to enable the display of a first image, for example in grey levels and in high definition, produced by a first high definition sensor, simultaneously with a second image, of lesser definition, and typically monochrome or two-color, for example produced by a second sensor. These two images may, for example, correspond respectively to a first image restored by a night vision sensor and a second image restored by an infrared sensor; or even to a first image restored by X-ray radiography, and a second image produced by magnetic resonance imaging. In the abovementioned two cases, the images represent one and the same scene. Also, the first image may represent a scene restored by a high definition sensor, and the second image may represent symbols, text or even menus that have to be displayed simultaneously with the first image. [0004] The present invention relates to the abovementioned applications, as nonlimiting examples, and may also be applied to other examples. More particularly, the present invention relates to the merging of images for a display via a matrix display device. A matrix display device is essentially formed by a matrix of pixels, associated with an addressing system; active matrix and passive matrix systems are known from the prior art. The pixels may, for example, be formed by liquid crystals, commonly designated by the acronym LCD, standing for “Liquid Crystal Display”, or even by light-emitting diodes, or LEDs, or even by organic light-emitting diodes, commonly designated by the acronym OLED. The matrix of pixels is usually associated with a controller, formatting the video signal and generating the control signals intended for the matrix. Hereinafter, it can be assumed, in the interests of simplicity, that a control signal is limited to a light intensity signal, that can be likened to a quantified and standardized value, that may, for example, be a voltage value to be applied to a light-emitting element, or a numeric value, for example coded on 8 bits and thus between 0 and 255, intended for a matrix or for a numeric pixel. It may, for example, be understood that the signals applied are luminance signals, for which the magnitudes vary from a zero value corresponding to a black level, to a maximum value. The formation of an image on a display device, by the application of appropriate signals to the pixels, can be referred to by the term “mapping”. The controller may, for example, be implemented in an integrated electronic circuit of ASIC type, the acronym standing for “Application Specific Integrated Circuit”. The controller may also, for example, be implemented via a programmable microcontroller. The controller may also, for example, be implemented via a programmable component of FPGA type, the acronym standing for “Field-Programmable Gate Array”, of EPLD type, the acronym standing for “Erasable Programmable Logic Device”, or other known types of programmable components. [0005] The devices known from the prior art that make it possible to display merged images as in the examples described above, usually proceed with a display on a polychrome screen, typically of the type commonly designated by the acronym RGB, the acronym referring to the three colors Red, Green, Blue, forming, by combination, all the visible colors, of a merged image generated by a computer, implemented in a dedicated logic circuit, or else via software run on a powerful computer. The merging algorithms may be relatively complex, and the definition of the merged image is significantly degraded, the latter being displayed on a polychrome screen, and being essentially composed of the first monochrome image. In practice, the polychrome display matrices are usually made up of a plurality of groups of pixels or “sub-pixels”, a sub-pixel being dedicated to the display of a basic color, for example by being associated with a color filter, or else by being formed by a luminescent element suitable for producing different colored light signals. Typically, a group may consist of three sub-pixels: each of the pixels being associated with a filter of a basic color, the group then making it possible to display the desired color from a palette of colors, by combination of the sub-pixel control signals. It is, for example, usual practice to employ arrangements of sub-pixels respectively associated with red, green and blue color filters. SUMMARY [0006] One aim of the present invention is to overcome at least the abovementioned drawbacks, by proposing a matrix display device for displaying two merged images, that best preserves the definition of the image that has the higher definition. [0007] One advantage of the invention is that it makes it possible to implement algorithms, the implementation of which is facilitated, and can, for example, be carried out by the controller of the matrix display. [0008] To this end, the subject of the invention is a matrix display device with a definition determined by a plurality of pixels, the matrix display device comprising: at least one controller suitable for producing display light intensity signals for each of the pixels, and a matrix of pixels organized in a mosaic of a plurality of identical arrangements of a predetermined number of pixels, wherein a first plurality of pixels of one of the arrangements are dedicated to display of a first image and receive the light intensity signals associated with the pixels of the first image (I 1 ) that correspond thereto, one or more other pixels of the arrangement are dedicated to the display of a second image (I 2 ) and receiving light intensity signals associated with the pixels of said second image (I 2 ) that correspond thereto, the matrix display device producing the merged display of the first image (I 1 ) and of the second image (I 2 ), the two images (I 1 , I 2 ) being, if necessary, redimensioned by scaling means. [0011] In one embodiment of the invention, each of said arrangements can be formed by a square of four pixels: three pixels of each arrangement being associated with the light intensity signals intended for the corresponding pixels of the first image, and the remaining pixel being associated with the light intensity signal intended for the corresponding pixel of the second image. [0012] In one embodiment of the invention, each of said arrangements can be formed by a square of four pixels: two pixels of each arrangement being associated with the light intensity signals intended for the corresponding pixels of the first image, and the remaining two pixels being associated with the light intensity signals intended for the corresponding pixels of the second image. [0013] In one embodiment of the invention, the pixels dedicated to the display of the first image can emit a first single color, the pixels dedicated to the display of the second image being able to emit a second single color different from the first color. [0014] In one embodiment of the invention, said remaining pixels of the display device can be configured to display two colors which, by combination, make it possible to restore the color associated with the first pixel. [0015] In one embodiment of the invention, the controller can be configured to apply to said three pixels of the arrangements for which said remaining pixels have a quantified light intensity signal value greater than a predetermined threshold value, an attenuation function attenuating the quantified values of the signals to be applied. [0016] In one embodiment of the invention, the attenuation function can attenuate the quantified values of the light intensity signals to be applied respectively to said three pixels Si, according to the following relationship: [0000] Si=b ·exp(− a·S 1 i )· S 1 i [0000] for i=1; 3; 4, a and b being real parameters, S 1 i being the quantified values of the light intensity signals of the corresponding pixels of the first image. [0017] In one embodiment of the invention, the controller can be configured to apply, to said two pixels of the arrangements for which said remaining pixels have a quantified light intensity signal value greater than a predetermined threshold value, an attenuation function attenuating the quantified values of the signals to be applied. [0018] In one embodiment of the invention that is dependent on the preceding embodiment, the attenuation function can attenuate the quantified values of the light intensity signals to be applied respectively to said two pixels, according to the following relationship: [0000] Si=b ·exp(− a·S 1 i )· S 1 i [0000] for i=1; 4, a and b being real parameters. [0019] In one embodiment of the invention, said remaining pixels of the display device are configured to display two colors which, by combination, make it possible to restore the color associated with the first image. [0020] In one embodiment of the invention, the controller can be configured to apply, to said remaining two pixels of each of the arrangements of the display device for which the pixels of the arrangements of said second image that correspond thereto have a quantified light intensity signal value less than a determined threshold, values derived from a combination of the quantified values of the light intensity signals of the first image, according to the following relationships: [0000] S 2=a*( S 12+ S 13)/2, [0000] S 3=b*( S 12+ S 13)/2; [0000] a and b being real parameters, the sum of which equals 2. [0021] In one embodiment of the invention, the matrix display device can include a first controller interfacing with said first number of pixels of each arrangement and corresponding to the first image, and a second controller interfacing with the other pixels of each arrangement and corresponding to said second image. [0022] According to various embodiments of the invention, the matrix display device can be configured to display a first image, essentially monochrome, produced by a night vision sensor or by an infrared sensor or by an X-ray imaging sensor, merged with the display of a second image, essentially monochrome, produced by an infrared sensor, by an echography sensor, or a monochrome or two-color symbology image. BRIEF DESCRIPTION OF THE DRAWINGS [0023] Other features and advantages of the invention will become apparent from reading the description, given by way of example, in light of the appended drawings which represent: [0024] FIG. 1 , a diagram giving a synoptic presentation of the general principle of a matrix display device, in an exemplary embodiment of the invention; [0025] FIG. 2 , a diagram giving a synoptic presentation of the display produced by an arrangement of pixels, in a first exemplary embodiment of the invention; [0026] FIG. 3 , a diagram giving a synoptic presentation of the display produced on an arrangement of pixels, in a second exemplary embodiment of the invention; [0027] FIG. 4 , a diagram presenting an exemplary embodiment of a matrix display device according to one embodiment of the invention. DETAILED DESCRIPTION [0028] FIG. 1 is a diagram presenting a synoptic illustration of the general principle of a matrix display device according to an exemplary embodiment of the present invention. [0029] A first image I 1 is partially illustrated in FIG. 1 , the first image I 1 having first, if necessary, been redimensioned so as to offer a definition identical to the definition of the matrix of pixels of a display device 100 . In the example illustrated in FIG. 1 , the matrix of pixels of the display device 100 is rectangular, with n columns and p rows of pixels. The present invention can also be applied to matrices of different forms. The display device 100 may, for example, be a display of OLED, or LED, or LCD type, or of any other known type, associated with a controller which is not represented in FIG. 1 . [0030] Similarly, a second image I 2 is partially illustrated in FIG. 1 , this also having, if necessary, been redimensioned so as to offer a definition identical to that of the matrix of pixels of the display device 100 , or else to a definition corresponding to a subdefinition of that of the matrix of pixels of the display device 100 , for example, a quarter thereof. [0031] The redimensioning, sometimes referred to by the term “upscaling” if the native definition of the image is lower than the definition of the display, or else by the term “downscaling” in the opposite case, can, for example, be implemented by a microcontroller which is not represented in FIG. 1 , according to methods which are intrinsically known from the prior art and not explained in the present description. [0032] According to a specific feature of the present invention, a mosaic may be considered, this mosaic covering all the pixels of the two images I 1 , I 2 and the matrix of the display device 100 , and being formed by a plurality of identical arrangements of pixels. In the example illustrated in FIG. 1 and the subsequent figures, a square arrangement of four pixels P 1 , P 2 , P 3 , P 4 is considered. The present invention can, obviously, be applied with arrangements of a plurality of pixels, the number of which may differ from four, the form of the arrangements not necessarily being square or rectangular, provided that the arrangements as a whole can cover all the pixels considered. [0033] The merged image resulting from the two images I 1 , I 2 can be formed via appropriate light intensity signals. Thus, the light intensity signals that make it possible to form the pixels P 1 , P 2 , P 3 , P 4 of an arrangement of pixels of the merged image can be respectively denoted S 1 , S 2 , S 3 , S 4 . The light intensity signals that make it possible to form the corresponding four pixels of the arrangement of the first image I 1 alone can be denoted S 11 , S 12 , S 13 , S 14 , and, similarly, the light intensity signals that make it possible to form the four pixels of the arrangement of the second image I 2 that correspond thereto can be denoted S 21 , S 22 , S 23 , S 24 . [0034] The present invention proposes that each pixel P 1 , P 2 , P 3 , P 4 of an arrangement of pixels of the merged image be formed either via a light intensity signal S 11 , S 12 , S 13 , S 14 that makes it possible to form the first image I 1 , or via a light intensity signal S 21 , S 22 , S 23 , S 24 that makes it possible to form the second image I 2 , or via a light intensity signal resulting from a combination of the abovementioned signals S 11 , S 12 , S 13 , S 14 and S 21 , S 22 , S 23 , S 24 that makes it possible to respectively form the first image I 1 and the second image I 2 . Thus, a first number of pixels of an arrangement may receive light intensity signals associated with the pixels of the first image I 1 that correspond thereto, and the other pixels of the arrangement may receive the light intensity signals associated with the pixels of the second image I 2 that correspond thereto, or light intensity signals determined by a combination of the light intensity signals associated with the pixels of the two images I 1 , I 2 . Different examples of arrangements of pixels are described hereinbelow, notably with reference to FIGS. 2 and 3 ; it should be noted that these examples are in no way limiting on the present invention, and that other arrangements of pixels can be envisaged. [0035] FIG. 2 is a diagram presenting a synoptic illustration of the display of two merged images produced on an exemplary arrangement of pixels, according to a first possible embodiment of the invention. [0036] FIG. 2 presents an arrangement of four pixels P 1 , P 2 , P 3 , P 4 . For each arrangement of pixels, it is, for example, possible to reserve for a first pixel, for example for the first pixel P 1 of the matrix of the display device, the light intensity signal S 11 that makes it possible to display the first pixel P 1 of the first image. It is possible to also reserve for two other pixels, for example for the third and fourth pixels P 3 , P 4 of the matrix of the display device, the light intensity signals S 13 and S 14 that respectively make it possible to display the third and fourth pixels of the first image. Finally, it is possible to reserve for the last pixel of the arrangement, that is to say, for example, for the second pixel P 2 of the matrix of the display device, the light intensity signal S 22 that makes it possible to display the second pixel P 2 of the second image. Such an exemplary arrangement is particularly suited to the cases where the second image is monochrome. In this exemplary embodiment, the second pixel P 2 , for each arrangement of the matrix of the display device, can be associated with a colored filter. [0037] Practically, the display of the duly merged image can, for example, be implemented via the following operations, performed by means of the controller of the display device: a first operation of mapping the first image to the display device, the controller then applying the light intensity signals S 11 , S 13 and S 14 respectively to the first, third and fourth pixels P 1 , P 3 , P 4 of all the arrangements of pixels forming the display device; a second operation of mapping the second image to the display device, the controller then applying the light intensity signal S 22 to the second pixels P 2 of all the arrangements of pixels forming the display device. It can be seen here that the mapping of the second image I 2 to the display device is produced on a definition corresponding to the number of pixels intended for the display of the second image I 2 ; that is to say, in the case of the example described here, the pixels P 2 being assigned to the display of the image I 2 , on a quarter of the definition of the matrix of the display device. [0040] FIG. 3 is a diagram presenting a synoptic illustration of the display of two merged images produced on an exemplary arrangement of pixels, according to a second possible embodiment of the invention. [0041] FIG. 3 presents an arrangement of four pixels P 1 , P 2 , P 3 , P 4 . For each arrangement of pixels, it is, for example, possible to reserve for a first pixel, for example for the first pixel P 1 of the matrix of the display device, the light intensity signal S 11 that makes it possible to display the first pixel P 1 of the first image. It is possible to also reserve for a second pixel, for example the fourth pixel P 4 of the matrix of the display device, the light intensity signal S 14 that makes it possible to display the fourth pixel of the first image. Finally, it is possible to reserve for the other two pixels, that is to say, for example, the second and third pixels P 2 , P 3 of the matrix of the display device, the signals intended for the pixels of the arrangement concerned of the second image that correspond thereto, that is, respectively, the light intensity signals S 22 and S 23 . Such an exemplary arrangement is particularly suited to the cases where the second image is two-color. For example, colored filters can be assigned to the second and third pixels P 2 , P 3 of all the arrangements of pixels of the matrix of the display device. [0042] Advantageously, the colored filters associated with the second and third pixels P 2 , P 3 may be of colors which, in combination, make it possible to visually restore the color associated with the first pixel P 1 . For example, the colored filters associated with the second and third pixels P 2 , P 3 may be of two complementary colors, so that, by addition, they can restore the white color. The colored filters associated with the second pixels P 2 of the arrangements forming the matrix of the display device may, for example, be of red color, and the filters associated with the third pixels P 3 may, for example, be of cyan color. [0043] Practically, the display of the duly merged image can, for example, be implemented via the following operations, performed by means of the controller of the display device: a first operation of mapping the first image to the display device, the controller then applying the light intensity signals S 11 and S 14 respectively to the first and fourth pixels P 1 and P 4 of all the arrangements of pixels forming the display device; a second operation of mapping the second image to the display device, the controller then applying the light intensity signals S 22 and S 23 respectively to the second and third pixels P 2 and P 3 of all the arrangements of pixels forming the display device. Since the second image consists of two colors, the mapping may consist in mapping the first color to the submatrix consisting of the second pixels P 2 , that is to say on a resolution corresponding to a quarter of the resolution of the matrix of the display device, and in the mapping of the second color to the submatrix consisting of the third pixels P 3 , that is to say on a resolution that also corresponds to a quarter of the resolution of the matrix of the display device. [0046] Advantageously, for the pixels of the second image for which the light intensity signals S 22 and S 23 respectively for the second and third pixels P 2 and P 3 are below a determined threshold value, that is to say where the second image is not visible, or is only barely visible, the second operation may be replaced with an alternative operation. This alternative operation may consist in applying to the second and third pixels of the matrix of the display device, for example for the pixels of the matrix of the display device that correspond to pixels of the second image intended to be displayed with a signal for which the light intensity is situated below the threshold, light intensity signals for example determined by the controller, corresponding to a combination of the values of the light intensity signals S 12 and S 13 of the first image. For example, it is possible to apply to the pixels P 2 and P 3 respectively the signals S 2 and S 3 , the values of which are defined by the following relationships: [0000] S 2= a *( S 12+ S 13)/2, [0000] S 3= b *( S 12+ S 13)/2; [0000] a and b being real parameters, the sum of which equals 2. [0047] Advantageously, the parameters a and b can be chosen so as to generate, by combining the light of the pixels P 2 and P 3 , the same color as those of the pixels P 1 and P 4 . It is obviously possible to envisage applying more complex formulae for the combination of the two signals S 2 and S 3 , these being able to be linear or nonlinear relationships. [0048] This may prove particularly advantageous when the useful part of the second image covers only a part of the surface thereof, notably in the case where the second image represents a symbol or textural information. [0049] Also advantageously, means for reinforcing the contrast of the merged image may be implemented, for example by means of the controller of the display device. [0050] In fact, the color or colors of the second image may appear saturated only on the parts of the merged image for which the background of the first image is relatively dark. On the lighter parts of the first image, the color of the pixels of the matrix of the display device conveying information relating to the second image, that is to say the second pixel P 2 in the case of the first example mentioned above and illustrated in FIG. 2 , or the second and third pixels P 2 and P 3 in the case of this second example mentioned above and illustrated FIG. 3 , may appear with little saturation, that is to say visually appear like a pastel color. The means for reinforcing the contrast of the merged image may make it possible to obtain a good saturation of the colors of the second image while keeping a maximum display area for the first image. [0051] Thus, the contrast reinforcement means may be configured so as to correct the display of the first image as follows, given as an example which is not limiting on the present invention: in the case of the first example mentioned above, for the second pixels P 2 for which the light intensity signal is different from the light intensity signal corresponding to a black level, or else for which the quantified value is greater than a predetermined threshold value, it is possible to determine the quantified values of the light intensity signals S 1 , S 3 and S 4 to be applied respectively to the first, third and fourth pixels of the arrangements, for example according to the following relationship: [0000] Si=b ·exp(− a·S 1 i )· S 1 i , for i= 1 ; 3 ; 4 ;   (1) [0000] in the case of the second example mentioned above, for the second and third pixels P 2 and P 3 for which the light intensity signal is different from the light intensity signal corresponding to a black level, or else for which the quantified value is greater than a predetermined threshold value, it is possible to determine the quantified values of the light intensity signals S 1 and S 4 to be applied respectively to the first and fourth pixels of the arrangements, for example according to the following relationship: [0000] Si=b ·exp(− a·S 1 i )· S 1 i , for i= 1; 4,   (2) [0000] a and b in the relationships (1) and (2) above are parameters that can be defined and set by means of the controller according to the targeted applications, or even parameters than can be modified by a user, for example via external control means making it possible to modify the configuration of the controller. [0052] It should be noted that other functions can be applied for the determination of the values of the signals to be applied, the important thing to remember here being that the function applied should allow for an attenuation of the light levels of the first image, without in any way attenuating too much the darker levels. [0053] In practice, a display device according to one of the embodiments described previously may, for example, be based on a matrix display device associated with a controller, the controller being able, for example, to be integrated in the matrix, or else external thereto. [0054] It is also possible, in an advantageous embodiment, for the display device to be based on a dedicated hardware architecture, notably offering an advantage in terms of lower consumption in operation. An exemplary hardware architecture may be based on a matrix of pixels associated with two controllers, as described hereinbelow with reference to FIG. 4 , illustrating an exemplary embodiment of a matrix display device according to one embodiment of the invention. [0055] A matrix display device 40 may, for example, comprise a mosaic of a plurality of arrangements of four pixels P 1 , P 2 , P 3 , P 4 . The matrix display device 40 is thus particularly suited to the first embodiment described previously with reference to FIG. 2 . [0056] A first controller 41 , for example integrated in the structure containing the matrix, may be interfaced, via physical connection lines, with three pixels of each arrangement: the pixels P 1 , P 2 , P 3 in the example illustrated in FIG. 4 . [0057] A second controller 42 , for example also integrated in the structure containing the matrix, may be interfaced, via physical connection lines, with the remaining pixel of each arrangement: the pixel P 4 in the example illustrated by the in FIG. 4 . [0058] In this way, a video stream intended for a display on the matrix display device 40 can be displaced in interleaved manner, in the form of a first video stream generated by the first controller 41 , and of a second video stream generated by the second controller 42 . In such a configuration, each pixel is formed by one or more pixels (three in the example illustrated in FIG. 4 ) driven by the first controller 41 , and one or more pixels (one in the example of FIG. 4 ) being driven by the second controller 42 . Generally, the pixels dedicated respectively to the display of the first and the second image may be designed so as to emit different colors, by being, for example, associated with filters of dedicated colors. For example, the pixels dedicated to the display of the first image may be designed so as to emit a single first color, the pixels dedicated to the display of the second image being designed so as to emit a single second color, different from the first color. [0059] In a typical exemplary application, the displayed image may have a definition of 800×500 pixels, the first image having, for example, an identical definition and giving a monochrome illustration of the visible field, and the second image having, for example, a definition four times lower, that is to say 400×250 pixels 2 , and illustrating, for example, the infrared field. In this typical configuration and according to the example illustrated in FIG. 4 , the pixels P 4 of the arrangements forming the matrix are, for example, associated with a filter of red color. [0060] Another advantage obtained by such a device is that the two video streams generated by each of the two controllers 41 , 42 can have different definitions. Similarly, the two video streams can have different refresh frequencies. This way, the overall consumption of the matrix display device 40 is minimized. [0061] Practical exemplary embodiments of the present invention are described hereinbelow. [0062] According to a first example, the image displayed by the matrix display device may combine a first image originating from a night vision sensor with a second graphical image, for example generated by a microcontroller or a microcomputer. The first image may, for example, be a monochrome image, with a definition of 2000×2000 pixels, the color displayed being, for example, white or a first color C 1 . The second image may consist of graphical information (for example, icons, cursors, menus, etc.) or textual information (position, time and other such information), the color displayed being, for example, red, or else a second color C 2 different from the first color C 1 . [0063] In this first example, the matrix display device may comprise a video controller, for example of FPGA type, a video interface with the night vision sensor, a video interface with the microcontroller or microcomputer for the display of the second image, an output interface with the matrix of pixels, the latter forming a dedicated display panel comprising arrangements of four pixels in squares. The definition of the matrix of pixels can then be 2000×2000 pixels, the arrangements of four pixels P 1 to P 4 consisting of three pixels P 1 , P 3 and P 4 emitting in the white color or in the first color C 1 , the remaining pixel P 2 emitting in the red color or in the second color C 2 . [0064] The matrix of pixels may be formed by a microdisplay of OLED type with active matrix with white emitters (or emitters in the first color C 1 ), a red colored filter (or a filter of the second color C 2 ) being associated with the pixels intended for the display of the second image, or else these pixels being associated with red emitters or emitters in the second color C 2 . [0065] According to this first example, the combined display of the two images may then consist of a display of the first image on the matrix of 2000×2000 pixels with one pixel out of every four (the pixels P 2 ) omitted. With S 11 , S 12 , S 13 and S 14 designating the intensity signals corresponding to the first image to be applied respectively to the pixels P 1 , P 2 , P 3 , P 4 , S 11 is applied to the pixel P 1 , S 13 to the pixel P 3 and S 14 to the pixel P 4 . The second image can then be displayed on the remaining pixels P 2 , by applying the signal S 22 (intensity signal corresponding to the second image). [0066] Depending on the intensity of the first image, the second image may appear more or less saturated. In this first example, the red of the second image may appear pink on a light background (that is to say, the first image). To compensate this phenomenon, a local correction of the intensity of the first image can be performed, around display areas of the second image, that is to say in places where the intensity of the second image is different from zero, or else is above a determined threshold. As is described previously, in order not to excessively degrade the color saturation, the signals S 11 , S 13 and S 14 may be attenuated so that the attenuation is maximum if the intensity is strong (white background), and negligible when the intensity is weak (dark background), for example: [0067] if S 22 > determined threshold value, then: [0000] S 1 i (corr)=exp(− a*S 1 i )* S 1 i, i= 1, 3, 4, [0000] a being a parameter to be determined according to the application. For example, if the image 2 contains symbols, a value of a of between 0.002 and 0.006 gives satisfactory results. Thus, the color of the first image remains fairly saturated, whereas the second image remains transparent; in other words, it is still possible to clearly distinguish the details of the first image behind the symbols of the second image. [0068] According to a second example, the image displayed by the matrix display device may combine a first image originating from a night vision sensor with a second image derived from an infrared sensor targeting the same scene. The first image may, for example, be a monochrome image, with a definition of 2000×2000 pixels, the color displayed being, for example, white or a first color C 1 . The second image may also be monochrome, with a lower resolution: for example 480×480 pixels, the color displayed being, for example, red, or else a second color C 2 different from the first color C 1 . [0069] In this second example, the matrix display device may comprise a video controller, for example of FPGA type, a first video interface with the night vision sensor, a second video interface with the infrared sensor, an image processing unit for performing the mapping of the second image, that is to say, the adaptation of the definition thereof, dictated by the infrared sensor, to the resolution of the matrix of pixels reserved for the display of the second image (for example 1000×1000 pixels if one pixel in every four is used for this purpose, as is explained hereinbelow), an output interface with the matrix of pixels, the latter forming a dedicated display panel comprising arrangements of four pixels in squares. The definition of the matrix of pixels may then, like the first example described previously, be 2000×2000 pixels, the arrangements of four pixels P 1 to P 4 consisting of three pixels P 1 , P 3 and P 4 emitting in the white color or in the first color C 1 , the remaining pixel P 2 emitting in the red color or in the second color C 2 . [0070] The matrix of pixels may also be formed by a microdisplay of OLED type with active matrix with white emitters (or emitters in the first color C 1 ), a red colored filter (or a filter of the second color C 2 ) being associated with the pixels intended for the display of the second image, or else these pixels being associated with red emitters, or emitters in the second color C 2 . [0071] The combined display of the two images can be produced in a way similar to the first example described previously. In order to obtain a good visibility on both images, it is important in this second example to apply the intensity correction to the first image from a certain threshold of intensity of the second image only, and to apply the parameter a appropriately. [0072] It should be noted that all the embodiments described hereinabove apply to the combined display of two images. However, a matrix display device according to the present invention may also display a plurality of combined images, with arrangements of pixels in which pixels are dedicated to different images out of the plurality of images. [0073] Thus, according to a third example, in a manner similar to the second example described previously, the image displayed by the matrix display device may combine a first image originating from a night vision sensor with a second image derived from an infrared sensor targeting the same scene, but also with a third image, for example generated by a microcontroller or a microcomputer, like the second image in the first example described previously. The first image may, for example, be a monochrome image, with a definition of 2000×2000 pixels, the color displayed being, for example, white or a first color C 1 . The second image may also be monochrome, with lower resolution: for example 480×480 pixels, the color displayed being, for example, red, or else a second color C 2 different from the first color C 1 . The third image may consist of graphical information (for example, icons, cursors, menus, etc.) or textual information (position, time or other such information), the color displayed being, for example, cyan, or else a third color C 3 different from the first color C 1 and from the second color C 2 . [0074] In the third example, the matrix display device may comprise a video controller, for example of FPGA type, a first video interface with the night vision sensor, a second video interface with the infrared sensor, a third video interface with the microcontroller or microcomputer for the display of the second image, an image processing unit for producing the mapping of the second image like in the second example described previously, an output interface with the matrix of pixels, the latter forming a dedicated display panel comprising arrangements of four pixels in squares. The definition of the matrix of pixels may then be 2000×2000 pixels, the arrangements of four pixels P 1 to P 4 consisting of two pixels P 1 and P 4 emitting in the white color or in the first color C 1 , the pixel P 2 being dedicated to the display of the second image and emitting in the red color or in the second color C 2 , and the pixel P 3 emitting in the cyan color or in the third color C 3 , and being dedicated to the display of the third image. [0075] The matrix of pixels may be formed by a microdisplay of OLED type with active matrix with white emitters (or emitters in the first color C 1 ), a red colored filter (or a filter of the second color C 2 ) being associated with the pixels intended for the display of the second image, or else these pixels being associated with red emitters or emitters in the second color C 2 , a cyan colored filter (or filter of the third color C 3 ) being associated with the pixels intended for the display of the third image, or else these pixels being associated with emitters in cyan or in the third color C 3 . [0076] According to this third example, the combined display of the three images may then consist of a display of the first image on the matrix of 2000×2000 pixels with two pixels in every four (the pixels P 2 and P 3 ) omitted. With S 11 , S 12 , S 13 and S 14 designating the intensity signals corresponding to the first image to be applied respectively to the pixels P 1 , P 2 , P 3 , P 4 , S 11 is applied to the pixel P 1 and S 14 to the pixel P 4 . The second image may then be displayed on the pixels P 2 , by applying the signal S 22 (intensity signal corresponding to the second image), and the third image may be displayed on the pixels P 3 , by applying the signal S 33 . [0077] Depending on the intensity of the first image, the second and third images may appear more or less saturated. Thus, the red of the second image may appear pink on a light background (that is to say, the first image). To compensate this phenomenon, a local correction of the intensity of the first image can be performed, around areas of display of the second and of the third images, that is to say in places where the intensity of the second or the third image is different from zero, or else is above a determined threshold. The signals S 11 and S 14 can thus be attenuated such that the attenuation is maximum if the intensity is strong (white background), and negligible when the intensity is weak (dark background), for example: if S 22 > first determined threshold value OR S 33 > second determined threshold value, then: [0000] S 1 i (corr)=exp(− a*S 1 i )* S 1 i, i= 1, 4, [0000] a being a parameter to be determined according to the application. For example, if the image 2 contains symbols, a value of a between 0.002 and 0.004 gives satisfactory results. Thus, the color of the first image remains fairly saturated, whereas the second and third images remain transparent. [0079] In order to further enhance the efficiency of the first image, it is possible, as described previously, to use the pixels P 2 and P 3 for the display of the first image in places thereof where no overlay of the second or third image is present, or else in places of the first image where the intensity of the overlays remains below a determined threshold. By having chosen complementary colors for the pixels P 2 and P 3 of the arrangements, that is to say that their superimposition generates the white color, a combination of P 2 and P 3 may replace a white pixel. It is then possible to display on the pixels P 2 and P 3 the following signals: [0080] if S 22 < third threshold value AND S 33 < fourth threshold value, then: [0000] S 2=( S 12+ S 13)/2 [0000] S 3=( S 12+ S 13)/2 [0000] In this way, it is possible to profit from a maximum of resolution for the first image.

A matrix display device with a definition determined by a plurality of pixels, the matrix display device including at least one controller suitable for producing display light intensity signals for each of the pixels; and a matrix of pixels organized in a mosaic of a plurality of identical arrangements of a determined number of pixels, wherein a first number of pixels of an arrangement are dedicated to display of a first image and receives the light intensity signals associated with the pixels of the first image that correspond thereto, one or more other pixels of the arrangement are dedicated to display of a second image and receiving light intensity signals associated with the pixels of said second image that correspond thereto, the matrix display device producing the merged display of the first image and of the second image, the two images being, if necessary, redimensioned by scaling means.

big_patent

TECHNICAL FIELD [0001] The invention relates to a mobile identification transmitter for the purpose of activating a security system of a motor vehicle, particularly an access and/or ignition control system, having a housing in which electronics and a communication means are arranged, wherein the communication means can be brought into communication with a communication means of the security system located on board the motor vehicle. BRIEF DESCRIPTION OF RELATED ART [0002] DE 10 2010 061 331.2 discloses a keyless security system of a motor vehicle. In this case, the authorized user can actively operate the mobile identification transmitter in order to transmit a signal to the base station, for example a receiver unit included in the motor vehicle, to unlock/lock the motor vehicle. [0003] The identification data contained in the data unit can also be regenerated in known access control procedures. In addition, electronic locking systems for motor vehicles are currently expanding in the market, and are equipped with both the functionality described above, requiring manual operation, and also a functionality which does not require manual operation, the so-called “Keyless-Go” or “Keyless Entry” functionality. In contrast to the conventional remote control, the keyless entry functionality does not require operation of the identification transmitter to unlock/lock a motor vehicle door or the motor vehicle trunk, or other components of the motor vehicle. Rather, upon operation of the door handle on the automobile door, communication is initiated between the motor vehicle and the identification transmitter, and the electrical door opening, trunk opening, etc. of the motor vehicle is activated upon a positive authentication. This means that the user carrying a valid identification transmitter can unlock and/or lock his motor vehicle without needing to actively operate the identification transmitter. For example, an access control method is known wherein a transmission pulse is transmitted via an inductive antenna to the identification transmitter upon the operation of the door handle. The identification transmitter is then awakened as a result and transmits a radio signal to the transmitter/receiver unit on board the motor vehicle, which then relays this signal from the control unit for the access authorization. If the correct code is recognized at this point, then the electrical door unlock is activated. The same process can play out in a door locking procedure as a result of the door handle being touched. BRIEF SUMMARY [0004] The problem addressed by the present invention is that of creating a mobile identification transmitter for a keyless activation of a security system of a motor vehicle which possesses an enlarged functionality and has a simple design, wherein at the same time the user is provided with a comfortable mobile identification transmitter. [0005] According to the invention, for this purpose a payment element is removably fastened in a receptacle of the housing, a closure is separately arranged on the housing, the identification transmitter can be set in a normal state and in a secure state, in the normal and in the secure state it is possible to execute a communication with the security system, in the secure state the payment element of the receptacle is removed, and the closure protects and seals the receptacle. [0006] The payment element can be removed from the housing of the identification transmitter by the user if necessary. This is the case, for example, if the motor vehicle having the identification transmitter is brought to a repair shop, or a third person receives the mobile identification transmitter in order to, for example, park the motor vehicle, etc. By means of the payment element which is removably fastened in the receptacle of the housing, the user can carry out various payment actions, for example at a gas station, in a shopping center, etc. During the payment process, the payment element preferably remains inside the housing. In order to rule out the risk of an unauthorized person carrying out a payment function using the mobile identification transmitter, the authorized user can remove the payment element from the housing at any time, wherein all additional functions of the mobile identification transmitter, particularly the keyless activation of the security system of the motor vehicle, remain preserved. This means that both in the identification transmitter normal state and secure state, it is possible to carry out communication with the security system. However, if the mobile identification transmitter is in the secure state, a payment action is blocked because the payment element is no longer located in the receptacle of the housing of the identification transmitter. In order to ensure the functionality of the identification transmitter according to the invention, it is necessary that, particularly in the secure state, the receptacle in which the payment element is normally located is effectively sealed. Particularly in the event that moisture, dirt particles, etc. penetrate the receptacle from the outside, for the normal state of the identification transmitter it has been shown that the electrical connection between the payment element and the electronics integrated inside the housing can be disadvantageously disturbed, whereby payment actions are disadvantageously no longer possible via the payment element. The closure according to the invention effectively prevents any disruptions to the connection between the payment element and the electronics of the identification transmitter arranged therein, and/or prevents the occurrence of any communication disruptions between the payment element and the electronic payment system. In addition, the sealing closure prevents moisture, dirt particles, etc. from being able to penetrate into the interior of the housing when the identification transmitter is in the secure state, whereby the electronics responsible for communication with the security system on board the vehicle would also be damaged. [0007] In a further measure which improves the invention, in the normal state the payment element can be brought into data communication with a payment system, and the payment element particularly has a credit card function and/or a debit card function. [0008] The payment element can have a microprocessor, wherein the payment element can communicate with the payment system, and particularly can execute remote financial transactions such as loading a certain amount of money onto the payment element or debiting a defined amount from the payment element. For example, the payment element can be provided only for small sums, particularly as a payment means for paying small daily costs, whereby in this manner an insert for the use of small amounts of electronic cash is offered. In addition, the payment element can be equipped in such a manner that amounts can be transferred in communication with the payment system without any limit. [0009] The payment element is advantageously designed having a storage device, wherein the payment element can be designed in an additional embodiment of the invention as having an integrated circuit which can have one or multiple microprocessors. In this case, the microprocessors and the storage device play an important role in one possible embodiment of the invention with regard to security, because the storage device can contain codes, for example, for the authorization, for control, for new balances, etc. In one possible embodiment of the invention, the microprocessor can be disposed to carry out complex calculation algorithms or to evaluate a secret value from the identification data input into the microprocessor. [0010] After the payment element is brought into data communication with the electronic payment system, in one embodiment of the invention the payment element can remain non-functioning if the calculated secret code is not equal to a secret code already located in the card. [0011] The receptacle advantageously has contact elements, wherein the payment element in the normal state contacts and is connected to said contact elements, wherein in the secure state the closure protects the contact elements from the external environment. In the normal state of the mobile identification transmitter, the payment element, particularly having its own on-board contact elements, directly abuts the contact elements on the receptacle. In addition, in the configuration the payment element as such likewise has a reliable sealing function, such that in the normal state of the identification transmitter, likewise no moisture, dirt particles, etc. can penetrate into the receptacle and/or into the housing. The contact elements of the receptacle are sealed and protected in the secure state of the identification transmitter via the closure, and in the normal state of the identification transmitter via the payment element. [0012] Similarly, a carrier can be included, wherein the payment element is integrated into said carrier, and the carrier is removably fastened in the receptacle. In the normal state of the identification transmitter, the carrier is inserted in the receptacle of the housing, wherein for the user the carrier can constitute, at least in a section thereof, a component of the housing. The carrier is advantageously matched to the corresponding geometry of the receptacle of the housing, such that the carrier is reliably held in the receptacle of the housing. The carrier can, for example, be fastened on the housing, particularly on the receptacle of the housing, in a positive-fitting and/or force-fitting manner. [0013] The closure can advantageously be movably mounted on the housing, and can move between an active position and a passive position, wherein the identification transmitter is in the active position when in the secure state. In the passive position of the closure, the payment element is located in the receptacle of the housing such that payment actions can be initiated by the user. [0014] In addition, a configuration can be contemplated wherein via a corresponding, intentional activation of the identification transmitter, particularly of an activation element, the payment element and/or the carrier can be removed from the receptacle of the housing by the user. This means that in the normal state of the identification transmitter, the payment element is located in the receptacle of the housing and is secured in that location in such a manner that any removal thereof from the receptacle is blocked. This can be realized, for example, via locking elements which act directly on the payment element and/or on the carrier. Only once the user consciously initiates an activation of the identification transmitter will the blocking of the payment element and/or of the carrier in the receptacle be lifted, such that the user can then remove the payment element from the receptacle. [0015] A configuration can likewise be contemplated wherein an energy storage device is included which supplies the electronics and/or the payment element with current. As such, it is possible to include only one energy storage device in the identification transmitter which supplies the electronics inside the housing with current, and also makes a payment action via the payment element possible. Likewise, a second energy storage device can be contained in the mobile identification transmitter as a redundancy. In addition, the one energy storage device can likewise recharge the additional energy storage device in the event that a discharge of energy and/or energy consumption has occurred. The first and/or the second energy storage device can be designed as a battery, an accumulator, a magnetic energy storage device, or as a capacitor. [0016] In addition, the closure can be designed as a dummy plug which is particularly fastened to a cable of the housing. In this case, the cable can be flexible and/or elastic, wherein the cable functions as a security element such that the closure does not release from the identification transmitter and therefore becomes lost. The advantage of designing the closure as a dummy plug is that a reliable hold is ensured in the receptacle via the plug function, wherein the receptacle has a corresponding fastening means with which the dummy plug can engage. [0017] A configuration can likewise be contemplated wherein the carrier and/or the payment element has its own communication means for communication with the payment system. This means that an independent, second communication means is used on board the identification transmitter for the keyless activation of the security system of the motor vehicle, and the same is located on the carrier and/or on the payment element. [0018] Similarly, the communication means of the identification transmitter can simultaneously serve the purpose of communication with the payment system. [0019] It is particularly advantageous that a cashless payment transaction can take place at a point of sale (POS) by means of the removable payment element, wherein it is possible to execute an electronic debit, wherein the same can take place as an online process or as an offline process, for example. In the case of the online process, the electronic payment system is connected to a card operator, for example Maestro, VISA, etc., with or without the support of a computer. In this case, the payment element is checked for misuse by utilizing numbers and a PIN, and then the debiting of the customer's account can be performed by a corresponding transaction between the card operator and the customer's bank. Likewise, it can be contemplated that the electronic debit process is carried out in an offline process, wherein only the account data is used during the payment action. For the purpose of obtaining permission for the charge, particularly for the debiting procedure, the seller, agent, etc. obtains permission for the charge by receiving a signature from the customer on the receipt, wherein said customer carries the identification transmitter according to the invention with him or her. [0020] In order to increase the security of the communication between the payment element and the payment system, the communication means of the payment element advantageously has a range of less than 20 cm, particularly less than 10 cm. The payment element and the electric payment system advantageously communicate with each other cryptographically. Likewise, the communication means of the payment element can work in a frequency range of approx. 13.56 MHz, whereby it is particularly possible to achieve data transmission rates of more than 400 kBits per second. The communication between the payment element and the payment system can be carried out via Bluetooth or via a near field communication technique. [0021] Additional advantages, features, and details of the invention are found in the description below, wherein multiple embodiments of the invention are described in detail with reference to the illustrations. The features indicated in the claims and in the description can be essential to the invention either alone or in any combination thereof. BRIEF DESCRIPTION OF THE DRAWINGS [0022] FIG. 1 shows a purely schematic illustration of a mobile identification transmitter having a payment element which is located in a receptacle of the housing of the identification transmitter, [0023] FIG. 2 shows the identification transmitter in FIG. 1 , wherein the payment element is removed from the receptacle of the housing, [0024] FIG. 3 shows a further variant of a mobile identification transmitter according to FIG. 1 , [0025] FIG. 4 shows an enlarged view of the receptacle of the housing in FIG. 1 in an additional embodiment variant, and [0026] FIG. 5 shows a further embodiment of a receptacle of the housing in FIG. 1 . DETAILED DESCRIPTION [0027] In FIG. 1 and FIG. 2 , a mobile identification transmitter 1 is illustrated which serves to activate a security system of a motor vehicle 2 . In addition, this embodiment discloses a system wherein a payment element 40 which is arranged inside the mobile identification transmitter 1 can be brought into data communication with an electronic payment system 6 . In addition, the mobile identification transmitter 1 has electronics 30 which can contain stored identification data. In addition, the motor vehicle 2 has communication means 3 which can be designed as a transmitter and/or receiver unit. In addition, the mobile identification transmitter 1 has a communication means 31 which can communicate with the communication means 3 on board the motor vehicle. The security system of the motor vehicle 2 is only activated, for the purpose of carrying out an unlocking or locking process of the motor vehicle door, once a positive authentication has been determined following the communication between the communication means 3 , 31 . This means that the user carrying a valid identification transmitter 1 can open his motor vehicle 2 , for example. [0028] The housing 10 of the mobile identification transmitter 1 is designed with a receptacle 11 into which the payment element 40 is inserted. In the present embodiment, a carrier 41 is included, and the payment element 40 is integrated into the same. The carrier 41 is accordingly matched to the geometric shape of the receptacle 11 of the housing 10 . When the carrier 41 is in the inserted state in the receptacle 11 according to FIG. 1 , the carrier 41 takes on a certain housing function. In addition, the receptacle 11 can be geometrically designed in various ways to reliably hold the carrier 41 with the payment element 40 in the housing 10 of the identification transmitter 1 . However, in all embodiments, the payment element 40 is inserted with the carrier 41 into the receptacle 11 in such a manner that the user can remove the payment element 40 from the receptacle 11 if needed. According to FIG. 1 , it can be contemplated that the communication means 31 is likewise used for the communication with the electronic payment system 6 , wherein said communication means 31 is also used for the communication with the communication means 3 on board the motor vehicle. As an alternative, it is also possible that a second communication means 43 is included in the mobile identification transmitter 1 for the communication with the electronic payment system 6 . In this case, the communication means 43 can be arranged on the housing 10 of the mobile identification transmitter 1 , for example. Similarly, it can be contemplated that the payment element 40 itself is designed having this communication means 43 . Likewise, it can be contemplated that the carrier 41 has the communication means 43 . [0029] In a further embodiment which is not explicitly illustrated, the payment element 40 can be removably attached independently in the receptacle 11 of the housing 10 . This means that the payment element 40 can be arranged on the housing 10 without a support, as according to FIG. 1 or FIG. 2 . For example, a slot, a window, an opening, etc. is constructed on the housing 10 according to the geometry of the payment element 40 such that the payment element 40 is reliably accommodated. If the user removes the payment element 40 from the housing 10 at this point, a corresponding closure is additionally included and is arranged separately on the housing, in order to reliably close the receptacle of the payment element 40 once again. [0030] The payment element 40 can have a chip, for example, including a microprocessor, circuit, storage device, etc., in order to carry out payment actions with the payment system 6 . This is shown schematically in FIG. 1 and FIG. 2 , for example. The payment system 6 can be positioned at a point of sale (POS), for example, wherein to ensure a cashless payment transaction between the buyer, the same carrying the mobile identification transmitter 1 for example, and a seller and/or a credit institute. In this case, the payment element 40 can have a credit card function and/or a debit card function, for example. In FIG. 1 , the payment element 40 with the carrier 41 is held in the receptacle 11 of the housing 10 , such that the identification transmitter 1 is in its normal state, wherein communication with the security system of the motor vehicle 2 and also communication with the payment system 6 are possible. The secure state 5 is shown in FIG. 2 , wherein a closure 20 is fastened in the receptacle 11 such that components such as contact elements 12 of the receptacle 11 , for example, the same being sensitive to disruption, are protected, whereby it is possible to prevent function disruptions. In this secure state 5 , communication is possible between the identification transmitter 1 and the security system of the motor vehicle; however, a payment action via the payment element 40 , the same being removed from the receptacle 11 , is not possible. [0031] In addition, it can be contemplated that an energy storage device 32 is included on the identification transmitter 1 in order to supply the necessary electronic components with current. FIG. 1 shows that the energy storage device 32 can be integrated into the housing 11 , for example, in order to supply the electronics 30 , including the communication means 3 , 43 , 31 , with current. Likewise, it is possible that a second energy storage device 33 is included which is directly integrated into the payment element 40 or is directly integrated into the carrier 41 . This second energy storage device 33 serves as a redundancy for the first energy storage device 32 . [0032] As shown is FIG. 1 and in FIG. 2 , the closure 20 is inserted in a receptacle 13 of the housing 10 , and according to the invention is in a passive position 8 . The active position 7 of the closure 20 is shown in FIG. 2 , wherein the closure 20 is fastened in the receptacle 11 . [0033] The closure 20 can be designed as a dummy plug which is designed with corresponding contact elements which can be plugged into the contact elements 12 of the housing 10 , wherein this dummy plug 20 is reliably held in the receptacle 11 and constitutes a reliable seal for the receptacle 11 . [0034] A further embodiment of the identification transmitter 1 according to the invention, as shown in FIG. 1 and FIG. 2 , is shown in FIG. 3 , wherein the closure 20 is fastened on the housing 10 via a cable 14 . The cable 14 can be designed as a flexible cable, for example. The remaining embodiments of the identification transmitter 1 , as in FIG. 1 and FIG. 2 , refer to the identification transmitter 1 shown in FIG. 3 . [0035] In FIG. 4 or FIG. 5 , the receptacle 11 is shown, wherein in FIG. 4 the closure 20 is a cap which can pivot about an axis 21 and which is under spring tension when in the passive position 8 . At this point, if the payment element is removed from the receptacle 11 as shown in FIG. 4 , the closure 20 simultaneously pivots counter-clockwise about the axis 21 , and reaches its active position 7 . This is shown by the dashed line in FIG. 4 . The contact elements 12 located in the receptacle 11 can therefore be effectively sealed-off and protected from the external environment. [0036] In FIG. 5 , the closure 20 can move translationally between its active position 7 and its passive position 8 . At this point, if the payment element 40 is removed from the receptacle 11 of the housing 10 , the closure 20 can be manually slid into the active position 7 (shown by a dashed line)—or this movement of the closure 20 into its active position 7 can be carried out automatically. This embodiment is particularly characterized by its compactness; and when the closure 20 is in the active position 7 , the contact elements 12 are simultaneously sealed-off and protected in the receptacle 11 . [0037] According to all embodiments, a corresponding seal can be included on the closure 20 and/or on the carrier 41 and/or on the wall of the receptacle 11 , in order to effectively seal-off the contact elements 12 , 42 and also the electronics 30 with their attached electronic components. This applies both for the normal state 4 and for the secure state 5 of the identification transmitter 1 . In addition, in all embodiments, the closure 20 can serve as an advertisement or information board on which information, and particularly a logo, letters, a combination of numbers, advertisement information, etc. can be applied, and particularly printed.

A mobile identification transmitter for activating a security system of a motor vehicle, particularly an access and/or ignition control system, having a housing in which electronics and a communication means are arranged, wherein the communication means can be brought into communication with a communication means of the security system on board the motor vehicle, a payment element is removably fastened in a receptacle of the housing, where a closure is separately arranged on the housing, the identification transmitter can be set in a normal state and in a secure state, in the normal state and in the secure state communication can be made with the security system, in the secure state the payment element is removed from the receptacle, and the closure seals and protects the receptacle.

big_patent

BACKGROUND [0001] An imaging device, such as a xerographic machine, becomes inactive when not in use. When the imaging device becomes inactive for a long period of time, the device is often put into a “sleep mode” in which most of the electric power is cut off to save energy. When the imaging device “wakes up” from the sleep mode, the device starts warming up and performs imaging operations with toner. SUMMARY [0002] The toner used in such an imaging device is charged with a tribo-electro-static charge (also known as tribo). A toner concentration (TC) sensor measures the concentration of the toner in the developer by detecting the tribo charge of the toner, and based on the output of the TC sensor, a toner dispenser may adjust the supply of toner to increase the concentration of the toner when the concentration of toner is low. [0003] If the imaging device is inactive for a long period of time, such as from the end of a business day to the next morning, the tribo charge of the toner may decrease. The tribo charge greatly affects the image quality in an imaging operation. Therefore, the image quality in an imaging operation after a delayed period may become inconsistent and darker than the image quality during normal or continual use. [0004] The exemplary embodiments address these and other issues. For example, in various exemplary embodiments, a method for charging a toner used in an imaging device may include determining one or more periods of inactivity of the imaging device, and charging the toner to a predetermined level based on the determined period of inactivity. [0005] In various exemplary embodiments, a method for charging toner used in an imaging device may include determining one or more periods of inactivity of the imaging device, measuring a toner charge level when the printing machine is recovered from the inactivity, and charging the toner to a predetermined level based on a difference between the measured charge of toner and a predetermined level. [0006] In various exemplary embodiments, an apparatus for charging a developer in an imaging device may include an inactivity determining section that determines one or more periods of inactivity of the imaging device, and a charging section that charges the toner to a predetermined level. [0007] In various exemplary embodiments, the above-described method and/or apparatus may be included in a xerographic machine. [0008] These and other features and advantages of the disclosed embodiments are described in, or are apparent from, the following detailed description of various exemplary embodiments. BRIEF DESCRIPTION OF THE DRAWINGS [0009] Various exemplary embodiments of disclosed systems and methods will be described, in detail, with reference to the following figures, wherein: [0010] FIG. 1 is a diagram showing an imaging device according to an exemplary embodiment; [0011] FIG. 2 illustrates a toner and developer supply system according to an exemplary embodiment; [0012] FIG. 3 illustrates a block diagram showing a toner charging system that charges the toner according to an exemplary embodiment; [0013] FIG. 4 illustrates a flowchart showing a flow of charging the toner according to an exemplary embodiment; and [0014] FIG. 5 illustrates a flowchart showing another flow of charging the toner according to an exemplary embodiment. DETAILED DESCRIPTION OF EMBODIMENTS [0015] In various exemplary embodiments, the tribo charge of toner is returned to the level of normal operation after recovering from the inactivity. Using an intelligent method for controlling the tribo charge of toner, problems in the related art developer encounters are overcome or reduced. In various exemplary embodiments, the imaging device discussed herein includes, but is not limited to, a printer, copier, fax machine and any other printing device that may be suitable according to the exemplary embodiments. [0016] While the present disclosure will be described in connection with exemplary embodiments thereof, it will be understood that it is not intended to limit the disclosure to any one embodiment. On the contrary, it is intended to cover all alternatives, modifications, and equivalents as may be included within the spirit and scope of the disclosure as defined by the claims. [0017] A structure of an exemplary printing device is described. Here, a black and white printing machine is described as an example. However, as described later, it is appreciated that a universal developer may be used in a multicolor printing machine as well. [0018] As shown in FIG. 1 , an exemplary printing machine 1 may include a photoreceptor belt 10 . The photoreceptor belt 10 may be supported by rollers 11 , 12 , 13 , and 14 . A motor 15 may operate the movement of the roller 14 , which in turn causes movement of the photoreceptor belt 10 in a direction, for example, indicated by an arrow 16 , for advancing the photoreceptor sequentially through the various xerographic stations. [0019] A portion of the photoreceptor belt 10 passes through a charging station A where a corona generating device 17 charges the photoconductive surface of the belt 10 to a relatively high, substantially uniform potential. The charged portion of the photoconductive surface is advanced through an imaging and an exposure station B. A document 18 may be positioned on a raster input scanner (RIS) 19 . One common type of RMS contains document illumination lamps, optics, a mechanical scanning drive, and a charged coupled device. The MIS captures the entire image from original document 18 and converts it to a series of raster scan lines. Alternatively, image signals may be supplied by an undepicted computer network. This information is transmitted as electrical signals to an image processing system (IPS) 20 . The IPS 20 converts image information into signals. [0020] The IPS 20 contains control electronics which prepare and manage the image data flow to a raster output scanning device (ROS) 21 , which creates the output copy image. When exposed at the exposure station B, the image areas are discharged to create an electrostatic latent image of the document. [0021] An exemplary developer station C, indicated generally by the reference numeral 100 (hereinafter referred to as a developer 100 ), advances development material into contact with the electrostatic latent image. The developer 100 may include a developer housing holding toner and a developer, i.e., carrier. The toner may be provided in a toner container 110 , and the developer may be provided in a developer container 111 . The toner container 110 and the developer container 111 may be installed on the developer station 100 . [0022] The complete developer in the developer container 111 may be added to the developer housing 100 prior to installing the toner container 110 . Once the developer has been added to the housing 100 , the empty developer container 110 may be removed. The toner container 110 may then be installed in the housing 100 . The toner dispensed from the toner container 110 and the developer dispensed from the developer container 111 are mixed in the developer housing 100 . [0023] FIG. 2 illustrates an exemplary structure of the developer housing 100 . As depicted therein, the developer housing 100 may include a developer roller 150 , a transport roller 152 , and a paddle wheel conveyor 154 . The developer roller 150 , transport roller 152 , and the paddle wheel conveyor 154 may be disposed in a chamber 156 of the developer housing 100 . As the toner and developer are dispensed from the toner container 110 and the developer container 111 , the mixture of the toner and developer may be dispensed over the paddle wheel conveyor 154 so as to be intermixed with the carrier granules contained therein, forming a fresh supply of developer material. [0024] The developer roller 150 includes a non-magnetic tubular member over a magnetic rotor and is rotated in the direction of arrow 162 . Similarly, the transport roller 152 may be made from a non-magnetic tubular member over a magnetic rotor and is rotated in the direction of arrow 164 . The exterior circumferential surface of the tubular member of the transport roller 152 may be roughened to facilitate developer material movement. [0025] The paddle wheel conveyor 154 may intermingle the fresh supply of toner particles with the carrier granules so as to form a new supply of developer material. The paddle wheel conveyor 154 may be made from a hub having a plurality of substantially equally spaced vanes extending radially outwardly therefrom and may be rotated in the direction of arrow 166 . In this way, the toner particles may be advanced to the transport roller 152 . With the rotation of the paddle wheel 154 , the transport roller 152 rotates and the developer roller 150 may move the developer material into a development zone 168 . In the development zone 168 , the toner particles may be attracted from the carrier granules to the electrostatic latent image recorded on a photoconductive surface 170 of a drum 117 . [0026] Referring again to FIG. 1 , the developer housing 100 may include a toner concentration sensor (TC sensor) 121 to monitor the concentration of the mixed toner and developer by detecting the tribo charge of the toner. If the TC sensor 121 determines that the concentration of the toner in the developer, a signal may be sent to a controller 122 , which may be used to increase the supply of the toner so as to adjust the concentration of the mixture to a predetermined amount. The concentration may be predetermined and color or system dependent. [0027] The photoreceptor belt 10 may then advance the developed latent image to transfer station D. At the transfer station D, a medium 24 , such as, for example, paper, is advanced into contact with the developed latent images on the belt 10 . A corona generating device 22 may charge the medium 24 to the proper potential so that it becomes tacked to the photoreceptor belt 10 and the toner powder image is attracted from the photoreceptor belt 10 to the medium 24 . After transfer, a corona generator 23 charges the medium to an opposite polarity to detach the medium from the photoreceptor belt 10 , whereupon the medium is stripped from the photoreceptor belt 10 . [0028] Sheets of the medium 24 may be advanced to a transfer station D from a supply tray 25 . The medium 24 is fed from tray 25 , with sheet feeder 26 , and advanced to the transfer station D along a conveyor 27 . After transfer, the medium 24 continues to move in the direction of an arrow 28 to a fusing station E. The fusing station E may include a fuser assembly 29 , which permanently affixes the transfer toner powder images to the medium. Then the medium 24 is ejected to a tray 30 through a path 31 . [0029] Residual particles remaining on the photoreceptor belt 10 after each copy is made are removed at a cleaning station F for the next round of use. Accordingly, the image on the original is transferred to the medium 24 at a proper level of darkness. [0030] Next, how the tribo charge of toner is adjusted is discussed. [0031] FIG. 3 illustrates an exemplary embodiment of an intelligent toner charging system. The controller 122 may include inactivity determining section 500 which may determine an activity of the machine 1 . The inactivity may be an idle period of the machine 1 in which the machine 1 is not used by a user and may be determined by the status of a printing operation. That is, if the user does not activate the machine 1 and if the machine 1 falls into an idle state, then the inactivity determining section 500 may determine that the machine is inactive. [0032] The activity and inactivity of the machine 1 may be monitored by the inactivity determining section 500 periodically or continuously at any time. Such activity and inactivity of the machine 1 may also be monitored at a predetermined time of the day as may be configured by the user. [0033] The relationship between the inactivity time and the tribo charge of the toner may be approximated by the following power law: [0000] Tribo charge=Steady state of tribo charge×idle time C [0034] where C is a constant dependent on age of the toner and relative humidity (RH). An exemplary value of C is −0.02. [0035] The inactivity determining section 500 may include a user usage pattern determining section 510 that determines a usage pattern of the user. For example, the user usage pattern determining section 510 may monitor the usage of the user during the day and determine the usage pattern, such as the time for the first and last usages of the day and any inactivity pattern during the day that exceeds a predetermined length of time. The user usage pattern determining section 510 may be “self learning” and may determine the user pattern using an adaptive algorithm. Such an adaptive algorithm may detect long periods of inactivity, record the time and day of the week associated with these, and group/weight similar times to predict user behaviour. For example, the adaptive algorithm may record times of cycle-in (wake-up) after inactivity of more than 1 hour as follows: 8:10, 12:59, 8:06, 12:49, 8:09, 11:04, 12:55, 8:00, 13:05, 16:05, etc on weekdays. The adaptive algorithm may find two groups of highly weighed times and average them: 8:06 and 12:54. Two other time records (11:04, 16:05) may not be sufficiently associated with other time records to be considered a predictor of future behavior. [0036] The user pattern may be determined from a collection of information of such usage by the user for a predetermined length of time, such as one or two weeks. The collected information may be recorded in a later-discussed storing section 560 . The learning period may be continuous, a fixed initial time, or a moving window examining recent usage and may be pre-configured based on typical office hours followed by learning based on a moving window covering the past 4-8 weeks. The user may also configure the predetermined length of time in advance. Additionally, an initial usage pattern may be configured in advance. [0037] The inactivity determining section 500 may also include a predicting section 520 that predicts the next user usage from the determination made by the inactivity determining section 500 . In other words, the predicting section 520 predicts when the user is expected to next use the machine 1 , based on a user usage pattern. For example, the predicting section 520 may predict the time for the first usage of the day by the user, by taking an average of recorded times of daily first usage. [0038] Details of such calculations are described in, for example, U.S. patent application No. ______ (Attorney Docket No. 130732), which is incorporated herein by reference in its entirety. [0039] The inactivity determining section 500 may also include a measuring section 530 that measures the TC sensor 121 . The measuring system 530 may measure the sensor level at various times during the usage of the machine, including during the cycle-in and cycle-out of the machine. [0040] The calculating section 540 calculates a decay of the tribo charge of the toner based on the difference between any two sensor levels of the TC sensor 121 . For instance, the calculating section 540 may calculate the decay using the sensor level at the beginning of the inactivity period and the sensor level at the end of the inactivity level, that is, when the machine 1 “wakes up” from a sleep mode. The calculating section 540 may also calculate a decay of tribo charge based on an equation to predict the tribo when “waking” from sleep mode. [0041] The inactivity determining section 500 may further include an updating section 550 and a storing section 560 . The updating section 550 updates information on the user usage pattern, the predicated next user usage, sensor levels measured by the measuring section 530 and the decay calculated by the calculating section 540 . The storing section 560 may store such information for future usage. [0042] Upon determination of the inactivity, a charging section 570 may instruct the machine 1 to charge the toner to a predetermined level that is suitable for performing a printing operation. The charging section 570 may instruct the machine 1 to charge the developer based on the decay calculated by the calculating section 540 . [0043] A performing section 580 may perform a printing operation after the developer is changed by the charging section 570 . In particular, the performing section 580 pre-runs the machine 10 to perform the printing operation to ensure that the developer is at an adequate charge level for normal printing. [0044] FIG. 4 illustrates a flow chart of a method for charging the developer. The process starts at S 1000 and continues to S 1010 . As shown at S 1010 , a determination may be made as to whether the machine 1 is inactive. The inactivity may be, for example, an idle period of the machine 1 in which the machine 1 is not used by a user and may be determined by the status of printing operation. [0045] If the machine 1 is not inactive, then the process repeats at S 1010 . Otherwise, the process makes a prediction of the next cycle as shown at S 1020 . For example, at step S 1020 , a determination may be made as to whether the user's predicted next usage has been reached. If the predicted user's next usage has not been reached, the process continues as shown at S 1030 . If the predicted user's next usage has been reached, the process continues as shown at S 1070 . [0046] More specifically, a determination may be made as to whether the machine 1 has awaken from a sleep mode, that is, whether the machine 1 is in operation, as shown at S 1030 . If so, the process continues as shown at S 1040 . If not, the process returns to the prediction cycle as shown at S 1020 . [0047] Furthermore, as shown at S 1040 , the idle time may be calculated, and then the user pattern may be determined from the idle time, as shown at S 1050 . That is, when the machine 1 became inactive and when the machine 1 was operated next, may be determined. The next user usage may be determined based on this user pattern and the previous user patterns. The user pattern may be determined using an adaptive algorithm. [0048] Then the user pattern and predicted next cycle may be stored in a storing section for future use, as shown at S 1060 . Then the process ends as shown at S 1100 . [0049] If the determination of the predicted next cycle, as shown at S 1020 is positive, that is, if the predicted next user's usage has been reached, then decay may be calculated from the inactivity period, as shown at S 1070 . For example, the tribo charge=steady state of tribo charge×idle time C , where C may be a constant dependent on age of the toner and RH. [0050] Then, the toner may be charged based on the calculated decay, and the machine 1 may pre-run the developer, as shown at S 1080 . The tribo charge of the toner may be measured, and a determination may be made as to whether the toner is charged to a predetermined level, as shown at S 1090 . If so, the process ends at S 1100 . If not, the process may return and repeat to charge the toner, as shown at S 1080 . [0051] FIG. 5 illustrates a flowchart of a second method for charging the developer. The process starts at S 2000 and continues to S 2010 . More specifically, the process begins when a determination is made as to whether the machine is inactive, as shown at S 2010 . The inactivity may be an idle period of the machine 1 in which the machine 1 is not used by a user and may be determined by the status of printing operation. If the machine 1 is not inactive, then the process as shown at S 2010 may repeat. [0052] If the machine 1 is inactive, then a sensor level of the TC sensor 121 may be measured and recorded, as shown at S 2020 . Then, a determination may be made as to whether the machine 1 has become active, as shown at S 2030 . If the machine 1 has not become active, then the process repeats, as shown at S 2030 . If the machine 1 has become active, then the sensor level of the TC sensor 121 may again measure and record, as shown at S 2040 . [0053] Next, a difference between the two sensor levels may be calculated to determine decay of the toner, as shown at S 2050 . That is, the change in the tribo charge levels may be determined. A determination may be made as to whether the difference between the two sensor levels is greater than a first value k 1 , as shown at S 2060 . The first value k 1 may be a threshold value to determine that the tribo charge of the toner is low enough to cause deficiency in the printed image. [0054] If the difference between the two sensor levels is not greater than the first value k 1 , the process may continue and perform normal marking operations, as shown at S 2070 . Then, the process may end as shown at S 2080 . [0055] If the difference is greater than the constant k 1 at S 2060 , the process may move to S 2090 . That is, the toner may be charged by a multiplication of a second value k 2 and the difference between the sensor levels, as shown at S 2090 . The value k 2 may be a constant to adjust the tribo charge of the toner to the predetermined charge level. Then, the process may continue to step S 2100 and may perform a marking operation. [0056] The toner optionally may again be charged by a multiplication of a third value k 3 and the difference between the sensor levels, as shown at S 2110 . This ensures that the toner has a tribo charge for the normal operation. Then, the process may end as shown at S 2080 . [0057] Either one of the above-described exemplary methods may be sufficient to adjust the tribo charge of the toner. However, it will be appreciated that both methods may be used as a combination to even more accurately adjust the tribo charge of the toner. [0058] The disclosed methods may be readily implemented in software, such as by using object or object-oriented software development environments that provide portable source code that can be used on a variety of computer or workstation hardware platforms. Alternatively, appropriate portions of the disclosed intelligent toner charging system may be implemented partially or fully in hardware using standard logic circuits or a VLSI design. Whether software or hardware is used is dependent on the speed and/or efficiency requirements of the system, the particular function, and the particular software or hardware systems or microprocessor or microcomputer systems being utilized. The processing systems and methods described above, however, can be readily implemented in hardware or software using any known or later developed systems or structures, devices and/or software by those skilled in the applicable art without undue experimentation from the functional description provided herein together with a general knowledge of the computer arts. [0059] It will be appreciated that variations of the above-disclosed and other features and functions, or alternatives thereof may be desirably combined into many other different systems or applications. Also, various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art, and are also intended to be encompassed by the following claims.

A method and apparatus for charging toner for an imaging device includes an inactivity determining section that determines one or more periods of inactivity of the printing machine, a measuring section that measures a charge of the toner, and a charging section that charges the toner to a predetermined level based on at least one of the determined one or more periods of inactivity and the measured charge of the toner. The toner is charged to a predetermined level after recovery from the inactivity period so that the tribo-electric charge of the toner is enhanced for normal printing without causing unwanted effects when the imagining device recovers from inactivity.

big_patent

BACKGROUND OF THE INVENTION [0001] The present invention relates to an apparatus capable of controlling with high precision the recording and reproduction of signals by plural heads, and more particularly to a recording/reproducing apparatus in which a recording/regenerative integrated circuit with plural magneto resistive heads (hereinafter abbreviated to MR heads) connected thereto can be controlled with high precision. The invention further relates to an apparatus for reproducing digital information signals or the like with MR heads, and more particularly to a rotary magnetic head type apparatus in which bias currents to MR heads mounted on a rotary drum can be appropriately controlled. [0002] An MR head, as it can detect magnetic information signals entered from a recording medium, such as a magnetic tape or a magnetic disk, by variations in resistance, requires the supply of a detecting current (sense current). Furthermore, as such variations in resistance have a nonlinear characteristic with respect to the input magnetic field, an MR head also needs a bias current for keeping the operating point in a more linear region. Recently developed MR heads are designed to these currents (hereinafter to be together referred to as bias currents) use in combination. [0003] Where MR heads are to be used in a rotary head type magnetic recording/reproducing apparatus, a bias current circuit and a preamplifier circuit are mounted on the rotary drum. Therefore, power to drive these circuits needs to be supplied to the rotary drum side, and it is usually transmitted via a rotary transformer or a slip ring (contact). Also, MR head bias current control signals are transmitted to the rotary drum side via the rotary transformer after being converted into A.C. signals, and further rectified on the rotary drum side to be converted into D.C. voltage signals for controlling the MR heads. [0004] A technique to mount MR heads on a rotary drum and control bias currents to determine the operating points of the MR heads is described, e.g. in J-P-A No. 177924/1998. Further, J-P-A No. 105909/1998 discloses a bias current regulating apparatus capable of flowing optimal bias currents to individual MR heads. J-P-A No. 201005/1995 reveals a method by which optimal bias currents are applied to active MR heads at the time of executing each head switching command. SUMMARY OF THE INVENTION [0005] For high density recording/reproducing apparatuses using a magnetic tape, the prevailing trend is to increase the number of magnetic heads (MR heads) mounted on the rotary drum in order to expand the capacity and enhance the transfer rate. Since each MR head differs in sensitivity and optimal operating point according to its element length from the sliding surface of the tape (MR height), it is preferable to individually optimize the bias current where plural MR heads are to be used. However, if it is necessary to provide the rotary transformer for controlling the MR bias currents with as many channels as the MR heads, it will become difficult to increase the number of MR heads to be mounted on the rotary drum. Furthermore, where control information is to be transmitted in analog signals, there will be another problem of difficulty to achieve high enough precision. [0006] An object of the present invention, therefore, is to provide a rotary magnetic head type apparatus permitting independent and precise regulation of bias currents supplied to plural MR heads mounted on a rotary drum in a simple structure. [0007] In order to achieve the object, a rotary magnetic head type apparatus according to the invention is provided on a stationary drum side with a control signal generator for generating control signals for controlling the operating amperages of magneto resistive heads and on the rotary drum side with a decoder circuit for discriminating data of the control signals and a current supply circuit for supplying operating currents to the magneto resistive heads in response to the output signals of the decoder circuit. The control signals are transmitted over a single channel of a rotary transformer and set the operating currents of the magneto resistive heads. Further, the control signals may include control information regarding a regenerative amplifier for reproduced outputs of the magneto resistive heads and recording current setting for recording heads. [0008] Otherwise, a regenerative integrated circuit comprising of a current supply circuit and a regenerative amplifier is mounted on the rotary drum to switch over among the plurality of MR heads for operation in turn. Usually a regenerative integrated circuit for MR heads is controlled with digital data on three lines including Data, Clock and Chip Select (CS) lines. For this reason, a control signal generator for generating control signals for controlling the regenerative integrated circuit is provided on the stationary drum side, a decoder circuit for discriminating data of the control signals is provided on the rotary drum side, and the three-line signals for controlling the regenerative integrated circuit are supplied from the decoder circuit. This structure requires only one control line for transmission from the stationary side to the rotary side even if the number of MR heads is increased. Moreover, since the transmitted signals are digital signals, highly precise transmission is made possible. [0009] However, since additional functions in such a regenerative integrated circuit would entail a substantial increase in the quantity of data bits required for their control, if data required for all the controls are transmitted on every occasion of head switching, it will take too long a time. In the worst case, head switching may fail to be done at the desired timing, inviting a loss of some head-reproduced signals. If the number of MR heads is increased and the number of regenerative integrated circuits mounted on the rotary drum also increases, a similar problem will arise because the data for the increased integrated circuits that are used are transmitted by time-division multiplexing. This is also true of controlling the plurality of recording heads in each recording integrated circuit. It is essential to perform head switching at the desired timing in a recording/reproducing apparatus provided with plural heads not only of the MR type but also of any type. [0010] Another object of the present invention is to provide a recording/reproducing apparatus permitting switching over among plural heads with high precision, in particular a rotary magnetic head type apparatus permitting switching over plural MR heads and recording heads mounted on a rotary drum at high speed. [0011] In order to achieve the object, a recording/reproducing apparatus according to the present invention is provided with a recording/reproducing unit for recording/reproducing signals onto/from a recording medium with plural heads, a generating unit for generating control data for controlling the recording/reproducing unit, and a transmitting unit for transmitting control data generated by the generating unit to the recording/reproducing unit, wherein data for controlling the switching over among the plurality of heads are transmitted with priority over other control data. BRIEF DESCRIPTION OF THE DRAWINGS [0012] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. [0013] [0013]FIG. 1 is a block diagram illustrating a rotary magnetic head type apparatus, which is a preferred embodiment of the present invention. [0014] [0014]FIG. 2 illustrates bias current supply circuits in the rotary magnetic head type apparatus shown in FIG. 1. [0015] [0015]FIG. 3 is a block diagram illustrating a rotary magnetic head type apparatus, which is another preferred embodiment of the present invention. [0016] [0016]FIG. 4 illustrates the control timing in a regenerative integrated circuit in the rotary magnetic head type apparatus shown in FIG. 3. [0017] [0017]FIG. 5 is a block diagram illustrating a rotary magnetic head type apparatus, which is still another preferred embodiment of the present invention. [0018] [0018]FIG. 6 is a block diagram illustrating a rotary magnetic head type apparatus, which is yet another preferred embodiment of the present invention. [0019] [0019]FIG. 7 illustrates rotary transformers in the rotary magnetic head type apparatus shown in FIG. 6. [0020] [0020]FIG. 8 illustrates rotary transformers embodied in another way in the rotary magnetic head type apparatus shown in FIG. 6. [0021] [0021]FIG. 9 illustrates in detail the control timing in the regenerative integrated circuit in the rotary magnetic head type apparatus shown in FIG. 3. [0022] [0022]FIG. 10 illustrates in detail the control timing in another way in the regenerative integrated circuit in the rotary magnetic head type apparatus shown in FIG. 3. [0023] [0023]FIG. 11 illustrates in detail the control timing in the regenerative integrated circuit in the regenerative integrated circuit and the recording integrated circuit in the rotary magnetic head type apparatus shown in FIG. 6. DESCRIPTION OF THE PREFERRED EMBODIMENTS [0024] Preferred embodiments of the present invention will be described in detail below. [0025] [0025]FIG. 1 is a block diagram illustrating a rotary magnetic head type apparatus, which is a preferred embodiment of the present invention. A pair of MR heads 201 and 203 are fitted on a rotary drum 1 in opposite positions 180° apart to read signals recorded on a magnetic tape (not shown) wound approximately 180° in the rotating direction of the drum. Current circuits 401 and 403 are circuits for flowing bias currents to take out signals from the MR heads 201 and 203 . A regenerative amplifier 5 is provided with a two-channel amplifier for the MR heads 201 and 203 . A rotary transformer 28 for transmitting data between the stationary side and the rotary side is provided with a rotary transformer for power 7 , a rotary transformer for reproduced signals 8 and a rotary transformer for control signals 9 . Information signals on MR head bias current data generated by a control signal generator 12 are transmitted to the rotary side via the rotary transformer for control signals 9 . A decoder 6 discriminates data of these signals, and controls the bias currents for the MR heads 201 and 203 by outputting control signals to the current circuits 401 and 403 . Information signals reproduced by the MR heads 201 and 203 from the magnetic tape, after being amplified by the regenerative amplifier 5 , are delivered to the rotary transformer for reproduced signals 8 and a buffer amplifier 11 to undergo signal processing. [0026] Although the output signals of the control signal generator 12 are transmitted by the rotary transformer for control signals 9 to the rotary side in the above-described embodiment, a slip ring, for instance, may be fitted to the shaft of the rotary drum to transmit the signals directly from the stationary side via a contact. However, considering the risk of error occurrence due to the insufficient reliability of the contact or noise during the long period of high-speed rotation, the above-described transmission of the control signals by the rotary transformer is more preferable. The decoder 6 can be configured of an ordinary digital integrated circuit or, if adaptable in operating speed, a general-purpose microcomputer may be used instead. The buffer amplifier 11 can be configured of a low input impedance circuit, such as a common-base circuit. [0027] Since such circuit components as the current circuits 401 and 403 , regenerative amplifier 5 and decoder 6 are mounted on the rotary side in the foregoing structure, a power supply circuit 3 is provided on the rotary drum 1 . The power supply circuit 3 , comprises of a rectifier circuit and a voltage regulator, and operates to obtain a desired D.C. voltage from the output A.C. signal of a power signal generator 10 transmitted via the rotary transformer for power 7 . For instance, if a final D.C. voltage of 5 V is desired, a switching signal of about 20 Vp-p, 100 kHz is generated from the stationary side D.C. source voltage of 12 V by the power signal generator 10 . Then, the rotary transformer for power 7 having a turns ratio of 1:1 and a half-wave rectifier circuit as the rectifier circuit are used to obtain a D.C. voltage of around 7 V. Further a 5 V D.C. voltage regulator can be operated. [0028] Another applicable method for power supply is to fit a slip ring or the like to the shaft of the rotary drum to transmit a voltage directly from the stationary side via a contact. In this case, as the high-speed rotation of the rotary drum 1 continues for a long period, insufficient reliability of the contact or noise might pose a problem. Therefore, the aforementioned power transmission using the rotary transformer is more preferable. [0029] In this embodiment of the invention, it is possible to switch the output signals of the decoder 6 at every 180° turn of the rotary drum 1 . Thus, one out of the MR heads 201 and 203 , what is on the operating side (what is in contact with the magnetic tape and reproducing signals), is individually controlled to position it on the optimal operating bias point. The control enables the two MR heads 201 and 203 to be controlled with outputs from the one-channel rotary transformer for control signals 9 and the single decoder 6 . In this case, the bias current to the non-operating MR head (not in contact with the magnetic tape) takes on the same amperage as that for the operating MR head. [0030] It is also possible to output at the same time a signal from the control signal generator 12 to switch over the regenerative amplifier 5 at every 180° turn. The decoder 6 discriminates data, switches over the regenerative amplifier 5 consisting of a two-channel amplifier, and chooses between the output signals of the MR heads 201 and 203 . The selected output signal is transmitted to the stationary side buffer amplifier 11 via the rotary transformer for reproduced signals 8 . This structure enables the output signals of the MR heads 201 and 203 to be transmitted by the single channel rotary transformer for reproduced signals 8 . [0031] As described above, according to the present invention, it is possible to independently control each of the bias currents for plural MR heads mounted on the rotary drum with a one-channel control signal sent from the stationary drum side, and let them operate at their respective optimal points. [0032] [0032]FIG. 2 illustrates bias current supply circuits 401 and 403 shown in FIG. 1. A current Miller circuit is configured of transistors 13 and 14 , resistors 17 and 18 , a diode 15 and a resistor 16 . It so operates that currents proportional to currents flowing to a transistor 19 and a resistor 20 flow to the MR heads 201 and 203 . The diode 15 is connected for temperature compensation for the transistors 13 and 14 . The decoder 6 discriminates information on bias currents for the MR heads 201 and 203 transmitted via the rotary transformer for control signals 9 , and transmits the discriminated data to a digital-to-analog (D/A) converter 21 . The D/A converter 21 converts the digital data into analog D.C. voltage signals, which are further converted by the transistor 19 and the resistor 20 into D.C. currents. Thus, the bias currents for the MR heads 201 and 203 can be controlled with the D.C. output voltage of the D/A converter 21 . Where the number of MR heads used in this embodiment is to be increased, as many circuits each configured of the transistor 13 and the resistor shown in FIG. 2 as the total number of heads are provided. Half as many D/A converters 21 as the total number of heads would suffice where two each out of plural MR heads are arranged opposite to each other at 180°. Where they are not arranged opposite at 180°, as many D/A converters 21 as the total number of heads can be provided. [0033] The embodiment illustrated in FIG. 3 is a version of what is shown in FIG. 1, the difference being that the regenerative amplifier 5 is integrated with the current circuits 401 and 403 to be together used as a regenerative integrated circuit 501 and an oscillator 22 is connected to the decoder 6 . The same components as in FIG. 1 are denoted by respectively the same reference numerals. The regenerative integrated circuit 501 is provided with a two-channel amplifier for the MR heads 201 and 203 , and its operating mode is controlled with data on three control lines including Data, Clock and CS lines. The control functions include, for instance, head (amplifier) switching, MR head bias current setting, regenerative amplifier gain setting, detection of thermal asperity (TA) noise peculiar to MR heads and correction. A register matching each function is selected in advance, and control data are written into it to determine its operating state and value. [0034] Information signals on the magnetic tape reproduced by the MR heads 201 and 203 are amplified by the regenerative integrated circuit 501 . After that, they are sent to the rotary transformer for reproduced signals 8 and the buffer amplifier 11 to undergo the following signal processing. The buffer amplifier 11 is configured of a low input impedance circuit, such as a common-base circuit. Information signals for the regenerative integrated circuit 501 generated by the control signal generator 12 are transmitted to the rotary side via the rotary transformer for control signals 9 , and subjected to data discrimination by the decoder 6 , which thereby controls the operation of the regenerative integrated circuit 501 . [0035] As the three different control signals of the regenerative integrated circuit 501 here are digital signal strings, the decoder 6 is also provided with the oscillator 22 for generating digital signals, and discriminates control data transmitted from the control signal generator 12 . Then, the decoder 6 operates to convert these data into digital control data for the regenerative integrated circuit 501 and output them in that form. This structure enables the three control lines to be used as they are even if the number of MR heads 201 and 203 further increases and additional regenerative integrated circuits 501 are provided. It has to be noted, though, that as many CS lines as the number of regenerative integrated circuits 501 that are used would be required. The oscillation frequency of the oscillator 22 is selected from a range of 20 to 30 MHz, though it depends on the type and number of regenerative integrated circuits 501 used. [0036] By controlling the operating mode in this way, each of the MR heads 201 and 203 can be controlled fully independently of each other. For instance, bias currents for two MR heads differing in MR height can be controlled to keep their respective optimal amperages. Also, the service life of an MR head as an element, as it is dependent on the product of the bias current amperage and the duration of current supply, can be extended by control to minimize the bias current for the MR head during the non-operating 180° period. Further, by switching the gain of the regenerative amplifier in 180° periods, the amplitude of the output signals of the regenerative integrated circuit 501 can be kept constant. [0037] [0037]FIG. 4 illustrates the control timing in the regenerative integrated circuit 501 . As illustrated, data signals are delivered to the three control lines including Data, Clock and CS immediately before the timing of head switching (signal varying point) to control the regenerative integrated circuit 501 . For instance, by changing head (amplifier) switching information data and MR bias current data on the Data line at every 180°, the bias currents for the MR heads 201 and 203 in contact with the magnetic tape and reproducing signals can be set to their respective optimal amperages. Further a desired one of the output signals of the MR heads 201 and 203 is selected by switching the regenerative integrated circuit 501 consisting of a two-channel amplifier, and it can be transmitted to the stationary side buffer amplifier 11 via the one-channel rotary transformer for reproduced signals 8 . [0038] Since the control data here for the regenerative integrated circuit 501 should include the address of the control register when they are transmitted, about 20 bytes or more of data are transmitted at every time of head switching. Therefore, transmission of all the data would take 10 μs of time or more, though it partly depends on the clock frequency of the decoder 6 . This period of time will lengthen with an increase in control data as the function of the regenerative integrated circuit 501 is enhanced and with an increase in the number of regenerative integrated circuits 501 . [0039] In such a state, as head switching fails to take place when it should, there will arise problems that some signals are dropped and signals are reproduced in a state where MR heads are not kept at their respective optimal operating points. In this embodiment of the invention, in order to prevent loss or wrong setting of data at the time of head switching, top priority in the transmission of digital data at the time of head switching is given to head switching signal data and MR current control signal data. [0040] The control timing in the regenerative integrated circuit 501 will now be explained in detail with reference to FIG. 9. In accordance with the operational timing shown in FIG. 4, head switching signal data and the address of their storage, e.g. the address of register A, are first transmitted. In the regenerative integrated circuit 501 , control varies immediately after the reception of data, and the operating regenerative amplifier is switched to that on the MR head 201 side. Then, operating current data for the MR head 201 and the address of register B in which they are to be stored are transmitted to place the MR head 201 in a state in which it can be operated by a normal current. Finally, the addresses of plural registers and corresponding data for controlling the amplifier gain, high-pass filter cut-off frequency and correction data for thermal asperity noise are transmitted. Thus, head switching signal data and operating current data are transmitted prior to all other data. At the next timing of 180° switching, the regenerative amplifier is controlled to be switched over to the MR head 203 side by a similar operation. Such data as the amplifier gain need not be transmitted at every time of head switching, but may be transmitted at the time of starting up the apparatus or when control becomes necessary. [0041] The control method describe above can prevent any reproduced signal loss due to an increase in head switching time and ensure stable data reproduction because the head switching operation performed at every 180° and the setting of the MR head operating current are finalized early. [0042] [0042]FIG. 10 illustrates in detail the control timing in another way in the regenerative integrated circuit 501 in this embodiment. [0043] This way of timing is the same as that in the embodiment shown in FIG. 9 in that head switching signal data and the address of register A into which they are stored are transmitted first, and operating current data for the MR head and the address of register B in which they are to be stored are transmitted second. In the embodiment of FIG. 10, the next data is allocated for reading the operating state of the regenerative integrated circuit 501 . Register C shown here stores, for instance, information on the result of detection of opening or short-circuiting of MR heads connected to the regenerative integrated circuit 501 and any abnormality in source voltage. The decoder 6 , contrary to the usual way, reads data from the regenerative integrated circuit 501 and re-encodes them, and transmits the data to the control signal generator 12 on the stationary side via the rotary transformer for control signals 9 . By this bidirectional communication, the states of the MR heads 201 and 203 on the rotary drum 1 can be detected from the stationary side. [0044] However, the above-described operation requires the addition of a bidirectional signal processing circuit to the decoder 6 and the control signal generator 12 . Or where these items of information are outputted from dedicated output terminals of the regenerative integrated circuits 501 and 502 instead of being supplied to the Data line, connection can be made directly to the decoder 6 . [0045] This embodiment permits transmission of the operating state of the regenerative integrated circuit 501 to the stationary drum side at every timing of head switching, and any faulty operation of the MR head 201 or 203 or occurrence of thermal asperity noise can be coped with in a short period of time. [0046] [0046]FIG. 5 is a block diagram illustrating a rotary magnetic head type apparatus, which is still another preferred embodiment of the present invention. In FIG. 5, the same components as in FIG. 1 and FIG. 3 are denoted by respectively the same reference numerals. In this embodiment, a pair of recording heads 231 and 233 in opposite positions 180° apart and a recording amplifier 24 with a two-channel output are mounted on the rotary drum 1 to perform recording and reproduction. The recording heads 231 and 233 are arranged in positions respectively 90° off the MR heads 201 and 203 . The heights between the heads are so determined that data tracks recorded on the magnetic tape by the recording heads 231 and 233 can be reproduced as they are by the MR heads 201 and 203 . The rotary transformer 28 is provided with a rotary transformer for recorded data 25 . Recorded data encoded by a recorded data generator 26 are transmitted to the rotary side via the rotary transformer for recorded data 25 . The recording amplifier 24 converts voltage information signals from the rotary transformer for recorded data 25 into currents, and supplies prescribed recording currents to the recording heads 231 and 233 . In this process, the amperages of the recording currents from the recording amplifier 24 are controlled by the decoder 6 . This operation is the same as the control method for the bias currents for the MR heads 201 and 203 described with reference to FIG. 1, and the current gain of the recording amplifier 14 can be varied with the D.C. output voltage of the decoder 6 . Further by selecting the channel output of the recording amplifier 24 at 180° intervals and keeping the recording amplifier 24 on the non-operating side in a non-recording state, the heat generation by the recording amplifier 24 mounted on the rotary drum can be reduced. [0047] This structure enables the recording heads 231 and 233 to record data and at the same time the MR heads 201 and 203 to reproduce data. For this reason, in the regulation to optimize the bias currents for the MR heads 201 and 203 relative to the recording characteristics of the recording heads 231 and 233 , there is no need to rewind the magnetic tape, making it possible to complete the regulation in a correspondingly shorter period of time. [0048] Although the recording amplifier 24 is mounted on the rotary side in this embodiment, it may as well be provided on the stationary side. However, its arrangement on the rotary side serves to halve the number of channels required for the rotary transformer for recorded data 25 and in this way smaller amplitude data signals would suffice for transmission to the rotary transformer for recorded data 25 , with the result that cross talk to the rotary transformer for reproduced signals 8 can be minimized. Although the mounting positions of the recording heads 231 and 233 are supposed to be at 90° with respect to the MR heads 201 and 203 in this embodiment, they may as well be at or around 0°. Their positions are not necessarily limited. [0049] [0049]FIG. 6 is a block diagram illustrating a rotary magnetic head type apparatus, which is yet another preferred embodiment of the present invention. The same components as in FIG. 1, FIG. 3 and FIG. 5 are denoted by respectively the same reference numerals. In this embodiment, there are provided four each of recording heads and MR heads, and two each of recording or reproducing heads are paired and constitute a double azimuth (DA) structure, in which they differ in azimuth angle from each other. This structure results in double as fast a data transfer speed as the rotary magnetic head type apparatus shown in FIG. 5. Pair combinations are recording heads 231 and 232 , 233 and 234 , MR heads 201 and 202 , and 203 and 204 . Further, the recording heads 231 , 232 , 233 and 234 and the MR heads 201 , 202 , 203 and 204 are arranged at 90° intervals, and the recording heads 231 and 233 , the recording heads 232 and 234 , the MR heads 201 and 203 and the MR heads 202 and 204 are mounted opposite to each other at 180°. [0050] Two sequences of data signals outputted at the same time from the recorded data generators 261 and 262 are recorded onto the magnetic tape via the pairs of rotary transformers for recorded data 251 and 252 , recording integrated circuits 241 and 242 , and recording heads 231 and 232 or 233 and 234 . At the time of reproduction, signals reproduced from the pairs of MR heads 201 and 202 or 203 and 204 are transmitted to buffer amplifiers 111 and 112 on the stationary side via regenerative integrated circuits 501 and 502 and rotary transformers for reproduced signals 801 and 802 . [0051] The recording integrated circuits 241 and 242 and the regenerative integrated circuits 501 and 502 , like their respective counterparts in the embodiment illustrated in FIG. 3, are controlled with three kinds of digital signals including Data, Clock and CS signals. In this embodiment, provided with two each of recording integrated circuits 241 and 242 and regenerative integrated circuits 501 and 502 , there are four CS lines of output signals from the decoder 6 . The regenerative integrated circuits 501 and 502 are provided with bias current supply circuits for the MR heads, and control the head switch and the amperages of bias currents for MR heads. In the recording integrated circuits 241 and 242 , the head switch and recording current amperages are controlled with three kinds of digital signals. [0052] These control data are generated by the control signal generator 12 , and transmitted to the decoder 6 via the one-channel rotary transformer for control signals 9 . The decoder 6 generates control data for the recording integrated circuits 241 and 242 and the regenerative integrated circuits 501 and 502 to handle these information data, and controls them via the six control lines. These output data signals are generated in accordance with oscillation clocks from the oscillator 22 connected to the decoder 6 . [0053] In this embodiment, the bias currents for MR heads 201 , 202 , 203 and 204 mounted on the rotary drum 1 can be regulated independently of one another. Further, as the recording integrated circuits 231 and 232 are controlled from the stationary side, setpoints of the recording currents for the recording heads 231 , 232 , 233 and 234 can also be regulated independently of one another. [0054] Here, if the Data line connected to the recording integrated circuits 241 and 242 and the regenerative integrated circuits 501 and 502 is a two-way path, for instance the terminal voltages of the MR heads, data on the occurrence of thermal asperity (TA) noise on the MR heads, the result of detection of opening or short-circuiting of heads can be delivered to the decoder 6 , and these items of information can be transmitted to the stationary side. This requires the addition of a bidirectional signal processing circuit to the decoder 6 and the control signal generator 12 , though. Or where these items of information are not outputted to the Data line, they can be inputted directly to the decoder 6 . [0055] Although the recording integrated circuits 241 and 242 and the regenerative integrated circuit 501 and 502 were described separately, they can be configured of a combined recording/reproducing integrated circuit, and the recording and reproducing functions can be switched over between each other using the aforementioned three control lines. [0056] [0056]FIG. 7 illustrates embodiments of rotary transformers in the rotary magnetic head type apparatus shown in FIG. 6. The rotary transformer 28 is provided with a rotary transformer for power 7 , a rotary transformer for control signals 9 , rotary transformers for recorded data 251 and 252 , and rotary transformers for reproduced signals 801 and 802 . In the slots of the rotary transformers, short rings 273 , 272 and 271 are inserted to reduce signal cross talk between the transformers. For this purpose, altogether nine such slots are provided. Although the rotary transformer 28 in the embodiment shown in FIG. 7 has a planar shape, it may as well be a coaxial cylinder instead. [0057] [0057]FIG. 8 illustrates rotary transformers embodied in another way in the rotary magnetic head type apparatus shown in FIG. 6. This is an instance in which, unlike the embodiment shown in FIG. 7, the rotary transformer 28 is separated into a first rotary transformer 281 having the rotary transformer for power 7 and the rotary transformer for control signals 9 and a second rotary transformer 282 having the rotary transformers for recorded data 251 and 252 and the rotary transformers for reproduced signals 801 and 802 . Compared with embodiment of FIG. 7, this embodiment permits a reduction in the number of slots per rotary transformer and the use of a rotary drum smaller in diameter. For this embodiment, too, a coaxial cylindrical rotary transformer may be divided into two parts. Alternatively, the first rotary transformer 281 may be planar and the second rotary transformer 282 may be cylindrical, or vice versa. [0058] [0058]FIG. 11 illustrates in detail the control timing in the embodiment shown in FIG. 6. [0059] As the recording system and the reproducing system are arranged 90° apart from each other, the control timing of the recording integrated circuits 241 and 242 and the control timing of the regenerative integrated circuits 501 and 502 are off each other by 90°. For both recording and reproducing, data are transmitted in the order of head switching signal data and amperage data. [0060] First at the timing of MR head switching, a CS 501 signal for the regenerative integrated circuit 501 is outputted at the pertinent timing shown in FIG. 11 to transmit the address of register A, in which head switching data for the regenerative integrated circuit 501 are stored, and data. At the next time slot, a CS 502 signal for the regenerative integrated circuit 502 is outputted at the pertinent timing shown in FIG. 11 to transmit the address of register D, in which head switching data for the regenerative integrated circuit 502 are stored, and data. At the further next time slots are allocated again for the MR head current data of the regenerative integrated circuit 501 and for the MR head current data of the regenerative integrated circuit 502 to output CS 501 and CS 502 signals at the respective timings. [0061] Similarly at recording head switching timings differing by 90° in phase, first a CS 241 signal for the recording integrated circuit 241 is outputted at the pertinent timing shown in FIG. 11 to transmit the address of register E, in which head switching data for the recording integrated circuit 241 are stored, and data. At the next time slot, a CS 242 signal for the recording integrated circuit 242 is outputted at the pertinent timing shown in FIG. 11 to transmit the address of register F, in which head switching data for the recording integrated circuit 242 are stored, and data. At the further next time slots are again allocated for the recording head current data of the recording integrated circuit 241 and for the recording head current data of the recording integrated circuit 242 to output CS 241 and CS 242 signals at the respective timings. [0062] Data which need not be transmitted at every time of head switching including, for instance, the amplifier gain, high-pass filter cut-off frequency and switching data for a thermal asperity noise compensating circuit are allocated collectively to an area for transmission. As stated above, by outputting the signals in this area only at the time of starting up the apparatus or as required, the occurrence of data errors due to the infiltration of communication noise can be prevented. [0063] In this embodiment, as head switching is given priority in every recording or regenerative integrated circuit, erroneous recording of signals and failure to reproduce signals can be prevented. Incidentally, in the foregoing description of this embodiment, the recording integrated circuits 241 and 242 and the regenerative integrated circuits 501 and 502 were supposed to be separated, they can as well be configured in combined recording/regenerative integrated circuits, and the recording and reproducing functions can be switched over between each other using the aforementioned three control lines. Further, though the mounting positions of the recording heads 231 and 233 are supposed to be at 90° with respect to the MR heads 201 and 203 in this embodiment, they may as well be at or around 0°. Their positions are not necessarily limited. [0064] As hitherto described, the present invention makes possible early finalization of head switching and operating current setting. This helps prevent failure to reproduce signals and erroneous recording due to a delay in head switching, resulting in stable data recording and reproduction. Further according to the invention, it is possible to control the decoder and the regenerative integrated circuit via a single control line (having a rotary transformer or transformers and the like). Since it is difficult to increase the number of rotary transformers in a rotary magnetic head type apparatus, the invention can be applied with particular effectiveness. This does not mean, however, that the invention can be applied only to rotary magnetic head type apparatuses, but it can also be effectively applied to disk apparatuses. [0065] Further, although the foregoing description supposed the use of digital signals as recorded/reproduced information signals, the applicability of the invention is not limited to digital signals, but the invention can also be applied to the transmission of frequency-modulated analog signals. [0066] Also, where MR heads are used, not only head switching data but also data for controlling bias currents have to be transmitted at the time of head switching, the invention embodied as described is particularly useful. However, the application of the invention is not confined to apparatuses provided with MR heads, but can also cover other types of apparatuses in which plural heads are controlled by a recording/ regenerative integrated circuit or circuits. [0067] Where integrated circuits are used as in the embodiments described above, the increased numbers of functions and of integrated circuits result in a substantial increase in the quantity of necessary data, the invention can be applied with particular effectiveness. However, even where no integrated circuit is used, the application of the invention can help prevent erroneous operation due to a delay in data transmission at the time of switching over between plural heads. [0068] The present invention is not limited to the above embodiments and various changes and modifications can be made within the spirit and scope of the present invention. Therefore, to appraise the public of the scope of the present invention, the following claims are made.

A recording/reproducing apparatus capable of switching over among a plurality of heads with high precision, wherein the apparatus is provided with: a recording/reproducing unit for recording/ reproducing signals onto/from a recording medium with a plurality of heads; a generating unit for generating control data for controlling the recording/reproducing unit; and a transmitting unit for transmitting control data generated by the generating unit to the recording/reproducing unit, wherein priority is given in transmission to data for controlling the switching of the plurality of heads over other data.

big_patent

BACKGROUND OF THE INVENTION This invention is concerned with locating and tracing concealed elongated conductive objects, such as pipes or cables, and is more particularly concerned with improved locating and tracing of a first object when a second object is adjacent to the first. In the prior art, there are two general techniques of locating buried metallic objects. A passive technique employs a gradiometer or the like as a magnetic locator for detecting the presence of ferrous metal objects, such as iron and steel pipes, iron markers, manhole covers, well casings, etc. An active technique uses a transmitter to induce alternating currents in non-ferrous metal pipes, power cables, or communication cables, for example, and a receiver to sense magnetic fields associated with the currents. The model MAC-51B Magnetic and Cable Locator manufactured by the assignee of the present invention is designed for selective active or passive use. When apparatus of this type is employed to locate and trace a cable (or non-ferrous pipe), for example, a transmitter may be disposed on the ground at a position close to the location (or suspected location) of a portion of the cable so as to induce an alternating current therein that may be traced by moving a receiver back and forth over the ground. When there are no interfering objects close to the cable being traced, this system works admirably, producing a distinct single null in the output signal of the receiver when the receiver is located directly over the cable and is oriented so as to sense a vertical component of a circumferential magnetic field associated with the current in the cable. When, however, another cable (or pipe) is present adjacent to the first cable, e.g., within a few feet of the first cable and extending in the same general direction, the single null output signal characteristic of the receiver becomes distorted, and tracing of the desired cable may become difficult. BRIEF DESCRIPTION OF THE INVENTION The present invention provides a system and method that improves substantially the ease and accuracy of locating and tracing of one concealed object, such as a buried pipe or cable, in the presence of an adjacent object. In one of the broader aspects of the invention, a system for locating at least one of a pair of concealed, elongated, conductive, adjacent objects, comprises, in combination, a transmitter and a receiver, said transmitter having means including a pair of antennae for inducing a pair of distinguishable alternating currents in said objects, respectively, said receiver being movable relative to said transmitter and to said objects, having means for sensing magnetic fields associated with said currents, respectively, and having means for producing an output signal dependent upon the sensing of both of said fields. In another of the broader aspects of the invention, a method of locating at least one of a pair of concealed, elongated, conductive, adjacent objects comprises producing in said objects a pair of distinguishable alternating currents, respectively, moving with respect to said objects a receiver sensitive to a pair of magnetic fields associated with said currents, respectively, and producing an output signal from said receiver dependent upon the sensing by said receiver of both of said fields. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be further described in conjunction with the accompanying drawings which illustrate preferred (best mode) embodiments, and wherein: FIGS. 1 and 2 are diagrammatic views illustrating the use of prior art apparatus in locating and tracing a buried cable; FIG. 3 is a diagrammatic view illustrating an output signal characteristic when a prior art receiver encounters a pair of adjacent cables (or pipes); FIG. 4 is a diagrammatic view illustrating transmitting apparatus in accordance with the invention; FIG. 5 is a diagrammatic view illustrating an optimum position of the transmitting apparatus with respect to a pair of buried pipes or cables; FIG. 6 is a view similar to FIG. 3 and illustrating an improvement in the output signal characteristic due to the invention; FIG. 7 is a view similar to FIG. 5 but illustrating the transmitting apparatus in a non-optimum position; FIG. 8 is a view similar to FIG. 6 and illustrating the output signal characteristic for the disposition of the transmitting apparatus in FIG. 7; FIG. 9 ,is a block diagram of transmitting apparatus employed in the invention; FIG. 10 is a block diagram of receiving apparatus employed in the invention; and FIG. 11 is a diagrammatic view illustrating a modification of transmitting antennae orientation. DESCRIPTION OF PREFERRED EMBODIMENTS FIG. 1 illustrates, diagrammatically, the use of the aforesaid model MAC-51B Cable Locator to locate and trace a buried cable (or pipe) C. A transmitter T with a loop antenna A is placed on the ground over a portion of the cable C (a portion that is known or located experimentally) and generates an electromagnetic field F that is coupled to the cable C and that induces in the cable an alternating current. The current has a circumferential field F' associated therewith that is sensed by a receiver R moved back and forth over the ground by an operator O. Apparatus of this type is well known and need not be described in detail. As shown in FIG. 2, in which the cable C extends perpendicular to the plane of the drawing, when the receiver R is held vertically (so as to sense a vertical component of the field F') and is moved back and forth across the cable C (three positions of the receiver being illustrated), an output signal characteristic S is produced having a null N directly over the cable and two lobes L and L' at opposite sides of the cable. By sweeping the receiver back and forth across the cable while moving along the general direction of the cable, the position of the cable may be readily traced. When a second cable (or pipe) C' is present adjacent to the first as shown in FIG. 3, the output signal characteristic S may be distorted so that the null N is located between the cables and one of the side lobes has a substantially greater amplitude than the other. The configuration of the output signal characteristic depends, for example, upon the depth of the second cable C' relative to the first cable C, the distance between the cables, and their relative size and conductivity. Thus, when two cables are present, running generally in the same direction, tracing of the desired cable may become difficult. The present invention alleviates this problem to a substantial degree, as will now be described. As shown in FIG. 4, the invention employs a transmitter T' having a pair of antennae A' and A" that are preferably spaced a few feet apart (say 3-5 feet), that are driven by RF signals, and that generate corresponding magnetic fields F1 and F2. Each of the antennae A' and A" may comprise 100 turns of No. 14 wire wound on a 1/2 inch by 8 inch ferrite rod, for example. As described in more detail hereinafter, the signals that drive the antennae are distinguishable, and the fields F1 and F2 induce corresponding distinguishable currents in cables C and C', respectively. As shown in FIG. 11, the orientation of the antennae may be changed from the horizontal orientation shown in FIG. 4 to enhance the inducement of currents in the respective cables. The transmitting apparatus is optimally positioned relative to the cables as shown in FIG. 5. Sometimes sufficient information as to the location of at least part of the cables is available to permit such positioning initially. At other times, however, such information is not available, and the transmitting apparatus may be initially positioned as shown FIG. 7, i.e., centered over one of the cables, or even completely beside the cables. Usually, sufficient information is available to determine at least the approximate location of a portion of a cable (or pipe) to be located and traced. After initial tracing, using a receiver R of the type referred to earlier, for example, the position of the transmitter may be moved to the position of FIG. 5 to optimize further tracing operations. As described hereinafter in more detail, the system of the invention is capable of producing two distinct output signal nulls N and N' over respective cables C and C', as shown in FIG. 6. It is thus possible to locate and trace one of the cables (or even both cables) more easily and accurately than with prior art systems and methods. As is apparent in FIG. 6, lobes L and L' are located at opposite sides of the cable C, and although these lobes may have different amplitudes, the null N is readily perceived. When the transmitting apparatus is located as shown in FIG. 7, the output signal characteristic may have the configuration shown in FIG. 8, in which one of the lobes L', is substantially distorted. By moving the location of the transmitting apparatus in the direction of the distorted lobe L', it is possible to arrive at the position shown in FIG. 5 and to produce an output signal having the characteristic shown in FIG. 6. The output signal characteristics shown in FIGS. 6 and 8 may be shifted upwardly or downwardly with respect to a base line by adjustment of a receiver deadband control, for example. When the receiver R is employed to trace a cable C in the presence of an adjacent cable C', the receiver will normally be swept back and forth across both cables to facilitate the desired positioning of the transmitter and to monitor the total output signal characteristic as the receiver is moved in the general direction of the cable(s) to be traced. In accordance with the invention, output signal characteristics of the type shown in FIGS. 6 and 8 are produced only when the receiver senses both fields associated with the currents in the respective cables, which are distinguishable. Among the techniques that may be employed to make the currents distinguishable from one another and to produce an output signal dependent upon the presence of both currents are: (1) currents having different carrier frequencies that may be combined to produce a beat frequency, (2) currents having the same carrier frequency amplitude-modulated by different frequencies that may be combined to produce a beat frequency, and (3) currents that are pulsed at different repetition rates that may be combined to produce a beat frequency. Other techniques may also be employed to distinguish the currents in the respective cables and to produce an output signal dependent upon the presence of both currents. As shown in FIG. 9, in a first embodiment the transmitter T' has carrier generators t and t' that produce sinusoidal carrier currents of 82.300 KHz and 82.682 KHz, for example, which drive antenna A' and A", respectively. The carrier frequencies when detected in the receiver R, will produce a beat frequency signal of 382 Hz. To produce a pulsating audio output signal which is easier for the operator to distinguish from background noise than a steady tone, each of the carrier frequencies may be pulsed on and off at a 6 Hz rate, for example, by a pulse generator t". FIG. 10 illustrates a typical receiver employed in the invention (which may be similar to the receiver of the model MAC-51B Magnetic and Cable Locator referred to earlier). The fields associated with the currents in the cables C and C', for example, are sensed by a sensor coil 10 (which may be wound upon a ferrite core) producing a combined signal that is supplied to an 82.5 KHz amplifier 12. The amplified signal is detected in an 82.5 KHz detector (demodulator) 14. The amplifier 12 amplifies both the 82.300 KHz and the 82.682 KHz carrier components in the combined signal from coil 12, and the detector 14 (a non-linear circuit) detects the envelope of the amplified signal and produces a 382 Hz beat frequency signal (pulsating at 6 Hz) when both components are present. A filter 16 passes the 382 Hz beat frequency signal to a variable gain amplifier 18, and the amplified beat frequency signal is applied to a 382 Hz detector 20. A 6 Hz pulsating signal from detector 20 (a non-linear circuit) is passed by a low pass filter 22 to a voltage controlled oscillator 24, which produces a variable frequency signal that is amplified by an audio amplifier 26 to produce a pulsating output signal that is supplied to a speaker 28. If, instead of using different carrier frequencies to drive the respective antennae A' and A", the same carrier frequency is used, both currents may be amplitude modulated by the same 382 Hz modulation frequency but pulsed at different and asynchronous pulse rates, such as 20.12 Hz for one antenna and 23.87 Hz for the other. The two signals will blend in the receiver and produce 20.12 Hz or 23.87 Hz pulsations of a 382 Hz signal at the output of detector 20 when a signal from only one cable is present and will produce a beat frequency signal of 3.75 Hz at the output of detector 20 when signals from both cables are present. Thus, if the low pass filter 22 is set to reject frequencies above 4 Hz, for example, an output signal from the speaker 28 will only be produced when currents in both cables are sensed by the receiver. As a further alternative, the same 82.5 KHz carrier (pulsed on and off at 6 Hz, for example) may be employed for both antennae but modulated at 1288 Hz and 906 Hz, respectively, which will produce a pulsating beat frequency signal of 382 Hz at the output of detector 14 when the currents in both cables are sensed. This signal may be processed as in the first embodiment. The invention is especially useful in an environment in which the horizontal separation s between the cables is related to the depth d of the cable to be located and traced in accordance with the relationship s<11/2d. The effect achieved by the invention is enhanced by the fact that the field from the transmitter, and hence the excitation at a cable, decreases by the inverse cube of the distance between an antennae and a cable. For example, if the cables and the antennae were each separated horizontally by 3 feet and the cables were buried 3 feet, then a signal due to a given antenna in a cable under that antenna would be 2.8 times stronger than a signal due to that antenna in a cable 3 feet to one side of the antenna. This phenomenon substantially reduces the inducement of currents from both antennae in the same cable when the transmitter is properly positioned. It also enhances the desired performance of the receiver, which may be optimized by adjustment of a threshold sensitivity control (indicated in FIG. 10). While preferred embodiments of the invention have been shown and described, it will be apparent to those skilled in the art that changes can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims. For example, the transmitter may be designed so that only one of the antennae may be energized (e.g., by a modulated 82.5 KHz carrier as in the aforesaid Model MAC-51B) for cable locating and tracing when only a single cable is present.

Locating and tracing of a concealed, elongated, conductive object, such as a buried pipe or cable, is enhanced, when a second such object is adjacent to the first, by employing a transmitter having a pair of antennae that induce distinguishable currents in the respective objects. A receiver movable with respect to the transmitter and with respect to the objects produces an output signal dependent upon the sensing of fields associated with both currents. The position of the transmitter relative to the objects is adjusted to optimize the output signal.

big_patent

CROSS-REFERENCE TO RELATED APPLICATION This application contains subject matter related to subject matter disclosed in U.S. Patent application Ser. No. 388,133, filed on this date and assigned to the assignee of the instant invention. Claims directed to the embodiment of FIG. 3 are contained in one application in the names of one inventive entity, while claims directed specifically to the embodiment of FIG. 4 in the names of another inventive entity are contained in the other related application. BACKGROUND OF THE INVENTION This invention relates to an apparatus for interfacing a speaker phone with a telephone network to permit hands-free automatic answering and communication. More particularly, this invention relates to such an apparatus for providing an automatic answering capability for the hands-free feature to interconnect, upon actuation of a selector switch, an incoming telephone call to a speaker phone. The invention also relates to such an apparatus which includes a timer for controlling the length of time of such interconnection and a bypass switch for bypassing the timer. It is known in the art to provide a hands-free answer capability which enables a telephone subscriber to answer an incoming call without physical manipulation of the telephone handset. Examples of such systems are shown in U.S. Pat. No. 4,172,967 which discloses a telephone system which includes an automatic answering provision with a hands-free feature, wherein the incoming call activates a speaker phone, or combination loudspeaker and microphone, and wherein termination of the call is under control of a timer. Another such system is shown in U.S. Pat. No. 4,063,047 which discloses such a telephone system with a multilink hands-free answer circuit while U.S. Pat. No. 3,743,791 discloses a voice actuated answering system. In the main, systems of the prior art have been directed to the telephone communication side of the system and it is feature of this invention to provide a device which can be used on or in connection with a private telephone line or switchboard extension with a telephone speaker phone. Such total hands-free answering and conversational capability is particularly advantageous for the physically handicapped or for an outpatient during a period of convalescence to respond to an inquiry from trained hospital personnel using a system such as that described in U.S. Pat. No. 4,237,344. Furthermore, hands-free conversation is advantageous for persons whose activities make handling a telephone difficult or dangerous. Such individuals include those having wet or soiled hands, such as an employee of a laundry, cooks, hairdressers, automobile mechanics or those people whose tasks require the use of both hands as a part of the work task or who have limited movement in a particular area, such as a secretary, laboratory technician or the like. Thus, it is an overall objective of this invention to provide a simplified, portable, readily connectable, automatic answering service for automatically interconnecting incoming telephone calls with a speaker phone to permit two-way communication by the recipient with the use of a minimum amount of circuitry and with a simple connection. Moreover, it is an aspect of the invention to provide such a feature as a modular package capable of being moved to various telephone jack locations throughout a particular installation, thus minimizing the capital expenditure of the user while maximizing the versatility of the unit. Still further, it is desired to provide such a system with a minimum of component parts in a way which is safe, reliable, and low in cost while high in convenience. These and other objectives of this invention will become apparent from a review of the written description of the invention which follows, taken in conjunction with the accompanying claims and drawings. BRIEF SUMMARY OF THE INVENTION Directed to achieving the aforestated objects of the invention and overcoming the problems of the prior art, this invention relates to an apparatus for interfacing a two-way speaker device with a telephone network. The apparatus includes a source of power for the interfacing apparatus, such as by the use of a transformer connected to a wall outlet in a home. Selective switch means are provided for selectively connecting, when actuated, the interfacing apparatus with the telephone network to permit telephone operation in either a conventional manner or in an automatic answering mode. When in the automatic answering mode, a coupler is provided for automatically coupling the telephone network to the speaker device to receive incoming telephone calls on the speaker device when the selector switch is actuated. Two embodiments of the interfacer are disclosed. The first embodiment of the interfacer includes an optically coupled circuit for coupling the telephone ringing circuit in a manner which discharges a charging capacitor to a predetermined signal level. Means are responsive to the discharge of the capacitor to a predetermined signal level to connect the speaker phone to the telephone lines automatically in a hands-free manner in response to the telephone ringing signal. Preferably, such an optocoupler includes a blocking capacitor at the input thereof for blocking DC components of the ringing signal from the optocoupler to permit cycling of the discharge of the charging capacitor. A timer is connected in circuit with the output of the optocoupler for limiting the time duration during which the telephone network is coupled to the speaker phone. A reset switch is provided in cooperation with the timer for canceling the predetermined time cycle in the timer upon command. In the alternative, the timer can be bypassed by operating a selector switch so that the coupling is extended until that switch is again actuated. In the alternative embodiment, the ringing signal is provided to a neon lamp optically coupled with a photocell having a resistance inversely proportional to the amount of light incident on the cell. As the light increases and the resistance of the photocell decreases, the current through a photocell relay increases to latch contacts to couple the speaker phone to the telephone line. A timing and extension feature as in the previous embodiment are also provided. BRIEF DESCRIPTION OF THE DRAWINGS In the drawings: FIG. 1 is a pictorial illustration of the portable components of the apparatus according to the invention for providing an automatic telephone answering capability through a speaker phone for an incoming telephone call; FIG. 2 is block diagram showing the essential components for providing the various modes of operation of the alternative embodiments; FIG. 3 is a detailed circuit and wiring diagram for the electronic embodiment of the apparatus according to the invention; and FIG. 4 is a detailed circuit diagram of an alternative, electromechanical embodiment of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A pictorial illustration of the components of the portable hands-free telephonic interfacing system according to the invention, designated generally by the reference numeral 10, is shown in FIG. 1. The system includes a conventional telephone handset 12 connected by the telephone conductor 13 through a modular plug 14 to a modular T-adapter 16 secured to a telephone wall jack 18 in a conventional manner. The incoming telephone lines are connected to the wall jack 18 to receive and transmit telephone calls through the available telephone network. The operation of such a conventional telephone system is well known in the art. A two-way speaker phone unit 20 is provided to permit hands-free speaking and listening communication with the telephone network when interconnected according to the invention with an interfacer device 22 according to the invention. As is well known, a two-way speaker phone includes at least a microphone, for conveying the voice signals of the call recipient, and a loudspeaker, for transmitting the voice signals of the initiating caller. The interfacer device 22 operates, when actuated, to answer an incoming call automatically and to switch the incoming call to the speaker phone unit 20 so that a two-way conversation may proceed. The interfacer device 22 includes a timing means which has the capability of turning off the speaker-phone unit at the end of an adjustable preset interval to terminate the telephone conversation. The interfacer device 22 also includes means to override the timing means to extend the call by actuating an extend switch 24 on the panel of the device 22. A light indicator 25 is also provided on the panel of the interfacer 22 to indicate the state of actuation of the extend switch, so that the user knows whether the call will be of a fixed or indeterminate length of time. The device also includes means for switching the device into and out of circuit with the telephone line by actuating a switch 28 on the face of the panel. The switch 28, with an associated indicator 29, permits either regular operation of the telephone system or automatic operation commanding the use of the speaker phone 20 for the predetermined or extended times mentioned above. When the switch 28 is in its regular position, the incoming call is answered in a normal manner by uncradling the handset of the telephone 12. A call indicator 30 is also provided on the panel to indicate visually the presence of an incoming call. The speaker phone 20 is connected by a conductor 32 to a modular plug 34 (for example, a Model No. RJ 11C connector) in turn connected to a modular in-line connector 35. Similarly, the interfacer device 22 is connected by a conductor 37 to a modular plug 38 (for example, also a Model No. RJ 11C). The telephone lines are connected to the interfacer unit 22 by telephone conductors 39 connected to the telephone system through the telephone wall jack 18, the modular T-adapter 16 and the modular plug 40. Power is provided to the interfacer device 22 through a transformer 42 connected to a local source of power (not shown), which provides an output on the order of 6 to 12 volts DC, connected by a power cord 43 and a plug jack connector 44. The modular nature of the system shown in FIG. 1 and its capability of simple connection to an existing telephone system through an available wall jack permits such systems to be temporarily installed, at a particular location, if desirable. For example, such a system can be used during a period of convalescence of an outpatient to receive on a hands-free basis incoming calls from medical personnel periodically inquiring on the status of the condition of the patient. In a business environment, as another example, the system can be quickly installed at conference or meeting sites to permit participants to receive incoming calls automatically with a minimum of interruption and permit hands-free communication. Even for permanent installation, the simple connections of FIG. 1 reduce installation cost and inconvenience, among other advantages. FIG. 2 is a block diagram of the components of the system. As can be understood from FIG. 2, the interfacer 22 couples the incoming telephone lines 46 and hence the incoming call to a speaker phone 20 permitting hands-free two-way communication depending on the regular or automatic position of the interfacer selector switch 28. When in the regular position, the incoming call is routed on line 47 to the telephone 12 in a conventional manner. When the switch 28 is in the automatic position, the incoming call, which is answered automatically, is either limited for a predetermined duration by a timer 48 or the timer may be bypassed so that the time of the incoming call is extended by an extension circuit 49. A preferred embodiment of this invention is directed to an electronic system which comprises the interfacer device 22. In the related application, the device includes an electromechanical system for achieving the features of the invention. A circuit and wiring diagram of the electronic embodiment of the interfacer device 22 is shown in FIG. 3. Where appropriate, the same reference numerals are used for like components shown in FIGS. 1 and 2. The telephone line 39 is connected to the input leads 39a and 39b, which at the output of the device are connected to the speaker phone 20. The transformer conductor 43 is connected to the leads 43a and 43b to provide power to the input of the interfacer device 22. The telephone line 39a and the transformer line 43a are connected to the input terminals of the switch 28 for commanding either regular or automatic operation, with the switch 28 shown in its regular operation position. An optocoupler 60 has its input in circuit with the telephone lines 39a and 39b, and its output in circuit with the input of the timer circuit 48, the function of which will be described in greater detail hereinafter. When the transformer 42 is in circuit with its input power line, such as when it is plugged in, the transformed output power is provided on lead 43a to an input at the 8-pin of the timer circuit 48 directly through lead 62 and through its associated components. Specifically, the 2-pin of the timer 48 is connected to the connection between a resistor 63 and a charging capacitor 64, which connection is also connected through a fixed resistor 65 and a variable resistor 66 to an output of the optocoupler 60. Both the 6-pin and the 7-pin of the timer 48 are connected to the connection between a capacitor 67 and series-connected fixed resistor 68 and variable timing resistor 69. The series circuit of the resistor 63 and the charging capacitor 64 is connected between the conductor 43a and the grounded lead 43b, while the series circuit of the resistor 68, variable resistor 69, and capacitor 67 is similarly connected between these same two lines. The 1-pin of the timer 61 is directly connected to the grounded lead 43b. The 4-pin output of the timer is connected to the junction between a fixed resistor 70 and a hang-up switch 71, the series combination of which is connected between the leads 43a and 43b. The 3-pin output of the timer 48 is connected to a diode 72. With power thus applied to the timer 48, the charging capacitor 64 begins to charge through the resistor 63 and initially triggers the timer to provide an output signal through the diode 72 to the coil 73a of a relay 73 having its contactor 73b connected in series in the telephone line 39a. At the same time, that output signal actuates an indicator 74, such as a light, through a resistor 75, showing that the unit is on power. With the switch 28 in its automatic position, the indicator 77 (for example, a light) is lighted through the resistor 78 and lead 79 to indicate that the speaker phone 33 is coupled to the telephone line, when the switch 28 is in its automatic position. The hang-up switch 71 acts to reset the timer and release the relay contactor 73b by effectively connecting, when closed, the 4-pin of the timer 48 to ground. When the interfacer device is in its automatic mode, with the switch 28 in its automatic position, the indicator 77 is on, and the optocoupler 60 is connected to the telephone lines 39a and 39b through the input leads 80 and 81. The lead 80 is connected to the 2-pin of the optocoupler 60 through a blocking capacitor 82 while the lead 81 is connected to the 1-pin of the optocoupler 60 through the resistor 83. A diode 84 is connected between the 1- and 2-input pins of the optocoupler 60 at the output sides of the resistor 83 and capacitor 82. When the telephone lines 39a and 39b are inactive, a DC voltage appears across them which is blocked by the capacitor 82 from triggering the optocoupler 60. When an AC ringing voltage appears across the telephone lines 39a and 39b in the conventional manner, the diode 84 shunts the negative voltage away from the light emitting diode (LED) included in the optocoupler 60 and the capacitor 82 and the resistor 83 effectively limit the current through the LED. The ringing voltage necessary to trigger the optocoupler 60 is approximated by the identity: V.sub.R =796/f.sub.R +39.2 (1) where: V R is the ringing voltage, and f R is the frequency of the AC signal. When the ringing voltage actuates the optocoupler 60, the charging capacitor 64 begins to discharge through the resistors 65 and 66 to the 5-pin of the optocoupler 60 and from its 4-pin to the grounded lead 43b through line 87. When the ringing ceases, the charging capacitor 64 begins to recharge through the resistor 63. The charge and discharge cycling thus causes a delay in actuation of the timer 48. The period of delay before the timer 48 is triggered is controlled by the variable resistor 69. When the cycling discharge of the charging capacitor 64 causes it to reach a voltage level sufficiently low at the 2-pin to trigger the timer 48, the coil 73a of the relay is actuated and the indicator 74 is actuated. At the same time, the charging capacitor 67 begins to recharge through the resistors 68 and 69. Adjustment of the variable resistor for the embodiment shown will permit up to about 82 seconds to complete the conversation on the speaker phone 33, unless the timer 48 is reset by actuating the hang-up switch as previously described. If desired, the period of conversation may be extended indefinitely by actuating the extend switch 24 connected in series with the oppositely-poled diodes 90 and 91 between the lead 79 and the ground lead 43B. When closed, the switch 24 also actuates the indicator 92 connected through the resistor 93 to the junction between the switch 24 and the diode 90. When the extend switch 24 is actuated, the transformed power on the line 79 is provided directly to the coil 73a to hold the relay contactor 73b closed while bypassing the timer circuit. And, the extend switch is only operative to bypass the timer when the switch 28 is in its automatic position. As thus described, the interfacer device according to the invention permits the following modes of operation when interfacing a conventional telephone network with a two-way speaker phone: (1) Regular operation by the telephone network without connection of the speaker phone, when the selector switch is in its regular position. (2) Automatic connection of a two speaker phone permitting hands-free communication through the speaker phone when the selector switch is in its automatic position to answer incoming calls. (3) Termination of such calls at the end of an adjustable predetermined time. (4) When in the automatic position, bypassing the timing circuit to permit extended conversation by closure of an extend switch. (5) Manual cancellation of the timed conversation by actuation of a hang-up switch to reset the timing circuit. The following components and values are capable of implementing the preferred embodiment of FIG. 3: Resistor 83: 75K Diode 84: 1N914 Capacitor 82: 0.1 μf, 200 V. Optocoupler 60: 4N46 IC Resistor 66: 5K Resistor 65: 1K Capacitor 64: 47 μf Capacitor 67: 15 μf Resistor 63: 75K Resistor 68: 1K Resistor 69: 5M Timer 61: 555 ICC Resistor 70: 1K Diode 72: 1N4001 Diode 90: 1N4001 Diode 91: 1N4001 Resistor 93: 220Ω Resistor 75: 220Ω Resistor 78: 200Ω FIG. 4 is an embodiment for practicing the invention by using electromechanical techniques. Where appropriate, like reference numerals have been included to identify like components. In FIG. 4, a source of power is provided to input terminals 43a' and 43b' from a source such as a transformer 42 in FIGS. 1-3. A switch 28 includes a leg in circuit with the telephone lines 39b and 39a respectively as in FIG. 3. A series connected coupling circuit is provided between the telephone lines 39a and 39b for optically coupling a high brightness neon light 101 in circuit with a fixed resistor 102, a capacitor 103, and a variable resistor 104 to a photocell 106. With the unit in the automatic mode when the switch 28 is in its automatic position and the timer switch 24 is in its timed position, the light 77 is illuminated and the interfacer 22 is ready to accept the call. As an incoming call generates an analog sequence on the telephone lines 39, the AC ringing voltage appears which is fed to the neon lamp 101 through the series circuit shown. The light produced by the neon lamp 101 is aimed at and optically coupled with the photocell 106 having a resistance which is inversely proportional to the amount of light present. The potentiometer 104 is used to vary the charge and discharge time of the capacitor 103, thus to vary the period of lighting of the neon light 106 for each ring. As the resistance of the photocell 106 decreases, the current flowing through a photocell relay 108 connected in series therewith between the leads 43a' and 43b' increases. When the threshold of operation of the photocell relay 108 is reached, its contacts 108a pull in, latching itself to couple the speaker phone to the telephone lines. It can be seen that the contactor 108a is in an operative circuit with the photocell relay coil 108 in circuit with the telephone line 39a as well as with the hang-up switch 110 and the timed delay relay coil 112. At the time that the contact 108a is closed, power is supplied to the indicator 77 and the timed delay 112 now begins its timing cycle. After a predetermined period of a time, contacts on the contactor 112a controlled by the time delay relay 112 open according to the timed potentiometer in the timed relay 112. After the timing period, power is removed from the photocell relay and the unit returns to the automatic mode. If desired, the timing period may be shortened by depressing the hang-up switch 110 and it is also possible to extend the length of the conversation indefinitely by placing the switch 24 in the extend position. When so positioned, power is supplied to the photocell relay through the diodes 116 and 118 to thus actuate the indicator 92. Components suitable for practicing this embodiment are as follows: Neon lamp 101: NE51H Resistor 102: 33K Capacitor 103: 1 μf, 200 V. Resistor 104: 10K Didode 116: IN4001 Diode 118: IN4001 Resistor 122: 470Ω Resistor 123: 470Ω Resistor 124: 470Ω The invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the claims rather than by the foregoing description, and all changes which come within the meaning and range of the equivalents of the claims are therefore intended to be embraced therein.

An apparatus for interfacing a speaker phone with a telephone network includes switch means for selectively connecting said interfacing apparatus with a telephone network to permit either conventional or automatic answering. A coupler, responsive to ringing signals on the telephone lines discharges a charging capacitor to a level sufficient to cause the automatic, hands-free interconnection of the speaker phone with the telephone line. In one embodiment, a timer is provided for limiting the length of time during which the speaker phone is coupled to the telephone line. A reset switch is provided in cooperation with the timer to permit the timing cycle to be reset upon command, thereby to shorten the time of connection if desired. The system operates in either a timed or extended mode. To bypass the timer and indefinitely extend the time during which the answered call is coupled between the telephone lines and the speaker phone, an extend switch is also provided to override the timer. In an alternative embodiment, the ringing voltage on the telephone line is optically coupled to an electromechanical circuit controlled by a photocell.

big_patent

FIELD OF THE INVENTION The present invention relates to the field of optical fiber communications, and more particularly to system network design and incorporation of branch powered amplification within such networks. BACKGROUND OF THE INVENTION The emergence, development, and maturation of a practical optical fiber amplifier over the past decade has generated unprecedented expansion in the overall capabilities of undersea lightwave communications systems. As a result, transmission capacities for digital data have swiftly jumped by an order of magnitude, now reaching values in excess of 5 Gb/s. Moreover, new applications of wavelength-division-multiplexing technologies stand poised to raise undersea system capacities by another order of magnitude. Today, the effort to expand and optimize point-to-point capacity in undersea transmission systems is receding in importance and the focus is shifting to other networking concerns. Prominent among these is the need to develop more reliable undersea lightwave systems that provide multipoint-to-multipoint connectivity. More precisely, there is a need to develop undersea networks in which all nodes remain optically connected in the event of an undersea cable cut, since such cuts represent the most common type of fault in undersea communications systems. One general architectural feature known to enhance a network's survivability in the event of a cable fault is to configure the communications trunk in a ring topology. A communications trunk ring has the straightforward feature of remaining in a single piece in the event of a cable cut; maintaining connections at all trunk ring nodes despite an arbitrary single cable cut. Another feature enhancing network survivability is the use of trunk and branch structures within a communication system. A cable cut in the branch of such a system isolates a single network node only, but other branches along the trunk remain operable. A network that combines a trunk and branch structure with a ring geometry, will therefore exhibit strong survivability features in that (i) an arbitrary single trunk cut leaves all nodes connected and therefore no branch is isolated and communications along the entirety of the trunk and branch network remain intact; and (ii) any number of simultaneous branch cuts simply isolate the corresponding branches, preventing continued communications along those branches, but allowing all other communications to remain enabled within the trunk ring and further allowing access to the trunk by the remaining unsevered branches. However, one substantial obstacle to building the robust trunk and branch ring network described above tends to be the cost of the required undersea optical repeaters, which are used for signal amplification. It is therefore desirable to develop a communications system which reduces the number of undersea repeaters that are required. SUMMARY OF THE INVENTION The present invention is a system for reducing or eliminating undersea optical repeaters in a trunk and branch ring network by replacing repeaters with remotely pumped optical amplifiers and remotely supplying energy to those optical amplifiers over the same branch cables that also distribute communications signals. An optical fiber cable trunk is configured in ring topology with one or more telecommunications hub serially interconnected therein. The hub is an access point to the optical fiber cable trunk by a major switching office, such as a regional switching office, which routes communications onto or from the cable trunk. Also coupled serially along the optical fiber cable trunk are one or more branching units. Branching units are optical coupling devices which allow for convenient add/drop points for telecommunications traffic from the cable trunk. Connected to the branching unit is a branch fiber optic cable which in turn is optically coupled at its other end to a cable station. A cable station accesses one or more of the signal wavelengths transported along the cable trunk. A cable station is bilateral in that communications signals are both sent to the cable trunk and retrieved from the cable trunk at this point. The present invention utilizes the branch fiber optic cable, along which communications signals are transmitted and received, to further unidirectionally transmit optical energy at a wavelength other than that of signal wavelength. The optical energy is used as a power source for an optical amplifier, which is located in the branch fiber optic cable, the optical fiber cable trunk, or the branching unit. Signal amplification is thereby provided without the use of conventional optical repeaters. A similar arrangement is also provided at the telecommunications hub, thereby allowing optical energy at a wavelength other than signal wavelength to be coupled onto the optical fiber cable trunk, to be transported along the hub with any existing optical communications signals, and to provide the energy necessary for signal amplification, all originating from the hub location. The hub is remotely located from the optical amplifier. The combination of hub assemblies optically connected via a telecommunications cable trunk in a ring topology, with cable stations extracting and inserting trunk communication signals through branch fiber optic cables and further, those same branch fiber optic cables serving to deliver light energy to remotely located optical amplifiers, has the following advantages: (i) a single optical fiber cable trunk cut maintains full connectivity along the tunk and to all cable stations via their respective branch fiber optic cables; (ii) branch fiber optic cable cuts simply isolate the associated cable station without compromising ring integrity, this aspect being especially important since branch fiber optic cable cuts are more susceptible to failure by severing since they are typically located in shallower water than the optical fiber cable trunk; (iii) by virtue of its trunk and branch structure, such networks respect the sovereignty concerns that often arise in undersea communications networks; (iv) such networks are not restricted to fixed wavelength routing schemes, accommodations may be made to allow for reconfigurable wavelength add/drop branching units; and finally (v) repeaterless technology incorporating remote pumping of an optical energy source through the network's branch fiber optical cables, may be utilized as a means of reducing the capital costs as well as the operating and maintenance costs of communications networks. BRIEF DESCRIPTION OF THE DRAWINGS A more complete understanding of the present invention may be obtained from consideration of the following description in conjunction with the drawings in which: FIG. 1 is a block diagram of a repeaterless trunk and branch fiber optic ring network, incorporating the essential structures supporting and powering in-line optical amplifiers; FIG. 2 is a block diagram of a branch assembly; and FIG. 3 is a block diagram of a repeaterless branch powered fiber optic communication system segment. DETAILED DESCRIPTION Although the present invention is particularly well suited as an undersea application of a repeaterless trunk and branch wavelength-division-multiplexing (WDM) optical fiber communications ring network, and shall be described so with respect to this application, the present invention, as disclosed, can be applied to other methods of signal multiplexing and may also be used as a terrestrial communications system instead of in an undersea application. A block diagram representing the preferred embodiment of the present invention, generally indicated by the reference numeral 100, is provided in FIG. 1. The illustrated preferred system 100 includes four branch assemblies 110, a hub assembly with remote pumping 120, a hub assembly without remote pumping 125, each serially coupled by an optical fiber cable trunk 130 and configured in a ring topology. The present invention, however, is not limited by the number of each component incorporated within the system. For example, it is only required that the network contains at least one branch assembly 110 and at least one hub assembly, either with remote pumping 120 or without remote pumping 125. Referring to FIG. 1, hub assembly with remote pumping 120 consists of a hub 185 coupled to both "ends" of the optical fiber cable trunk 130, so as to maintain ring topology continuity. It should be noted that, although only one fiber is shown for the optical fiber cable trunk 130 for the purpose of simplicity of explanation, in application there are generally a plurality individual fibers contained within the optical fiber cable trunk 130. Also optically coupled to the optical fiber cable trunk 130 is a light emitting power source 190, in this illustrative embodiment, through the hub 185 itself. The precise point at which the light emitting power source 190 is coupled to the optic fiber cable trunk 130 is not of imperative importance. The light source can also be coupled directly to the cable trunk 130 itself, either at a location separate and distinct from the hub 185, or coupled coterminously with the hub onto the optical fiber cable trunk 130. Located serially downstream the optical fiber cable trunk 130, and remotely located from the coupled hub 185 and the coupled light emitting power source 190, is an optical amplifier 180. The optical amplifier 180 typically consists of an erbium doped fiber which is able to amplify an attenuated telecommunications signal, converting the energy of an injected light source to produce signal amplification. The hub 185 represents a typical large "regional clearinghouse" or "regional switching office" for communications signals destined to be extracted from or inserted onto the optical fiber cable trunk 130. The hub 185 is the location where telecommunications traffic is aggregated, groomed and routed, eventually to be coupled onto the optical fiber cable trunk 130. The hub 185 accepts telecommunications signals from local switching offices or from other colloquial telecommunications systems destined to be placed on the optical fiber cable trunk 130 and converts them to optical signals if necessary, multiplexes the optical signals, amplifies the resulting composite optical signal, and transfers the optical signal, containing all the original telecommunications information, onto the optical fiber cable trunk 130. For communications signals which are already present on the trunk and must pass through the hub 185 to get to their ultimate destination, the hub 185 first demultiplexes the optical signal, converts the signal to electrical signals, amplifies the electrical signals, reconverts the electrical signals to optical signals and finally multiplexes the optical signals prior to insertion back onto the optical fiber cable trunk 130. The preferred embodiment of the present invention contemplates that the optical signal transmitted along the optical fiber cable trunk 130 is a wavelength-division-multiplexed (WDM) signal, however, other forms of multiplexing are also contemplated, such as time-division-multiplexing. Also, the contemplated wavelengths for network optical signals is in the range of 1500-1600 nanometers (nm), since this wavelength band offers a window of low attenuation losses for transmission along a single mode fiber optic cable, however, other wavelengths and other types of fiber optic cable may also be chosen. Light emitting power source 190 is coupled onto the optical fiber cable trunk 130, either through the hub 185 itself or directly onto the optical fiber cable trunk 130. If coupled directly onto the optical fiber cable trunk 130, the coupling may be accomplished either coterminously with the coupling for the hub 185, or at some point along the optical fiber cable trunk 130 between the hub 185 and the optical amplifier 180. The present invention utilizes a multiple order cascaded Raman laser, producing an output light source with a wavelength in the range of 1450-1500 nm, although other light sources and other wavelengths may be used. However, there are two constrictive requirements regarding the choice of light source and its corresponding wavelength. They are that (i) the laser chosen must be capable of producing light at a wavelength that ultimately can be used as an energy source for the intended optical amplifier 180 and (ii) the wavelength of light chosen must be distinct from the band of signal wavelengths contemplated for transmission along the optical fiber cable trunk 130. Optical amplifier 180 is an erbium doped fiber amplifier. Although other optical fiber amplifiers may be chosen, the greatest success in amplifying signals in the 1500-1600 nm range is with erbium doped fiber amplifiers. The optical amplifier 180 is spliced or coupled with the optical fiber cable trunk 130. Its exact location, related as the distance of optical fiber length between the optical amplifier 180 and the light emitting power source 190, is to be determined by the network designer. The requirements for determining its placement are well known to those skilled in the art. Components currently available limit the maximum distance between the light emitting power source 190 and the optical amplifier 180 to about one hundred kilometers (km), but as more powerful light emitting power sources and fiber optic cables with lower attenuation and phase dispersion become available, this maximum distance will become greater. WDM multiplexed telecommunications traffic along the optical fiber cable trunk 130 passes between the hub 185 to the optical amplifier 180 bidirectionally. This may be accomplished by dedicating a specific fiber within the optical fiber cable trunk 130 to transmission of all wavelengths in one direction only, and designating another fiber within the optical fiber cable trunk 130 to transport signal wavelengths in the opposite direction. Alternatively, a single fiber within the optical fiber cable trunk 130 may transport signals at one wavelength is an assigned direction, and transport signals at another wavelength in the opposite direction. Additionally and concurrently, the optical energy from the light emitting power source 190 is also being transferred from the hub 185 to the optical amplifier 180, at a wavelength other than the wavelengths of the WDM multiplexed signals. The erbium doped fiber amplifier 180 converts the energy delivered from the light emitting power source 190 and converts that energy into amplified telecommunications signals. The amplified signals then continue along the optical fiber cable trunk 130. Other telecommunication hubs may be serially coupled within the optical fiber cable trunk 130. Additional telecommunications hubs may or may not include remote pumping and amplification. The embodiment as shown in FIG. 1 reveals one other hub assembly 125 incorporated within the ring trunk. Hub assembly without remote pumping 125 contains only one component element, the hub 195. The hub 195 performs exactly as described above regarding hub 185 incorporated into a hub assembly with remote pumping 120. Again referring to FIG. 1, four branch assemblies 110 are incorporated into the network. In other embodiments of the present invention, as would be obvious to one skilled in the art, there may be as few as one branch assembly 110, or a plurality of branch assemblies 110, the exact number desired to be determined by the network designer. Branch assemblies 110 are convenient add/drop locations for telecommunications signals along the optical fiber cable trunk 130. A block diagram of one branch assembly 200 is illustrated in FIG. 2. The branch assembly consists of a cable station 210 and a light emitting power source 220, each optically coupled to a branch fiber optic cable 230. In turn, the branch fiber optic cable 230 is optically coupled to a branching unit 240. The branching unit 240 maintains optical fiber cable trunk 250 continuity and is also optically coupled to the branch fiber optic cable 230. An optical amplifier 260 is shown serially embedded within the optical fiber cable trunk 250. It should be noted that, although only one fiber each is shown for the branch fiber optic cable 230 and the optical fiber cable trunk 250 for the purpose of simplicity of explanation, in application there are generally a plurality individual fibers contained within both. Cable station 210 is a typical medium sized "local clearinghouse" or "local switching office" for communications signals destined to be extracted from or inserted onto the optical fiber cable trunk 250. The cable station 210 is the location where at least one wavelength, of the various optical signal wavelengths present on the optical fiber cable trunk 250, is either received from other local switching offices for eventual incorporation and transmission over the optical fiber cable trunk 250, or alternatively, is extracted from the optical fiber cable trunk 250 for eventual dissemination through the cable station 210 to a local telecommunications destination. The cable station 210 may process one signal wavelength or more, depending on the volume of telecommunications traffic anticipated in the local area in proximity to and serviced by the cable station 210. Therefore, the cable station 210 can include multiplexing/demultiplexing equipment if it is desired to process a plurality of optical wavelength signals destined for or extracted from the WDM telecommunications signals of the optical fiber cable trunk 250. The contemplated wavelength for optical signals accumulated at and disseminated from the cable station 210 is in the range of 1500-1600 nanometers (nm), corresponding to the band of wavelengths previously selected for transmission along the optical fiber cable trunk 250, since this wavelength band offers a window of low attenuation losses for transmission along a single mode fiber optic cable. However, the present invention is not restricted to these wavelengths alone. A branch fiber optic cable 230 is optically coupled to the cable station 210. The branch fiber optic cable 230 transports bidirectional optical communications signals between the cable station 210 and the optical fiber cable trunk 250. As applied in the present configuration as an undersea telecommunications network, the branch fiber optic cable 230 is predominantly submerged. Much of the submerged branch fiber optic cable 230 is located in shallow water, being a branch from the optical fiber cable trunk 230 to the land based cable station 210, and is therefore particularly susceptible to damage from commercial boating and shipping. The optical fiber cable trunk 230 is typically located more than one hundred miles from the coastline and is therefore not as susceptible to failure. The branch fiber optic cable 230 is coupled at its other end to a branching unit 240. The branching unit 240 is a coupling device, well known to those skilled in the art, used to maintain continuity along a fiber optic cable run, and simultaneously allow a convenient location to insert new signals onto or extract existing signals from that fiber optic cable run. The branching unit 240 is also known as an add/drop node. In the present embodiment, branching unit 240 maintains continuity along the optical fiber cable trunk 250 and simultaneously allows for insertion of new signals and extraction of existing signals via the branch fiber optic cable 230. The branching unit 240 bilaterally passes a discrete signal wavelength or wavelengths onto or from the branch fiber optic cable 230 and allows signals of other wavelengths to pass through the branching unit 240 and continue along the optical fiber cable trunk 250 to its ultimate destination. In the present embodiment, a branching unit 240 is selected which is tunable. That is, the optical signal wavelengths that are diverted and branched to and from the branch fiber optic cable 230 are adjustable. This feature allows for system network reconfiguration as cable station 210 processing components are added, deleted, upgraded, or otherwise changed. A key element of the present invention concerns the light emitting power source 220, which is coupled onto the branch fiber optic cable 230, either through the cable station 210 itself or directly onto the branch fiber optic cable 230. If coupled directly onto the branch fiber optic cable 230, the coupling may be accomplished either coterminously with the coupling for the cable station 210, or at some point along the branch fiber optic cable 230 between the branching unit 240 and the cable station 210. In the preferred embodiment, the light emitting power source 220 is coupled to the branch fiber optic cable 230 coterminously with the cable station 210 coupling. This allows the light emitting power source 220 to be physically located at the land based cable station 210 and obviates the need for a second fiber optic cable run to transport the light emitting power source's energy to the branch fiber optic cable 230. The energy of the light emitting power source 220 is transferred unidirectionally over the branch fiber optic cable 230, which also simultaneously transports the bidirectional optical telecommunications signals. The energy is coupled through the branching unit 240 onto the optical fiber cable trunk 250, to be used in the optical amplifier 260 as the energy source to amplify attenuated optical fiber cable trunk 250 communication signals. By so doing, amplification of attenuated signals is achieved using solely passive repeaterless components without the requirement of additional optical fiber cable runs. The light emitting power source 220 utilized is similar to the light emitting power source used previously in conjunction with the hub assembly. The present invention utilizes a multiple order cascaded Raman laser, producing an output light source with a wavelength in the range of 1450-1500 nanometers (nm), although other light sources and other light sources and other wavelengths may be used. However, there are two constrictive requirements regarding the choice of the light source and its corresponding wavelength. They are that (i) the light source chosen must be capable of producing light at a wavelength that ultimately can be used as an energy source for the intended optical amplifier 260 and (ii) the wavelength of light chosen must be distinct from the band of signal wavelengths contemplated for transmission along the branch fiber optic cable 230 and the optical fiber cable trunk 250. An optical amplifier 260 is serially coupled and embedded in the optical fiber cable trunk 250. The optical amplifier 260 utilized in the present embodiment is an erbium doped fiber amplifier. Although other optical fiber amplifiers may be used, erbium doped fiber amplifiers currently offer the greatest efficiency and performance in the 1500-1600 nm range of wavelengths. The optical amplifier 260 is either coupled or spliced and then sealed within the optical fiber cable trunk 260. The exact location of the optical amplifier 260 along the optical fiber cable trunk 250 is not crucial. The optical amplifier 260 may also be coupled at the branching unit 240, or within the branch fiber optic cable 230. However, it is crucial to design the branch assembly 200 so that total cable distance between the optical amplifier 260 and the light emitting power source 220 is not so great that the quantum of energy which is being transmitted is completely or effectively attenuated prior to reaching the optical amplifier. Currently, the maximum effective distance between an erbium doped fiber amplifier and a Raman laser supplying energy to that fiber amplifier over single mode optical fiber is approximately one hundred kilometers (km). This limitation exists because current single mode fibers have attenuation losses of about -0.2 dB/km (decibels per kilometer). If transmitted over one hundred kilometers, a total energy loss of minus twenty decibels occurs, or one per cent of its initial energy. However, as optical fiber with lower attenuation constants are manufactured, more powerful light sources are developed, and more effective optical amplifiers become available, the limiting distance between light emitting power source and optical amplifier will become much greater. As stated earlier, the optical amplifier does not need to be coupled in the optical fiber cable trunk. FIG. 3 illustrates a repeaterless branch powered fiber optic communications system segment 300. Included in the system segment 300 are a cable station 310, a light emitting power source 320, a branch fiber optic cable 330, and an optical amplifier 340. It should be noted that, although only one fiber is shown for the branch fiber optic cable 330 for the purpose of simplicity of explanation, in application there are generally a plurality individual fibers contained within the branch fiber optic cable 330. The system segment 300 represents a portion of the branch assembly previously discussed, except that the branch fiber optic cable 330 contains the erbium doped fiber amplifier. The cable station 310 is optically coupled with the branch fiber optic cable 330 and transmits and receives optical communications signals passing thereover. A light emitting power source 320 producing energy at a wavelength other than at signal wavelength is coupled to the same branch fiber optic cable 330. As before, the cable station and light emitting power source are coupled coterminously. Thus the same branch fiber optic cable 330 unidirectionally transmits energy from the power source 320 at a wavelength other than the signal wavelength and simultaneously and bilaterally transmits an optical telecommunications signal or signals at a wavelength other than the aforementioned energy wavelength. An optical amplifier 340 is serially coupled within the branch to accept the energy transmitted thereover and convert that energy into amplified telecommunications signals. Numerous modifications and alternative embodiments of the invention will be apparent to those skilled in the art in view of the foregoing description. Accordingly, this description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the best mode of carrying out the invention and is not intended to illustrate all possible forms thereof. It is also understood that the words used are words of description, rather than limitation, and that details of the structure may be varied substantially without departing from the spirit of the invention and the exclusive use of all modifications which come within the scope of the appended claim is reserved.

The specification relates to a repeaterless branch powered fiber optic communications system. The system comprises an optical fiber cable trunk, configured in ring topology, with one or more telecommunications hub, and one or more branching unit serially interconnected therein. Branching units are provided as convenient add/drop points along the trunk ring from which branch fiber optic cable radially extend to cable stations. Cable stations insert and extract telecommunications traffic from the trunk ring over the branch fiber optic cables. In addition, the branch fiber optic cables are also coupled to light emitting power sources. The branch fiber optic cables deliver the energy produced from these power sources to optical amplifiers serially embedded within the branch fiber optic cables, the branching units, or the optical fiber cable trunks. The optical amplifiers convert the energy delivered from the branch fiber optic cables into amplified telecommunications signals. Thus, remote pumping or energy delivery is achieved without the requirement of additional optical fiber cable runs and further, using solely passive repeaterless components.

big_patent

This is a continuation of application Ser. No. 08/182,910 filed on Jan. 14, 1994, now abandoned. BACKGROUND OF THE INVENTION 1. Field of the Invention The invention is directed to the field of installing wiring devices to ganged boxes mounted in building walls and more particularly to the provision of cover plate devices which can be used to cover such wiring devices to prevent unwanted access to such wiring devices and at the same time provide a finished look without exposed fasteners. 2. Description of the Prior Art At present when it is desired to install a wiring device such as a switch, a receptacle, a duplex receptacle, a combination receptacle and switch, etc., in a wall of a building, whether public, commercial or residential, it is necessary to cut a hole into such wall and install a ganged box adjacent the hole by attaching such box to a stud or the like. The ganged box is hollow to receive such wiring devices and provides pairs of mounting ears for mounting the wiring devices within and to the box. The size of the box is selected to accept all the wiring devices required at that location and the number of pairs, of mounting ears will be equal to the number of possible wiring devices which the box can receive. Once the wiring device is connected to the various conductors it will service, the wiring device is screwed to at least one pair of ears to mount the wiring device in and to the box. When all wiring devices are in place a cover plate having suitable apertures through it will be installed over the exposed wiring devices and the ganged box. The method of fastening the cover plate to the wiring devices is to use screws which pass through the cover plate and are received in threaded apertures in such wiring devices. The usual arrangement of mounting screws is one between each duplex receptacle and two, one to each side, for a switch. Thus, when a prior art wiring system containing two duplex receptacles and a switch was complete, one could see four exposed mounting screws. This made the completed job unsightly and could expose the user to a shock hazard if the correct insulation were not used during assembly. One prior art approach to hide these unsightly and potentially hazardous fasteners is shown in U.S. Pat. No. 4,873,396 issued Oct. 10, 1988 to Guity-Mehr. The cover plate was fashioned with an M-shaped groove near the bottom of the plate's back surface which could be positioned under the head of the lower fastening screw used to anchor the wiring device to the ganged box mounting ear. This mounting screw would have to be mounted so that the proper length of its body remained outside of the wiring device to be gripped by the M-shaped groove. If the screw was not sufficiently installed the cover plate would be free to rattle and if the screw was installed too deeply the M-shape groove could not be positioned under the screw head. Once the cover plate was positioned with the M-groove under the mounting screw, the cover plate is positioned so that the second mounting screw can be installed in a recessed groove in the front of the cover plate and screwed into the wiring device. Then a screw groove cover is fitted over the screw groove to hide the screw head and the screw groove. SUMMARY OF THE INVENTION The present invention overcomes difficulties noted above with respect to the devices of the prior art. The present invention provides a cover plate device that is quickly and easily installed using simple tools and available fasteners and which can be quickly and easily removed and can be fit upon walls that are not flat and even. This is accomplished by a two part device, the first an attachment member which is installed over a wiring device and mounted to such wiring device. The attachment member is symmetrical about its longitudinal and transverse axis so that there is no concern for its orientation. At its opposed, transverse ends, latching pawls are placed to each side of a central tab used to separate the cover plate member from the attachment member. The second part is a cover plate member which has no fastener holes extending through it and only has apertures to receive the wiring device projections as needed. A ridge extends about the periphery of the rear face of the cover plate member, and along the inside of its top transverse end it contains two saw-tooth shaped racks to receive in locking engagement the associated latching pawls of the attachment member. In the bottom transverse end, the two saw-tooth shaped racks flank a slot through which a small tool of appropriate shape can be inserted to contact the tab of the attachment member and employ it as a fulcrum to pry off the cover plate member latched to the attachment member. The use of multi-step racks allows each pawl to mate with its associated rack independently and thus accommodate variations in the flatness or evenness of the wall. This flatness or evenness is a greater problem as the cover plate member is increased in size to cover many wiring devices installed in ganged boxes. It is an object of this invention to provide an improved cover plate device for wall mounted electrical wiring devices. It is another object of this invention to provide an improved cover plate device for wall mounted electrical wiring devices having no visible fasteners when installed. It is yet another object of this invention to provide an improved cover plate device for wall mounted electrical wiring devices which is quickly and easily installed or removed. It is still another object of this invention to provide a two part device, one of which is installed using available fasteners and the second is installed to the first without visible fasteners. It is a further object of the invention to provide a cover plate device which can be properly positioned over wiring devices installed in a wall which is not flat or even. Other objects and features of the invention will be pointed out in the following description and claims and illustrated in the accompanying drawings which disclose, by way of example, the principles of the invention and the best modes which are presently contemplated for carrying them out. BRIEF DESCRIPTION OF THE DRAWINGS In the drawings in which similar elements are given similar reference characters. FIG. 1 is a front prospective view of the cover plate device installed over a wall mounted rocker switch in accordance with the instant invention. FIG. 2 is an exploded view of the device of FIG. 1. FIG. 3 is a front prospective, exploded view of the device of FIG. 1, showing the assembly of a first portion of the cover plate device over a wall mounted wiring device with the cover plate member separated to permit viewing of the assembly of the first portion with the wiring device. FIG. 4 is a side elevational view, in section, of the cover plate member of FIG. 3 taken along the lines 4--4. FIG. 5 is a side elevation, partially in section, of the cover plate member as shown in FIG. 4 installed upon the attachment member of the invention. FIG. 5a is a fragmentary, enlarged side elevation of the latching pawl of the attachment plate engaging the saw-tooth rack of the cover plate, both of which are shown in FIG. 5. FIG. 5b is a fragmentary, enlarged side elevation in section of the cover and tab of the attachment plate to indicate how the two components can be separated following latching. FIG. 6 is an exploded view of a cover plate device according to the invention to be used with two wiring devices. FIG. 7 is an exploded view of a cover plate device according to the invention to be used with three wiring devices. FIG. 8 is an exploded view of a cover plate device according to the invention to be used with four wiring devices. DESCRIPTION OF THE PREFERRED EMBODIMENTS Turning now to FIGS. 1 to 5, there is shown a cover plate device 10 constructed in accordance with the concepts of the invention. A suitable aperture 14 is cut into wall 12 to gain access to a ganged box mounted to a stud 15 or to permit installation of a suitable box to an adjacent stud or directly to the material of the wall (such as plasterboard). The ganged box 13 will be large enough to accept as many wiring devices as are needed. The ganged box 13 is made of metal or plastic and has one or more openings to permit the introduction of cable into the interior of the box 13, it has mounting means 19 to permit it to be anchored to an adjacent stud and pairs of mounting ears 21, each of which contains a threaded aperture 23 to which can be fastened the mounting screws of the wiring device such as, for example, rocker switch 18. In the normal order of things the wiring device is fastened to the box mounting ears 21 and the cover plate is then attached by screws to the wiring device, leaving at least one exposed mounting screw. The mounting screws have a small square of insulation about them to insulate the wiring device from the mounting ears 21 of ganged box 13. Absent such insulation the wiring device and the cover plate could become electrically hot if the ganged box comes into contact with a bare, hot conductor. The device of FIG. 1 clearly shows that when completely installed cover plate device 10 has no exposed mounting screws or other visible metal hardware. The only visible parts are the cover plate 16 and the rocker switch 18. As shown in FIG. 2, the rocker switch 18 has a body 20 which extends into the ganged box 13 and two lugs 22, one at each end of body 20, with threaded mounting holes 24 in each of such lugs 22. A mounting screw similar to screw 26 is passed through the unnumbered elongate mounting slots to mount switch 18 to the mounting ears 21 of the ganged box 13 as best seen in FIG. 3. With the instant invention an attachment plate 30 is attached to the switch 18 or other wiring device by the use of mounting screws 26. These pass through apertures 32 in the attachment plate 30 and engage the threaded apertures 24 in the lugs 22 of switch 18. Attachment plate 30 also contains a main aperture 34 of a shape complementary with the profile of the wiring device which extends through it. (See FIG. 3) The aperture 34 in FIG. 2 is rectangular to accept rocker switch 18. At each end 36 and 38, respectively, of attachment plate 30 are placed two latching pawls 40 and two latching pawls 42, respectively. As best seen in FIG. 5a, the pawl 42 has a vertical leg 44 which is an extension of attachment plate 30 but is much thinner and terminates in an angled leg 46 which extends at about a 45° angle with respect to the horizontal top edge of end 38 of attachment plate 30. Between each of the two latching pawls 40 and 42 is a tab 48 which will act as a tool pivot point for prying off the cover plate 16 when assembled to the attachment plate 30. As will be described below, a slot in the cover plate 16 lower edge provides access for the insertion of a small flat tool. The cover plate 16 is proportioned to fit over the entire attachment plate 30 as well as the ganged box into which a single wiring device, such as rocker switch 18, is placed and to which it is fastened. Thus, the cover plate 16 is slightly longer than the wiring device along the longitudinal axis but is between 30 and 40 percent wider along the transverse axis. The width varies depending upon how many boxes are ganged. The cover plate 16 has a front face 60 which is unbroken except for the central aperture 62 configured to the profile of the wiring device that extends through it and as shown in FIG. 2 is rectangular and a back face 64. Side walls 66 and 68 smoothly join the faces 60 and 64 to give a rounded upper edge to plate 16. The walls 66 and 68 flare out as they extend from plate 16 so that the bottom edge of walls 66 and 68 are further apart than where they join cover plate 16. End walls 70 and 72 also smoothly join faces 60 and 64 and further side walls 66 and 68 so that there are no sharp edges between the walls or between the walls and faces 60 and 64. Placed in the bottom end wall or ridge 72 is a slot 74 which provides access to the tab 48 as is best seen in FIG. 5b. A small, flat tool blade, such as screw driver blade 76, is moved through slot 74 in end wall 72 to contact both the outer surface of tab 48 and the back wall of slot 74. By moving the blade 76 in a counterclockwise direction using the back wall of slot 74 as a fulcrum the force applied to tab 48 will separate cover plate 16 from attachment plate 30. To attach cover plate 16 to attachment plate 30 the pawls 40, 42 on attachment plate 30 are made to engage the saw-tooth shaped racks 80 on the inner surfaces of end walls or ridges 70 and 72 of cover plate 16. There are two racks 80 on end wall or ridge 70 and two racks 80 on end wall or ridge 72. Each rack 80 contains a number of saw-tooth shaped teeth 82 each having an inclined front face 84 and a vertical back face 86. As best seen in FIG. 5a, as angled leg 46 engages the inclined front face 84 the pawl 42 is made to deflect in a counterclockwise direction sufficiently so that pawl 42 can get by the tip of the first tooth 82. Once leg 46 is past the tip of tooth 82, it can return to its initial position and take a position between the vertical back face 86 of the first tooth 82 and the inclined front face 84 of a second tooth 82. This operation can be repeated as many times as needed to get the bottom edges of the cover plate 16 as close to the mounting wall as possible. Since each of the racks 80 and pawls 40, 42 are independently operated it is possible to get the cover plate 16 to closely follow the mounting wall contour even if the wall is not flat, even, plane etc. This ability to follow the wall contour is even more appreciated where the cover plate 16 is large, such as with a cover plate to cover four ganged boxes. Once the angled leg 46 of the pawl 42 returns to its original position, any attempt to dislodge the cover plate 16 from the attachment plate 30 is opposed by the engagement of the vertical free edge of angled leg 46 with the vertical back face 86 of the tooth 82. However, since tool 76 can apply a great deal of force to tab 48 it is possible to separate plates 16 and 30. FIG. 6 shows a cover plate device for two wiring devices. The two wiring devices can be placed in a double ganged box 31 made up of two single ganged boxes 13 and joined by fasteners 25 extending through the threaded apertures 29 of two joining ears 27. The double ganged box 31 provides four mounting ears 21 each with a threaded aperture 23 to receive the mounting screws of the wiring devices (not shown). Additional ganged boxes 13 can be added to increase the overall ganged box arrangement as required. Attachment plate 130 has two apertures 134 which are of the same configuration. However, any combination of wiring devices could be employed so that one of the apertures could be a cut-out for a duplex receptacle, and another for a toggle switch, etc. There will be three racks 80 on the interior of each of the end walls 172 and 170 (not shown) and three pawls 140, on end wall 136 and three pawls 142 on end wall 138 of attachment plate 130. Also there will be two tabs 148 which will be accessible via slots 174 in end wall 172 of cover plate 116. The attachment plate 130 is attached the same way as attachment plate 30 and the installation is completed by installing cover plate 116. Because of the independent operation of the pawls 140, 142 with their respective racks 80, the cover plate 116 will be able to compensate somewhat for irregularities in the wall in which the wiring devices are installed. It appears that for any cover plate device which is to fit over an even number of ganged boxes or an even number of wiring devices there will be an odd number of racks 80 and an odd number of pawls 40,42,140, 142 and an even number of slots 74, 174 and an even number of tabs 48, 148. FIG. 8 shows an arrangement to cover the installation of four ganged boxes and the four wiring devices they could mount. According to the observations made above, for an even number of wiring devices to be installed with the proper attachment plate 330 and cover plate 316, there will be four cut-outs or apertures 334 in attachment plate 330 and four cut-outs or apertures 362 in cover plate 316; five pawls 340 on end wall 336 and five pawls 342 on end wall 338 which each cooperate with an associated one of the ten racks 80 of cover plate 316, some of which are shown on the inside surface of the end walls such as 372. There will also be four tabs 340 which each can be reached through one of the slots 374 adjacent the associated tab 340. In FIG. 7 there is shown an arrangement to cover three wiring devices mounted in three ganged boxes (not shown) with an attachment plate 230 and cover plate 216 each of which have three apertures 234 and 262, respectively. There are four pawls 240 on end wall 236 and four pawls 242 on end wall 238. The pawls 240 and 242 will engage an associated rack 80 some of which are shown on the inside surface of the end wall 272 and the opposite end wall 270 (not shown). The three tabs 248 which are placed adjacent the slots 274 in wall 272 can be reached through those slots. The order of installation of the device of FIG. 7 is substantially the same as already set forth. Attachment plate 230 is attached to the ears of the ganged boxes (not shown) using screws 226 after which the cover plate 216 is aligned and placed over the attachment plate 230 and locked thereto by the engagement of the pawls 240 and 242 with associated racks 80. It should be evident now that where there is an odd number of cut-outs or apertures in the attachment plate and cover plate there will be an even number of pawls 40, 42, 240, 242, an even number of racks 80, and an odd number of tabs 48, 248 and slots 74, 274. While there have been shown and described and pointed out the fundamental novel features of the invention as applied to the preferred embodiments, it will be understood that various omissions and substitutions and changes of the form and details of the devices illustrated and in their operation may be made by those skilled in the art without departing from the spirit of the invention.

A cover plate device for covering a wall mounted wiring device having no visible fasteners when installed. An attachment plate is attached over and to a wiring device which has been mounted in and to a ganged box mounted adjacent an aperture in a wall. Latch pawls are arranged at the opposite longitudinal ends of the attachment plate. A cover plate member overlies the wiring device and ganged box and provides a series of recesses to receive the associated pawls in locking arrangement. Because of the number of recesses available at each pawl location, the cover plate can still be installed even if the wall is not flat or even. The attachment plate and cover plate member can be provided with various types and numbers of apertures, and the number of pawls and groups of recesses employed depend on the size of the attachment and cover plate members.

big_patent

FIELD OF THE INVENTION The present invention relates to a collapsible light-shielding device for a screen. With this invention, a wide range of applications is intended, such as television sets, monitors, etc. BACKGROUND OF THE INVENTION A known shielding device of this kind is disclosed in U.S. Pat. No. 4,444,465 and consists of an undeformable U-shaped shaft section of flanged plastic plate material. The shaft section is placed upside down over the housing of the screen, i.e. with the legs of the shaft section pointing downwards. Thus, the body of the shaft section rests on the upper side of the housing, while its legs are on either side of the screen. In the extended position, the shaft section projects from the housing beyond the displaying screen and prevents irritating reflections of natural light and/or artificial light on the glass of the screen, thereby rendering the image shown on the displaying screen clearer. The known shielding device is collapsible by pushing it over the housing into a position in which the shielding device does not project beyond the screen. This known shielding device has several disadvantages. In order to ensure that the shielding device remains balanced in its operating position, a special fastening device is required which consists of a bracket which has to be attached on top of the housing. As a result thereof, a relatively expensive part is required which greatly affects the outward appearance of the housing. Furthermore, the shielding device is bulky under any circumstance, which can be irritating and may also adversely affect the outward appearance of the housing of the screen. In addition, the user is required to sit straight in front of the displaying screen when the shielding device is extended, as the shielding device is too much of a nuisance when viewing the displaying screen at an angle. SUMMARY OF THE INVENTION The object of the invention is to provide an improved extendable shielding device. For this purpose, the light-shielding device according to the invention is characterized by a number of annular strips concentrically nested and essentially enclosing one another in a tight manner, which strips are suitable to be fixed in front of a displaying screen and in that case surround the screen, said strips furthermore being suitable to slide over one another between a pushed-in position, in which they essentially cover one another, and a pushed-out position, in which they are essentially uncovered. Thus, it is possible to fold the light-shielding device around the displaying screen so that it is of very small size. In the folded-in state, the shielding device takes up relatively little space and therefore does not form an obstruction. Furthermore, the light-shielding device according to the invention can easily be fitted to a screen, for example using Velcro. Especially when the strips of the light-shielding device have a decreasing wall thickness, viewed in the axial direction, it is also possible to place the light-shielding device in various positions relative to the face of the screen, so that the displaying screen can be viewed from different angles without hindrance. Preferably, the strips of the light-shielding device are provided with hook elements or locking elements to ensure reliable folding-in and folding-out of the light-shielding device. Furthermore, the invention provides an adapter member providing a flat attachment face for the light-shielding device. Thus, by using the adapter member, the light-shielding device, which usually requires a flat attachment face, can be fixed to virtually any type of monitor, with either a flat or a single- or or double-curved front. The strips can be of solid design, for example produced by injection-moulding, but may also be produced by bending plate material, preferably provided with integrated hook or locking elements. Thus, the present invention provides a collapsible light-shielding device for a screen, which consists of as few parts as possible, is inexpensive to produce, operates reliably and can easily be fitted to a monitor. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be explained in more detail below with reference to an exemplary embodiment which is shown in the attached drawings and does not limit the invention. In these drawings: FIG. 1 shows a perspective view of the collapsible light-shielding device according to the present invention, mounted on a monitor which is only shown in part here; FIG. 2 shows a sectional view of a part of the collapsible light-shielding device of FIG. 1, with the light-shielding device in a partly folded-in position and mounted on a monitor which is only shown in part; FIG. 3 shows a view according to FIG. 1 of part of the collapsible light-shielding device shown in a different position and without the monitor; FIG. 4 shows the profile section of an individual solid strip of the light-shielding device according to the present invention; FIG. 5 shows a view according to FIG. 4 of a modification of the strip; and FIG. 6 shows a view according to FIG. 4 of another modification of the strip. DETAILED DESCRIPTION OF THE INVENTION FIG. 1 shows a monitor 1 having a displaying screen 2 around which a light-shielding device 3 according to the present invention has been fitted. As will become more apparent below, said light-shielding device 3 has a flange 4 by means of which it is attached to the monitor 1, as well as a number of, preferably 10, plate-shaped annular strips 5 which are concentrically nested with little play. As illustrated in FIG. 1, the light-shielding device as shown in the drawing is extended less far at the front than at the back, thereby enabling the displaying screen 2 to be viewed at a relatively acute angle. Other positions of the light-shielding device can also be effected, for example a downward or upward angle, if desired in combination with a sideways angle. Of the light-shielding device 3, FIG. 2 only shows the innermost strip 5' connected with the monitor 1 and two further strips 5 directly adjacent thereto. At the end facing the monitor 1, the strip 5' has a flange 4 protruding at right angles, and at the other end a hook 6. The further strips 5 have a hook 6 on the one end and a hook 7 at the other end, which hook 7 protrudes from the opposite side. It can clearly be seen that the hook 7 of the further strip 5 interacts with the hook 6 of the strip 5', thereby preventing the further strip 5 from being extended further over the strip 5' in the direction of the arrow a, and the light-shielding device 3 from separating into its component parts. In addition, each further strip 5, of which only two are shown here but of which there are usually nine, has a locking projection 8 at the end near the hook 7, on the side of the hook 6. As can be seen in FIG. 2, such a projection 8 of one further strip 5 interacts with the hook 7 of the other further strip 5, when these further strips 5 are pushed over one another counter to the direction of the arrow a. It is thereby ensured that the other further strips 5 are likewise pushed in, ultimately over the fixed strip 5', when the outermost further strip 5 is being pushed counter to the direction of the arrow a. Furthermore, FIG. 2 shows how the flange 4 is connected to the monitor 1 with the interposition of an adapter member 9 likewise shown in cross section. The adapter member 9 is essentially plate-shaped and runs in a concentrically annular manner around the displaying screen 2, as do the strip 5' and the further strips 5. On the side facing away from the flange 4, the adapter member 9 has recess 10 which is filled with a felt-like or sponge-like material which can be compressed to a large extent. As can be seen, the recess 10 extends from the radial inner edge of the adapter member. On the radial outer edge, also on the side facing away from the flange 4, the adapter member 9 has an axial projection 11 which grips around the monitor 1. As the adapter member 9 is made of readily elastically deformable material, the projection 11 serves as a kind of apron by means of which the adapter member 9 can be attached to the monitor 1 in an attractive manner, without too large a gap being formed. A convex shape of the front of the monitor can be compensated for by the space 10, which is filled with highly compressible material and by means of which the adapter member 9 provides a flat attachment face for the flange 4. The recess 10 may, for example, not be present on any of the four corners of the adapter member, so that there the adapter member 9 bears against the monitor 1 with its entire surface. Furthermore, FIG. 3 shows part of the light-shielding device of FIGS. 1 and 2 in a different extended position. It can clearly be seen how the hooks 6 and 7 on the strips 5 and 5' interact. In this case as well, only the fixed strip 5' and the next three further strips 5 have been shown for the sake of clarity. FIG. 4 shows the profile section of the strips 5. The total length is 16 mm. On the side of the hook 6, the thickness t 1 is 1.1 mm; on the side of the hook 7, the thickness t 2 is 0.6 mm. The total height of the profile section on the side of the hook 6 is 2.1 mm; on the side of the hook 7, the total height is 3.1 mm. Thus, the thickness of every strip 5, 5' decreases in the axial direction, the thickness on the side of the hook 6 being greater than that on the side of the hook 7. This means that when a strip 5 is completely extended relative to the adjacent strip 5, the strips 5 enclose one another more tightly compared to the position where the adjacent strips are pushed over one another as far as possible. Thus, on the one hand, a good positive locking is provided for the strips in the position as shown, for example, in FIG. 3, and, on the other hand, sufficient play is provided in positions which are not fully extended in order to effect a slanting position, for example according to FIG. 1. Furthermore, FIG. 5 shows a modification of the profile section shown in FIG. 4. In this case, the modification shown in FIG. 5 is a bent profile section made from plate material with integrated hooks 6 and 7 and projection 8. Using a plate thickness of 0.3 mm, the decrease in thickness can be effected in a way similar to that of the embodiment of FIG. 4. FIG. 6 shows another modification to the profile section of the strips 5. The total length is 21.25 mm. At the indicated position, the thickness t 1 is 1.1 mm; on the side of the hook 7, the thickness t 2 is 1.9 mm. The total height of the profile section on the side of the hook 6 (t 4 ) is 1.9 mm; on the side of the hook 7 (t 3 ), the total height is 4.1 mm. At hook 7, before the inclined part C, the thickness of the strip is constant. As indicated, the lower face 20 is substantially flat; merely the outer part at hook 6 is somewhat lowered. The upper face 21 is inclined. The greatest inclination is indicated at arrow C. However, at arow A, the inclination still is 2°, while at arrow B the inclination is 5°30'. Thus, the thickness in the axial direction, the thickness on the side of the hook 7 being greater than that on the side of the hook 6. Apart from the advantages as with the strips of FIGS. 4 and 5, the strip according to FIG. 6 provides improved positioning of the strips with respect to each other since the provision of the part at constant thickness. Of course, it is possible to conceive modifications of the embodiments described and shown here. The essence of the invention is that the light-shielding device consists of annular strips which are concentrically nested and essentially enclose one another in a tight manner, which strips preferably have a decreasing wall thickness, viewed in the axial direction, so that the light-shielding device can be set to various angular positions relative to the screen, making it possible to view the displaying screen from various angles. The invention is therefore defined in more detail by the appended claims.

Collapsible light-shielding device (3) for a displaying screen (2), having a number of annular strips (5', 5) concentrically nested and essentially enclosing one another in a tight manner, which strips are suitable to be fixed in front of a displaying screen and in that case surround the screen. Furthermore, the strips are adapted to slide over one another between a pushed-in position, in which they essentially cover one another, and a pushed-out position, in which they are essentially uncovered. Preferably, the strips (5, 5') have a decreasing wall thickness, viewed in the axial direction.

big_patent

BACKGROUND [0001] 1. Field of the Invention [0002] the present invention relates to automated speech technologies and, more particularly, to automatically providing an indication to a speaker when that speaker's rate of speech is likely to be greater than a rate that a listener is able to comprehend [0003] 2. Description of the Related Art [0004] Understanding a person speaking their native language can be difficult when that language is not a primary language of a listener since the native speaker often speaks too rapidly for the listener to digest the spoken words. For example, a person from Japan, who is moderately proficient in English, can have trouble understanding a native English speaking person, who is speaking at a pace that would be typically used when talking to another native English speaker. [0005] One simple solution to improve understanding is for a speaker to slow down their speaking rate when speaking to a non-native speaker. Unfortunately, a speaker often fails to recognize the listener's difficulty in understanding a conversation and fails to decrease their speaking rate. The non-native listener is often embarrassed or reticent to ask the speaker to slow down. This can be especially true if the listener has already asked the speaker to slow down once or twice during a conversation, which the speaker has done only to inadvertently increase his or her speaking rate as the conversation endures or as the emotional pitch of the conversation escalates. [0006] Acoustic an semantic clarity of a speaker is also a factor for determining a speaking rate, which a listener can comprehend. For example, when a speaker uses colloquialisms, which can be very difficult for a non-native speaker to process, a speaking rate should be even slower than normal. In another example, strong accents and/or dialects can increase listener difficulty, even when a listener is a native speaker of the language being spoken. This increased listener difficulty can be compensated for by a corresponding speaking rate decrease. Additionally, when a speaker mumbles or has speech idiosyncrasies, he or she can be harder than normal to understand, unless the speaking ate of the speaker is decreased to a slower than normal rate. In still another example, a clarity problem can occur for communications over a voice network connection due to the quality of the voice network being low or inconsistent. As a result, the speech received by a listener can be difficult to comprehend. Network clarity problems can be compensated for by having a speaker decrease their rate of speech. No known device or solution exists that detects situations in which a speaking rate is too rapid for a listener and that automatically informs a speaker to reduce his or her speaking rate accordingly. SUMMARY OF THE INVENTION [0007] The present invention discloses a solution that automatically informs a speaker to decrease his or her speaking rate, when that rate likely exceeds a rate that a listener can understand. This can be accomplished by determining a speaking rate for the speaker, which is compared against a speaking rate threshold. The speaking rate threshold can be based upon a listening rate, estimated or known, of the listener. The listening rate can be a variable value based in part upon a proficiency that the listener has with a language being spoken. The speaker can be informed to slow down by an activation of a sensory mechanism of a wearable computing device that is designed to vibrate, beep, blink, speak a message, display a message, and the like, whenever a speaking rate of the speaker exceeds the speaking rate threshold. [0008] The present invention can be implemented in accordance with numerous aspects consistent with the material presented herein. For example, one aspect of the present invention can include an automated method to facilitate understanding between discourse participants. The method can include a step of automatically ascertaining a speaking rate threshold for a listener. The speaking rate threshold can be a threshold over which the listener is likely to have difficulty comprehending speech. A speaking rate of a speaker can then be automatically determined. The speaker can be automatically notified that his or her speaking rate should be decreased, whenever the speaking rate exceeds the speaking rate threshold. [0009] Another aspect of the present invention can include a method for facilitating comprehension during a discourse bed in part upon a discourse language. The method can begin in a situation wherein a speaker is engaged in a discourse with a listener. A language of the discourse can be determined. A listener's proficiency with the language can be ascertained and used to establish a speaking rate threshold. A speaking rate of the speaker can then be determined. When the speaking rate exceeds the speaking rate threshold, the speaker can be automatically notified to decrease his or her speaking rate. [0010] Yet another aspect of the present invention can include a device for facilitating understanding between discourse participants that includes a microphone and a sensory mechanism. The microphone can receive speech of a speaker. The sensory mechanism can automatically inform the speaker when tat speaker's rate of speech is too rapid for a listener to easily comprehend spoken dialog. The determination that the speaking rate is too rapid can be based upon automatically comparing the speaking rate of the speaker against a previously established speaking rate threshold. [0011] In one embodiment, the device can also include a speaking rate processor and a comprehension comparator. The speaking rate processor can determine the speaking rate for speech, which is obtained via the microphone. The comprehension comparator can compare the determined speaking rate against the speaking rate threshold. In a different embodiment, the device can include a transceiver that communicatively connects the device to a network element, which performs the functions ascribed to the speaking rate processor and the comprehension comparator. [0012] It should be noted that various aspects of the invention can be implemented as a program for controlling computing equipment to implement the functions described herein, or a program for enabling computing equipment to perform processes corresponding to the steps disclosed herein. This program may be provided by sorting the program in a magnetic disk, an optical disk, a semiconductor memory, or any other recording medium. The program can also be provided as a digitally encoded signal conveyed via a carrier wave. The described program can be a single program or can be implemented as multiple subprograms, each of which interact within a single computing device or interact in a distributed fashion across a network space. [0013] The method detailed herein can also be a method performed at least in part by a service agent and/or a machine manipulated by a service agent in response to a service request. BRIEF DESCRIPTION OF THE DRAWINGS [0014] There are shown in the drawings, embodiments which are presently preferred, it being understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. [0015] FIG. 1 is a schematic diagram showing a solution for increasing comprehension by detecting a speaker's rate of speech, comparing the speaking rate to a listening rate, and warning the speaker to slow down when the speaking rate exceeds the listening rate. [0016] FIG. 2 is a flow chart of a method for automatically notifying a speaker to decrease their speaking rate in accordance with an embodiment of the inventive arrangements disclosed herein. DETAILED DESCRIPTION OF THE INVENTION [0017] FIG. 1 is a schematic diagram showing a solution for increasing comprehension by detecting a speaker's rate of speech, comparing the speaking rate to a listening rate, and warning the speaker to slow down when the speaking rate exceeds the listening rate. System 100 shows a speaker 102 engaged in a discourse 108 with one or more listeners 110 . A device 130 can monitor the rate of speech during the discourse 108 . When the rate of speech is too rapid for listener 110 comprehension, an indicator 106 warning the speaker 102 to slow down can be provided. [0018] In one embodiment, the discourse 108 can be in a language other than a primary language of listener 110 . The listener 110 may be able to comprehend the spoken language, but not at a rate which a native speaker could understand it. A number of techniques can be used to automatically determine that a current language is not a primary language of the listener 110 . [0019] Further, various ones of the techniques may detect that an alternative language to that the discourse 108 language exists, which both the speaker 102 and the listener 110 are proficient in. When this is the case, the indicator 106 can include an option to shift the discourse 108 to the alternative language. [0020] The discourse 108 can include any conversation involving the speaker 102 and the listener 110 . The discourse 108 can include a face-to-face conversation, a telephone conversation, a Web-based interaction having a voice modality, a speaking engagement involving a group of attendees (listeners 110 ) and the speaker 102 , and other communications. [0021] In situations where a voice communication occurs using telephony devices that are linked via a network, a quality of the voice network connection can also be an important factor in determining a listener's 110 ability to comprehend the discourse 108 . To account for network clarity, the device 130 can monitor a quality of a voice connection during a call and can prompt 106 the speaker 102 to decrease his or her speaking rate to a rate more comprehensible to listener 110 , considering an overall quality, nature, and language of received speech. [0022] The device 130 can be a wearable device, such as a smart phone, which can vibrate, blink, produce speech, and/or provide another indicator 106 that notifies speaker 102 to decease a speaking rate or to adjust a speaking language. In such an embodiment, the device 130 can be operable during mobile telephony calls where the listener 110 is a call participant as well as when no calls are being made where the listener 110 is a bystander. Thus, device 130 can add an entirely new function to a mobile telephone or other portable device, which is able to leverage computing capabilities of the portable device to provide this new speaking rate detection and notification ability. [0023] The device 130 can also be integrated into a teleprompter or other mechanism or set of mechanisms that are present in an environment in which speeches are routinely given. Additionally, the device 130 can be a portable device worn by the listener 110 that includes a sensory mechanism noticeable by the speaker 102 , which is selectively activated to notify the speaker 102 that a current rat of speech is too rapid for the listener 110 . The device 130 can be implemented as a stand-alone computing device, as a networked computing device that utilizes processing capabilities of a remotely located networked device 150 , and/or as a series of communicatively linked distributed mechanisms that together cooperatively perform the operations disclosed herein. [0024] As shown in system 120 , the computing device 130 can include a microphone 132 , a sensory mechanism 133 , a speaking rate processor 134 , a language detector 135 , a speech clarity processor 136 , a comprehension comparator 137 , a wireless transceiver 138 , and the like. The microphone 132 can be any device that converts acoustic sound waves into an electrical representation. Microphone 132 can be used to capture the speech of speaker 102 and listener 110 to determine a language being spoken, a speaking rate, and/or a language proficiency level. [0025] Sensory mechanism 133 can be any mechanism for informing speaker 102 that his/her speaking rate should be decreased. For example, a vibration, a tone, a flashing LED, a displayed message, a speech message, a haptic or tactile indicator, and the like can be indications provided by mechanism 133 . In an embodiment having multiple sensory mechanisms 133 available, an active mechanism can be user configurable. [0026] The speaking rate processor 134 can be used to process speech of the speaker 102 and to dynamically determine a speaking rate. The language detector 135 can process speech to determine a language being spoken. The comprehension comparator 137 can compare a speaking rate against a speaking rate threshold and can trigger mechanisms 133 to indicate a speaker 102 needs to slow down, when appropriate. [0027] The speech clarity processor 136 can analyze speech to determine a clarity value, which can be used to adjust a speaking rate and/or a speaking rate threshold. The clarity value can be based upon a clarity with which a communicating party 102 speaks and also based on a quality of a voice network connection, if any is present, over which speech is conveyed to a listener 110 . [0028] In one contemplated implementation, a speaker table 164 can be constructed and stored in a memory accessible by device 130 . The speaking table 164 can enumerate languages spoken by a speaker 102 and can relate a clarity value to each spoken language. The information about speaker languages contained in table 164 can be useful in embodiments that suggest an alternative language, such as Spanish, as shown in indicator 106 , which is shared by both the speaker 102 and the listener 110 . [0029] Wireless transceiver 138 can be used to exchange digital content between device 130 and one or more eternal systems communicatively linked to the network 145 . For example, wireless transceiver 138 can be used to exchange digital content between computing device 130 and network device 150 . Network device 150 can include speech processing components 152 configured to perform one or more of the operations associated with processor 134 , detector 135 , processor 136 , and/or comparator 137 . Remote speech processing by components 152 can be particularly advantageous in situations where device 130 is a resource constrained device that is unable to locally perform speech processing operations. [0030] Device 150 can also include one or more listener profiling and/or identification components 154 . In one embodiment, the listener profiling components 154 can cooperatively interact with listener identifying mechanisms 140 . For example, mechanism 140 can be a Radio Frequency Identification (RFID) tag worn by a listener, which is readable by components 154 . The tag can provide a listener identification that can be a key value of listener table 162 , which can relate to listener languages and listening rates. The listening rates can correspond to a language proficiency and can be used to establish a listener-specific speaking rate threshold. Listening rate thresholds and additional information can also be directly stored upon the RFID tag, worn by the listener 110 . [0031] In another embodiment, the listener profiling components 154 can use speech analysis, video analysis, and other technologies to identify the listener 110 , so that table 162 values can be utilized. In yet another embodiment, the listener profiling components 154 can be configured to determine characteristics of a listener 110 , as opposed to actual listener identity, which are indicative of a language proficiency. For example, components 154 can determine a speaking rate of the listener in the discourse 108 language and can base the speaking rate threshold on the listener's speaking rate. In another example, listener speech can be examined for semantic and acoustic queues that are indicative of the listener's proficiency with a particular language. In still another example, a listener's appearance can be analyzed for region specific characteristics, such as Asian characteristics, Arabic characteristics, and the like, and assumptions relating to language proficiency can be made based upon these characteristics. Preferably, imprecise indicators, such as appearance based markers, can be combined with other indicators to increase an accuracy of language proficiency estimations. [0032] As shown in system 120 , network 145 can include any hardware/software/and firmware necessary to convey digital content encoded within carrier waves. Content can be contained within analog or digital signals and conveyed through data or voice channels. The network 145 can include local components and data pathways necessary for communications to be exchanged among computing device components and between integrated device components and peripheral devices. The network 145 can also include network equipment, such as routers, data lines, hubs, and intermediary servers which together form a packet-based network, such as the Internet or an intranet. The network 145 can further include circuit-based communication components and mobile communication components, such as telephony switches, modems, cellular communication towers, and the like. The network 145 can include line based and/or wireless communication pathways. [0033] Additionally, data store 160 can be a physical or virtual storage space configured to store digital content. Data store 160 can be physically implemented within any type of hardware including, but not limited to, a magnetic disk, an optical disk, a semiconductor memory, a digitally encoded plastic memory, a holographic memory, or any other recording medium. Further, data store 160 can be a stand-alone storage unit as well as a storage unit formed from a plurality of physical devices. Additionally, content can be stored within data store 160 in a variety of manners. For example, content can be stored within a relational database structure or can be stored within one or more files of a file storage system, where each file may or may not be indexed for information searching purposes. Further, data store 160 can optionally utilize one or more encryption mechanisms to protect stored content from unauthorized access. [0034] FIG. 2 is a flow chart of a method 200 for automatically notifying a speaker to decrease their speaking rate in accordance with an embodiment of the inventive arrangements disclosed herein. The method 200 can be performed in the context of system 120 . [0035] Method 200 can begin in step 205 , where a discourse involving a speaker and one or more listeners can be identified. In step 210 , a language being spoken can be detected. In step 215 , a determination can be made regarding whether the spoken language is a primary language of the listener. If so, the method can progress from step 215 to step 220 , where a speaking threshold can be set to that of a native speaker. The method can then skip from step 220 to step 250 . [0036] When the spoken language is not a primary language of the listener, the method can progress from step 215 to step 225 , where an attempt can be made to determine the listener's identity. If the attempt of step 225 is successful, step 230 can be performed, where a listening rate associated with the listener can be determined. In step 235 , a speaking rate threshold can be set to the listener specific rate. The method can skip from step 235 to step 250 . [0037] When in step 225 , a listener identify cannot be determined, the method can progress to step 240 , where the listener can be profiled to estimate a listening rate. For example, speech processing of listener provided speech can be performed to detect whether the listener has a heavy accent, which can be indicative of the listener not being a native speaker of that language. In step 245 , the speaking rate threshold can be set to the estimated listening rate. [0038] In step 250 , a speaking rate for the speaker can be determined. In optional step 255 , a speaking clarity value can be determined for the speaker. The speaker rate can be adjusted in accordance with the speaking clarity. That is, a faster speaking rate can be comprehensible when speech clarity is high than when speech clarity is low. In one contemplated embodiment, speaking clarity can be affected by the emotional content or emotional pitch of a discourse. Thus, one actor in determining a clarity value can be ascertained by analyzing the discourse for emotional content. Generally, discourses with high emotional content have a lower clarity level than discourses with minimal emotional content. [0039] In step 260 , a determination can be made as to whether the speaking rate is less than or equal to the speaking threshold. This comparison can indicate whether the listener is able to comprehend the conversation. When the speaking rate does not exceed the threshold, the method can loop from step 260 back to step 250 , where a speaking rate for the speaker can again be determined. The loop can continue for a duration of a discourse. [0040] When the speaking rate exceeds the speaking threshold, the method can progress from step 260 to step 265 , where the speaker can be notified to reduce their speaking rate. In optional step 270 , a determination can be made as to whether the speaker and listener share a language other than the language being spoken. For example, the speaker, who was originally speaking in English, can also speak Spanish, which can be a primary language of the listener. Moreover, the speaker's proficiency with Spanish can be greater than the listener's proficiency with English, which would make changing the language of the discourse beneficial from an overall comprehension standpoint. In step 275 , the speaker can be notified of the shared alternative language, and be thereby provided an option to shift the conversation language to the alternative language. When a language change occurs, different values for the speaking rate threshold and speaker clarity can be determined (not shown). The method can loop from step 275 to step 250 , where a speaking rate of the speaker can continue to be determined. [0041] The present invention may be realized in hardware, software, or a combination of hardware and software. The present invention may be realized in a centralized fashion in one computer system or in a distributed fashion where different elements are spread across several interconnected computer systems. Any kind of computer system or other apparatus adapted for carrying out the methods described herein is suited. A typical combination of hardware and software may be a general purpose computer system with a computer program that, when being loaded and executed, controls the compute system such that it carries out the methods described herein. [0042] The present invention also may be embedded in a computer program product, which comprises all the features enabling the implementation of the methods described herein, and which when loaded in a computer system is able to carry out these methods. Computer program in the present context means any expression, in any language, code or notation, of a set of instructions intended to cause a system having an information processing capability to perform a particular function either directly or after either or both of the following: a) conversion to another language, code or notation; b) reproduction in a different material form. [0043] This invention may be embodied in other forms without departing from the spirit or essential attributes thereof. Accordingly, reference should be made to the following claims, rather than to the foregoing specification, as indicating the scope of the invention.

The present invention discloses a solution that automatically informs a speaker to decrease his or her speaking rate, when that rate likely exceeds a rate that a listener can understand. This can be accomplished by determining a speaking rate for the speaker, which is compared against a speaking rate threshold. The speaking rate threshold can be based upon a listening rate, estimated or known, of the listener. The listening rate can be a variable value based in part upon a proficiency that the listener has with a language being spoken. The speaker can be informed to slow down by an activation of a sensory mechanism of a wearable computing device designed to vibrate, beep, blink, speak a message, display a message, and the like, whenever a speaking rate of the speaker exceeds the speaking rate threshold.

big_patent

BACKGROUND OF THE INVENTION The invention relates to a device for the optical recording of rapid processes with a TV camera, which comprises means for deviating and suppressing the beam, in order to make the scanning beam run successively and cyclically over N lines of a picture plane on which the processes are optically projected. For control and/or analysis purposes, laboratory and industrial processes often require the optical recording of rapidly changing phenomena. The picture sequence of conventional TV cameras of the European standard is 25 Hz, so that the recording of a TV picture requires 40 ms, or 20 ms for a half-frame. Higher picture frequencies can be obtained with high speed cameras, the price of which, however, is significantly higher than that of TV systems. Furthermore, such a camera is based on the principle of photochemical (film) recording, so that an immediate interpretation, for example a computer-assisted interpretation of the pictures, is not possible. Special TV systems with increased resolution for professional use have already been developed, in which the number of lines and the speed of line scanning are doubled with respect to the European TV standard, while a half-frame is still scanned in 20 ms. Finally, a TV system is conceivable in which the geometrical resolution, i.e. the number of lines is not increased, but only the scanning speed of one line is increased, so that with a constant or even reduced number of lines, a higher picture sequence frequency can be obtained. This would, however, necessitate an expensive new concept of the whole TV system. Contrary hereto, it is the aim of the invention to provide a device as mentioned above, which permits, with simple means and even in a very flexible way, TV recordings of rapid processes with a high and selectable resolution in time. SUMMARY OF THE INVENTION It is, therefore, an object of the present invention to provide a device for the optical recording of rapid processes with a TV camera, to obtain a higher picture sequence frequency. The device comprises means for deviating and suppressing the beam in order to make the scanning beam run successively and cyclically over N lines of a picture plane on which the processes are projected; a cyclic line counter, which carries out one counting step for each line pulse and which supplies an end-of-count pulse after p line pulses respectively, N/p being an integer >>1, the end-of-count pulse being applied to the beam suppression circuit of the TV camera for picture beam suppression; and a sawtooth generator synchronized with the output pulses of the counter and to control the vertical deviation of the beam. Preferably, the sawtooth generator and the beam suppression circuit are controlled via a delay device, the delay time of which constitutes a selectable part of a line period and which is triggered by the output of the counter. In a preferred embodiment, the line counter is a programmable counter. BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described in more detail by means of a preferred embodiment with reference to the drawings. FIG. 1 shows a block diagram of a device according to the invention, and FIG. 2 shows some characteristic pulse shapes which occur during the operation of the device according to FIG. 1. FIG. 3 shows the path of the cathode beam over the picture plane of the camera for p =8. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 shows a TV recording tube 1, which comprises in the usual way a cathode beam unit 2 for creating a scanning beam and beam deviating means 3, 4 for the horizontal deviation as well as for the vertical deviation of the beam, respectively. The beam originating from the cathode beam unit 2 can be moved systematically over a picture plane 5, on which the rapid processes to be recorded are optically projected and in which, during scanning, a high electrical signal is produced as a function of the brightness value of a scanned point. This electrical signal is conveyed to a pre-amplifier 6. The signal from pre-amplifier 6 is mixed in a known way in a video amplifier 7 with standardized synchronization and level definition pulses for the black level and the white level and is then delivered as a video signal to an output 8. An oscillator 9 oscillating at 15.625 kHz controls the deviation means 3 and 4. A pulse former 10 following the oscillator supplies narrow pulses of said frequency to a sawtooth generator 11, which is connected to the horizontal deviation means 3. In a common TV camera, the pulse former 10 is followed by a divider by N=312, whose output is applied to a sawtooth generator 12 for controlling the vertical deviation means 4. Further, in a usual TV camera, there is a beam suppression circuit 13, which is synchronized with the sawtooth pulses supplied by the generators 11 and 12 and is used in the deviation means 3 and 4, to provide beam suppression pulses of appropriate width for suppressing the beam during the line (Z) and the picture change periods (B), respectively. According to the invention, as shown in FIG. 1, this usual circuitry of a TV camera is only slightly modified, i.e. as concerns the vertical deviations and the beam suppression for the picture change synchronized therewith. The control pulses for the vertical deviation are not derived from the output pulses of the pulse former 10 via a fixed divider through N (312), but rather a cyclic counter 14 is supplied with the output pulses from the pulse former 10 with a sequence frequency of 15.625 kHz. Counter 14 counts these pulses from pulse former 10. The counting capacity of this counter, i.e. the number of count steps p, which this counter needs to reach its initial state, is only a fraction of the value N (312) generally used in common TV cameras. In particular, p is chosen such that the ratio of line number N to p is an integer significantly greater than 1. In a preferred embodiment, the counter 14 is a programmable counter, whose value p can be regulated at a control desk. Therefore, at an output 15 of this counter, a narrow pulse appears after the scanning of p lines. This pulse is used via a delay means 16 to control the sawtooth generator 12 as well as to control both the vertical deviation means 4 and the beam suppression circuit 13 provided for the cathode beam unit 2. By means of switches (not shown), the slope of a sawtooth 12 is adapted to the shortened picture cycle. These switches can be regulated manually or automatically together with the counter 14, so that each value of p corresponds to a defined slope. The device shown in FIG. 1 is further explained with respect to the pulse diagrams of FIG. 2. For the sake of simplicity, the number p has been chosen to be eight, which is very small. In the first diagram of the FIG. 2, a series of line pulses 20 are shown which are supplied by the pulse former 10. The counter 14 has a counting capacity of 8 counting steps. Each time it reaches the counting end, it supplies a pulse at the output 15, which is delayed in the delay means 16 to such an extent, that the beam suppression for the picture change B 22 and the control of the sawtooth generator 12 for the vertical deviation can take place at the right moment. These signals are represented in FIG. 2 in the second (22) and third (24) lines, respectively. If the beam suppression periods are disregarded, eight lines of the picture projected on the picture plane 5 are scanned. The scanning scheme which shows the path of the cathode is indicated in FIG. 3. As the scanning of a line takes approximately 64 microseconds, about 0.5 milliseconds are needed for the recording of the whole picture consisting of 8 lines, which results in a picture repeat frequency of approximate 2000 sec -1 . Due to the limitation to 8 lines by means of only slight modifications in a conventional TV camera, the picture sequence frequency can thus be increased by approximately a factor of 40 as compared to a conventional TV half-frame. Naturally, the spatial resolution of the picture has suffered but only in the vertical direction, whereas the resolution in the line direction is of high quality. Thus, it is recommended to project the pictures of the processes to be recorded in such a way on the picture plane 5 of the camera so that the axis in which a high resolution is required runs parallel to the line direction. In another embodiment of the invention, an arrangement of two TV camera systems, with the same process being projected on the picture planes of both systems can be employed so that the systems differ from one another in such that the line direction of one camera system is perpendicular to the other. The video signals can be correlated by a computer. The video signals which are available at the output 8 of the video amplifier 7 for the scanning of only p lines per picture could be supplied immediately to a conventional TV receiver. A narrow band of 8 lines at the upper picture edge would result therefrom, containing the whole information of a picture and followed by more bands downwards, and originating from the following scanning cycles. The optical view of the processes is, however, not the main feature of the processes in question. Preferably, the video signals are digitized and stored in a data processing device for purposes of analysis. Then, for the optical representation of a synthetic picture of the process, the jumped-over lines could be completed either by a repetition of the information in the preceding lines or by an interpolation between successive lines. If the pitch fixed by the value p=8 is too coarse, the counter 14 can easily be switched to a greater value of p, such as 12, 13, 24, 26, 39, 52, 78 which are integer dividers of 312. Accordingly, the picture scanning can be provided in 0.77 ms, 9.83 ms, 1.53 ms, 2.66 ms, 3.33 ms, or 5 ms, respectively, rather than 0.5 ms. It is thus possible, depending on the speed of the process to be recorded, to determine the optimal time resolution with the best possible spatial resolution, by a simple adjustment of the counting capacity of the counter 14. It is also conceivable to move the scheme, for example, of the eight lines per picture from one scanning cycle to the next one, so that the interspaces between the lines of a picture are filled by succeeding scannings of the picture plane 5. The delay time of the delay means 16 has to be slightly changed to control the scanning of the picture plane 5 from one scanning cycle to the next one. As shown in FIG. 2, if this delay time is for example reduced by some microseconds, the picture change 22 appears as a fraction of a line scanning earlier and the first scanned line is vertically moved with respect to preceding scanning cycles. In the last line of FIG. 2, such a partially moved vertical deviation signal 26 is shown, in which the first picture cycle shown starts with line 1, the second with a later line and the third again with line 1, etc. Thus, for example, a picture of 8 lines such as explained above could be recorded, to first scan in the counting mode of the TV picture the lines 1, 79, 157, 235, 313, 391, 469 and 547, and in the next picture cycle scan a picture with the lines 40, 118, 196, 274, 352, 430, 508 and 586. Also in this case it is not important to produce an optically readable picture, since the filling-up of the gaps is carried out by information which has been recorded later and in rapid processes, this information does not correspond to the state during the scanning of the first picture. Such scanning cycles are however useful for the automatic digital picture evaluation, because their grade of actuality can be taken into account during the analysis of the observed process. In any case, processes can be analyzed in this way for which up to now very expensive film cameras with rotating mirrors had to be used, which however, as already mentioned, were not suited for an immediate analysis by a computer. The device of the invention is also suited for recording IR, UV or X-ray pictures.

The invention relates to a device for the optical recording of rapid proceses with a TV camera, which comprises means for deviating and suppressing the beam, in order to make the scanning beam run successively and cyclically over N lines of a picture plane on which the processes are projected. A cyclic line counter (14) carries out one counting step for each line pulse and supplies a counting end pulse after p line pulses respectively, N/p being in integer >>1. The end-of-count pulse is applied to the beam suppression circuit (13) of the TV camera (1) for the picture beam suppression and to a sawtooth generator (12), which controls the vertical deviation (4) of the beam.

big_patent

FIELD OF THE INVENTION [0001] The present invention relates to multimedia communications, and, in particular, relates to a particular technique for handling multimedia calls with clients having legacy phones and services. BACKGROUND OF THE INVENTION [0002] The world of telecommunications is evolving at a rapid pace. Consumers are perceived to demand new features, especially in the area of multimedia services. Sharing files, video conferencing, sharing a virtual white board, and similar activities are helpful in the business context as geographically dispersed personnel try to coordinate efforts on projects. While the business world may be the driving force behind the need for such multimedia services, the residential consumer may also desire to take advantage of these services. [0003] A few approaches have been proposed to provide integrated multimedia services. The first approach is to replace the customer premises equipment and network equipment with equipment that supports this functionality seamlessly. This approach is less than optimal for a number of reasons. First, it forces a large cost on the network providers and the consumers who have to replace costly, functioning equipment that, in many cases, is still well within its nominal life expectancy. Second, the older equipment has evolved over time until approximately three hundred different services are offered on this legacy equipment. After transitioning to the newer equipment, there will be a lag between deployment and reintegration of these services as new software must be written to implement the services on the new equipment. Many consumers of these services would not be happy with the loss of these services in the interim. Other drawbacks such as determining a standard or protocol and retraining users in the new hardware and software are also present. [0004] A second approach has been proposed by the assignee of the present invention and embodied in U.S. patent application Ser. No. 09/960,554, filed Sep. 21, 2001, which is hereby incorporated by reference in its entirety. That application provides a way to integrate multimedia capabilities with circuit switched calls. In the circuit based domain, this solution is functional. However, there remains a need for integrating multimedia capabilities in packet switched calls while preserving presently deployed network hardware. SUMMARY OF THE INVENTION [0005] The present invention provides a solution in the packet domain for integrating voice calls with multimedia sessions as a blended call. A blended call is a call which blends voice and multimedia functions into a single communication session. In an exemplary embodiment, a multimedia server is associated with a telephony server. The multimedia server has software incorporated therein that manages blended calls, using the functions of the multimedia server where appropriate and the telephony server where appropriate. To the multimedia server, there is a single session, but the session may have a voice component and a multimedia component. This software is sometimes referred to herein as a blender. In an alternate embodiment, the blender may be a function of sequential logic devices or other hardware that performs the same functions. [0006] Specifically, the present invention takes an incoming call from a remote caller that is received at a telephony server and accesses a database to determine if the intended recipient of the phone call has blended capabilities. If the answer is negative, the call is handled according to conventional protocols. If the answer is affirmative, the intended recipient supports blended calling, then the telephony server directs the call to a multimedia server, and particularly to a multimedia server with blender software associated therewith. The blender software receives the call request and initiates a single session with two call components: 1) a voice call component and 2) a multimedia call component. The voice call component is handled through the telephony server, and the multimedia call component is handled through the multimedia server. As used herein, the multimedia component includes all the non-voice parts of the call. As part of the two call components, two signaling paths are routed to the blender software, which may integrate the signaling paths into a single signal path as part of the single session, which is used by the multimedia server to control the bearer paths associated with the call. Further, when passing the voice call component back to the telephony server, the blender may include an indication that the component is being passed from the blender and that the telephony server is not to redirect or “loop” the signal back to avoid infinite loops between the blender and the telephony server. The indication to prevent the redirection or looping back may be a “loopback signal” such as a flag, information in a header, or other signaling technique. Additionally, the indication may not be a signal per se, but could be a persistent attribute such as call delivery via a specific trunk on the telephony server reserved for signals that have been processed by the blender. As used herein, the terms “loopback signal” and “loopback indication” cover such signals and indications. It should be appreciated that a loopback signal falls within the definition of a loopback indication as used herein. [0007] An outgoing call from a user that has blended capabilities may be processed at the telephony server and a destination address extracted to verify that the user is making a call. The telephony server, upon reference to a database to determine that the caller in this instance has blended capabilities, refers the call to a blender function on the multimedia server. The blender then initiates two call components: 1) a voice call component and 2) a multimedia call component. The multimedia server may handle both components as a single session, or may redirect or loop the voice call component back to the telephony server with an indication that the voice call component has been redirected back from blender processing. As noted above, the indication may be a loopback signal or loopback indication. [0008] While many systems may be used, the present invention is well suited for use with a Session Initiation Protocol for Telephones (SIP-T) configuration as the information included in the SIP-T messages contains the information helpful in setting up and tearing down the parallel call components. [0009] In another aspect of the present invention, an Intelligent Network (IN) signal may be used to determine if a blended call is being handled. If the call is a blended call, then the call is referred to the blender. If the call is not blended, the telephony server handles the call as normal. This embodiment effectively integrates the circuit based system described in the previously incorporated '554 application with the packet based approach of the present invention. [0010] Those skilled in the art will appreciate the scope of the present invention and realize additional aspects thereof after reading the following detailed description of the preferred embodiments in association with the accompanying drawing figures. BRIEF DESCRIPTION OF THE DRAWINGS [0011] The accompanying drawing figures incorporated in and forming a part of this specification illustrate several aspects of the invention, and together with the description serve to explain the principles of the invention. [0012] [0012]FIG. 1 illustrates a communication environment according to one embodiment of the present invention; [0013] [0013]FIG. 2 illustrates the methodology of an exemplary embodiment of an incoming voice call used in the present invention; [0014] [0014]FIG. 3 illustrates the methodology of an exemplary embodiment of an incoming multimedia call used in the present invention; [0015] [0015]FIG. 4 illustrates the methodology of an exemplary embodiment of an outgoing voice call used in the present invention; and [0016] [0016]FIG. 5 illustrates the methodology of an exemplary embodiment of an outgoing multimedia call used in the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0017] The embodiments set forth below represent the necessary information to enable those skilled in the art to practice the invention and illustrate the best mode of practicing the invention. Upon reading the following description in light of the accompanying drawing figures, those skilled in the art will understand the concepts of the invention and will recognize applications of these concepts not particularly addressed herein. It should be understood that these concepts and applications fall within the scope of the disclosure and the accompanying claims. [0018] The present invention is designed to prolong the viability of existing network devices by allowing existing customer premises equipment and existing network elements to be used to support multimedia capabilities. As used herein, a blended call is a call that supports voice and multimedia exchanges of information. To create the blended call, a telephony server or a multimedia server sends calls to blender software. The blender software initiates parallel voice and multimedia components with the customer premises equipment. The voice session may pass through the telephony server with an indication that blended processing has occurred. The blender further keeps control of the signaling paths of the parallel components so that the bearer path may be controlled to accommodate multimedia requests at any stage during the call. [0019] Because of the desire to be backwards compatible, the present invention may be used on any number of network systems using a number of different protocols. An exhaustive list of suitable networks and protocols is beyond the scope of the present discussion, but those of ordinary skill in the art will appreciate variations on the subject matter herein disclosed after a review of an exemplary embodiment, which is based on a session initiation protocol (SIP) environment. [0020] A communication environment 10 capable of carrying out the concepts of the present invention is illustrated in FIG. 1. The communication environment 10 depicted includes a communication network 12 , which may preferably include a packet switched network with SIP enabled devices. Thus, the network may include any type of packet switched network having devices using SIP to facilitate communications between two or more devices, also referred to herein as a SIP enabled network. [0021] Two clients 14 , 16 are connected to the communication network 12 . Each client 14 , 16 may have customer premises equipment (CPE) 18 associated therewith, denoted 18 A for client 14 and 18 B for client 16 . Specifically, client 14 may have a telephone type device 20 and a computer type device 22 . Client 16 may have a telephone type device 24 and a computer type device 26 . [0022] In general, the telephone type devices 20 , 24 are directed to voice communications with limited data options such as displaying a number called, a calling number, time elapsed and other common telephony functions. In contrast, the computer type devices 22 , 26 may have a monitor, a keyboard, user input devices, and other conventional computer features such that a user may provide inputs and receive outputs and particularly generate and view multimedia content on the computer type device 22 , 26 . It is possible that a telephone type device 20 , 24 could be integrated with its corresponding computer type device 22 , 26 into a single piece of customer premises equipment 18 with the functionalities of both devices. [0023] Telephone type devices 20 , 24 and computer type devices 22 , 26 may contain data processing devices such as microprocessors which implement software that may be stored on any appropriate computer readable medium such as memory, floppy disks, and compact discs. Alternatively, the functionality of the present invention may be stored in sequential logic as is well understood. The telephone type devices 20 , 24 may, if desired, be “dumb” SIP terminals, H.323 terminals, or other devices delivering primarily voice based service. Each piece of customer premises equipment 18 may be a user agent within the SIP enabled network. As the telephone type devices 20 , 24 and the computer type devices 22 , 26 do not have a full range of features, they may be referred to as feature limited user agents. [0024] Clients 14 , 16 are connected to the communication network 12 by one or more connections 28 . These connections 28 may be wireless or wirebased. In the event that they are wirebased, copper line, fiber optic line, or other comparable communication medium may be used. It is preferred that the connection 28 be a wideband connection, suitable for exchanging large amounts of information quickly. Note further that while multiple connections are shown, a single connection may in fact provide all the communication links to the customer premises equipment 18 . [0025] At some point in the communication network 12 , the connection 28 from the telephone type device 20 , 24 terminates on a telephony server, such as telephony servers 30 , 32 . The telephony servers 30 , 32 may be the CS2000 or DMS100 sold by Nortel Networks Limited of 2351 Boulevard Alfred-Nobel, St. Laurent, Quebec, Canada, H4S 2A9. Other class five telecommunication switches or comparable devices including a PBX or a KEY system could also be used as needed or desired and may support both circuit switched voice calls and voice over packet calls. The telephony servers 30 , 32 may communicate with one another and other components in the communication network 12 via a Session Initiation Protocol for Telephones (SIP-T). SIP-T is fully compatible with other SIP enabled devices. Still other communication protocols could be used if needed or desired. [0026] Each telephony server 30 , 32 may be connected to or integrated with a database (DB) server 34 , 36 . The database servers 34 , 36 may track which clients support which services. For example, a client 14 may support blended services, call forwarding, and the like, each of which is noted in the database server 34 . The database server 34 may index the entries by a trunk line, a directory number, or other unique identifier as is well understood. [0027] Other components of the present invention are multimedia servers (MS) 38 , 40 which may be positioned throughout the communication network 12 as needed to provide the appropriate quality of service for the present invention. Multimedia servers 38 , 40 are sometimes referred to in the industry as media portals and may be the Interactive Multimedia Server (IMS) sold by Nortel Networks Limited. The IMS is based on JAVA technology and is a SIP enabled device capable of serving SIP clients by providing call conferencing, call transfers, call handling, web access, whiteboarding, video, unified messaging, distributed call centers with integrated web access and other multimedia services. Other media portals or multimedia servers may also be used if needed or desired. [0028] Operating off of the data processing devices of the multimedia servers 38 , 40 is software that embodies blenders 42 , 44 respectively. An exemplary blender 42 , 44 is further explicated in commonly owned U.S. patent application Ser. No. 10/028,510, filed Dec. 20, 2001, which is hereby incorporated by reference in its entirety. The '510 application refers to the blender as a combined user agent. The present invention builds on the functionality described in the '510 application by showing how the telephony server and the multimedia server interact in response to commands from the blender. As an alternative to software, the blenders 42 , 44 may be instructions embedded in sequential logic or other hardware as is well understood. [0029] The present invention takes incoming and outgoing calls associated with a client, such as client 14 , and routes the call to the blender 42 associated with the telephony server 30 . The routing to the blender 42 may be done by standard telephony interfaces such as an ISUP trunk, a Primary Rate Interface (PRI) link, a Public Telephone Service (PTS) trunk, or more preferably a SIP or SIP-T connection. The blender 42 then initiates two parallel components for the call. The first component is a voice component and the second component is a multimedia component. Each component may be established with the corresponding piece of customer premises equipment 18 A, and the signaling paths pass through and are controlled by the blender 42 . A more detailed exploration of this is presented below. [0030] It should be appreciated that the various components within the communication network 12 may communicate with one another even though specific connections are not illustrated. This reflects that in a packet network, the connections are frequently virtual and may change over time or between packets depending on load, router availability, and similar network traffic conditions. Further, the SIP enabled network may have gateways to the Public Switched Telephone Network (PSTN), the Public Land Mobile Network (PLMN), and the like. As the particular network and protocol are not central to the present invention, a further discussion of these well known elements is foregone. Also, the particular connections to the client 14 may be varied. For example, a single Digital Subscriber Line (DSL) into a location may serve both the telephone type device 20 and the computer type device 22 . Alternatively, the telephone type device 20 may be served by a phone line and the computer type device 22 served by a cable modem or the like as is well understood. [0031] Before turning to the details of the present invention, an overview of SIP may be helpful, as the following discussion is couched in terms of the commands used by SIP. The specification for SIP is provided in the Internet Engineering Task Force's Request for Comments (RFC) 3261: Session Initiation Protocol Internet Draft, which is hereby incorporated by reference in its entirety. A SIP endpoint is generally capable of running an application, which is generally referred to as a user agent (UA), and is capable of facilitating media sessions using SIP. User agents register their ability to establish sessions with a SIP proxy by sending “REGISTER” messages to the SIP proxy. The REGISTER message informs the SIP proxy of the SIP universal resource locator (URL) that identifies the user agent to the SIP network. The REGISTER message also contains information about how to reach specific user agents over the SIP network by providing the Internet Protocol (IP) address and port that the user agent will use for SIP sessions. [0032] A “SUBSCRIBE” message may be used to subscribe to an application or service provided by a SIP endpoint. Further, “NOTIFY” messages may be used to provide information between SIP endpoints in response to various actions or messages, including REGISTER and SUBSCRIBE messages. [0033] When a user agent wants to establish a session with another user agent, the user agent initiating the session will send an “INVITE” message to the SIP proxy and specify the targeted user agent in the “TO:” header of the INVITE message. Identification of the user agent takes the form of a SIP URL. In its simplest form, the URL is represented by a number of “<username>@<domain>”, such as “janedoe@nortelnetworks.com.” The SIP proxy will use the SIP URL in the TO: header of the message to determine if the targeted user agent is registered with the SIP proxy. Generally, the user name is unique within the name space of the specified domain. [0034] If the targeted user agent has registered with the SIP proxy, the SIP proxy will forward the INVITE message directly to the targeted user agent. The targeted user agent will respond with a “200 OK” message, and a session between the respective user agents will be established as per the message exchange required in the SIP specification. Media capabilities are passed between the two user agents of the respective endpoints as parameters embedded within the session setup messages, such as the INVITE, 200 OK, and acknowledgment (ACK) messages. The media capabilities are typically described using the Session Description Protocol (SDP). Once respective endpoints are in an active session with each other and have determined each other's capabilities, the specified media content may be exchanged during an appropriate media session. [0035] Against this protocol backdrop, FIG. 2 illustrates a flow chart of the methodology of an incoming call to a blended client 14 . In particular, a client 16 dials a number for the client 14 on the telephone type device 24 (block 100 ). The telephony server 32 receives the dialed number (block 102 ) as is conventional. The telephony server 32 references the database server 36 to learn that telephony server 30 serves the dialed number (block 104 ). The telephony server 32 contacts the telephony server 30 with the call request (block 106 ). So far, the call processing is performed according to any conventional protocol and over any conventional network hardware. [0036] When the telephony server 30 receives the call request, the telephony server 30 references the database server 34 about the number dialed (block 108 ) to determine if the number dialed supports blended services (block 110 ). If the answer to block 110 is “no”, blended services are not supported, the telephony server 30 rings the client 14 conventionally (block 112 ). [0037] If, however, the answer to block 110 is “yes”, the dialed number does support blended services, then the telephony server 30 passes the call request to the blender 42 in the multimedia server 38 (block 114 ). The blender 42 issues an INVITE message (hereinafter “invite”) to the multimedia server 38 (block 116 ). The multimedia server 38 performs call disposition handling including offering the call to client 14 (block 118 ). Call disposition handling may include for example a “find-me, follow-me” function, call blocking, routing to voice mail based on call screening criteria, updating a user's presence-state information, and the like. [0038] The multimedia server 38 sends an “invite” to the client 14 via the blender 42 (block 120 ). The blender 42 separates the “invite” into a call request and a multimedia request (block 122 ). The requests may be INVITE messages according to the SIP standard. The blender 42 sends the call request back to the telephony server 30 which rings the telephone type device 20 (block 124 ). The blender 42 may, as part of sending the call request back to the telephony server 30 , include indicia or otherwise provide an indication that designates that the call request is coming from the blender such that the telephony server 30 does not redirect or otherwise loop the call request back to the blender 42 as would be normal for an incoming call. These indicia may take any appropriate form such as a flag, information in the header, a persistent condition, or other technique, and prevent an infinite loop from forming between the telephony server 30 and the blender 42 . [0039] The blender 42 sends the multimedia request to the computer type device 22 (block 126 ). The multimedia server 38 maintains control over the signaling paths associated with the blended session. In an exemplary embodiment, the blender 42 merges the signaling paths of the voice component and the multimedia component into a single signaling path and passes the merged signaling path to the multimedia server 38 as a single session. By having access to the signaling path of the session, the multimedia server 38 may control the bearer paths of the components without having to parse the information in the bearer path. [0040] Note that because SIP is being used, the multimedia server 38 has access to the Uniform Resource Locators (URLs) of the endpoints of the call (the respective clients 14 , 16 ), the capabilities of the clients 14 , 16 , and other information relevant to the call disposition handling. Other protocols may provide the same information, but SIP is particularly well suited for this task. [0041] [0041]FIG. 3 illustrates an incoming multimedia call methodology. The client 16 desires to instant message (IM) the client 14 . To achieve this, the client 16 IM's the client 14 with computer type device 26 (block 150 ). The IM request may include an address for the client 14 , an indication that the client 16 supports blended capabilities and other SIP information. The multimedia server 40 receives the IM request (block 152 ) and references a database (not shown explicitly) to learn that multimedia server 38 serves the address (block 154 ). [0042] The multimedia server 40 contacts the multimedia server 38 with the IM request (block 156 ). The multimedia server 38 sends an “invite” to client 14 via the blender 42 (block 158 ). The blender 42 separates the “invite” into a call request and a multimedia request (block 160 ). The call request is passed to the telephony server 30 with indicia that the call request is coming from the blender 42 (block 162 ) to prevent the creation of an infinite loop. The telephony server 30 sends an “invite” to the telephone type device 20 (block 164 ). At this point the telephone type device 20 may not ring, but it may answer the “invite” to set up the signaling path associated with the provision of call services. The blender 42 also sends an “invite” to the computer type device 22 (block 166 ). The answers from the telephone type device 20 and the computer type device 22 arrive at the blender 42 (block 168 ), which merges them into a single signaling path and delivers the signaling path to the multimedia server 38 . The multimedia server 38 then manages the call (block 170 ) by maintaining control over the signaling path and allowing the bearer path to be routed through the communication network 12 as needed. If at any point one of the clients 14 , 16 wishes to establish a voice connection, the signaling path for the voice session is already in existence through the blender 42 and may be activated. Alternatively, the invitation for the voice component may only be generated upon request by the users. Thus, the IM session may continue as normal until a user decides to speak with the other party. Upon issuing the appropriate command to the computer type device 22 , the blender 42 receives the request to activate the voice component. [0043] [0043]FIG. 4 illustrates the methodology of an outgoing voice call from a client 14 . The client 14 dials a number with the telephone type device 20 (block 200 ). The telephony server 30 receives the dialed number (block 202 ). The destination address is extracted by the telephony server 30 (block 204 ) to determine that the client 14 is actually making a call rather than activating a call handling feature such as call forwarding, programming a speed call number, or similar features. The call can be a speed call activation, a normally dialed number, or other technique such that an indication is made that there is a call and not a call handling feature. The telephony server 30 references the database 34 (block 206 ) and determines if the client 14 supports blended services (block 208 ). [0044] If the answer to block 208 is “no”, the client 14 does not support blended services, the call is processed conventionally (block 210 ). If however, the answer to block 208 is “yes”, the client 14 does support blended services, the telephony server 30 passes the call to the blender 42 (block 212 ). The blender 42 sends an “invite” to the computer type device 22 (block 214 ). The computer type device 22 accepts (block 216 ). Note that a bearer path may not exist yet to the computer type device 22 , but the signaling path associated with the provision of the multimedia session may be created such that if the client 14 desires to begin using multimedia services, they are readily available. The blender 42 passes the combined signal to the multimedia server 38 (block 218 ). The multimedia server 38 performs call disposition handling and sends an “invite” to client 16 (block 220 ). The multimedia server 38 may route the voice portion of the call back through the telephony server 30 if needed or desired, or may handle that portion itself. Other arrangements could also be made. Note also that the invitation to the computer type device 22 may not be issued until a function is invoked that necessitates the provision of multimedia services. [0045] [0045]FIG. 5 illustrates an exemplary method of an outgoing multimedia call from the client 14 . The client 14 desires to instant message the client 16 and sends an IM to client 16 with the computer type device 22 (block 250 ). The multimedia server 38 receives the multimedia request (block 252 ). The multimedia server 38 may reference a database (not shown explicitly) to determine which multimedia server serves the destination address of the IM request (block 254 ). The multimedia server 38 sends an invitation to the client 14 via the blender 42 (block 256 ). [0046] Concurrently with the invitation to the client 14 , the multimedia server 38 sends an “invite” to the multimedia server 40 (block 258 ). The multimedia server 40 then invites the client 16 to join the call (block 260 ). The blender 42 is meanwhile separating the “invite” to the client 14 into a call request and a multimedia request (block 262 ). The blender 42 invites the telephone type device 20 and the computer type device 22 (block 264 ) to join the call. Note that the original request from the computer type device 22 may cause the multimedia request to subsume into the original request. Further, the “invite” to the telephone type device 20 may be routed through the telephony server 30 and have a loopback signal or a loopback indication that prevents the formation of an infinite loop between the telephony server 30 and the blender 42 . [0047] The blender 42 passes the combined signaling path from the telephone type device 20 and the computer type device 22 to the multimedia server 38 (block 266 ) and the multimedia server 38 connects the signal from the blender 42 with the signal from the multimedia server 40 and performs call disposition handling (block 268 ). Again, it is possible that the telephony server 30 may not pass the invitation to the telephone type device 20 until that function is invoked by the participants. [0048] As another embodiment, instead of relying on SIP for all of the trigger commands, the present invention may be integrated with an Intelligent Network (IN) such that for basic call disposition handling, the IN triggers and commands are used. For mid-call activation of multimedia features, the fact that the multimedia server 38 has access to the signaling path allows the multimedia server 38 to provide the requested multimedia services. For more information on the use of the IN as a trigger point, see the previously incorporated '554 application. [0049] Note that while the processes above have been described in a generally linear fashion, it is within the scope of the present invention to rearrange the order of some of the steps such that they occur concurrently or in different orders where needed or desired. [0050] Those skilled in the art will recognize improvements and modifications to the preferred embodiments of the present invention. All such improvements and modifications are considered within the scope of the concepts disclosed herein and the claims that follow.

A communications system that supports multimedia components is easily adapted to existing network elements. Voice components arriving at or coming from a user having multimedia capabilities are referred from a telephony server serving the user to a multimedia server. A determination is made as to whether the other party supports multimedia capabilities. If that determination is negative, the component is passed back to the telephony server with an indication that the session is coming from the multimedia server to avoid an infinite loop. If the determination is positive, a parallel multimedia component is established between the parties while the multimedia server remains aware of the bearer path.

big_patent

RELATED APPLICATIONS [0001] The present invention is related to concurrently filed, commonly assigned, application Ser. No. ______ [Attorney Docket No. 10018268-1], entitled Smart Phonebook Search; and application Ser. No. ______ [Attorney Docket No. 10018267-1], entitled Smart Content Information Merge and Presentation; the disclosures of which are each incorporated herein by reference in their entireties. FIELD OF THE INVENTION [0002] The present invention generally relates to electronic service delivery and specifically to content synchronization frameworks using dynamic attributes and file bundles for connected devices. BACKGROUND [0003] Existing methods for data synchronization between a device and a server are generally carried out based on a predefined set of attributes. Typically, data synchronization on the basis of an arbitrary set of attributes, either internal or external to the synchronization framework, is not supported. Similarly, geographically distributing data sets is impractical employing existing synchronization methods and systems. [0004] Also, existing data synchronization methods do not determine how and in what order the data synchronization is carried out. For example, existing synchronization frameworks do not provide data synchronization on the basis of random or otherwise arbitrary attributes that may influence priority ordering of data synchronization (e.g. that data set of highest priority or highest business value should be synchronized first). [0005] Typically, existing data synchronization methods do not provide a mechanism to logically “bundle” related data sets into logical units. Thus, it is not possible to attach a meaningful action to a group of files to be synchronized or to execute any arbitrary program and/or script after successful synchronization of a group of files. [0006] Additionally, with existing data synchronization approaches, in the event of connection disruption between a client device and a server, resumption of data synchronization from the specific bundle that experienced the failure during the last connection disruption is not supported. Problematically, in existing data synchronization methods the synchronization server performs most of the processing and returns responses to clients. Typically these responses are not optimally compressed for lower bandwidth communication, making existing synchronization framework architectures relatively unscalable. In addition, existing methods do not support caching of most common server responses to make data synchronization more efficient. SUMMARY OF THE INVENTION [0007] One embodiment of a content synchronization method for connected devices comprises accepting, by a central reference point, context from a connected client device, constructing, by the central reference point, at least one response in a semantic compatible with the connected device and compatible with a user of the connected device the response comprising at least one file description bundle, prioritizing, by the central reference point, download order of files described in the at least one response bundle, downloading the files described in the at least one response bundle, to the connected device in the download order, confirming complete download of the files described in the at least one response bundle, and rejecting incompletely downloaded bundles of files. [0008] An embodiment of a content synchronization framework comprises a central reference point processing synchronization requests from connected client devices and returning responses to the connected client devices including, at least in part, bundles identifying files to satisfy the synchronization requests, at least one server hosting the files for use by the connected devices in various contexts, software sending a current context of a connected client device to the central reference point, the software adapted to be hosted by the connected client device, and network connectivity communicating the context from the connected device to the central reference point and communicating the responses from the central reference point to the connected device. [0009] A further embodiment of a content synchronization method for connected devices comprises sending, by a connected device, a synchronization request comprising, at least in part, context and dynamic attributes of the connected device, accepting, by a central reference point, the synchronization request, constructing, by the central reference point, at least one response bundle, comprised at least in part of file identifications, in a semantic compatible with the connected device, prioritizing, by the central reference point, download order of the files identified in the response bundles, responding to the connected device, by the central reference point, to the synchronization request with a synchronization response comprising the at least one response bundle, creating, by the client device, a delta list of bundle files including bundle files to replace out-of-date bundle files on the client device and bundle files not present on the client device, downloading the files indicated in the delta list to the connected device in the download order, overwriting copies of the bundle files present on the client device with the downloaded bundle files, confirming complete download of the bundles, and rejecting incompletely downloaded bundles. BRIEF DESCRIPTION OF THE DRAWING [0010] [0010]FIG. 1 is a diagrammatic representation of a synchronization framework in accordance with the present invention; [0011] [0011]FIG. 2 is a flowchart of a synchronization method embodiment in accordance with the present invention; [0012] [0012]FIG. 3 is a diagrammatic representation of a synchronization response in accordance with the present invention; [0013] [0013]FIG. 4 is a diagrammatic representation of data flow in accordance with the present systems and methods; and [0014] [0014]FIG. 5 is a flowchart of another synchronization method embodiment in accordance with the present invention. DETAILED DESCRIPTION [0015] The present invention is directed to systems and methods for a content synchronization framework that allows any connected device or appliance, such as a personal computer (PC), portable computer, personal digital assistant (PDA) or the like, to perform contextual synchronization over a wide variety of communication network topologies including both wired and wireless connections. Preferably, the present systems and methods make use of transport optimization such as data compression to save bandwidth and time over low bandwidth connections such as dial-up connections. The present synchronization framework provides a central reference point, such as a server or group of servers, and each communicating device, preferably synchronizes to the content determined by this central reference point. Preferably, the present invention is highly scalable, preferably due to the client device performing a major portion of processing. The present invention is also preferably deployable worldwide with support for multiple languages and character sets from a central reference point and distributed content servers. The present framework preferably supports both synchronous and asynchronous interaction between the central reference point and connected devices or appliances. Preferably, the present invention enables a client device to have the latest and most relevant content at all time, based, at least in part, on a user's and/or device's context. This context is preferably expressed by the device to the central reference point as dynamic attributes that are subject to change during later synchronizations. [0016] The present systems and methods preferably have flexibility to support content synchronization, at any point in time, based on device context. This context may be in the form of arbitrary dynamic attributes sent to a central reference point by the client. This enables synchronization of content that is current and relevant to the user's device. Also, the present systems and methods preferably employ file compression and concurrent priority based downloading to further optimize the present synchronization algorithm and to optimize communication bandwidth usage. [0017] With attention directed to FIG. 1, synchronization framework 100 preferably has four major components, namely, client 101 , at least one central reference point server 105 , a network, such as Internet 106 and external partners 108 . Synchronization framework 100 allows various client devices or appliances 101 , such as a personal computer 102 including attached peripherals 107 , handheld/palmtop devices 103 , portable computer 104 , and the like, to synchronize a variety of content, such as files, patches, graphics, or the like, preferably arranged in bundles, from synchronization servers 109 and/or external partners 108 over network connectivity, such as via Internet 106 . As will be appreciated, other network connectivity arrangements, such as an intranet or dial-up connection, may be used to practice the present invention. Server 105 preferably hosts, or acts as, a central reference point in accordance with the present invention but may also host content as well. Client 101 and server 105 host algorithms of the present systems and methods, while Internet 106 is used for communication purposes between central reference point 105 , client 101 , external partners 108 and/or download server(s) 109 . External partner server 108 may be a system of an external entity or enterprise that central reference point 105 may communicate with to obtain additional context attributes or content to assist in providing responses to client 101 . [0018] Turning to FIG. 2, while performing synchronization 200 , a client device preferably shares, at box 201 , contextual information or dynamic attributes such as, device location, device type and any arbitrary attribute values with the central reference point, via a synchronization request. Other dynamic attributes may include client operating system, client locale, client device type, city, state abbreviation, zip code, language code, country code, area code, phone number, telephone country access code, peripheral type, peripheral manufacturer, peripheral model, peripheral stock keeping unit, build identification, peripheral purchase channel, application version, offer locale, user interface locale, a frontend version of an associated service delivery platform, or the like. As noted above, the central reference point is preferably hosted by a server in accordance with the present systems and methods. The request is preferably confirmed by the central reference point to verify that the request came from a valid client, at box 202 . This check preferably validates security information embedded in a message header of the request or the like. This security information is preferably encrypted employing a key that only a valid client and server possess. However, any number of verification techniques may be used, such as public key encryption, digital signature certificates and/or the like, if desired. If the request is invalid, an error response is preferably sent back to the client at box 203 , indicating the client is not authorized to use the synchronization framework. [0019] If the request is verified, contextual information attributes in the request are preferably used by the central reference point and may be combined with additional arbitrary attributes collected from an external partner system to compile bundle information for the requesting client at box 204 . The content of such a bundle is preferably based on the dynamic arbitrary attribute information provided as a part of the request. In box 205 , the central reference point preferably composes a response made up of zero or more bundles structured as discussed below in relation to FIG. 3, with the bundle files listed in an order of priority for the client device. The bundles each preferably describe location and properties of any content types such as executable files, libraries or any data type. The bundles preferably package this description in a semantic understood and/or used by the client an/or the client device or appliance. Thus, the present systems and methods are well adapted to support multiple languages and/or appliance operating systems on a single system server acting as, or hosting, the aforementioned central reference point. [0020] To support limited bandwidth and limited connection time over a dial-up or similar connections, the present systems and methods preferably employ data compression for responses at 205 . Reducing the size of data files transmitted allows faster communication between the central reference point and client device even over a standard telephone dial-up connection. [0021] Employing the response from box 205 , the client device preferably composes a delta list of all the files in the bundle that are different from local copies available to the client device, box 206 . This difference is preferably determined by a checksum property of the file, or the like, indicated in the bundle (see discussion below in relation to FIG. 3, checksum 314 ). The delta list is preferably comprised of files not locally available to the client device or for which a bundle provides a newer version. The download priority order of the bundle assigned by the central reference point is preferably retained in the delta list. The client preferably retrieves the files in the ordered delta list at box 207 from various servers indicated in the bundles, such as the central reference point, download servers and external partners. The files downloaded at 207 are also preferably compressed to save download time over slow and/or low bandwidth connections. If a file is compressed, a file action will preferably indicate that the files should be uncompressed. If a bundle contains only compressed files, bundle actions will preferably indicate that the bundle itself needs to be uncompressed. Such bundle and file actions are discussed in relation to FIG. 3 below. [0022] In the event of communication connection failure, incomplete bundles, as determined at 208 , are rejected at box 210 . A determination is made at 211 as to whether all bundles to be downloaded have been successfully downloaded. If it is determined at 211 that there are more bundles to be downloaded, the present method returns to step 207 to download those bundle files. However, if it is determined at 211 that all bundles have been downloaded, synchronization 200 ends at 212 . If during a previous synchronization session a client was not able to download all the bundles in the delta list generated by the client device, the client device will preferably download bundles that failed to download in the previous session, during a subsequent synchronization. This improves the efficiency of the framework as synchronization session resumption is at the bundle level. In essence, the client device can continue synchronization where it left off during the previous, failed or disrupted session. [0023] Received bundles may be acted on in various manners, such as via actions indicated by an install URL (uniform resource locator) or via file actions associated with bundle files. Bundle files are also preferably synchronized over any local copy of the bundles on the client device at box 209 , so that the latest version of files are available for the device. Synchronization process 200 ends at 212 . [0024] The present content synchronization frameworks preferably provide for creation of the aforementioned delta list embodying differences between a client's local copy of a file or data and the central reference point indicated file or data at box 206 . Creation of this delta list is preferably performed by the client device and thus the present systems and methods are highly scalable as the work is distributed instead of being carried out by one server. Also, this distribution of work to the client means that the central reference point server does not need to store the state of each client device since the appliance preferably creates and maintains this delta list. [0025] [0025]FIG. 3 is a diagrammatic illustration of the contents of a synchronization response 300 made up of bundles 301 . FIG. 3 shows the relationship of response 300 to bundle 301 and the contents of a bundle, descriptions of files 302 . Preferably, a synchronization response 300 , may contain zero or any number of bundles. [0026] Each bundle 301 preferably contains a set of properties 303 that directs the client device in understanding the content and properties of files 302 named in bundle 301 . Bundle properties 303 preferably tell the client device locations of files 302 in the bundle by indicating download sites 304 and/or host sites 305 where files are located. Any number of such sites may be employed to host content files and listed as sites 304 and 305 . Hence, it is possible to distribute files 302 throughout the world. This potential diversity gives the present systems and methods a highly scalable and reliable architecture; since if any one server fails, the client can obtain bundle files 302 from a next listed server. Bundle properties 303 preferably list download priorities 306 for files 302 . This may facilitate downloading of the most important files first and may facilitate handling of inter-bundle dependencies, such as a file that requires another file for proper installation (e.g. a driver needed to run a program file). Bundle actions 307 preferably inform the client device of actions that need to be performed on the bundle after it has been downloaded. For example, if the bundle is compressed, a bundle action instruction to decompress the bundle may be included in a header of the bundle to indicate to the client device that it needs to uncompress the bundle. Bundle actions 307 may take the form of a script to execute after bundle 301 is downloaded. Multiple bundle actions 307 may be listed in bundle actions properties 303 . Since bundle 301 is comprised of a listing of files 302 , file inter-dependence such as an executable (.exe) file that requires a dynamic link library (.dll) file, may be encapsulated in a same bundle. As indicated above, the present systems and methods will preferably reject all files in a bundle if all the bundle files are not downloaded, complete. Thus, inter-file dependencies are maintained intact by the present systems and methods. [0027] File descriptions 302 also preferably have properties that help the client determine if the subject file is new and that aid in processing the file. File properties 308 preferably include a file name 310 and install URL 311 property, which preferably indicates to the client device the location of the file on the device's local file system. File description 302 also preferably has file size property 312 and checksum property 314 , which indicates to the client whether the file is newer or different from a client device local copy of the file. If checksum 314 and size 312 is found to be different from any local copy of the file, during process 200 above, then the client preferably downloads the file. The file also has actions property 315 which may tell the client device what to do with a file, for example: copy the file to the location indicated by install URL 313 after download; or, decompress the file, move the decompressed file to a specified location and execute the decompressed file. File actions 315 are preferably in an ordered list of actions which facilitates scripted handling of files once the files are downloaded (e.g. having two actions carried out on a file, one before the other). [0028] Flow of content and data between the components involved in a synchronization request and response is diagrammatically illustrated in FIG. 4 and broadly designated by reference numeral 400 . As discussed above, handling of a synchronization request and response involves: the client 101 ; synchronization server 105 , which acts as or hosts a central reference point; and optional partner servers 108 . Preferably, presence or absence of partner(s) 108 is based on business logic and the client's dynamic arbitrary attributes which may indicate that a partner system 108 should be used by central reference point 105 . For example, if the attributes of the client device indicate that it is a desktop personal computer that has a CD-RW (compact disk-read/write) drive, then a partner that has files pertinent for synchronization for that CD-RW drive, such as drivers for the CD-RW drive, may be involved in synchronization 400 . In such a case, central reference point 105 preferably shares some attributes of the client device with partner server 108 to determine content for bundles presented to the client device. In the above example, such attributes might include a model designation of the CD-RW drive. The flow of information and data in FIG. 4 is detailed below. [0029] Client device 101 preferably collects attributes 401 , information about itself and its environment, for example, the device's configuration and geographical location. Using attributes 401 , device 101 composes request 402 with a set of profiles having arbitrary attributes 401 that it determines dynamically at the runtime of request 402 . Request 402 is sent to central reference point 105 via any of one or more forms of connectivity such as the Internet; a dial-up connection that may be initialed by use of a smart dialer as disclosed in above referenced patent application Ser. No. ______ [Attorney Docket No. 10018268-1] entitled Smart Phonebook Search; or an existing LAN connection. [0030] Central reference point server 105 preferably processes request 402 by analyzing ( 403 ) request 402 and included attributes 401 to determine bundles needed to fulfill request 402 and whether further information is needed from partner server(s) 108 . For the example of FIG. 4, it is assumed analysis 403 of request attributes indicate that more information from partner server(s) 108 is desirable. Central reference point server 105 preferably sends additional information request 404 to partner system 108 with a limited subset of request attributes 401 supplied by client device 101 . Additional information request 404 preferably only has information needed by partner server 108 . Additional request 404 is preferably sent over the Internet, other network, or via a dial-up connection, such as described above, in either a secure or plain text method depending on the nature of partner server 108 and/or the client. Preferably, central reference point server 105 will wait for a limited predetermined time for a response from partner server 108 to avoid delaying a response back to client device 101 . [0031] Partner server 108 preferably analyzes the subset of information making up additional request 404 , at 405 , and composes supplemental response 406 preferably made up of supplemental attributes for client device 101 . Preferably response 406 is sent back to central reference point server 105 via the internet, other network, or the aforementioned dial-up connection. [0032] Central reference point server 105 preferably processes the supplemental attributes of supplemental response 406 , at 407 , and finds additional bundles or removes inappropriate bundles for response 408 for client device 101 . The partner server supplemental response 406 may also result in reordering of bundle priority or recomposition of bundles by central reference point 105 . Synchronization response 408 is then sent to client device 101 by central reference point 105 . Response 408 preferably contains bundles, including bundle and file properties, such as described above in relation to FIG. 3. Response 408 is preferably compressed to ensure that it may be sent quickly. [0033] Client device 101 preferably uncompresses response 408 and at 409 verifies the client's local copies of bundle indicated files against the server response bundle file properties and composes a delta list of bundles and/or files to retrieve, as discussed above in relation to FIG. 2. Client device 101 downloads ( 410 ) bundle files, in the order indicated by central reference point server 105 , from servers indicated in the response bundles, and replaces any local copies of the files with the new retrieved files. [0034] Central reference point synchronization server 105 can also preferably cache responses. Therefore, by way of example, if a number of client devices send synchronization requests with the same arbitrary attributes, central reference point server 105 can send cached responses without further analysis or querying of partner systems 108 at the time of each request, thereby decreasing response times and increasing scalability of framework 100 . [0035] Turning to FIG. 5, synchronization 500 is based on gathered information. Client 500 a and server 500 b are initialized employing components of an SDP application in accordance with the present invention at boxes 501 and 502 , respectively. The server awaits requests from clients at box 503 following initialization at box 502 . The client creates context for the client appliance at box 504 . This context may include a device profile, an attached peripheral profile, a user profile, geographical location, communication infrastructure, and/or other pertinent information. The client sends contextual data to the synchronization server at box 505 , and waits at box 506 for a response from the server. The synchronization server receives the client request at box 507 and uses this information to create list(s) of “bundles” and prepares an extensible markup language (XML) response from the sever to the synchronizing client. A bundle according to the present invention is preferably a logical unit that defines at least one set of files, preferably of any type, and the files contexts or characteristics. [0036] The response built at box 508 and sent by the synchronization server at box 509 is preferably a map of bundles for a given context and for a given client. One embodiment of synchronization process 500 employs an “updating” phase. During this phase downloaded files are copied to an appropriate location in the SDP application. Information concerning location of the files is present in server responses built at 508 as part of a bundle description and sent to the client at box 509 . Upon sending the map of bundle information at box 509 the server preferably returns to waiting for client requests at box 503 . Upon receiving the response at box 510 , the client determines the list of bundles to be updated. To achieve this, the client preferably creates a local “snapshot” of bundles it posses at box 511 , compares the snapshot with the server's response and creates a list of bundles and/or files within bundles to be downloaded at box 512 , preferably this list is limited to those files that need to be updated at box 512 . The list is preferably created based on server assigned download priority. If the list created at box 512 is found to be empty at 513 , the process ends for the client at 518 . However, if the list created at box 512 is not found to be empty at 513 , the list is sent to the server at box 518 as a request for each file in the listed bundles. [0037] Based on download priorities of each bundle, files are preferably downloaded in descending order of download priority at box 514 . In the illustrated preferred embodiment of the present system and method, synchronization process 500 is adaptive. Preferably, if during the download process, the download of a file fails at box 515 , the entire associated bundle is rejected and the process moves on to download the next bundle at box 516 . If at 517 it is determined that all listed bundles have been downloaded, then the process ends at 518 . However, if additional bundles are found to be remaining at 517 , i.e., not all listed bundles have been downloaded, the next bundle is requested at box 514 . Download steps 514 through 517 repeat until all listed bundles are found to have been downloaded at 517 and process 500 ends at 518 . A client may further optimize the downloading order by considering communication speed and/or geographical proximity of download sites. This process facilitates efficient downloading of complete bundles.

A content synchronization method for connected devices comprises accepting, by a central reference point, context from a connected client device, constructing, by the central reference point, at least one response in a semantic compatible with the connected device and compatible with a user of the connected device the response comprising at least one file description bundle, prioritizing, by the central reference point, download order of files described in the at least one response bundle, downloading the files described in the at least one response bundle, to the connected device in the download order, confirming complete download of the files described in the at least one response bundle, and rejecting incompletely downloaded bundles of files.

big_patent

CROSS REFERENCE TO RELATED APPLICATION [0001] The present application is a continuation of U.S. patent application Ser. No. 11/602,491 filed Nov. 21, 2006, which in turn claims priority under 35 U.S.C. §119(e) to U.S. provisional patent application No. 60/597,297 filed Nov. 21, 2005. Each application is incorporated herein by reference. FIELD OF THE INVENTION [0002] The present invention relates to methods and systems for allowing a person, such as a finder of a valuable or other object, to communicate with the owner of the valuable or other object. BACKGROUND OF INVENTION [0003] All U.S. patents referred to herein are hereby incorporated by reference in their entireties. In the case of conflict, the present specification, including definitions, will control. [0004] For as long as there have been portable possessions, there have been opportunities to for them to be mislaid or go missing. When such possessions have intrinsic, subjective and/or sentimental value, the loss can be especially difficult for the owner of the possession. In today's society such possessions and objects might include a ring of keys, a portable music player with a large music collection, a laptop computer, a digital camera containing the only copy of treasured family photos, or any number of portable objects. [0005] One time-tested method of protecting against the permanent loss of an object is for the owner to write her name and contact information, for example, a phone number and an address, on the object or on a tag or label attached to the object. Then, when the object is lost or otherwise separated from its owner, a person finding the object can use the name and contact information to contact the owner and communicate arrangements for the return of the object to the object's owner. However, this approach has drawbacks. First, such an approach provides information about the owner's identity to an unknown person. If the lost object were a ring of keys, a finder with mal-intent could use the information on the tag to discern the identity and address of the owner and then use the keys to gain access to her residence. Second, such an approach may not provide contact information with the best currency—such as when the owner is traveling or has recently moved. If the information on the tag is not current and the finder cannot quickly communicate with the owner, an opportunity may be lost for the finder to return the object to the owner before the owner continues in her travels. [0006] Another method for tagging possessions to protect against their loss is referred to in U.S. Pat. No. 6,259,367 to Klein. This patent refers to the use of RFID tags encoded with “obfuscated” owner information. The RFID encoded information may be used to retrieve a file containing more detailed owner contact information. A drawback to Klein's approach is that a finder must gain access to an RFID tag reader and appropriate software to decode the information and access the file through a network. When this is done through a third party, either the third party must disclose the owner's private contact information or the finder must trust the third party to return the item to the owner. As with conventional tags, Klein's system may lack the most current contact information, create delays (and lost opportunities) in returning possessions, and result in the loss of owner privacy. [0007] Other systems purport to overcome these disadvantages but fall short. Some require the use of a shipping intermediary in order to return the object to its owner. Some require a third party intermediary to process a “found” report and provide return instructions to a finder. SUMMARY OF THE INVENTION [0008] The present invention overcomes the disadvantages of the prior systems by providing for a timely and anonymous communication channel between a finder of an object and an owner of an object. [0009] In accordance with one aspect of the invention, there is a method of facilitating communication between a finder of an article and an owner of the article which includes providing a unique ID to the owner, allowing the owner to register an association between the ID and owner contact information, allowing the owner to associate the ID and a virtual locale (for example, a website address) with the article, and forwarding communications of the finder of the article to the owner where the finder may have provided no more than the ID and the communication to the virtual locale. [0010] In accordance with another aspect of the invention, there is a system for facilitating communication between a finder of an article and an owner of the article which includes a virtual locale, a database for storing an association between owner contact information and a unique ID, and a module for forwarding finder communications to the owner where the finder provides as little information as the communication and the unique ID to the virtual locale. BRIEF DESCRIPTION OF THE DRAWINGS [0011] FIGS. 1A , 1 B, 1 E, 1 F, 1 G, 1 H, 1 I, 1 J, 1 K, 1 L, 1 M, 1 N, 10 , 1 P, 1 Q, 1 R, 1 S, 1 U, 1 V, 1 X, 1 Y, and 1 Z depict steps of a method in accordance with a preferred non-limiting embodiment of the invention; [0012] FIGS. 2A and 2B depict examples of tags with associated IDs and reference addresses that could be employed in accordance with embodiments of the invention; [0013] FIG. 3 depicts a main menu that could be employed in accordance with embodiments of the invention; [0014] FIG. 4 depicts an owner main menu that could be employed in accordance with embodiments of the invention; [0015] FIG. 5 depicts an ID registration screen that could be employed in accordance with embodiments of the invention. [0016] FIG. 6 depicts an open case screen that could be employed in accordance with embodiments of the invention; [0017] FIG. 7 depicts a new user screen that could be employed in accordance with embodiments of the invention; [0018] FIG. 8 depicts a contact information screen that could be employed in accordance with embodiments of the invention; [0019] FIG. 9 depicts a view/edit tag screen that could be employed in accordance with embodiments of the invention; [0020] FIG. 10 depicts a finder main menu that could be employed in accordance with embodiments of the invention; [0021] FIG. 11 depicts a send message menu that could be employed in accordance with embodiments of the invention; [0022] FIG. 12 depicts a short one way message entry screen that could be employed in accordance with embodiments of the invention; [0023] FIGS. 13A and 13B depict anonymously addressed e-mails that could be employed in accordance with embodiments of the invention; and [0024] FIG. 14 depicts an instant message that could be sent in accordance with an embodiment of the invention. DETAILED DESCRIPTION OF THE INVENTION [0025] In the following detailed description, reference is made to various specific embodiments in which the invention may be practiced. These embodiments are described with sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be employed, and that structural and logical changes may be made without departing from the spirit or scope of the present invention. [0026] The present invention provides systems and methods that allow a person, such as a finder of a lost or misplaced object, to anonymously communicate with another, such as the owner of the object. The systems and methods can be useful in facilitating the return of the object to its owner. [0027] In an aspect of the invention, an “owner,” which can be an individual or entity wishing to protect portable personal property, is provided with specially prepared tags. With reference to FIGS. 2A and 2B , such tags can be of any size or shape or type, such as a printed adhesive label 200 , a sew-on patch (not pictured), a plastic key-ring tag 250 with a hole for a key ring or keychain 230 , or even an electronic tag (e.g. an RFID) (not pictured). Two common features of the tags of the present invention are a unique identifying feature such as an ID (e.g., a string of alphanumeric characters) 210 and a reference to a specific website or other unique virtual locale (e.g., a text messaging number, an SMS number, or an instant messaging screenname) 220 . The ID 210 may be printed and/or electronically stored on or within the tag. As with the ID, the reference to the specific website or other virtual locale 220 may also be printed and/or electronically stored. [0028] As used in some of the figures, a tag is referred to as a zTag and an ID is referred to as a zID. [0029] In an embodiment, the owner would then affix tags 200 or 250 to any portable possession which she desires to be easily returned to her if lost or otherwise separated from her. Such objects and possessions might include an attaché case, a ring of keys, a portable music player with a large collection of music, a digital camera with irreplaceable family photos, a cell phone, and the like. [0030] Having been provided with tags and having affixed the tags to various possessions, the owner can then register the tag IDs and the owner's contact information on a centralized and network accessible database according to the present invention. [0031] With reference to FIG. 1A , a user, in this case, an owner, accesses a browser or client capable device, starting its operating system, ref. 1 , if necessary. Then the user navigates to the server, ref. 2 , using the browser or client capable device and receives a main menu, ref. 3 . [0032] With reference to FIGS. 3 and 1A , the server displays a menu 300 , ref. 4 , which in a preferred embodiment has a menu button for requesting the owner menu 310 , a menu button for requesting the finder menu 320 , and a data field for entering an ID of a found object 330 . [0033] In an exemplary embodiment, a user who is new to the system can select the option 340 “sign-up and register,” ref. 13 ( FIG. 1B ), from the main menu. When this option is selected, a data entry screen is displayed. With reference to FIG. 7 , the data entry screen may optionally be preceded by a “bot-killer” registration screen 700 , in which the user enters initial credentials such as an email address 710 and password 720 , and additionally enters a Verification Code in a field 730 , where the Verification Code 740 is displayed in a optically obfuscated manner so that an automated “bot” cannot register as a user. The registration screen may optionally include a consent to usage terms feature 750 . Following this optional bot-killer data entry screen, with reference to FIG. 8 , the screen 800 may include fields for adding and editing data such as the user's name 840 and various types of contact info, ref. 33 . Generally, in addition to a password, the only other required field is an unambiguous contact field entry, such as the user's email address 850 . If a user selects “save changes” or “add the new user,” ref. 34 , the entered data is validated, ref. 35 , and the new user is added to the database, ref. 37 . Then the main owner screen is displayed, ref. 7 ( FIG. 1B ). Should the entered email address already exist in the database, the user is alerted to the error, ref. 36 , and this procedure is restarted, ref. 33 . In a preferred embodiment, there is an option that the user can always select, ref. 38 , to return to the main owner menu, ref. 7 , without entering any information. [0034] When a user selects the owner option 310 , ref. 4 , the main owner menu 400 ( FIG. 4 ) is displayed, ref. 7 ( FIG. 1B ). The owner menu offers owner related choices, including going back to the Main Menu, ref. 8 . [0035] Should a user select Owner Log On, ref. 9 , an Owner Log On screen is displayed (not shown) and the user is prompted for their email address and password, ref. 62 ( FIG. 1K ). The system verifies these credentials against those in a database to determine whether they match a valid user, ref. 63 . If there is a match, a flag is set to indicate that the owner is logged on for this session, ref. 64 , and the owner's unique user id, herein userid, is placed in memory for future reference. If there is no match, an appropriate error message is displayed to the user, ref. 65 . Once these steps are completed, the main owner menu is displayed, ref. 7 ( FIG. 1B ). [0036] An owner wishing to associate an ID with his or her contact information must register the ID with the database. In an exemplary embodiment, the owner/user selects the “add a zTag” menu item 410 ( FIG. 4 ), ref. 10 , and is prompted, ref. 15 ( FIG. 1E ), with a screen 500 as shown in FIG. 5 containing fields for entry of the relevant information for that tag such as its ID 510 and a description 520 of the associated object or possession. However, before entering this part of the program, subroutine D is called to validate that the “owner logged on” flag is set to true, ref. 39 ( FIG. 1L ), and return, ref. 40 , to the calling step in the application if so, or display an appropriate message, ref. 41 , and return to the main owner menu, ref. 7 ( FIG. 1B ), if not. Once the user supplies the information and selects “add item” 530 , ref. 16 ( FIG. 1E ), the server confirms that the data is in the valid format, ref. 17 , and that the user has entered a valid and available ID, ref. 19 . Any error in this process is displayed to the user, ref. 18 and the screen 500 may be displayed, ref. 15 . If there are no errors, the database is updated with the tag information and the database record is associated with the user, ref. 20 . Control then passes to the main owner menu 500 , ref. 7 . There, the user may opt, ref. 21 , to return to the main owner menu, ref. 7 , without entering any information. [0037] In the illustrated embodiment, when an owner wishes to see open cases, where an open case is defined as an instance of an open line of communication with a finder of an owner's tagged item, they select the menu item “view open cases” 450 , ( FIG. 4 ), ref. 11 ( FIG. 1B ). Before displaying the view open cases screen, subroutine D is executed in a manner similar to that earlier described with regard to subroutine D. The database is then queried for any open cases where the user's userid is listed as the owner. Retrieved records are used to create a list 600 ( FIG. 6 ), which is displayed to the user, where each line is related to an open case, and includes information from that particular case. For example, a list of open cases might include an ID of a tagged object 610 and a description of the tagged object 625 . Links may be associated with each case-related line which enable a user to close the case 650 or communicate with the finder of that case 620 . There are numerous options throughout this menu, and its submenus, so that the user can always select an option, ref. 31 ( FIG. 1F ), to return to the main owner menu without entering any information. If a user selects “close case,” ref. 25 , the case is marked as closed in the database, ref. 26 , and the open case screen 600 is updated, ref. 22 . Should the user select to contact the finder of a particular case, ref. 27 , they are prompted and given a field to type their email message, ref. 28 . In one embodiment, a finder's anonymous email address is displayed with a reminder that the user can email the finder using their own email program. Once the user selects “send message,” ref. 29 , the finder's real email address is used (yet never displayed to the user) to send an email, ref. 30 . This part of the program is then directed to restart, ref. 22 . [0038] Existing users can choose to edit their account settings, ref. 12 . Before displaying the account settings editing screens, subroutine D is run in a manner similar to that already described with regard to subroutine D. The database is queried for information associated with this user through use of a userid. In one embodiment, the user information will be displayed in editable fields, ref. 45 . With reference to FIG. 8 , such fields may include fields for the user's name 810 , addresses, password 860 , Instant Message Handles 810 , 820 , and 830 , phone numbers, and so on. The user may select to return, ref. 50 , to the main owner menu, ref. 7 , without entering any information. If the user selects “save changes,” ref. 40 , the system confirms that the new data are valid, ref. 47 , and if so, saves the record to the database, ref. 48 . Then the main owner window, ref. 7 , is then displayed to the user. If the validation fails, an appropriate message may be displayed to the user, ref. 49 , and the edit account settings screen is displayed, ref. 45 . [0039] In an exemplary embodiment, a user who has tags already registered in the system may edit the data, ref. 14 , associated with them. Before entering this part of the program, subroutine D is executed in a manner similar to that previously described herein. Following verification of the “owner logged on” flag by subroutine D, the database is queried for all tags associated with a userid of the user, ref. 51 . With reference to FIGS. 1I and 9 , for each such tag in the database, an information line may be created, ref. 52 , containing the tag's associated information such as the tag ID 930 , the date it was registered, description 940 and so on. Also, two links may be created for each tag, the links respectively allowing a user to “edit” the information associated with the tag, or “delete” the associated tag record from the database. The list is then displayed 900 to the user, ref. 53 . There may also be included on this menu, ref. 60 , and its submenus, e.g., ref. 61 , an option for the user to select to return to the main owner menu, ref 7 , without entering any information. Should a user select a delete tag link 920 , ref. 54 , the tag record's description and owner userid are both cleared in the database, ref. 55 , making the ID available for later use. From this point, the list is refreshed beginning at ref. 51 . If a user opts to edit a tag 910 , ref. 57 , then an editable field may be displayed, ref. 58 , containing that tag's current description and operable to allow the user to edit the description in a manner similar to that depicted in FIG. 5 . Once the user chooses to save the new description, ref. 56 , the database entry for that tag is updated, ref. 59 . From this point, the list is refreshed beginning at ref. 51 . [0040] Thus far, discussion has been made of how an owner of a tagged object can access and utilize a system in accordance with the present invention in order to supply and/or manage at least contact information and tag IDs. Another aspect of the invention involves finders. A finder is someone who has found an object, most likely lost, with an attached tag such as the exemplary tags depicted in FIGS. 2A and 2B . Such tags direct a finder to, for example, a website or other virtual locale. [0041] In a preferred embodiment of the present invention, a tag attached to an object will direct a finder to access a website named thereon 220 . At such a website, the finder may select the finder option, ref. 5 , resulting in the display of the finder main menu, ref. 66 . The finder main menu provides selections related to finders. Additionally, the finder may opt to return to the main menu, ref. 67 . [0042] According to one embodiment of the invention, a finder who is new to the system can select the option “new user,” ref. 70 . The program then creates and displays editable fields which may include fields for the user's name and various types of contact information, ref. 100 ( FIG. 10 ). Required information may include a password and an unambiguous contact information such as an email address. If a user selects to “add the new user,” ref. 101 , the system makes sure that the supplied information is valid, ref. 102 , and then adds the new user data to the database, ref. 103 . At this point, the main finder window is displayed, ref. 66 ( FIG. 1J ). Should the email address already exist in the database, the user is alerted to the error, ref. 104 , and the display is refreshed, starting at ref. 100 . Additionally, there may be an option, ref. 105 , for the user to select to return to the main owner menu, ref. 66 , without entering any information. [0043] Should a user select “Finder Log On,” ref. 68 , they are prompted for credentials such as their email address and a password, ref. 73 ( FIG. 1M ). The database is then queried for a match to the entered credentials, ref. 74 . If a match is found, then a flag is set to indicate that the finder is logged on for this session, ref. 75 , and the finder's unique user id, herein userid, is placed in memory for future reference. If no match is found, an error message is displayed to let the user know that they are not logged on, ref. 76 . In either case, the main finder menu 1000 ( FIG. 10 ) is displayed, ref. 66 . [0044] With reference to FIG. 10 , in accordance with an exemplary embodiment of the present invention, when a finder wishes to see open cases, where an open case is defined as an instance of an open line of communication between a finder and an owner with regard to an owner's tag, the finder selects “view open cases” 1010 , ref. 69 . Before displaying open cases, however, subroutine L, as shown in FIG. 1L , is called. This subroutine checks that the finder logged on flag is set to true, ref. 42 , and returns control to the application at the point of call to this subroutine, ref. 43 . If it is not, a suitable message is displayed to the user, ref. 44 , and the main finder menu is displayed, ref. 66 . If subroutine L verified the finder logged on flag, then the database is queried for open cases, where a finder's userid is listed as the finder, ref. 77 ( FIG. 1N ). The retrieved data is used to create a list, ref. 78 , which is displayed to the user, ref. 79 . The list may contain one line for each open case associated with the userid. A line may include two links which, respectively, enable the user to close the case, or communicate with the owner of that case. There may be numerous options throughout this menu, and its submenus, including options, refs. 86 and 87 , to return to the main finder menu, ref. 66 , without entering any information. The user can close the case, ref. 80 , which marks it as closed in the database, ref. 81 , and then refreshes the list, starting at ref. 77 . Should the user select to contact the owner of a particular case, ref. 82 , a display is created with a data entry field in which the user may enter an email message for the associated owner, ref. 83 . In a preferred embodiment, the display includes an anonymous email address, created in accordance with the invention, which corresponds to the owner's actual email address. The display also includes a reminder to the finder that they may optionally use the anonymous email address to contact the owner using the finder's own email software. Once the user selects “send message,” ref. 84 , the message is sent to the owner's real email address, ref. 85 . That email address is never displayed to the finder. The display is then refreshed with the open case list by beginning again at ref. 77 . [0045] Existing users can chose to edit their account settings 1020 , ref. 72 . Before displaying the edit account settings screen, subroutine L ( FIG. 1L ) is called to validate that the finder logged on flag is set to true in a manner similar to that already described with regard to subroutine L. If the logged on flag is properly validated by subroutine L, the database is queried using the previously stored userid for information associated with this user's account settings such as name, addresses, password, email address, and so on. This information is displayed to the user in editable fields, allowing the user to make changes, ref. 115 ( FIG. 1Q ). Preferably, there is an option that the user may select, ref. 120 , to return to the main finder menu, ref 66 , without entering or saving any information. Once the user selects save changes, ref. 116 , the system confirms that the data are valid, ref. 117 , and if so, saves the changes to the database, ref 118 , and displays the main finder window, ref. 66 . If invalid data were found, appropriate error messages are displayed to the user, ref. 119 , and the display is refreshed from ref. 115 . [0046] In one embodiment a user may choose to search for an ID number, ref. 71 . With reference to FIG. 11 , upon such a selection, a display 1100 containing a blank field 1110 will prompt the user to enter a search ID number, ref. 106 . Preferably, there are options on this menu (not shown in FIG. 11 ), ref. 114 , and its submenus, ref. 113 , allowing a user to select to return to the main finder menu, ref. 66 , without entering any information. Should the user enter an ID and click find, ref. 107 , the database is queried to see if the ID is valid and in use, ref. 108 . In one embodiment of the invention, entry to this part of the program, ref. 108 , may also occur from the main menu, where an ID field may exist for fast access to the search function. Should the ID not be a valid number for any reason, then the user is alerted, ref. 109 , and the finder menu, ref. 66 , is displayed. If the ID is valid, the description associated with it is shown, ref. 110 , to the user. In a preferred embodiment, two new choices may be displayed, allowing the finder to send a quick one-way anonymous message to the owner or to open up a new case and communicate using anonymous emails addresses. [0047] With reference to FIG. 12 , if the finder chooses to send a quick one-way message, ref. 111 , the user is then prompted to enter an email message into a provided field 1210 , ref. 129 . Optional text on the display may advise the finder that the quick one-way message is indeed one-way and that the owner will not be able to reply to the finder/sender. Preferably, there is an option, ref. 134 , to return to the main finder menu, ref. 66 , without entering any information. Once the user selects “send message,” ref. 130 , the message is directed to the real email address of the owner associated with the entered ID, ref. 131 . The owner's real email address is used but never displayed to the finder. If the owner has any other contact information entered, ref. 132 , for example, Instant Message handles, then the message is also sent out via those systems, ref. 133 . The program then returns to the finder menu, ref. 66 . [0048] In one embodiment, a finder may choose to open a new case, ref. 112 , for a tag ID associated with a found object. Prior to displaying a new case screen, subroutine L ( FIG. 1L ) is executed to validate the user logged on flag in a manner previously described for subroutine L. A new database record is created for this case, ref. 121 , and two anonymous email addresses are generated. In an exemplary embodiment, one email address begins with “Owner-,” ref. 122 , and the other with “Finder-,” ref. 123 . The generated email addresses may include a domain associated with the virtual locale. As an example, if the case involves ID 277899028 and the virtual locale is associated with www.zReturn.com, then the generated addresses could be Owner-277899028@zReturn.com and Finder-277899028@zReturn.com. The real email addresses for both the finder and the owner may be stored in the case record, ref. 124 . The finder is then provided a data entry field and prompted to type a message to the owner, ref. 125 . Optionally, the owner's anonymous email address may be displayed to the finder with a reminder that the finder may email the owner using the finder's own email program. Once the user selects “send email,” ref. 126 , the message in the data entry field is directed to the owner's real email address, ref. 127 , and; the real email address is never displayed to the user. The program can then return to the finder menu, ref. 66 . Preferably, there is an option, ref. 128 , on the new case screen allowing a user to return to the main finder menu, ref. 66 , without entering any information. [0049] With reference to FIG. 1Z , in a preferred embodiment, a server periodically executes a program to check for incoming email, ref. 88 , being delivered to a domain associated with the virtual locale. If there are no emails, the program halts, ref. 89 a . If an email has arrived, its “To” email address is checked for “Owner-,” ref. 90 , “Finder-,” ref. 91 , and “Alert-,” ref 91 a , to determine whether the email is addressed with an anonymized email address. If not, then the email is forwarded to any other account setup for internal use on the server, ref. 92 , and the program continues checking for new emails, ref. 88 . If the “To” email address begins with “Alert-”, then the email is passed off to the server application that handles the Multi-protocol Messaging Translator, ref. 165 ( FIG. 1X ). Otherwise, a case number associated with the “To” email address is determined and the database is queried for a record of an associated open case, ref 93 . If no such record exists, ref. 94 , then an auto-generated reply is sent to the sending email address, ref. 98 , explaining that no such record exists, and the program starts checking for new emails, ref. 88 , again. If a record does exist, the “From” email address is checked versus the email address contained in the record, ref. 95 . If the “From” email address is not the same as the record, then a reply is sent to the sender explaining that anonymous emails must be sent from the same email address registered in the case record, ref. 99 , and the program starts checking for new emails, ref. 88 , again. With reference to examples in FIGS. 13A and 13B , once email addresses have been confirmed, then the “To” anonymous email address 1320 is swapped with a real email address 1340 as per the record and the real “From” email address 1310 is replaced with an anonymous address 1330 from the record, ref. 96 . Then, the email is forwarded to the new “To” email address, ref. 97 . The receiving user's id record is checked for associated alert contact information such as AOL Instant Messenger, Yahoo Messenger, and/or Microsoft Messenger Handles and/or a cell phone text messaging address. For any of those that the user provided, the email is also forwarded to those systems, refs. 166 , 167 , 168 , 169 , 170 , 171 , 172 , 173 , and 174 ( FIG. 1Y ). Then the program starts checking for new emails, ref. 88 , again. [0050] With reference to FIG. 1X , in one embodiment, a program run by a server checks periodically for incoming messages from multiple messaging protocols such as AOL, Yahoo, and MSN Text Messaging, ref. 135 . If there are no incoming messages, ref. 136 , the program halts, ref. 137 . If there is a message, the first word of the message is isolated, ref. 138 , and checked against the database to see if it is a valid ID. If it is not a valid ID, or there is only one word in the message, then a simple instruction message, such as “How to properly use the system” is sent back as a reply to the sender, ref. 139 , and the program goes to check for other new messages. [0051] If the ID is valid, the messaging screenname that sent this message is checked, ref 140 , against all forms of messaging names and protocols associated with the owner who registered the ID number contained in the message. If it is determined that this message came from the owner of the ID to which the message refers, then control is passed over to ref. 161 . If none of the owner associated names and protocols match the sender of the message, then a messaging database is queried to match up the ID and the message's screenname and protocol, ref 141 . If no record is found, then a record is created, linking the ID, the screenname, and the protocol, refs. 142 , 143 , and 144 . [0052] Continuing with the exemplary embodiment for handling inbound Instant Messages, the inbound message will be directed to the owner's designated IM addresses. With reference to FIG. 14 , for each existing form of alert that the owner registered, e.g. AOL, MSN, Yahoo, cell phone text messaging, and so on, the software will make a new message that may optionally include an introduction concerning the nature of the message 1410 and how to properly reply to it. The message will include the message sent by the sender 1420 . The message will be sent to each of these messaging options registered by the owner, refs. 145 , 146 , 147 , 148 , 149 , 150 , 151 , 152 , 153 , 154 , 155 , 156 , 157 , and 158 ( FIG. 1U ). A new message, as described above, may optionally be sent to the owner's email address. The “From” email address may be of a form similar to “Alert-XXX@zReturn.com,” where XXX is the ID number. The software application then looks for more incoming messages, ref. 135 ( FIG. 1X ). [0053] Finally, if it is determined that the inbound message originated from an owner of an ID to which the inbound message refers, then the application looks in the alert database for the record created by the sender of the original message, refs. 141 , 142 , 143 , and 144 . If no record can be found the application halts, refs. 161 , 161 a . Otherwise, the screenname and protocol are pulled from the found record, and a new message is created which may optionally include an introduction on what this message is, and how to properly reply to it. The message includes the message sent by the sender. The new message is then sent to the screenname and platform from the record in the alert database, refs. 161 b , 162 , 163 , and the program continues to look for more messages, ref. 135 . [0054] The foregoing disclosure of the preferred embodiments of the present invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many variations and modifications of the embodiments described herein will be obvious to one of ordinary skill in the art given the above disclosure. The scope of the invention is to be defined only by the claims appended hereto, and by their equivalents. [0055] Further, in describing representative embodiments of the present invention, the specification may have presented the method and/or process of the present invention as a particular sequence of steps. However, to the extent that the method or process does not rely on the particular order of steps set forth herein, the method or process should not be limited to the particular sequence of steps described. As one of ordinary skill in the art would appreciate, other sequences of steps may be possible. Therefore, the particular order of the steps set forth in the specification should not be construed as limitations on the claims. In addition, the claims directed to the method and/or process of the present invention should not be limited to the performance of their steps in the order written, and one skilled in the art can readily appreciate that the sequences may be varied and still remain within the spirit and scope of the present invention. [0056] Furthermore, a person skilled in the art will recognize that some aspects of the present invention, described with reference to a sequence of condition checks, may be easily implemented with an event driven code design. [0057] Aspects of the described system and method may be implemented in a programming language such as the Perl programming language in conjunction with the Apache open source web server software and the MySQL open source relational database running under the Linux operating system. Additionally, those of skill in the art are aware of open source modules available to aid in implementing aspects of the present invention. For example, the Perl module Net-Oscar is available from cpan.org and is operable to interface with instant messaging systems such as AOL instant messenger and ICQ. However, other programming languages, operating systems, and database systems are adaptable to the present invention and may also be used.

A method and system of facilitating communication between a finder of an article and an owner of the article including providing a unique ID to the owner and allowing the owner to register an association between the ID and owner contact information, allowing the owner to associate the ID and a virtual locale with the article, and forwarding communications of the finder of the article to the owner where the finder may provide no more information to the virtual locale than the ID and the communication.

big_patent

STATEMENT REGARDING FEDERAL RIGHTS This invention was made with government support under Contract No. W-7405-ENG-36 awarded by the U.S. Department of Energy. The government has certain rights in the invention. FIELD OF THE INVENTION The present invention relates generally to electron multipliers and, more particularly, to electron multipliers used in photomultipliers and particle detectors such as channel electron multipliers and microchannel plates that are used extensively in electron spectrometers, mass spectrometers, and photonic detectors. BACKGROUND OF THE INVENTION Two types of conventional electron multipliers are routinely used. A first type, pictorially illustrated in FIG. 1 , consists of discrete dynode multipliers, which comprise dynodes stages 10 that initiate and amplify a cascade of electrons. U.S. Pat. No. 4,668,890, issued May 26, 1987, details this type of electron multiplier. Typically, dynode stages 10 are biased using resistor divider string 20 such that front dynode 12 of the multiplier is biased to a high negative voltage (e.g., several kilovolts) relative to last dynode 14 and anode 16 of the multiplier. Thus, an electric field is imposed between each of the dynodes. As incoming particle 30 strikes the front dynode 12 it generates an average of γ I secondary electrons 32 from the impact surface of front dynode 12 . These secondary electrons are accelerated by the imposed electric field toward the next successive dynode, where they impact and generate more secondary electrons. This cascade of electrons continues throughout the entire series of dynode stages with the cumulative charge of the electron avalanche growing at each stage. After last dynode 14 , the electron avalanche charge is collected on anode 16 . The gain (G D ) of a discrete dynode multiplier, which equals the cumulative output electron charge per incident particle, corresponds to: G D =γ I γ SE N−1   (Equation 1) where γ SE equals average number of secondary electrons emitted by an electron from one dynode impacting on the next sequential dynode and N equals the number of dynodes used in the detector. To maximize the gain, the dynode material is often selected for high secondary electron emission yield (γ SE ) properties (See U.S. Pat. No. 5,680,008, issued Oct. 21, 1997). The second type of multiplier is a continuous electron multiplier, pictorially illustrated in FIG. 2 . Channel electron multipliers and microchannel plate (MPC) detectors are specific examples of this type. MPCs employ one or more high resistivity glass channels or tubes 40 , each of which acts as a series of continuous dynodes. Patented examples of this type of electron multiplier include: U.S. Pat. No. 4,095,132, issued Jun. 13, 1978; U.S. Pat. No. 4,073,989, issued Feb. 14, 1978; U.S. Pat. No. 5,086,248, issued Feb. 4, 1992; U.S. Pat. No. 6,015,588, issued Jan. 18, 2000; and U.S. Pat. No. 6,045,677, issued Apr. 4, 2000. As with the discrete dynode, channel front 42 is negatively biased several kilovolts relative to the channel back 44 and anode 50 , so that an electric field is imposed inside of the channel from the front (entrance) to the rear (exit). Incident particle 60 impacts channel front 42 and generates secondary electrons 62 , which are then accelerated further into tube 40 by the imposed electric field. Secondary electrons 62 impact channel wall 41 and generate even more secondary electrons. The cumulative charge of the electron avalanche grows as it traverses tube 40 . The avalanche of secondary electrons 62 exits tube 40 , and is collected on anode 70 . The gain of a continuous electron multiplier can be modeled as a series of discrete dynodes and can therefore be represented by Equation 1. A variation of this concept uses a porous media having irregular channels; e.g., U.S. Pat. No. 6,455,987, issued Sep. 24, 2002. A foil electron multiplier, in accordance with the present invention, encompasses the next generation design of electron multipliers. In a preferred embodiment, a series of extremely thin, in-line foils are used to create secondary electrons. The in-line orientation of the foils coupled with their thinness not only creates secondary electrons, but allows the incident primary particles, and the secondary electrons generated by the primary particles, to continue to the next and subsequent foils. It is believed that this design not only creates a larger avalanche of electrons when compared to historical designs, but also allows for obtaining position-sensitive information on where an incident particle impacted the first stage of the foil electron multiplier. The ability to provide position-sensitive information enables improvements on articles such as flat television screens, computer screens, night vision devices, and the like. Advantages of the foil electron multiplier design over other types of electron multipliers include: (1) A higher gain per multiplication stage that results in an increased multiplication efficiency since fewer stages are required to obtain the same charge as other multipliers. (2) Simplicity of fabrication, since the foil fabrication process (evaporation of a foil material onto a glass slide covered with a surfactant and a subsequent aqueous transfer to a support grid or aperture plate) is simpler than fabrication of continuous multipliers, such as MCPs. The MCP fabrication process requires high purity materials, high precision, a high level of cleanliness, and involves using cladded fibers that must be bundled, stretched, and sintered in cycles, and then cut, etched, and chemically activated. (3) A lower cost of fabrication, as the fabrication process complexity is reflected in the relevant cost. Twenty commercial foils cost about $500 whereas MCP detectors cost about $5,000 to $10,000. (4) An ability to cover a larger area, as foils can be evaporated over large surface areas, whereas MCPs require additional bundling and sintering to increase the surface area. Also, large area foils are much more robust as they can be dropped without breaking, whereas MCPs shatter. (5) Finally, the foil electron multiplier exhibits an intrinsic rejection of ion feedback at each stage. Continuous electron multipliers require a curved or zigzag path to prevent ions from being accelerated back toward the entrance where they can initiate a second pulse. In the foil electron multiplier, ions generated at one foil may be accelerated back to the previous foil, but cannot be re-transmitted back because the ion energy is too low. Therefore, ions can only reach one stage back, and a pulse that they generate will be indistinguishable from the main pulse. Additional objects, advantages and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims. SUMMARY OF THE INVENTION In accordance with the purposes of the present invention, as embodied and broadly described herein, the present invention includes an apparatus for electron multiplication by transmission that is designed with at least one foil having a front side for receiving incident particles and a back side for transmitting secondary electrons that are produced from the incident particles transiting through the foil. The foil thickness enables the incident particles to travel through the foil and continue on to an anode or to a next foil in series with the first. The foil, or foils, and anode are contained within a supporting structure that is attached within an evacuated enclosure. An electrical power supply is connected to the foil, or foils, and the anode to provide an electrical field gradient effective to accelerate negatively charged incident particles and the generated secondary electrons through the foil, or foils, to the anode for collection. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and form a part of the specification, illustrate the embodiments of the present invention and, together with the description, serve to explain the principles of the invention. In the drawings: FIG. 1 is a pictorial illustration of a prior art discrete dynode electron multiplier FIG. 2 is a pictorial illustration of a prior art continuous dynode electron multiplier FIGS. 3 a and 3 b are pictorial illustrations of embodiments of the present invention foil electron multiplier. FIGS. 4 a and 4 b , a cross-sectional view and face view, respectively, of one embodiment of foil, grid, and foil holder. FIG. 5 graphically shows the gain produced with a foil electron multiplier having 2, 3, and 4 foil stages as a function of the applied voltage-per-stage. FIG. 6 graphically shows the gain of a foil electron multiplier at an applied voltage-per-stage in the range of −650 V to −750 V. DETAILED DESCRIPTION A foil electron multiplier, in accordance with the present invention, uses a sequential series of thin foils in an evacuated enclosure that act to multiply electrons in a series of transmission stages. A voltage is applied to each foil to accelerate electrons emitted from the back of one foil to an energy level that effectively transmits the electrons through the next foil in the series, as well as generating secondary electrons that add on to the transmitted electrons and continue on to the next foil in the series. Thus, the present invention may be used for amplification of an incident electron flux or for detection of particles (e.g., photons, ions, electrons, and the like). Therefore, the present invention may be used in photomultiplier tubes and particle detectors, such as channel electron multipliers and microchannel plates. Channel electron multipliers and microchannel plates are used extensively in electron spectrometers, mass spectrometers, and photonic detectors, such as night vision devices. Referring to FIGS. 3 a and 3 b , the foil electron multiplier comprises a series of thin foils 100 held by foil holders 105 in an evacuated enclosure 110 that form discrete multiplication stages. In a preferred embodiment, foils 100 are arranged collinearly, although it will be understood that foils 100 can be arranged in an array that is along an arc as shown in FIG. 3 b . Voltage 120 is applied to each foil 100 , so that secondary electrons 155 created by incident particle 150 are accelerated in a direction from first stage 102 of the multiplier through last stage 108 and collected onto anode 130 . The voltage on each stage can be applied, for example, by attaching electrical resistors 140 between adjacent stages to form a resistor divider string across the multiplier, or by attaching separate power supplies (not shown) to each stage. This results in an electric field having a positive gradient between adjacent foils that accelerates secondary electrons between successive stages in the multiplier. If the foil electron multiplier is used in photomultiplier device, the anode could, for example, be a made from a scintillator material that converts electron energy to light. When using the foil electron multiplier as a detector, the anode is electrically connected to sensing electronics that measure the output charge or current deposited onto the anode. For example, a pulse of electrons resulting from a single particle that is incident on the foil multiplier can be directed into an electronic amplifier, whereupon the amplified pulse can be measured using detection electronics. As another example, an ammeter can measure the amplified current of a particle flux incident on the foil electron multiplier. Since the foil electron multiplier can span a large active area, a position-sensitive anode could provide position-sensitive information on where an incident particle impacted a stage of the foil electron multiplier. Foil electron multipliers, as shown in FIGS. 3 a and 3 b , are defined as having N foils and a resistor divider between each foil with an applied voltage V APP , for N>1, such that the potential between individual stages is V S =V APP /(N−1). An incident particle (electron, ion, or photon) transits through the first foil and generates an average of γ I secondary electrons at the rear surface. The secondary electrons are then accelerated by the voltage V S between the first and second stages toward the second foil and are transmitted with a probability T SE through the second foil, where T SE depends on the foil thickness τ and accelerating potential V S . If an electron from the first stage successfully transits through the second foil and exits at an energy E, it will generate a second set of electrons at an average secondary electron emission yield equal to γ SE , where γ SE is a function of E, and, therefore, a function of foil thickness τ and accelerating potential V S . This electron multiplication process continues at each foil stage, resulting in a growing avalanche of electrons, which are finally deposited onto the anode. The mean gain, G N , of the foil electron multiplier with N stages resulting from impact of a particle with the first stage is: G N =T I T G γ I [T SE T G [γ SE +1]] N−1   (Equation 2) where T I is the probability of incident particle transmission through the first foil. Often, the foil can be thin enough to require a supporting grid for structural integrity, and T G equals the transmission through such a grid of a single stage. The term T I T GγI corresponds to the mean number of secondary electrons generated at the first stage by the incident particle. The term T SE T G corresponds to the probability that a secondary electron successfully transits the second or subsequent stage, and the term (γ SE +1) corresponds to the mean number of secondary electrons exiting the second or subsequent stage. Generally, the gain of a foil electron multiplier is maximized by: 1) maximizing the electron transmission T SE of electrons through the foil by operating at an applied bias V S such that the imposed electric field accelerates electrons to an energy level sufficient to allow the electrons to transit through the foil; 2) maximizing the transmission through the support grid T G by selecting a grid that provides required structural support but maximizes the grid open area; and 3) maximizing γ SE by optimizing the voltage per stage V S such that electrons transmitted through a foil exit the foil at an optimal energy for high secondary electron emission yield and by selection of a foil material having high secondary electron emission yield. A preferred embodiment uses as thin of a foil as possible to minimize the required stage bias V S for electrons to transit a foil. However, a trade-off exists since an extremely thin foil may require a grid for structural support, which results in T G <1 and therefore a reduced gain. Electrons are negatively charged as they traverse the foil electron multiplier. However, the charge on incident ions may change, because ions can exit a foil with a positive, neutral, or negative charge. If an incident particle exits a stage negatively-charged, the particle is accelerated by the imposed electric field to the next stage similar to an electron. If an incident particle exits a stage positively-charged, the particle will be decelerated by the imposed electric field, and may not transit the foil of the next stage absent sufficient momentum. For the case of a negatively charged ion, positively charged ion with sufficient momentum, or electron incident on the foil electron multiplier, the ion or electron can transit several or all of the foils, initiating a new electron avalanche at each foil. The pulse of electrons deposited onto the anode therefore consists of all of the avalanches initiated by the ion or electron at each foil. Mathematically, the average total gain for incident particles that can transit all foils in the multiplier (T I =1) and can generate secondary electrons at each stage is represented by: G = ∑ n = 0 N - 1 ⁢ T G n ⁢ G N - n ( Equation ⁢   ⁢ 3 ) where T G n equals the probability that the incident particle transits all grids before stage N−n. Therefore, Equation 2 can be rewritten as: G = T G N ⁢ T I ⁢ γ I ⁢ ∑ n = 0 N - 1 ⁢ ( T SE ⁡ ( γ SE + 1 ) ) n ( Equation ⁢   ⁢ 4 ) Equation 4 represents a series of N terms of increasing magnitude corresponding to additional stages of multiplication, such that each term increases by a factor equal to T SE (γ SE +1) relative to its previous term. For the limiting case in which the incident particle impacts only the first stage (n=N−1 only), Equation 4 reduces to Equation 2. The gain advantage of the foil electron multiplier, which utilizes secondary electrons emitted from the rear surface of a foil, over conventional multipliers, which utilize secondary electrons emitted from the same surface that an incident electron impacts, lies in the term γ SE +1. First, the secondary electron yield from a primary electron exiting a foil typically should be greater than the secondary electron yield from a primary electron entering a surface, similar to ions transmitted through foils. Therefore, γ SE for a foil electron multiplier is likely to be larger than the secondary electron yield for a conventional electron multiplier. Second, a primary electron that generates secondary electrons at the exit surface of a foil stage also continues to the next stage with the secondary electrons that it generated. The continuation of the primary electron with the secondaries that it produces is represented as “+1” in the term γ SE +1 in Equation 4. This contrasts with conventional electron multipliers in which electrons that impact a dynode are typically absorbed in the dynode material and cannot contribute to further gain in the multiplier. Ion feedback in electron multipliers, which is important primarily for continuous electron multipliers, results when an ion is created by the electron avalanche and the ion is accelerated in a direction opposite to that of the propagation direction of the electron avalanche due to the imposed electric field. The ion traverses a significant distance of the channel length toward the entrance end of the channel, impacts the channel wall, and initiates another electron avalanche. This results in two avalanches that collectively are observed at the anode as two individual pulses or a single pulse that is temporally long, both of which are generally not desired when the multiplier is used as a particle detector. This limitation can be resolved using curved channels such that an ion generated in a channel cannot travel far within the channel before it impacts the wall of the channel, so that the resulting ion-induced avalanche is nearly indistinguishable in time from the initial electron avalanche. The present invention does not experience ion feedback. In the electron foil multiplier, ions generated at the input surface of a particular stage are accelerated toward the previous stage, but cannot penetrate the foil. These ions can initiate another avalanche, but this avalanche is generally indistinguishable in time from the initial avalanche. Foil Electron Multiplier Design The range of foil dimensions practiced for the present invention is from about 0.5 cm diameter (round) to 2×4 cm 2 (rectangular); although this range may be expanded or reduced depending on the application sought. In a preferred embodiment a round 1 cm diameter foil is used. The foil areal thickness can range from about 0.2 μg/cm 2 to about 2 μg/cm 2 . In a preferred embodiment the range is 0.2 to 1 μg/cm 2 . Foil dimension and thickness characteristics are directly related to the material selected for foil composition. Using currently available commercial foils, such as those provided by ACF Metals, carbon provides the thinnest and most uniform foils; therefore, carbon is the preferred foil material. However, other materials can also be used, to include: silver, gold, chromium, and hydrocarbons such as Lexan®, and the like. There is a trade-off between foil thickness and applied voltage: the thinner the foil, the lower the voltage required for the secondary electrons to transit the subsequent foil. In a preferred embodiment, an applied voltage of about −650 V per stage was found to be optimal for a 0.6 μg/cm 2 carbon foil. A thinner foil would require a lower applied voltage. The distance between foil stages is minimized to save volume, but must be large enough to withstand the applied voltage (i.e. no arcing between adjacent foil stages). A typical, conservative design for high voltage standoff is 1 mm per kV. At the preferred foil areal thickness (0.2 to 1 μg/cm 2 ) it is not currently possible to span a commercial foil across an aperture without a supporting grid. Thus, a support grid attached to the foil holder and spanning the aperture is required. FIG. 4 displays a preferred embodiment of foil 100 , grid 103 , and foil holder 105 . The foil holder and grid, if required, may be made from any conductive material, such as metals or metal alloys, or semiconductors, or insulators with a finite resistance. Grid 103 may be attached to foil holder 105 by spot welding or may be designed as an integral part of foil holder 105 by using a standard lithography process to etch the grid windows into a sheet of foil holder 105 material. An exemplary embodiment of a support grid is a conductive frame with an attached 200 line-per-inch nickel grid. For a self-supporting foil, the foil would need to be thicker and, therefore, the applied voltage per stage would need to be higher. However, as commercial fabrication techniques continue to improve, it may be possible to procure very thin, self-supporting foils. Since a beam of energetic ions transmitted through a thin foil will scatter, and the magnitude of angular scattering increases with increasing foil thickness, measurement of the angular scattering distribution of a narrow beam of ions provides a simple and accurate method to estimate of the foil thickness. The foil electron multiplier was demonstrated using nominal 0.6 μg/cm 2 areal thickness carbon foils that are typically measured using angular scatter distributions of keV H + that relate approximately to a 1.5 μg/cm 2 areal thickness. A foil stage consisted of a conductive frame having a 5-mm-diameter aperture on which was attached a 200 line-per-inch nickel grid, which was used for structural support of the foil and had a transmission of approximately 78%. The commercially available grid was procured from Buckbee-Mears, Inc. A nominal 0.6 μg/cm 2 areal thickness carbon foil was affixed to the grid. As shown in FIG. 3 a , the foil electron multiplier was constructed using a series of foil stages 100 followed by conductive anode 130 . Foil stages 100 were aligned in evacuated chamber 110 such that their apertures were collinear. Foil stages 100 were separated by a dielectric material (not shown) such that the spacing between adjacent foil stages was 5-mm. Anode 130 , which consisted of a conductive aluminum plate behind last stage 108 , collected electrons transmitted through and generated at last stage 108 . Resistors 140 having a resistivity value of 450 MΩ were attached between adjacent foil stages and between last stage 108 and anode 130 . Note that the value of resistor 140 between last stage 108 and anode 130 can be much lower without change in detector performance, because the imposed electric field between last stage 108 and anode 130 is only used to direct the electrons from the exit of last stage 108 to anode 130 . However, a resistor equal in value to the other resistors in the resistor divider string was chosen for simplicity of calculating the voltage applied per stage. The input end of the multiplier was biased to a negative bias V APP 120 of 650 volts, and referenced to ground. Anode 130 was connected to an ammeter (not shown) that measured the output current of the multiplier. In an evacuated chamber, a 2.7-mm-diameter 50 keV O + ion beam was first directed into a Faraday cup apparatus to measure the incident O + beam current I IN , and then directed into the input end of the foil electron multiplier. The output current I OUT from the foil electron multiplier was measured as a function of the applied voltage V APP . This was performed for foil electron multipliers configurations having 2, 3, and 4 foil stages. The multiplier gain, which is defined as the ratio I OUT /I IN , is shown in FIG. 5 as a function of the applied voltage V APP for the multiplier configurations. As the applied voltage is increased, the multiplier gain increases to a maximum at an applied voltage of approximately 650 V per stage. This voltage corresponds to an energy sufficient for secondary electrons to transit a foil and exit with an energy at which they can efficiently generate secondary electrons at the exit surface. At V APP =0 V, only electrons generated at the exit surface of the last foil from incident O + that transits the last foil are measured, and the decrease in the gain for an increasing number of stages results from attenuation of the incident O + beam by the structural support grid in each stage. FIG. 6 shows the maximum gain, that occurs at a voltage per stage of V S =V APP /N≈−650 V as a function of the number N of stages. On a semi-log plot, the data generally follow a straight line that infers a gain behavior described by Equations 1 through 4. The data was fit to Equation 4 using, for simplicity, the largest two terms n=N−1 and n=N−2 in the fitted equation. For T G =0.78, the fit resulted in T IγI =3.83 and T SE (γ SE +1)=1.88, which is shown as the solid line in FIG. 5 . The fit agreed well with the data, and the gain per stage T SE (γ SE +1)=1.88 is higher than the equivalent gain-per-stage equal to ˜1.37 of a microchannel plate detector. This higher gain per stage results in fewer required stages in a foil electron multiplier than a conventional electron multiplier. These results demonstrate that the foil electron multiplier performs as described in Equations 1-4 and that a foil electron multiplier has a higher gain efficiency than conventional electron multipliers. The foregoing description of the invention has been presented for purposes of illustration and description and is not intended to be exhaustive or to limit the invention to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application to thereby enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto.

An apparatus for electron multiplication by transmission that is designed with at least one foil having a front side for receiving incident particles and a back side for transmitting secondary electrons that are produced from the incident particles transiting through the foil. The foil thickness enables the incident particles to travel through the foil and continue on to an anode or to a next foil in series with the first foil. The foil, or foils, and anode are contained within a supporting structure that is attached within an evacuated enclosure. An electrical power supply is connected to the foil, or foils, and the anode to provide an electrical field gradient effective to accelerate negatively charged incident particles and the generated secondary electrons through the foil, or foils, to the anode for collection.

big_patent

RELATED APPLICATION DATA [0001] This application claims priority of U.S. Provisional Application No. 60/664,369 filed on Mar. 23, 2005, and is a continuation-in-part of application Ser. No. 10/054,607 filed on Jan. 22, 2002, that also claims priority of U.S. Provisional Application No. 60/263,498 filed on Jan. 23, 2001 with the entire contents of each application being herein incorporated by reference. TECHNICAL FIELD [0002] This invention relates to the field of motion pictures, and more specifically to a system that will allow almost any motion picture to be viewed effortlessly by the viewer with the visual effect of 3-dimensions. PRIOR ART REFERENCES [0003] A number of products and methods have been developed for producing 3-D images from two-dimensional images. Steenblik in U.S. Pat. Nos. 4,597,634, 4,717,239, and 5,002,364 teaches the use of diffractive optical elements with double prisms, one prism being made of a low-dispersion prism and the second prism being made of a high-dispersion prism. Takahaski, et al in U.S. Pat. No. 5,144,344 teaches the use of spectacles based on the Pulfrich effect with light filtering lens of different optical densities. Beard in U.S. Pat. No. 4,705,371 teaches the use of gradients of optical densities in going from the center to the periphery of a lens. Hirano in U.S. Pat. No. 4,429,951 teaches the use of spectacles with lenses that can rotate about a vertical axis to create stereoscopic effects. Laden in U.S. Pat. No. 4,049,339 teaches the use of spectacles with opaque temples and an opaque rectangular frame, except for triangular shaped lenses positioned in the frame adjacent to a nosepiece. [0004] Davino, U.S. Pat. No. 6,598,968, ‘3-Dimensional Movie and Television Viewer’, teaches an opaque frame that can be placed in front of a user's eyes like a pair of glasses for 3-D viewing to take advantage of the Pulfrich effect. The frame has two rectangular apertures. These apertures are spaced to be in directly in front of the user's eyes. One aperture is empty; the other opening has plural vertical strips, preferably two, made of polyester film. Between the outer edge of the aperture and the outermost vertical strip is diffractive optical material. The surface of the strips facing away from the person's face might be painted black. Images from a television set or a movie screen appear three dimensional when viewed through the frame with both eyes open. [0005] Synchronization and Control [0006] The 3-D Phenomenoscope invention makes use of signals to synchronize the lens filters to the lateral motion in the motion picture, and thus control the 3-dimensional visual effect for the viewer. The signals are developed in real-time by the 3-D Phenomenoscope, and does not require any alteration to the motion picture, or that any control information is placed in the motion picture. The information that is calculated is used to determine synchronization events that are used to control individually, the state of darkening of the lenses of the 3-D Phenomenoscope. [0007] Motion pictures have benefited from other types of synchronization and control information that is placed within the frames of motion pictures. However, these are characteristically different than the synchronization and control used in this invention. [0008] In many motion pictures, to alert the movie theater projectionist that it is time to change reels, movie producers would place visible control information, in the form of a white circle appearing in the upper right upper hand corner of successive frames of the movie. When the projectionist sees this information, they know that it is time to start a second projector that has the next reel of the movie, and thus maintain an uninterrupted motion picture presentation. [0009] Another means of communicating control information in motion picture frames is with the clapper slate board that indicates the start of a new scene when filming a motion picture. When filming motion picture or other type of video production, video and audio have been recorded separately. The two separate recordings must be precisely synchronized to insure that the audio recording matches the video image. Synchronization of the video and audio recordings has been accomplished using a clapper slate board. The audible clap created when a technician snaps the slate board in front of the camera is used during editing to manually synchronize the audio recording with the video recording. The editor simply views the video image of the snapping clapper slate, and then manually adjusts the timing of the audio recording such that the image of the clapper snapping shut and the sound of the clapper snapping shut are synchronized. Such synchronization can now be accomplished using electronic clapper slates. Electronic clapper slates display a Society of Motion Picture and Television Engineers (SMPTE) code, usually in large red light emitting diode numerals. The SMPTE code displayed is then used to electronically synchronize the video recording with a separate audio recording. [0010] These types of synchronization and control information solve problems related to the synchronization of sound with filmed action during the production and editing of motion pictures, and related to changing reels of film during the presentation of motion pictures. [0011] The preferred embodiment of the 3D Phenomenoscope uses a computer algorithm running on a computer processor contained within the 3-D Phenomenoscope to calculate in real-time, and from a multiplicity of media frames, the synchronization and control events. The preferred embodiment has no moving parts and no wire connections, and uses material that partially occludes or entirely clears in response to the received electronic signals. The 3D Phenomenoscope has a means to receive, and process the video of the motion picture, and control the left and right lenses. In this way, the 3-D Phenomenoscope allows any motion picture with a degree of sustained lateral motion (for instance, every ‘chase’ sequence) to be viewed with the visual effect of 3-dimensions. [0012] The 3-dimensional visual effect is produced by the 3-D Phenomenoscope regardless of whether the motion picture was shot on regular or digital film; regardless of whether the presentation media is film, digital film, VCR tape, or DVD, and; regardless of whether the motion picture is viewed in the movie theater, home TV, Cable TV, or on a PC monitor. BACKGROUND OF THE INVENTION [0013] Visual effects have the potential to expand the viewing enjoyment of moviegoers. For example the movement effect ‘Bullet Time’ utilized in the movie ‘The Matrix’ was critical to the appeal of the movie. [0014] Visual effects for 3-dimensional motion pictures have been used commercially since the early 1950s, and include such motion pictures as ‘Charge at Feather River’, starring Guy Madison. The ‘Vincent Price movie ‘House of Wax’ was originally released as a 3-D thriller. The 3-D movie fad of the early to mid-1950s however soon faded due to complexity of the technologies and potential for improper synchronization, and alignment of left and right eye images as delivered to the viewer. [0015] TV 3-D motion pictures have been attempted from time-to-time. Theatric Support produced the first TV Pulfrich event in 1989 for Fox Television—The Rose Parade in 3D “Live.” In order to sustain the illusion of realistic depth these 3-D Pulfrich effect TV shows require all foreground screen action to move in one consistent direction, matched to the fixed light-diminishing lens of special spectacles provided to viewers for each broadcast. This enormous constraint (for all screen action to proceed in one direction) placed on the producers of the motion picture is due to the realistic expectation that viewers were not going to invert their spectacles so as to switch the light-diminishing filter from one eye to another for each change in screen-action direction. For the great majority of viewers the limitation of spectacles with a fixed filter, either left or right, meant the 3D effect would be available only with movies produced specifically for that viewing spectacles design. [0016] With the exception of Sony I-max 3-D presentations, which require special theater/screening facilities unique to the requirements of 1-Max technology, 3-dimensional motion pictures remain a novelty. Despite the wide appeal to viewers, the difficulties and burden on motion picture producers, distributors, motion picture theaters, and on the viewers has been a barrier to their wide scale acceptance. [0017] Vision [0018] The Human Eye and Depth Perception [0019] The human eye can sense and interpret electromagnetic radiation in the wavelengths of about 400 to 700 nanometers—visual light to the human eye. Many electronic instruments, such as camcorders, cell phone cameras, etc., are also able to sense and record electromagnetic radiation in the band of wavelengths 400-700 nanometer. [0020] To facilitate vision, the human eye does considerable ‘image processing’ before the brain gets the image. As examples: 1. When light ceases to stimulate the eyes photoreceptors, the photoreceptors continue to send signals, or ‘fire’ for a fraction of a second afterwards. This is called ‘persistence of vision’, and is key to the invention of motion pictures that allows humans to perceive rapidly changing and flickering individual images as a continuous moving image. 2. The photoreceptors of the human eye do not ‘fire’ instantaneously. Low light conditions can take a few thousands of a second longer to transmit signals than under higher light conditions. Causing less light to be received in one eye than another eye, thus causing the photoreceptors of the right and left eyes to transmit their ‘pictures’ at slightly different times, explains in part the Pulfrich 3-D illusion, which is utilized in the invention of a 3-D Phenomenoscope. This is also cause of what is commonly referred to as ‘night vision’. [0023] Once signals are sent to the eye, the brain process the dual stereo images together (images received from the left and right eye) presenting the world to the human eye in 3-dimensions or with ‘Depth Perception’. This is accomplished by several means that have been long understood. [0024] Stereopsis is the primary means of depth perception and requires sight from both eyes. The brain processes the dual images, and triangulates the two images received from the left and right eye, sensing how far inward the eyes are pointing to focus the object. [0025] Perspective uses information that if two objects are the same size, but one object is closer to the viewer than the other object, then the closer object will appear larger. The brain processes this information to provide clues that are interpreted as perceived depth. [0026] Motion parallax is the effect that the further objects are away from us, the slower they move across our field of vision. The brain processes motion parallax information to provide clues that are interpreted as perceived depth. [0027] Shadows provide another clue to the human brain, which can be perceived as depth. Shading objects, to create the illusions of shadows and thus depth, is widely used as in the shading of text to produce a 3-dimensional impression without actually penetrating (perceptually) the 2-D screen surface. [0028] 3-D Motion Pictures [0029] Methods of Producing 3-D Illusion in Moving Pictures [0030] Motion pictures are images in 2-dimensions. However, several methods have been developed for providing the illusion of depth in motion pictures. These include the Pulfrich, and Analglyph 3-dimensional illusions. [0031] Analglyph 3-Dimensional Illusion [0032] “Analglyph” refers to the red/blue or red/green glasses that are used in comic books and in cereal packets etc. The glasses consist of nothing more than one piece of transparent blue plastic and one piece of transparent red plastic. These glasses are easy to manufacture and have been around since the 1950s. [0033] An analglyph stereo picture starts as a normal stereo pair of images, two images of the same scene, shot from slightly different positions. One image is then made all green/blue and the other is made all red, the two are then added to each other. [0034] When the image is viewed through the glasses the red parts are seen by one eye and the other sees the green/blue parts. This effect is fairly simple to do with photography, and extremely easy to do on a PC, and it can even be hand-drawn. The main limitation of this technique is that because the color is used in this way, the true color content of the image is usually lost and the resulting images are in black and white. As the colors compete for dominance they may appear unstable and monochromatic. A few images can retain their original color content, but the photographer has to be very selective with color and picture content. [0035] Pulfrich 3-Dimensional Illusion [0036] Pulfrich was a physicist that recognized that images that travel through a dark lens take longer to register with the brain than it does for an image that passes through a clear lens. The delay is not great—just milliseconds—just enough for a frame of video to arrive one frame later on the eye that is covered by a darker lens than a clear lens. Pulfrich spectacles then have one clear lens (or is absent a lens) that does not cause a delay, and one darkened lens that slightly delays the image that arrives to the eye. In a motion picture viewed through Pulfrich lenses, for an object moving laterally across the screen, one eye sees the current frame and the other eye a previous frame. [0037] The disparity between the two images is perceived as depth information. The brain assumes both frames belong to the same object and the viewer's eyes focus on the object as if it were closer than it is. The faster the object moves, the more separation there is between the time-delayed images, and the closer the object appears. The fact that faster objects appear closer than slower objects also coincides with the principles of motion parallax. Generally, however, the greater displacements frame to frame (and now eye to eye) result from degrees of closeness to the recording camera (proximity magnifies), so that Pulfrich viewing can deliver an approximately correct and familiar depth likeness. While the depth likeness is unquestionably 3-D, it may differ from the fixed constant of an individual's inter-ocular distance when observing the world directly. Few observers will notice this anymore than they are bothered by the spatial changes resulting from use of telephoto or wide-angle lens in filming scenes. [0038] Motion pictures made for the Pulfrich method can be viewed without any special glasses—appearing as regular motion pictures minus the 3-D effect. Also, motion pictures made without regard for the Pulfrich effect, will still show the 3-D visual effect if lenses are worn and appropriately configured. [0039] The limitation of the Pulfrich technique is that the 3-dimensional illusion only works for objects moving laterally or horizontally across the screen. Motion pictures made to take advantage of these glasses contain lots of horizontal tracking shots or rotational panning shots to create the effect. The illusion does not work if the camera doesn't shift location (of subject matter remaining static), but vertical camera movement will create horizontal movement as field of view expands or contracts. Pulfrich, who first described this illusion, was blind in one eye, and was never able to view the illusion, though he completely predicted and described it. [0040] A basic example of the Pulfich illusion can be seen by viewing either of two TV stations. The news headlines on the CNN Television network or the stock market quotations on CNBC scroll in from the right of the TV screen and across and off the screen to the left. The news or quotations appear in a small band across the bottom of the screen while the network show appears above the scrolling information. When either of these network stations is viewed through Pulfrich glasses, with the darkened lens covering the left eye and the clear lens covering the right eye, the scrolling information appears in vivid 3-dimensions appearing to be in front of the TV screen. If the lenses are reversed with the clear lens covering the left eye and the darkened lens covering the right eye, the scrolling information appears to the viewer as receded, and behind the TV screen. [0041] Another example of the Pulfrich illusion can be seen in the movie ‘The Terminator’, starring Arnold Schwarzenegger. Any off-the-shelf copy of the movie—VCR tape, or DVD, can be viewed on a TV or PC playback display monitor as originally intended by the filmmaker. But, viewing scenes that include lateral motion from ‘The Terminator’, such as the scene when Sarah Connors enters a bar to call police (about 29 minutes into the movie) when viewed through Pulfrich glasses (left eye clear lens and right eye dark lens) shows the scene vividly in 3-dimensions, even though this visual effect was totally unintended by the director and cinematographer. [0042] Another stunning example is the famous railroad yard scene from “Gone with the Wind”, in which Scarlett O'Hara played by Vivien Leigh walks across the screen from the right as the camera slowly pulls back to show the uncountable wounded and dying confederate soldiers. When viewed through Pulfrich glasses with (left eye clear lens and right eye dark lens), the scene appears to the user in 3-dimensions, even thought it was totally unintended by the director and cinematographer. Interesting here is that the main movement of this scene was created by the camera lifting and receding and so expanding the view. Effective lateral motion resulting from such camera movement would in fact be to only one side of the screen, which the viewers will utilize to interpret the entire scene as in depth. [0043] The 3-D Phenomenoscope will allow any movie, such as “Gone with the Wind” which was shot in 1939, to be viewed in part in 3-dimensions. And with the 3-D Phenomenoscope this new viewing experience does not require any additional effort on the part of the owners, producers, distributors, or projectionists of the motion picture—just that the viewer don the 3-D Phenomenoscope viewing glasses. [0044] Note that the Pulfrich 3-D effect will operate when the left or right filtering does not correspond with the direction of foreground screen movement. The depth-impression created is unnatural, a confusion of sold and open space, of forward and rear elements. When confronted by such anomalous depth scenes, most minds will ‘turn off’, and not acknowledge the confusion. For normal appearing 3-D, mismatched image darkening and foreground direction must be avoided. [0045] We have described the need to match horizontal direction of foreground screen-movement to Left or Right light-absorbing lens. This, however, is a rule that often has to be judiciously extended and even bent, because all screen-action appropriate to Pulfrich 3-D is not strictly horizontal; horizontal movements that angle up or down, that have a large or even dominant element of the vertical, may still be seen in depth. Even a single moving element in an otherwise static scene can be lifted into relief by way of an adroit application of a corresponding Pulfrich filter. There would even be times when a practiced operator would choose to schedule instances of lens-darkening contrary to the matching-with-foreground-direction rule; the explanation for this lies in the fact that the choice of left or right filter-darkening will pull forward any object or plane of action moving in a matching direction, and there are times when the most interesting action in a picture for seeing in 3D could be at some distance from the foreground, even requiring a Left/Right filter-match at odds with the filter-side that foreground-movement calls for. For instance, if one wished to see marchers in a parade marching Left, to lift them forward of their background would require darkening of the Left lens, but foreground movement could be calling for a Right lens darkening; this would be a situation when a choice might be made to over-ride the foreground-matching rule. In most instances the rule is to be followed, but not mechanically; screen movement is often compound and complex, and an observant individual could arrange a Pulfrich timing for a movie with an alertness to such subtleties that did not limit decisions to recognition of foreground direction alone. As mentioned earlier, there would even be times, when the recording camera had moved either forward or backwards through space, when both Left and Right lenses would half-darken to either side of their centers, outer halves darkening moving forward (with picture elements moving out to both sides from picture-center) or both inner halves darkening when retreating backwards (with picture elements moving in towards center from each side). [0046] One might think that alternating between the screen-flatness of a dialogue scene and the deep space of an action scene would disrupt the following of a story. In fact, just as accompanying movie-music can be intermittent while entirely supporting a story development, dialogue is best attended to with the screen flat and action-spectacle is most effective given the dimension and enhanced clarity of depth. Usually a function of lighting specialists, it is always necessary to make objects and spaces on a flat screen appear distinct from each other; besides making a scene move convincing, 3-D separation of forms and of spatial volumes one from the other speeds up the “reading” of what are essentially spatial events. This is to say: flat can best enable concentration on dialogue; depth-dimension can most effectively deliver action scenes. Alternating between 2-D and 3-D awareness is something we even do, to a degree, in our experience of actuality, as a function of our changing concentration of attention; jut as we hear things differently when we concentrate on listening. Then, too, making sense of movies is a thing we learn to do, as different from life-experience as a movie is with its sudden close-ups and change of angle and of scene, its flashbacks, et cetera. Movie viewing is a learned language, a form of thinking; the alternating of flat-screen information with depth-information will be as readily adapted to as any other real-world-impossibility accepted without question as natural to the screen. [0047] In the preferred embodiment of the 3-D Phenomenoscope invention—we focus on a better means to present the Pulfrich 3-D illusion in motion pictures. In other embodiments of the invention, similar principles can be utilized to present other illusions or special effects in motion pictures. While the preferred embodiment uses a simple algorithm to identify passages of lateral movement in the motion picture that will display as a 3-dimensional effect when viewed using the 3-D Phenomenoscope, other embodiments may use more complex algorithms capable of identifying some or all of the screen action that may benefit from a Pulfrich effect. [0048] Problems with 3-D Motion Pictures [0049] With the exception of Sony I-Max 3-d, a special cine-technology requiring theaters designed for its screening requirements, 3-dimensional motion pictures have never caught on, except as a short-term fad, because a myriad of problems continue to make 3-dimensional motion pictures unacceptable to producers and viewers of motion pictures. Despite concerted efforts, 3-dimensonal motion pictures continue to be nothing more than a novelty. There are many problems and constraints involving the production, projection, and viewing of 3-dimensional motion pictures. [0050] Production: The commonly used analglyph 3-dimensional movie systems require special cameras that have dual lenses, and capture 2-images on each frame. To have a version of the motion picture that can be viewed without special glasses requires that a separate version of the motion picture be shot with a regular camera so there is only one image per video frame and not simply the selection of one or the other perspective. [0051] Projection: Some 3-dimensional systems require the synchronization and projection by more than 2 cameras in order to achieve the effect. “Hitachi, Ltd has developed a 3D display called Transpost 3D which can be viewed from any direction without wearing special glasses, and utilize twelve cameras and rotating display that allow Transpost 3D motion pictures that can be seen to appear as floating in the display. The principle of the device is that 2D images of an object taken from 24 different directions are projected to a special rotating screen. On a large scale this is commercially unfeasible, as special effects in a motion picture must be able to be projected with standard projection equipment in a movie theater, TV or other broadcast equipment. [0052] Viewing: As a commercial requirement, any special effect in a motion picture must allow viewing on a movie screen, and other viewing venues such as TV, DVD, VCR, PC computer screen, plasma and LCD displays. From the viewer's vantage, 3-dimensional glasses, whether analglyph glasses or Pulfrich glasses, which are used in the majority of 3-dimensional efforts, if poorly made or worn incorrectly are uncomfortable and may cause undue eyestrain or headaches. Experiencing such headache motivates people to shy away from 3-D motion pictures. [0053] Because of these and other problems, 3-dimensional motion pictures have never been more than a novelty. The inconvenience and cost factors for producers, special equipment projection requirements, and viewer discomfort raise a sufficiently high barrier to 3-dimensional motion pictures that they are rarely produced. A main object of this invention is to overcome these problems and constraints. [0054] Attempts to Overcome the Problems of 3-D Motion Pictures [0055] Different formulations of shutter glasses have been implemented over the last few decades, but without much large-scale commercial success. A shutter glasses solution generally require two images for each image of video, with shutter covering or uncovering each eye of the viewer. This allows one eye to see, than the other, with the shutters timed and synchronized with the video so that each eye only sees the image intended for it. Recent advances have eliminated mechanical shutter, and now use lens that turn opaque when an electric current is passed through it. [0056] Some shutter glass systems are wired to a control device while some shutter glass systems use wireless infrared signaling to control the state of the lenses. [0057] CrystalEyes is the name of a stereoscopic viewing product produced by the StereoGraphics Corporation of San Rafael, Calif. They are lightweight, wireless liquid crystal shuttering eyewear that are used to allow the user to view alternating field sequential stereo images. The source of the images alternately displays a left-eye view followed by a right-eye view. CrystalEyes' shutters can block either of the user's eyes so that only images appropriate for each eye are allowed to pass. A wireless infrared communications link synchronizes the shuttering of the eyewear to the images displayed on the monitor or other viewing screen. CrystalEyes shutter glasses, weight only 3.3 ounces, use two 3V lithium/manganese dioxide batteries, and have a battery life of 250 hours. This demonstrates the robustness and potential of a viewer glass solution. [0058] Because shutter glasses only expose each eye to every other frame, the refresh rate of the video is effectively cut in half. On a TV with refresh rates of 30 frames per second (for an NTSC TV) or 25 frames per second (for a PAL TV), this is hard on the eyes because of the continual flicker. This problem is eliminated with higher refresh rates, such as on PC monitors. [0059] However, shutter systems have not been overwhelmingly commercially successful. Motion pictures that use such stereo shutter systems require two frames for each frame of regular film. Motion pictures would then have to be produced in at least 2 versions. Also, except on high refresh rate systems, such as expensive PC monitors, the viewer sees too much ‘flicker’ causing distraction and annoyance. An additional requirement and burden is the wired or wireless signaling to control the state of the lens. LCD screens that are used on laptops generally do not have high enough refresh rates for stereoscopic shutter 3D systems. Shutter systems generally do not work well with LCD or movie projectors. [0060] In the preferred embodiment of this invention, in a manner similar to that used with some versions of shutter glasses, we utilize lens materials that are clear when no current is passed through it, but partially occluded or darkened when a current above a threshold voltage is passed through it. SUMMARY OF THE INVENTION [0061] Preferred embodiments of the 3-D Phenomenoscope invention solve the foregoing (and other) problems, and present significant advantages and benefits by providing a system to view 3-dimensional and other special effects in motion pictures. It is, therefore, an object of the preferred embodiment of the invention to provide a system by which ordinary 2-dimensional motion pictures can be viewed in part as a 3-dimensionsal experience. [0062] The 3-D Phenomenoscope achieves this by taking advantage of the well-known Pulfrich effect, through which lateral motion of an ordinary motion picture will appear to the viewer in 3-Dimensions. [0063] Ordinary glasses are configured with; (a) Right and left lenses for which the darkening of the glasses can be individually controlled (b) Digital photo sensors (digital camera) that can capture the viewed motion picture as successive images and convert the captured frames to digital images for processing (c) Computer processor and computer program to process the successive images and identify the synchronization events, and (d) Means to provide individual control for the darkening of the right and left hand lenses based on the identified synchronization events. [0068] Unlike prior inventions that used shutter glasses, in the preferred embodiment of the invention, the control for the viewing glasses is not a wired, wireless or infrared signal, but information calculated in real-time from successive frames of the motion picture. We add to viewing glasses that have individually controllable lens, a photo sensor to convert the analog video image to a digital format, and a computer processor to process the digital image and calculate from successive file frames the synchronization signals to control the state of the 3-D Phenomenoscope right and left lenses and produce the desired video effect. [0069] In the preferred embodiment, the lenses of the viewing goggles may take 3 different states; (a) clear-clear for the right and left eyes; (b) clear-darkened for the right and left eyes, and; (c) darkened-clear for the right and left eyes. In other embodiments, the lenses may be capable of various other states that correspond to different levels of darkening. [0070] In the preferred embodiment, the viewing glasses look just like ordinary lightweight glasses—2 lenses, earpieces, and a nose rest. The viewing glasses also have an attached digital sensor that ‘sees’ and quantifies the digital snapshot captured by the digital sensor. For each frame, an algorithm operating on a computer processor that is attached and part of the 3-D Phenomenoscope, is able to process the successive images digital images, identify lateral movement and synchronization events, and cause the lenses of the viewing glasses to assume the appropriate right-left lens states. [0071] In this way the viewing glasses work regardless of the viewing media—TV, film, DVD, computer monitor, liquid crystal display, plasma display, etc. [0072] The preferred embodiment of the 3-D Phenomenoscope invention overcomes problems of providing 3-dimensional illusions in motion pictures and achieves the following major benefits: 1. No special equipment is needed for the filming of the motion picture. Ordinary film or digital technology can be used to shoot the movie. The motion picture can even be the result of animation. 2. Works equally well whether the movie is released in any of the various film or digital formats. 3. Allows older or motion pictures produced before the invention of the 3-D Phenomenoscope to be viewed with a 3-dimensional effect. 4. No special equipment is needed for the projection of the motion picture. The movie can be viewed on a TV, DVD player, PC, or in a movie house. 5. The battery-powered viewer glasses are controlled in real-time by an intelligent processor packaged with the glasses, so 3-dimensional viewing works equally well whether the movie is viewed on a TV, DVD player, PC, or in a movie house. 6. Since darkening of the lenses to obtain the 3-dimensional illusion is only activated when sustained lateral motion is detected, eyestrain and discomfort is greatly reduced. BRIEF DESCRIPTION OF THE DRAWINGS [0079] Many advantages, features, and applications of the invention will be apparent from the following detailed description of the invention that is provided in connection with the accompanying drawings in which: [0080] FIG. 1 is a block diagram illustrating a preferred embodiment of the 3-D Phenomenoscope. [0081] FIG. 2 is a block diagram illustrating use of the 3-D Phenomenoscope to view an ordinary motion picture with a 3-dimensional effect. [0082] FIG. 3 is a block diagram showing the 3 different right and lens configurations and how they are synchronized to the foreground lateral motion of the motion picture. [0083] FIG. 4 is a block diagram of the Glass Lens Controller Unit, or GLCU 103 . [0084] FIG. 5 is a flowchart for the operation of the lens control algorithm. [0085] FIG. 6 is the decision procedure used by the real-time control algorithm to control the state of viewer glasses. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0086] Preferred embodiments and applications of the invention will now be described with reference to FIGS. 1-6 . Other embodiments may be realized and structural or logical changes may be made to the disclosed embodiments without departing from the spirit or scope of the invention. Although the invention is particularly described as applied to the viewing of motion pictures that include scenes that can benefit from the Pulfrich 3-dimensional illusion, it should be readily apparent that the invention may be embodied to advantage for other visual effects. [0087] In particular, the invention is readily extendable to other embodiments resulting in other motion picture video effects that result from the processing of the motion picture images by a processor on the viewing glasses, and the resulting control of the viewing glasses lenses. It is also readily extendable to other algorithms that can detect passages of screen motion that can benefit from the Pulfrich effect other than the simple lateral movement described in the preferred embodiment. [0000] Technologies Utilized in the Invention [0088] Substances that Change Color and Transparency [0089] Objects that change color have been well known for a long time. Animate creatures such as cephalopods (squid) have long been known for their ability to change color seemingly at will, by expanding or retracting chromatophore cells in their body. [0090] There are many different technologies that are used to cause physical materials to change their color and transparency. These may react to heat, light, ultraviolet light, or electronic means to change their state, which in turn affect how they reflect and refract light, or their properties of transparency, or translucency. [0091] For instance, photochromatic lenses automatically darken in sunlight and lighten when indoors, and have been utilized in sunglasses for many years. Some may darken instantaneously, and others have lenses that take several different shades depending upon the intensity of the light presented. [0092] Thermochromatic materials are heat activated, causing the color to change when the activation temperature is reached, and reverse the color change when the area begins to cool. These are used in such products as inks, and strip thermometers. [0093] LEDs (Light Emitting Diodes) are electronic diodes that allow current to flow in one direction and not the other. LEDs have the unique “side effect” of producing light while electricity is flowing through them. Thus they have two states—when electricity flows through them they are ‘on’ and emit light, or ‘off’ when no electricity flows through them and they do not emit light. [0094] Phosphors are emissive materials that are used especially in display technologies and that, when exposed to radiation, emits light. Any fluorescent color is really a phosphor. Fluorescent colors absorb invisible ultraviolet light and emit visible light at a characteristic color. In a CRT, phosphor coats the inside of the screen. When the electron beam strikes the phosphor, it makes the screen glow. In a black-and-white screen, there is one phosphor that glows white when struck. In a color screen, there are three phosphors arranged as dots or stripes that emit red, green and blue light. In color screens, there are also three electron beams to illuminate the three different colors together. There are thousands of different phosphors that have been formulated, and that are characterized by their emission color and the length of time emission lasts after they are excited. [0095] Liquid crystals are composed of molecules that tend to be elongated and shaped like a cigar, although scientists have identified a variety of other, highly exotic shapes as well. Because of their elongated shape, under appropriate conditions the molecules can exhibit orientational order, such that all the axes line up in a particular direction. One feature of liquid crystals is that electric current affects them. A particular sort of nematic liquid crystal, called twisted nematics (TN), is naturally twisted. Applying an electric current to these liquid crystals will untwist them to varying degrees, depending on the current's voltage. These crystals react predictably to electric current in such a way as to control light passage. [0096] Still another way to alter the amount of light that passes through a lens is with Polaroid lenses. Polaroids are materials that preferentially transmit light with polarization along one direction that is called the polarization axis of the polaroid. Passing unpolarized light through a polaroid produces transmitted light that is linearly polarized, and reduces the intensity of the light passing through it by about one-half. This reduction in light from a first polaroid does not depend on the filter orientation. Readily available optically active materials are cellophane, clear plastic tableware, and most dextrose sugars (e.g. Karo syrup). Materials that alter the polarization of light transmitted through them are said to be optically active. [0097] If two polaroids are placed immediately adjacent to each other at right angles (crossed) no light is transmitted through the pair. If two similar polaroids immediately adjacent to each other are in complete alignment, then the second polaroid does not further reduce the intensity of light passing though the first lens. Additional reduction of light intensity passing through the first polaroid lens will occur if the two similar polaroids immediately adjacent to each other are in other then complete or right angle alignment. This can be beneficially used in other embodiments of the invention to more precisely control the intensity of light passing through the 3-D Phenomenoscope lenses. [0098] Polaroids can be actively controlled by electronic currents, and are used in such products as LCD displays. For example digital watches often use LCD display for the display of time. In such products, there is a light source behind two layers of LCD materials. Electronic current is used to control the polarity of specific areas of the two layers. Any area of the screen for which the two polaroid layers are at right angles to each other will not pass any light—other areas will allow light to pass. In this manner, the alphanumeric information of LCD can be electronically controlled and displayed on an LCD display. [0099] Another technology to control the intensity of light passing through the lenses includes directional filters such as the micro-louver. [0100] In the preferred embodiment of this invention, we utilize liquid crystals for the lenses that change transparency when an electronic current is passed through them. In particular, we use a substance that is darkened (allowing some light to pass through) when current is applied across it, but is clear and transparent and allows light to pass unhindered when no current is applied to it. In other embodiments of the invention, other substances and technologies could be used that allow the lenses to change their color, or their properties of transparency or translucency. [0101] Digital Photo Sensors [0102] Small, inexpensive, low power digital photo cameras are becoming ubiquitous. Many cell phones now feature the ability to take a still or video picture using a camera included as part of the phone. The pictures and/or video are processed on the cell phone and can then be sent wirelessly over the cell phone network, or stored in digital format on the phone. [0103] Just as the light sensitive nerves of the eye called photoreceptors (rods and cones) convert light to electrical impulses that are sent to the brain via the optic nerve, digital photographic instrument have materials that act like human photoreceptors, translating visual light into a measurable quantity that represents its color, and sending the encoded color to a processor via electronic circuitry. [0104] Digital sensors consist of an array of “pixels” collecting photons, the minute energy packets of which light consists. The number of photons collected in each pixel is converted into an electrical charge by the light sensitive photodiode. This charge is then converted into a voltage, amplified, and converted to a digital value via the analog to digital converter, so that the camera can process the values into the final digital image. [0105] The ‘eye’ of such digital photographic instruments senses light and translates it into a number representing a color. For instance the ‘eye’ of the instrument may be capable of resolving the color to any of a fixed number (16, 64, 64K, etc) of colors, and does it at discrete evenly spaced increments—pixels. For instance, a common field of vision for a digital photographic instrument may be a rectangular area with 640×480 pixels, and each pixel may be able to accurately sense and record the color to one of 256 different colors. Such photographic qualities are common now in low-end digital cameras and video recorders. Higher end digital cameras may achieve 35 mm quality pictures with resolutions of 3000 pixels per inch, and are able to distinguish 65 K different colors (or even higher). [0106] One such camera is the Flycam CF, manufactured by the LifeView Company, located at 46781 Fremont, Blvd., Fremont, Calif. 94538, USA. The Flycam CF can capture video at up to 30 fps, and weights only 20 grams (seven tenths of an ounce). [0107] A common way for such instruments to quantify light is to measure the levels of ‘red’, ‘green’ and ‘blue’ color (575, 535, and 445 nanometer wavelengths respectively). Every color in the visual light spectrum can be represented as a triad of these three colors. [0108] This is similar to how our eyes work. The cone-shaped cells inside our eyes are sensitive to red, green, and blue—the “primary colors”. We perceive all other colors as combinations of these primary colors. In conventional photography, the red, green, and blue components of light expose the corresponding chemical layers of color film. The newly developed Foveon sensors are based on the same principle, and have three sensor layers that measure the primary colors. Combining these color layers results in a digital image, basically a mosaic of square tiles or “pixels” of uniform color which are so tiny that it appears uniform and smooth. [0109] Many other inventions utilize the triad of ‘red’, ‘green’, and ‘blue’ to represent pictures. Color film is a layer of three emulsions, each sensitive to a different one of these three colors. Cathode Ray Color Tube (CRT) technology, is a vacuum tube that emits beams of electrons that excite phosphorescent receptors on the screen that radiate light at these three different frequencies. [0110] Different technologies, well known in the art of photography have been developed to sense and measure light at distinct quantities known commonly as pixels, and send the measured quantity to a processor via electronic circuitry. In the preferred embodiment, we use an inexpensive and low-resolution photo lens, consisting of a 640×480 pixels and that can distinguish and record light as one of 256 different colors. In other embodiments, other digital photo lenses may be used, as for example, ones that have higher or lower resolutions. [0111] Miniature Special Purpose Computers [0112] The miniaturization of computers has advanced at a continuing and increasing pace—especially for special purpose computers that serve a dedicated function. As an example, digital hearing aids have been miniaturized to such an extent that they can fit almost undetected in the ear. [0113] Built around special purpose computer, digital hearing aid devices take analog sound presented to the ear, convert the sound to digital format, perform major signal process of the digitized sound, and then enhance the signal which is converted back to an analog signal and played to the user. A typical problem in older men is that they have progressively more hearing loss in higher than lower sound frequencies. Often older women have the reverse problem with progressively more hearing loss in lower rather than higher frequencies. Digital hearing aids can selectively enhance different ranges of frequencies, allowing hearing impaired users to hear normally. [0114] Other digital hearing aids address the ‘cocktail party’ problem. A person without hearing impairment is able to ‘mute’ out the surrounding sound at a cocktail party, and just focus on conversation with a person directly in front of them. The hearing impaired progressively loses this ear/mind ability. But the cues and process by which this muting is done is in part understood, and digital hearing aids can digitally replicate this process and process sound to simulate the way a normal person ‘mutes’ out surrounding sound. [0115] Global Positioning chips provide another example of a special purpose miniaturized, low-power dedicated computer-on-a-chip that performs complex functions. The constellation of Global Positioning Satellites (GPS) that make up the system, broadcast signals that allow GPS receivers to identify their position on the earth surface to within a few meters of accuracy. GPS chips are the real-time processor for terrestrial appliances (such as cell phones) to accurately identify geographic position, and can lock-onto the spread-spectrum signal of multiple satellites, perform analog-to-digital (A/D) conversion of the signals, extract several different formats of signals, and perform complex trigonometric calculations to triangulate and determine the base-stations geographic position on the earth. [0116] Special purpose and dedicated computer miniaturization provides a level of technology in which miniaturized computers weight little, are rugged, powerful, small, perform extremely complicated mathematical and processing functions in real-time, and run on small and light-weight batteries for several weeks at a time. Such a special purpose computer will be utilized in the preferred embodiment of the invention. [0117] Algorithms to Detect Movement in Motion Pictures [0118] Early motion detectors were entirely analog in nature but completely suitable to monitor situations where no motion is to be expected, such as restricted areas in museums, and stores when they are closed for the evening. Recent advances in digital photography and computers have allowed new means to monitor such situations, and incorporate digital video systems that can passively record images at set time intervals (e.g. 15 frames per second), computer processors to process the image and detect motion, and cause appropriate action to be taken if motion is detected. [0119] Many different algorithms have been developed for computer processing of images that can be used to determine the presence of lateral movement in a motion picture, as well as identifying the direction of lateral motion. In the future new algorithms will continue to be developed. Any algorithm that can process sequences of digital images, and detect motion and the direction of motion can be used in the invention. [0120] The selection for the lens control algorithm may depend on the computational power of the attached 3-D Phenomenoscope processor, requiring the selection of algorithm that is appropriate to the level of its computational power. [0121] In the preferred embodiment we will utilize an intensity edge map algorithm. Edge-based algorithms have been used in digital cameras as part of the means to implement functions such as auto-focus. Edge-based algorithms utilize information that can be calculated from the discontinuities between adjoining pixels of the digitized image. For instance, consider a person standing against a light background. The edge pixels of the person can be clearly identified because of the sudden change in pixel value. Edge-based algorithms generally identify such intensity edges in the image, eliminate all other pixels (for instance by changing them from their recorded value to ‘white’), and then process the image based solely on the identified intensity edges. Region-based algorithms that group together pixels having similar properties, are not used in the preferred embodiment, but may be incorporated for the lens control algorithm of other embodiments of the invention. [0122] In U.S. Pat. No. 5,721,692, Nagaya et al present a ‘Moving Object Detection Apparatus’. In that disclosed invention, a moving object is detected from a movie that has a complicated background. In order to detect the moving object, there is provided a unit for inputting the movie, a display unit for outputting a processed result, a unit for judging an interval which is predicted to belong to the background as part of a pixel region in the movie, a unit for extracting the moving object and a unit for calculating the moving direction and velocity of the moving object. Even with a complicated background in which not only a change in illumination condition, but also a change in structure occurs, the presence of the structure change of the background can be determined so as to detect and/or extract the moving object in real time. Additionally, the moving direction and velocity of the moving object can be determined. Such an apparatus as in used by Nagaya, or in other inventions or algorithms for moving object detection, may be incorporated in some embodiments of the 3-D Phenomenoscope as a means to identify the synchronization events controlling the viewer glasses. [0000] Detailed Description of the Figures Preferred Embodiment [0123] FIG. 1 [0124] FIG. 1 is a block diagram 100 illustrating a preferred embodiment of the 3-D Phenomenoscope invention for connection-free Pulfrich glasses [0125] For exemplary purposes, FIG. 1 shows the 3-D Phenomenoscope in one of the three states that the lenses can take. FIG. 1 shows the right lens 101 darkened and the left lens 102 as clear. This is the configuration to view a motion picture with a 3-dimensional effect in which the lateral motion is moving from left-to-right on the viewing screen [0126] In the preferred embodiment, the viewing glasses 110 consist of a right lens 101 , a left lens 102 , and a Glass Lens Controller Unit (GLCU) 103 . The GLCU 103 includes a digital sensor to take pictures or snapshots of the displayed motion picture, a processor to process the recorded images in successive frames and identify synchronization events, and can send signals to independently control the darkness of the right and left lenses based on the detected synchronization events. [0127] In the preferred embodiment the viewing glasses may contain the GLCU 103 as an integrated part of the lenses. Other embodiments of the invention may have 3-D Phenomenoscope viewing glasses that fit over regular prescription glasses in a manner similar to that in which snap-on or clip-on sunglasses are configured. [0128] FIG. 2 [0129] FIG. 2 is a block diagram 200 illustrating use of the 3-D Phenomenoscope to view 125 an ordinary motion picture with a 3-dimensional effect. [0130] In the preferred embodiment the motion picture 120 is a regular motion picture consisting of consecutive frames 121 or pictures that make up the motion picture. As the motion picture 120 is played for the viewer, the GLCU 103 unit records discrete images of the motion picture, digitally processes the successive images to identify synchronization events, and uses the synchronization event to control the darkness state of the right and left lenses of the 3-D Phenomenoscope viewing glasses. [0131] Four consecutive frames of a similar scene 121 - 124 are displayed with lateral motion moving across the motion picture from the left to the right direction. The foreground figure is passing in front of a figure of a vehicle in the background. The left lens 102 is shown in a clear state, and the right lens 101 is shown in a dark state, which is the Pulfrich Filter Spectacles 110 configuration to view the displayed left-to-right lateral motion with the Pulfrich 3-D visual effect. [0132] The motion picture media is shown pictorially as regular film, though the preferred embodiment works equally well if the media is any form for digital motion pictures. The invention works equally well with any of the formats of regular film. [0133] FIG. 3 [0134] FIG. 3 is a block diagram 300 showing the 3 lens states used by the 3-D Phenomenoscope. [0135] FIG. 3 a shows the lens states with the both the right and left lenses clear. Neither lens is darkened. This is the lens state that is used in the preferred embodiment when there is no significant lateral motion detected in the motion picture. [0136] FIG. 3 b shows the lens states with the left lens clear and the right lens darkened. Note that the left lens covers the viewers left eye, and the right lens covers the viewer's right eye. This is the lens state that is used in the preferred embodiment when foreground lateral motion is detected in the motion picture that is moving from the left to the right direction, as seen from the viewer's perspective. [0137] FIG. 3 c shows the lens states with the left lens darkened and the right lens clear. This is the lens state that is used in the preferred embodiment when the foreground lateral motion is detected in the motion picture that is moving from the right to the left direction, as seen from the viewer's perspective. [0138] In the preferred embodiment of the invention the lens state consisting of both left and the right lens darkened, is not used. This lens state can be achieved by the 3-D Phenomenoscope, and may have uses in other embodiments of the invention. [0139] In other embodiments of the invention, the right and left lenses of the viewing glasses may take a multiplicity of different levels of darkness to achieve different effects, resulting in more lens states that shown for demonstration purposes in the preferred embodiment. In particular, the darkening of the non-clear lens can be optimized according to the speed of lateral motion, so as to maximize the degree of 3-dimensional effect. [0140] FIG. 4 [0141] FIG. 4 is a block diagram 400 of the Glass Lens Controller Unit 103 (GLCU). First, light from the motion picture media frame 309 travels 313 to the digital sensor 301 of the Glass Lens Controller Unit 103 . The digital sensor 301 responds by digitizing the image and storing 312 the digitized image in a digital pixel array 310 . For simplicity, FIG. 4 shows the GLCU storing 312 only a single image of the motion picture. In the preferred embodiment the GLCU can store two or more successive images in the digital pixel array 310 . Processing to identify synchronization events is performed by comparing the successive images and determining the direction of lateral foreground motion. [0142] The digital pixel array 310 , the computer processor 305 , and the digital sensor 301 are powered 303 by a battery 302 . [0143] Running on the computer processor 305 , is a lens control algorithm 306 . The lens control algorithm 306 accesses 311 the digitized images stored in the digital pixel array 310 , and processes the digitized values representing the digitized media frames 309 . The lens control algorithm 306 can determine synchronization events and control the state of the left 102 and right 101 lenses of the viewing glasses 110 . The lens control algorithm accesses 311 the digitized images stored in the digital pixel array 310 . [0144] In the preferred embodiment of the invention, the lens control algorithm 306 uses an intensity edge finding algorithm to detect similar foreground objects in the successive frames of the motion picture. The lens control algorithm 306 , identifies the synchronization events by detecting the presence or absence of foreground lateral motion, and if there is foreground lateral motion, the direction of that motion. By comparing the position of the like object, the lens control algorithm 306 can determine whether there is motion in the motion picture, and the direction of the motion. Change in the presence or absence of motion, or a change in the direction of motion is a synchronization event used to control the darkness state of the lenses, and allow the viewer to view a motion picture with the illusion of 3-dimensions. The proper state of the lens, dark or clear, is controlled by an electronic signal 307 that controls the state of the left lens, and another electronic signal 308 to control the state of the right lens. [0145] If no lateral motion is detected in the motion picture, then the lenses are set to the configuration of FIG. 3 a , with both left and right lens clear. If lateral motion is detected moving across the screen from the left to the right, then the lenses are set to the configuration of FIG. 3 b , with a left lens clear, and the right lens darkened. If lateral motion is detected moving across the screen from the right to the left, then the lenses are set to the configuration of FIG. 3 c , with left lens darkened, and the right lens clear. [0146] In the preferred embodiment the lens state is clear when there is an absence of electrical current, and darkened when current above a threshold value is present. [0147] If the lens control algorithm cannot identify any foreground lateral motion in the motion picture, then the GLCU 103 sets the left and right lenses to clear-clear by causing no current to pass over the viewing glass left control circuit 307 , and no current over the viewing glass right control circuit 308 . If the lens control algorithm identifies foreground lateral motion in the motion picture moving from the left to the right of the motion picture, then the GLCU 103 sets the left and right lenses to clear-dark by causing no current to pass over the viewing glass left control circuit 307 , and current in excess of a threshold level to pass over the viewing glass right control circuit 308 . If the lens control algorithm identifies foreground lateral motion in the motion picture moving from the right to the left of the motion picture, then the GLCU 103 sets the left and right lenses to dark-clear by causing no current to pass over the viewing glass right control circuit 308 , and current in excess of a threshold level to pass over the viewing glass left control circuit 307 . [0148] Note that some digital sensors 301 may include memory to store the measured picture values and can read them out to a memory 310 on command, and other digital sensors 301 may have to read out the values continuously as they are converted from light to pixel values. In either case, the digital pixel array 310 captures the essence of what is required—that the digital sensor 301 convert light to numerical pixel values, and provide these numerical values to the processor 305 for storage in the digital pixel array 310 so the lens control algorithm 306 can process the values in successive media frames, and cause the viewer glasses 110 to take the appropriate state based on the detected synchronization events. [0149] FIG. 5 [0150] FIG. 5 is a flowchart for the operation of the lens control algorithm. It shows a flowchart 600 for the calculation by the lens control algorithm of the control parameters that synchronize the viewer lenses to the foreground lateral motion of the motion picture. For teaching purposes, the flowchart depicts a simplified algorithm, in which only two frames are read, processed, and compared for the presence of motion, and controlling instructions issued that set the state of the lenses of the viewer glasses. Other embodiments of the invention may consider longer sequences of frames to detect motion and identify synchronization events. [0151] In the preferred embodiment of this invention we utilize an intensity edge finding algorithm to identify vertical edges in the foreground of the motion picture, and then test for movement of this intensity edge across successive frames of the motion picture. If an intensity edge is identified as moving from the right to the left, then the 3-D Phenomenoscope left lens is set to dark, and the right lens set to clear. If the intensity edge is identified as moving from the left to the right, then the 3-D Phenomenoscope left lens is set to clear, and the right lens set to dark. If the intensity edge is determined not to be in motion, then both the right and left lens are set to a clear state. Other embodiments of the invention may use other algorithm to detect the direction of lateral motion, and set the left and right lenses of the 3-D Phenomenoscope accordingly. [0152] The algorithm begins by initialization at the ‘Start’ step 601 . It then reads a first media frame 610 . An intensity edge algorithm 611 searches for vertical edges in the frame, and identifies a single prominent vertical edge. Branching logic 612 takes one of two actions depending upon whether a vertical intensity edge has been identified. If no vertical edge has been selected 613 , then operation continues operation by re-reading a new first media frame 610 . If a vertical edge has been selected 614 , then operation continues by reading the next sequential media frame 620 . [0153] The same intensity edge algorithm that was used to process the first media frame is now used to process 621 the next sequential media frame. A list of all vertical intensity edges is identified, and compared 622 with the single prominent vertical intensity edge selected from the first media frame. If the single prominent vertical edge identified and selected from the first media frame is not found 623 in the list of vertical intensity edges from the second media frame, then operation continues by reading a first media frame 610 . If the single prominent vertical edge identified and selected from the first media frame is found 624 in the list of vertical intensity edges from the second media frame, then the operation continues by comparing the edges for the presence of motion 630 . [0154] If the comparison of the detected vertical intensity edges between the first media frame and the second media frame 631 , determines that there is no motion in the sequential frames, then the lens control algorithm sets the left and right viewer lenses to the state clear-clear 640 , and operation continues by reading a first media frame 610 . If the comparison of the detected intensity edges between the first media frame and the second media frame 632 , determines that there is motion in the sequential frames, then operation continues by considering the direction of motion. [0155] Comparison of the similar intensity edges is done to determine whether there is lateral translation of the edges. The first image is used to register the image, and then the second image compared with the registered image. A translation of the vertical edge of the registered image is interpreted by the algorithm as lateral motion. Its direction can be calculated. In other embodiments of the invention the speed of motion can determined and may be used advantageously in determination of the synchronization events. While the simplest algorithm is used in the preferred embodiment for teaching purposes, the algorithm will likely require that directional movement be detected across several frames to trigger a synchronization event. [0156] The vertical intensity edges are compared to determine if the lateral movement in the sequential frames is from left-to-right directions 634 . If there is left-to-right lateral movement detected 635 , then the lens control algorithm sets the left and right viewer lenses to the state clear-dark 641 . If the direction of movement is not left-to-right then the algorithm assumes the motion is in the right-to-left direction 636 , and the lens control algorithm sets the left and right viewer lenses to the state dark-clear 642 . In either case, operation continues with the reading of a first media frame 610 . [0157] The preferred embodiment uses the simple described intensity edge-based finding algorithm to identify the direction of lateral motion and use that to synchronize the darkness of the right and left lens to the foreground lateral motion. Other embodiments of the invention may use any other algorithm that can detect the direction of lateral motion in a motion picture to determine the synchronization events for control of the lenses. Other embodiments may use categories of image processing algorithms other than intensity edge-based algorithm to identify the synchronization events. Other embodiments may not only detect foreground lateral motion, but estimate parallax, the speed of lateral motion, etc, and use such information to determine the synchronization of the right and left lens darkening to the motion picture content. [0158] Simple lateral-left, or lateral-right screen movement is just one example of screen movement that can be used to advantage in the 3D Phenomenoscope. The preferred embodiment that has been described uses a simple algorithm to demonstrate the principles of the 3D Phenomenoscope by detecting such lateral motion in motion pictures. But as previously explained in the discussion of the principles of the Pulfrich illusion, other more complicated types of motion in a motion picture can provide a visual effect using the Pulfrich illusion, and these can also be detected by the Lens Control Algorithm and beneficially implemented in the 3D Phenomenoscope. [0159] In the preferred embodiment, a single prominent intensity edge is identified and its movement tracked across several frames to identify the direction of motion. Other embodiments may use algorithms that track a multiplicity of edge objects, and this can be used advantageously in other embodiments of the lens control algorithm to calculate synchronization events to control the 3D Phenomenoscope. For each such edge object the relative speed of motion and direction can be estimated from successive frames of the motion picture, and such calculated information used to identify different types of motion and related synchronization events. For instance if different edge objects on the left and right hand side of the screens are both moving at the same speed but in different directions, this may be an indication that the camera is either panning in or out, and may be used to control special configurations of lens occlusion densities. In another example, different edge objects moving in the same direction but at different speeds can be used to estimate parallax, which also may be used to control special configuration of lens hues [0160] In other embodiments of the invention, the processor may have a multiplicity of different lens control algorithms which may be selected either by the viewer, or selected under computer control. For instance, different lens control algorithms may be appropriate for black and white or color motion picture media. In this case, the selection of which lens control algorithm to use could be either detected by the Phenomenoscope and selected, or selected by the viewer using a selection button on the viewer glasses. [0161] Since identification of lateral movement in the film can be confounded by head-movement, other embodiments may use a lens control algorithm could detect such head movement, or the 3-D Phenomenoscope could otherwise need to account for it. The lens control algorithm can detect and correct for head movement by tracking the picture enclosing rectangle, and suitably accounting for any detected movement. Other embodiments may utilize motion detectors as part of the 3-D Phenomenoscope apparatus. The motion detectors would detect and measure head motion that would be used by the lens control algorithm to make suitable adjustments, or that could be used to trigger a heuristic rule operating in the lens control algorithm. For instance, such a heuristic rule may place the 3-D Phenomenoscope into a clear-clear state if any head movement is detected. [0162] More specifically in the preferred embodiment of the invention we can use any algorithm that can detect motion, and the direction of lateral motion. [0163] FIG. 6 [0164] FIG. 6 is the decision procedure used by the real-time control algorithm to control the state of viewer glasses. The decision procedure is used for control of the 3-D Phenomenoscope Pulfrich filters, and demonstrates how the right and left lenses of the viewer glasses are controlled based on the identification of synchronization events. [0165] Throughout the viewing of the motion picture the decision rule 700 is reevaluated based on processing of successive frame images as captured, recorded, digitized and processed by the 3-D Phenomenoscope apparatus. At each decision point in the processing, the decision rule first determines if a synchronization event has taken place—i.e. that the lenses of the viewer glasses need to be placed in one of the states where lenses have different states, so as to view lateral motion in the motion picture with a 3-dimensional effect. If no synchronization event is present then both of the lenses of the viewer glasses are set to clear a clear state. [0166] If a synchronization event has been identified, then the decision rule determines the type of synchronization event. The two types of synchronization events in the preferred embodiment are to synchronize the viewer glasses for left-to-right lateral motion on the screen, or to synchronize the viewer glasses for right-to-left lateral motion on the screen. [0167] If the synchronization event is for left-to-right lateral motion on the screen then the decision rule will cause the 3-D Phenomenoscope to take the state where the left lens is clear and the right lens is partially occluded or darkened. If the synchronization event is for right-to-left lateral motion on the screen then the decision rule will cause the 3-D Phenomenoscope to take the state where the right lens is clear and the left lens is partially occluded or darkened. [0168] In the preferred embodiment, the synchronization events are calculated by an intensity edge algorithm that is suited to detect foreground lateral motion in successive frames of the motion picture. Other embodiments of the invention may use entirely other means to identify synchronization events, which are then used by the decision rule for control of the lenses of the 3-D Phenomenoscope lenses. Other embodiments may have more than 2 synchronization events (states where the right and left lens take different hues), and would use similar though more complicated synchronization decision rules to control the lenses of the viewer glasses. [0169] The synchronization algorithm may also utilize various heuristic rules in determining a synchronization event. For instance, if the viewer lenses responding to rapidly detected changing lateral motion, switch states too rapidly, this may cause undue discomfort to the viewer. [0170] Rapid synchronization events may be a problem for people who are photosensitive—people who are sensitive to flickering or intermittent light stimulation. Photosensitivity is estimated to affect one in four thousand people, and can be triggered by the flicker from a television set. While photosensitive people may simply remove the 3-D Phenomenoscope, heuristic rules could be employed to reduce flicker and eliminate any additional photosensitivity from the 3-D Phenomenoscope. For instance, such a heuristic rules may implement logic in the synchronization decision rule that require that no change to a synchronization event can take place for a set number of seconds after the last synchronization event—i.e. a lens state must be active for a minimum length of time before a new state may be implemented. [0171] When a camera travels primarily forward or back, lateral movement can take place on both sides of the screen. To address this, a heuristic rule may set a default setting favoring one direction. Other approaches and equipment may allow the split lens which darken simultaneously with the inner halves darkening when the camera is retreating, or the two outer halves darkening when advancing. [0172] In other embodiments, detection of a synchronization event would change the state of the lenses for a specific length of time. For instance, the synchronization event may change the right and left lenses to a corresponding darkened-clear state for 10 seconds and then change back to a default state of clear-clear. Even if another synchronization event were to be detected in that 10 second interval, those subsequent synchronization events would be ignored. This would prevent too rapid changes to the state of the lenses that might be uncomfortable for the viewer. [0173] It may be preferable to only activate the 3-D Phenomenoscope when sustained lateral movement is detected—i.e. a couple of seconds after the lateral motion is first detected. This would be accomplished using a heuristic rule that only engages the synchronizations a set length of time after sustained motion has been detected. Since individuals' have different levels of photosensitivity, the sustained lateral movement time interval could be set or selected by the viewer to reflect their own comfort level. [0174] Heuristic rules may be implemented in the decision rule to account for other situations in the determination of synchronization events. Other Embodiments [0175] The preferred embodiment is an implementation of the invention that achieves great benefit to the viewer of a motion picture by using timed signals that are determined by apparatus included in the 3D Phenomenoscope to move a Pulfrich filter before one eye or the other as appropriately synchronized to the current direction of screen foreground movement. It described filtering spectacles with no moving parts and no wire connections and use material that partially occludes or entirely clears the lenses of the Pulfrich filter in response to the electronic signal. [0176] Synchronization [0177] In other embodiments of the invention, the user can select which parts of the media frame are to be searched for synchronization and control information. The CNN scrolling news headlines provides a good example of a situation where lateral motion is isolated in only a single area of the screen. CNN scrolling news headline appear along a small horizontal strip at the bottom of the screen, generally with a commentator providing other news coverage, with little if any lateral motion that could be used to advantage by the Pulfrich effect. In this case, it would be preferable to have the intensity edge algorithm search only the lower part of the screen for lateral motion. [0178] Other embodiments of the invention may benefit from several levels of occlusion (other than just clear and one level of darkness) of the lenses of the viewer glasses. In general the slower the foreground lateral motion, the more darkening (delay of the image reaching one eye) is necessary to produce a Pulfrich video effect. Other embodiments may in addition to the direction of foreground lateral motion, also estimate the speed of foreground lateral movement, and use this to provide corresponding synchronization events with different levels of occlusion to one of the lenses of the viewer glasses, so as to maximize the visual effect for the viewer. By similar means, other aspects of the recorded image, such as Parallax may be measured and used. [0179] Another embodiment requires that the synchronization events be predetermined and incorporated into the motion picture video. This is implemented by single distinct frames of the motion picture, which identify the synchronization events. If a digital cinema projector is used, then each 3D Phenomenoscope synchronization frame can be inserted into the motion picture. When the processor of the digital projector identifies the synchronization frame, it takes appropriate action to control the 3D Phenomenoscope spectacles, but may eliminate the synchronization frame from being projected or displayed to the user. Another means is to ‘watermark’ the identification of the synchronization event into the frame of the video so it is indistinguishable to the viewer. In this case, the video sensor of the 3D Phenomenoscope records the image, and processes it to identification the synchronization messages within the motion picture and take appropriate control actions. Watermarking may be achieved, for instance by stamping a code in the upper right hand part of the film in a single color. Video filters on the video sensor of the 3D Phenomenoscope can then eliminate all but that watermark color prior to intelligent processing by the processor of the 3D Phenomenoscope to identify the 3D Phenomenoscope synchronization event. [0180] In some embodiments, one may choose to exploit purposeful mismatching of Pulfrich 3D screen action direction and lens darkening. Spectacular cost-free special effects are to be mined from the phenomenon called pseudo-stereopsis which is usually an error in mounting stereo photo-pairs, so that each eye is channeled the perspective meant for the other eye. As mentioned, positive (solid) space will appear as negative (open), rear objects may appear forward of front objects. In an image of two suburban houses with a space of open sky visible between them, the sky will appear forward and solid, the house recessed openings, like caves, imbedded in the sky. [0181] Equipment [0182] Other embodiments of the invention may have more complex equipment with higher pixel resolutions, more than four lens states, and more complex controller algorithms. These other embodiments would still operate on the same principle—glasses that have a digital sensor, computer processor with a synchronization and control algorithm running on the computer processor that can identify synchronization events from processing the successive recorded images of the motion picture, and use that control information to control the state of the glass lenses. [0183] Other embodiments of the 3-D Phenomenoscope may use other material that can be controlled to change state and partially occlude or entirely clear the lenses of the viewer glasses. In other embodiments the pixel resolution of the digital sensor may be much denser than that specified in the preferred embodiment. And in other embodiments of the invention, other types of digital sensors may be used that can capture images of the motion picture and convert them to a digital representation for processing by the computer processor of the 3-D Phenomenoscope. [0184] The preferred embodiment of the invention uses LCD for the lens materials. Other embodiments of the Pulfrich Filter Spectacles may use other material that can be controlled to change state and partially occlude or entirely clears the lenses of the viewer glasses. Such materials include, but are not limited to suspended particle materials, and electrochromic materials—both of which allow varying levels of transparency dependent on the applied electric charge. Electrochromic materials darken when voltage is added and are transparent when voltage is taken away. [0185] In other embodiments the viewing glasses may include power on/off switches, and/or switches to override the operation of the glasses—e.g. by causing them to stay in the clear state and ignore the detected synchronization information. In other embodiments the 3-D Phenomenoscope may have switches to override the detected synchronization information, and place the viewer glasses in a state for left-to-right lateral motion (clear-dark), or for right-to-left lateral motion (dark-clear). [0186] In other embodiments there may be buttons on the goggles to allow the user to override and control the operation of the goggles. This includes, turning on and off the goggles, controlling the shading of the lenses. For viewer glasses that can take a multiplicity of shades of darkness, this would allow the viewer to control to some extent the extent to which they view the 3-dimensional effect. [0187] In still another embodiment, rather than one clear and one darkened lens, the invention uses two darkened lenses of different intensities. [0188] In another embodiment, the lens control algorithm of the 3-D Phenomenoscope can be disabled, and synchronization user-controlled. In still another embodiment the lens control algorithm is operational, but can be overridden by user controls, for instance by a hand actuated switch. [0189] In yet another embodiment, the functional equivalent of the glass lens controller unit (GLCU) is contained within a detached device, preferably a commonly used portable consumer device such as a cell phone. Cell phones are already commonly equipped with telephone and Internet access, have memory, power supply, LCD display, buttons to enter information (or touch screens), picture or motion picture sensor, processor, operating systems such as Palm OS, or Windows Mobile 2003 OS, (some cell phones have large volume disk storage) and wired or wireless means (e.g. bluetooth) that can be used to connect to the 3D Phenomenoscope. In such an embodiment, a stand is provided so that the cell phone can be positioned with the motion picture sensors aimed at the motion picture screen, and the program to run the synchronization events and operate the synchronization of the 3D Phenomenoscope lenses is running on the cell phone. The program records and processes the video, and determines synchronization events that are then communicated to control the 3D Phenomenoscope by wired or wireless means. Because of the more powerful processing power of the controller in cell phones than can be accommodated as part of the 3D Phenomenoscope spectacles, more powerful algorithms can be run on the cell phone than could be provided by the controllers contained within the 3D Phenomenoscope spectacles. [0190] Visual Effects [0191] In another embodiment of the invention, other types of screen motion can benefit from the 3D Pulfrich illusions, for example for viewing traveling-camera shots. As the camera moves forwards, screen movement moves both left and right outward from the screen center. This could be detected, and in another embodiment of the 3D Phenomenoscope, each lens could half-darken split along their centers, to the left of the left lens, and to the right of the right lens. Similarly when viewing the scene where the camera retreated in space, and screen movement simultaneously appeared from both sides toward the center, center-halves of each spectacle would simultaneously darken. [0192] In still other embodiments, other visual effects, such as secret coding and messages, could be implemented. In these embodiments of ‘decoder glasses’ special lens configurations, such as left-lens/right lens of Red/Red or any identical color may be used for decoding secret messages. [0193] Another preferred embodiment would allow the viewing of actual 3-dimensional displays in order to exaggerate or produce uncanny depth effects. For instance a use might be for stage effects such as advertising displays or motion-based artworks for display in museums and galleries. [0194] While preferred embodiments of the invention have been described and illustrated, it should be apparent that many modifications to the embodiments and implementations of the invention can be made without departing from the spirit or scope of the invention.

This invention discloses a 3-D Phenomenoscope through which any 2-dimensional motion picture with passages of horizontal screen movement can be viewed with a 3-dimensional visual effect. The 3-dimensional visual effect is produced by the 3-D Phenomenoscope regardless of whether the motion picture was shot on regular or digital film; regardless of whether the presentation media is film, digital film, VCR tape, or DVD, and; regardless of whether the motion picture is viewed in the movie theater, home TV, Cable TV, or on a PC monitor. No special processing during production or showing of a motion picture is required to achieve the visual effect of the 3-D Phenomenoscope—so no new constraints are placed on the owner, producer, distributor, or projectionist in creating, distributing or displaying motion pictures. The 3-D Phenomenoscope are completely self-contained computer-actuated battery-powered spectacles or glasses that a viewer wears when watching a motion picture. When the 3-D Phenomenoscope glasses are activated the viewer will see lateral motion in a motion picture in 3-dimensions. When the 3-D Phenomenoscope is not activated or the glasses are turned off, or if the viewer is not wearing the 3-D Phenomenoscope glasses, then the viewer will see the motion picture unchanged and without any special effects. The preferred embodiment of the invention presents a method and system for a 3-D Phenomenoscope to view 3-dimensional special effects in motion pictures, and disclose a system by which ordinary 2-dimensional motion pictures can be viewed as a 3-dimensionsal experience. The 3-D Phenomenoscope achieves this by taking advantage of the well-known Pulfrich effect, by which passages of lateral motion of an ordinary motion picture will appear to the viewer in 3-Dimensions if the motion picture is viewed through right and left lenses that are configured with a clear lens and a light-reducing or darker lens. Ordinary eyeglasses are configured with: (a) Right and left lenses for which the degree of clarity or darkening of the lens can be individually controlled (b) Digital photo sensors (a digital camera) that can capture the viewed motion picture as successive images and convert the captured frames to digital images for processing (c) Computer processor to process the successive images and identify lateral motion synchronization events, and (d) Ability to provide individual control for the light-reduction or darkening of the right or left lens based on the identified synchronization events. In this way, the 3-D Phenomenoscope provides a fully self-contained apparatus that allow any motion picture to be viewed with the visual effect of 3-dimensions.

big_patent

FIELD OF THE INVENTION The present invention relates generally to the dicing of semiconductor devices, and more particularly, to an apparatus and method for the dicing of semiconductor wafers using pressure to mechanically separate the individual die from the wafer. BACKGROUND OF THE INVENTION Semiconductor die are typically fabricated in wafer form. Using well known semiconductor fabrication techniques, a wafer undergoes a series of processing steps, such as deposition, masking, etching, implanting, doping, metallization, etc. to form complex integrated circuits on individual die on the wafer. Currently, several hundred to tens of thousands of die may be fabricated on a single wafer. Use of a dicing machine is the common manner in which the individual die are singulated from the wafer. During dicing, the wafer is placed onto a cutting platform. A saw is then used to cut the wafer along the scribe lines, sometimes referred to as “saw streets”, which run in the X and Y direction on the wafer and separate the individual dice. After all the saw streets have been cut, the individual die on the wafer are singulated. There are a number of problems associated with the use of a wafer saw for dicing a semiconductor wafer. The process is relatively slow since each scribe line on the wafer is cut one at a time. On wafers with thousands of die and dozens or hundreds of scribe lines, the amount of time required to singulate all the die on the wafer may be significant. Maintenance of the wafer saw is also a problem. The machine periodically needs to be serviced and repaired. The cutting blade also needs to be replaced periodically. During the maintenance and repair, the machine cannot be used, reducing the overall throughput and efficiency of the wafer singulation operation. Another issue with using wafer saws is that as the thickness of wafers become thinner and thinner, the wafers tend to chip along the cutting edge. This chipping is problematic because it may damage or destroy otherwise functional die on the wafer, thereby reducing yields. An apparatus and method for the dicing of semiconductor wafers using pressure to mechanically separate the individual die from the wafer without the use of a wafer saw is therefore needed. SUMMARY OF INVENTION To achieve the foregoing, and in accordance with the purpose of the present invention, a method and apparatus for the dicing of semiconductor wafers using pressure to mechanically separate the individual die from the wafer without the use of a wafer saw is disclosed. The method includes forming trenches along the scribe lines on a semiconductor wafer and then applying a mechanical pressure to the semiconductor wafer. The mechanical pressure causes a “clean break” of the wafer along the scribe lines, thereby singulating individual die on the wafer. The apparatus comprises a pad for supporting a semiconductor wafer and a positioning member to position the semiconductor wafer on the pad. A pressure mechanism is provided to apply a mechanical pressure to the wafer so as to singulate the individual die on the wafer. BRIEF DESCRIPTION OF THE DRAWINGS The invention, together with further advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying drawings in which: FIG. 1 is a diagram of semiconductor wafer. FIGS. 2A through 2G are a series of cross sections of a semiconductor wafer undergoing the wafer singulation process according to the present invention. FIGS. 3A and 3B are a diagrams illustrating of a ring used to support the wafer during singulation according to the present invention. FIG. 4 is a flow diagram illustrating the method of the present invention. In the figures, like reference numbers refer to like components and elements. DETAILED DESCRIPTION OF THE INVENTION Referring to FIG. 1 , a diagram of semiconductor wafer is shown. The wafer 10 includes a plurality of die 12 fabricated thereon. Horizontal and vertical scribe lines 14 separate each of the die 12 on the wafer 10 . After the individual die 12 wafer have been fabricated and probed, the individual die 12 are singulated as described below. Referring to FIGS. 2A through 2G are a series of cross sections of a semiconductor wafer 10 undergoing the wafer singulation according to the present invention. In FIG. 2A , the cross section of the wafer 10 is shown. Although not visible in this view, the individual die are fabricated on the top surface of the wafer 10 . In FIG. 2B , a photo resist layer 20 is applied across the top surface of the wafer 10 . In one embodiment, the photo resist layer 20 is Silicon Nitride (S1N4) that is spun onto the surface of the wafer 10 . The thickness of the photo resist layer 20 may range from 2 to 5 microns. The purpose of the photo resist layer 20 is to protect the underlying metallization and circuitry on the surface of the wafer 10 . In FIG. 2C , the photo resist layer 20 is patterned using standard photolithography techniques to form openings 22 over the scribe lines 14 on the surface of the wafer 10 . The surface of the wafer 10 is thus exposed through the openings 22 . Although not visible in FIG. 2C , it should be appreciated that the openings 22 run the entire length of the horizontal and vertical scribe lines 14 on the surface of the wafer 10 . In FIG. 2D , the patterned wafer undergoes an etch to form trenches 24 along the horizontal and vertical scribe lines 14 on the wafer surface. As is well known in the semiconductor fabrication art, the portions of the photo resist layer 20 left intact after patterning protects the underlying circuitry and metallization. The exposed portions of the wafer 10 as defined by the openings 22 in the photo resist layer, however, allow the underlying silicon of the wafer 10 to be etched away. In various embodiments of the invention, the depth of the trenches may vary from approximately ten percent to fifty percent of the thickness of the wafer 10 . For example, for a wafer that is approximately 800 microns thick, the depth of the trenches 24 may range from 150 to 200 microns. It should be noted that this example should in no way be construed as limiting the invention. The depth of the trenches 24 may be greater or less than the 150 to 200 microns and may range as a total percentage of the overall thickness of the wafer from less than ten percent to more than fifty percent. The wafer 10 can also be etched using any of a number of well known techniques, for example a plasma etch or a wet etch. After the etch is performed, the photo resist layer 22 is removed using standard semiconductor processing techniques. In an optional processing step as illustrated in FIG. 2E , the wafer 10 is back-grinded to reduce its overall thickness. In one embodiment for example, the 800 micron thick wafer 10 is back-grinded to a thickness of 300 to 200 microns. Again, this thickness range is only exemplary and should not be construed as limiting the invention in anyway. Generally speaking, the final thickness of the wafer 10 is largely dictated by the application of the die. With cell phones or any other application where small size and portability is desirable, generally the thinner the die the better. The thickness of the wafer 10 may be reduced further for example to 50 or less microns thick. In embodiments where the wafer 10 is going to be back-grinded, the depth of the trenches must be determined accordingly. For example, if a wafer is going to be back-grinded to a thickness of 200 microns, then the appropriate depth of the trenches 24 may be 50 to 100 microns. It should be noted that the back-grinding is optional and is not a required step in the practice of the present invention. It should be understood that as semiconductor processing and handling technology improves in the future, it is generally expected that the thickness of wafers after back-grinding will become thinner and thinner. According to the spirit of the present invention, the type and duration of the etch used to form the trenches 24 during etching are dictated so that the final depth of the trenches 24 equals the desired percentage of the overall thickness of the wafer 10 after back-grinding. Referring to FIG. 2F , a layer of adhesive tape 26 is applied to the back-surface of the wafer 10 . In one embodiment, the tape 26 is standard wafer dicing tape such as “Nitto” tape commonly used in semiconductor process and handling, from the Nitto Denko Company of Japan. Referring to FIG. 2G , the wafer 10 is placed active-surface down onto a soft pad 28 . Mechanical pressure is then applied to the back surface 30 of the wafer 10 . In various embodiments of the invention, the pressure may be applied in the X direction and the Y direction to cause the wafer to break along the horizontal and vertical scribes lines 14 respectively. In an alternative embodiment, pressure in a circular direction over the back surface 30 of the wafer 10 may also be applied. The applied pressure causes a “clean break” along the trenches 24 , thus singulating the dice 12 on the wafer 10 . The mechanism used to apply the pressure may include but is not limited to a roller, a blade, “squeegee” or a roller. FIG. 3A is a top-down diagram illustrating a ring used to hold the wafer in place during singulation. The ring 32 has the same general shape and is placed around the circumference of the wafer 10 . The wafer is placed, with its active surface facing down, onto pad 28 (not visible in FIG. 3A ). The adhesive tape, denoted by lines 26 , is visible on the back surface of the wafer through the ring 32 . FIG. 3B is a cross section of the ring 32 and the wafer 10 . As illustrated, the wafer 10 rests on pad 28 . The ring 32 is provided around the circumference of the wafer 10 . The tape 28 is provided on the back or non-active surface of the wafer 10 . During singulation, pressure is applied to the back surface of the wafer 10 . In various embodiments, the pressure is applied in the X and the Y directions across the back surface of the wafer 10 to cause the wafer to break along the horizontal and vertical scribe lines 14 respectively. In an alternative or additional embodiment, pressure may be applied in a circular motion around the wafer 10 , as illustrated by the curved arrow 34 illustrated in FIG. 3A . FIG. 4 is a flow diagram 50 illustrating the sequence of the present invention. In the initial step, the circuitry and metallization are fabricated on the active surface of the wafer 10 (box 52 ). The photo resist layer 20 is then applied across the active surface of the wafer 10 (box 54 ) and then patterned (box 56 ) to form openings running the length of the horizontal and vertical scribe lines 14 on the wafer 10 . Trenches 24 are then etched (box 58 ) in the openings along the horizontal and vertical scribe lines 14 . An adhesive tape is then placed on the back-surface of the wafer (box 60 ). Pressure is next applied to the back surface causing the wafer 10 to break along the trenches 24 in the horizontal and vertical scribe lines, thereby singulating the dice 12 from the wafer 10 . Although the foregoing invention has been described in some detail for purposes of clarity of understanding, it will be apparent that certain changes and modifications may be practiced within the scope of the appended claims. For example, the present invention. may be used any sized wafer or any type of die, such as memory, logic, analog, microprocessor, MOS, bipolar, or any other type of semiconductor chip. Alternatively, the trenches may be formed by a partially cutting the wafer using a wafer saw to the desired depth instead of performing an etch. Similarly, the trenches could be formed on the bottom or non-active surface of the wafer. Therefore, the described embodiments should be taken as illustrative and not restrictive, and the invention should not be limited to the details given herein but should be defined by the following claims and their full scope of equivalents.

A method and apparatus for the dicing of semiconductor wafers using pressure to mechanically separate the individual die from the wafer without the use of a wafer saw. The method includes forming trenches along the scribe lines on a semiconductor wafer and then applying a mechanical pressure to the semiconductor wafer. The mechanical pressure causes a “clean break” of the wafer along the scribe lines, thereby singulating individual die on the wafer. The apparatus comprises a pad for supporting a semiconductor wafer and a positioning member to position the semiconductor wafer on the pad. A pressure mechanism is provided to apply a mechanical pressure to the wafer so as to singulate the individual die on the wafer.

big_patent

BACKGROUND [0001] 1. Field of the Invention [0002] The present invention generally relates to field emission display panels or devices, and more particularly, relates to a field emission display device having at least one reduction plate or electrode which deflects ionic emission gas away from the field emission components of the device to prevent damage to the field emission components. [0003] 2. Background of the Invention [0004] In recent years, flat panel display devices have been developed and used in electronic applications such as personal computers. One of the popularly-used flat panel display devices is an active matrix liquid crystal display which provides improved resolution. However, liquid crystal display devices have many inherent limitations that render them unsuitable for a number of applications. For instance, liquid crystal displays have numerous fabrication limitations including a slow deposition process for coating a glass panel with amorphous silicon, high manufacturing complexity and low yield. Moreover, the liquid crystal display devices require a fluorescent back light which draws high power while most of the light generated is wasted. A liquid crystal display image may be difficult to see under bright light conditions or at wide viewing angles which further limit its use in many applications. [0005] Other flat panel display devices have been developed in recent years to replace the liquid crystal display panels. One of such devices is a field emission display device that overcomes some of the limitations of LCD and provides significant advantages over the traditional LCD devices. For instance, the field emission display devices have higher contrast ratio, larger viewing angle, higher maximum brightness, lower power consumption and a wider operating temperature range when compared to conventional thin film transistor (TFT) liquid crystal display panels. [0006] A most drastic difference between an FED and an LCD is that, unlike the LCD, the FED utilizes colored phosphors to produce its own light. The FEDs do not require complicated, power-consuming back lights and filters and, as a result, almost all the light generated by an FED is visible to the user. Moreover, the FEDs do not require large arrays of thin film transistors, and thus, a major source of high cost and yield problems for active matrix LCDs is eliminated. [0007] In an FED, electrons are emitted from a cathode and impinge on phosphors coated on the back of a transparent cover plate to produce an image. Such a cathodoluminescent process is known as one of the most efficient methods for generating light. In contrast to a conventional CRT device, each pixel or emission unit in an FED has its own electron source, i.e., typically an array of emitting microtips. A voltage difference exists between a cathode and a gate electrode which extracts electrons from the cathode and accelerates them toward the phosphor coating. The emission current, and thus, the display brightness, is strongly dependent on the work function of the emitting material. To achieve the necessary efficiency of an FED, the cleanliness and uniformity of the emitter source material are very important. [0008] In order for electrons to travel in an FED, most FEDs are evacuated to a low pressure such as 10 −7 torr in order to provide a log mean free path for the emitted electrons and to prevent contamination and deterioration of the microtips. The resolution of the display can be improved by using a focus grid to collimate electrons drawn from the microtips. [0009] In the early development for field emission cathodes, a metal microtip emitter of molybdenum was utilized. In such a device, a silicon wafer is first oxidized to produce a thick silicon oxide layer and then a metallic gate layer is deposited on top of the oxide. The metallic gate layer is then patterned to form gate openings, while subsequent etching of the silicon oxide underneath the openings undercuts the gate and creates a well. A sacrificial material layer such as nickel is deposited to prevent deposition of nickel into the emitter wall. Molybdenum is then deposited at normal incidence such that a cone with a sharp point grows inside the cavity until the opening closes there above. An emitter cone is left when the sacrificial layer of nickel is removed. [0010] In an alternative design, silicon microtip emitters are produced by first conducting a thermal oxidation on silicon, followed by patterning the oxide and selectively etching to form silicon tips. Further oxidation or etching protects the silicon and sharpens the point to provide a sacrificial layer. In another alternate design, the microtips are built onto a substrate of a desirable material such as glass, as an ideal substrate for large area flat panel displays. The microtips can be formed of conducting materials such as metals or doped semi-conducting materials. In this alternate design for a FED device, an interlayer that has controlled conductivity deposited between the cathode and the microtips is highly desirable. A proper resistivity of the interlayer enables the device to operate in a stable condition. In fabricating such FED devices, it is therefore desirable to deposit an amorphous silicon film which has electrical conductivity in an intermediate range between that of intrinsic amorphous silicon and n + doped amorphous silicon. The conductivity of the n + doped amorphous silicon can be controlled by adjusting the amount of phosphorous atoms contained in the film. [0011] Generally, in the fabrication of an FED device, the device is contained in a cavity of very low pressure such that the emission of electrons is not impeded. For instance, a low pressure of 10 −7 torr is normally required. In order to prevent the collapse of two relatively large glass panels which form the FED device, spacers must be used to support and provide proper spacing between the two panels. For instance, in conventional FED devices, glass spheres or glass crosses have been used for maintaining such spacings in FED devices. Elongated spacers have also been used for such purposes. [0012] FIG. 1A shows an enlarged cross-sectional view of a conventional field emission display device 10 . The FED device 10 is formed by depositing a resistive layer 12 of typically an amorphous silicon base film on a glass substrate 14 . An insulating layer 16 of a dielectric material and a metallic gate layer 18 are then deposited and formed together to provide metallic microtips 20 and a cathode structure 22 is covered by the resistive layer 12 and thus, a resistive but somewhat conductive amorphous silicon layer 12 underlies a highly insulating layer 16 which is formed of a dielectric material such as SiO 2 . It is important to be able to control the resistivity of the amorphous silicon layer 12 such that it is not overly resistive but yet, it will act as a limiting resistor to prevent excessive current flow if one of the microtips 20 shorts to the metal layer 18 . [0013] A completed FED structure 30 , including an anode 28 mounted on top of the structure 30 , is shown in FIG. 1B . It is to be noted, for simplicity, that the cathode layer 22 and the resistive layer 12 are shown as a single layer 22 for the cathode. The microtips 20 are formed to emit electrons 26 from the tips of the microtips 20 . The gate electrodes 18 are provided with a positive charge, while the anode 28 is provided with a higher positive charge. The anode 28 is formed by a glass plate 36 which is coated with phosphorous particles 32 . An intermittent conductive indium-tin-oxide (ITO) layer 34 may also be utilized to further improve the brightness of the phosphorous layer when bombarded by the electrons 26 . This is shown in a partial, enlarged cross-sectional view of FIG. 1C . The total thickness of the FED device is only about 2 mm, with vacuum pulled in-between the lower glass plate 14 and the upper glass plate 36 sealed by sidewall panels 38 (shown in FIG. 1B ). [0014] The conventional FED devices formed with microtips shown in FIGS. 1A-1C produce a flat panel display device of improved quality when compared to liquid crystal display devices. However, a major disadvantage of the microtip FED device is the complicated processing steps that must be used to fabricate the device. For instance, the formation of the various layers in the device, and specifically, the formation of the microtips, requires a thin film deposition technique that utilizes a photolithographic method. As a result, numerous photomasking steps must be performed in order to define and fabricate the various structural features in the FED. The CVD deposition processes and the photolithographic processes involved greatly increase the manufacturing cost of an FED device. [0015] In a co-pending application Ser. No. 09/377,315, filed Aug. 19, 1999, assigned to the common assignee of the present invention, a field emission display device and a method for fabricating such device of a triode structure using nanotube emitters as the electron emission sources were disclosed. In the triode structure FED device, the device is constructed by a first electrically insulating plate, a cathode formed on the first electrically insulating plate by a material that includes metal, a layer formed on the cathode of a high electrical resistivity material, a layer of nanotube emitters formed on the resistivity layer of a material of carbon, diamond or diamond-like carbon wherein the cathode, the resistivity layer and the nanotube emitter layer form an emitter stack insulated by an insulating rib section from adjacent emitter stacks, a dielectric material layer perpendicularly overlying a multiplicity of the emitter stacks, a gate electrode on top of the dielectric material layer, and an anode formed on a second electrically insulating plate overlying the gate electrode. The FED device proposed can be fabricated advantageously by a thick film printing technique at substantially lower fabrication cost and higher fabrication efficiency than the FEDs utilizing microtips. [0016] In another co-pending application Ser. No. 09/396,536, filed Sep. 15, 1999, assigned to the common assignee of the present invention, a field effect emission display device and a method for fabricating the diode structure device using nanotube emitters as the electron emission sources were disclosed. In the diode structure FED device, the device is constructed by a first glass plate that has a plurality of emitter stacks formed on a top surface. Each of the emitter stacks is formed parallel to a transverse direction of the glass plate and includes a layer of electrically conductive material such as silver paste and a layer of nanotube emitter on top. The first glass plate has a plurality of rib sections formed of an insulating material in-between the plurality of emitter stacks to provide electrical insulation. A second glass plate is positioned over and spaced-apart from the first glass plate with an inside surface coated with a layer of an electrically conductive material such as indium-tin-oxide. A multiplicity of fluorescent powder coating strips is then formed on the ITO layer each for emitting a red, green or blue light when activated by electrons emitted from the plurality of emitter stacks. The field emission display panel is assembled together by a number of side panels that join the peripheries of the first and second glass plate together to form a vacuum-tight cavity therein. [0017] FIGS. 2A and 2B show a schematic view of a conventional FED device 40 . The FED device 40 includes a cathode 42 which is spaced from an anode 46 . Multiple field emission elements 44 are provided in electrical contact with the cathode 42 for emitting electrons 52 toward the anode 46 . A voltage source 48 is provided to apply a voltage potential which establishes an electric field 50 between the cathode 42 and the anode 46 . [0018] During operation of the FED device 40 , oxygen and nitrogen are typically present at low pressures between the cathode 42 and the anode 46 . When the FED device 40 is energized, a voltage potential is applied by the voltage source 48 , between the cathode 42 and the anode 46 , to establish the electric field 50 . High-energy electrons 52 are emitted from the field emission elements 44 , toward the anode 46 . These high-energy electrons 52 strike the nitrogen and oxygen gas and form positive nitrogen and oxygen ions, as shown in FIG. 2B . The nitrogen and oxygen ions discharge to the cathode 42 , causing a surge of the electrical current passing to the cathode 42 and field emission elements 44 . This magnified electrical current tends to burn and damage the field emission elements 44 . Accordingly, a protection structure is needed for deflecting a discharge path of ionized gases away from a cathode in an FED device to prevent electrical surging and burn-out damage to field emission elements in the device. BRIEF SUMMARY OF THE INVENTION [0019] An object of the present invention is to provide a novel protection structure for preventing burn-out damage to field emission elements in a field emission display device. [0020] Another object of the present invention is to provide a novel field emission display device provided with a protection structure having at least one reduction plate or electrode for altering the discharge path of ionized gases and preventing the gases from inducing an electrical surge which may otherwise cause burnout damage to field emission elements in the device. [0021] Still another object of the present invention is to provide a novel field emission display device having a protection structure which may include multiple reduction plates or electrodes interspersed among field emission elements on a cathode in the device to alter the discharge path of ionized gases in the device and prevent current-induced burnout damage to the field emission elements. [0022] A still further object of the present invention is to provide a novel field emission display device which includes a protection structure that substantially prolongs the lifetime of field emission elements in the device. [0023] Another object of the present invention is to provide a novel field emission display device having a protection structure which may include multiple, elongated reduction plates or electrodes that run parallel to and between rows of field emission elements in the device. [0024] Yet another object of the present invention is to provide a novel field emission display device having a protection structure that is arranged in a meshwork- or net-shaped configuration among field emission elements in the device. [0025] In accordance with these and other objects and advantages, the present invention is generally directed to a novel protection structure for protecting field emission elements in a field emission display device from burnout damage due to electrical current surges induced to the device cathode by ionized gases in the device. [0026] The structure includes one or multiple reduction plates or electrodes which are typically provided on the cathode. A voltage source is electrically connected to the reduction plate or plates to alter the discharge path of the ionized gases from the device cathode to the reduction plate or plates. Consequently, induction of electrical current surges to the cathode is avoided, thereby preventing burnout damage to the field emission elements. [0027] In a typical embodiment of the invention, multiple reduction plates or electrodes are interspersed among the field emission elements in the device. In one embodiment, the multiple reduction plates or electrodes are elongated and run parallel and adjacent to rows of field emission elements in the device. In another embodiment, the multiple reduction plates or electrodes are arranged in a meshwork- or net-shaped configuration among the field emission elements in the device. BRIEF DESCRIPTION OF THE DRAWINGS [0028] FIG. 1A is an enlarged, cross-sectional view of a cathode and field emission element structure of a conventional field emission display device; [0029] FIG. 1B is a cross-sectional view of a complete conventional field emission display device structure; [0030] FIG. 1C is a cross-sectional view of a conventional field emission display device, illustrating electron bombardment of a conductive layer on the anode of the device; [0031] FIG. 2A is a schematic of a conventional field emission display device, illustrating ionization of oxygen and nitrogen gas in the device by high-energy electrons emitted by the field emission elements; [0032] FIG. 2B is a schematic of the conventional field emission display device, as shown in FIG. 2A , illustrating discharge of oxygen and nitrogen ions to the cathode of the device; [0033] FIG. 3 is a schematic of a field emission display device of the present invention, illustrating discharge of positive oxygen and nitrogen ions to a negatively-charged reduction plate or electrode; [0034] FIG. 4 is a perspective, partially schematic, view of one embodiment of the field emission display device of the present invention, illustrating elongated reduction plates or electrodes arranged parallel and adjacent to rows of field emission elements of the device; and [0035] FIG. 5 is a perspective, partially schematic, view of another embodiment of the field emission display device of the present invention, illustrating reduction plates or electrodes arranged in a meshwork- or net-shaped pattern among the field emission elements of the device. DETAILED DESCRIPTION OF THE INVENTION [0036] The present invention is directed to a field emission display device which includes a structure for deflecting the discharge path of gas ions away from a cathode. This prevents surges in electrical current from being drawn to the cathode and inducing burnout damage to field emission elements provided in electrical communication with the cathode. Consequently, the lifetime of the device is substantially prolonged. [0037] Referring initially to FIG. 3 , wherein a schematic of a field emission device 54 according to the present invention is shown. The field emission device 54 includes a cathode 56 provided in electrical communication with multiple field emission elements 58 . Each of the field emission elements 58 may be any type of dischargeable tip suitable for emitting high-energy electrons, such as carbon nanotubes, for example. An anode 60 is disposed in spaced-apart relationship to the cathode 56 and the field emission elements 58 . The cathode 56 and the anode 60 may be any electrically-conducting metal. An operating voltage source 62 is electrically connected to the cathode 56 and the anode 60 to establish an electric field 64 there between. [0038] In accordance with the present invention, a protection structure 68 includes at least one reduction plate or electrode 70 which is provided in the field emission device 54 , typically on the cathode 56 . The reduction plate 70 is preferably any electrically-conductive metal. An insulation layer 72 , which is an electrically-insulating material, typically separates the reduction plate 70 from the cathode 56 . A bias voltage source 74 is electrically connected to the reduction plate 70 for applying a negative voltage thereto, as hereinafter further described. [0039] In operation of the FED device 54 , the operating voltage source 62 applies an operating voltage potential of typically about 1000V between the cathode 56 and the anode 60 , to establish the electric field 64 . Simultaneously, the bias voltage source 74 applies a negative bias voltage of typically about −1 to −30 V to the reduction plate 70 . High-energy electrons 66 are emitted from the field emission elements 58 and strike a phosphors target (not shown) provided on the anode 60 , to emit light from the target. These high-energy electrons 66 , in transit from the field emission elements 58 to the target, strike molecular nitrogen and oxygen in the device 54 , thereby ejecting electrons from the nitrogen and oxygen and forming N + and O + ions. [0040] Due to the negative charge of the reduction plate 70 , applied by the bias voltage source 74 , the N + and O + ions are deflected away from the cathode 56 , along a gas discharge path 76 , to the reduction plate 70 . Accordingly, the N + and O + ions are prevented from contacting the cathode 56 , thereby preventing ion-induced surges in electrical current to the cathode 56 which would otherwise tend to damage the field emission elements 58 . At the reduction plate 70 , the N + and O + ions are reduced back to molecular nitrogen and oxygen as follows: N 2 + +e − →N 2 O 2 + +e−→O 2 [0041] A first exemplary structure of FED device according to the present invention is illustrated in FIG. 4 . As shown in FIG. 4 , a FED device 80 includes a cathode plate 81 having a plurality of elongated, parallel cathode strips 82 thereon, anodes 84 spaced-apart from the cathode plate 81 , and an operating voltage source 85 electrically connected to the cathode strips 82 and anodes 84 . Multiple, spaced-apart field emission elements 83 are provided on each of the cathode strips 82 . Each of the field emission elements 83 may be any type of dischargeable tip suitable for emitting high-energy electrons, such as carbon nanotubes, for example. [0042] A protection structure 87 of the FED device 80 includes multiple, elongated reduction plates or electrodes 89 that are provided on the cathode plate 81 . The reduction plates 89 extend parallel and adjacent to the cathode strips 82 on which the field emission elements 83 are provided. A bias voltage source 90 is electrically connected to each reduction plate 89 of the protection structure 87 for applying a negative bias voltage to the reduction plate 89 . Accordingly, the negative bias voltage applied by the bias voltage source 90 imparts a negative charge to the reduction plates 89 which attracts positive nitrogen and oxygen ions thereto and prevents current-induced damage to the field emission elements 83 , as heretofore described with respect to the protection structure 68 of FIG. 3 . [0043] The reduction plates 89 may be fabricated on the cathode plate 81 at the same as the cathode strips 82 . In manufacture, a metal material, i.e., the metal cathode plate 81 , is first deposited on a substrate (not shown), using conventional deposition techniques. Photolithography techniques are then used to form a first mask (not shown) which defines the location and geometry of the cathode strips 82 and the reduction plates 89 on the cathode plate 81 . The cathode plate 81 is then etched to form the cathode strips 82 and the reduction plates 89 according to the pattern defined by the first mask. A wet etching method may be used to precisely control the geometry and size of the cathode strips 82 . Next, a second mask (not shown) is formed on the cathode strips 82 and the reduction plates 89 to define the geometry and location of the field emission elements 83 on the cathode strips 82 , followed by etching and fabrication of the field emission elements 83 . In this structure, the reduction plates 89 and the cathode strips are formed on a same plane and are parallel and alternately spaced-apart. Each of the reduction plate 80 provides protection for its adjacent field emission elements 83 . [0044] In addition to the elongated and parallel structure described above, the reduction plates 89 can also be formed in a meshwork-shape or a net-shape according to another exemplary embodiment of the present invention, which is shown in FIG. 5 . As shown in FIG. 5 , an FED device 92 includes a cathode plate 93 ; multiple, elongated, parallel cathode strips 94 fabricated on the cathode plate 93 ; anodes 96 disposed in spaced-apart relationship to the cathode plate 93 ; and an operating voltage source 97 electrically connected to the cathode strip 94 and anodes 96 . Multiple field emission elements 95 are provided on each of the cathode strips 94 for emitting high-energy electrons toward the anode 96 . [0045] A meshwork-shaped or net-shaped protection structure 99 including reduction plates 101 is provided on the cathode plate 93 of the FED device. The reduction plates 101 are formed on the top of the cathode plate 93 and is separated from the cathode strips 94 by an insulation layer 100 . Accordingly, the reduction plates 101 along with the underlying insulation layer 100 impart a meshwork- or net-shaped configuration to the protection structure 99 . [0046] A bias voltage source 103 is electrically connected to the reduction plates 101 of the protection structure 99 . The bias voltage source 103 applies a negative voltage to the protection structure 99 to attract positive nitrogen and oxygen ions formed by the high-energy electrons emitted by the field emission elements 95 . This prevents the ions from contacting the cathode strips 94 and inducing surging of an excessive electrical current to the cathode strips 94 and field emission elements 95 , as heretofore described with respect to the FED device 54 of FIG. 3 . [0047] The manufacturing of the FED device 92 is described below. Initially, a first metal layer is deposited on a substrate (not shown) to form the cathode plate 93 . A first mask (not shown) is then patterned on the cathode plate 93 to etch the cathode strips 94 therein. After the first mask is removed from the cathode plate 93 , the insulator layer 100 is deposited over the cathode plate 93 and cathode strips 94 . Next, a second metal layer for the reduction plates 101 is deposited on the insulator layer 100 , followed by formation of a second mask (not shown) using a negative photoresist to define the geometry and location of the light emission elements 95 . The second metal layer is then etched away the region for forming the field emission elements 95 , leaving the reduction plates 101 . Afterward, keeping the second mask unremoved, the regions where the second metal layer is removed are then deposited with materials for the light emission elements 95 . After the light emission elements 95 are formed, the structure of the FED device 92 as shown in FIG. 5 is completed. [0048] The foregoing disclosure of the preferred embodiments of the present invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many variations and modifications of the embodiments described herein will be apparent to one of ordinary skill in the art in light of the above disclosure. The scope of the invention is to be defined only by the claims appended hereto, and by their equivalents. [0049] Further, in describing representative embodiments of the present invention, the specification may have presented the method and/or process of the present invention as a particular sequence of steps. However, to the extent that the method or process does not rely on the particular order of steps set forth herein, the method or process should not be limited to the particular sequence of steps described. As one of ordinary skill in the art would appreciate, other sequences of steps may be possible. Therefore, the particular order of the steps set forth in the specification should not be construed as limitations on the claims. In addition, the claims directed to the method and/or process of the present invention should not be limited to the performance of their steps in the order written, and one skilled in the art can readily appreciate that the sequences may be varied and still remain within the spirit and scope of the present invention.

A novel protection structure for protecting field emission elements in a field emission display device from burnout damage due to electrical current surges induced to the device cathode by ionized gases in the device. The protection structure includes one or multiple reduction plates or electrodes which are typically provided on the cathode. The reduction plate or plates are negatively-charged and attract positively charged gas ions. Consequently, induction of electrical current surges to the cathode is avoided, thereby preventing burnout damage to the field emission elements.

big_patent

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image sensor, and more particularly, to an image sensor which includes multiple imaging planes. 2. Description of the Prior Art Typical charge-coupled device (CCD) image sensors are formed on flat, circular semiconductor substrates known as wafers. Image sensor elements are fabricated on either a top or bottom surface of the wafer by means of various doping layers of several microns in depth. Upon completion of the image sensor elements, the die is cut from the wafer and mounted in a package where either the top or bottom surface is exposed for illumination. In U.S. Pat. No. 4,031,315, there is shown a CCD image sensor which comprises image sensor elements arranged in matrix form on one surface of the image sensor. In one embodiment, the image sensor can be irradiated on a top surface, and in a second embodiment, the substrate body is made sufficiently thin that the sensor can be irradiated on a bottom surface. There is a problem in using this image sensor in certain applications; for example, the sensor cannot be used in apparatus where it is desired to simultaneously image two opposing surfaces. In such an application, two separate image sensors must be used, and this adds to the expense and complexity of the apparatus. U.S. Pat. No. 4,665,420, discloses a CCD image sensor which is adapted to receive illumination on a top surface. In order to prevent the injection of undesirable charge carriers into the CCD registers, the image sensor includes a means of passivating the edges of the sensor. The image sensor includes a plurality of space detectors arranged in columns extending along one of the major surfaces of the sensor substrate. Between the edge of the substrate and the adjacent column of detectors, an edge drain is provided for receiving any charge carriers generated at the edge in order to prevent the charge carriers from being injected into the adjacent detectors. Although charge carriers are being collected in this image sensor from an edge of the sensor, there is no provision for using the charge carriers to record information. Thus, the sensor can only be used to image in a single plane. SUMMARY OF THE INVENTION It is an object of the present invention to overcome the problems in the prior art discussed above by providing an image sensor in which information can be recorded through an edge surface of the sensor. In accordance with one aspect of the present invention, there is provided an image sensor comprising: a semiconductor substrate of a first conductivity type, the substrate having opposed major surfaces and opposed edges between the surfaces, one of the edges having a surface which is receptive to light; an image sensor element formed in the substrate and located adjacent the one edge, the image sensor element including a charge collection and transfer means and an image sensing region in which charge carriers are generated by light impinging on the surface of the one edge; and means in the substrate for guiding charge carriers in the image sensing region toward the charge collection and transfer means. In one embodiment of the present invention, an image sensor includes an elongated substrate of a P-type material. The image sensor includes an imaging plane on the top surface and imaging planes on two edge surfaces bordering the top surface. The substrate comprises a bottom layer which is highly doped with a P-type material and an upper layer which is more lightly doped with a P-type material. Three columns of image sensor elements are formed in the substrate. One column is adapted to function with the top imaging plane, and the other two columns are adapted to function with the two imaging planes on the edge surfaces. Each of the image sensor elements includes an image sensing region and a charge collection and transfer means which is a buried-channel CCD. The image sensor element which functions with the top imaging plane includes a photodiode in the image sensing region. A P + layer is formed in the top surface of the image sensor between each edge surface and the column of image sensor elements adjacent to the edge surface. The increased doping level in the P + layers on the top and bottom surfaces gives rise to a barrier to electron movement in the direction of the P + layers. Thus, charge carriers which are created as a result of light energy absorbed through the side edges of the sensor are effectively guided back toward the middle of the substrate where they will diffuse laterally toward the CCD's located along the two edges. A principal advantage of the present invention is that the image sensor can be used to image in a plurality of planes. This permits the sensor to be used in many image formats such as formats involving the simultaneous imaging of two opposing surfaces or the surface imaging of passageways. Detection of images through the edges is made possible by means of doped layers which create a waveguide-like structure adjacent the edges of the sensor. The present invention can be formed using processing techniques which are compatible with techniques used in forming other types of image sensors, and thus, the invention can be easily incorporated in various types of known image sensors. Other features and advantages will become apparent upon reference to the following description of the preferred embodiment when read in light of the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the image sensor of the present invention; FIG. 2 is sectional view, taken along the line 2--2 in FIG. 1; FIG. 3 is a sectional view, similar to FIG. 2, illustrating the potentials within the image sensor; FIG. 4 is an energy band diagram which illustrates the effect of the increased doping levels on electron movement; FIG. 5 is a cross-sectional view of a second embodiment of the present invention; and FIG. 6 is a perspective view illustrating one mounting arrangement for the image sensor of the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference to FIGS. 1 and 2, there is shown an image sensor 10 constructed in accordance with the present invention. Image sensor 10 comprises a P-type substrate 12 having major surfaces 11 and 19 and edge surfaces 26 and 28. Substrate 12 includes a highly doped bottom layer 15, labeled P + , and an upper layer 17 which is more lightly doped with a P-type material having a high carrier lifetime. Layer 17 can be fabricated, for example, by using known epitaxial growth techniques. Image sensor elements 14, 16, and 18, are formed in layer 17. Elements 14, 16, and 18 are arranged in rows, as shown in FIG. 2, and in columns along the length of image sensor 10. A P + layer 25 is formed between the image sensors 14 and 18 and substrate edges 28 and 26 respectively. As will be apparent from the discussion that follows, the thickness of layer 17 is important since it determines the effective vertical aperture dimension in edges 28 and 26 of the sensor 10. Common thicknesses for epitaxial layers range from 1-20 microns, and this range covers the range of dimensions needed for most CCD detectors. The carrier (electron) lifetime in the P + layers is low due to the doping level, and hence, these layers will not contribute significantly to the aperture. One suitable thickness for layer 17 is about 10 microns. Each of the image sensors includes an image sensing region and a charge collecting and transfer means. Image sensor element 16 includes photodiode 20 which functions as the image sensing region and is formed in layer 17 by an N-type region 21. The charge collecting and transfer means in sensor 16 is a buried-channel CCD 23 which is also formed by an N-type region 27. Image sensor element 16 further includes a storage gate 36, a transfer gate 38, and a clock phase terminal 40. Image sensors 14 and 18 are generally similar to each other, and their charge collecting and transfer means are spaced several microns from the edges 26 and 28 of sensor 10. Image sensor element 14 comprises an image sensing region 27, a buried-channel CCD 31 formed by an N-type region 33, a storage gate 30, a transfer gate 32, and a clock phase terminal 34. Image sensor element 18 comprises an image sensing region 29, a buried-channel CCD 35 formed by an N-type region 37, a storage gate 42, a transfer gate 44, and a clock phase terminal 46. As shown in FIG. 1, image sensor 10 has a first imaging plane 50 on edge 28, a second imaging plane 52 on a top surface of the sensor 10, and a third imaging plane 54 on edge 26 of the sensor. Image sensor element 16 functions in a conventional manner in response to illumination on plane 52. That is, photons λ impinging on imaging plane 52 will result in charge carriers "e" being collected in photodiode 20. When a voltage is supplied to transfer gate 38, the charge carriers are transferred to CCD 23 (see FIG. 3), and the charge carriers are shifted from the CCD 23 in a direction perpendicular to the surface to the drawing in FIG. 3 by means of clock terminal 40. Photons λ impinging on imaging planes 50 and 54 generate charge carriers in regions 27 and 29, respectively. The charge carriers are guided toward the CCD's 31 and 35 by the P + layers 15 and 25 which combine to form a type of electron waveguide in substrate 12. There is no local depletion region adjacent edges 26 and 28 so the carriers are not readily collected. Instead, the carriers are free to diffuse laterally. The effect of the P + layers in guiding the charge carriers is illustrated by the energy band diagram in FIG. 4 in which E c represents the conduction band energy level, E v is the valence band energy level, E i is the intrinsic energy level, and E f is the Fermi level. As demonstrated in FIG. 4, the increased doping level in layers 15 and 25 gives rise to a barrier to electron movement in the direction of these layers. Consequently, the carriers are effectively guided back, as indicated by arrow 39, toward the middle portion of substrate 12 where they will continue to diffuse laterally. Carriers which diffuse toward the edges 26 and 28 will be lost to recombination, but those which diffuse inward toward the CCD's 31 and 35 will eventually encounter the drift field from the storage gate depletion and be collected as signal charge. Since there is no patterning on the edges 26 and 28, the effective horizontal aperture on the edge surfaces is continuous. Pixel separation does not occur until the charge is collected within CCD storage regions 61. The probability of collection is highest in the storage region nearest the point of photon absorption. Charge carriers which are collected adjacent to edges 26 and 28 are transferred to CCD's 31 and 35 by means of voltages supplied to transfer gates 32 and 44, respectively. The carriers are shifted out of the CCD's 31 and 35 in a well-known manner by means of voltages supplied to clock phase terminals 34 and 46. A second embodiment of the present invention is shown in FIG. 5. Shown therein is an image sensor 10' in which elements similar to elements in image sensor 10 are identified with the same reference numeral with a prime added. Image sensor 10' is generally similar to sensor 10, except for CCD's 14' and 18' in which the lightly-doped N-type regions 37' and 33' have been extended to the edges 26' and 28', respectively. This structure effectively increases the lateral extent of the depletion region since the N-type region is coupled to the higher potential from the storage region. As a result, charge collection is improved and crosstalk is reduced. With reference to FIG. 6, there is shown a suitable mounting arrangement for image sensor 10. In order to avoid the interference of external connections on an imaging surface, bond pads 60 are shifted to ends 62 and 64 of the sensor 10. An opaque coating 66 can be applied on die edges 26 and 28 to prevent stray light from being absorbed on the die ends. Image sensor 10 is mounted on an insulated support block 70, and interconnects 71 on block 70 are used to make the connections between bond wires 72 and leads 74. An imaging lens 80 is indicated schematically for each of the imaging planes 50-54. It will be apparent that the image sensors 10 and 10' can be used in various applications. For example, the sensors could be used to simultaneously image a plurality of planes. Further, the concept of forming an imaging plane on an edge of a sensor can be used in an image sensor having any number of columns of image sensor elements on a top surface thereof. The image sensors of the present invention can also be used for color applications in which a red filter is placed over the image sensor elements in one imaging plane, a green filter covers the elements in a second imaging plane, and a blue filter covers the elements in a third imaging plane. In the use of a sensor with the color filters and suitable optics, a color document could be scanned in a single pass of the sensor. The invention has been described in detail with particular reference to the preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.

An image sensor is disclosed which comprises a plurality of image sensor elements arranged in rows and columns. Each of the image sesnor elements includes a a CCD. In order to provide an image sensor which can be used to image in different image formats, the image sensor includes imaging planes on edge surfaces as well as on a top surface. The top and bottom layers of the sensor are of an increased doping level, and these layers serve to guide charge carriers into CCD's located adjacent the edges of the sensor.

big_patent

[0001] This application claims the benefit of U.S. Provisional Application No. 60/664,620, filed Mar. 22, 2005, which is incorporated herein by reference in its entirety. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates generally to networks, and more specifically to home networks employing devices which incorporate power management systems. [0004] 2. Discussion of the Related Art [0005] Power management is desirable for home networks because a typical network appliance can consume several hundred watts of power per hour when it is turned on, whether or not it is performing its nominal, non-network functions. Such extraneous energy consumption can be quite expensive. [0006] Currently in home networks, a network master node must perform network administrative functions even when it is not performing its nominal, non-network functions. From an energy conservation standpoint, it is generally desirable for a device that is not performing its nominal device functions to enter into a power management (e.g., power save) mode. Indeed, Energy Star (EStar) guidelines, issued by the U.S. government's Environmental Protection Agency (EPA), require many home network devices to reduce their power consumption (e.g., to 1 watt or less) when they are not performing their nominal device functions. It is very difficult, however, for a network master node to enter into a power management mode while it is performing network administrative functions but not performing its own nominal device functions. As a result, the total energy consumption of conventional home networks undesirably tends to be the same regardless of whether or not the network master node is performing its own nominal device functions in addition to the network administrative functions. Thus, it would be advantageous to be able to turn a network master node off (or have it enter some power management mode) when the network master node is not performing its nominal device function to minimize total power consumption of the home network. [0007] Recently, it has been proposed to provide a network system wherein a network slave node will automatically “promote” itself to become a new network master node in the event that a network master node either fails to function properly or is taken off-line. In such a system, however, it is possible that devices on the home network other than the network slave node that promoted itself into the network master role may be more qualified to be a network master than the self-promoting device. As a result, such a network system may not be optimally administered. Moreover, if no network slave nodes are available to be promoted to the network master role, then the network is lost when the network master node enters either fails or goes off-line. [0008] Thus, it would be advantageous to minimize the total power consumption of a home network while ensuring that only the best qualified of available network slave nodes is promoted to the network master role, thereby continually maximizing the performance and administration of the home network and ensuring that the home network is not lost when the network master node enters into power save mode. SUMMARY OF THE INVENTION [0009] Several embodiments of the invention advantageously address the needs above as well as other needs by providing methods for transferring network administrative functions from a master device to a slave device. [0010] One embodiment can be characterized as a method of managing power consumption in a network including receiving an instruction for a first device in an active power state and serving as a network master node to enter into a power management state, the first device adapted to perform a network administrative function while in an active power state, the power management state having a lower power consumption than the active power state; sending data from the first device to a second device serving as a network slave node, the data enabling the second device to start performing the network administrative function while in an active power state; and placing the first device into the power management state after sending the data. [0011] Another embodiment can be characterized as a method of managing power consumption in a network including receiving a request to send data from a first device serving as a network master node to a second device serving as a network slave node, the data enabling a network administrative function to be performed, and the second device adapted to perform the network administrative function while in an active power state; sending a request reply from the second device to the first device, the request reply indicating acceptance of the request to send the data; and receiving the data at the second device. BRIEF DESCRIPTION OF THE DRAWINGS [0012] The above and other aspects, features and advantages of several embodiments of the present invention will be more apparent from the following more particular description thereof, presented in conjunction with the following drawings, wherein: [0013] FIG. 1 is a diagram exemplarily illustrating a home powerline network in accordance with one embodiment; [0014] FIG. 2 is a functional block diagram illustrating relationships between nodes of the network in accordance with several embodiments; [0015] FIG. 3 is a simplified flow diagram illustrating an operation of a network master node in accordance with one embodiment; [0016] FIG. 4 is a flow diagram illustrating a detailed operation of a network master node in accordance with one embodiment; [0017] FIG. 5 is a simplified flow diagram illustrating an operation of a network slave node in accordance with one embodiment; and [0018] FIG. 6 is a flow diagram illustrating a detailed operation of a network slave node in accordance with one embodiment. [0019] Corresponding reference characters indicate corresponding components throughout the several views of the drawings. Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions, sizing, and/or relative placement of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of various embodiments of the present invention. Also, common but well-understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments of the present invention. It will also be understood that the terms and expressions used herein have the ordinary meaning as is usually accorded to such terms and expressions by those skilled in the corresponding respective areas of inquiry and study except where other specific meanings have otherwise been set forth herein. DETAILED DESCRIPTION [0020] The following description is not to be taken in a limiting sense, but is made merely for the purpose of describing the general principles of exemplary embodiments. The scope of the invention should be determined with reference to the claims. [0021] Referring to FIG. 1 , a home network according to principles of several embodiments of the present invention includes a plurality of devices (e.g., a video server 100 , an audio server 102 , a video system 104 , and an audio system 106 ) communicatively coupled to each other via a network medium 108 and each capable of performing specific nominal device functions. [0022] A nominal device function of the video server 100 includes, for example, the ability to stream video and audio data to the video system 104 (e.g., provided as a television set) that has a nominal device function including, for example, the ability to communicate sound and images to a user. Similarly, a nominal device function of the audio server 102 includes, for example, the ability to stream audio data to the audio system 106 (e.g., provided as a stereo) that has a nominal device function including, for example, the ability to communicate sound to a user. [0023] The network medium 108 is, for example, a powerline network, a wired or wireless network, a local area network, an Ethernet network, or a wireless network based upon the 802.11 standard. [0024] Referring to FIG. 2 , and in accordance with various embodiments, the home network is implemented as a master/slave network, wherein one or more or all of the devices coupled to the network medium 108 are capable of serving as a “network master node” while all of the devices coupled to the network medium 108 are capable of serving as a “network slave node.” For example, the aforementioned video server 100 and audio server 102 are capable serving as both network master and slave nodes while the video system 104 and audio system 106 are capable of serving only as network slave nodes. In one embodiment, only one of the devices coupled to the network medium 108 can actually serve as the network master node at any time. Each device capable of serving as both a network master and slave node includes a master/slave (M/S) device-network-interface (DNI) 200 , a device manager 202 , and a power manager 204 . Each device capable of serving only as a network slave node includes a slave DNI 206 in addition to the aforementioned device and power managers 202 and 204 , respectively. [0025] Within the context of the illustrated home network, the network master node performs network administrative functions in addition to its nominal device functions. Network administrative functions are those that enable a network master node to control the transmission of data over the network medium 108 , and to instruct each network slave node coupled to the network medium 108 where to find another network slave node. For example, network administrative functions that a network master node can perform include beacon transmission (network access is based on beacon timing), device association and authentication, admission control, and bandwidth assignment and communication with other network master nodes in neighboring networks. In one embodiment, the network master node periodically broadcasts a beacon to each device serving as a network slave node. In one embodiment, the network master node performs device association and authentication by maintaining a list of devices registered on the network, if a new device is added, a device ID for the new device is provided to the network master node (e.g., by a user). In one the network master node manages all traffic on the network. Therefore, when a network slave node needs to begin streaming data, the network slave node must ask the network master node to assign enough network bandwidth to enable the data streaming. If enough bandwidth is available, the network master node assigns the necessary bandwidth to the particular network slave node. Accordingly, devices capable of serving as network master nodes must have sufficient processing power and memory to perform the aforementioned network administrative functions for the entire network. [0026] The M/S DNI 200 includes circuitry enabling a device serving as a network master node to perform the aforementioned network administrative functions as well as communicatively coupling the device manager 202 to other devices on the home network. In one embodiment, the device manager 202 controls the performance of nominal functions of its respective device. The power manager 204 of a particular device is coupled its respective device manager to manage the power consumption of its respective device. The slave DNI 206 essentially identical to the M/S DNI 200 except that the slave DNI 206 does not include circuitry enabling the device to perform the aforementioned network administrative functions. [0027] Referring next to FIG. 3 , a simplified flow diagram is shown illustrating an operation of a network master node in accordance with one embodiment. [0028] At step 301 , a device currently serving as a network master node (herein referred to as the “network master node”) receives instructions to enter into a power management mode (e.g., a power save mode). It will be appreciated that the network master node may be instructed to enter into the power save mode for any number of reasons (e.g., the particular device is no longer performing, has been instructed to stop performing, or no longer required to perform its nominal device functions). Subsequently, at step 303 , the network master node sends data enabling the aforementioned network administrative functions to be performed to a device currently serving as a network slave node (herein referred to as the “network slave node”). By sending the data from the network master node to the network slave node, the network administrative functions are conceptually transferred from the network master node to the network slave node. After the network administrative functions have been transferred, the master network node of step 301 enters into the power management state in step 305 and the network slave node that received the network administrative functions becomes the new network master node. By providing a means for transferring the network administrative functions from a network master node to a network slave node, the total power consumption of the home network may be minimized while ensuring that the administrative functions of the network are performed by another device. [0029] Referring next to FIG. 4 , a flow diagram is shown illustrating a detailed operation of a network master node in accordance with one embodiment. [0030] In operation, the process starts at step 400 . In step 401 , the network master node is instructed to enter into power save mode (e.g., a user presses a button). [0031] In step 402 , before entering into power save mode, the network master node determines if there is any traffic on the network medium 108 (e.g., the network master node determines if any network slave nodes are operating). If no traffic is found, the network master node enters power save mode in step 409 and the process ends at step 410 . If traffic is found, the network master node sends (e.g., broadcasts) a transfer request to the network slave nodes at step 403 . In one embodiment, the transfer request simply solicits any currently active devices to announce their ability to assume network master administrative functions. In another embodiment, the transfer request includes the network address of the current network master node. [0032] Next in step 404 , the network master node determines whether any network slave nodes have responded to the transfer request. In one embodiment, such a determination can be made by receiving a request reply message transmitted to the network master node by a slave network device. In one embodiment, the request reply message includes the network address of the accepting network slave node. When no network slave node has responded to the transfer request, the network master node waits for a predetermined period of time (e.g., about 500 ms, one minute, etc.) at step 405 and then returns to step 401 . When it is determined that the transfer request has initiated a response by the network slave nodes, the master device determines how many network slave nodes have responded in step 406 (e.g., by counting the number of request reply messages received). When the network master node determines that the transfer request has initiated a response by only one network slave node, the network master node sends data enabling the aforementioned network administrative functions to be performed to the sole responding network slave node (step 408 ). As discussed above, by sending the data from the network master node to the responding network slave node, the network administrative functions are conceptually transferred from the network master node to the network slave node. In one embodiment, the data includes any information that allows the network master node to perform the network administrative functions or includes an instruction for a network slave node to generate such information. For example, the data includes the list of registered devices, network addresses of the devices, bandwidth management information, time allocation information, etc. Subsequently, the master network node enters into power save mode in step 409 . [0033] When the master device determines that more than one network slave node has accepted the transfer request, the network master node selects a network slave node to transfer the network administrative functions to in step 407 . According to principles of many embodiments, the network master node selects a particular network slave node to transfer the network administrative functions to in accordance with predetermined selection criteria. In one embodiment, the selection criteria is based on the visibility of a particular network slave node on the network. In this case, the request reply messages transmitted by the network slave node further include the number of devices that that particular network slave node “sees” on the network medium 108 and can, therefore, communicate with. Accordingly, the master network device can select the network slave node that has the highest visibility of accepting network slave nodes on the network. [0034] In another embodiment, the selection criteria is based on the intelligence/functional capabilities of a particular network slave node on the network. In this case, the request reply messages transmitted by each network slave node further includes a vendor-assigned classification indicating how intelligent or functional that particular network slave node is. “Intelligence” represents processing power, speed, etc., while “functional capability” represents transmission bandwidth, speed, etc. Accordingly, the master network device can select the network slave node that has the highest intelligence or functional capabilities of accepting network slave nodes on the network. It will be appreciated, however, that the network master node can select a particular network slave node to transfer the network administrative functions to according to a combination of the aforementioned visibility- and intelligence/functional capability-based selection criteria. [0035] In yet another embodiment, the network master node can select a particular network slave node that has been specifically selected by a user to become the new network master node. [0036] After the master network device has selected the slave device in step 407 , the master network device transfers the network administrative functions to the selected slave network device in step 408 whereby the selected slave network device becomes the new master network device and the old master network device enters into power save mode in step 409 . The process ends at step 410 . [0037] According to the various embodiments of the present invention, the network administrative function is transferred to the slave network device while the slave network device is performing its own nominal device functions. In another embodiment however, the network administrative function is transferred to the slave network device intermittently with the network slave node's performance of its own nominal device functions. In yet another embodiment, the network administrative function is transferred to the slave network device after the network slave node has performed its own nominal device functions (e.g., when the nominal device functions include streaming audio/video information). [0038] Referring next to FIG. 5 , a simplified flow diagram is shown illustrating an operation of a network slave node in accordance with one embodiment. [0039] At step 501 , a device currently serving as a network slave node (herein referred to as the “network slave node”) receives a request to transfer a network administrative function from a device serving as a network master node for the network slave node to accept. Subsequently, at step 503 , the network slave node sends a request reply to the network master node, indicating that it will accept the transfer of the network administrative functions. Subsequently, at step 505 , the network slave node receives the transferred network administrative functions to become the new network master node. [0040] Referring next to FIG. 6 , a flow diagram is shown illustrating a detailed operation of a network slave node in accordance with one embodiment. [0041] In operation, the process starts at step 600 . In step 601 , the network slave node waits for a transfer request from a master network device. Upon receipt of a transfer request, the particular network slave node determines if it is in a power save mode at step 602 . Network slave nodes in power save mode do not accept transfer requests and, therefore, do not transmit request reply messages as discussed above. In such a case, the process ends at step 606 . When the particular network slave node is not in a power save mode (e.g., when the particular network slave node is performing its nominal device function), then the particular network slave node accepts the transfer request by transmitting request reply message to the master network device at step 603 . At step 604 , the slave network device then determines whether it has been selected by the master network device to be the new master network device. If the particular slave network device has not been selected by the master network device to be the new master network device, then the process ends at step 606 . If the particular slave network device has been selected by the master network device to be the new master network device, then the network administrative functions are transferred from the network master node to the particular slave network device at step 605 and the process ends at step 606 . In one embodiment, aforementioned selection and transfer process is completed within, for example, a few tens of milliseconds. If, for some reason, the network administrative functions are not transferred (e.g., because the current network master node is unplugged), then a suitable network slave node will self-promote itself to the network master node role. [0042] Generally, when any device coupled to the network medium 108 (including a previous master network device that has entered into power save mode) becomes activated (e.g., when a device is initially turned on or exits power save mode), it first checks for the presence of beacons on the network. When no beacon is found, the activated device concludes that there is no network master node on the home network, automatically becomes the network master node, generates information necessary to perform the aforementioned network administrative functions, and performs the aforementioned network administrative functions in addition to its nominal device function. However, when beacons are found on the network, the activated device simply becomes a network slave node and performs its nominal device functions. [0043] While the invention herein disclosed has been described by means of specific embodiments, examples and applications thereof, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope of the invention set forth in the claims.

A method, in accordance with one embodiment, of managing power consumption in a network, comprising receiving an instruction for a first device in an active power state and serving as a network master node to enter into a power management state, the network master node adapted to perform a network administrative function while in an active power state, the power management state having a lower power consumption than the active power state; sending data from the first device to a second device serving as a network slave node, the data enabling the second device to start performing the network administrative function while in an active power state; and placing the first device into the power management state after sending the data.

big_patent

BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to arrangements of antenna elements to measure the direction of propagation of electromagnetic radiation. 2. Related Art The directional properties of antennae and the processing of phase and amplitude information from separate antenna elements has long been used for determining the angle of arrival of signals, and thus determining the direction of the source transmitter. However, low elevation angles are difficult to measure because of interference from strong unquantifiable reflections from the ground. Moreover, radio direction finders and navigation systems are constrained by weather conditions, to use relatively low operating frequencies, where ground reflections cannot be excluded by the natural directivity of practical antennae. A unique equi-spaced triplet arrangement of similar antenna elements was identified in U.K. Patent No. 1449196 (incorporated herein by reference), which when placed orthogonal to a reflecting ground plane, could be used to determine a function of elevation angle which was independent of the unknown ground reflection coefficient. Patent No. 1449196 describes the use of a triplet to define fixed angles in the elevation plane, within which angle measurements were made by other means. This invention extends these ideas to optimize angle measurements, using the triplet itself, notably over selected sectors at low elevation angles. The prior art of UK 1449196 is illustrated in FIG. 1, which shows a single equi-spaced triplet for which the two R.F. outputs A+C and B are shown in the above patent to be; A+C=2f(a,p,r,h,P,θ)cos(2·II·d·sinθ/.lambda.) . . . (1) B=f(a,p,r,h,P,θ) . . . (2) Where: a represents the antenna element pattern. P represents the transmitted power. r represents the range to the transmitter. h represents the mid-height of the triplet. p represents the ground reflection coefficient. θ represents the elevation angle. d represents the spacing between triplet elements,; and λ represents the wavelength of the transmitted signal. The function f(..) represents the essential strength of the radio signal and is designated S. Whence, the quotient of (1) and (2) above is independent of a,p,r,h and P. The quotient of other functions of (1) and (2), for example the square or the modulus, is also independent of a,p,r,h, and P. The square of the signal amplitude is the natural output of a radio receiver, and takes only positive values, which is advantageous for post detection signal processing. At low elevation angles, p approximates to -1, and in this case S (representing the function (f)) simplifies to; S=f'(a,P,r)sin(2·II·h·sinθ/λ) . . . (3) so that h may be chosen to maximize the amplitude of S. Measurement of elevation angle can only be made, when S is non-zero, and is best made when S is changing slowly, with angle, near its maximum value. It will also be noted that when d =λ/2, (A+C)/2B takes values from 1 to -1 as the elevation angle changes over 90 degrees, typically, from the horizontal to the vertical. Larger values of d and other functions of (A+C)/2B may increase the sensitivity with which the elevation angle can be measured. However, for a single triplet, the angle measurement may become ambiguous over the angular range of interest. SUMMARY OF THE INVENTION It is one object or this invention to overcome such ambiguity. According to this invention, an antenna array for operation by radio interferometric techniques comprises; at least four antennae spaced so as to provide at least two equi-spaced linear triplets perpendicular to a ground plane, each triplet will be characterized by the spacing of its elements and the height of the centre element above the ground plane; radio receiver means to obtain from each antenna of each triplet an information signal of which both amplitude and phase relative to the amplitude and phase of information signals obtained from other antennae of each triplet are functions of the elevation angles θ of incidence upon the array of a radio wave arriving from a remote source and of the ground reflection coefficient p; first logic means (56 in FIG. 5) associated with each triplet to combine vectorially the information signals obtained from the outermost antennae of that triplet to provide a first derived signal of which the amplitude represents the modulus of such combination; second logic means (58 in FIG. 5) associated with each triplet arranged to derive from an information signal obtained from the centre antenna of each triplet a second derived signal of which the amplitude represents the modulus of that information signal from the said centre antenna; dividing means associated with each triplet arranged to divide one derived signal by the other to provide a quotient signal for each triplet which is a function of θ but not of p; and selection means (60 in FIG. 5) to provide at least one quotient signal which provides a measure of the elevation angle. The array may either operate in a receive mode, in which case unambiguous angle measurement is provided by the signal processing circuits embodied in the antennae receivers, as described, or in a transmit mode in which case the transmitted signal from each antenna in the array must be coded so that it can be identified to enable a quotient representing angle to be derived for each triplet in a remote receiver. It will be noted that a common coherent carrier is required for the transmissions from each element of any triplet to achieve the interferometric performance, but that coherence between triplets is not required. BREIF DESCRIPTION OF THE DRAWINGS The invention will now be described by way of example only with reference to the accompanying drawings, in which; FIG. 1 illustrates the prior art arrangement using a single triplet. FIG. 2 illustrates the principle of operation of an antenna array arranged as triplets. FIG. 3 illustrated a practical embodiment of an antenna arranged as three triplets. FIG. 4 is a plot of signal against elevation for the three triplets illustrated in FIG. 3. FIG. 5 illustrates a possible circuit for measuring the quotient signal. FIG. 6 illustrates the possible use of the array shown in FIG. 3 for determining the range, identity and elevation angle of an aircraft carrying a suitable transponder. DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS In FIG. 2, three triplets of a general set are shown, each having three antennae A, B and C spaced in line at right angles to, and above a ground plane, shown shaded. The three triplets are respectively referenced a, b and q, and have different spacings d, and different heights h above the ground plane of the central antenna B in each triplet. Only three triplets are shown, but in principle two or more can be provided. In each triplet, the two output signals (B) and (A+C) are indicated. The triplet arrays may be used in receiving or transmitting mode, and one application of each will be described by way of example. FIG. 3 shows seven antenna elements deployed as three triplets arranged to operate on responses from secondary surveillance radar interrogations, at a wavelength of about 30 centimeters. It is assumed, for this example, that processing the signals to determine the quotient is best carried out on the signals A+C and B after detection by "square law" detectors. The design aims in this example, are; to provide unambiguous angle measurements up to about 7 degrees. to provide measurement accuracy and resolution of the order +/-0.05 degrees from 3 degrees, at which aircraft normally approach to land, down to the lowest angle possible (about +0.5 degrees in this case). use the smallest number of antenna elements possible, with the lowest element not so close to the ground, that it might be obscured, and the highest antenna element at an acceptable height. d is chosen for the elevation angle, at which most measurement sensitivity is required, and h is chosen for the elevation angle at which S is close to its maximum value. For these criteria values for h and d are calculated from the relationships; 2·II·d·sinθ/λ=(n+1)II/4. . . (4) 2·II·h·sinθ/λ=(n+1)II /2. . . (5) where n is the integer 0,1,2,3,. . . In this example values of d and h are optimized for approximately the same elevation angles, so that amplitude S is at a maximum and altering slowly at angles where sensitive measurements are needed. It will also be noted that in this example, three triplets are sufficient to give the unambiguous sector coverage required (approximately 0.5 degrees to 7.0 degrees), and that by examining and averaging the three measurements obtained a judgement on optimum measurement integrity can be made. Referring to FIG. 3, the triplet (n) is arranged to give its best measurements at around one degree and three degrees, the triplet (m), to give its best measurements at around two degrees and the triplet (l), its best at around five degrees. All readings are examined at each elevation angle to decide which triplet measurement is to be preferred, and the extent of the agreement between the three readings is a measure of the integrity of the system. In general, a suitably weighted average of the three readings will give the optimum result. Typical values that might be chosen for d and h, in wavelengths, are then as follows; ______________________________________(d) (l) = 1.5 h (l) = 2.5(d) (m) = 3.75 h (m) = 7.75d (n) = 7.5 h (n) = 15.25______________________________________ The highest element is at 22.75 wavelengths, which is about 7 metetrs from the ground. It will be noted that, subject to a small variation to allow antenna elements to be shared between triplets, h=2d, and that common values of sin θ satisfy both equations (4) and (5) for all values of n. Thus, a very long array with a suitable ambiguity resolving system, is capable of giving very high angle measurement accuracy over each of its high amplitude regions. The thick lines on FIG. 4 show the preferred measurement ranges for each triplet l, m and n. This example is appropriate to the important application of monitoring the height of aircraft approaching to land, which, hitherto, has not been easily achieved with the standard secondary surveillance radar system. However, many other arrangements are possible for civil and military applications, where the measurement of the elevation angle of an emitting or reflecting object is required. FIG. 5 shows one of many possible arrangements for measuring the quotient {(A+C)/B}, all squared. Superheterodyne receivers (e.g. superheterodyne frequency converters 50 and 52 fed by a common local oscillator. will normally be necessary to achieve the sensitivity required and the dynamic range of function (S), for example, for an aircraft flying from a range of 20,000 metres to one of 200 metres will be large. However, 2B>(A+C) and the squared quotient is always positive and, normally, will be in the range 0.33 to 0.67. In FIG. 5, a divider 54 is used, where B sets the gain of two balanced amplifiers (A1 and A2), and a timer (T) and comparator (C) measure the decay time of the CR circuit from a charged voltage corresponding to 4{B squared} from second circuit 58, to the voltage corresponding to {(A+C) squared} from first circuit 56. It is well known that the exponential nature of the decay, ensures that the time delay measured at the output of divider 54, is a function of the quotient required, and is independent of the absolute amplitude of the signals. In a further refinement the received signals are sampled as quickly as possible after their arrival, so that multi-path interference effects from lateral, and therefore delayed, reflections are minimized. The particular desired one of the triplets 1, m, n may be selected by selector 60 for further processing. However, other suitable circuits may be used. FIG. 6 shows a system in which a directional secondary surveillance radar interrogator (I), measures the range of identified aircraft (T), and triggers a measurement, by the elevation measuring system (E) described, on part or all of the reply message from the selected aircraft. Thus angles are firmly associated with particular identified aircraft, at a known range. In one possible embodiment, the high directivity of the interrogator antenna (A) is also used to set the seven degree upper coverage limit, by blanking the system, when the signals it receives, fall below those received by any antenna in the elevation array. An alternative application of the antenna array shown in FIG. 3, is to provide coding, by radio transmissions, of angles in space. Triplet l may be energized by a coherent carrier in which elements A and C are amplitude modulated at a frequency l(a) and B at a frequency l(b). The modulation sidebands will carry the effective amplitude of the carrier, and the quotient of the amplitude of l(a) divided by the amplitude of l(b) may be derived, after demodulation, in a remote receiver. Likewise quotients m(a) divided by m(b) and n(a) divided by n(b) may be derived, and the optimum value of the elevation angle of the receiver with respect to the array ground plane, obtained.

An antenna array for radio interferometry uses three equi-spaced triplets set vertically above the ground with different respective spacings, the center antenna of each triplet being at a different height. Signal processing circuits provide for each triplet a signal which is a function of the elevation angle θ but is independent of the ground reflection coefficient, P. the signals are weighted to give the optimum value of θ, e.g., by selecting the signal varying most rapidly with θ. Some antennae can be shared and for example three triplets may be provided by seven antenna elements.

big_patent

FIELD OF THE INVENTION [0001] The present invention relates to the field of high intensity, thermal, efficient incandescent lamps, subminiature lamps, lamp assemblies, and a lamp system and method of making an efficient high intensity bulb and sleeve system having a liquid tight seal. BACKGROUND OF THE INVENTION [0002] Small incandescent lamps, especially subminiature lamps, have a glass envelope which has traditionally been supported by a one or two piece base. The base typically has a low pitch thread for providing mechanical fixation to a socket, as well as for providing a conductor for one conductor of a two conductor subminiature lamp element. In most subminiature lamps of this type conduction for the other conductor is provided through a peg conductor centered in an insulator carried at the bottom-most part of the lower base. [0003] The upper glass envelope has to be supported. Normally a metal sleeve is employed which fixes movement of the conducting leads, aligns the envelope with respect to the sleeve, and permanently supports the glass envelope throughout its life. Current practices for holding a subminiature lamp in a metal housing employs a ceramic adhesive between the glass envelope and the inside of a metal support sleeve. [0004] The use of an adhesive to support the glass envelope within a metal sleeve has a number of problems. First, this adhesive eventually breaks down from repetitive use of the subminiature lamp due to the thermal cycling between the high temperature of the lamp's operating temperature and its return to room temperature. The subminiature lamp temperature can be as high as 300° C. [0005] Secondly, the use of any material to bond a glass envelope having a low thermal expansion characteristic to what is typically a metal sleeve having a much higher thermal expansion coefficient will cause a destructive shear each time the subminiature lamp is thermally cycled. This shearing movement, combined with other factors hastens the degradation of the adhesive material used within a subminiature lamp. [0006] Third, and particularly where the subminiature lamp is exposed to an environment where it needs to be cleaned or sterilized, such as a contaminated medical environment, liquid cleaning procedures can degrade the adhesive. Where the subminiature lamp is used for examinations or operations, a high cyclical rate of cleaning occurs over the life of the subminiature lamp. [0007] Fourth, moisture migrates through the fracture cracks of the adhesive into the interior of the subminiature lamp. The moisture causes the electrical contacts to corrode which causes early subminiature lamp failures. The combination of the above four factors works together to cause conventional subminiature lamps to fail at an unacceptably high rate. [0008] One configuration proposed to combat the aforementioned problems includes the use an internal 0 -ring in place of the adhesive to try to prevent liquid from migrating into the subminiature lamp internals, but this has proven unworkable as the manufacture and placement of a thin o-ring is extremely difficult and problematic. A housing external 0-ring can provide a seal between subminiature lamp metal housing and the socket, but only helps prevent liquid from entering the subminiature lamp interior from the socket end. [0009] Another problem with conventional subminiature lamps is the high amount of heat which is conducted from the glass envelope. Much of the heat immediately makes its way into the metal housing. In appliances where the subminiature lamp is mounted near the outside of the appliance, burns can result from touching the metal sleeve. Even where a heat insulatory sleeve is mounted peripherally outwardly of the metal base or metal housing, burns can still occur if the end of the housing is inadvertently touched. [0010] What is needed is a solution which will provide a much longer bulb life by combating the above mechanisms of bulb degradation. The solution should also help provide further protection from burns for users, regardless of the type of appliance in which the bulb is used. SUMMARY OF THE INVENTION [0011] The subminiature lamp assembly of the present invention utilizes a high temperature polymer which directly surrounds and is in compression contact with the glass envelope. The polymer may preferably derive support from a metal base. The polymeric material is somewhat rigid/molded and can be manually handled and used to manipulate the subminiature lamp. A fluoroelastomer is a preferable type of elastomer which has the chemically resistive properties and ability to withstand high temperature which can be advantageously employed. The elastomer used for the seal supported lamp assembly provides (1) extended axial length sealing, (2) heat resistance, (3) ease of handling, and (4) increased resistance to invasion and chemical attack. BRIEF DESCRIPTION OF THE DRAWINGS [0012] These and other aspects of the invention will be better understood from the following description in which reference is made to several drawings of which: [0013] FIG. 1 is a side cross sectional view of a prior art incandescent subminiature lamp and base with an optional peripheral thermal insulative coating, axially compressed “o” ring, and shown in a subminiature lamp socket; [0014] FIG. 2 is a side cross sectional view of a prior art incandescent subminiature lamp and base with an optional peripheral thermal insulative coating, and a radially compressed “o” ring, and shown in a subminiature lamp socket; [0015] FIG. 3 is a side cross sectional view of a first embodiment of the invention with the polymeric supporting cover fitted over the subminiature lamp glass envelope and over at least a portion of the subminiature lamp base; [0016] FIG. 4 is a configuration in the same general orientation as seen in FIG. 3 but with a potting material such as pourable silicone directly under the glass envelope and helping to stabilize the electrical leads; and [0017] FIG. 5 is a side cross sectional view showing the subminiature lamp of FIG. 4 mounted in a socket having a dimension such that a lower directed radial face of the molded sleeve opposes an upper directed radial face of the socket. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0018] The prior art will first be illustrated to show the subminiature lamp environment conventionally in use. Referring to FIG. 1 , a conventional subminiature lamp assembly 21 is seen. An optical envelope assembly is seen as having an outer glass envelope 23 which may have an optional thickened lens portion 25 near a filament 27 to either focus or disperse the light leaving the filament. A pair of electrical leads extend down, both below and out of the boundary of the glass envelope 23 and through what is shown as a one piece conductive base 35 . Lead 31 is pressed against the inner surface of the base 35 by an insulative plug 37 . Lead 33 is typically pressed against the outer surface of a conductive plug 39 by the inside of the insulative plug 37 . A first type of conventional socket 41 includes a conductive outer portion 43 which includes an inner threaded portion 45 . Socket 41 has a center conductor 47 . Socket 41 may also have an upper radial surface 49 opposed to a polymeric supporting cover 22 which covers the one piece conductive base 35 completely. In this case, the polymeric supporting cover 22 is simply applied to a continuous metal surface. Lateral heat flow is slowed, but the open end of the one piece conductive base 35 remains exposed and can burn users even more readily than inadvertent contact with the outer glass envelope 23 . [0019] A thin layer of cement or adhesive 51 is used predominantly to fix the axial position of the envelope 23 within the upper portion of the one piece conductive base 35 . The tolerance between the envelope 23 and the inner cylindrical wall of the upper portion one piece conductive base 35 is small enough to promote control of the thin layer of cement or adhesive 51 . Repeated washing and sterilization begin to degrade and erode the thin layer of cement or adhesive 51 from the front end of the conventional subminiature lamp assembly 21 , where contaminants are then able to reach the leads 31 and 33 . [0020] The other path for entry, from the outside between the socket 41 and engaged one piece conductive base 35 , is guarded by an “o” ring 55 . It should be kept in mind that path guarded by the “o” ring 55 is more tortuous and less likely to “infect” the conventional subminiature lamp assembly 21 , because any contaminants must continue downward, not be lost in the area between the center conductor 47 and conductive outer portion 43 , and then navigate the very tight spaces between the inside of the one piece conductive base 35 , the insulative plug 37 , and the conductive plug 39 . As such, the “o” ring 55 is largely to protect the inside of the socket 41 . In addition, the “o” ring 55 is shown in a configuration to be compressed axially. [0021] Referring to FIG. 2 , a view of the prior art conventional subminiature lamp assembly 21 as seen in FIG. 1 is shown, but with a socket 53 which accommodates an “o” ring 55 for lateral compression. One piece conductive base 35 carries a stop structure 57 engaged by a complementary structure of the socket 53 . In this configuration, the “o” ring 55 is radially compressed by the side wall of the one piece conductive base 35 against the inside of the socket 41 . [0022] Referring to FIG. 3 , an isolated view of a seal supported subminiature lamp assembly 71 is seen outside of the socket 41 environment. A polymeric seal support 73 is seen as having a bore 75 which tightly forms a seal around the glass envelope 23 . The polymeric seal support 73 also extends downward into contact with the upward face 77 of an abbreviated height one piece conductive base 79 . The polymeric seal support 73 also extends downward and over the exterior of the abbreviated height one piece conductive base 79 . The length to which the abbreviated height one piece conductive base 79 extends may depend on the support needs of the glass envelope 23 and may also depend upon the height to which a socket 41 rises about the abbreviated height one piece conductive base 79 . In some cases, as will be shown, an axially bottom face 81 can be used to seal against a matching face on a socket 41 if one exists. [0023] The material used for the polymeric seal support 73 should be non thermally conducting and able to withstand significant subminiature lamp temperature. One material which has been shown to work well is a material sold under the trademark VITON® and is a fluoroelastomer commercially available from DuPont Dow Elastomers. It is known for its excellent (400° F./200° C.) heat resistance, as well as offering excellent resistance to aggressive fuels and chemicals. It is available with a variety of mechanical properties. The material can be pre-selected to resist permeation and volume increase, resist attack and property degradation caused by chemicals and fluids. The range of degradation resistance includes resistance to amines or caustics, resistance to hydrocarbon fluids such as are used in sterilization, and controlled flexibility at low temperature which translates into the ability to maintain a seal at a range of temperatures from low temperature to high temperature. The seal is maintained during the subminiature lamp assembly 71 operation, is maintained during heat sterilization, and its integrity continues to remain during the introduction of low temperature sterilizing liquids. [0024] In terms of the shape of the polymeric seal support 73 seen in FIG. 3 , the material is available as a solid cylindrical rope which can be bored out to accommodate the glass envelope 23 , as well as to custom fit any type of abbreviated height one piece conductive base 79 . The part may also be a molded component. Any shape of fit between the abbreviated height one piece conductive base 79 and the polymeric seal support 73 which promotes structural cooperation, support and efective bonding is encouraged. For example, the upward face 77 can be shaped to complementarily fit a matching internal surface of the polymeric seal support by the use of any complementary matching structures, including but not limited to teeth, the provision of an extended annular space containing an annular extent of the polymeric seal support 73 between the glass envelope 23 and an extended internal surface of the abbreviated height one piece conductive base 79 . Fingers projecting upwardly from the abbreviated height one piece conductive base 79 can also be used. The fingers can be either complementary to the internal shape of the polymeric seal support 73 or may be thinner and pierce the material of the polymeric seal support 73 without disrupting the seal between the cylindrical periphery of the glass envelope 23 and the matching cylindrical inside of the polymeric seal support 73 . [0025] The construction of the seal supported subminiature lamp assembly 71 can include keyed spacing and placement of the envelope 23 and abbreviated one piece conductive base 79 into a matching space within the polymeric seal support. Any material can be used between the glass envelope and abbreviated height one piece conductive base 79 to fix them for the time and force required to fit the polymeric seal support 73 . [0026] As seen in FIG. 3 is the polymeric seal support 73 forms a housing around both the glass envelope 23 and the abbreviated height one piece conductive base 79 . The polymeric seal support 73 now encapsulates the glass envelope 23 making a liquid tight seal. Where it is preferable, the polymeric seal support 73 material may be chosen based upon the maximum working temperature of the elastomer. Fluorocarbon has a maximum temperature of 200° C. and silicone has a maximum temperature of 232° C. These materials must withstand the operating temperature of the subminiature lamp bulb or glass envelope wall, especially the point nearest the filament. This hottest point will have a temperature which may vary with different subminiature lamp wattage ratings. These types of elastomer materials are also selected because they are chemically non reactive. Further, because they are polymeric, the possibility exists to include additives where it is important to achieve other objectives. The simplest might include, color for instance, where the material additive makes quick selection of the seal supported subminiature lamp assembly 71 of paramount importance. Color can also affect the electromagnetic absorbance of the material. [0027] Another possibility is to either use a combination of materials for the polymeric seal support 73 . For example, the polymeric seal support 73 may have a much more dense material in its lower half to better support the glass envelope 23 with respect to the abbreviated height one piece conductive base 79 , and a less dense upper half of material to provide additional insulation. In this event, the lower sealing would be more important. A more complete seal, however will likely depend upon the length of axial touching of the polymeric seal support 73 against the length of the glass envelope 23 , and without a break in the material used for the polymeric seal support 73 . [0028] Referring to FIG. 4 , an added feature is shown along with dimension lines useful in illustrating the dimensions of the seal supported subminiature lamp assembly 71 . Underneath the glass envelope 23 , a volume of potting material 85 , which may be pourable or non-pourable, and may be added with appropriate spacing of the glass envelope 23 with respect to the abbreviated height one piece conductive base 79 to fix it stably. The potting material may include silicone, epoxy or any other stable, temperature resistant material. Also, the addition of such potting material 85 will also better protect the upper portions of the leads 31 and 33 . The potting material 85 should be sufficient to withstand any axial compression of the glass envelope 23 against the abbreviated height one piece conductive base 79 as the polymeric seal support 73 is being fitted. The external surface of the glass envelope 23 and the internal surface of the polymeric seal support 73 should not have the presence of any material which might promote wicking. [0029] To give one possible set of dimensions of a subminiature lamp with which the inventive method and materials may be practiced, FIG. 4 includes a set of letter designations associated with the dimension lines shown. A typical seal supported subminiature lamp assembly 71 might include a glass envelope having a diameter “A” of approximately 0.176 inches and fitted with a polymeric seal support 73 having bore 75 of approximately 0.171 inches in diameter which will stretch to fit around the glass envelope and assume an internal diameter of 0.176 as it applies force along the axial surface of glass envelope 23 . [0030] The overall exterior diameter of the polymeric seal support 73 may have a diameter “B” of approximately 0.35 inches. The overall height of the glass envelope 23 may be a dimension “C” of approximately 0.550 inches. The overall height of the polymeric seal support 73 is a dimension “D” of about 0.73 inches. The overall height of the seal supported subminiature lamp assembly 71 is a dimension “E” of about 1.085 inches. The thickness of the polymeric seal support 73 lying just outside of and covering the abbreviated height one piece conductive base 79 may have a radial thickness of about 0.37 inches. [0031] Referring to FIG. 5 , a view of the seal supported subminiature lamp assembly 71 mounted within a socket 41 illustrates the possibility that the axial bottom face 81 of the polymeric seal support 73 can meet and press against the upper radial surface 49 of the socket 41 . This mechanism can provide additional sealing and also supply additional friction to help keep the seal supported subminiature lamp assembly 71 from turning out of its threaded socket 41 . [0032] In terms of theory of operation, the polymeric seal support 73 makes a static radial seal (seal on inside of the polymeric seal support 73 ) with the straight sidewall of the subminiature lamp glass envelope 23 surface. The actual polymeric seal support 73 seal length (subminiature lamp glass envelope 23 cylindrical surface to polymeric seal support 73 ) is now much longer than conventional “o” ring type seals. [0033] Internal O-ring seals have a resulting seal length, glass to o-ring, in the vicinity of 0.027 inches, assuming an o-ring width of 0.032 inches. Polymeric seal support 73 seals are accordingly longer lengths because the elastomer now is in contact with approximately the whole straight portion of glass of the glass envelope 23 , which can be about 0.350 inches long in accord with the dimensions discussed for FIG. 4 . By calculation, 0.350/0.027 represents a ratio of thirteen times longer length seal at the desired compression level. Stretch levels and compression level are recommended by the industry to range between 1 and 5% of the resting stretch and compression to limit accelerated aging and elastomer decomposition. In this case the bulb OD is specified at 0.176 inches and the ID of the polymeric seal support 73 is specified at 0.171 inches. The stretch level thus can be computed as (0.176/0.171)−1=0.0292≈3%. [0034] The second advantage of the seal supported lamp assembly 71 over conventional lamps with adhesive or cement is the elimination of either adhesive or cement. Adhesive is usually applied to the ID of the base and a conventional subminiature lamp is inserted to a designed reference point within the base. Normally this reference point is the tip of the subminiature lamp envelope. Metal housings are machined to allow a clearance of about 0.003 inches with respect to the glass portion of the conventional subminiature lamp to allow for the volume of the adhesive. As a result, the application of the adhesive is normally uneven around the internal diameter of the metal housing. That is, one side may get more adhesive than the other requiring more distance/volume between subminiature lamp and metal housing on one side. [0035] This creates an off center condition for the conventional subminiature lamp to the central axis of the base. The polymeric seal support 73 has the inherit quality to allow much closer tolerance centering of the subminiature lamp glass envelope 23 to the axis of the abbreviated height one piece conductive base 79 because there is no adhesive. The stretch ratio given, and its close equivalents are sufficient to hold the subminiature lamp in place. [0036] Further, the leads 31 and 33 as shown have an interference fit, at the abbreviated height one piece conductive base 79 and the insulative plug 37 , as well as between the insulative plug 37 and the conductive plug 39 . These interference fits create tiny open passageways around each side of the leads 31 and 33 . Therefore the internal seal supported subminiature lamp assembly 71 internal space below the glass envelope 23 has a gas composition is equal and shared by the instrument internal gas volume (best represented by the space between the center conductor 47 and conductive outer portion 43 seen in FIG. 5 ). Assembly of the subminiature lamps generally to an instrument consists of inserting the threaded end of the subminiature lamp into the instrument orifice and turning the subminiature lamp. The threads engage and draw the subminiature lamp into the instrument until the subminiature lamp base hits either a fixed stop 57 , or conversely the “o” ring 55 is available to be compressed. The human hand exerts torque to compress this type of “o” ring seal 55 . A seal is made on two sides of the “o” ring seal 55 , top and bottom, and is called a static facial or axial seal. Tolerance problems involving three connected parts result in poor seals. [0037] An example of a conventional poor stretch seal of a conventional “o” ring seal around an outer diameter part at 0.208 with an inner diameter “o” ring seal at 0.207 gives (0.208/0.207)−1=0.0048≈0.48% resulting in a poor seal. The compression seal associated with an “o” ring OD at 0.288″ and the instrument “compressed bead” internal diameter at 0.270″ calculates to be (0.288/0.270)−1=7%. A severe imbalance with the seal length much diminished from what was required. The weakest link here would be a 0.48% stretch level “o” ring to a base outer diameter creating a poor stretch seal. [0038] Conventional “o” ring seals traditionally require 2 points to make a seal. The stretch seal around a conventional subminiature lamp housing and the compression seal with the instrument can create a stretch level and compression level which should be in the 1-5% range. [0039] Thus, the next advantage of using a polymeric seal support 73 seal is that again only one surface is required to make a seal. The bottom surface of the molded polymeric seal support 73 is actually a sealing surface, axially bottom face 81 in facial contact with upper radial surface 49 . Compression values are directly related to turning forces used to insert the subminiature lamp into the instrument. This area's operating temperature is 75% less in operating temperature than the area near the filament 27 . Thus degradation of the material of the seal between the axially bottom face 81 and upper radial surface 49 is significantly reduced with increased excessive compression forces. No “o” ring 55 is required inside the instrument, but it may be used. Dead spaces or passageways that lead to the “o” ring are eliminated from collecting debris. [0040] The current objective is to fabricate a lamp, and in particular a medical subminiature lamp as a seal supported lamp assembly 71 assembly having a liquid tight seal. The above descriptions detail many forms of seals, which possibly would inhibit liquid from entering the interior of the seal supported subminiature lamp assembly 71 and its instrument as represented by the socket 41 . Entry of deleterious fluide can corrode contact points, lead 31 connection to metal housing 35 , lead 33 to plug 39 , plug 39 to contact 47 , and metal housing 35 to socket thread 45 . [0041] The above physical structures represent the potential for an early failure mechanism. As described, they are static conditions. In actuality, a subminiature lamp is cycled on and off. Air, internal to any subminiature lamp and instrument, is trapped and is building in pressure during the length of an examination when the lamp is lit. Since the internal volume of subminiature lamp/instrument is constant, under conditions of heating the increasing pressure releases itself through the shortest seal length/compression level. This escape of air can occur at the subminiature lamp end or the instrument end. Conversely, when the subminiature lamp is depowered and cools down, ambient atmospheric pressure reverses the flow forcing air through the lowest seal compression level/seal length into the subminiature lamp/instrument cavity. This air can be significantly laden with water vapor, chemicals, and human excretions that are potentially harmful to conventional elastomers and leads 31 and 33 and contact points. Conventional elastomers used tend not to be compatible with steam at temperatures around 177° C. Any internal volumes including those in the lamp housing and instrument, that have “inhaled” water vapor on preceeding light ups and will start expiring water vapor through o-ring seals at the hot end of the of any lamp assembly. The hot end may exceed 177° C., and thus elastomer degradation may be increased. The goal is to minimize the number of sealing points and maximize the length of a seal surface. [0042] Another objective is seen in FIG. 4 , where air volume is minimized by backfilling the cavity within the abbreviated height one piece conductive base 79 a pourable potting material 85 , preferably silicone. This potting material 85 would solidify and form a barrier for gasses to penetrate into the hot subminiature lamp end. [0043] In terms of assembly, a polymeric seal support 73 with close tolerances is used. An abbreviated height one piece conductive base 79 , which may preferably have a hub outer diameter (at the point where it lies underneath the polymeric seal support 73 ) of about 0.005 inches larger than the mating section of the internal bore of the polymeric seal support 73 , may be partially coated with an instant adhesive capable of bonding elastomers to metal. This area is separated significantly from the high temperature portion of the glass envelope 23 adjacent the filament 27 . [0044] During assembly, the abbreviated height one piece conductive base 79 may be inserted into the bottom end of the polymeric seal support 73 with the subminiature lamp wires exiting the internal diameter of the abbreviated height one piece conductive base 79 through the opening which would accept the insulative plug 37 . A potting material 85 may be injected into the space within the abbreviated height one piece conductive base 79 through it lower opening, or into the opening in the insulative plug 37 if lead 31 is secured first. The remaining wire is pressed against the center opening of the insulative plug 37 by insertion of the conductive plug 39 . This last procedure yields the second electrical connection. [0045] The focus of the aforementioned description has been on medical subminiature lamps, but the procedures, structures, materials and techniques can be applied to any situation where insulation, high heat degradation resistance, solvent and chemical resistance is to be derived along with positive effective sealing. [0046] Although the invention has been derived with reference to particular illustrative embodiments thereof, many changes and modifications of the invention may become apparent to those skilled in the art without departing from the spirit and scope of the invention. Therefore, included within the patent warranted hereon are all such changes and modifications as may reasonably and properly be included within the scope of this contribution to the art.

A subminiature lamp assembly utilizes a high temperature polymer which directly surrounds and is cemented to the glass envelope. The polymer may preferably derive support from a metal base. The polymeric material is somewhat rigid and can be manually handled and used to manipulate the subminiature lamp as a handle to facilitate bulb changout. A fluoroelastomer is a preferable type of elastomer which has the chemically resistive properties and ability to withstand high temperature which can be advantageously employed. The elastomer used for the seal supported lamp assembly provides (1) extended axial length sealing, (2) heat resistance, (3) ease of handling, (4) increased resistance to invasion and chemical attack (5) eliminates contact corrosion, and (6) reduces lamp failure modes.

big_patent

This application is a continuation of Ser. No. 13/447,415, filed Apr. 16, 2012, which is a continuation of Ser. No. 12/401,711, now U.S. Pat. No. 8,175,189 filed Mar. 11, 2009, the entire disclosures of which are incorporated herein by reference. FIELD OF THE INVENTION The present invention relates to multiple-input multiple-output (MIMO) communications systems. More specifically, the present invention relates to precoder configuration in MIMO systems. BACKGROUND OF THE INVENTION It is well known that a Generalized Decision Feedback Equalizer (GDFE) based precoder provides the optimal capacity solution for Multi-user Multiple-Input Multiple-Output (MU-MIMO) wireless systems. However, the computational cost of determining various filters associated with the GDFE Precoder is often prohibitive and is not suitable for many practical systems. There are several known Precoding techniques which can enable a Base Station (BS) equipped with multiple antennas to send simultaneous data streams to multiple user terminals (UTs) in order to optimize system capacity. In general, Precoding for a MU-MIMO system aims to optimize a certain criterion such as system capacity or bit error rate. Selected references are noted below, together with a description of relevant aspects of the techniques proposed therein. Q. H Spencer, A. L. Swindlehurst, and M. Haardt, “Zero-forcing methods for downlink spatial multiplexing in multi-user MIMO channels”, IEEE Transactions on Signal Processing, pp. 461-471, February 2004 [1] describes a linear precoding technique, known as Block Diagonalization (BD), which separates out the data streams to different UTs by ensuring that interference spans the Null Space of the victim UT's channel. The BD technique diagonalizes the effective channel matrix so as to create multiple isolated MIMO sub-channels between the BS and the UTs. Although this scheme is simple to implement, it limits system capacity somewhat. C. Windpassinger, R. F. H Fischer, T. Vencel, and J. B Huber, “Precoding in multi-antenna and multi-user communications”, IEEE Transactions on Wireless Communications, pp. 1305-1316, July 2004[2] describes a non-linear precoding scheme known as Tomlinson-Harashima Precoding (THP). This scheme relies on successive interference pre-cancellation at the BS. A modulo operation is used to ensure that transmit power is not exceeded. Different from BD, THP triangularizes the effective channel matrix and provides somewhat higher system capacity when compared to BD. In W. Yu, “Competition and Cooperation in Multi-User Communication Environments”, PhD Dissertation, Stanford University, February 2002[3] and W. Yu and J. Cioffi, “Sum capacity of Gaussian vector broadcast channels”, IEEE Transactions on Information Theory, pp. 1875-1892, September 2004 [4], Wei Yu introduced the GDFE Precoder and showed that it achieves a high degree of system capacity. The basic components of this scheme are illustrated in FIG. 1 . The GDFE Precoder includes an interference pre-cancellation block 101 . Similar to the THP precoding scheme discussed in reference [2] above, the interference pre-cancellation helps to ensure that the symbol vector encoded at the k th step will suffer from the interference from (k−1) symbol vectors only. Information symbols u are processed by the interference pre-cancellation block 101 to produce filtered vector symbols x. The filtered vector symbols x are then passed through a transmit filter 103 denoted by matrix B to produce transmitted signals y. In reference [3] and [4], a technique based on the covariance matrix (S zz ) corresponding to “Least Favorable Noise” is proposed to compute the GDFE Precoder components. Although, this technique achieves a high degree of system capacity, the computational cost of determining the GDFE Precoder components is effectively prohibitive for a real-time implementation required by most practical systems. X. Shao, J. Yuan and P. Rapajic, “Precoder design for MIMO broadcast channels”, IEEE International Conference on Communications (ICC), pp. 788-794, May 2005 [5] proposes a different precoding technique which achieves a capacity close to the theoretical maximum system capacity. The proposed method is computationally less complex compared to the GDFE Precoder technique. However, the proposed method allocates equal power to all data streams, which may not be an effective technique for practical systems using a finite number of quantized bit-rates. Also, the proposed technique is limited to invertible channel matrices, which may not always be the case. N. Jindal, W. Rhee, S. Vishwanath, S. A. Jafar, and A. Goldsmith, “Sum Power Iterative Water-filling for Multi-Antenna Gaussian Broadcast Channels”, IEEE Transactions on Information Theory, pp. 1570-1580, April 2005 [6] derives a very useful result referred to as the MAC/BC (multiple access channel/broadcast channel) duality; and Wei Yu, DIMACS Series in Discrete Mathematics and Theoretical Computer Science, Vol. 66, “Advances in Network Information Theory,” pp. 159-147 [7] develops the concept of least favorable noise. SUMMARY OF THE INVENTION A technique is used to realize a GDFE Precoder for multi-user (MU) MIMO systems, which significantly reduces the computational cost while resulting in no capacity loss. The technique is suitable for improving the performance of various MU-MIMO wireless systems including presently planned future “4G” cellular networks. The described implementation of a GDFE Precoder relaxes the requirement for knowledge of the covariance matrix (S zz ) corresponding to “Least Favorable Noise.” This is the key component in conventional design of a GDFE Precoder and requires extensive computational cost. It also provides a uniform framework for realizing a GDFE Precoder. Unlike conventional GDFE Precoder design, the proposed method does not require channel reduction when the Input Covariance Matrix (S xx ) for downlink channel is rank deficient. The described implementation of a GDFE Precoder achieves significant improvement in computational cost over conventional GDFE Precoders. An aspect of the present invention is directed to a method for configuring a generalized decision feedback equalizer (GDFE) based precoder in a base station of a multi-user multiple-input multiple-output (MU-MIMO) wireless system having k user terminals (UTs), each user terminal (UT) having associated therewith a feedforward filter. The method comprises computing a filter matrix C using one of a plurality of alternative formulas of the invention as described below; and, based on the computation of the filter matrix C, computing a transmit filter matrix B for a transmit filter used to process a symbol vector obtained after a decision feedback equalizing stage of the GDFE precoder, computing the feedforward filter matrix F, and computing the interference pre-cancellation matrix G. Another aspect of the invention is directed to a GDFE based precoder in a base station of a MU-MIMO wireless system having k user terminals, each user terminal having associated therewith a feedforward filter. The GDFE precoder comprises a feedforward path; a feedback path; and an interference pre-cancellation block denoted by I-G disposed in the feedback path, I being an identity matrix, G being an interference pre-cancellation matrix. A feedforward filter matrix F is related to the interference pre-cancellation matrix by a novel expression as described below. Yet another aspect of the invention is directed to a GDFE based precoder in a base station of a MU-MIMO wireless system having k user terminals, each user terminal having associated therewith a feedforward filter. The GDFE precoder comprises a feedforward path; a feedback path; and an interference pre-cancellation block denoted by I-G disposed in the feedback path, I being an identity matrix, G being an interference pre-cancellation matrix. The interference pre-cancellation matrix G in the interference pre-cancellation block is determined by computing a filter matrix C using one of a plurality of alternative formulas of the invention as described below; and, based on the computation of the filter matrix C, computing a transmit filter matrix B for a transmit filter used to process a symbol vector obtained after a decision feedback equalizing stage of the GDFE precoder, computing the feedforward filter matrix F, and computing the interference pre-cancellation matrix G. Additional features and benefits of the present invention will become apparent from the detailed description, figures and claims set forth below. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be understood more fully from the detailed description given below and from the accompanying drawings of various embodiments of the invention, which, however, should not be taken to limit the invention to the specific embodiments, but are for explanation and understanding only. FIG. 1 is a block diagram of a known GDFE Precoder; FIG. 2 is a block of a communications system using GDFE Precoding; FIG. 3 is a block diagram of configuring feedforward filter of GDFE Precoder; FIG. 4 is a flowchart of configuring a GDFE Precoder; DETAILED DESCRIPTION In the following, the system model and relevant prior art are first described in sub-section A, followed in sub-section B by a description of implementations of a GDFE Precoder. Those of ordinary skill in the art will realize that the following detailed description of the present invention is illustrative only and is not intended to be in any way limiting. Other embodiments of the present invention will readily suggest themselves to such skilled persons having the benefit of this disclosure. It will be apparent to one skilled in the art that these specific details may not be required to practice to present invention. In other instances, well-known circuits and devices are shown in block diagram form to avoid obscuring the present invention. In the following description of the embodiments, substantially the same parts are denoted by the same reference numerals. First, the system model and notations used thereafter are set forth. Let the base station (BS) have N antennas and let there be K user terminals (UTs) with L k antennas each. The sum of antennas at UTs is denoted as L=Σ k=1 K L k . Let H k denote the channel gain matrix of dimensions {L k ×N} between the BS and the k th UT. The combined channel gain matrix between the BS and the K UTs is of dimension {L×N} and is given by H=[H 1 T H 2 T . . . H K T ] T , where the superscript T denotes the matrix transpose. Let u k denote the input symbol vector destined for the k th UT, so that the stacked input vector can be represented as u=[u 1 T u 2 T . . . u K T ] T . The length of u is assumed not to exceed the number of antennas at the BS. Also, assume the additional constraint that S uu =E[uu H ]=I, where E[.] indicates the time average of its argument, the superscript H denotes the conjugate transpose and I denotes the identity matrix. A.1 DEFINITIONS Referring to FIG. 2 , a functional block diagram is shown of a MU-MIMO system having a base station 210 and user terminals 220 1 - 220 k . Each user terminal has associated therewith a feedforward filter F 1 -F k . Communications occur through a channel 231 represented by a channel matrix H. The base station includes a GDFE Precoder including a feedforward path and a feedback path. In the feedforward path, a modulo unit 233 produces a stream of filtered vector symbols X, which are filtered by a transmit filter 235 to produce a transmitted signal stream y. In the feedback path, the symbols X are fed back through an interference pre-cancellation block 237 , represented by an interference pre-cancellation matrix G subtracted from the identity matrix I. A stream of user symbols u has subtracted therefrom an output signal of the interference pre-cancellation block 237 , with the result being applied to the modulo unit 233 . Other aspects/parameters related to this system model are described below: 1). Interference Pre-Cancellation Matrix (G): This matrix is used at the transmitter at Interference Pre-cancellation Stage of the GDFE Precoder as shown in FIG. 2 . The main purpose of this matrix is to process input symbol vector u for interference pre-cancellation purposes. Its structure is that of an Upper Right Triangular matrix with block diagonal sub-matrices being identity matrices each of size a k . 2). Input Covariance Matrix for Downlink Channel (S xx ): It is defined as S xx =E[xx H ] and satisfies the transmit power constraint, i.e., trace(S xx )≦P t , where P t denotes the total available transmit power and trace(.) indicates the sum of diagonal elements of the matrix argument. The input covariance matrix for the downlink channel represents dependencies of symbols transmitted from different ones of said N transmit antennas; a sum of diagonal matrix elements represents an intended total transmit power from the N transmit antennas. In the following text, S xx will be represented using its Eigen Value Decomposition (EVD) as: S xx =VΣV H   (1) where V is a unitary matrix and Σ is a diagonal matrix with non-negative entries. 3). Transmit Filter (B): This matrix is used to process the symbol vector x obtained after the DFE stage of GDFE Precoder as shown in FIG. 2 . It is denoted by the following equation: B=VΣ 1/2 M   (2) where M is a unitary matrix and the matrices {V,Σ} are same as defined in (1). 4). Least Favorable Noise Covariance Matrix (S zz ): This may be regarded as the noise covariance matrix that results in the minimum system capacity when full coordination among all UTs is assumed. This is a positive definite Hermitian Matrix whose block diagonal sub-matrices are identity matrices of size a k . This is defined in a similar fashion to that shown in Eq. (67) of reference [4]. 5). Input Covariance Matrix for Equivalent Uplink Channel (D): It is defined similar to the Equation (3.6) of reference [7] as the correlation among the symbols of the input vector for the equivalent Uplink/Medium Access Channel (MAC) with channel matrix H H . The structure of matrix D is that of a block diagonal matrix and satisfies the transmit power constraint, i.e., trace(D)≦P t , where P t denotes the total available transmit power. Each block diagonal sub-matrix of D represents the input covariance matrix for a particular UT in the Uplink channel. A capacity optimal D can be computed using the methodology presented in reference [6]. A.2 TRANSMITTER PROCESSING As shown in FIG. 2 , the GDFE Precoder includes an interference pre-cancellation block denoted by I-G, where G has the structure of a Block Upper Right Triangular matrix. Similar to the THP precoding scheme of reference [2], the triangular structure of the feedback matrix G helps to ensure that the symbol vector encoded at the k th step will suffer from the interference from (k−1) symbol vectors only. The x k th sub-vector of x=[x 1 T x 2 T . . . x K T ] T is generated using the following relationship: x k = ( u k - ∑ m = k + 1 K ⁢ G km ⁢ x m ) + α k ( 3 ) where G km denotes the sub-matrix of G required to pre-cancel interference due to the vector symbol x m from x k . These sub-vectors are generated in the reverse order, with x K being the first generated vector and x 1 being the last one. An example of the structure of the matrix G for a 3 UT scenario is shown below G = [ I G 12 G 13 0 I G 23 0 0 I ] ( 4 ) In this particular example, x 3 is generated first, followed by x 2 from which interference due to x 3 is pre-subtracted using the sub-matrix G 23 . Lastly, x 1 is generated after pre-subtraction of interference due to x 2 and x 3 . Also, each complex element of vector α k in (3) is chosen from the following set: A={ 2 √{square root over (S)} ( p 1 +jp Q )| p I ,p Q ε{±1,±3, . . . ,±( √{square root over (S)}− 1)}}, where S is the constellation size.  (5) The elements of α k are chosen such that the elements of the resulting vector x k are bounded by the square region of width 2√{square root over (S)}. This mechanism, while allowing for interference pre-cancellation, also limits the total transmit power. The vector x is then passed through a transmit filter B to yield a vector y given by the following relationship: y=Bx   (6) The vector y is transmitted by mapping its element to the respective antenna elements of the Base Station. A.3 RECEIVER PROCESSING Let the feedforward filter employed by k th UT be denoted by F k , which is a matrix of dimension {a k ×L k } where a k denotes the length of vector u k . Now, the received baseband vector corresponding to the k th UT is given by r k =F k HBx+F k n k   (7) where x is the symbol vector derived from input symbol vector u after an interference pre-cancellation step as shown in FIG. 2 . The filter B indicates the transmit filter, and noise at k th UT is denoted by n k . The stacked received basedband vector corresponding to all K UTs can be represented as r=FHBx+Fn   (8) where, F=diag(F 1 , F 2 , . . . F K ) is a block diagonal matrix representing the feedforward filter and n represents stacked noise vector. In the following, different methods are presented to compute matrices B, G and F as defined earlier. One method assumes the knowledge of S zz whereas other methods provide ways to compute GDFE matrices without any knowledge of S zz . B. COMPUTATION OF GDFE PRECODER MATRICES Unlike prior methods, in the present method the feedforward filter, F, is expressed as: F=GM H ( HVΣ 1/2 ) H [HS xx H H +S zz ] −1   (9) where the “Least Favorable Noise,” S zz , may be regarded as the noise covariance matrix that results in the minimum system capacity when there is full coordination among all UTs. S zz may be computed using the technique described in reference [4]. The matrices {V,Σ} are same as defined in (1). The input covariance matrix S xx for the downlink channel may be computed by first computing the input covariance matrix D for the equivalent Uplink/Medium Access Channel (MAC) with channel gain matrix H H . The capacity achieved by the proposed GDFE method is the same as the capacity achieved by the choice of D for the equivalent Uplink channel. A capacity optimal D can be computed using the methodology presented in reference [6]. The input covariance matrix S x for the downlink channel can then be computed using the following equation given in reference [7]: S xx = I - [ H H ⁢ DH + I ] - 1 λ ( 10 ) where for a given total transmit power P t , the scalar variable λ can be computed as: λ=trace( I−[H H DH+I] −1 )/ P t   (11) Next, referring to FIG. 4 , a filter matrix C is defined as: C =( HVΣ 1/2 ) H [HS xx H H +S zz ] −1   (12) (step 403 in FIG. 4 ). Now, the feedforward filter F can be represented as F=GM H C   (13) It can be noted that F is Block Diagonal and G is Block Upper Right Triangular with Identity matrices forming its diagonal block. Given that M is unitary matrix; pre-multiplication of M H with C must result in a Block Upper Right Triangular matrix R. Hence, M can be obtained using the QR decomposition (QRD) of C as C=MR   (14) (step 406 ). It must be noted that the QRD is performed in such a way that all non-zero columns of C which span the same vector space contribute to only one column vector in matrix M. Computation of matrices B, G and F is then performed as follows: Compute B=VΣ 1/2 M (step 407)  (15) Set F =BlockDiagonal( R )(step 408)  (16) The BlockDiagonal(.) function extracts submatrices F 1 , F 2 . . . , F K of size {a k ×L k } from the block diagonals of the matrix R as illustrated in FIG. 3 . The number of symbols, a k , allotted to the k th UT equals the rank of F k . Compute G=FR \ (step 409)  (17) where the superscript \ denotes the Moore-Penrose Generalized Inverse. B.1 Alternate Methods to Compute C In this method, the use of S zz is avoided for computing the matrix C and subsequently other dependent matrices of GDFE Precoder. The expression (12) is rewritten as: C[HS xx H H +S zz ]=( HVΣ 1/2 ) H   (18) Next, the expression H H [HS xx H H +S zz ] −1 H=λI given in reference [7] is alternatively expressed as: [ HS xx H H +S zz ]=λ −1 HH H   (19) where λ is computed using (11). Next, the expression in (19) is substituted in (18) to obtain the following equality CHH H =λ( VΣ 1/2 ) H H H   (20) Now, for a channel matrix H whose rank is greater than or equal to its number of rows, the matrix C can be uniquely determined as: C =λ( VΣ 1/2 ) H H \   (21) (step 404 in FIG. 4 ) where the superscript \ denotes the Moore-Penrose Generalized Inverse. Furthermore, omitting the scalar operation 2 in above expression does not alter the performance of GDFE Precoder. Therefore, following expression can also be used for channels whenever the rank of H is greater than or equal to the number of rows in H (step 410 in FIG. 4 ): C =( VΣ 1/2 ) H H \   (22) For the channel matrix H whose rank is less than its number of rows, the matrix C can be determined by solving the following limit: C = λ ⁡ ( V ⁢ ⁢ Σ 1 / 2 ) † ⁢ lim X → 0 ⁢ S xx ⁡ [ H ⁢ ⁢ X ] † ( 23 ) where X is an arbitrary matrix with same number of rows as H. The number of columns in X is chosen so that the rank of the resulting matrix [H X] is greater than or equal to the number of rows in H. Here, the matrix S zz denotes the input covariance matrix for the effective downlink channel matrix [H X]. The expression in (23) can be simplified using (10) along with some matrix manipulations as C =( HVE 1/2 ) \ [I −( HH H D+I ) −1 ]  (24) This expression can be further simplified using matrix inversion identities as C =√{square root over (Σ \ )}( HV ) \ HV[I−λΣ]V H H H D   (25) Here the matrix product (HV) \ HV in (25) is equal to a diagonal matrix with leading diagonal entries being 1 and the rest of trailing entries being 0. The number of diagonal entries equal to 1 is same as the rank of H. Observing that the rank of the matrix product HV is always greater than or equal to that of Sigma, it can be ensured that the number of trailing zeros in the matrix product (HV) \ HV are always less than or equal to those in Σ. Hence the above expression in (25) can be further simplified as C =[√{square root over (Σ \ )}−λ√{square root over (Σ)}]V H H H D   (26) (step 405 in FIG. 4 ). Here it should be noted that expressions (24), (25) and (26) can be used for any arbitrary channel matrix H. However when the rank of channel matrix is greater than or equal to its number of rows, expression in (21) or (22) may be used because of possible computational efficiency. B.2 NUMERICAL EXAMPLES Example-1 Using Eq. (12) to Compute C The following numerical example illustrates the computation of various matrices involved in the design of GDFE Precoder for the case when S zz is known beforehand, i.e. C is computed using equation (12). Consider a BS with 4 antennas and 2 users with 2 antennas each, so that channel matrices associated with both the users are of dimension 2×4. Let the overall channel matrix be the following: H = [ H 1 H 2 ] = [ 0.8156 1.1908 - 1.6041 - 0.8051 0.7119 - 1.2025 0.2573 0.5287 1.2902 - 0.0198 - 1.0565 0.2193 0.6686 - 0.1567 1.4151 - 0.9219 ] ( 27 ) For fixed transmit power of 20, the optimal input covariance matrix S xx for the downlink channel can be computed by first computing the optimal input covariance matrix D for the equivalent Uplink/MAC channel as described in [6] and then using the equation (10): S xx = [ 6.0504 - 0.8646 - 0.5495 - 0.9077 - 0.8646 4.0316 - 1.5417 - 2.4559 - 0.5495 - 1.5417 5.7918 - 1.3812 - 0.9077 - 2.4559 - 1.3812 4.1262 ] ( 28 ) The Eigen Value Decomposition (EVD) of S xx can be computed as: V = [ - 0.1548 0.2203 0.9335 0.2367 - 0.5546 0.3955 - 0.3485 0.6438 0.8032 0.4608 - 0.0697 0.3711 0.1528 - 0.7634 0.0468 0.6259 ] ⁢ ⁢ and ( 29 ) Σ = [ 6.6995 0 0 0 0 6.4942 0 0 0 0 6.3688 0 0 0 0 0.4375 ] ( 30 ) Also, the “Least Favorable Noise” covariance matrix S zz may be computed using the technique described in reference [4] as S zz = [ 1.0000 0 0.4726 0.0573 0 1.0000 0.5846 0.0867 0.4726 0.5846 1.0000 0 0.0573 0.0867 0 1.0000 ] ( 31 ) Following the details outlined in Method-I, the following QR Decomposition is first computed C = ⁢ ( HV ⁢ ⁢ Σ 1 / 2 ) H ⁡ [ HS xx ⁢ H H + S zz ] - 1 = ⁢ [ - 0.3746 0.6016 0.4650 - 0.5306 0.3008 - 0.5290 0.0216 - 0.7932 - 0.0990 0.3554 - 0.8802 - 0.2985 - 0.8715 - 0.4815 - 0.0924 - 0.0118 ] ︸ M ⁢ [ 0.2669 0.2024 - 0.2817 - 0.0087 0 0.2413 - 0.0786 - 0.0562 0 0 - 0.2281 - 0.0542 0 0 0 - 0.2050 ] ︸ R ( 32 ) Next, the method computes the transmit filter matrix B as B = V ⁢ ⁢ Σ 1 / 2 ⁢ M = [ - 0.0508 0.2239 - 2.2623 - 0.9378 0.5568 - 1.9145 0.0891 0.2198 - 0.6220 0.4488 1.1241 - 1.9849 - 1.1057 1.1097 - 0.0002 1.2931 ] ( 33 ) The effective feedforward filter can be computed as: F ⁡ [ F 1 0 0 F 2 ] = ⁢ BlockDiag ⁡ ( R ) = ⁢ [ 0.2669 0.2024 0 0 0 0.2413 0 0 0 0 - 0.2281 - 0.0542 0 0 0 - 0.2050 ] ( 34 ) Therefore, the two users employ the following feedforward filters for baseband signal processing as shown in Eq. (7). F 1 = [ 0.2669 0.2024 0 0.2413 ] , ⁢ F 2 = [ - 0.2281 - 0.0542 0 - 0.2050 ] ( 35 ) Also, the interference pre-cancellation matrix G can be computed as: G = FR - 1 = [ 1 0 - 1.2347 0.2841 0 1 - 0.3447 - 0.1831 0 0 1 0 0 0 0 1 ] ( 36 ) Example-2 Using Eq. (22) to Compute C The following numerical example illustrates the computation of various matrices involved in the design of GDFE Precoder when S zz is unknown. The same system as in Example-1 with transmit power fixed to 20 is assumed so that matrices H, S xx , V, and Σ are given by Equations (27)-(30) respectively. Following the details outlined in B.1, compute the matrix C and its QR Decomposition: C = ⁢ ( V ⁢ ⁢ Σ 1 / 2 ) H ⁢ H - 1 = ⁢ [ - 0.3746 0.6016 0.4650 0.5306 0.3008 - 0.5290 0.0216 0.7932 - 0.0990 0.3554 - 0.8802 0.2985 - 0.8715 - 0.4815 - 0.0924 0.0118 ] ︸ M ⁢ [ 1.8267 1.3854 - 1.9276 - 0.0599 0 1.6511 - 0.5381 - 0.3848 0 0 - 1.5611 - 0.3712 0 0 0 1.4027 ] ︸ R ( 37 ) Next, the method computes the transmit filter matrix B as B = V ⁢ ⁢ Σ 1 / 2 ⁢ M = [ - 0.0508 0.2239 - 2.2623 0.9378 0.5568 - 1.9145 0.0891 - 0.2198 - 0.6220 0.4488 1.1241 1.9849 - 1.1057 1.1097 - 0.0002 - 1.2931 ] ( 38 ) Also, the effective feedforward filter is computed as: F ⁡ [ F 1 0 0 F 2 ] = ⁢ BlockDiag ⁡ ( R ) = ⁢ [ 1.8267 1.3854 0 0 0 1.6511 0 0 0 0 - 1.5611 - 0.3712 0 0 0 1.4027 ] ( 39 ) Therefore, the two users employ the following feedforward filters for baseband signal processing as shown in Eq. (7). F 1 = [ 1.8267 1.3854 0 1.6511 ] , ⁢ F 2 = [ - 1.5611 - 0.3712 0 1.4027 ] ( 40 ) Also, the interference pre-cancellation matrix G is computed as: G = FR - 1 = [ 1 0 - 1.2347 - 0.2841 0 1 - 0.3447 0.1831 0 0 1 0 0 0 0 1 ] ( 41 ) Example-3 Using Eq. (22) to Compute C Consider the same system as in previous example but fix the transmit power to 10 instead of 20 as in pervious two examples. In this case, the matrices associated with the GDFE Precoder can be shown to be: B = [ - 0.1416 0 - 1.6054 - 0.6715 1.3873 0 0.0617 0.1574 - 0.5284 0 0.8176 - 1.4211 - 1.0834 0 - 0.0106 0.9258 ] ( 42 ) From Eq. (42), it is apparent that the 2 nd column of B is zero, implying that the second element in x 1 is assigned 0 transmit power. It is therefore suggested to transmit only 1 symbol to UT-1 and 2 symbols to UT-2, that is set u 1 =[u 11 0] T , u 2 =[u 21 u 22 ] T so that u=[u 1 T u 2 T ] T . The rest of matrices associated with the GDFE precoder can be shown to be: F 1 = [ 0.6711 - 0.5106 0 0 ] , ⁢ F 2 = [ - 1.1131 - 0.2532 0 - 1.0043 ] ⁢ ⁢ and ( 43 ) G = [ 1 0 - 0.3246 0.2913 0 1 0 0 0 0 1 0 0 0 0 1 ] ( 44 ) Example-4 Using Eq. (26) to Compute C The following numerical example illustrates the computation of various matrices involved in the design of a GDFE Precoder when channel matrix H is rectangular. Consider a BS with 4 antennas and 2 users with 3 antennas each, so that channel matrices associated with both the users are of dimension 3×4. The overall channel matrix is non-square, for example: H = [ H 1 H 2 ] = [ 0.5869 2.3093 0.4855 0.1034 - 0.2512 0.5246 - 0.0050 - 0.8076 0.4801 - 0.0118 - 0.2762 0.6804 0.6682 0.9131 1.2765 - 2.3646 - 0.0783 0.0559 1.8634 0.9901 0.8892 - 1.1071 - 0.5226 0.2189 ] ( 45 ) Now, for fixed transmit power of 20 the optimal input covariance matrix S xx for the downlink channel can be computed using the MAC/BC duality of reference [6] and is given by: S xx = [ 4.6266 0.1030 - 0.0070 - 0.1029 0.1030 5.1215 0.0841 - 0.0162 - 0.0070 0.0841 5.1006 - 0.0201 - 0.1029 - 0.0162 - 0.0201 5.1513 ] ( 46 ) The Eigen Value Decomposition (EVD) of S xx can be computed as: V = [ 0.1964 0.0910 - 0.1458 - 0.9653 0.6582 - 0.3961 - 0.6117 0.1890 0.5017 - 0.3846 0.7731 - 0.0510 - 0.5258 - 0.8288 - 0.0825 - 0.1727 ] ⁢ ⁢ and ( 47 ) Σ = [ 5.2293 0 0 0 0 5.1456 0 0 0 0 5.0375 0 0 0 0 4.5876 ] ( 48 ) The optimal input covariance matrix D for the equivalent Uplink/MAC channel can be computed using the methods described in reference [6] as, D = [ 4.6635 - 0.1505 1.3687 0 0 0 - 0.1505 0.0049 - 0.0442 0 0 0 1.3687 - 0.0442 0.4017 0 0 0 0 0 0 5.1852 - 0.0224 - 0.0781 0 0 0 - 0.0224 5.0780 - 0.0875 0 0 0 - 0.0781 - 0.0875 4.6667 ] ( 49 ) Now, matrix C can be computed using Eq. (26) as, C = ⁢ [ Σ † - λ ⁢ Σ ] ⁢ V H ⁢ H H ⁢ D = ⁢ [ - 0.3034 - 0.9436 0.0578 0.1189 0.4305 - 0.0129 0.2946 0.8531` 0.6702 - 0.2708 - 0.6827 - 0.1066 0.5229 - 0.1899 0.6662 - 0.4968 ] ︸ M ⁢ [ - 0.2051 0.0066 - 0.0602 0.0298 0.0248 - 0.1351 0 0 0 - 0.1137 - 0.0494 0.0926 0 0 0 - 0.0365 - 0.1809 - 0.2138 0 0 0 0.1017 - 0.0913 0.1882 ] ︸ R ( 50 ) Next, the method computes the transmit filter matrix B as B = V ⁢ ⁢ Σ 1 / 2 ⁢ M = [ - 1.3479 0.0548 - 1.0671 1.2915 - 1.5520 - 1.1138 1.0294 - 0.6423 0.3822 - 1.5205 - 1.4481 - 0.7386 - 0.7619 1.2794 - 0.7433 - 1.5432 ] ( 51 ) The effective feedforward filter can be computed as: F = ⁢ [ F 1 0 0 F 2 ] = ⁢ BlockDiag ⁡ ( R ) = ⁢ [ - 0.2051 0.0066 - 0.0602 0 0 0 0 0 0 - 0.1137 - 0.0494 0.0926 0 0 0 - 0.0365 - 0.1809 - 0.2138 0 0 0 0.1017 - 0.0913 0.1882 ] ( 52 ) Therefore, the two users employ the following feedforward filters for baseband signal processing as shown in Eq. (7). F 1 = [ - 0.2051 0.0066 - 0.0602 ] , ⁢ F 2 = [ - 0.1137 - 0.0494 0.0926 - 0.0365 - 0.1809 - 0.2138 0.1017 - 0.0913 0.1882 ] ( 53 ) It is apparent from Equations 52 and 53, that the first user is assigned only one symbol whereas the second user is assigned 3 symbols. That is, u 1 =[u 11 ], u 2 =[u 21 u 22 u 23 ] T so that u=[u 1 T u 2 T ] T . The interference pre-cancellation matrix G can therefore be computed as: G = FR - 1 = [ 1 0.5545 - 0.1518 0.2721 0 1 0 0 0 0 1 0 0 0 0 1 ] ( 54 ) The foregoing methods provide a way to improve the spectral efficiency of MU-MIMO systems at computational costs within reasonable bounds. The performance improvements are essentially the same as those provided by more computationally complex GDFE Precoders. Thus, the methods are well-suited to high speed digital cellular telephony, including developing standards such as IMT-Advanced, and other forms of high speed digital communication, including wired communications. The foregoing methods may be embodied in various forms and implemented as methods, processes, systems, and components such as integrated circuits. In one typical implementation, the methods are carried out in software executed by a digital signal processor. While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that, based upon the teachings herein, changes and modifications may be made without departing from this invention and its broader aspects. Therefore, the appended claims are intended to encompass within their scope all such changes and modifications as are within the true spirit and scope of this invention.

A technique is used to realize a generalized decision feedback equalizer (GDFE) Precoder for multi-user multiple-input multiple-output (MU-MIMO) systems, which significantly reduces the computational cost while resulting in no capacity loss. The technique is suitable for improving the performance of various MU-MIMO wireless systems including future 4G cellular networks. In one embodiment, a method for configuring a GDFE precoder in a base station of a MU-MIMO wireless system having k user terminals, each user terminal having associated therewith a feedforward filter. The method comprises computing a filter matrix C using one of a plurality of alternative formulas of the invention; and, based on the computation of the filter matrix C, computing a transmit filter matrix B for a transmit filter used to process a symbol vector obtained after a decision feedback equalizing stage of the GDFE precoder, a feedforward filter matrix F, and an interference pre-cancellation matrix G.

big_patent

BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to a heat-dissipating device and a housing thereof, and more particularly to an axial fan having an increased intake airflow rate without modifying the assembling conditions with other elements so as to greatly enhance the heat-dissipating performance of the fan, and a housing for the fan. 2. Description of the Related Art A typical electrical product usually includes electrical elements positioned in a closed housing in order to prevent the electrical elements from being contaminated with particles in the air. However, since the electrical element (such as a central processing unit (CPU) or circuit board) raises its temperature during operation, the element tends to be consumed and the lifetime thereof tends to be shortened if the element is continuously kept at the high-temperature condition. Thus, a fan is typically disposed in the housing to dissipate heat to the outside in order to prevent the electrical element from failing. As shown in FIG. 1 , a conventional fan 1 is mainly composed of a fan housing 11 and an impeller 12 . When the fan is operating, a motor may be used to drive the impeller 12 to rotate and to produce air streams flowing toward the electrical element in order to dissipate the heat generated from the electrical element. The fan housing includes an air inlet and an air outlet in communication with the air inlet via a central, cylindrical air passage 11 a . The air streams caused by the impeller 12 may freely flow into and out of the fan housing via the air passage. Furthermore, a plurality of tapered portions 13 , through which the air streams may smoothly flow into the air inlet side, are provided at the corners on the air inlet side of the air passage. In addition, a plurality of screw holes 14 is formed at four corners of the fan housing such that the fan may be mounted to a frame of an electrical apparatus (i.e., a computer) via the screw holes 14 . However, due to the restriction in the dimension of the rectangular fan housing of the conventional fan, the air passage at the lateral side has to be reduced. The optimized design in the shape of the blade based on the curve of the air passage is also restricted, and the space and material of the fan housing are also wasted. Besides, due to the restriction in the construction of the fan housing, air may be taken into the fan only in the axial direction. However, it only can achieve very limited improvement effect in the increased intake airflow rate by doing so. SUMMARY OF THE INVENTION An object of the invention is to provide a heat-dissipating fan and a housing thereof, wherein an sidewall of the housing extends outwards to enlarge the intake airflow area thereof without modifying the assembling conditions between the existing fan and other heat dissipation elements, and the shape of the housing at the air outlet side is kept unchanged in order to enhance the heat-dissipating efficiency of the fan. The fan may be mounted to a system or other heat dissipation elements without changing the assembling conditions with the system and the heat dissipation elements. Another object of the invention is to provide a heat-dissipating device and a housing thereof, wherein an sidewall of the housing extends outwards to enlarge its intake airflow area so that the impeller of the heat-dissipating device may increase its dimension with the outward extension of the housing. Thus, the airflow rate may be increased and the heat-dissipating efficiency may be enhanced. Still another object of the invention is to provide a heat-dissipating fan and a housing thereof, wherein the air passage formed by the sidewall of the passage of the housing reduces gradually and evenly in its cross-sectional area. Thus, the air streams produced by the rotation of blades of the impeller of the heat-dissipating device can be effectively concentrated to the center and then blow to the center portion of the heat sink having the highest temperature when the heat sink is assembled with the heat-dissipating device so as to enhance its heat-dissipating efficiency. According to the first aspect of the invention, the housing includes an outer frame having a passage for guiding air streams to flow from an opening to another opening, wherein an sidewall of the passage of one of the opening sides extends radially outwards so as to enlarge intake or discharge area for the air streams. The sidewall of the passage extends radially outwardly with respect to a central axis of the passage in a symmetrical manner. In addition, the sidewall of the passage extends radially outwardly with respect to a longitudinal axis of the passage and beyond the peripheral edge of the outer frame. Alternatively, the sidewall of the passage extends radially outwardly with respect to a longitudinal axis of the passage in a frustum-conical or a frustum-elliptically conical manner. Preferably, the sidewall of the passage is formed with an inclined portion or a beveled edge there around. According to the second aspect of the invention, the housing includes an outer frame including an air inlet, an air outlet, and a passage for guiding air streams from the air inlet to the air outlet, wherein an sidewall of the passage at the air inlet side extends radially outwardly so as to enlarge an intake area of the air streams. Preferably, the sidewall of the passage at the air inlet side extends radially outwardly with respect to a central axis of the passage in a symmetrical manner. Alternatively, the sidewall of the passage at the air inlet side extends radially outwardly with respect to a longitudinal axis of the passage and beyond the peripheral edge of the outer frame. Furthermore, the sidewall of the passage at the air inlet side extends radially outwardly with respect to a longitudinal axis of the passage in a frustum-conical or a frustum-elliptically conical manner. Preferably, the sidewall of the passage is formed with an inclined portion extending from the air inlet to the air outlet. Preferably, the radially outward extension of the sidewall of the passage at the air inlet side is partially cut off to form a notch in order to enlarge an intake area for lateral side air streams. According to the third aspect of the invention, the heat-dissipating device includes an impeller and a housing for receiving the impeller, wherein the housing includes a passage for guiding air streams to flow from an opening to another opening, an sidewall of the passage at least one of the opening sides extends radially outwards so as to enlarge an intake/discharge area for the air streams. A dimension of a blade of the impeller increases along with the radially outwardly extending direction of the sidewall of the passage. According to the fourth aspect of the invention, the heat-dissipating device includes an impeller and a housing for receiving the impeller, wherein the housing includes an air inlet, an air outlet, and a passage for guiding air streams from the air inlet to the air outlet, and an sidewall of the passage at the air inlet side extends radially outwards so as to enlarge an intake area of the air streams. According to the fifth aspect of the invention, the heat-dissipating system includes a casing, at least one electrical element mounted within the casing, and a heat-dissipating device mounted on the casing for dissipating heat generated from the at least one electrical element when it operates, wherein the heat-dissipating device includes an impeller and a housing for receiving the impeller. Further, the housing includes a passage for guiding air streams to flow from an opening of the housing to another opening, and an sidewall of the passage at one of the openings extends radially outwardly with respect to a rotational axis of the heat-dissipating device so as to enlarge an intake/discharge area for the air streams. Preferably, the heat-dissipating device is an axial fan. Further, the heat-dissipating device includes a heat sink assembled with the housing. According to the sixth aspect of the invention, the heat-dissipating system includes a casing, at least one electrical element mounted within the casing, and a heat-dissipating device mounted on the casing for dissipating heat generated from the at least one electrical element when it operates, wherein the heat-dissipating device includes an impeller and a housing for receiving the impeller. Further, the housing includes an air inlet, an air outlet, and a passage for guiding air streams to flow from the air inlet to the air outlet, wherein the sidewall of the passage at the air inlet side extends radially outwardly with respect to a rotational axis of the heat-dissipating device so as to enlarge an intake area for the air streams. Other objects, features, and advantages of the invention will become apparent from the following detailed description of the preferred but non-limiting embodiments. The following description is made with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top view showing a conventional fan. FIG. 2A is a perspective view showing a heat-dissipating device according to a first preferred embodiment of the invention. FIG. 2B is a top view showing the heat-dissipating device of FIG. 2A . FIG. 2C is a cross-sectional view showing the heat-dissipating device taken along a line A-A′ of FIG. 2B . FIG. 2D is a cross-sectional view showing the heat-dissipating device taken along a line B-B′ of FIG. 2B . FIGS. 3A and 3B are cross-sectional views showing several modified structures of the housing for the heat-dissipating device of the invention, wherein FIG. 3A also shows the direction of the flow field. FIG. 4A is a top view showing the housing for the heat-dissipating device according to another preferred embodiment of the invention. FIG. 4B is a cross-sectional view showing the heat-dissipating device taken along a line C-C′ of FIG. 4A . FIG. 5 is a top view showing a housing for the heat-dissipating device according to still another preferred embodiment of the invention. FIG. 6 is a perspective view showing the heat-dissipating device according to another preferred embodiment of the invention. FIG. 7 is a schematic illustration showing the heat-dissipating device of the invention mounted in a system frame having with electrical elements disposed therein. FIG. 8A is an exploded, cross-sectional view showing the assembly of the heat-dissipating device of the invention and the heat sink. FIG. 8B is a cross-sectional view showing the combination of the heat-dissipating device and the heat sink of FIG. 8A . FIG. 8C is a perspective view showing the combination of the heat-dissipating device and the heat sink of FIG. 8A . FIG. 9 is a schematic illustration showing the assembly of the heat-dissipating device of the invention and the heat sink, which is disposed in the framework with electrical elements. FIG. 10 is another schematic illustration showing the assembly of the heat-dissipating device of the invention and the heat sink, which is mounted on the casing. DETAILED DESCRIPTION OF THE INVENTION Referring to FIGS. 2A to 2D , which show a heat-dissipating device according to a first preferred embodiment of the invention. The heat-dissipating device 2 is mainly composed of a housing and an impeller 22 . The housing includes a rectangular outer frame 21 having an air inlet, an air outlet, and a passage 23 connecting the air inlet to the air outlet. An sidewall 23 a of the passage extends radially outwards with respect to a rotational axis of the fan motor of the heat-dissipating device or an axis of passage, or even protrudes over the rectangular outer frame 21 . Since the air inlet side of the housing has a circular shape extending outwards, the bottom part of the housing is still kept as a rectangular shape, and screw holes 24 and their positions are kept unchanged, the way of assembling the housing with other elements is also kept unchanged. The dimension of the blade of the impeller can be enlarged along with the outward extension of the sidewall of the housing, and an inclined portion 231 can be formed at the sidewall of the housing, as shown in FIG. 2C . The inclined portion 231 can greatly enlarge the intake airflow area and reduce noises of the turbulent flow produced owing to uneven intake airflow area of the conventional fan. In addition, an inclined portion 232 can also be designed at the sidewall of the air outlet side of the housing, as shown in FIG. 2D , wherein the inclined portion 232 can significantly increase the heat-dissipating area of the air outlet side. In addition to the designs of inclined portions towards different directions at the sidewall from the air inlet side to the air outlet side, the sidewall may be formed with an inwardly inclined portion from the air inlet side to the air outlet side of the housing, as shown in FIGS. 3A and 3B . In this case, the air streams can be concentrated toward the center to provide better heat-dissipating performance for the heat-dissipating device that requires concentrated air streams. In addition, the fan housing assembly housing may be formed with a beveled edge at the air inlet side around the screw holes so that the intake airflow area can also be enlarged. Furthermore, in addition to the sidewall of the passage at the air inlet side extending radially outwards and protruding over the rectangular outer frame 21 , the same designs may be configured at the air outlet side. In other words, the sidewall of the passage at the air outlet side also extends radially outwards and protrudes over the rectangular outer frame 21 , as shown in FIGS. 4A and 4B , such that the sidewalls at the air inlet side and the air outlet side have a symmetrical structure with respect to a longitudinal axis L of the air passage including the same axis or a horizontal median plane H of the heat-dissipating device. In addition that the sidewall of the passage at the air inlet side of the housing as shown in FIG. 2A evenly radially extends outwards in a circular manner, it can also be designed into an elliptic shape extending outwards in a symmetrical manner, as shown in FIG. 5 . In other words, the sidewall of the passage at the air inlet side of the housing can extend radially outwards in a symmetrical manner with respect to the longitudinal axis L of the air passage, that is, in a right-and-left or upper-and-lower symmetry from the top view of the housing. In addition to the outward extension of the sidewall of the housing, when the lateral side of the housing cannot be extended owing to the dimensional limitation, a part of the side wall of the housing may be cut off to form a notch or notches, as shown in FIG. 6 . In this case, the intake airflow area at the lateral side can be enlarged, the air can be smoothly introduced, and the noise can also be reduced. In practice, the heat-dissipating device 2 may be disposed within a system casing 3 in which electrical elements are mounted, as shown in FIG. 7 . Several heat sources or electrical elements, which will generate a lot of heat during operation, are mounted on a circuit board 4 . The heat-dissipating device 2 of the invention is mounted to a proper position (close to the heat sources) to discharge air streams toward the heat sources or electrical elements. Thus, the heat-dissipating efficiency can be enhanced, and it is possible to prevent the electrical elements from being damaged owing to high-temperature conditions. In addition, the heat-dissipating device 2 of the invention may also be used with a heat sink 31 , which may be mounted to the heat-dissipating device 2 by screws 32 , as shown in FIGS. 8A to 8C . The assembly may be mounted to a central processing unit (CPU) 5 , as shown in FIG. 9 and FIG. 10 . That is, the bottom surface of the heat sink 31 is in close contact with the surface of the CPU 5 , and the heat generated by the CPU 5 during operation may be quickly conducted to the heat sink 31 . Then, the heat-dissipating device 2 produces cooling air streams to dissipate the generated heat. Moreover, the design of the inclined portion of the sidewall of the passage of the heat-dissipating device 2 of the invention may further be utilized to guide air streams toward the central portion of the heat sink having the highest temperature, and the heat-dissipating effects may be effectively achieved accordingly. In summary, according to the aspect of the invention, the outward extension of the sidewall of the housing can greatly enlarge the air inlet area or air outlet area so as to enhance the heat-dissipating efficiency of the fan. In addition, the dimensions of the blades of the heat-dissipating fan can be enlarged along with the outward extension of the housing so that the airflow can be greatly increased and the heat-dissipating efficiency can be enhanced. Furthermore, the passage formed by the sidewall of the housing of the invention has a gradually reduced inner diameter formed from the inlet side to the outlet side (i.e., the formed passage has the inclined portion), and the air streams produced when the impeller rotates may be effectively concentrated to the central portion. Then, the air streams can directly flow toward the central portion of the heat sink having the highest temperature, and the heat-dissipating effects of the fan may be further enhanced. While the invention has been described by way of examples and in terms of preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. To the contrary, it is intended to cover various modifications. Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications.

A heat-dissipating device and a housing thereof. The housing includes a passage for guiding an air stream flowing from an opening to another opening, wherein an sidewall of the passage at least one of the opening sides extends radially outwards with a rotational axis of the heat-dissipating device or the passage so as to enlarge intake or discharge area for the air streams. Accordingly, the intake airflow rate may be greatly increased and the heat-dissipating efficiency of the heat-dissipating device may be greatly enhanced without changing assembling conditions with other elements.

big_patent

CROSS-REFERENCE TO RELATED APPLICATIONS This application is based upon and claims benefit of priority of Japanese Patent Applications No. Hei-9-160293 filed on Jun. 17, 1997 and No. Hei-10-146236 filed on May 27, 1998, the contents of which are incorporated herein by reference. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electroluminescent display panel, and more particularly to the one which is able to display images in different colors according to situations where the display is used. 2. Description of Related Art An example of the electroluminescent display panel of this kind is disclosed in JP-A-58-30093. In this display panel, a first luminescent layer of ZnS:TbF 3 for displaying images in green and a second luminescent layer of ZnS:SmF 3 for displaying images in red are laminated, with an insulation layer and an intermediate electrode disposed therebetween. When voltage is imposed on only the first luminescent layer, images are displayed in green, when voltage is imposed on only the second luminescent layer, images are displayed in red, and when voltage is imposed on both luminescent layers, images are displayed in a lemon color which is a mixture of green and red. This kind of display panel is suitable for use as an instrument panel for an automobile, which is able to display images in different colors in day time and in night time. Generally, it is desired to display images with a high luminance in day time, while it is desired not to display images in colors which include red in night time because red is a warning color and a driver feels uneasy with it. The display panel disclosed in the publication above is able to display images in red or lemon with a high luminance in day time by imposing voltage on both first and second luminescent layers, and to display images in green in night time by imposing voltage only on the first luminescent layer. Thus, the display panel fulfills the general requirement. However, it is necessary to provide an intermediate electrode between the first and second luminescent layers. The intermediate electrode makes the structure complex, and accordingly the display panel becomes expensive. SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problem, and an object of the present invention is to provide an electroluminescent display panel which is able to display different colors according to the situations without using the intermediate electrode. Another object of the present invention is to provide such a panel in which images are able to be selectively displayed in a color including no visible red components or in a color including visible red components with a high luminance. The electroluminescent display panel according to the present invention is composed of various layers laminated on a glass substrate. A first electrode layer, a first insulation layer, a first luminescent layer, a second luminescent layer, a second insulation layer and a second electrode layer are all laminated in this order on the glass substrate. The first and second electrode layers are for med into plural elongate stripes. The plural stripes of the first electrode layer are disposed perpendicularly to the plural stripes of the second electrode layer, so that cross-sections of the electrode stripes form a matrix. Each cross-section forms a picture element. Alternatively, both electrode layers are formed into patterns to be suitable for a pattern display. The first luminescent layer is made of a material which emits light including no visible red light components, and the second luminescent layer laminated on the first luminescent layer to cover a part thereof is made of a material which emits light including visible red light components. Preferably, the first luminescent layer is made of ZnS:Tb or ZnS:TbOF which emits green light, and the second luminescent layer is made of ZnS:Mn which emits orange light. The second luminescent layer partly overlaps the first luminescent layer, thereby forming a single layer portion and a double layer portion. The single layer portion emits green light at a low level voltage and the double layer portion emits lemon light which is a mixture of green and orange at a high level voltage. When the display panel is used as an instrument panel for an automobile, the green light display is used at night time and the lemon light display is used at day time. The green light is comfortable for a driver especially at night time, and the lemon light has a high luminance to cope with sun light at day time. Alternatively, the second luminescent layer may be eliminated, and, instead, a color filter such as a red color filter may be disposed to cover a part of the first luminescent layer. In this case, green light is emitted at a low voltage, and yellow light which is a mixed color of green and red is emitted at a high voltage. The electroluminescent display panel which is able to display different colors simply by changing the voltage level can be made in a simple structure and at a low cost. Other objects and features of the present invention will become more readily apparent from a better understanding of the preferred embodiments described below with reference to the following drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view schematically showing an electroluminescent display panel as a first embodiment of the present invention, taken along a line I--I in FIG. 2; FIG. 2 is a plan view showing the display panel shown in FIG. 1; FIG. 3 is a graph showing relation between driving voltage and luminance in the first embodiment; FIG. 4 is a graph showing relation between driving voltage and color purity in the first embodiment; FIG. 5 is a graph showing relation between a double layer proportion to a pixel and change of color purity in the first embodiment; FIG. 6 is a plan view showing an electroluminescent display panel as a second embodiment of the present invention; FIG. 7 is a cross-sectional view schematically showing an electroluminescent display panel as a third embodiment of the present invention; FIG. 8 is a cross-sectional view schematically showing an electroluminescent display panel as a fourth embodiment of the present invention; and FIG. 9 is a cross-sectional view schematically showing an electroluminescent display panel as a fifth embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An electroluminescent display panel as a first embodiment of the present invention will be described, referring to FIGS. 1 to 5. As shown in FIGS. 1 and 2, various layers constituting the display panel are laminated on a glass substrate 1. On the glass substrate 1, first electrodes 2 made of ITO having a thickness of 200 nm are formed. The first electrodes 2 are a plurality of stripes each extending in the X-axis direction as shown in FIG. 2. On the first electrodes 2, a first insulation layer 3 is formed. The first insulation layer 3 consists of a lower layer 31 made of SiO x N y having a thickness of 50-100 nm and a upper layer 32 which is a compound layer made of Ta 2 O 3 and Al 2 O 3 having a thickness of 200-300 nm. Both of the lower and upper layers 31, 32 are optically transparent. On the upper layer 32 of the insulation layer 3, a first luminescent layer 4 and a second luminescent layer 5 are formed. As shown in FIG. 2, the first luminescent layer 4 is uniformly formed as a single layer, while the second luminescent layer 5 is a plurality of stripes extending in the Y-axis direction. The width of the second luminescent layer 5 is about a half of the width of second electrodes 7. The first luminescent layer 4 is made of TbOF-added ZnS and has a thickness of 600 nm. The second luminescent layer 5 is made of Mn-added ZnS and has a thickness of 400 nm. On the first and second luminescent layers 4, 5, a second insulation layer 6 is formed to cover the luminescent layers. The second insulation layer 6 consists of three layers, a lower layer 61, a middle layer 62 and an upper layer 63. The lower layer 61 is made of Si 3 N 4 having a thickness of 100 nm. The middle layer 62 is a compound layer made of Ta 2 O 5 and Al 2 O 3 having a thickness of 200 nm. The upper layer 63 is made of SiO x N y having a thickness of 100 nm. All the materials of the second insulation layers are optically transparent. On the upper layer 63 of the second insulation layer 6, second electrodes 7 made of optically transparent ZnO and Ga 2 O 3 having a thickness of 450 nm are formed. The second electrodes 7 are a plurality of stripes extending in the Y-axis direction as shown in FIG. 2. The second electrodes 7 and the first electrodes 2 extending in the X-axis direction form a picture element or pixel matrix, each element of which is located at each crossing point of both electrodes 2, 7. As shown in FIG. 2, the first and second luminescent layers 4, 5 form a single layer portion 10 and a double layer portion 20. The single layer portion 10 is constituted by only the first luminescent layer 4, while the double layer portion 20 is constituted by both of the first and second luminescent layers 4, 5. The single layer portion 10 and the double layer portion 20 are aligned side by side as seen in FIG. 2. The threshold voltage with which the luminescent layers 4, 5 begin to emit light is determined depending on the layer thickness and properties of the material used. The threshold voltage VthS for the single layer portion 10 and the threshold voltage VthD for the double layer portion 20 are expressed in the following formulae. VthS=Ea1{ta1+ti·(.di-elect cons.a1/.di-elect cons.i)}(1) VthD=Ea1·ta1+Ea2·{ta2+ti·(.di-elect cons.a2/.di-elect cons.i)} (2) where: Ea1: clamp electric field intensity of the first luminescent layer 4; ta1: thickness of the first luminescent layer 4; .di-elect cons.a1: relative dielectric constant of the first luminescent layer 4; Ea2: clamp electric field intensity of the second luminescent layer 5; ta2: thickness of the second luminescent layer 5; .di-elect cons.a2: relative dielectric constant of the second luminescent layer 5; ti: thickness of the insulation layer; .di-elect cons.i: relative dielectric constant of the insulation layer; As seen from the formulae, the threshold voltage VthS of the single layer portion 10 increases as the first luminescent layer 4 becomes thicker, and the threshold voltage of the double layer portion 20 increases as both of the first and second luminescent layers 4, 5 become thicker. The difference between both threshold voltages is expressed as follows: VthD-VthS=Ea2·ta2+(.di-elect cons.a2·Ea2-.di-elect cons.a1·Ea1)·(ti/.di-elect cons.i) (3) If the first and second luminescent layers 4, 5 are designed so that (.di-elect cons.a2·Ea2-.di-elect cons.a1·Ea1)≧0, then the threshold voltage difference (VthD-VthS) is always positive and becomes larger as the thickness of the second luminescent layer becomes thicker. If the first and second luminescent layers 4, 5 are designed so that (.di-elect cons.a2·Ea2-.di-elect cons.a1·Ea1)<0, then the threshold voltage difference (VthD-VthS) is positive only if the following relation exist: Ea2·ta2>(.di-elect cons.a1·Ea1-.di-elect cons.a2·Ea2)·(ti/.di-elect cons.i), that is, ta2>(.di-elect cons.a1·Ea1-.di-elect cons.a2·Ea2)·(ti/.di-elect cons.i)/Ea2 The thickness ti of the insulation layer in the formulae above is a total thickness of all the insulation layers 31, 32, 61, 62 and 63, when the same material is used for all of them. On the other hand, if respectively different materials are used, the value ti/.di-elect cons.i is expressed as follows: (ti/.di-elect cons.i)=Σ(ti.sub.n /.di-elect cons.i.sub.n) where ti n is a thickness of respective insulation layers, and .di-elect cons.i n is a relative dielectric constant of respective insulation layers. The respective values Ea1, ta1, .di-elect cons.a1, Ea2, ta2, .di-elect cons.a2, ti n and .di-elect cons.i n in the embodiment described above and shown in FIGS. 1 and 2 are as follows: Ea1 (clamp electric field intensity of the first luminescent layer 4): about 1.8 [MV/cm]; ta1 (thickness of the first luminescent layer 4): 600 [nm]; .di-elect cons.a1 (dielectric constant of the first luminescent layer 4): about 9.0; Ea2 (clamp electric field intensity of the second luminescent layer 5): about 1.7 [MV/cm]; ta2 (thickness of the second luminescent layer 5): 400 [nm] .di-elect cons.a2 (dielectric constant of the second luminescent layer): about 10.0; ti 1 (thickness of the insulation layer 31): 100 [nm]; ti 2 (thickness of the insulation layer 32): 300 [nm]; .di-elect cons.i 1 (dielectric constant of the layer 31): about 7.6; .di-elect cons.i 2 (dielectric constant of the layer 32): about 27.0; ti 3 (thickness of the insulation layer 61): 100 [nm]; ti 4 (thickness of the insulation layer 62): 200 [nm]; ti 5 (thickness of the insulation layer 63): 100 [nm]; .di-elect cons.i 3 (dielectric constant of the layer 61): about 8.0; .di-elect cons.i 4 (dielectric constant of the layer 62): about 27.0; and .di-elect cons.i 5 (dielectric constant of the layer 63): about 7.6 Accordingly, the value (ti/.di-elect cons.i) is calculated as follows: (ti/.di-elect cons.i)=100/7.6+300/27+100/8.0+200/27+100/7.6≈57.3 The threshold voltage VthS of the single layer portion 10 is calculated according to the formula (1): VthS=1.8[MV/cm]×(600[nm]+9.0×57.3[nm])=200.8[V] The threshold voltage VthD of the double layer portion 20 is calculated according to the formula (2): VthD=1.8[MV/cm]×600[nm]+1.7[MV]×(400[nm]+10.0×57.3[nm])=273.4[V] Therefore, the difference between both threshold voltages is: VthD-VthS=273.4[V]-200.8[V]=72.6[V] The relation between driving voltage and luminance for both of the single layer portion 10 and the double layer portion 20 is shown in FIG. 3. The single layer portion 10 starts to emit light when the driving voltage imposed between the first and second electrodes 2, 7 reaches its threshold voltage of 200.8 V (at point a), and its luminance rapidly increases as the driving voltage increases, as shown by a dotted line. The double layer portion 20 starts to emit light when the driving voltage reaches its threshold voltage of 273.4 V (at point b), and its luminance rapidly increases as the driving voltage increases, as shown by a solid line. At point c between points a and b, the luminance of the single layer portion 10 reaches a predetermined level of green light. At point d, the luminance of the double layer portion 20 reaches a predetermined level of lemon color light which is a mixture of green light from the first luminescent layer 4 and orange light from the second luminescent layer 5. A total luminance of the display panel is low at point c, and high at point d, because only the first luminescent layer 4 emits light at point c while both luminescent layers 4 and 5 emit light at the point d. The display panel is driven by the driving voltage at the vicinity of point c in night time, and at the vicinity of point d in day time. Therefore, images are displayed in green which is tender to driver's eyes in night time, while images are displayed in a lemon color having a high luminance to cope with sun light in day time. FIG. 4 shows relation between the driving voltage and color purity (coordinate Y). As seen in the graph, the color purity changes from 0.61 which represents green to 0.47 which represents yellow by sweeping the driving voltage from about 200 V to about 350 V. Thus, the display panel according to the present invention is able to change the display color only by changing the driving voltage. In addition, the color purity can be also changed by selecting the width of the second luminescent layer 5. For example, as the width of the second luminescent layer 5 becomes narrower, the display color changes from green to yellow-green only in a smaller range, because the display in green becomes predominant. On the other hand, the width of the second luminescent layer 5 is wider, the display 5 color changes from green to lemon in a wider range. FIG. 5 shows a range of color purity change when the double layer proportion to a pixel (one picture element) is changed. A ratio of the surface area of the double layer portion 20 to the surface area of the pixel (a double layer proportion) is shown on the abscissa, and a range of color purity change is shown on the ordinate. The range of color purity change is measured for samples each having a respective double layer proportion (0%-80%) by applying a driving voltage which is 40 V higher than the threshold voltage of the single layer portion (VthS) and another driving voltage which is 40 V higher than the threshold voltage of the double layer portion (VthD). As seen from the graph in FIG. 5, the range of color purity change is maximum when the double layer proportion is 50%. When the double layer proportion is 30% to 80%, the range of color purity change is higher than 0.15. If the range is higher than 0.15, the color change is clearly recognized by a viewer. The color purity change can be also varied by changing the thickness of the second luminescent layer 5. For example, the color purity change becomes larger for a given range of the driving voltage when the thickness of the second luminescent layer 5 is made thinner, because the difference between threshold voltages VthD and TthS becomes smaller. On the contrary, as the thickness of the second luminescent layer 5 becomes thicker, the color purity change becomes smaller, because the difference between VthD and VthS becomes larger. Now, manufacturing processes of the electromagnetic display panel described above will be briefly explained. An uniform ITO layer is formed on the glass substrate 1 by DC sputtering. The ITO layer is etched into stripes to form the first electrodes 2. Then, the lower layer 31 made of SiO x N y and the upper layer 32 made of Ta 2 O 5 containing 6 wt % of Al 2 O 3 are formed on the first electrodes 2 by sputtering. More particularly, mixture gas containing Ar, N 2 and small amount of O 2 is introduced into a sputtering device, while keeping the glass substrate 1 therein at 300° C., and the mixture gas is kept at 0.5 Pa. The lower layer 31 is formed by 3 KW high frequency power using Si as a target. Then, the upper layer 32 is formed by 4 KW high frequency power, using Ar and O 2 kept at 0.6 Pa as a sputtering gas and a sintered compound target containing Ta 2 O 5 and 6 wt % of Al 2 O 3 . Then, the first luminescent layer 4 made of ZnS as a mother material and TbOF as a luminescent center is formed uniformly on the upper layer 32. More particularly, the glass substrate 1 is kept at 250° C., Ar and He kept at 3.0 Pa are used as a sputtering gas, and 2.2 KW high frequency power is used for sputtering. Then, the second luminescent layer 5 made of ZnS as a mother material and Mn as a luminescent center is formed uniformly on the first luminescent layer 4. More particularly, the second luminescent layer 5 is formed by electron beam vapor deposition with a deposition speed of 0.1-0.3 nm/sec, while the glass substrate 1 is kept at a constant temperature in a vapor deposition device having a pressure lower than 5×10 -4 Pa. Then, the uniformly made layer is dry-etched into a plurality of stripes. The dry-etching is performed in an RIE device containing a mixture gas of Ar and CH 4 maintained under a pressure of 7 Pa, while keeping the glass substrate 1 at 70° C., by using 1 KW high frequency power. Then, the first and second luminescent layers 4, 5 are heat-treated under vacuum at a temperature of 400-600° C. Then, the lower layer 61 made of Si 3 N 4 , the middle layer 62 made of Ta 2 O 5 containing 6 wt % of Al 2 O 3 , and the upper layer 63 made of SiO x N y are formed on the luminescent layers 4, 5 in this order in the same manner as layers constituting the first insulation layer 3. However, the lower layer 61 made of Si 3 N 4 is formed without using O 2 in the sputtering gas as opposed to the layer made of SiO x N y . Finally, the second electrodes 7 made of ZnO:Ga 2 O 3 is formed uniformly on the upper layer 63 of the second insulation layer 6. The second electrodes 7 is formed by ion plating, using a pellet made of a mixture of ZnO powder and Ga 2 O 3 as a deposition material. More particularly, the glass substrate 1 is kept at a constant temperature in an ion plating device containing Ar gas under a constant pressure. Beam power and high frequency power are controlled so that the deposition speed becomes in a range of 6-18 nm/min. The layer made uniformly is etched into a plurality of stripes. Thus, the electroluminescent display device shown in FIGS. 1 and 2 are completed. FIG. 6 shows a second embodiment of the present invention, in which the double layer portion 20 is made in a square shape, which is orthomorphic to the shape of the picture element, each square being separated from each other as opposed to a stripe shape in the first embodiment. The display will be more comfortable to a viewer, because both of the picture element and the double layer portion 20 are orthomorphic. FIG. 7 shows a third embodiment of the present invention, in which a red color filter 8 is additionally disposed on the second electrodes 7. Other structures are the same as those of the foregoing embodiments. Red light is emitted through the red color filter 8, though the double layer portion 20 emits lemon color light. When the display panel is driven at a high luminance, the light emitted from the panel is, as a whole, yellow which is a mixed color of green from the single layer portion 10 and red from the red color filter 8. The red color filter 8 may be replaced by other color filters such as a green or blue filter. It is also possible to dispose a color filter to match the single layer portion 10. For example, a blue color filter may be disposed on the second electrodes 7 to cover the single layer portion 10. In this case, the display color is blue at the low luminance and white, which is a mixed color of blue and yellow, at the high luminance. FIG. 8 shows a fourth embodiment of the present invention, in which the second luminescent layer 5 of the third embodiment shown in FIG. 7 is eliminated. Other structures are the same as those of the foregoing embodiments. Red light is emitted through the red color filter 8 at the high luminance operation and green light is emitted from other portions not covered by the red color filter 8. Therefore, display color is green at the low luminance and yellow, which is a mixed color of green and red, at the high luminance. In place of the red color filter 8, other color filters may be used. For example, if a blue color filter is used, display color is green at the low luminance and blue-green at the high luminance. FIG. 9 shows a fifth embodiment of the present invention, in which the first luminescent layer 4 of the fourth embodiment shown in FIG. 8 is modified. Other structures are the same as those of the foregoing embodiments. A plurality of thicker portions 4a are formed on the first luminescent layer 4. The red color filter 8 is disposed on the second electrodes 7 to cover the thicker portions 4a. The thicker portions 4a emit light having a higher luminance when a higher driving voltage is imposed. Therefore, luminance attenuation by the red color filter 8 can be compensated. The thicker portions 4a may be stripe-shaped or square-shaped. If they are square, a more comfortable display to a viewer will be realized as is done in the second embodiment. The embodiments described above may be modified in various ways. For example, the material to be added as a luminescent center to the mother material ZnS in the first luminescent layer 4 is not limited to TbOF, but other materials such as TbF 3 or TbCl 3 may be used. Also, the material to be used as a luminescent center in the second luminescent layer 5 is not limited to Mn, but other materials such as MnF 2 or MnCl 2 may be used. The materials used for the first and second luminescent layers 4, 5 including the mother material in the first, second and third embodiments may be changed to other materials. For example, the first luminescent layer 4 may be made of SrS:Ce. In this case, blue-green light is emitted from the single layer portion 10. Similarly, the material used for the first luminescent layer 4 in the fourth and fifth embodiments may be changed to other materials which do not emit light including a red light component. In the embodiments having the red color filter 8, resin containing black pigment may be coated on the bottom surface of the glass substrate 1. By doing this, the red color filter 8 itself becomes difficult to be seen by a viewer, and accordingly the display becomes more natural. In addition, the red color filter 8 may be formed with a resist filter which is made by dispersing red dyestuff or pigment into organic solvent. Though the embodiments described above have a pixel matrix formed by the first and second electrodes both of which are stripe-shaped, the electrodes may be shaped in a certain pattern to realize a pattern display. While the present invention has been shown and described with reference to the foregoing preferred embodiments, it will be apparent to those skilled in the art that changes in form and detail may be made therein without departing from the scope of the invention as defined in the appended claims.

An electroluminescent display panel which is able to selectively display different colors by changing a voltage level imposed thereon is made in a simple structure. A first luminescent layer (4) emitting green light, for example, and a second luminescent layer (5) emitting orange light, for example, are directly laminated on each other without interposing an intermediate electrode therebetween. The second luminescent layer covers only a part of the first luminescent layer to form a single layer portion and a double layer portion. The single layer portion emits green light at a low voltage level, while the double layer portion emits lemon light having a higher luminance at a high voltage level. The display may be made in a form of a matrix or a certain pattern. The display panel may be used as an instrument panel for an automobile. The green light display is used at night time, while the lemon light display with a high luminance is used at day time to cope with sun light.

big_patent

[0001] This application is a continuation of, and claims priority to each of, U.S. patent application Ser. No. 14/081,830, filed on Nov. 15, 2013, and entitled “A COMMUNICATIONS TERMINAL, A SYSTEM AND A METHOD FOR INTERNET/NETWORK TELEPHONY,” which is a continuation of U.S. patent application Ser. No. 13/360,574, filed on Jan. 27, 2012 (issued as U.S. Pat. No. 8,611,328 on Dec. 17, 2013), and entitled “A COMMUNICATIONS TERMINAL, A SYSTEM AND A METHOD FOR INTERNET/NETWORK TELEPHONY,” which is a divisional of U.S. patent application Ser. No. 12/153,062, filed on May 13, 2008 (issued as U.S. Pat. No. 8,107,449 on Jan. 31, 2012), which is a continuation of U.S. patent application Ser. No. 11/711,009, filed Feb. 27, 2007, (issued as U.S. Pat. No. 7,408,915 on Aug. 5, 2008), which is a continuation of U.S. patent application Ser. No. 10/362,508, filed Feb. 25, 2003 (issued as U.S. Pat. No. 7,187,670 on Mar. 6, 2007), which is a national stage entry of PCT Patent Application No. PCT/DK01/00571, filed Sep. 3, 2001, which claims priority to Denmark Patent Application No. PA 2000 01308, filed Sep. 1, 2000, the entireties of each of which applications are hereby incorporated by reference herein. BACKGROUND [0002] This invention relates to an electronic portable communications terminal for Internet/network telephony. The invention also relates to a system for Internet/network telephony and to a method for the same. [0003] The invention additionally relates to a computer-readable medium comprising a program which may be caused to execute the method of the invention on one or more computers or CPUs. [0004] Telephony via the Internet (IP telephony) is a very low-cost alternative to ordinary telephony, in particular over long distances. Such systems convert the speech information into and from a suitable digital format, which is divided into data packets that are transported via the Internet itself, the actual transport via the Internet being typically at a fixed price. [0005] Moreover, IP telephony may also be used for communication with a stationary conventional telephone coupled to the existing telephone network, as the Internet may be used for transmitting data to a local gateway which is connected to the existing public switched telephone network (PSTN). Thus, the user need just pay a local telephone charge even for long distance calls, as the Internet is used for the transport of data to the gateway/location concerned. [0006] Such IP telephony systems/solutions will undoubtedly become more attractive as more and more people get access to the Internet and/or are connected in networks, and as the supply of fixed charge, free, permanent and broadband solutions in connection with the Internet and/or other networks gets greater. [0007] Patent publication WO 00/51375 discloses a communication system where a dual-mode device is capable of both cell phone communication and telephone communication on a IP LAN/network. The dual-mode device connects to the LAN/network either via a cable connecting directly to the LAN/network or a cable connecting to a wireless communication device in wireless communication with a wireless LAN/network. The establishment of a connection to the LAN/network is troublesome since a cable is used and restricts the movement of the user when the dual-mode device is being used and requires for special equipment at the connecting point in the case of a wireless LAN/network. [0008] Additionally, the support of both communication formats causes the dual-mode device to be of a complicated and more expensive design with a relative large power usage. [0009] Patent Publication WO 98/57508 relates to a system for wireless communication via a DECT terminal and a base station, such as e.g. a digital wireless telephone connected to a base station. The system uses the IP protocol for passing on digital speech information via the Internet between various base stations (DECT islands), so that a given DECT terminal will receive a call at the base station at which the terminal is present. This provides increased mobility, as the terminal may be used at other base stations. [0010] A gateway (GW) constitutes the very interface to the DECT base station and handles the conversion of telephone numbers into IP addresses, as the DECT terminal itself does not know its IP address which must be unique. Further, the DECT terminal(s) has to be known, identified and/or paired beforehand with the base station in order to establish communication. [0011] Patent Publication WO 99/38311 relates to a system and a corresponding method of providing a wireless RF (Radio Frequency) interface between one or more terminals and an Internet Protocol (IP)/Internet telephone system, so that the terminals may be used for telephony via the Internet. The system uses a base station which partly handles and controls the distribution of information to the various terminals and partly handles the access to the Internet, which means that the base station controls/contains the relevant protocols inter alia in connection with the Internet. [0012] Further, a terminal associated with a given base station cannot readily be used in connection with another base station, as the base station must know the number of terminals in order to allocate to each terminal its unique frequency and/or jump frequency for use in communication, so that the correct information is received/transmitted by the correct terminal. [0013] The two above-mentioned systems both have the drawback that they require a specialized type of equipment (base station, gateway, etc.), which is a great obstacle to the flexibility with respect to mobility and updating/expansion of functionality, since the specialized equipment must be physically present at every single location where the terminals are contemplated for use. SUMMARY [0014] An object of the invention is to provide a communications terminal which uses a network and/or the Internet for transferring information/data representing digitized speech, sounds, music, etc. [0015] Another object of the invention is to provide a communications terminal which increases the flexibility with respect to wireless communication/connection with a network and/or the Internet. [0016] A further object of the invention is to provide a communications terminal which does not need specialized equipment and functionality to provide a connection to a network and/or the Internet. [0017] Still a further object of the invention is to enable flexibility with respect to functionality. [0018] Yet another object is to provide a communications terminal enabling relative simple design, small size, and relative low/reduced power consumption. [0019] These objects, among others, are achieved by an electronic portable communications terminal for Internet/network telephony comprising [0020] audio means adapted to reproduce sound on the basis of a first electrical signal and to record sound resulting in a second electrical signal, [0021] converting means adapted to convert said second electrical signal into transmission data, representing sound for transmission, in a suitable data format, and to convert received data, representing received sound, in said suitable data format into said first electrical signal, and [0022] protocol means adapted to handle and control communication of said received and transmission data in accordance with a standardized Internet/network protocol, such as e.g. TCP/IP, thereby embedding and extracting said transmission and received data, respectively, in a data packet format, [0023] wherein said terminal further comprises [0024] wireless communications means for wireless near field communication of said received and/or transmission data in a wireless data format with a connecting unit adapted to establish a connection to a network and/or the Internet according to said standardized Internet/network protocol, where the wireless communications means is further adapted to [0025] embed/extract packets of said data packet format in/from said wireless data format. [0026] A portable communications terminal is achieved hereby which provides telephony via a network or the Internet, which gives a considerable economic advantage. [0027] The communications terminal establishes a wireless connection to a connecting unit which establishes a connection to the relevant network. [0028] In addition, a communications terminal is provided which can independently control and communicate data packets according to a standardized Internet/network protocol such as e.g. the TCP/IP protocol. This makes it possible to use simplified standardized equipment, which must merely be capable of establishing a connection to a given network and/or the Internet. The wireless connection is just used for transferring the data packets to the connecting unit in an expedient manner. [0029] In this way a terminal according to the invention may be used for Internet telephony, if just it is in the vicinity of standardized equipment allowing the set-up of a network and/or Internet connection. The local handling of the IP protocol also makes it easier to use the terminal in connection with “foreign” connecting units, since a configuration will be considerably easier and can be made automatically in certain types of wireless protocols. [0030] Also provided is the option of dynamic allocation of a useful IP address via the protocol means, as a valid IP address for a given session (i.e. communication) may be allocated to the communications terminal. This results in even greater mobility, as the allocation may take place in dependence on the connecting unit with which the wireless connection is established, since the protocol means are present in the terminal itself. A user would be capable of receiving and transmitting a call regardless of the specific location as long as there is Internet/network access. [0031] It is moreover ensured that the handling and functionality of several terminals are facilitated considerably, since e.g. a central database can relate unique and fixed addresses to users of the terminals, i.e. a local unique address is related to a temporary IP-address. A example of a local unique address may be the unique 48-bit address used in the Bluetooth protocol, a telephone number, etc. [0032] Additionally, since only communication means for near field communication needs to be present, i.e. no other communication means like cellular communication means, etc., a relative low complexity and power consumption is obtained and a relatively small size of the terminal is made possible thereby making is very suitable for wearing and/or carrying by a user. [0033] Preferably, the wireless data format is a Bluetooth data format. [0034] In a preferred embodiment, said terminal is adapted to communicate additional information and/or data with said connecting unit, wherein said additional information and/or data comprises one or more of: [0035] an IP address of a communication receiver, [0036] an IP address of a communication transmitter/said terminal, [0037] an IP address of at least one connecting unit, [0038] an IP address of a service server, [0039] TCP/IP packets, [0040] speech mails, [0041] commercials, [0042] music, [0043] stock exchange and financial news [0044] chat-lines, [0045] chat-rooms, [0046] telephone meetings. [0047] Relevant information may be sent in this way together with the transmitted speech information, whereby various functionalities may be provided, optionally in dependence on a user profile. [0048] In a preferred embodiment, said terminal is adapted to establish a connection to a service server on said network and/or the Internet via the connecting unit, so that information concerning a desired communication receiver may be transferred to the server, said server being adapted to pass on information concerning the IP address of the desired communication receiver and/or to provide a direct connection between the desired communication receiver and a communication transmitter/said terminal. [0049] Hereby, a central server can keep track of which terminals are accessible and where, so that a user wishing to make a call is merely to know an alias, a nickname, the IP address, etc. of the user whom it is desired to contact. [0050] In a further embodiment, said terminal comprises speech recognition means adapted to analyze and interpret said sound for recording and/or said transmission data to identify one or more commands. [0051] This makes the terminal easier to operate for a user, and the physical dimensions of the terminal itself may be reduced, as operating buttons, etc. can be avoided completely or reduced greatly in numbers. [0052] In an embodiment, said near field communications means for near field communication are adapted to communicate in the form of one or more of: [0053] an RF communications protocol such as e.g. Bluetooth, DECT, etc., [0054] an infrared communications protocol, or [0055] another wireless communications protocol. [0056] In an embodiment, said suitable data format is a compressed data format. This provides a better/optimal utilization of the available bandwidth on the network and/or the Internet used, as the data packets/the digital information are/is compressed prior to transmission. [0057] In a preferred embodiment, said terminal is an ear telephone which comprises means for capturing sound for said recording via the cheekbone and the soft tissue in the auditory canal of a user. Alternatively, the terminal comprises means for capturing sound via a boom microphone. [0058] This provides a very discrete, compact and hands-free or minimally hand-operated communications terminal of a small physical size. An example of an ear telephone that may be used in connection with the present invention is disclosed in the European Patent Application EP 0 673 587 incorporated herein by reference. [0059] In another preferred embodiment, the terminal is a headset comprising a housing comprising the converting means, the wireless communication means, and the protocol means, an earpiece secured to the housing comprising means for reproducing sound on the basis of the first electrical signal, a brace secured to the housing at one end and with a sound capturing unit for capturing sound for transmission in the form of a second electrical signal located at the other end of the brace, thereby allowing for easy carrying and use of the terminal and providing a very discrete, compact and hands-free or minimally hand-operated communications terminal of a small physical size. [0060] In one embodiment the headset also comprises a second brace, spring, arm, etc. secured to the housing which may stabilises and secures the headset to a user's head by being adapted to engage the user's ear. [0061] A further object of the invention is to provide a system which has the above-mentioned advantages and accomplishes the above-mentioned objects. [0062] This is achieved by a system for Internet telephony, said system comprising [0063] a portable communications terminal according to one or more of the above embodiments, [0064] a connecting unit adapted to establish a connection to a network and/or the Internet, [0065] a service server connected to the Internet and/or a network, said server comprising one or more databases comprising information related to potential desired communication receivers and/or transmitters, said server being adapted to pass on information concerning the IP address of a desired communication receiver and/or establish a direct connection between the desired communication receiver and a communication transmitter/said terminal. [0066] A system is achieved hereby wherein a central service server can handle and control the connection between a large number of users. Further, also the option of further functionality is provided, e.g. in the form of news, reading of mails, speech mails, commercials, music, stock exchange and financial news, etc., which may be transmitted to a user of the system, e.g. depending on a user profile. Moreover, it is possible to provide functionalities, such as chat-lines, chat-rooms, telephone meetings, etc., where several terminals/users can communicate with each other so that everybody can hear what everybody says. [0067] In an embodiment, the system additionally comprises speech recognition means adapted to analyse and interpret data representing sound to identify one or more commands. Speech recognition may be achieved hereby without necessarily having them placed in a terminal according to the invention, which is a great advantage since speech recognition requires relatively great resources of processor power and storage capacity. [0068] A further object of the invention is to provide a method and embodiments thereof enabling the same possibilities and the same advantages as are provided by the embodiments of the communications terminal described above. [0069] This is achieved by a method for Internet/network telephony comprising the steps of [0070] reproducing sound on the basis of a first electrical signal and recording sound resulting in a second electrical signal, by audio means, [0071] converting said second electrical signal into transmission data, representing sound for transmission, in a suitable data format, and converting received data, representing received sound, in said suitable data format into said first electrical signal, by converting means, and [0072] handling/control of communication with said received and transmission data in accordance with a standardized Internet/network protocol, such as e.g. TCP/IP, and embedding and extracting said transmission and received data, respectively, in/from a data packet format according to said standardized Internet/network protocol, by protocol means, [0073] wherein the method further comprises the steps of [0074] wireless near field communication of said received and/or transmission data in a wireless data format with a connecting unit adapted to establish a connection to a network and/or the Internet according to said standardized Internet/network protocol [0075] embedding/extracting packets of said data packet format in/from said wireless data format. [0076] In an embodiment, said method communicates additional information and/or data with said connecting unit, and said additional information and/or data comprises one or more of: [0077] an IP address of a communication receiver, [0078] an IP address of a communication transmitter/said terminal, [0079] an IP address of at least one connecting unit, [0080] an IP address of a service server, [0081] TCP/IP packets, [0082] speech mails, [0083] commercials, [0084] music, [0085] stock exchange and financial news, [0086] chat-lines, [0087] chat-rooms, [0088] telephone meetings. [0089] In a further embodiment, said method establishes a connection to a service server on said network and/or the Internet via said connecting unit, so that information concerning a desired communication receiver may be transferred to the server, said server being adapted to pass on information concerning the IP address of the desired communication receiver and/or to establish a direct connection between the desired communication receiver and a communication transmitter/said terminal. [0090] In another embodiment, said method comprises speech recognition for analysis and interpretation of said sound for recording and/or said transmission data to identify one or more commands. [0091] In still another embodiment, said communications means for near field communication communicates in the form of one or more of: [0092] an RF communications protocol such as e.g. Bluetooth, DECT or the like, [0093] an infrared communications protocol, or [0094] another wireless communications protocol. [0095] In an embodiment, said suitable data format is a compressed data format. [0096] In one embodiment, the method is used in an ear telephone which comprises means for capturing sound for said recording via the cheek-bone and the soft tissue in the auditory canal of a user. [0097] In one embodiment, the method is used in a headset comprising a housing comprising converting means, wireless near-field communication means, and protocol means, an earpiece secured to the housing comprising means for reproducing sound on the basis of the first electrical signal, a brace secured to the housing at one end and with a sound capturing unit for capturing sound for transmission in the form of a second electrical signal located at the other end of the brace. [0098] The invention additionally relates to a computer-readable medium comprising a program written thereon, wherein the program, when being executed, causes the computer to perform the method according to the present invention. [0099] The computer-readable medium may be a suitable volatile nor non-volatile medium, such as e.g. a CD-ROM, a magnetic disc, a ROM circuit, a network connection or generally any other medium which can provide a computer system with information on how instructions/commands are to be performed/executed. BRIEF DESCRIPTION OF THE DRAWINGS [0100] The invention will be explained more fully below with reference to the drawing, in which [0101] FIG. 1 shows a schematic block diagram of a communications terminal according to an embodiment of the invention; [0102] FIG. 2 a illustrates a system according to the invention in which two communications terminals and a service server are shown; [0103] FIG. 2 b illustrates the system according to the invention in which another type of connecting unit is shown; [0104] FIG. 2 c illustrates the system according to the invention in which a user connected to the traditional telephone network (PSTN) is shown; [0105] FIGS. 3 a and 3 b illustrates a flowchart of an embodiment of the method according to the invention; [0106] FIG. 4 shows a preferred embodiment of a communications terminal according to the invention; and [0107] FIG. 5 shows a perspective view of an alternative preferred embodiment of a communications terminal according to the invention. DETAILED DESCRIPTION OF EMBODIMENTS [0108] FIG. 1 shows a schematic block diagram of a communications terminal ( 100 ) according to an embodiment of the invention. Shown schematically in the figure are audio means ( 101 ) e.g. in the form of some type of loudspeaker, sound generator, transducer, etc., and some type of microphone, transducer or other sound capturing unit. [0109] The audio means ( 101 ) are used for playing/reproducing received sound information, such as e.g. speech, music, etc., in the form of a first electrical signal, and for capturing sound for transmission in the form of a second electrical signal, respectively. [0110] Also shown are converting means ( 102 ) which convert the second electrical signal into a suitable digital sound format suitable for transmission. The converting means ( 102 ) also convert received sound data in the suitable digital sound format into the first electrical/analog signal prior to playing via the loudspeaker, sound generator, transducer, etc. [0111] The converting means ( 102 ) comprise A/D and D/A converters and/or a codec (coder and decoder) for converting between analog and digital sound. If a codec is used, the digitized data may be compressed so that the amount of data to be transmitted and received is reduced considerably. [0112] The suitable digital sound format may e.g. be raw data, ADPCM, DTMF, PCM, Way, MP3 and other suitable digital sound formats, and several formats may e.g. be supported at the same time. Additionally, e.g. also one or more streaming sound/audio formats might be supported in the converting means ( 102 ). [0113] The converting means ( 102 ) are connected to protocol means ( 103 )/a protocol stack which provide for the handling of data/information in connection with transmission and reception of data. The protocol which is preferably used is the TCP/IP (Transmission Control Protocol/Internet Protocol) suit of protocols e.g. including PPP (Point-to-Point Protocol). The IP protocol part provides for the actual handling of data in the form of splitting or collection of the digital information in data packets as well as handling of receiver and transmitter information (in the form of IP addresses), while the TCP protocol part provides for the actual handling of the connection between receiver and transmitter. [0114] The protocol means ( 103 ) may e.g. be comprised by a special- and/or general-purpose microprocessor, logic circuit, etc. [0115] The protocol means ( 103 ) are connected to wireless communications means ( 104 ), which receive digitized sound/data in the form of IP packets from the protocol means ( 103 ) via a bus between the protocol means ( 103 ) and the wireless communication means ( 104 ) (e.g. under the control or via the microprocessor ( 105 ), as shown in FIG. 1 . The aerial, antenna, etc. ( 106 ) is used for the wireless transmission with a connecting unit. This is for further wireless transmission. The communications means ( 104 ) also receive wireless data which are transmitted to the protocol means in the form of IP packets for further processing and playing via the converting means ( 102 ) and the audio means ( 101 )/loudspeaker/sound generator. [0116] The information which the communications means ( 104 ) receive or are to transmit, is typically embedded in a suitable format. So in this case the IP packets are embedded in a transmission format in accordance with wireless communication protocol e.g. also embedded in a packet format. [0117] Preferably, the communications means ( 104 ) use an RF (Radio Frequency) connection in accordance with e.g. Bluetooth, DECT, IEEE802.11 or other wireless protocols. Bluetooth is especially advantageous for portable terminals since it is designed with low power consumption in mind. Alternatively, also infrared wireless communications protocols may be used. [0118] The communications terminal ( 100 ) also comprises a calculating/processing unit, such as a CPU, microprocessor or the like, for controlling and coordinating the various parts. Preferably, the microprocessor ( 105 ) is connected to one or more memory elements (not shown), such as e.g. RAM, Flash, ROM, etc., for storage and provision of relevant information. In an alternative embodiment, the microprocessor ( 105 ) and the protocol means ( 103 ) is comprised in a single microprocessor unit. [0119] That the terminal ( 100 ) contains protocol means ( 103 ) for handling/control allows the use of simplified standardized connection/coupling equipment, which must merely be capable of establishing a connection to a given network and/or the Internet, and the local handling of the IP protocol also makes it easier to use the terminal ( 100 ) in connection with “foreign” connecting units, since a configuration is considerably easier and may be made automatically in certain types of wireless protocols. The only requirement is the same RF communication system in the terminal and connection/coupling equipment with access to the Internet/a network. [0120] In an alternative embodiment, the terminal ( 100 ) also comprises speech recognition means e.g. implemented via the microprocessor ( 15 ) and/or implemented via specialized hardware, so that the terminal ( 100 ) may be operated hands-free in case of spoken commands. Additionally/alternatively, the terminal comprises one or more operating means like buttons, switches, etc. [0121] The terminal ( 100 ) also comprises an energy/power source (not shown) like one or more batteries. [0122] FIG. 2 a illustrates a system according to the invention where two communications terminals ( 200 ; 200 ′) and a service server ( 210 ) are shown. The figure illustrates how two users ( 201 ; 201 ′) are interconnected via the communications terminals ( 200 ; 200 ′) according to the invention. [0123] The terminals ( 200 ; 200 ′) are illustrated in the figure as a preferred embodiment, both in the form of an ear telephone which will be explained more fully in connection with FIG. 4 . [0124] An alternative preferred embodiment of a terminal ( 200 ; 200 ′) is explained in connection with FIG. 5 . [0125] The figure just shows two users ( 201 ; 201 ′) for clarity, but in practice a much larger number of users will be connected to the system at the same time. [0126] Each terminal ( 200 ; 200 ′) is connected to the Internet ( 220 ) and/or another network, such as e.g. a local network or intranet in a company, household, etc. via a connecting unit ( 202 ; 202 ′). The connecting units ( 202 ; 202 ′) are equipped with a wireless communications module/a transceiver ( 203 , 203 ′), such as e.g. a Bluetooth module or the like, so that a wireless communications link is established between a given connecting unit ( 202 ; 202 ′) and a given terminal ( 200 ; 200 ′). [0127] Several users ( 201 ; 201 ′) may also be connected to the same wireless communications module/the same transceiver ( 203 ; 203 ′). [0128] The connecting units ( 202 ; 202 ′) may e.g. be a standard computer, PDA, a mobile telephone etc. with Internet connection, preferably a broadband connection. [0129] The system additionally comprises one or more service servers ( 210 ) likewise connected to the Internet/network ( 220 ). The service server ( 210 ) comprises one or more databases ( 211 ) where relevant information concerning the users ( 201 ; 201 ′) of the system is saved. [0130] The database ( 211 ) comprises information such as e.g. one or more user aliases per user ( 201 ; 201 ′) and associated current IP addresses. The IP addresses may either be static (e.g. if the user ( 201 ; 201 ′) is connected to a company network) or dynamic, where an IP address is allocated to the user (or rather the terminal ( 200 ; 200 ′) each time the user ( 201 ; 201 ′) connects to the system. [0131] The server can thus keep track of which terminals ( 200 ; 200 ′)/users ( 201 ; 201 ′) are accessible and where. [0132] The service server ( 210 ) additionally comprises at least one router ( 212 ) which establishes the connection between users ( 201 ; 201 ′) who have wanted contact. [0133] The service server ( 210 ) may also be used for contributing additional services, functions, etc., such as e.g. news, reading of mails, speech mails, commercials, music, stock exchange and financial news, etc., which may be sent to a user ( 201 ; 201 ′) of the system, e.g. depending on a user profile. [0134] A further functionality that may be provided by the server ( 210 ) is a chat-line, chat-rooms, telephone meetings, etc., where several terminals ( 200 ; 200 ′)/users ( 201 ; 201 ′) are given the opportunity of communicating with each other so that everybody can hear what everybody says. [0135] A further option might be that the user profile comprises a “negative list” of persons with whom no contact is desired. [0136] The system operates in that when e.g. a first user ( 201 ) wants to talk to a second user ( 201 ′), the first user ( 201 ) indicates this on the portable communications terminal ( 200 ). This indication may take place by keypad entering, voice command, etc. of an alias, an IP address or the like of the second user ( 201 ′). [0137] The terminal ( 200 ) establishes a connection via the wireless connection to the transceiver ( 203 ), the connecting unit ( 202 ) and the Internet ( 220 ), where e.g. the alias of the user ( 201 ′) is transmitted. The server ( 210 ) checks whether the second user ( 201 ′) with the forwarded alias is accessible/online and, if so, obtains a current IP address of the second user ( 201 ′). Then a two-way connection is established between the first user ( 201 ) and the second user ( 201 ′) via the router ( 212 ). [0138] Alternatively, the current IP address of the second user ( 201 ′) may be sent back to the first user's ( 201 ) terminal ( 200 ), thereby allowing a direct two-way connection to be established between the terminals ( 200 ) and ( 200 ′). [0139] After the connection has been established, the Internet ( 220 ) is used for transporting speech between the two users ( 201 ; 201 ′) in a suitable digital format in IP packets, as described in connection with FIG. 1 . [0140] If the terminal ( 200 ; 200 ′) and/or the service server ( 210 ) supports speech recognition, the operation of the terminal ( 200 ; 200 ′) may be simplified, and specific commands related to the service server may be passed on to the server ( 210 ) either for interpretation here or as one or more binary commands, a query or the like. [0141] Alternatively, the connecting unit ( 202 ; 202 ′) may be a mobile telephone adapted to be connected to the Internet ( 220 ) e.g. via a broadband connection equipped with e.g. Bluetooth or DECT functionality or other suitable wireless connections. Hereby, the user ( 201 ; 201 ′) is given an even greater mobility and also the economic savings of IP telephony, as the long distance traffic takes place via the Internet ( 220 ). The mobile telephone may e.g. be of the type GSM, GPRS, etc. or of another suitable type. [0142] FIG. 2 b illustrates the system according to the invention, where another type of connecting unit is shown. This figure corresponds to FIG. 2 a , but with the difference that the second user's ( 201 ′) connecting unit is now formed by a gateway ( 230 ). The gateway ( 230 ) provides coupling possibilities for several terminals ( 200 ; 200 ′)/users ( 201 ; 201 ′) e.g. in a local network, intranet, a household, a block of flats, etc. [0143] Alternatively, the gateway ( 230 ) may be provided/incorporated in a refrigerator, a television set e.g. via cable or satellite, or other household devices providing the possibility of access to the Internet. Preferably, a gateway ( 230 ) with broadband possibility is used, e.g. via ISDN, ADSL, Frame Relay, xDSL, etc. [0144] FIG. 2 c illustrates the system according to the invention where a user coupled to the traditional telephone network (PSTN) is shown. This figure corresponds to FIGS. 2 a and 2 b with the difference that the second user's ( 201 ) connecting unit is now formed by a PSTN interface/gateway ( 240 ) coupled to the user's ( 201 ′) ordinary standard telephone ( 241 ). It is hereby also possible to reach users on the traditional telephone network. [0145] FIG. 3 a illustrates a flowchart of an embodiment of the method according to the invention. [0146] In step ( 301 ), a wireless connection is established between a communications terminal, such as e.g. an ear telephone, a headset, etc. and a connecting unit, such as e.g. a computer, mobile telephone, Internet access point, PDA or the like providing the possibility of establishing a connection to the Internet or a connection to another network. [0147] In step ( 302 ), the terminal transmits information using the TCP/IP protocol to a service server, coupled to the Internet/network via the connecting unit, regarding the identity of the user (alias, etc.), regarding whether the user is online (wants to be available for calls), and regarding the physical IP address at which the terminal may be reached. This information is stored/updated in one or more databases at the server. [0148] Then, optionally in accordance with a user profile, the server can transmit data and information, such as news, reading of mails, speech mails, commercials, music, stock exchange and financial news, etc. to the user. [0149] A check is made in step ( 303 ) as to whether the user wants to contact another user. [0150] If so, a request is sent in step ( 304 ) to the server comprising e.g. an alias of the user whom it is desired to contact. The service server checks whether a user having this alias exists, whether the person concerned is online, and, if so, at which physical IP address this other user can be reached. [0151] If this is not desired, then idle mode is resumed, and the check ( 303 ) is performed currently by interrupt, polling, etc. Other functions may be carried out in idle mode. [0152] Then a connection is established in step ( 305 ) between the first and second users, following which the actual conversation can begin. The connection is preferably a TCP/IP connection either via the service server or directly. If the connection is direct a new/another TCP/IP connection has to be established between the to conversation participants and if the connection is via the server the TCP/IP connection established in step ( 301 ) may be used. [0153] In steps ( 306 )-( 308 ), the data received from the second user are handled and played, but recording of sound and transmission of it to the second user take place in steps ( 309 )-( 311 ). These steps may be performed either simultaneously/parallel or alternating e.g. by multiplexing, etc. [0154] In step ( 306 ), data are received via the wireless interface in the form of IP packets. The embedded sound data/information in the IP packets are/is converted into a first analog sound signal in step ( 307 ), e.g. by a D/A converter, codec, etc., and then it is reproduced/played for the user in step ( 308 ) e.g. via a loudspeaker, sound generator, etc. [0155] In step ( 309 ), sound is captured by a microphone, a transducer, etc. in the form of a second electrical signal, which is converted via an A/D converter, codec, etc. into a digital signal in step ( 310 ). The information of this digital signal is split and embedded in IP packets by TCP/IP protocol means which is RF modulated (e.g. the IP packets are converted/embedded in packets according to the used RF protocol by wireless/RF communications means), and then the packets are transmitted to the second conversation partner via a transceiver receiving the RF packets and extracting the IP packets and transmitting the extracted IP packets via the Internet/the network to the second conversation partner. [0156] These steps ( 306 - 308 ; 309 - 311 ) are repeated until the conversation has been terminated. [0157] After the conversation has been terminated, which is checked in step ( 312 ), the system returns to idle mode in step ( 303 ) and waits for a new call (either incoming or outgoing). [0158] The steps of receiving a call, shown in FIG. 3 b , is similar to the steps in FIG. 3 a where an incoming call is detected and the user may have the option of accepting or refusing the call. If the call is accepted a TCP/IP connection between the caller and the receiver is established either directly or via a service server and steps like ( 306 - 311 ) are performed. If a call is refused the terminal returns to idle mode. Preferably, the method comprises the steps of ( 301 - 302 ), a test ( 303 ) of whether an incoming and/or outgoing call is detected, and the steps ( 304 - 312 ) where step ( 304 ) only is executed for outgoing calls. [0159] FIG. 4 shows a preferred embodiment of a communications terminal according to the invention. An ear telephone ( 400 ) is shown in the figure. The ear telephone ( 400 ) is preferably moulded and can be manufactured individually in conformity with the user's ear. Shown is a sound generator ( 401 ), such as e.g. a loudspeaker which is used for reproducing sound information received via wireless communications means (not shovvn), as explained above. Also shown is some type of microphone, transducer or other sound capturing unit (shown in part) with a rubber coating ( 402 ) for sound capture and generation of a second electrical signal. [0160] The functionality of the ear telephone corresponds to the terminal described in connection with FIG. 1 and the system. [0161] This provides a very discrete, compact and hands-free or minimally hand-operated communications terminal of a small physical size e.g. 5-8 cm̂3. [0162] Alternatively, the wireless communications means may be arranged externally of the ear telephone ( 400 ) itself and e.g. be positioned in a housing which may be secured to the body of the user, e.g. in the belt. The housing and the ear telephone are then merely to be connected, e.g. via a wire or other wireless communications means which need a smaller range than the wireless communications means for communication with the connecting unit, and can therefore have a smaller physical size, smaller energy consumption, etc. [0163] For further details of an example of an ear telephone reference is made e.g. to the European Patent Application EP 0 673 587. [0164] FIG. 5 shows a perspective view of an alternative preferred embodiment of a communications terminal according to the invention. Shown is very compact headset ( 500 ) comprising a microphone, transducer, or other sound capturing unit ( 505 ) for capturing sound for transmission in the form of a second electrical signal, where the sound capturing unit ( 505 ) is located at one end of a brace, arm, boom, etc. ( 504 ) so that the sound capturing unit may conveniently be placed in close proximity of a user's mouth. The other end of the brace, arm, boom, etc. ( 504 ) is secured to a, preferably watertight, container, housing, etc. ( 502 ) comprising the electronic elements/parts (except audio means) described in connection with FIG. 1 . [0165] A brace, spring, arm, etc. ( 501 ) is also shown secured to the housing ( 502 ) which may be used to stabilise and secure the headset ( 500 ) to a user's head. [0166] The headset ( 500 ) also comprises an aerial, antenna, etc. (not shown) used for wireless communication and operating means ( 506 ) like one or more buttons, switches, etc. e.g. used for accepting/refusing calls. The aerial may be an intern aerial located in the housing ( 502 ). Alternatively, the brace, arm, boom, etc. ( 504 ) may constitute the aerial. [0167] Secured to the housing ( 502 ) is an earpiece ( 503 ) that may be moulded and manufactured individually in conformity with a user's ear, to be inserted into the user's ear. The earpiece comprises a sound generator, etc. for playing the received sound in the user's ear. [0168] Hereby, a very discrete, compact and hands-free or minimally hand-operated communications terminal of a small physical size is obtained.

A communication terminal for Internet telephony is provided that handles and control communication of data in accordance with a standardized network protocol and exchanges data with a connecting unit connected to the Internet where the resulting data exchanged between the terminal and a connecting unit consist of packets in a standardized protocol data packet format embedded in a wireless format. This provides a communications terminal which uses a network or the Internet for the transfer of digitized speech, etc., thereby achieving great economic savings. Also, the flexibility is increased with respect to wireless communication with the network or the Internet without any need for specialized equipment and functionality.

big_patent

This is a continuation, of application Ser. No. 07/876,930, filed May 5, 1992, now abandoned. BACKGROUND OF THE INVENTION An arrangement of layers with an oxide between a conducting layers and another conductor or semiconductor is usable as a portion of many of the structures used in semiconductor circuitry, such as capacitors, MOS transistors, pixels for light detecting arrays, and electrooptic applications. High-dielectric oxide materials provide several advantages (e.g. ferroelectric properties and/or size reduction of capacitors). Pb/Bi-containing high-dielectric materials are convenient because of their relative low annealing temperatures and, as they retain desirable properties in the small grains preferred in thin films. The integration of non-SiO 2 based oxides directly or indirectly on Si is difficult because of the strong reactivity of Si with oxygen. The deposition of non-SiO 2 oxides have generally resulted in the formation of a SiO 2 or silicate layer at the Si//oxide interface. This layer is genre ally amorphous and has a low dielectric constant. These properties degrade the usefulness of non-SiO 2 based oxides with Si. High-dielectric constant oxide (e.g. a ferroelectric oxide) can have a large dielectric constant, a large spontaneous polarization, and a large electrooptic properties. Ferroelectrics with a large dielectric constant can be used to form high density capacitors but can not deposited directly on Si because of the reaction of Si to form a low dielectric constant layer. Such capacitor dielectrics have been deposited on "inert" metals such as Pt, but even Pt or Pd must be separated from the Si with one or more conductive buffer layers. Putting the high dielectric material on a conductive layer (which is either directly on the semiconductor or on an insulating layer which is on the semiconductor) has not solved the problem. Of the conductor or semiconductor materials previously suggested for use next to high dielectric materials in semiconductor circuitry, none of these materials provides for the epitaxial growth of high dielectrical materials on a conductor or semiconductor. Further, the prior art materials generally either form a silicide which allows the diffusion of silicon into the high dielectric materials, or react with silicon or react with the high dielectric oxide to form low dielectric constant insulators. The large spontaneous polarization of ferroelectrics when integrated directly on a semiconductor can also be used to form a non-volatile, non-destructive readout, field effect memory. This has been successfully done with non-oxide ferroelectrics such as (Ba,Mg)F 2 but much less successfully done with oxide ferroelectrics because the formation of the low dielectric constant SiO 2 layer acts to reduce the field within the oxide. The oxide can also either poison the Si device or create so many interface traps that the device will not operate properly. Ferroelectrics also have interesting electrooptic applications where epitaxial films are preferred in order to reduce loss due to scattering from grain boundaries and to align the oxide in order to maximize its anisotropic properties. The epitaxial growth on Si or GaAs substrates has previously been accomplished by first growing a very stable oxide or fluoride on the Si or GaAs as a buffer layer prior to growing another type of oxide. The integration of oxides on GaAs is even harder than Si because the GaAs is unstable in O 2 at the normal growth temperatures 450 C.-700 C. SUMMARY OF THE INVENTION While Pb/Bi-containing high-dielectric materials are convenient because of their relative low annealing temperatures and their desirable properties in the small grains, Pb and Bi are very reactive and have been observed to diffuse into and through metals such as Pd or Pt. A Ge buffer layer on Si oxidizes much less readily and can be used to prevent or minimize the formation of the low dielectric constant layer. An epitaxial Ge layer on Si provides a good buffer layer which is compatible with Si and also many oxides. Unlike other buffer layers, Ge is a semiconductor (it can also be doped to provide a reasonably highly conductive layer) and is compatible with Si process technology. The epitaxial growth of Ge on top of the ferroelectric or high-dielectric constant oxide is also much easier than Si which makes it possible to form three dimensional epitaxial structures. The Ge buffer layer can be epitaxially gown on the Si substrate allowing the high dielectric constant oxide to be epitaxially gown on the Ge and hence epitaxially aligned to the Si substrate. The epitaxial Ge layer allows ferroelectrics to be directly gown on Si wafers to form non-volatile non-destructive read out memory cells. The Ge buffer layer will also increase the capacitance of large dielectric constant oxide films compared to films gown directly on Si. A Ge buffer layer on the Si or GaAs substrate allows many more oxides to be epitaxially gown on it because of the much smaller chemical reactivity of Ge with oxygen compared to Si or GaAs with oxygen. However, not all oxides are stable next to Ge. For example, all ferroelectrics containing Pb such as Pb(Ti,Zr)O 3 (PZT) are not thermodynamically stable next to Ge (since PbO is not stable). A thin layer of SrTiO 3 or other stable ferroelectric can, however, be used as a buffer layer between the Pb containing ferroelectric and the Ge coated Si substrate. The SrTiO 3 not only acts as a chemical barrier, but also nucleates the desired perovskite structure (instead of the undesirable pyrochlore structure). As noted, the integration of oxides on GaAs is even harder than Si because the GaAs is unstable in O 2 at the normal growth temperatures of high-dielectric constant oxide (450 C.-700 C.). An epitaxial Ge and non-Pb/Bi-containing high-dielectric material buffer layers solves this problem and simplifies the integration of Pb/Bi-containing ferroelectrics on GaAs for the same applications as listed above. This is a method for fabricating a structure useful in semiconductor circuitry. The method comprises: growing a buffer layer of non-Pb/Bi-containing high-dielectric constant oxide layer directly or indirectly on a semiconductor substrate; and depositing a Pb/Bi-containing high-dielectric constant oxide on the buffer layer. Preferably a germanium layer is epitaxially gown on the semiconductor substrate and the buffer layer is grown on the germanium layer. The non-Pb/Bi-containing high-dielectric constant oxide layer is preferably less than about 10 nm thick. A second non-Pb/Bi-containing high-dielectric constant oxide layer may be grown on top of the Pb/Bi-containing high-dielectric constant oxide and a conducting layer may also be grown on the second non-Pb/Bi-containing high-dielectric constant oxide layer. Preferably both the high-dielectric constant oxides are ferroelectric oxides and/or titanates, the non-Pb/Bi-containing high-dielectric constant oxide is barium strontium titanate, and the Pb/Bi-containing high-dielectric constant oxide is lead zirconate titanate. Both the non-Pb/Bi-containing high-dielectric constant oxide and the Pb/Bi-containing high-dielectric constant oxide may be epitaxially grown. Alternately this may be a structure useful in semiconductor circuitry, comprising: a buffer layer of non-Pb/Bi-containing high-dielectric constant oxide layer directly or indirectly on a semiconductor substrate; and a Pb/Bi-containing high-dielectric constant oxide on the buffer layer. When the substrate is silicon, a germanium layer, preferably less than about 1 nm thick is preferably used on the silicon. Both the non-Pb/Bi-containing high-dielectric constant oxide and the Pb/Bi-containing high-dielectric constant oxide may be single-crystal. A second non-Pb/Bi-containing high-dielectric constant oxide layer may be used on top of the Pb/Bi-containing high-dielectric constant oxide. BRIEF DESCRIPTION OF THE DRAWINGS Further features of the present invention will become apparent from a description of the fabrication process and structure thereof, taken in conjunction with the accompanying drawings, in which: FIG. 1 shows a cross-section of one embodiment of a multi-layer structure using a BST buffer layer, FIG. 2 shows a cross-section of an alternate embodiment of a multi-layer structure using a BaZrO3 (BZ) buffer layer; and FIG. 3 shows a cross-section of an embodiment of a multi-layer structure using a second buffer layer and a top electrode. DETAILED DESCRIPTION OF THE INVENTION As noted, Pb/Bi-containing high-dielectric materials are convenient but Pb and Bi are very reactive and diffuse into and through even noble metals and growth of oxides on Si generally results in the oxidation of the Si and the formation of SiO 2 or a silicate layer. Further, this SiO 2 layer prevents the epitaxy of the deposited oxide and has a low dielectric constant and the integration of ferroelectrics and other large dielectric constant materials directly on Si is degraded by the formation of the low dielectric constant SiO 2 layer (on metal). Also as noted, putting the high dielectric material on a metallic layer (which is either directly on the semiconductor or on an insulating layer which is on the semiconductor) has not solved the problem with PbBi diffusion. The diffusion of lead or bismuth from ferroelectrics such as Pb(Ti,Zr)O (PZT) into an adjacent metal can, however, be controlled by a thin layer of SrTiO 3 or other stable high-dielectric oxide used as a buffer layer between the Pb/Bi containing ferroelectric and the metallic layer or the Si substrate. Preferably a Ge buffer layer is used between high-dielectric oxides and Si or metal reduces the reactivity at the surface and in general enhances the epitaxy and at least reduces the reaction layer between the deposited oxide and the substrate. The epitaxial growth of Ge on Si is compatible with current Si process technology. The main difficulty with Ge on Si is the 4% lattice mismatch which results in misfit dislocation on Ge films thicker than 1 nm. On silicon, the Ge layer is preferably very thin to avoid the misfit dislocations (however a thicker layer may be used for some devices if that is not detrimental to the performance of the device in question). In still other embodiments, polycrystalline Ge may be formed over polycrystalline Si (thus using the Ge as a chemical buffer layer between a deposited oxide and the Si substrate). Depending on the application the choice of materials may be very different. For large density capacitors, currently the best linear dielectric appears to be (Ba 1-x ,Sr x )TiO 3 (BST). BaTiO 3 (BT) or SrTiO 3 (ST) when deposited directly on Si forms a low dielectric constant layer, and thus BT and ST are not thermodynamically stable next to Si. Ge, however, has a much smaller free energy of oxidation and BT and ST are thermodynamically stable next to Ge. It is also possible to deposit BT and ST in a H 2 +O 2 gas mixture such that Ge is stable and also BT or ST is stable while GeO 2 is not stable. As noted above, not all oxides are stable next to Ge. For example, all ferroelectrics containing Pb such as Pb(Ti,Zr)O (PZT) are much less stable next to Ge (since PbO is not stable). A thin layer of SrTiO 3 or other stable ferroelectric can, however, be used as a buffer layer between the Pb containing ferroelectric and the Ge coated Si substrate. The SrTiO 3 not only acts as a chemical barrier, but also nucleates the desired perovskite structure (instead of the undesirable pyrochlore structure). There has been little investigation of the use of a second ferroelectric layer as a chemical buffer layer. Others have deposited a thin layer of PbTiO 3 , or (Pb,La)TiO 3 prior to the deposition of PZT in order to help nucleate the perovskite structure and avoid the formation of pyrochlore, but apparently have not used the depositing of a stable ferroelectric buffer layer to act as a diffusion barrier. SrTiO 3 (ST0) or BaTiO 3 (BT), for example, can be used as a buffer layer between Pt and PZT. The ST or BT improve the properties for several reasons. The first is that Pb is very reactive and it has been observed to diffuse into and through Pt. ST or BT is much less reactive and forms a good diffusion barrier to Pb. Because ST has the same perovskite structure, the Pb will slowly react with the ST and form (Pb,Sr)TiO 3 . This reaction is believed to be by bulk diffusion which is fairly slow. The ST will also act as a nucleation layer for the perovskite structure of PZT. ST also has a very low leakage current and a thin layer tends to improve the leakage properties of the PZT. Such a buffer layer needs to be structurally compatible with the ferroelectric (perovskite structure for PZT), and chemically compatible with both layers. Materials like BaZrO 3 (BZ) satisfy these requirements for PZT. In addition, the buffer layer must not significantly degrade the electrical properties. ST, BST, and BT have large dielectric constants which helps share the electric field and hence are preferred to materials with a somewhat lower dielectric constant (like BZ). What matters is the properties after the deposition of the second (lead-containing) ferroelectric layer. This deposition can change the properties of the buffer layer. It is also important to avoid problems between the non-lead-containing high-dielectric material and the substrate. An epitaxial Ge buffer layer was used in experiments on a (100) Si substrate to deposit epitaxial BST. Without the Ge buffer layer, the BST was randomly oriented polycrystalline. With the Ge buffer layer, most of the BST has the following orientation relationship (110) BST∥(100) Si. This showed that the Ge buffer layer has prevented the formation of a low dielectric layer at the interface prior to epitaxy since that layer would prevent epitaxy. The deposition of a ferroelectric directly on a semiconductor has been used by others to create a non-volatile nondestructive readout memory. This device is basically a MOS transistor where the SiO 2 has been replaced with a ferroelectric (metal-ferroelectric-semiconductor or MFS). One memory cell consists of a MFS transistor and a standard MOS transistor. This type of memory has many advantages including very fast read/write as well having nearly the same density as a standard DRAM cell. The remnant polarization in the ferroelectric can be used induce a field into the semiconductor and hence the device is non-volatile and non-destructive. This device has been successfully made by others using a (Ba,Mg)F 2 ferroelectric layer epitaxially grown by MBE on the Si substrate. Oxide perovskites such as PZT have also been studied for non-volatile memories but these materials can not be deposited directly on Si without reacting with the Si. A Ge buffer layer will allow many stable ferroelectrics, such as BaTiO 3 , to be used in a RAM. A second buffer layer of SrTiO 3 or some other stable ferroelectric should allow even most chemically reactive ferroelectric oxides to be used to try to form a RAM. The Ge buffer layer would also allow this type of memory to be fabricated on GaAs and other III-V compounds in addition to Si. It also might be possible to fabricate a thin-film MFS transistor by depositing the Ge on top of the ferroelectric. The ferroelectric might be epitaxial on the GaAs or Si substrate or it might be polycrystalline. The compatibility of Ge with a stable ferroelectric buffer layer allows this structure to be manufactured, including with a lead-containing high-dielectric material. In FIG. 1 there is shown one preferred embodiment (in all figures, an arrangement of layers is shown which is usable as a portion of many structures used in semiconductor circuitry, such as capacitors, MOS transistors, pixels for light detecting arrays, and electrooptic applications. FIG. 1 shows a semiconductor substrate 10, on which a doped polycrystalline germanium layer 12 has been deposited (the germanium can be highly doped to provide a highly conductive layer). The germanium can be polycrystalline or single-crystal. A ferroelectric barium strontium titanate layer 14 (which also can be polycrystalline or single-crystal) is deposited on the germanium layer, and a lead zirconium titanate layer 16 is deposited atop the barium strontium titanate 14. As noted, such an arrangement of layers is usable in many semiconductor structures and the ferroelectric or high dielectric properties of a non-lead-containing buffer layer such as barium strontium titanate provides advantageous properties over most other insulating materials. While optimum properties of non-lead-containing high dielectric materials are not generally obtained without a relatively high temperature anneal and are not generally obtained in submicron sized gains, the fine gained material without a high temperature anneal, still has material properties substantially superior to alternate materials. Thus while barium strontium titanate with a high temperature anneal and with gain size of 2 microns or more, generally has a dielectric constant of greater than 10,000, a fine gained low temperature annealed barium strontium titanate might have a dielectric constant of 200-500. Thus, when used as a buffer layer for lead zirconium titanate (with a similar gain size and firing temperature, might have a dielectric constant of 800-1,000), such that the composite film dielectric constant lowered only slightly from the dielectric constant of the lead zirconium titanate. Thus, a composite dielectric is provided which provides good dielectric constants with fine grained and relatively low fired material. FIG. 2 shows an alternate embodiment, utilizing a gallium arsenide substrate 18 with a platinum-titanium-gold layer 20 and a BaZrO 3 buffer layer 22 (again note that such a barium zirconate layer provides a somewhat lower dielectric constant, but this is less of a problem in very thin layers). In FIG. 2, the top layer is (Pb,La)TiO 3 . While, top electrodes can be applied directly over the lead-containing high dielectric material, (as lead migration into the top electrode does not cause the very serious problems caused by lead diffusing into a semiconductor substrate), a top buffer layer is preferred between the lead containing high dielectric material and the top electrode. FIG. 3 illustrates such an arrangement. A germanium layer 12 is utilized on top of the silicon substrate 10, with a SrHfTiO 3 layer 26 on top of the germanium layer 12. A Bi 4 Ti 3 O 12 layer 28 is on the SrHfTiO 3 layer 26 and a top buffer layer of BaSrTiO 3 30 is on top of the Bi 4 Ti 3 O 12 28. A titanium tungsten top electrode 32 is then deposited atop the second buffer layer 26. To provide a structure which is even more stable, a second germanium layer (not shown) could be inserted between the BaSrTiO 3 30 and the titanium tungsten top electrode 32. The use of a second germanium layer allows the usage of a wider variety of conductors for the top electrode and allows higher temperature processing during and after the deposition of the top electrode, as the germanium generally prevents reaction between the top electrode material and the ferroelectric material. While a number of materials have been previously been suggested for use next to high dielectric materials (such as barium strontium titanate or lead zirconium titanate), none of these materials provides for the epitaxial growth of high dielectrical materials on a conductor or semiconductor. Further, the prior art materials generally either form a silicide (e.g. of palladium, platinum or titanium) which allows the diffusion of silicon into the high dielectric materials, or react with silicon (e.g. tin dioxide) or react with the high dielectric oxide to form low dielectric constant insulators (e.g. titanium monoxide or tantalum pentoxide). Thus the prior art conductive materials suggested for interfacing with high dielectric constant oxides with semiconductors either have reacted with the high dielectric constant oxides or with the semiconductor and/or metal have not provided a diffusion barrier between the high dielectric constant oxides and semiconductor material. At the annealing temperatures necessary to produce good quality high dielectric constant oxide material, such reactions generally form low dielectric constant insulators, which being in series with the high dielectric constant oxide material, dramatically lowers the effective dielectric constant. Only germanium (doped or undoped) gives a conductor or semiconductor which reacts neither with the semiconductor substrate nor the high dielectric constant oxide at the required annealing temperatures, and only germanium provides for epitaxial growth of a conductive or semiconductive material on a semiconductor substrate, in a matter compatible with growing and annealing of a high dielectric constant oxide in a non-reactive manner, such that a metal oxide metal or metal oxide semiconductor structure can be fabricated without the effective dielectric constant being significantly lowered by a low dielectric constant material between the high dielectric constant material and the underlying conductor or semiconductor. Even using germanium, however, does not completely eliminate problems with the Pb/Bi diffusion, and thus a non-Pb/Bi high-dielectric oxide containing buffer layer is still needed. Since various modifications of the semiconductor (e.g. silicon or gallium arsenide) structure, and the methods of fabrication thereof, are undoubtedly possible by those skilled in the art without departing from the scope of the invention, the detailed description is thus to be considered illustrative and not restrictive of the invention as claimed hereinbelow. For example, much of the discussion has generally used the term "ferroelectric" materials, however, the invention is generally applicable to any "high-dielectric constant oxide" and, while many are ferroelectric titanates, some such materials are not ferroelectric and some not titanates. The term "high-dielectric constant oxides" as used herein is to mean oxides with dielectric constants of greater than 100, and preferably greater than 1,000 (barium strontium titanate can have dielectric constants greater than 10,000). Many such non-Pb/Bi oxides can be considered to be based on BaTiO 3 and includes oxides of the general formula (Ba,Sr,Ca)(Ti,Zr,Hf)O 3 . Many other oxides of the general formula (K,Na,Li)(Ta,Nb)O 3 will also work. Pb/Bi oxides, for the purpose of this invention, generally include perovskites whose component oxides are thermodynamically unstable next to germanium metal and non-Pb/Bi high-dielectric oxides for these purposes generally include perovskites whose component oxides are thermodynamically stable next to germanium metal (even if a germanium layer is not used). Pb/Bi oxides include materials such as (Pb,La)ZrTiO 3 or (Pb,Mg)NbO 3 or Bi 4 Ti 3 O 12 . All these oxides can also be doped with acceptors such as Al, Mg, Mn, or Na, or donors such as La, Nb, or P. Other semiconductors can also be used in addition to silicon and gallium arsenide.

This is a method for fabricating a structure useful in semiconductor circuitry. The method comprises: growing a buffer layer of non-Pb/Bi-containing high-dielectric constant oxide layer directly or indirectly on a semiconductor substrate; and depositing a Pb/Bi-containing high-dielectric constant oxide on the buffer layer. Alternately this may be a structure useful in semiconductor circuitry, comprising: a buffer layer 26 of non-lead-containing high-dielectric constant oxide layer directly or indirectly on a semiconductor substrate 10; and a lead-containing high-dielectric constant oxide 28 on the buffer layer. Preferably a germanium layer 12 is epitaxially grown on the semiconductor substrate and the buffer layer is grown on the germanium layer. When the substrate is silicon, the non-Pb/Bi-containing high-dielectric constant oxide layer is preferably less than about 10 nm thick. A second non-Pb/Bi-containing high-dielectric constant oxide layer 30 may be grown on top of the Pb/Bi-containing high-dielectric constant oxide and a conducting layer (top electrode 32) may also be grown on the second non-Pb/Bi-containing high-dielectric constant oxide layer.

big_patent

BACKGROUND OF THE INVENTION Receiver input circuits comprising a preamplifier arrangement followed by a mixer arrangement which are connected to one another by adjustable selection means and whose total amplification is controlled and regulated in dependence upon signal input are used, for example, in input circuits for radio and television receivers. With these circuits, it is a question of arriving at a favorable compromise between small and large signal behavior, on the one hand, and low production cost, on the other hand. In the known circuits, this problem is mainly dealt with by appropriate selection of the active semiconductor components and by amplification control. This problem is caused by the limited dynamic characteristics of the passive and active semiconductor components such as bipolar transistors, field-effect transistors and diodes, including tuning diodes. The Siemens publication "Semiconductor Circuitry Examples" 1972/73, pages 38 to 43, describes circuitry examples for TV tuners dealing with the above-mentioned problem. The block wiring diagram on page 39 of this publication shows, for example, the set-up of a VHF/UHF input section for a TV receiver with an input high-pass filter, followed by a PIN control network, antenna filter for VHF and UHF input sections, uncontrolled preamplifier stages for VHF and UHF and also, for example, band filters tuned with varactor diodes between preamplifier and following mixer stage. Amplification control is effected from a higher input signal level via the PIN diode control network, with the control signal being taken from the IF section of the receiver. This type of amplification control serves to protect the semiconductor components, in this case, bipolar transistors and varactor diodes, from stronger signal drives causing distortions. The basic advantage of such amplification control with PIN diodes lies in the fact that the PIN diodes of the control network themselves cause practically no distortions at all. In the known circuit, however, the noise level increases to the same extent as the control attenuation, causing control actuation to be moved to as high as possible signal levels in order to reach a sufficiently high S/N ratio level with stronger signals at all. In the known circuit, the preamplifier transistor itself is used for amplification control. Here, amplification is lowered by upward control of the collector current of this transistor. The disadvantage of such amplification control is, however, that it entails a non-linearity, dependent on the control condition and partly quite strong, which, in turn, causes signal distortions, inter alia, cross modulation and intermodulation. Another Siemens publication "Semiconductor Circuitry Examples" 1973/74, page 34, describes a circuit arrangement for the input section of an FM radio receiver with electronically tunable selective circuits. Here, too, amplification control is effected by means of a PIN diode control network between antenna input and the first selective circuit. In this example, the control signal is taken from the IF signal at the output of the circuit, in which case it is recommended to set the control so as to engage only from approximately 1 mV usable signal in order to obtain the maximum S/N ratio level. This type of control serves to prevent overloading of the circuit due to negative outside influences. In the known circuit, the control signal is obtained, relative to the transmission band width, in a narrow band from the signal input to the mixer. This involves the danger of overloading the preliminary and mixer stages with strong signals to which the circuit is not tuned. The mixer stage is particularly endangered here if no or only insufficient amplification step-down control is possible because of the narrow band in which the control signal is gained, and if one or several strong signals reach the mixer stage, amplified or hardly attenuated because of large HF band width and corresponding low selectivity. However, the varactor diodes used in electronic tuning also cause negative influences if they are subjected to strong signals. They themselves then cause cross modulation and intermodulation, for example, and, at certain signal levels and frequencies, can even occasion relaxation oscillations, combined with a strong modulation of the usable signals. This effect is caused by the dynamic change in the average capacity of the varactor diodes with increasing applied signal voltage. The varactor diodes at the output of the preamplifier stage are affected most, if, as explained above, the preamplifier stage has not or only insufficiently been subjected to step-down control. Even if no relaxation oscillations appear, mistuning of the preselection circuits may occur in the case of a received weak usable signal due to the dynamic capacity changes in the varactor diodes, weakening the usable signal reaching the mixer and thus deteriorating the S/N ratio of the usable signal received. This preselection problem with varactor diodes as tuning reactances is aggravated if it is attempted, under otherwise approximately identical conditions, to obtain a high level of preselection, i.e., trimming the preselection circuits to a high level of resonance quality, a measure which, for instance, appears desirable in view of the large signal characteristics caused by the mixer stage. Such a measure would, on the other hand, intensify possible interference effects, for with identical signal power, a greater signal voltage occurs at the varactor diodes owing to the higher resonance quality. SUMMARY OF THE INVENTION It is an object of the invention to provide a receiver input circuit which enables substantial elimination of an undesired signal actuation of the non-linear components in the signal path resulting in distortions, taking into account an adequate small signal behavior and using conventional components. According to the invention, there is provided in a receiver input circuit comprising a control loop for amplification control, with the control signal for the control loop being derived from the intermediate frequency signal and supplied to the part of the circuit preceding the mixer stage, in addition to a second amplification control loop whose control signal is taken out prior to the mixer stage, a third amplification control loop whose response threshold and frequency band width are lower than the response threshold and frequency band width of the first and second control circuits. BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described in greater detail, by way of example, with reference to the drawings, in which: FIG. 1 shows the principle underlying the invention, with several amplification control circuits; FIG. 2 is an embodiment of a receiver input circuit; FIG. 3 is an embodiment with an extended, permanently tuned input network; FIG. 4 is an embodiment with an extended, tunable input network; FIG. 5 is an embodiment for the iteration-free alignment of the tuned circuits; FIG. 6 is an embodiment for the common tuning of a two-circuit filter with a twin varactor diode. DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 shows the principle underlying a receiver input circuit 1 according to the invention with the usual functional parts such as preamplifier 4, tunable selective network 5, mixer and oscillator stage 6 and intermediate frequency selective filter 7, from which the preselected intermediate frequency signal is taken and then fed to the intermediate frequency section 13 of the receiver. The use of several amplification control circuits according to the invention is shown in FIG. 1, i.e., two control circuits within the input circuit 1 and an outer control circuit which includes the intermediate frequency amplifier 13. The control signal for the first control circuit is obtained at the output of the preamplifier stage (control signal line 11), for the second control circuit at the output of the mixer stage (control signal line 12), and for the third control circuit in the signal frequency selective intermediate frequency amplifier 13. Amplification is controlled jointly in the input network 3 by means of the control signal 15 processed in the control signal processing circuit 10. The high frequency signal voltages are converted into direct signals for the first and second control circuit in the rectifier circuits 9 and 8, respectively. The positive effect of the circuit according to the invention is already obtained from the use of the first and second control loop. These fulfill the following tasks and they are arranged as follows: (a) first amplification control circuit Avoidance of unwanted overloading of the mixer stage and/or the varactor diodes which may be used in the tunable network 5, if the second control circuit is inactive. The effective band width is approximately identical with the transmission band width of the network 5 (HF selective filter) and the signal response threshold for control application is below the modulation limit for the mixer input or--if applicable--the varactor diodes of the selective filter 5. The maximum response threshold is determined by the fact that no relaxation oscillations or control oscillations occur in the given frequency and level range, even if its amplitude is modulated. (b) second amplification control circuit Avoidance of overloading of the mixer stage (also on the output side) as well as frequency influences acting upon the oscillator because of powerful usable signals to which the receiver is tuned, or by means of spurious signals in close proximity to the frequency. The effective band width is less than that of the first control circuit but greater than that of the third control circuit and it corresponds approximately to the selective characteristics of the intermediate frequency filter 7. The signal response threshold is set lower than that of the first control circuit. In a first further embodiment of the invention, the third amplification control circuit can be used to support the other control circuits, in which case the effective band width and the signal response threshold are lower than for the second control circuit. In a second further embodiment of the invention, the response threshold of the third control circuit may be controlled by the control signal, preferably of the second control circuit, in such a way that the signal response threshold is reduced by it from a certain spurious signal level on. This enables the amplification of the circuit to be lowered even in the case of a small usable signal, thus affording better protection of the input circuit from the negative influences of stronger spurious signals, which is expedient and harmless if the signal noise ratio of the usable signal received were impaired by stronger spurious signals anyhow, caused, e.g., by the phase noise of the input oscillator. An embodiment of the input circuit according to the invention is shown in FIG. 2. This includes the input network 3 with the three reactance elements (3a, 3b, 3c) and a PIN diode 3d for controllable signal attenuation, the preamplifier stage 4 with a bipolar transistor 4b in grounded-base circuits 16 and 17, the mixer and oscillator stage 6, the intermediate frequency filter 7 with the resonant circuit 18, the rectifier circuits 8 and 9 and the control signal processing circuit 10. The signal-dependent direct signals obtained in the rectifier circuits 8 and 9 are smoothed by a capacitor 21 and directed to a controlled shunt resistor in the circuit section 10 as a control signal. The shunt resistor located between the circuit point 4h and reference potential controls the direct current flowing to the PIN diode 3d, with the sum of the currents through the shunt resistor and through the PIN diode 3d being identical to the operating current of the preamplifier stage 4. Control of the PIN diode (amplification control member) is thus effected by the distribution of the operating current determined by the shunt resistor to the PIN diode and the shunt resistor. This type of amplification control has the advantage that the operating current of the total circuit hardly changes at all during amplification control and that there is no substantial additional control power requirement. A further advantage of this type of amplification control with the almost constant operating power during control lies in that in the case of integration of the control circuit with other circuit sections there are no substantial temperature changes in the integrated circuit during the control procedure. The advantage of PIN diode control in the input network 3 in front of the first distortion-forming member (4b) is that all distortion-forming circuit components can be protected against signal overloading during control. The control circuit according to the invention based on a PIN diode also has the advantage that the following amplifier component is protected against high-voltage discharge surges from the antenna. Since rectifier circuits are generally the source of signal distortions themselves (e.g. intermodulation) it is expedient to arrange rectifier circuits 8 and/or 9 in such a way that the signal distortions which may occur do not affect the input circuit. This may be achieved, for example, by means of a buffer amplifier or amplifier component which is arranged between the signal voltage to be rectified and the rectifier circuit causing the distortions. In several applications it is expedient to effect the levelling of the control signal by the capacitor 21 in such a manner that the capacitor 21 quickly charges itself up to the amount corresponding to the highest value of the signal level and follows the decreasing signal level relatively slowly. This enables greater elimination of interference through the control circuit if powerful amplitude-modulated spurious signals are present and there is danger of overloading due to peak amplitudes, and this danger cannot be avoided by a control circuit which only reacts to the arithmetical mean value. In a further development of the input network according to FIG. 3, the use of a second PIN diode 3e and an extended reactance network with the additional reactances 3f to 3k is illustrated. Here the PIN diodes act in series with respect to direct current and attenuate, on the one hand, the series-resonance of the reactance combination 3a, 3b with increasing control current flow, and, on the other hand, the parallel resonance of the parallel-resonant circuit formed by the reactances 3f and 3g. The series and parallel-resonant frequency, respectively, of the reactance combinations mentioned are identical to the center frequency of the signal frequency band to be transmitted. The capacitors 3h and 4f act practically as short circuits for the signal frequency. With the reactance 3j in the given example, a stepdown transformation of the signal source resistance connected to contact 2 to the amplifier component 4b (contact 4a) is obtained. The advantage of this input network in comparison to the one shown in FIG. 2 lies in the greater obtainable control range as well as the greater selectivity of the input circuit compared to the adjacent signal frequency bands. FIG. 4 shows a further development of the input network. Compared to the network of FIG. 1, there is a tunable selective circuit with elements 3e to 3n connected between the terminal 2 and the signal input terminal 2a. This circuit has the advantage of higher selectivity while simultaneously avoiding strong attenuation of the tunable selective circuit during control. The desired source impedance for actuation of the preamplifier transistor in the uncontrolled condition is adjusted, for example, by selection of the tapping of reactance 3e or by a correspondingly dimensioned coupling coil. All input network circuits according to FIGS. 2 to 4 have in common the fact that during control (signal attenuation at the input) the source impedance for the preamplifier transistor 4b operating in grounded-base circuit increases. The control effect is thus amplified by means of the simultaneously increasing negative current feedback without a substantial increase of the noise level during control. This is achieved by the PIN diode, whose resistance is controlled, acting at the connecting point of the reactances 3a and 3b. FIG. 5 shows the tunable network in an embodiment of the invention in which the network 5, tunable by means of varactor diodes, with the resonant circuits 16 and 17 and the oscillator circuit, has a separate supply and adjustment of the tuning voltage for the varactor diodes. This circuit permits an iteration-free alignment of all tunable tuning circuits of the receiver input circuit. The circuit operates as follows: The manipulated variable generated by the tuning voltage generator 28 (e.g. a PLL circuit) is aligned to the minimum given tuning voltage 27 at minimum given tuning frequency by means of the oscillator circuit coil. Following this, coils 16c and 17c are aligned to maximum amplification of the receiver input section at minimum signal frequency (L alignment). At the upper tuning frequency and signal frequency of the transmitting band this is followed by the so-called C alignment by means of the potentiometers 23, 24 and 25 in the following sequence: 25 (adjusting the upper tuning voltage) and 23 and 24 (maximum amplification). In an embodiment of the invention, one of the voltage dividers for the alignment may also be fixed voltage divider such as the divider 25 for the oscillator circuit, for example. The C alignment of the resonant circuits 16 and 17 with respect to one another is required if the varactor diodes do not possess a sufficiently identical C (U) characteristic. This is also true in the event that individual diodes are used instead of the twin diodes indicated in FIG. 5. FIG. 6 shows an embodiment of the tunable network 5 with one single twin diode which forms the resonant circuit 16 and 17, respectively, with the inductance 16c and 17c, respectively, and which is supplied by a single common tuning voltage. Coupling the resonant circuits is carried out inductively in this case, with the capacitor 29 constituting in the main an HF short circuit. The advantage of this embodiment of the tunable network consists in the fact that a high degree of identity of the C (U) characteristic of the varactor diodes can be expected. In this case, separate adjustment of the tuning voltage is not necessary.

A receiver input circuit comprising a control loop for amplification control, wherein the control signal for the control loop is derived from the intermediate frequency signal and supplied to the part of the circuit preceding the mixer stage. The receiver input circuit furthermore comprises a second amplification control loop whose control signal is taken out prior to the mixer stage, and a third amplification control loop whose response threshold and frequency band width are lower than the response threshold and frequency band width of the first and second control circuits.

big_patent

FIELD OF THE INVENTION This invention relates in general to network implemented shared workspace environments, and more specifically to an apparatus and method for spontaneously setting up, between physically distant individuals, a collaborative work-sharing environment. BACKGROUND OF THE INVENTION Well known examples of collaborative work-share environments include video conferencing; document sharing (read only or write access); and shared “whiteboard” systems. The majority of videoconference meetings are currently implemented using expensive, dedicated equipment such as manufactured by PictureTel™. Typically, such equipment provides not only video conferencing, but also other virtual co-location tools. Because of its cost and size, this equipment is typically located in a dedicated “videoconference room”, rather than at individual users' desktops. Such systems are used, primarily, as a means of reducing operating costs, such as air travel for the purpose of conducting face-to-face meetings. Recently, much more economical, PC-based products have been introduced to the market. Examples of current products that can be used to create a shared working environment include Intel Corporation's ProShare™ and Microsoft Corporation's NetMeeting™. These PC-based products are relatively low cost (in some cases free of charge) and are sufficiently small as to enable mass deployment on every networked PC of an enterprise LAN. Unlike dedicated conference room equipment, PC-based products can be viewed as workplace enhancements, providing added value to personal communications, rather than as tools for corporate cost reduction. In spite of the cost and space advantages of PC-based systems over prior art dedicated conferencing facilities, the PC-based products are difficult to use, especially for the majority of users who have no technical background or training. Setting up a collaborative session using existing PC-based technology typically involves cumbersome setup processes, including establishing IP-addresses, launching software etc., and are often scheduled for a date and time subsequent to the telephone discussion in which the parties agree to conduct the video conference. Furthermore, during the actual setup process, no intrinsic voice communications path exists between the parties involved. Voice communication can not take place until the setup process is complete. Using current technology, it is not uncommon for the parties to make a regular phone call in order to talk through the setup process. SUMMARY OF THE INVENTION According to the present invention, a system is provided for initiating a collaborative work-share environment between two or more parties to a telephone call, without complex and time consuming setup processes as are common in the prior art. In accordance with the preferred embodiment, each party to a telephone call is provided with a collaboration button and an indicator on their telephone set. When the indicator is illuminated, the system is capable of establishing a work-share environment. In response to one of the parties activating the collaboration button, the system causes network enabled applications to run on the individual users' desktop computers so that the parties are able to share information between themselves, conduct a video conference, etc., while maintaining their initial voice connection. Thus, the telephone is used in the usual way to make regular, voice-only, telephone calls. Once a call is established, the telephones communicate with each other to determine if they each are associated with equipment which would allow richer collaboration between their respective users. If such equipment is available then the indicator on at least one of the telephones is lit, indicating that richer collaboration is possible. If the talking parties decide that they would like to share a document or set up a video conference, this may be initiated by either party pushing the collaboration button. Once the button has been pushed, one of a number of subsequent scenarios are possible. In all cases, from a user perspective, the voice path is unaffected and the talking parties may continue uninterrupted conversation. Some implementation examples are set forth below, without limitation to the scope of the invention. In its broadest aspects, the present invention is a method and apparatus for simple spontaneous setup of a shared workspace. BRIEF DESCRIPTION OF THE DRAWINGS A preferred embodiment of the present invention is described herein below with reference to the drawings in which: FIG. 1 is a diagram illustrating a preferred station arrangement including a telephone and a desktop PC, both of which are connected to a LAN; FIG. 2 shows the overall architecture of the system according to the preferred embodiment; FIG. 3 is a flowchart showing steps in a call setup according to the method of the present invention; FIG. 4 is a flowchart showing steps for indicating at a telephone set availability of network collaboration between multiple parties following call setup; FIG. 5 is a flowchart showing steps for ceasing the indication of network collaboration availability when the call between multiple parties is being torn down; FIG. 6 is a flowchart showing steps for implementing network collaboration between multiple parties according to the invention; and FIG. 7 shows a generalized architecture of the system according to the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1 , the preferred station arrangement comprises a telephone 1 and a PC 3 , both of which are connected to a LAN 5 (Local Area Network). The telephone 1 is a component of an IP (Internet Protocol) based PBX system. In such a system, telephones, PBX hardware components, PCs and other data systems are interconnected via the LAN 5 . Critical user interface characteristics of the telephone 1 include a collaborate indicator 7 , which can be in the form of an LED or other suitable visual indicator, and a collaborate button 9 . The collaborate indicator 7 signals to the user that the party (or at least one party in a multiparty call) has the capability of collaborating with the user. The user may operate the collaborate button 9 if he or she wishes to run a collaboration application. The term “collaboration”, as used in this specification, refers to one of a number of desktop collaboration application programs, excluding voice, which allow for enhanced communication between one or more people via their desktop computers (PCs). The term “virtual co-location” will be used to describe the capability of these applications. Such applications typically run on the PC 3 at a user's desktop, or at least have their user interfaces on the desktop PC 3 . Examples of such applications include video conferencing; multiple viewing access via remote PCs to a single document; PC based joint document editing; network “white boarding”, etc. The operation of these collaboration application programs is beyond the scope of this specification although the structure and operation thereof would be well known to a person of ordinary skill in the art. A collaboration control program runs on each PC 3 associated with a telephone 1 . This program has the capability of communicating over the LAN 5 with the phone 1 to control the collaborate indicator 7 and sense actuation of the collaborate button 9 . The collaboration control program includes a list of all collaboration application programs installed which have been registered with the collaboration control program on the PC 3 , including information about their capabilities and communication protocols (e.g. H.323). The collaboration control program has the capability of launching a collaboration application program, or, in the event that it is already running in the background, to bring the collaboration application program to the foreground. This is accomplished using well known capabilities of the PC Operating System. The collaboration control program also has the ability to communicate with the collaboration control programs of remote PCs via the LAN 5 . It has the capability to request (or respond to a request for) a list of collaboration application programs from a remote PC via the PC's Operating System. Finally, it has the capability to compare remote and local collaboration application programs and, by comparing supported protocols, determine whether the mutual collaboration application programs can inter-operate in a shared work environment. With reference to FIG. 2 , two similar stations (“Station 1 ” and “Station 2 ”), of the variety shown in FIG. 1 , are interconnected over the LAN 5 and are supported by a common call control unit 11 for implementing various telephony applications. Operation of the call control unit 11 is beyond the scope of this disclosure, although the structure and operation thereof would be well known to a person of ordinary skill in the art. The call control unit 11 includes a plurality of Phone Proxies (software objects), respective ones of which are associated with telephones registered to the system. Each Phone Proxy maintains the call state for an associated telephone and includes a database containing both the telephone Number and IP Address of the phone as well as the IP address of any PC associated with the Phone (i.e. on the same user's desktop). This IP address is typically registered once, at the time of system installation. FIG. 3 illustrates only the basic steps of a call setup, call progress tone generation (dial, ringback, busy) having been omitted for ease of explanation. Also, normal call control exceptions (e.g. Called Party Busy, No Answer, etc.), and error handling routines, have also been omitted. The terms “Phone- 1 ” and “Phone- 2 ” refer to combinations of specific telephone hardware and associated control software proxies, wherein Phone- 1 is the calling party and Phone- 2 is the called party. After Phone- 1 goes off-hook and the caller dials the number of the party at Phone- 2 , Phone- 1 sends the dialed digits to the Phone- 1 Proxy running in Call Control Unit 11 . Once the Proxy recognizes the dialed number, the Phone- 1 Proxy then initiates call setup with Phone- 2 . Once Phone- 2 goes off-hook, the Phone Proxy(s) send the IP address of the Phone- 2 voice port to Phone- 1 , and vice versa, thereby enabling the phones to establish duplex voice paths, and the call is completed. Initial setup of the collaborate indicator 7 is initiated by a Call Completed event as set forth above. The Call Complete event indicates that calling and called parties to an IP voice session are “connected”. In general, this event occurs at both the calling and called party Phone Proxies, and again if additional parties are added to build a voice conference. As shown in FIG. 4 , if both parties each have at least one common collaboration application program supporting at least one protocol in common then the collaborate indicator 7 is illuminated. Conversely, if the parties do not share a collaboration application program in common, or the situation is indeterminate, the collaborate indicator 7 will not be illuminated. Following a Call Completed event (or multiple Call Complete events if there are multiple parties to the call), the Phone- 1 Proxy notifies the collaboration control program running in PC 3 of the IP address of Phone- 2 , and requests the IP address of its associated PC. Once Phone- 2 responds with the requested IP address, the collaborate control program in the PC associated with Phone- 1 requests information on collaboration application programs supported by the PC of Phone- 2 . More, particularly, Phone- 1 requests the list of collaboration application programs maintained by the collaboration control program in PC 3 associate with Phone- 2 . Once that information has been received, the local collaborate control program compares its list of supported application programs with those supported by the remote PC and, in the event of at least one match, sends a message to Phone- 1 to illuminate the collaborate indicator 7 . A tear-down process occurs in the event of one party hanging-up on the call (multiple hang-up events occurring in the event of a multi-party conference), as shown in FIG. 5 . The phone used by the party which is hanging up notifies Phone- 1 of the Hang-up event. Phone- 1 then notifies the collaborate control program of the Hang-up event. The collaborate control program determines whether any of the remaining parties to the call can collaborate, in which case the collaborate indicators remain illuminated. If there are no remaining parties capable of collaboration, or if Phone- 1 hangs up, then the collaborate control program for Phone- 1 sends a message to extinguish the collaborate indicator 7 at Phone- 1 . Thus, the collaborate indicator 7 remains illuminated provided that at least one other party remains in the call with the capability to collaborate with the initiating telephone (Phone- 1 ). Operation of the collaborate button 9 is set forth with reference to FIG. 6 , from which it will be noted that the button takes no action unless the collaborate indicator 7 is lit. In response to user actuation of button 9 , Phone- 1 notifies its associated collaborate control program. If the local indicator 7 is extinguished, then no further action is taken. The step “Phone- 1 CI lit?”, may be omitted in response to user selection. If the local indicator 7 is illuminated, the collaborate control program determines whether there is more than one collaboration application program available. If not, then the collaborate control program launches or brings the collaboration application to the foreground at the user's desktop. A similar message may be sent to the collaborate control program at the remote party so that the collaborating applications launch simultaneously. If more than one collaboration application program is available, then a dialog box is displayed at the user's desktop PC 3 listing the collaboration applications available. Once the user selects an application, program flow returns to the collaborate control program for launching the application. Referring to FIG. 7 , a general architecture is presented wherein the LAN is generalized to include the Internet 13 . In this case, Station 1 and Station 2 can be located anywhere geographically provided that they have Internet, or other network access. Non-Internet communications terminals (e.g. terminals located at a private home) are represented by Station 3 and Station 4 . Station 3 is illustrated as a PC with multimedia microphone and speakers and running an IP telephony protocol supported by an Internet Service Provider 15 . Interconnection to the ISP is via the PSTN (Public Switched telephone Network) using an arbitrary protocol (e.g. IP/PPP/33.6 Modem or ISDN BRI). In this scenario, the function of the collaboration control program may be performed either by the ISP 15 or the PC in Station 3 . If Station 1 calls Station 3 , it will respond provided that it is running H.245 or other suitable protocol. Station 4 is shown implementing a Plain Old telephone Service (POTS) termination. Station 1 can communicate with Station 4 via a PSTN gateway 17 , in a well known manner. The gateway 17 may or may not respond to a collaboration control program request from Station 1 . In any event, the collaboration control program of Station 1 will not recognize collaborative capabilities and the collaborate indicator of Station 1 therefore remains un-illuminated. FAX is, arguably, the third most pervasive form of collaboration (face-to-face communication and telephone communication being the first and second most pervasive, respectively). Thus, as an alternative Station 3 and/or Station 4 of FIG. 7 may have associated FAX applications ranging from a FAX machine to FAX emulation software. In this case, it is preferred that Station 3 or the ISP 15 and PSTN gateway 17 be implemented in such a way as to respond to a capabilities query by indicating FAX capability. Similarly it is preferred that collaboration application program suite on Stations 1 and 2 include FAX capability. Numerous alternatives and variants of the invention are possible. Some or all of the functions described herein as being implemented via the call control unit phone proxies may be implemented physically within each telephone 1 (e.g. via a H.323 IP Phone). Rather than using separate connections from phone 1 to LAN 5 and PC 3 to LAN 5 , alternative “one wire to the desktop” configurations may be adopted. In one embodiment, the phone 1 is connected directly to the LAN 5 and the PC 3 is connected to phone 1 , such that the phone 1 routes or switches PC data streams to/from the LAN 5 . In the second embodiment, the PC 3 is connected directly to the LAN 5 and the phone is plugged into the PC 3 , such that the PC routes or switches phone voice traffic to/from the LAN (i.e. the telephone is a PC peripheral). It is possible to implement either the collaborate indicator 7 or the collaborate button 9 (or both) on the PC 3 . For example, the collaborate indicator 7 could simply be part of an application user interface and the collaborate button 9 could be either a soft button activated with the mouse or a “function” key on the PC keyboard (i.e. similar to a client-server architecture). The system described herein employs an identifiable call control unit 11 (e.g. Server PC). It is equally possible that the invention may be applied in a peer-to-peer architecture, (e.g. employing H.323 protocol). The foregoing description refers mainly to two-party collaboration, however the method of this invention is applicable, with minor modifications, to multiparty collaboration. The preferred deployment of this invention is in a system in which telephone (voice) transport is effected via the data network (e.g. using a corporate LAN, WAN, or the Internet). However, such is not a requirement for realizing the invention which, it is contemplated, could in principle be implemented on top of dedicated telephone (e.g. PBX, PSTN, ISDN), with data systems to connect telephone and PC at the desktop. The telephone 1 and PC 3 may or may not be physically connected at the desktop. Further architectural detail of this implementation are not described but would be well known to a person of ordinary skill in the art. The present invention can be implemented by remote computers connected over a network. Although the embodiment described hereinabove has been described with reference to a separate telephone, the telephone equipment can be integrated within the computer and the indicator and collaborative button can be provided by an input device of the computer e.g. a keyboard. The voice capability of the telephone can be provided by a microphone input into the computer as is well known in the art. Since the present invention can be implemented by a computer program operating on a computer, the present invention encompasses a computer program and any form of carrier medium which can carry the computer program e.g. a storage medium such as a floppy disk, CD ROM, programmable memory device, or magnetic tape, or a signal such as optical signal or an electrical signal carried over a network such as the Internet. A signal is understood to mean a transmission medium. All such alternative embodiments and variations are believed to be with the scope of the invention as defined by the claims appended hereto.

A collaborative computer telephony system, comprising a communication network; a plurality of integrated computer telephony devices connected to the network and identified by unique IP addresses, at least two of the integrated computer telephony devices supporting collaboration application programs; an indicator on at least one of the integrated computer telephony devices; and a collaborate control program associated with each of the integrated computer telephony devices for detecting commonly supported ones of the collaboration application programs and in response activating the indicator.

big_patent

FIELD OF THE INVENTION [0001] The present invention relates to the insertion of clips or advertising sequences into a sequence of video pictures. BACKGROUND OF THE INVENTION [0002] With the arrival of the distribution of video content over the Internet, advertising is considered by the players of the domain such as Yahoo™, Google™ or Microsoft™ as a key element of growth. Different tools have been developed for this purpose to increase the visual impact of the inserted advertising in the video, while avoiding inconveniencing the spectators. [0003] In particular, Microsoft™ has developed a tool called VideoSense described in the document entitled “VideoSense: a contextual video advertising system”, Proceedings of the 15th international conference on Multimedia, pp 463-464, 2007. This tool was created to insert advertising clips into a video sequence, the objective being to select a clip that is relevant to the video sequence and insert it at key moments in the video, not only at the start and end of the video sequence. To select the clip to insert, low-level parameters of the colour, movement or sound rhythm type are extracted form the clip and the sequence, then compared with each other, the clip selected then being the one having the low-level parameters closest to those of the video sequence. Additional information, such as a title associated with the clip or with the sequence and supplied by the advertisers or the broadcaster of video content or text information contained in the clip or the sequence, are also used to select the clip to insert into the sequence. Once selected, the clip is inserted at particular points of the sequence, and more specifically at points of the sequence for which the discontinuity is high and at which the attractiveness is low, for example at the end of a scene or a shot not comprising any movement. [0004] The selected clip is therefore generally placed after a shot change. Although the video content of the selected clip is related to the content of the sequence in which it is inserted, the impact of this shot change on the perception of the clip by the spectator is neglected. Indeed, a phenomenon observed by several studies, particularly in the document entitled “Predicting visual fixations on video based on low-level visual features” by O. Le Meur, P. Le Callet and D. Barba, Vision Research, Vol. 47/19 pp 2483-2498, September 2007, on the temporal extension of the fixated zone after a shot change is not taken into account. The result of these studies is that the spectator continues to fixate, for an approximate time of 200 to 300 ms after the shot change, the area that he was fixating before the shot change. Hence, the area looked at by the spectator depends, not on the pictures displayed at the current time, but on pictures displayed previously. This phenomenon is illustrated by FIG. 1 . The line of pictures in the upper part of the figure represented by a video sequence comprising 7 pictures separated from each other by a time interval of 100 ms. A shot change occurs between the third and fourth picture of the sequence. The line of pictures in the is lower part of the figure shows, by white dots, the picture areas fixated by the spectator. It is noted that the spectator only shifts his fixation at the end of the sixth picture, namely 2 pictures after the shot change. This temporal extension is due to different factors, particularly to the temporal masking, to the surprise effect and to the time biologically necessary to reinitialise the action of perception. In the case of a 50 Hz video, this temporal extension lasts for about 15 pictures after the shot change. [0005] If the interesting regions of the advertising are not positioned at the same points as those of the video sequence before the shot change, the content of the advertising is therefore not immediately perceived by the spectator and the visual impact of the advertising on the spectator is therefore reduced. There is no direct perception of the message carried by the advertising. SUMMARY OF THE INVENTION [0006] One purpose of the present invention is to optimise the visual impact of an advertising clip inserted into a video sequence. [0007] For this purpose, it is proposed according to the invention to account for, in the selection process of the advertising clip to insert, the regions of interest of the video sequence and of the advertising clip in such a manner that there is a continuity between the regions of interest of the pictures of the video sequence and the regions of interest of the advertising clip. The content of the clip will be more rapidly perceived by the spectator. [0008] The present invention therefore relates to a method for processing pictures intended to insert an advertising clip at a point, called insertion point, between two pictures of a sequence of video pictures, called video sequence, comprising the following steps: generating a salience map representing the salience of the video sequence before said insertion point, generating, for each advertising clip of a set of advertising clips, a salience map, determining, for each advertising clip of said set of advertising clips, a degree of similarity between the salience map of the video sequence and the salience map of said advertising clip; said degree of similarity being representative of the comparison between the location of the salience zones on both said maps, selecting, among said set of advertising clips, the advertising clip having the highest degree of similarity, and inserting the advertising clip selected into the video sequence at the insertion point. [0014] Hence, the inserted advertising clip is the one providing, at the level of the insertion point, the best continuity in terms of salience between the video sequence and the advertising clip. [0015] According to particular embodiment, the insertion point is a point of the video sequence corresponding to a shot change in the video sequence. [0016] According to a particular embodiment, the salience map representative of the salience of the video sequence before the insertion point is generated from the salience maps of the last n pictures of the video sequence that precede the insertion point, n being comprised between 1 and 50. For example, the average is made of the salience maps of the last 15 pictures of the video sequence before the insertion point in the case of a 50 Hz video. [0017] According to one embodiment, the salience map of the advertising clip is generated from the salience maps of the first p pictures of the advertising clip, p being comprised between 1 and 50. For example, the average is made of the salience maps of the first 15 of the clip in the case of a 50 Hz video. [0018] A clip is therefore selected providing a continuity in terms of salience between the last pictures of the video sequence before the insertion point and the start of the advertising clip. [0019] According to a particular embodiment, the degree of similarity of an advertising clip is determined by calculating the correlation coefficient between the salience map of the video sequence and the salience map of said advertising clip, the degree of similarity thus being proportional to the correlation coefficient calculated. [0020] According to another particular embodiment of the method of the invention, the degree of similarity for an advertising clip is determined by calculating the Kullback-Leibler divergence between the salience map of the video sequence and the salience map of said advertising clip, the degree of similarity thus being inversely proportional to the divergence calculated. [0021] According to another particular embodiment, to determine the degree of similarity of an advertising clip, the following steps are carried out: selecting, from the salience map of the video picture and from the salience map of the advertising clip, the N most salient points of the map, called maximum salience points, said points being separated from each other by at least m points and ordered from the most salient to the least salient, N being greater than or equal to 1, determining, for each of the N maximum salience points of the salience map of the picture, the Euclidean distance between said point and the maximum salience point of the same order of the salience map of the advertising clip, and calculating the average of the N Euclidean distances determined, the degree of similarity thus being inversely proportional to the calculated average. [0025] In this embodiment, the Euclidean distance being determined between the maximum salience points of the same order, the salience value of the points is, to a certain extent, taken into account in determining the degree of similarity. [0026] According to a variant embodiment, the N maximum salience points are not ordered. In this embodiment, the determination of the degree of similarity of an advertising clip comprises the following steps: selecting, from the salience map of the video picture and from the salience map of the advertising clip, the N most salient points of the map, called maximum salience points, said points being separated from each other by at least m points, N being greater than or equal to 1, determining, for each of the N maximum salience points of the salience map of the video picture, the Euclidean distance between said point and the closest maximum salience point in the salience map of the advertising clip, and calculating the average of the N Euclidean distances determined, the degree of similarity thus being inversely proportional to the calculated average. [0030] In these last two embodiments, the selection of N maximum salience points separated by at least m points in a salience map is carried out in the following manner: [0031] a) the point having the maximum salience is selected from said salience map, [0032] b) all the points belonging to a zone of radius R around said detected point are inhibited, R being equal to m points, and [0033] c) the steps a) and b) are repeated for the non-inhibited points of the salience map until the N maximum salience points are obtained. [0034] The present invention also relates to device for processing pictures intended to insert an advertising clip at a point, called insertion, of a sequence of video pictures, called video sequence, comprising: means for generating a salience map representative of the salience of the video sequence before the insertion point and a salience map for each advertising clip of a set of advertising clips, means for determining, for each advertising clip of said set of advertising clips, a degree of similarity between the salience map of the video sequence and the salience map of said advertising clip. means for selecting, among said set of advertising clips, the advertising clip having the highest degree of similarity, and means for inserting the advertising clip selected into the video sequence at said insertion point. [0039] According to a particular embodiment, the device further comprises means for detecting a shot change in the video sequence, the selected advertising clip thus being inserted at the point of the video sequence corresponding to this shot change. BRIEF DESCRIPTION OF THE DRAWINGS [0040] The invention will be better understood, and other purposes, details, characteristics and advantages will appear more clearly during the following detailed explanatory description of several currently preferred particular embodiments of the invention, with reference to the annexed diagrammatic drawings, wherein: [0041] FIG. 1 , already described, illustrates the phenomenon of temporal extension after a shot change in a video sequence, [0042] FIG. 2 shows a functional diagram of the method of the invention, [0043] FIG. 3 is a flowchart showing the steps of the method of the invention, [0044] FIG. 4 illustrates the determination of a degree of similarity between the salience map of an advertising clip and the salience map of the video sequence according to a first embodiment, [0045] FIG. 5 illustrates the determination of a degree of similarity between the salience map of an advertising clip and the salience map of the video sequence according to another embodiment, and [0046] FIG. 6 diagrammatically shows a device capable of implementing the method of the invention. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS [0047] In the rest of the description, advertising clip is understood to mean a series of fixed or animated pictures displaying an advert or a logo and insertion point is understood to mean the point between two pictures of the video sequence into which the advertising clip is inserted. [0048] According to the invention, the regions of interest of the last pictures of the video sequence before the insertion point and the regions of interest of the advertising clips of a predefined set of advertising clips are determined and the advertising clip having the regions of interest spatially closest to those of the last pictures of the video sequence before the insertion point are selected. This insertion point can be predefined or be manually defined at the start of the method by an operator or be defined automatically at the start of the method. [0049] The insertion point is advantageously a point of the video sequence corresponding to a shot change so that the spectator is not inconvenienced or disturbed by the sudden appearance of an advertising clip in the video sequence. [0050] FIG. 2 is a functional diagram of the method of the invention in which the insertion point (point of the video sequence in which the advertising clip is inserted) corresponds to a shot change. According to the invention, the regions of interest of the last pictures of the video sequence before the shot change and the regions of interest of the advertising clips of a predefined set of advertising clips are determined and the advertising clip having the regions of interest spatially closest to those of the last pictures of the video sequence before the shot change are selected. The location of this shot change can be contained in metadata associated with the video sequence or defined at the start of the method. The shot change can be detected automatically, for example by an algorithm such as the one described in the document “Information Theory-Based Shot Cut/Fade Detection and Video Summarization” by Z. Cerneková, I. Pitas and C. Nikou, IEEE transactions on circuits and systems for video technology, Vol. 16, no. 1, January 2006) or selected manually by an operator. [0051] FIG. 3 more particularly illustrates the steps of the method of the invention. According to a first step E 1 , a salience map is generated representing the salience of the video sequence before the said insertion point. This salience map is for example the salience map of the last picture of the sequence before the insertion point or then the average of the salience maps of the last n pictures of the sequence before the insertion point. The methods for generating the salience maps are fully known by those skilled in the art. Such a method is for example described in the patent application EP 1 544 792. Such a map associates each pixel of the video picture with a point having a given salience value. The higher the salience value of the point, the greater the interest of the associated pixel and the more this pixel attracts the attention of the spectator. The salience value of the points is for example comprised between 0 and 255 (8 bits). [0052] According to a step E 2 , a salience map is then generated for each of the advertising clips of the set of clips. This salience map is advantageously defined from the first pictures of the advertising clip, for example from the p first pictures. The salience map of a clip is for example the average of the salience maps of the p first pictures of this clip. [0053] According to the next step, referenced E 3 , for each advertising clip, a degree of similarity is determined between the salience map of the video sequence and the salience map of the advertising clip. [0054] This degree of similarity can be determined in different manners. [0055] According to a first embodiment, the step E 3 consists in calculating, for each advertising clip, the correlation coefficient between the salience map of the video sequence and the salience map of the advertising clip, the degree of similarity thus being proportional to the correlation coefficient calculated. [0056] According to a second embodiment, the step E 3 consists in calculating, for each advertising clip, the Kullback-Leibler divergence between the salience map of the video sequence and the salience map of the advertising clip, the degree of similarity thus being proportional to the divergence calculated. [0057] According to a third particular embodiment, the step E 3 consists in carrying out, for each advertising clip, the following sub-steps: [0058] (a) in the salience map of the video sequence and in the salience map of the advertising clip, a selection is made of the N most salient points of the map, called maximum salience points, the points being separated from each other by at least m points and ordered from the most salient to the least salient; to achieve this, a selection is first made of the point having the maximum salience in the salience map; then, a zone of m points surrounding the detected point is inhibited; among the non-inhibited points of the salience map, the point having the maximum salience is then detected and all the points belonging to a radius R equal to m points around this maximum salience point are inhibited; the operation is repeated until the N maximum salience points are obtained; N points are thus obtained in the salience map of the video sequence and N points in the salience map of the advertising clip, [0059] (b) for each of the N maximum salience points of the salience map of the video picture, the Euclidean distance is then determined between said point and the maximum salience point of the same order of the salience map of the advertising clip, [0060] (c) the average of the N previously calculated Euclidean distances is calculated, the degree of similarity for the considered advertising clip thus being inversely proportional to the calculated average. [0061] This embodiment of the step E 3 is illustrated by FIG. 4 for three advertising clips. In this figure, three maximum salience points (N=3) have been identified in the video sequence V and are noted P V1 , P V2 and P V3 , with S(P V1 )>S(P V2 )>S(P V3 ) where S(P) designates the salience value of the point P. Moreover, P A1 , P A2 and P A3 designate the three maximum salience points of an advertising clip A, with S(P A1 )>S(P A2 )>S(P A3 ). Likewise, P B1 , P B2 and P A3 designate the three maximum salience points of an advertising clip B, with S(P B1 )>S(P B2 )>S(P B3 ). Finally, P C1 , P C2 and P C3 designate the three maximum salience points of an advertising clip C, with S(P C1 )>S(P C2 )>S(P C3 ) [0062] According to this figure, the step E 3 consists in calculating, for each clip, the Euclidean distance d between the points of the same order, namely d(P Vi ,P Ai ), d(P Vi ,P Bi ) and d(P Vi ,P Ci ) with iε[1 . . . 3], then in calculating, for each clip, the average of the 3 calculated distances and in deducing a degree of similarity for each of them, this degree being inversely proportional to the calculated average. The degree of similarity is for example the inverse of the calculated average. [0063] According to an embodiment that is a variant of the third embodiment, the maximum salience points selected are not ordered. Step E 3 thus consists in carrying out, for each advertising clip, the following sub-steps: [0064] (a) in the salience map of the video sequence and in the salience map of the advertising clip, a selection is made of the N most salient points of the map, the points being separated from each other by at least m; as for the previous embodiment, a selection is first made of the point having the maximum salience in the salience map; then, a zone of m points surrounding the detected point is inhibited; among the non-inhibited points of the salience map, the point having the maximum salience is then detected and all the points belonging to a radius R equal to m points around this maximum salience point are inhibited; the operation is repeated until the N maximum salience points are obtained; N points are thus obtained in the salience map of the video sequence and N points in the salience map of the advertising clip, [0065] (b) for each of the N maximum salience points of the salience map of the video picture, the Euclidean distance is then determined between said point and the closest maximum salience point of the salience map of the advertising clip, [0066] (c) the average of the N previously calculated Euclidean distances is calculated, the degree of similarity for the considered advertising clip thus being inversely proportional to the calculated average. [0067] This variant embodiment is illustrated by FIG. 5 for three advertising clips. This figure uses the maximum salience points defined for FIG. 4 . According to this embodiment, for each point P Vi of the video sequence, a calculation is made of its Euclidean distance d with each of the maximum salience points of each clip and only the smallest distance is kept. For example, in FIG. 5 , for the clip A, the point P A2 is closest to the point P V1 , the point P A2 is closest to the point P V2 and the point P A1 is closest to the point P V3 . Hence, for clip A, the average of the distances d(P V1 ,P A2 ), d(P V2 ,P A2 ) and d(P V3 ,P A1 ) is calculated. In the same manner, by referring again to FIG. 5 , a calculation is made, for the clip B, of the average of the distances d(P V1 ,P B3 ), d(P V2 ,P B3 ) and d(P V3 ,P B3 ) and, for the clip C, of the average of the distances d(P V1 ,P C1 ), d(P V2 ,P C2 ) and d(P V3 ,P C3 ). From these, a degree of similarity is thus deduced for each of the three clips that is inversely proportional to the calculated average. The degree of similarity is for example the inverse of the calculated average. [0068] Naturally, any other method making it possible to calculate the similarity between the salience map of the video sequence and the salience map of the advertising clip can be used to implement the step E 3 . [0069] By referring again to FIG. 3 , the next step, referenced E 4 , consists in selecting, from all the advertising clips, the clip having the highest degree of similarity. [0070] Finally, the advertising clip selected is inserted at a step E 5 into the video sequence at the insertion point of the video sequence. At the end of the method, an enhanced video sequence is obtained in which an advertising clip has been inserted. [0071] Naturally, the selection of the advertising clip to insert can be more complex and combined with other selection processes. The clips contained in the set of advertising clips can already have been preselected according to their semantic content with respect to that of the video sequence into which it has been inserted. For example, a first preselection of clips can have been made according to the theme of the video sequence or of the text and/or objects contained in the video sequence or also according to the profile of the spectator. [0072] The present invention also relates to a device for processing pictures referenced 100 in FIG. 6 that implements the method described above. In this figure, the modules shown are functional units that may or may not correspond to physically distinguishable units. For example, these modules or some of them can be grouped together in a single component, or constitute functions of the same software. On the contrary, some modules may be composed of separate physical entities. Only the essential elements of the device are shown in FIG. 6 . The device 100 notably comprises: a random access memory 110 (RAM or similar component), a read-only memory 120 (hard disk or similar component), a processing unit 130 such as a microprocessor or a similar component, an input/output interface 140 and possibly a man-machine interface 150 . These elements are connected to each other by an address and data bus 160 . The read-only memory contains the algorithms implementing the steps E 1 to E 5 of the method according to the invention. If the device is responsible for detecting a change in the video to sequence to insert an advertising clip into it, the memory also contains an algorithm for detecting shot changes. When powered up, the processing unit 130 loads and runs the instructions of these algorithms. The random access memory 110 notably comprises the operating programs of the processing unit 130 that are responsible for powering up the device, as well as the video sequence to process and the advertising clips to insert into this video sequence. The function of the input/output interface 140 is to receive the input signal (the video sequence and the advertising clips), and output the enhanced video sequence into which the advertising clips was inserted. Possibly, the operator selects the shot change into which the advertising clip is to be inserted by means of the man-machine interface 160 . The enhanced video sequence is stored in random access memory then transferred to read only memory to be archived with a view to possible future processing. [0073] Although the invention has been described in relation to different particular embodiments, it is obvious that it is in no way restricted and that it comprises all the technical equivalents of the means described together with their combinations if the latter fall within the scope of the invention. Notably, the advertising clip can be inserted at points of the videos sequence that are not shot changes. The clip can for example be inserted at a specific point of the sequence defined in the metadata accompanying the video sequence. It can also possibly be inserted at regular intervals of time into the sequence.

The present invention relates to a method for processing pictures intended to insert an advertising clip at a point, called insertion, between two pictures of a sequence of video pictures, called video sequence, comprising the following steps: generating a salience map representing the salience of the video sequence preceding the insertion point, generating, for each advertising clip of a set of advertising clips, a salience map, determining, for each advertising clip of said set of advertising clips, a degree of similarity between the salience map of the video sequence and the salience map of said advertising clip, said degree of similarity being representative of the comparison between the location of the salience zones on both said maps, selecting, among said set of advertising clips, the advertising clip having the highest degree of similarity, and inserting the advertising clip selected into the video sequence at the insertion point.

big_patent

FIELD OF THE INVENTION [0001] This invention relates to the use of a recessed mask structure to prevent localized high electrical fields at intersections with resulting lower electrical breakdown, in very small dimension semiconductor devices such as would be encountered in high speed and high density integrated circuit applications and chip interconnect structures with fine metal features and low dielectric constant insulators. BACKGROUND OF THE INVENTION [0002] In the miniaturizing of semiconductor devices, as the spacing and dimensions approach the below 150 nanometer range, dimensional tolerances become very small and abrupt physical discontinuities such as interfaces between different materials produce high electrical fields that in turn result in enhanced leakage and breakdown. Further, at such small dimensions, different materials than commonly used heretofore, with different properties such as lower dielectric constant (k), are being found attractive for use in lowering such device paramaters as line to line capacitance, reducing cross talk noise and power dissipation. Still further, the different materials in turn behave differently in processing. [0003] An illustration of many of the considerations involved in developing integrated circuit interconnect structures and processes where the dimensions are in the sub 250 nanometer range appears in the 7 page technical article titled “Pursuing The Perfect Low-k Dielectric”, by Laura Peters, and appearing in Semiconductor International Magazine in the Sep. 1, 1998 issue. [0004] There is a clear need in the art for a capability that will operate to provide relaxation of limitations and to reduce complexity of the situations that are being encountered in providing interconnect structures and in the fabrication thereof in the sub 250 nanometer dimension range. SUMMARY OF THE INVENTION [0005] A metal plus low dielectric constant (low-k) interconnect structure is provided for a semiconductor device wherein adjacent regions in a surface separated by a dielectric have dimensions in width and spacing in the sub 250 nanometer range, and in which reduced lateral leakage current between adjacent metal lines, and a lower effective dielectric constant than a conventional structure, is achieved by the positioning of a differentiating or mask member that is applied for the protection of the dielectric in subsequent processing operations, at a position below a surface to be planarized, where there will be a lower electric field. The mask position, is in the range of about 0.5 to 20 nanometers, with 5 nanometers being preferred, below the surface to be planarized, at a location where the surfaces of the regions separated by the dielectric are undisturbed and have complete integrity. The invention is particularly useful in the damascene type device structure in the art wherein adjacent conductors lined with an electrically conductive and diffusion barrier film are disposed in thin trenches in an intralevel dielectric material (ILD), connections are made to levels above and belowthrough metal filled vias is the ILD, masking is employed both to protect the dielectric material between conductors during processing operations, and to assist in patterning those trenches within the interlevel dielectric material. A dielectric cap is also usually applied over the surfaces of the metal lines and the masking layer, to further separate successive levels of metal wiring. BRIEF DESCRIPTION OF THE DRAWINGS [0006] [0006]FIGS. 1A and 1B are dimensionally correlated schematic depictions of a structure of sub 250 nanometer conductive regions at a planarized surface correlated with a graph indicating the locations of high electric field concentrations and illustrating uneven features of the conductive region walls and the present location in the art of masking of the dilectric between conductive regions. [0007] [0007]FIG. 2 is a schematic depiction of a prior art intersection of conductive members with a planarized surface such as in present in a standard dual damascene type coplaner mask layer and metal such as copper surface. [0008] [0008]FIGS. 3 and 4 are depictions of structures in the invention wherein the intralevel dielectric is positioned below and away from the high electric field locations [0009] [0009]FIG. 5 is a graph of capacitance vs thickness of mask positioned in accordance with the invention illustrating an overall lower capacitance of the inventive structure. DESCRIPTION OF THE INVENTION [0010] Referring to FIG. 1A in the interlevel dielectric member 1 there are illustrated, as an example two essentially parallel conductive regions 2 and 3 . In the sub 250 nanometer dimension range for the width of and separation between elements, a problem is encountered when there is a facetted region 4 where the elements 2 and 3 intersect with the surface 5 which produces pointed locations 6 - 9 , at which field lines are concentrated thereby producing a high electric field which in turn can cause an electrical breakdown at the pointed region and possibly through any diffusion barrier, which may be a conductive diffusion barrier liner 10 . In applications involving metals such as copper, aluminum, silver, gold, and tungsten and alloys thereof, the liner 10 which is usually of tantalum, titanium, tin, or nitrides thereof, routinely serves as a diffusion barrier to any migration. Commonly, the liner 10 may be damaged, thinned or removed in the pointed locations 6 - 9 during processing. The metal conductor, such as copper, may then migrate onto the surface 5 because the liner 10 has been disturbed. As would be known in the art, the facetted region 4 may have a curved radius or a complex shape. The exact shape shown in FIG. 1A being only an example. [0011] In FIG. 1B a graph is provided of electric field intensity vs distance across the surface 5 correlated with high electric field concentrations in FIG. 1A. As illustrated in FIG. 1B the higher electric field is not only corresponding to the pointed regions but also extends across the conductive members 2 , 3 . [0012] Referring to both FIGS. 1A and 1B; the problem produced by the pointed regions 6 - 9 appears, at this state of the art, to be inherent in dry etching processes such as reactive ion etching, which would be employed in patterning operations at the surface 5 . A mask layer 11 , shown dotted, is positioned everywhere over the dielectric 1 , to protect the dielectric 1 during any operations at the surface 5 . One such operation for example would be a deposition followed by a chemical-mechanical planarization of a conductor material 2 , 3 . A second example is a deposition of further structure or a dielectric cap 13 , shown dotted. [0013] The materials of which masks are made vary in both reactive on etch resistance and in dielectric constant and thus present further considerations in fabrication process selection. Acceptable mask materials are amorphous silicon, carbon, hydrogen (∝-Si:C:H); silicon, carbon, oxygen, hydrogen alloys (organosiloxane or Si:C:O:H); silicon, nitrogen, carbon alloys (Si:N:C); silicon nitride(Si 3 N 4 ); silicon dioxide (Si O 2 ); and, silicon oxynitride (SiON). [0014] The facetted region 4 problem has a detrimental effect on flexibility in the use of materials with different properties and in meeting processing specifications. Of particular concern is the interface between mask layer 11 and the cap layer 13 , with the pointed locations 6 - 9 as shown in FIG. 1A. There are also other aspects of the problem of facetted regions. The pointed regions 6 - 9 result in smaller line spacing which in the presence of the higher than desirable electric field may result in leakage and breakdown. In general, the presence of the pointed regions 6 - 9 and the resulting high electric fields is a source of breakdown failures in devices. The mask 11 to cap 13 interface is the location of many of that type of breakdowns of the interface particularly at locations 6 - 9 and across the conductors 2 , 3 where the electric field is magnified as shown in FIG. 1B. A greater propensity for electrical shorting between adjacent lines may also be encountered. [0015] In accordance with the invention a structure and process are provided in which the interface between the mask 11 and cap 13 in FIG. 1A is arranged to be placed at a location that is away from the high electric field points, 1-20 nanometers for example with 2-5 nanometers being preferred; and where the very thin conductive liner diffusion barrier 10 surrounding the conductive members 2 and 3 will have integrity that has not been disturbed by processing up to that point. [0016] Referring to FIG. 2, a schematic depiction is provided of a prior art type standard dual damascene structure with a mask layer 16 and a coplanar mask surface 16 ′ with a metal such as Cu conductor element 2 , 3 surface. The facetted problem at points 6 - 9 is present. In all the Figures the same reference numerals are used for identical elements where appropriate. [0017] A schematic depiction of is provided of the structure of the invention in the structures shown in FIGS. 3 and 4, wherein a portion 14 of the mask layer 16 , has been removed providing a mask to cap interface area 5 ′ that is not coplanar with the pointed locations 6 - 9 , as a result, in the invention, the mask member 16 itself is then positioned so that the high field points 7 and 8 are separated from the interface 5 ′ and the interfaces 17 and 18 of the mask 16 are at portions of the conductive members 2 and 3 where the liner 10 is undisturbed. Such disturbance frequently occurs during chemical-mechanical processing, and is frequently mainfested as damage to the liner 10 near the locations 6 - 9 . The portion of the low k dielectric material 1 , being covered and protected by the mask 16 , is labelled element 19 . A conformal cap layer is labelled element 20 . [0018] The mask 16 is usually of a harder low k dielectric, such as amorphous silicon, carbon, hydrogen (∝-Si:C:H); silicon, carbon, oxygen, hydrogen alloys (organosiloxane or Si:C:O:H); silicon, nitrogen, carbon alloys (Si:N:C); silicon nitride(Si 3 N 4 ); silicon dioxide (Si O 2 ); and, silicon oxynitride (SiON). The liner 10 may be a conductive diffusion barrier film such as Ta, Ti, TaN, TiN, W or WN or combinations thereof. Examples of low k ILD materials are listed in the above referenced Semiconductor International Magazine article. [0019] Referring to FIG. 4, the cap element 20 is typically conformally deposited over the surfaces 5 ′. Many standard deposition processes of the plasma enhanced chemical vapor deposition type produce a conformal cap layer 20 as shown. Alternatively, the top surface 23 of the cap 20 can be made approximately planar using a deposition process consisting of a conformal step followed by planarizing step to level discontinuities. [0020] The recessed mask structure is achieved through a unique process that permits both:the benefit of having a recessed surface of the mask with respect to a device surface where there may be aspects to avoid, such as high electric field concentration points; and the benefit of having a final mask thickness that is selectable and no thicker than necessary. Mask material generally has a k value that is higher than the ILD material k value thus increasing the overall capacitance value so that using quantities for as thin a mask as possible is desirable. The process in general involves removing mask material between points 7 and 8 after chemical-mechanical polishing, down to a level that is away from the surface 5 where the high fields, points 7 and 8 are located and continuing until a selected mask thickness, dimension 21 , is reached. [0021] Another embodiment of the invention involves using the material silicon nitride as the mask 16 . The etch process to decrease the layer 16 to dimension 21 is performed through the use of an etch tool such as is available in the art from the Applied Materials corporation identified as IPS and using with the tool a mixture of gasses chosen from the group of O 2 ;CH 3 F;CH 2 F 2 ;Ar;NH 3 ;NF 3 ;He; and H 2 . The gas flow rate is in the range of 1-100 sccm; at a power of 100-300 watts, at a pressure in the range of 1 to 100 milliTorr with a bias power of the range of 50-500 watts. [0022] Still another alternative involves no mask layer and employs an inorganic material for the intralevel dielectric selected from the group of silicon dioxide, fluorosilicate glass, and carbon doped oxide. In this alternative the intralevel dielectric is recessed by etching below the surface of the conductors 2 , 3 . [0023] There are several beneficial features achieved with the invention. The high field at points 7 and 8 are now away from the cap 20 -mask 16 interface at 5 ′. The material of the mask 16 which usually has a higher k and which can effect overall dielectric properties of the device can be minimized with dimension 21 being selected independently of consideration for the planarization process of surface 5 since it is positioned through the invention after the planarization operation. Any damage from planarization operations to the conductive liner 10 at the points 6 - 9 is minimized, so the metal Cu of 2 and 3 does not breach the barrier and contaminate the interface 5 ′. [0024] The recessed mask structure of the invention in addition to providing the above described benefits also provides, when integrated into a component, a lower and predictable overall capacitance which parameter in turn is very valuable because it results in faster signal propagation in the interconnect wiring. [0025] Referring to FIG. 5 which is a graph of capacitance vs thickness 21 of mask positioned in accordance with the invention. From the graph of FIG. 5 it is clear, that the inventive structure has a lower capacitance. [0026] Returning to FIG. 4, The material used in masking is generally referred to as hard with respect to chemical mechanical processes and such materials have a higher k value. In the structure of the invention the high k mask 16 is positioned in an opening between conductors 2 and 3 so that the overall capacitance decreases as more of the hard mask is recessed. [0027] In general with the invention there will be a smaller thickness of the high k material and what high k material there is will be recessed below the locations 6 - 9 of highest electric field. Both of these aspects lead to the lower capacitance of the invention structure. [0028] The structure of the invention, following generally FIGS. 3 and 4, is made using a standard substrate in the art of a material such as silicon on which is deposited a bulk layer of intralevel dielectric material 1 such as an organic thermoset polymer or an inorganic alloy comprised of Si, O, H or Si, C, O, H such as carbon doped oxide, in which via and trench openings as used in damascene type structures have been etched using a mask layer 16 . [0029] The etched openings 2 and 3 are provided with conductive diffusion barrier liners 10 of Ta, Ti, TaN, TiN, W or WN, by chemical or physical vapor deposition. The liner 10 in this process which serves as an adhesion layer between the intralevel dielectric and a thin copper layer, not shown, is used in this process as an electroplating conductor for electroplating more copper into and filling the openings 2 and 3 . The surface 5 is then chemically-mechanically polished until the copper conductors are nearly coplanar with the mask surface 16 ′. A different, chemical-mechanical slurry is then used to remove any remaining liner 10 material which step may disturb the liner 10 . [0030] The partially processed substrate is gently etched with a downstream plasma or reactive ion etch tool to more the interface 5 ′ away from the surface 5 to establish the dimension 21 . In a preferred method this is done with a plasma tool wherein the sample being bombarded is placed at a temperature of 250 degrees C. downstream from a 950 watts inductive RF field in a forming gas atmosphere for about 10 to 200 seconds with 100 being preferred. The downstream location may be viewed as being out of the line of sight between the substrate and the plasma. Using an etch tool, such as for example the one available in the art known as the Mattson ICP; and in a forming gas in a flow of about 0.5 standard liters per minute(sccm) and at a pressure of about 1.1 Torr; a satisfactory etch rate of about 2 nanometers per minute of ∝-Si:C:H is achieved. Flow rates from 0.1 to 1.0 standard liters per minute of forming gas produces the same etch rate. [0031] In an alternative structure of the invention a mask layer of a separate material can be avoided by establishing the surface of the intralevel dielectric material at a location that is in the range of between 1-20 nanometers with 2-5 nanometers being preferred, below the surface of the metal conductors. [0032] What has been described is a technology that permits the formation at small dimension interconnections between difficult to use materials in semiconductor devices by moving interfaces away from high fields and controlling capacitance through use of only as much of a high capacitance contributing ingredient as essential.

A metal plus low dielectric constant (low-k) interconnect structure is provided for a semiconductor device wherein adjacent regions in a surface separated by a dielectric have dimensions in width and spacing in the sub 250 nanometer range, and in which reduced lateral leakage current between adjacent metal lines, and a lower effective dielectric constant than a conventional structure, is achieved by the positioning of a differentiating or mask member that is applied for the protection of the dielectric in subsequent processing operations, at a position about 2-5 nanometers below a, to be planarized, surface where there will be a lower electric field. The invention is particularly useful in the damascene type device structure in the art wherein adjacent conductors extend from a substrate through an interlevel dielectric material, connections are made in a trench, a diffusion barrier liner is provided in the interlevel dilectric material and masking is employed to protect the dilectric material between conductors during processing operations.

big_patent

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the field of designing radio receivers using digital signal processing techniques. 2. Prior Art The following references are relevant to the present invention: [1] F. de Jager, "Delta modulation--a method of PCM transmission using the one unit code," Philips Res. Repts., vol. 7, pp. 442-466; 1952. [2] H. S. McDonald, "Pulse code modulation and differential pulse code modulation encoders," 1970 U.S. Pat. No. 3,526,855 (filed 1968). [3] R. Steele, Delta Modulation Systems, New York; Wiley, 1975. [4] H. Inose, Y. Yasude, and J. Murakami, "A telemetering system code modulation--Δ--Σ modulation, " IRE Trans. Space Elect. Telemetry, vol. SET-8, pp. 204-209, September 1962. [5] S. K. Tewksbury, and R. W. Hallock, "Oversampled, Linear Predictive and Noise-Shaping coders of order N>1, " IEEE Trans. Circuits Sys., vol. CAS-25, pp. 436-447, July 1978. [6] D. B Ribner, "Multistage bandpass delta sigma modulators," IEEE Trans. Circuits Sys., vol. 41, no. 6, pp. 402-405, June 1994. [7] A. M. Thurston, "Sigma delta IF A-D converters for digital radios," GEC Journal of Research Incorporating Marconi Review and Plessey Research Review, vol. 12, no. 2, pp. 76-85, 1995. [8] N. van Bavel et al., "An analog/digital interface for cellular telephony," IEEE Custom Integrated Circuits Conference, pp. 16.5.1-16.5.4, 1994. There are many advantages in using digital signal processing (DSP) techniques in the implementation of radio frequency (RF) receivers. Harnessing these advantages, however, relies to a great degree on the ability to effectively convert the signal from the analog to the digital domain. In conventional RF receiver implementations, the received signal is down converted to in-phase (I) and quadrature (Q) baseband components via one or more conversions to an intermediate frequency (IF), using analog circuitry, and then converted to the digital domain using a pair of pulse coded modulator (PCM) type analog to digital A/D converters operating at baseband. A number of sources of degradation exist in using this design approach that limit the achievable performance. Any phase error in the local oscillators used to mix the signal to I and Q baseband components will impair the receiver's ability to discriminate between signal components above and below the IF center frequency. For example, achieving 40 dB of (I-Q) discrimination requires these local oscillators to be orthogonal to within 0.5°, including all drift from aging, temperature and manufacturing tolerances. This phase accuracy must then be maintained throughout the pair of analog paths up to and including the A/D conversion function. Similarly, the amplitude response of the two analog paths, including any gain mismatch between the two A/D converters, must be well matched to preserve the (I-Q) discrimination of the receiver. Again, to obtain discrimination of 40 dB, it is necessary to match the amplitude response of the two paths to better than 0.1 dB. Such tolerances are possible and may be exceeded by using a calibration routine; however, obtaining this tolerance in a pair of digital paths is routine and therefore provides motivation of digitizing an IF signal directly and thereby avoiding these balancing issues altogether. Design approaches for direct A/D conversion of the received IF signal using conventional PCM type multiple bit A/D converters eliminate the need for the IF/Baseband analog circuitry. Although the location of a substantial number of high-speed digital switches alongside sensitive RF circuitry invites interference, the potential benefits are often considered to outweigh the new design difficulties. Another problem introduced by the digital processing of IF signals is the need to perform high-speed A/D conversion, a problem compounded by the need for higher linearity in early stages of the receiver. Conventional multiple bit A/D converters have the property that the signal bandwidth available is equal to one half of the sampling frequency, less a margin to allow for anti-alias filtering. The product of the bandwidth and resolution of a converter (or dynamic range) is a measure of its performance, and this will typically be reflected in the difficulty of designing the device and also in its market price. Because a typical IF signal is narrowband compared to its carrier frequency, the use of wideband multiple bit converters does not represent an optimal coding solution to a very specific problem. Some reduction in the A/D converter's processing overhead can be achieved by operating it in a subsampled mode such that the carrier frequency is above the sampling frequency. However, achieving the bandwidth and dynamic range design goals with this method requires enhanced channel filtering prior to the conversion to prevent other channels from aliasing into the passband resulting in an increase in cost and power consumption. A/D converters designed based on the principles of predictive and interpolative coding (such as delta converters and sigma delta converters), although traditionally operating on baseband signals--especially audio--exhibit attractive properties (see the foregoing references). First, they are an over-sampled coding technique that achieves coding accuracy by fine temporal quantization rather than fine level quantization. Thus, for a given sampling frequency, the usable bandwidth is very much reduced compared with standard pulse code modulation (PCM) techniques, and this trade-off in requirements is reflected by a simplified design suited to low tolerance components. In general, the analog filtering required with such a converter is thus comparatively simple. A second advantage of these types of coding is their inherent linearity. A multiple bit converter is very susceptible to component tolerances, and a non-linear mapping between the analog and digital domains is difficult to avoid. One very successful means of combating this effect is by the use of high-level additive dither, which effectively decorrelates the non-linearities from the input signal and reduces the effect to a benign noise source. This technique may be used to remove the non-linear effects from the coder, but the limiting performance is ultimately that of a PCM code, and this itself can introduce highly correlated distortion, which in an application comprising evenly spaced radio channels is likely to present difficulties. The use of interpolative type encoders (i.e., sigma delta converters) in the analog to digital conversion of a high frequency IF have been advocated by many authors, such as the authors of the last two references hereinbefore set forth. Although the advantages of these techniques are clearly delineated by these authors, there remain numerous implementation challenges which must be overcome by a designer who is focused on achieving the low cost and low power consumption goals. The most relevant of these challenges is the fact that although these techniques ultimately produce an oversampled single bit (1-bit) digital representation of the IF signal, the signal must first be converted from its analog continuous-time representation to an analog discrete-time-representation, where it is processed by elaborate discrete-time analog circuitry prior to being mapped into the digital domain (i.e., quantized or digitized). Furthermore, achieving the high dynamic range and the low quantization noise advantages offered by these techniques often requires the implementation of high order encoding loops, with considerable increase in complexity. BRIEF SUMMARY OF THE INVENTION This invention utilizes predictive coding principles to implement a simple down converting A/D converter. By placing the sampler inside the predictive loop, the predictive loop filter can be implemented using DSP techniques, thus eliminating the complexities introduced by use of discrete time analog circuitry. Then, by re-mapping the output of the predictive loop filter into the analog domain using a D/A converter, the predictive filter output signal is subtracted from the input analog signal to generate the prediction error signal. Therefore, through directly sampling the prediction error signal and converting the output of the predictive loop filter into analog representation using a low-cost multiple bit D/A, this invention eliminates the use of discrete-time analog circuitry and greatly reduces the complexity of the converter design. In using mostly DSP techniques in the implementation of the predictive loop, it became possible to make use of the flexibilities offered by these techniques to adapt the characteristics of the digital predictive loop to match those of the input signal. This allows attaining higher dynamic range and lower quantization noise performance with lower order and less complex predictive loops. The dynamic range performance of the digital predictive encoder of this invention is further extended by utilizing the digital output of the loop to generate the signal for controlling a variable gain amplifier placed at the front of the predictive loop input. Furthermore, the DC offset performance of the converter is greatly enhanced through incorporation of an offset nulling digital signal processing element which is used to provide an estimate of the offsets introduced by the various circuits. This offset estimate is then introduced at the input of the sampler by combining it digitally with the output of the predictive filter. This invention is distinguished from prior art described in the references listed in the Prior Art section in four major aspects. First, the placement of the sampler inside the predictive loop allows the predictive filter to be implemented using DSP techniques, thus reducing the complexity of the overall converter plus adding flexibility in re-programming the predictive filter characteristics, which results in improvement in the converter dynamic range and noise performance. Second, operating the predictive encoder in a subharmonic mode allows the predictive loop to downconvert the signal and realize a further reduction in the complexity of the digital logic used in implementing the predicting digital filter. Third, using the digital predictive loop output to control the gain level applied to the input signal allows further increase of the dynamic range of the converter. Fourth, incorporating a built-in offset nuller which eliminates biases introduced by the implementation circuits' imperfections dramatically enhances the DC offset performance of the analog to digital conversion process. BRIEF DESCRIPTION OF THE FIGURES FIG. 1 is a block diagram of the Downconverting Digitizer of the present invention. FIG. 2 is a detailed block diagram of the sampler of FIG. 1. FIG. 3 is presents a generalized structure of the predictive filter of FIG. 1. FIG. 4 presents a z-plane representation of a representative filter stage of FIG. 3, each stage of the predictive filter element being implemented as a second-order filter. FIG. 5 is a chart illustrating the improvement in the dynamic range and detection bandwidth obtained by increasing the predictive filter order from one to two. FIG. 6 is a block diagram of the AGC loop. FIG. 7 illustrates the preferred implementation of the digital quadrature mixer of FIG. 1. FIG. 8 is a block diagram of the offset nuller loop. FIG. 9 is a block diagram illustrating a specific implementation of the present invention. FIG. 10 is a curve presenting measurements of the dynamic range achieved by the integrated circuit of the exemplary implementation example of FIG. 9 without the effect of the AGC loop. DETAILED DESCRIPTION OF THE INVENTION In most receiver designs, the received modulated signal is downconverted to an intermediate frequency (IF) and filtered to select the desired signal and reject the undesired adjacent signals and channel induced noise and interference. In modern receivers, the downconverted IF must be further downconverted to baseband and digitized, and then processed by a digital demodulator. The need to process the signal at baseband frequency is driven by the multiplicity of technical challenges caused by directly sampling the IF signal and the high processing throughput required to handle the resultant sampled IF. Recent advances in bandpass sampling have emerged. They introduce concepts of directly sampling the IF signal. These techniques use mostly analog circuits to achieve the conversion of the IF signal into the digital domain and as such tend to encounter several design implementation difficulties which, when avoided, results in a rather expensive implementation. This invention introduces a novel design implementation for an analog to digital converter which is capable of sampling and downconverting to baseband a modulated (IF) carrier. The Downconverting Digitizer covered by this invention achieves the following three processes: 1. Conversion of the modulated IF signal to the digital representation (i.e. digitization). 2. Downconversion of the modulated IF signal to a digital representation of the baseband in-phase (I) and quadrature (Q) components. 3. Automatic control of the processed modulated IF signal amplitude to extend the dynamic range of the digitization process and minimize quantization noise. FIG. 1 is a block diagram of the Downconverting Digitizer of this invention which is comprised of the following elements: 1. a digitally-controlled variable gain amplifier (200) which adjusts the amplitude of the modulated IF input signal (100) in accordance with the control signal (310) generated by the gain control logic (300). 2. a gain control logic element (300) which converts the predictive filter output signal (410) into a control signal (310) that is used to set the gain value of the variable gain amplifier (200). 3. an analog summing element (500) which generates the error signal (510) by combining the amplifier output signal (210) with the output of the digital summing element (1200) after being converted to analog representation by the digital-to-analog converter (DAC) (700). 4. a sampling element (800) which converts the analog error signal (510) into a digital representation (810). 5. a predictive digital filter (400) which utilizes an aliased component of the sampled error signal (810) to construct a digitally represented prediction of the modulated IF input signal (100). 6. an offset nuller element (600) which computes offset values due to implementation and provides a correction signal to the digital summing element (1200). 7. a digital summing element (1200) which sums the inverse of the offset correction signal (610) to the predictive filter output (410) to provide the DAC input signal (1210). 8. a digital to analog converter (DAC) element (700) which converts the digital output (1210) of the digital summing element (1200) to the analog representation (710). 9. a digital quadrature mixer (900) which mixes the output of the predictive filter (410) to baseband in-phase (I) (910) and quadrature (Q) (920) digital components. 10. two rate reduction filters (1000, 1100) for in-phase (I) (910) and quadrature (Q) (920) baseband outputs which are used to: (a) filter out the undesired alias components; and (b) reduce the sampling rate to be commensurate with the modulated signal bandwidth. The overall Downconverting Digitizer has an analog section, a digital section, and a mixed-signal section. In this invention, the analog section is minimized to allow maximum use of the flexibility offered by digital signal processing techniques. The analog section of the Downconverting Digitizer of FIG. 1 is comprised the variable gain amplifier (200) and the analog summing node (500). The feedback DAC (700) and the sampler (800) are the mixed-signal elements whose function is to transform the signal from the digital to the analog domain in the feedback path, and from the analog to the digital domain in the feedforward path, respectively. All of the remaining elements of the Downconverting Digitizer are implemented using digital hardware and operate at the rate of the sampling clock (50). The operation of the Downconverting Digitizer of this invention can be best described in terms of the operation of three loops, each comprised of a group of the aforementioned elements. First, the predictive loop, comprised of the summer (500), the sampler (800), the predictive filter (400), the digital summing element (1200), and the feedback DAC (700). Second, the offset nulling loop comprised of the offset nuller element (600), the digital summing element (1200), the DAC (700), the analog summing element (500), and the sampler (800). Finally, the automatic gain control (AGC) loop, comprised of the AGC control logic (300), the variable gain amplifier (200), the analog summing element (500), the sampler (800), and the predictive filter (400). The Downconverting Digitizer output signals (1010 and 1110) are multiple-bit digital representations of the baseband in-phase (I) and quadrature (Q) components, respectively, of the modulation. These output signals are normally routed to a digital demodulator portion of the receiver for detection and retrieval of the modulated information. The underlying principle of the Downconverting Digitizer of this invention is that of the characteristic of the predictive loop. The aforementioned loop generates a prediction (710) of the input signal (100). When the prediction (710) is subtracted at the summer (500), a prediction error signal (510) is generated. In the steady-state mode of operation, this predictive loop minimizes the prediction error signal (510). When this is accomplished, the output of the predictive filter (400) is a digital representation of the analog modulated input signal (100). Minimization of the loop error signal is achieved by placing the maximum frequency response of the predictive filter at the frequency of the modulated carrier after being sampled by the sampler (800). Based on this principle, the sampler (800) plays a critical role in the operation of the Downconverting Digitizer. Since the operation of the Downconverting Digitizer is based on minimizing the prediction error signal (510) in the steady-state, this error signal is nominally driven to zero. Due to implementation imperfection, certain offsets are generated. These offsets cause the error signal to deviate from its zero nominal value. The offset nulling loop is designed to generate an estimate of these offsets and eliminate them from the error signal. Successful conversion of the analog input signal (100) to a digital representation is critically dependent on the dynamic range of the Downconverting Digitizer. Since the Downconverting Digiziter operates on the principle of generating a digital prediction of the input signal (100) through the feedback path signal (410), this prediction is best suited to be used to generate a metric which sets the AGC amplifier (200) to the appropriate gain value. The purpose of the AGC loop is to maintain the amplitude of the modulated carrier (100) at a level within the dynamic range of the predictive loop. Sampler Element (800) Since the Downconverting Digitizer of this invention operates on the principle of sampling the minimized prediction loop error signal, this error signal can be sufficiently represented by one bit, hence allowing a low-cost implementation of the sampler as a 1-bit analog-to-digital converter (ADC) consisting of a limiter amplifier (840) and a `D` flip-flop (850) as shown in FIG. 2. In general, any specific application of this invention can be implemented with a multiple bit sampler. However, the description of the Downconverting Digitizer implementation using a 1-bit sampler is used as the basis of the description of the preferred embodiment henceforth, since it results in the lowest cost implementation. Within the context of this invention, the sampler element converts the loop error signal from an analog to a digital representation. As a consequence of this sampling process, the sampler output signal (810) contains alias components of the loop error signal (510). The predictive structure of this invention utilizes the lowest alias component, denoted f a , of the modulated carrier (100). The relationship between the modulated IF carrier (100) frequency f c , the sampling clock (50) frequency f s , and the alias component f a are: f.sub.c =[m+n]f.sub.s, and (1 alias component f a =n f s where m is an integer, and n is a fraction such that -1/2n≦1/2. When n±1/4, the implementation complexities of the predictive filter (400) and the digital quadrature mixer (900) are greatly reduced. The limiter amplifier (840) produces a bi-state continuous time signal (841) which the `D` flip-flop converts to a digital sample at the clock edge. In the sampler design shown in FIG. 2, the 1-bit ADC (830) is implemented as a high-gain amplifier (840) designed to limit when the magnitude of the error signal (510) is larger than one-half the magnitude of the least significant bit (LSB) of the feedback DAC (700). The output of the high-gain amplifier (841) is then sampled by a `D` flip-flop (850) at the clock edge. This flip-flop has input thresholds such that when the amplifier output (841) is above the middle of its voltage range, it is interpreted to be a digital logic "1", and when the amplifier output (841) is below the middle of the voltage range, it is interpreted to be a digital logic "0". Depending upon the gain-bandwidth characteristics of the semiconductor process used to implement the 1-bit ADC, it may be necessary to precede the limiter amplifier (840) in FIG. 2 with a Track-And-Hold circuit. The Track-And-Hold circuit, when operating at the sampling frequency f s , effectively presents the limiter amplifier with an alias component at the lower frequency f a which is within the gain-bandwidth range of the semiconductor process used to implement the limiter amplifier (840). The designer of the 1-bit ADC should perform the trade off analysis to determine the need of the Track-And-Hold circuit depending upon the center frequency of the IF, the sampling clock frequency (f s ), and gain-bandwidth characteristics of the semiconductor process used to implement the 1-bit ADC. Predictive Filter Element (400) The predictive filter (400) plays a central role in the operation of this invention. Having converted the error signal (510) from its continuous-time analog representation to its sampled digital representation using the 1-bit sampler (800), the predictive filter element of the loop is implemented using digital signal processing techniques. The predictive filter element is designed to generate a prediction of the modulated IF (100) at the next sampling epoch. In the context of this invention, this is achieved by placing the poles of the predictive filter (400) to coincide in the frequency domain with the center frequency of the alias component (f a ) of the modulated IF (100) after being sampled by the sampler (800). The underlying requirement for generating a valid prediction of the modulated IF (210) at the next sampling epoch is that the bandwidth of the modulation (W) be appreciably smaller than the clock rate (f s ) which in turn is related to the carrier frequency according to the following: W<<f.sub.c =[m+n]f.sub.s (2 where m is an integer, and n is a fraction such that -1/2≦n≦1/2. As previously stated, when n=±1/4 the implementation complexity of the predictive filter (400) and the digital quadrature mixer (900) is greatly reduced. Although the implementation of the Downconverting Digitizer of this invention is valid for any integer value m, selection of m≧2 allows the sampling clock frequency (50) to be selected at a value below the IF center frequency f c . Such a selection greatly simplifies the implementation of the design of the Downconverting Digitizer, and allows it to be used for digitizing higher frequency IF signals than otherwise possible. This provides the benefits of allowing the digital portion of the Downconverting Digitizer to operate at a lower clock frequency f s (50) while maintaining a high IF center frequency f c . A lower clock frequency f s (50) results in lower power consumption and lower cost and complexity for the digital hardware of the Downconverting Digitizer. A higher IF f c reduces the cost and complexity of the radio frequency components preceding the Downconverting Digitizer. This permits the system designer to minimize the overall cost and complexity of the system by selecting the IF center frequency at a value that achieves the lowest cost radio design while simultaneously selecting the sampling frequency at a value that achieves the lowest cost digital hardware design. A generalized structure of the predictive filter element (400) is shown in FIG. 3. The predictive filter element structure is a cascade of filter stages whose z-plane transfer functions are denoted by A k (z), k=0 to K-1, where K denotes the order of the predictive filter element. The output of each stage is weighted by a gain factor a k prior to being summed to generate the output of the predictive filter. As shown in the representative filter stage of FIG. 3, each stage of the predictive filter element is implemented as a second-order filter whose complex pole pair are located in the z-plane as shown in FIG. 4. Adjusting the filter coefficient (b 1 ) k varies the angle between the positive real axis and the radius to the pole. This determines the resonant frequency (f 0 ) k of the filter stage. Adjusting the filter coefficient (b 2 ) k varies the radial distance of the pole pair relative to the origin of the z-plane. This determines the 3-dB bandwidth (BW 3dB ) k of the filter stage. These relationships are defined by the following Equations (3). The Q-value of the k-th filter stage is expressed as: ##EQU1## The locations of the poles determine the frequency response of the predictive filter (400). The maximum frequency response of the predictive filter stage is placed at or near the center frequency of the sampled, modulated IF (f a ). The exact location of the poles is determined by the characteristics of the signal of interest. Because the predictive filter element (400) is implemented utilizing digital signal processing techniques, poles can be placed to achieve best performance. Such pole placement may not be possible for an analog implementation because component variations due to temperature, process, aging, etc. may result in filter instability. Furthermore, the digital implementation allows the filter response to be reprogrammed by changing the filter coefficients, hence allowing the predictive filter characteristics to be matched to the input signal (100). One of the main advantages that can be realized by this invention is that the predictive filter (400) is implemented as a digital filter. Unlike analog designs, the filter frequency response is impervious to performance variations due to process, temperature and aging. In addition, the predictive filter response can be reprogrammed to match the modulated IF (100). Within the context of this invention, the following parameters of the generalized predictive structure of FIG. 3 can be reprogrammed: K=the number of filter stages a k =the weighting gain for each stage (f 0 ) k =the center frequency of each filter stage (BW 3dB )=the bandwidth of each filter stage By reprogramming these parameters, the frequency response of the predictive loop of this invention can be changed. This can be done upon initialization or dynamically through the use of an external algorithm which derives the values of these settings by implementing the relationship stated in Equations (2). Conventional, broadband analog-to-digital converters add quantization noise to the digital representation of the signal which extends over the entire Nyquist bandwidth of the sampled signal from 0 Hz to f s /2. The digital predictive loop of this invention, on the other hand, has the inherent advantage of confining the quantization noise to a narrower bandwidth. This noise typically occupies a bandwidth much less than the Nyquist bandwidth. Such reduction in the broadband noise of the digital process following the predictive loop eases the design constraints placed on subsequent digital signal processing elements. This narrowband noise attribute is maintained during dynamic frequency response adjustments mentioned earlier. The dynamic frequency response adjustment feature of this invention is useful in many applications. As an example, by tracking the instantaneous carrier frequency of the modulated IF (100) using an external algorithm, the computational algorithm outlined in Equation (3) can be used to dynamically adjust the coefficients (b 1 ) k and (b 2 ) k of the predictive filter such that the center frequency of the predictive filter stages (f 0 ) k tracks the carrier frequency as that frequency changes due to Doppler, transmitter/receiver oscillator drift, etc. This allows the Downconverting Digitizer to maintain a high signal-to-quantization noise ratio of the digital representation (410) of the modulated IF (100). Another application of dynamic frequency response adjustment feature of this invention is that it can be used to reduce the distortion caused by interfering signals in a multi-channel receiver application such as cellular telephony. In the presence of interference, an external algorithm can adjust the predictive filter parameters to allow to better predict the interfering signals, thereby allowing these signals to be removed through subsequent digital filtering without undo distortion to the signal of interest. Such an external algorithm can derive a metric of the adjacent channel interference level by comparing the signal power at the output of consecutive stages of the predictive filter structure (400). When this comparison indicates the presence of a strong adjacent channel interference, the predictive filter coefficients (b 1 ) k and (b 2 ) k are dynamically adjusted using the computational algorithm of Equation (3) to increase the effective bandwidth (BW 3dB ) k of the predictive filter stages. Increasing the effective bandwidth of the predictive filter prevents undesired effects which could be caused by the presence of a strong adjacent channel interference, such as slope overload and intermodulation effects. Thus, by allowing the capability for dynamic adjustment of the frequency response of the predictive digital filter, the Downconverting Digitizer of this invention can be designed to dynamically respond to an infrequent increase in the adjacent channel interference while maintaining higher dynamic range when such an interference is within nominal level. An added benefit of the digital implementation of the predictive filter (400) is the word length expansion. In other words, the input samples to the predictive filter (810) can consist of 1-bit of quantized signal while the output samples of the predictive filter (410) consist of multiple bits. By allowing the sampler to be implemented as a 1-bit sampler, this invention realizes reduction in implementation cost by simplifying the sampling element without sacrificing performance. In addition, this word length expansion feature of the predictive filter (400) increases the precision of the digital representation (410). Dynamic range of signals in digital signal processing systems is determined by the number of bits in the digital representation. Each additional bit provides approximately 6 dB of additional dynamic range. The predictive filter (400) produces word length expansion, resulting in high dynamic range in the digital representation of the signal (410). The dynamic range of the invention is determined in part by the number of bits used out of the predictive filter for the feedback signal (410) input to the DAC (700). The determination of this number of bits is based on the following factors: (1) the implementation cost of the feedback DAC (700); (2) the dynamic range requirement; and (3) the complexity of the predictive filter (400). FIG. 5 illustrates the improvement in the dynamic range and detection bandwidth obtained by increasing the predictive filter (400) order from one to two. This improvement is achieved by reshaping the power spectral density of the quantized error signal (810). These plots show the power spectral density of the sampler output when the input to the predictive loop consists of additive white Gaussian noise (AWGN) with root mean square (rms) value equal to an LSB (Δ) of the feedback DAC (700). The power spectral plots show that the quantization noise is at a lower level for a broader range of frequencies in the sampling bandwidth using a second order predictive filter. The higher order predictive filter allows the loop to push more noise out of the bandwidth of interest, thus creating a notch in the quantized error signal spectrum. The second order predictive filter causes a larger notch to develop. The size and shape of the notch determines the degree to which the loop minimizes quantization noise of the sampled signal about the center frequency f a . This is an indication of how well the predictive filter (400) is at estimating the signal at the next sampling epoch. The predictive filter element (400) performs two functions within the loop. First it creates an estimate of the input signal (100) at the next sampling epoch. Secondly, the predictive filter element (400) filters out the quantization noise while increasing the word length of the digital representation of the signal (410). It is this second function of the predictive loop that lowers the noise bandwidth of the output signal. Conventional analog-to-digital converters inject quantization noise (σ 2 e ) with a power of ##EQU2## Thermal noise present at the input to the conventional ADC gets sampled and output. The Downconverting Digitizer generates its output by passing the sampled signal (810) through the predictive filter (400), which is a narrowband bandpass filter tailored to the signal of interest. Thus noise components outside the band containing the desired signal undergo significant attenuation in the predictive filter. (Additional out of band filtering is provided by the rate reduction filters (1000, 1100).) Since the predictive filter increases the word length of the sampled signal, the magnitude of the LSB of the signal representation is reduced and therefore the quantization noise power is reduced (from equation 4). In addition, with a specific selection of the predictive filter poles, the overall predictive loop can be made to further reduce the thermal input noise and quantization noise outside the vicinity of the modulated signal bandwidth. This noise shaping characteristic requires that the poles of the predictive filter be located at the inside of the z-plane unit circle. Analog-to-digital converters typically trade dynamic range for detection bandwidth. The dynamic range of the Downconverting Digitizer of this invention is determined by the depth of the notch above the point at which the width of the notch equals the signal bandwidth. Increasing the order of the predictive filter (400) both deepens and widens the notch in the quantized error signal spectrum. The second order predictive filter thus provides significant performance improvement over a first order predictive filter. The deeper notch provided by the second order predictive filter achieves a greater dynamic range. The wider notch allows signals with wider bandwidths to be represented with higher accuracy and more precision. Since the predictive filter output (410) of this invention has a high dynamic range, the DAC (700) must support the same dynamic range. Fast and wide dynamic range DACs are economical to implement, much more so than a similar size and speed traditional analog-to-digital converter. In effect, this invention utilizes the high dynamic range DACs with low implementation complexity and cost as an element in the implementation of high dynamic range, broad detection bandwidth analog-to-digital converters. In considering the die size of a hardware implementation, the use of a digital predictive filter (400) and a multi-bit DAC (700) offers several advantages compared with other oversampling implementations. For example, typical implementations of oversampled analog-to-digital converters utilize switched-capacitors to implement filtering and signal summing or subtracting functions. Those approaches require that substantial die area be utilized to implement the switched capacitors. In contrast, the DAC (700) of this invention can be implemented in a fraction of the die area used for the switched-capacitor structures of comparable oversampled converters. Furthermore, the digital implementation of the predictive structures can be implemented using minimum feature size transistors, and consequently the digital logic implementing the predictive filter (400) occupies very little die area. Further reduction in implementation cost of this invention is obtained by selecting the frequency of the sampled modulated carrier (f a ) to be f s /4. The selection of the center frequencies of the predictive filter stages (f 0 ) k equal to f a =f s /4 greatly simplifies the implementation by creating trivial gain values in the predictive filter. This is illustrated in the implementation example presented later. Digital-to-Analog Converter (DAC) (700) This element converts the digitally-represented sum (1210) of the predictive filter output (410) and the offset nuller correction signal (610) to an analog representation (710). The number of bits of the DAC (700) is chosen to be sufficient to ensure that the quantization noise introduced by the DAC (700) is below the quantization noise and prediction noise of the predictive filter (400) preceding the DAC. Digital Summing Element (1200) The digital summing element (1200) sums the offset nulling correction signal (610) to the predictive filter output (410) providing the DAC input signal (1210). Analog Summing Element (500) The analog summing element generates the error signal (510) by adding the analog representation of the prediction signal (710) to the amplified, modulated IF signal (210). The total delay around the predictive loop is maintained at two clock epochs. The effect of this delay, when combined with the selection f a =f s /4, results in a sign inversion of the feedback signal (710). This allows the negative feedback to be realized by simply adding the signal (710) to the signal (210) at the analog summing node (500). Automatic Gain Control Logic (300) Receiver dynamic range requirements are typically much larger than what can be achieved by the analog-to-digital converter alone. The dynamic range of the received signal is driven by two contributing factors. First, a rapidly varying component that contains the modulated information. This component of the dynamic range is referred to as the instantaneous dynamic range. Second, there is a slowly varying component due to external effects that carries no useful information regarding the modulated information. The receiver must have sufficient dynamic range to support both of these components. The dynamic range provided by the predictive loop of this invention can be designed to be equal to or greater than the entire dynamic range of the received signal. However, a more cost effective approach can be achieved by utilizing the fact that the received signal dynamic range partially consists of a slowly varying component, which contains no information regarding the modulation. That component can be removed with an automatic gain control (AGC) loop prior to the predictive loop. Since the predictive filter output (410) is a digital prediction of the modulated carrier (100) to the input of the Downconverting Digitizer, this signal is ideal for controlling the AGC. The purpose of the AGC loop is to maintain the magnitude of the modulated IF (100) at a level within the dynamic range of the predictive loop. A block diagram of the AGC loop is shown in FIG. 6. The AGC loop is comprised of the AGC control logic (300), the variable gain amplifier (200), the analog summing element (500), the sampling element (800), and the predictive filter (400). The AGC control logic element (300) consists of the power detector (320), the summing node (330), the AGC loop gain element (340), the AGC loop filter (350), and the gain control encoder (360). The power detector (320) provides an estimate of the power of the predictive filter output (410). The AGC loop operates with any monotonic function of the signal level including power or magnitude. The output of the power detector (321) is compared to the externally provided AGC level set point control (370) to generate an AGC gain adjustment signal (331). The AGC level set point control (370) adjusts the AGC output level (210). The AGC control logic (300) sets the AGC (200) gain such that the signal level at the amplifier output (210) is commensurate with that of AGC level set point control (370). The inputs to the AGC control logic (300) are the predictive filter output (410) and the AGC level set point control (370). The AGC gain adjustment signal (331) is amplified by the AGC loop gain element (340). The gain applied by the AGC loop gain element (340) determines the loop settling time. The amplified gain adjustment signal is filtered by the AGC loop filter (350). Since the AGC loop is designed to respond to slow variation in the signal dynamics, the AGC loop filter (350) reduces the rate of the power detector output (320) by averaging the value of this output. The encoder (310) is an element which converts the loop filter output (341) to the proper format to control the variable gain amplifier (200). Variable Gain Amplifier (200) The variable gain amplifier(200) applies gain to the received signal (100) as a function of the AGC control logic output (310). The variable gain amplifier (200) has sufficient controllable gain to entirely remove the slowly varying component of dynamic range of the received signal (100). Offset Nuller (600) All analog-to-digital converters suffer some performance degradation due to internally and externally generated offsets that result in deviation of the digitized output from the ideal. These offsets can result from component variations due to process, temperature and aging as well as aliasing of sample clock harmonics added to the input signal via undesired analog coupling. These offsets tend to be difficult to detect and remove. An advantage of the Downconverting Digitizer of this invention is the integrated offset nuller element (600) that automatically and dynamically detects and removes offsets that would otherwise impair the analog-to-digital conversion. Conventional implementations of analog-to-digital converters cannot dynamically remove the effects of offset error. Typical analog-to-digital converters require a manual calibration or a calibration mode that requires the converter to be off-line during calibration. These types of calibration are non-dynamic, and as such, are susceptible to temperature and aging effects and may ultimately result in some performance degradation due to offset. The offset nuller element (600) of the Downconverting Digitizer dynamically determines offset during operation, thereby requiring no manual calibration of off-line mode. During the analog-to-digital conversion process, the offset nuller continuously estimates the size of the offset and removes it. A block diagram of the offset nuller loop is shown in FIG. 8. The offset nuller loop consists of the offset nuller element (600), the digital summing element (1200), the DAC (700), the analog summing element (500), and the sampler (800). Because the predictive loop operation drives the loop error signal (510) to zero, in the absence of an offset, the average of the values output from the sampler (800) should be zero. If an offset is present, the average value of the sampler output is proportional to that offset. The offset nuller (600) averages the sampler output to determine the offset correction signal (610). The nuller loop filter (620) computes the average of the sampler output (800). The estimated offset value is then amplified by the digital gain (630) and then combined with the predictive filter output to generate the feedback signal (1210). Digital Ouadrature Mixer (DOM) (900) The function of the DQM (900) is to downconvert the output of the predictive filter (400), which has a center frequency f a , to baseband in-phase (I) and quadrature (Q) components. Conventionally, this downconversion to baseband requires multiplying the signal centered around the frequency f a by sin(f a ) and cos(f a ) to generate the (I) and (Q) components, respectively. Since, in this invention, f a is selected to be equal to f s /4, the values of sin(f a ) and cos(f a ) computed at the epoch of the clock f s are simply {0, 1, 0, -1} over one cycle of f a . Hence, the selection of f a =f s /4 offered by this invention allows a significant reduction in the implementation of the DQM element (900). As shown in FIG. 7, the implementation of the DQM is a simple circuit which routes alternate output samples of the predictive filter to either the in-phase (I) (910) or quadrature (Q) (920) outputs. Each of these two outputs I and Q are then alternately inverted to generate the final in-phase (I) and quadrature (Q) output samples. Rate Reduction Filter (1000, 1100) The rate reduction filters (1000) and (1100) perform two functions: filtering and sample rate reduction of the inphase (I) and quadrature (Q) components. The rate reduction filters (1000), (1100) are designed to reject the double frequency term (2* f a ) generated in the DQM (900). In addition, the rate reduction operations filter the input signal to prevent aliasing due to sample rate reduction. The filtering performed by the rate reduction filters is significantly greater than required to prevent aliasing. These digital filters are designed to pass the signals of interest without attenuation. Undesired signals outside of the band of interest are attenuated. This attenuation provides the Downconverting Digitizer with the feature of producing a sampled signal with lower noise bandwidth than the input signal. Sample rate reduction is performed to reduce the processing rate of the digitized signal. The implementation of each rate reduction filter (1000 and 1100) is identical. Since they are implemented digitally, the in-phase (I) (1010) and quadrature (Q) (1110) signals of the output of the Downconverting Digitizer do not undergo losses due to gain and phase imbalance that typically accompany analog implementations. Implementation Example The Downconverting Digitizer of this invention was implemented and verified as part of a wireless telephone receiver. The semiconductor process for this design was CMOS, 0.6 micron, 2-poly, 3-metal. The overall circuit was incorporated with other functions on a mixed signal CMOS integrated circuit and verified to meet the design specification required for the operation of the wireless telephone receiver. The details of the circuit implementation are shown in FIG. 9. In the implementation example shown in FIG. 9, the modulated IF is centered at f c =82.8 MHz with a two-sided bandwidth of 30 kHz. For this particular design, the sample rate (f s ) was chosen to be 14.4 MHz. This results in spectrally inverted f a at 3.6 MHz. This corresponds to the following parameters in Equation 1. ##EQU3## The negative sign indicates spectral inversion. In performing the design tradeoff analysis of the gain bandwidth characteristics of the selected semiconductor process and the frequency of the IF and the sampling clock frequency, it was determined that a track-and-hold circuit was required in the sampler. The sampler (2800) is implemented as a track-and-hold element, followed by a limiter and a `D` flip flop as shown in FIG. 9. The track-and-hold element is used because the CMOS implementation of the limiter does not have sufficient gain-bandwidth at f c =82.8 MHz to allow the limiter to settle to a bi-state level at the next sampling epoch. The track-and-hold creates an alias frequency at f a , which the limiter can drive to a bi-state value for conversion to a digital format by the `D` flip-flop. The coefficients of the predictive filter structure (2410) shown in FIG. 9 are: a.sub.1 =a.sub.2 =1 (b.sub.1).sub.1 =(b.sub.1).sub.2 =0 (b.sub.2).sub.1 =(b.sub.2).sub.2 =1 In this implementation, delay around the predictive loop from the error signal (2510) to the analog representation of the predictive filter output (2710) is two clock epochs. As a result, the DAC output (2710) is added in the summer element (2500) to the modulated carrier (2100), rather than subtracted from it. Based on analysis of the required dynamic range of the overall Downconverting Digitizer, the DAC (2700) is designed as a 9-bit DAC. The 9-bit DAC (2700) has a maximum peak-to-peak output voltage of 250 mV. The DAC (700) is designed to have a settling time sufficiently small to ensure that the error signal (2510) settles in time for an accurate conversion by the 1-bit ADC (2800). The output of the offset nulling element (2610) is added digitally to the output of the predictive filter. The DAC output is then added to the analog amplified, modulated IF (2210). The combined output of the predictive filter and the offset nuller is converted to an analog representation using the 9-bit DAC. The summing element generates the error signal (2510) by adding the analog representations of the nulling signal and the prediction signal (2710) to the amplified, modulated IF (2210). The AGC control logic (2300) is designed to control a multi-stage amplifier (2200). The total gain realized by the multi-stage implementation of the variable gain amplifier (2200) has a maximum value of 71 dB and a minimum value of -1 dB. Each stage of the multi-stage amplifier is digitally-controlled and has two nominal gain values. The nominal gain value of each stage is selected using one bit of the digital control logic output (2310). The gain stages of this variable gain amplifier are controlled according to the following relationships: ______________________________________Gain Stage Type Digital `1` Digital `0`______________________________________Course 7.0 dB -3.0 dBMedium 4.0 dB 0 dBFine 3 0 dB -2.0 dBFine 2 0 dB -1.0 dBFine 1 0 dB -0.5 dBFine 0 0 dB -0.25 dB______________________________________ The DQM is implemented as shown in FIG. 8. The rate reduction filters are implemented as a cascade of three comb filters. The output of the rate reduction is decimated to 160 ksps. After rate reduction, these samples are truncated to 10-bits each. Measurements of the dynamic range achieved by the integrated circuit of this implementation example of FIG. 9 are shown in FIG. 10 without the effect of the AGC loop. As shown in this figure, the implemented Downconverting Digitizer provides more than 52 dB of dynamic range. This is equivalent to the dynamic range performance provided by a dual 8-bit baseband analog-to-digital converter while simultaneously performing the downconversion from IF to baseband with reduced noise performance. The designed AGC loop extends this dynamic range to more than 124 dB. While preferred embodiments of the present invention have been disclosed and described herein, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention.

A simple down converting A/D converter utilizing predictive coding principles. By placing the sampler inside the predictive loop, the predictive loop filter can be implemented using DSP techniques, thus eliminating the complexities introduced by use of discrete-time analog circuitry. Then, by re-mapping the output of the predictive loop filter into the analog domain using a D/A converter, the predictive filter output signal is subtracted from the input analog signal to generate the prediction error signal. Therefore, through directly sampling the prediction error signal and converting the output of the predictive loop filter into analog representation using a low-cost multiple bit D/A, the use of discrete-time analog circuitry is eliminated and the complexity of the converter design is greatly reduced. Various features of the invention are disclosed.

big_patent

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates generally to active solid state devices, specifically to apparatus and method for making and using sensors with nanodimensional features that are responsive to molecular compounds, organisms or gas molecules. [0003] 2. Description of Related Art [0004] The use of nanowires and nanotubes for label-free direct real-time detection of biomolecule binding is known in the art. Nanowires and nanotubes have the potential for very high-sensitivity detection since the depletion or accumulation of charge carriers, which is caused by binding of a charged biological macromolecules at the surface, can affect the entire cross-sectional conduction pathway of these nanostructures. See, e.g., Direct Ultrasensitive Electrical Detection of DNA and DNA Sequence Variations Using Nanowire Nanosensors, by Jong-in Hahm and Charles M. Lieber, Nano Letters, 2004 (Vol. 4, No. 1 pp. 51-54), which is incorporated by reference (hereinafter Lieber). Lieber discloses measurable conductance changes associated with hybridization of a Peptide Nucleic Acid (PNA) receptor with complimentary Deoxyribose Nucleic Acid (DNA) target molecule. A practitioner skilled in the art will appreciate that a Peptide Nucleic Acid (PNA) receptor could be substituted with a Deoxyribose Nucleic Acid (DNA) receptor or a Ribose Nucleic Acid (RNA) receptor. [0005] U.S. Pat. No. 7,301,199 discloses nanowires fabricated using laser catalytic growth (LCG), and is incorporated by reference in its entirety. In LCG, a nanoparticle catalyst is used during the growth of the nanoscale wire. Laser vaporization of a composite target composed of a desired material and a catalytic material creates a hot, dense vapor. The vapor condenses into liquid nanoclusters through collision with a buffer gas. Growth begins when the liquid nanoclusters become supersaturated with the desired phase and can continue as long as reactant is available. Growth terminates when the nanoscale wire passes out of the hot reaction zone or when the temperature is decreased. In LCG, vapor phase semiconductor reactants required for nanoscale wire growth may be produced by laser ablation of solid targets, vapor-phase molecular species, or the like. To create a single junction within a nanoscale wire, the addition of the first reactant may be stopped during growth, and then a second reactant may be introduced for the remainder of the synthesis. Repeated modulation of the reactants during growth is also contemplated, which may produce nanoscale wire superlattices. LCG also may require a nanocluster catalyst suitable for growth of the different superlattice components; for example, a gold nanocluster catalyst can be used in a wide-range of III-V and IV materials. Nearly monodisperse metal nanoclusters may be used to control the diameter, and, through growth time, the length of various semiconductor nanoscale wires. This method of fabricating nanowires is known in the art, and constitutes one method of creating nano-scale features. [0006] The use of photolithography for fabrication of micron-scale features is well known in the art. In “standard” photolithography, multiple steps are performed to pattern features on a surface. In the initial step, the surface, which may be a p- or n-doped silicon wafer, is cleaned of surface contaminants. Persons skilled in the art will appreciate that many planar surfaces can be patterned in this way, including surfaces with multiple layers, such as a substrate of p- or n-doped silicon, a middle layer of insulating silicon dioxide (SiO 2 ), with a top layer of metal. Next, adhesion promoters are added to the surface to assist in photoresist coating. Photoresist may be spin-coated onto the surface, forming a uniform thickness. The wafer containing the photoresist layer is then exposed to heat to drive off solvent present from the coating process. Next, a photomask, which may be made of glass with a chromium coating, is prepared. The features desired on the surface of the wafer are patterned on the photomask. The photomask is then carefully aligned with the wafer. The photomask is exposed to light, the transparent areas of the photomask allow light to transfer to the photoresist, the photoresist reacts to the light, and a latent image is created in the photoresist. The photoresist may be either positive or negative tone photoresist. If it is negative tone photoresist, it is photopolymerized where exposed and rendered insoluble to the developer solution. If it is positive tone photoresist, exposure decomposes a development inhibitor and developer solution only dissolves photoresist in the exposed areas. Simple organic solvents are sufficient to remove undeveloped photoresist. The techniques of “etch-back” and “lift-off” patterning are used at this stage. If the “etch-back” technique is used, the photoresist is deposited over the layer to be pattered, the photoresist is patterned, and the unpatterned areas of the layer are removed by etching. If the “lift-off” technique is used, photoresist is deposited followed by deposition of a thin film of desired material. After exposure, undeveloped photoresist is removed by the developer solvent and carries away the material above it into solution leaving behind the patterned features of the thin film on the surface. Removal of the remaining photoresist may be accomplished through oxygen plasma etching, sometimes called “ashing”, or by wet chemical means using a “piranha” (3:1 H 2 SO 4 :H 2 O 2 ) solution. [0007] Although widely used and extremely useful as a micron-scale patterning tool, “standard” photolithography is limited in the resolution of the features it can pattern. The ability to project a clear image of a small feature onto the wafer is limited by the wavelength of the light that is used, and the ability of the reduction lens system to capture enough diffraction orders from the illuminated mask. The minimum feature size that a projection system can print is given approximately by: CD=k 1 *(λ/NA); where CD is the minimum feature size (also called the critical dimension, target design rule); k 1 (commonly called k 1 factor) is a coefficient that encapsulates process-related factors, and typically equals 0.4 for production; λ is the wavelength of light used; and NA is the numerical aperture of the lens as seen from the wafer. According to this equation, minimum feature sizes can be decreased by decreasing the wavelength, and increasing the numerical aperture, i.e. making lenses larger and bringing them closer to the wafer. However, this design method runs into a competing constraint. In modern systems, the depth of focus (D F ) is also a concern: D F =k 2 *(λ/(NA) 2 ). Here, k 2 is another process-related coefficient. The depth of focus restricts the thickness of the photoresist and the depth of the topography on the wafer. One solution known in the art is utilization of light sources with shorter wavelengths (λ), and creation of lenses with higher numeric apertures (NA). The drawback to this solution is the increasingly prohibitive high cost of fabricating complex sources and optics. [0008] Nanoimprint Lithography (NIL) solves the problem of limited minimum feature sizes and high cost by patterning nano-scale features into a quartz plate, referred to as the “template” that can be applied directly to the surface of a wafer and transferring the pattern 1:1 into a photoresist layer. “Step and Flash Imprint Lithography,” by Resnick, D., et al., Solid State Technology , (2007), Feb., 39, which is incorporated in its entirety by reference, discloses the method to pattern nano-scale features by first imprinting the features into a photoresist layer and dry etching the imprint layer into the desired thin film layer on a wafer. The S-FIL process, now generally known in the art as Nanoimprint Lithography (NIL), requires that electron beam lithography be first used to “write” the desired imprint pattern into the template. The template may be a quartz plate substrate coated with a chromium (Cr) layer. The electron beam resist is patterned and the pattern is transferred into the Cr layer and the final three-dimensional relief structure is etched into the quartz plate or “template.” After transfer of the pattern into the quartz layer, the Cr layer is stripped, leaving an optically transparent template with the imprint pattern etched onto one surface. [0009] To create the imprint pattern into a thin film layer on a wafer substrate, a low-viscosity photocurable monomer—known as the etch barrier—is dispensed on its surface. The transparent template is brought into contact with the monomer at a slight angle, creating a monomer wavefront that spreads across the surface and fills the three dimensional relief structures of the transparent template. UV light photopolymerizes the monomer and the template is separated from the wafer, leaving a solid replica of the reverse of the template on the substrate surface. Post-processing consists of a breakthrough etch of the residual layer of the monomer, followed by a selective etch into an organic layer and finally transfer of the pattern into the desired layer; for example a semiconductor thin film. Imprint lithography has been used to create feature CDs on the order of 20 nm in high density over large areas, e.g. 4-6″ wafers during a single imprint process. [0010] In a similar fashion, the reverse process (S-FIL/R) can be accomplished. This is achieved by imprinting the surface using the template followed by spinning on an organic layer. The organic layer is etched back to expose the top surface of the silicon-containing imprint which is then selectively etched to the substrate using the organic layer as an etch stop. A final set of etching conditions is used to transfer the pattern into the substrate material. Nanoimprint Lithography has the advantage of being limited only by physical resolution of the template rather than being limited by wavelength and numeric aperture, as in standard photolithography. As new methods emerge for template fabrication, a corresponding increase in feature resolution can be expected. [0011] U.S. Pat. No. 6,426,184 discloses a method for massively parallel synthesis of DNA, RNA, and PNA molecules utilizing photogenerated reagents (PGR), and is incorporated herein by reference. The method involves a microfluidic chamber comprising a series of wells that act as reaction sites with a transparent sealed cover. Within each well, a “linker” molecule functionalized with a “reactive group” is attached to the substrate. The reactive group couples a “spacer group” which then couples the first nucleotide to the surface. The nucleotide bears a “protection group” initial. The reactive precursor to the PGR is introduced through the microfluidic chamber into the well sites. Selective wells receive light using a spatial light modulating device during a given exposure step which results in a “photogenerated reagent” within each well that was exposed. PGR is activated only in the wells that are exposed to light, thereby causing a chemical reaction with the protection group, and “de-protecting” the terminal nucleotide in the nucleic acid sequence. The PGR is flushed from the system, and a select nucleotide with a “protection group” is introduced. The nucleotide with “protection group” is covalently bonded to the end of the nucleic acid sequence in the selected wells. In all other wells that do not get exposed to light, no reaction takes place and no nucleotide coupling occurs during that exposure cycle. After proper washing, oxidation, and capping steps, the addition of the cycle is repeated in such a fashion to synthesize any combination of nucleotides onto surface-anchored nucleic acid sequences that are specific to each well. The process is continued until the oligonucleotides of interest are constructed over the entire array. The chemistry of building oligonucleotides is well known in the art. Because the sequence is known for each well in the multiplex detection array, diagnostic tests that result in a signal transduction event can be performed by first identifying if a reaction occurs for a given well, and second by determining the position, and hence identity of the “known” anchor probe sequence. [0012] “Light Directed Massively Parallel On-chip Synthesis of Peptide Arrays with t-Boc Chemistry,” by Gao, X., et al., Proteomics , (2003), 3, 2135 discloses PNA synthesis using t-Boc chemistry, and is incorporated by reference herein. This article is an example of chemical syntheses of anchor probe libraries known in the art. [0013] What is needed is a cost-effective, time-efficient, reproducible method for fabricating arrays of nano-scale features on a single wafer to form a sensor device or a matrix of devices for multiplex detection of selected analytes using many simultaneous detection zones, by detecting changes in electrical characteristics of the nano-scale materials for each device. Method for making such sensors and arrays is needed. SUMMARY OF INVENTION [0014] The problem of reproducibly fabricating semiconducting active layers that provide the necessary nano-dimensional features for direct electrical detection in sensing applications is solved using nanoimprint lithography to define groups of semiconducting nanotraces between electrodes. Such groups may be used as a sensor or, when anchored probe molecules are covalently coupled or synthesized to the surfaces, be used for multiplex detection of analytes. Nanoimprint lithography also provides a method to fabricate arrays of semiconducting electrode “nanotraces” in a controllable and regular pattern in a single processing step. A method that provides controlled fabrication of nanophase features provides a means for detection of gases adsorbed on the semiconductor surfaces or multiplex detection of many simultaneous detection zones. Binding of complementary targets to the anchored probe molecules in the vicinity of the semiconducting active layer produces a change in electrical conductivity of the semiconducting active layer that can be monitored externally for each sensor device in the array in parallel. BRIEF DESCRIPTION OF THE DRAWINGS [0015] FIG. 1 depicts a subset of the multiplex detection array showing six sensor devices with the imprinted semiconductor nanotraces. The inset shows the features of an individual semiconductor nanotrace in the set of nanotraces disposed between the electrodes. [0016] FIGS. 2 A-F illustrates the fabrication sequence for preparing the electrical base including the semiconductor nanotraces for the multiplex detection array. [0017] FIGS. 3 A-E illustrate the process of preparing the imprint pattern for the semiconductor nanotraces. [0018] FIGS. 4 A-E illustrate the process for etching the semiconductor nanotraces. [0019] FIG. 5 shows a high resolution SEM of the imprinted SFIL over the semiconductor active layer. [0020] FIGS. 6 A-B show a high resolution SEM of the transfer of the imprint pattern to form the semiconductor nanotraces. This image depicts nanotraces with transverse bridging segments. [0021] FIGS. 7 A-C show the multiplex detection device preparation steps for performing PGR in the preferred embodiment and packaging onto the electronics board. [0022] FIGS. 8 A-B show examples of the response generated during binding reactivity in the preferred embodiment. DETAILED DESCRIPTION [0023] FIG. 1 illustrates an overview of a subset of the electrical detection portion of multiplex detection array 101 , which consists of six individual sensor devices 102 A-F. A single sensor device, e.g. 102 A, is defined as a region that is independently electrically addressable from neighboring devices 102 B-F in FIG. 1 . Some of the features have been removed in this overview to enable a visual representation of the core components of multiplex detection array 101 . Each sensor device 102 consists of a set of two interdigitated electrodes including source electrode 103 , and drain electrode 104 of an individual sensor, e.g. sensor device 102 B. A third gate electrode 105 may be positioned to cross under the interdigitated portion of each column of sensor devices 102 , e.g. sensor devices 102 C and 102 F in FIG. 1 . Gate electrode 105 is in a lower plane than source 103 and drain 104 electrodes and is separated by thin oxide dielectric layer 106 supported by a suitable substrate wafer 107 , for example a silicon wafer or polymeric film. All of the electrodes 103 - 5 have relatively large scale features (˜1-5 μm) that are patterned using standard lithography. In this example, gate electrode 105 is common to each column of sensor devices 102 and terminates at gate electrode bonding pad 108 in an area remote from the sensor devices 102 . Similarly, source electrode 103 is common to all sensor devices 102 in each column in the array and terminates at source electrode bonding pad 109 in an area remote from sensor devices 102 and parallel with gate electrode 105 . Each of the drain electrodes 104 terminates at each sensor device 102 at drain electrode stub bonding pad 110 . A secondary process enables electrical continuity of drain electrode stub bonding pad 110 to be transferred to a higher plane that is separated by oxide insulating layer 111 . Electrical continuity is transferred by metal filling of drain electrode vias 112 that are positioned over each drain electrode stub bonding pad 110 and below each drain electrode pick-up pad 113 , which is in the higher plane. The portion of drain electrode 104 B in this plane is common for each row of sensor devices 102 ; for example, sensor devices 102 A-C and sensor devices 102 D-F in FIG. 1 , and terminates at drain electrode bonding pad 114 . Drain electrodes 104 B are perpendicular to the source 103 and gate 105 electrodes but in a different electrode plane to prevent shorting across the sensor devices 102 . [0024] In the center of each sensor device 102 is a set of parallel semiconductor “nanotraces” 115 that are perpendicular to and disposed across, the interdigitated finger region of the source 116 and drain 117 electrodes. Semiconductor nanotraces 115 can be fabricated using nanoimprint lithography. Each semiconductor nanotrace 118 , FIG. 1 inset, in the set of parallel nanotraces 115 provides a narrow electrical bridge between source 103 and drain 104 electrodes by making contact with the interdigitated finger region of each of the source 116 and drain 117 electroces. In the preferred embodiment ( FIG. 1 inset), the dimensions of individual nanotraces 118 range between 10 nm to about 100 nm in width 119 and depth 120 where the depth 120 is defined by the thickness of the originally deposited semiconducting active layer. More preferable, the width of each nanotrace is less than about 50 nm. Most preferable, the width of each nanotrace is less than about 20 nm. Pitch 121 between neighboring nanotraces 118 in the set of parallel nanotraces 115 can vary depending on the number of nanotraces 118 included in the set and the total surface area of the interdigitated finger region of source 116 and drain 117 electrodes. The number of nanotraces 118 can range from one to hundreds depending on the application. The length 122 of the semiconductor nanotraces 118 spans the full distance from the outside source interdigitated finger 116 to the outside drain interdigitated finger 117 of each sensor device 102 , crossing over all interdigitated fingers therebetween. [0025] When an external electric field is applied across drain electrode 103 and source electrode 104 , electrical current must travel through the set of parallel semiconductor nanotraces 115 to pass from the source electrode finger 116 to the drain electrode finger 117 . Because the width 119 of each semiconductor nanotrace 118 is on the order of the electrical diffusion pathway and the surface-to-volume ratio for each nanotrace 118 is large, the current traveling through each nanotrace 118 is highly influenced by its local environment 123 near the surface. The response is proportional to the degree in which the electrical current traversing the set of semiconductor nanotraces 115 is influenced by changes in the electric field strength near the surface of each nanotrace 118 . The local environment 123 can be a gas phase, e.g. an air plenum sampling for toxic gases, a solution environment e.g. and aqueous buffer sampling for complementary nucleic acids, or a solid environment e.g. an electrophoresis gel sampling for nucleotides on a nucleic acid sequence. The fabrication of a set of parallel nanotraces 115 serves to homogenize the total response to changes in local environment 123 since the total response is the average of the response of each nanotrace 118 connected in parallel between the interdigitated finger region of the source 116 and drain 117 electrodes. Averaging the response over a number of nanotraces 118 lowers the failure rate of sensor devices 102 during fabrication of the multiplex detection array 101 . Because each nanotrace 118 is in direct electrical contact with the interdigitated finger region of source 116 and drain 117 electrode, contact resistance 124 between the two materials must be kept low. The present embodiment depicted in FIG. 1 shows a bottom contact approach for forming the electrical interface between semiconductor nanotrace 118 and the interdigitated finger region of source 116 and drain 117 electrodes, however, alternate methods which include top contact between the interdigitated finger region of source 116 and drain 117 electrodes can be used to make the electrodes. Because semiconductor nanotraces 118 are electrically continuous with the interdigitated finger region of the source 116 and drain 117 electrodes that work back to the source 109 and drain 114 electrode bonding pads through source 103 and drain electrode 104 and 104 B, the source-to-drain current can be measured externally through electrodes that make contact with source 109 and drain 114 electrode bonding pads, Electrical continuity from the bonding pads to an electrode is established using common techniques such as wire or bump bonding of the multiplex detection array 101 chip to an electronics board package (not shown in FIG. 1 ). Method for Patterning the Base Electrode Structures: [0026] FIGS. 2A-F illustrate the series of fabrication steps for multiplex detection array 101 in preparation for binding of probe libraries specific to the type of test being performed. Initially, substrate 107 is used as a base for fabricating the array of sensor devices 102 , FIG. 2A . Suitable materials for substrate 107 include any semiconductor or insulating wafer such as glass, doped or undoped semiconductors e.g. silicon, or polymers. Substrates such as flexible polymer films or metal foils may also be used. A series of parallel, individually-addressable gate electrodes 105 are deposited on substrate 107 . If substrate 107 is semiconductor or electrically conducting, an insulating layer (not shown in FIG. 2 ) may be deposited prior to deposition of gate electrode 105 on substrate 107 to provide a means to prevent shorting of gate electrodes 105 to the substrate. A suitable material for gate electrodes 105 is a tie layer of chromium or titanium (˜5 nm) and a gold electrode layer (˜40-100 nm). A suitable means to deposit gate electrode layer 105 is vacuum deposition and a suitable means to subsequently pattern gate electrodes 105 is standard lithography. In the embodiment illustrated in FIG. 2A , each gate electrode 105 is common to an entire column of sensor devices that are subsequently deposited over gate electrode 105 . Each gate electrode 105 terminates at a gate electrode bonding pad 108 that are positioned in an area remote from any sensor devices 102 , depicted previously in FIG. 1 , to enable facile connection with an external set of electrodes. [0027] After patterning of gate electrodes 105 , gate dielectric layer 106 is deposited by chemical vapor deposition. The thickness of the gate dielectric layer 106 is a balance between maximizing the field effect from gate electrode 105 and preventing electrical breakdown at too high of an electrical field. A suitable material for gate dielectric 106 is silicon dioxide and the thickness preferably ranges between 10 nm and 200 nm. The need for gate electrode 105 is dependent on the application of the multiplex detection array 101 . As an alternative to that depicted in FIG. 2A , the gate electrode may be formed using standard ion implantation into substrate 107 , which is well known in the art. Another embodiment might include using the entire substrate 107 as a common gate electrode. This does not require deposition and patterning of the metal gate electrode 105 although gate dielectric 106 is always deposited. Similarly, in another embodiment, the need for gate electrode 105 might be removed altogether as the chemiresistive measurement of sensor devices 102 may occur without preconditioning of the electrical properties of semiconductor nanotraces 118 using the field from a gate electrode 105 . [0028] The example illustrated in FIG. 2B shows common gate electrode 105 positioned below the column of sensor devices 102 created by sensor devices 102 A and 102 D in multiplex detection array 101 . A continuous metallic layer is deposited over the surface of gate dielectric 106 . The electrode material is composed of a tie layer (˜5 nm of chromium or titanium) followed by a gold layer (˜40-100 nm). The electrode materials may be deposited by thermal evaporation, electron beam evaporation, or some suitable other process. After deposition, a photolithography processing step is performed using a standard photoresist layer that is exposed and developed to generate the gold features that compose segments of both the source 103 and drain 104 electrodes. As part of the pattern, the interdigitated finger region for both source 116 and drain 117 electrodes are developed in a single layer with source electrode fingers 116 contiguous with the common source electrode 103 . Source electrode 103 is also contiguous between the source side of each sensor device 102 for a given column. For example, the source electrode connects sensor devices 102 A and 102 D, 102 B and 102 E, and 102 C and 102 F in FIG. 2B . Each source electrode 103 terminates at a source electrode bonding pad 109 . The source electrodes 103 are parallel with the gate electrodes 105 and terminate in an area remote from the sensor devices 102 in the multiplex detection array 101 . The position of the source electrode bonding pads 109 is offset from the gate electrode bonding pads 108 to accommodate the necessary steps to liberate the gate dielectric 106 above the gate electrode bonding pads 108 . Removal of a portion of the gate dielectric layer is illustrated as the gate electrode window 201 in FIG. 2B . Grouping of the source electrode bonding pads 109 in this region provides a means for facile electrode connectivity to an external electronic board (not shown). [0029] The interdigitated fingers on the drain side 117 is contiguous with the first leg of drain electrode 104 which terminate with the drain electrode stub bonding pad 110 on each sensor device 102 . The drain electrode stub bonding pad 110 serves as a termination point for subsequent transfer of the drain electrical connection into a secondary electrode plane (described later). In addition to the deposition of the electrode structures 103 and 104 , alignment marks for aligning subsequent layers are also patterned into the gold electrode layer on the edges of multiplex detection array 101 that are not visible in FIG. 2 . Fabrication of the Semiconductor Nanotraces [0030] After fabrication of the base electrode layers, a semiconducting active layer is deposited over the entire wafer. Chemical vapor deposition, electron beam deposition or other suitable methods may be employed. Suitable materials for the semiconducting active layer are Group IV, III-V, and II-VI materials including tin oxide (SnO 2 ), indium oxide (In 2 O 3 ), and zinc oxide (ZnO) and other nitrides and chalcogenides. Using the method of nanoimprint lithography (NIL) and a series of dry etch processes, the semiconducting active layer is patterned into a set of parallel nanotraces 115 over the interdigitated finger region of the source 116 and drain 117 electrodes. A separate set of parallel nanotraces 115 are patterned over each sensor device 102 , FIG. 2C . Each nanotrace 118 in the set of nanotraces 115 is patterned such that the long axis of the nanotrace 122 runs parallel with the column of sensor devices 102 and perpendicular with the interdigitated finger region of the source 116 and drain 117 of the source 103 and drain 104 electrodes. [0031] Nanoimprint lithography is a special processing technique that enables nanodimension features to be patterned into the semiconducting active layer using a top down approach without the use of expensive stepper aligner tools. The dimensions of each semiconductor nanotrace 118 are critical for increasing the response sensitivity to a level that provides practical direct electrical transduction of target molecule binding. This is achieved because the surface-to-volume ratio of each semiconducting nanotrace 118 is large due to the small width 119 and depth 120 of the nanotrace 118 ( FIG. 1 Inset). Using nanoimprint lithography, nanotraces can be patterned with physical geometries that are comparable to the grain dimensions of the nanotraces 118 , making the molecular-semiconductor electronic interaction more pronounced. Nanodimension registration with the interdigitated finger regions of the source 116 and drain 117 is achieved using a nanoimprint processing tool such as Molecular Imprints Imprio 5500 (Austin, Tex.). Also noteworthy is that the distance between the gate electrode and the set of parallel nanotraces 115 is dictated by the thickness of layer 106 and is a known, regular distance for all of the nanotraces 118 in the set of parallel nanotraces 115 . This is in contrast to nanowire sensors where the distance between the active semiconductor nanowire and the electric field from gate electrode 105 can lead to background inhomogeneities in the response. The details of the method of nanoimprint lithography are defined further in the following sections of this description. Developing the Electrical Architecture for Addressing Each Drain Electrode [0032] After fabrication of the set of parallel semiconducting nanotraces 115 over each sensor device 102 , the remainder of the drain electrodes 104 B is deposited, FIG. 2D-F . Before addition of the drain electrode layer, a photoresist layer is spun over the entire surface and patterned, FIG. 2D . The pattern includes “islands” of photoresist 202 that are designed to protect the set of parallel nanotraces 115 . Source 109 and gate 108 electrode bonding pads are also protected during the remaining fabrication steps of multiplex detection array 101 (not shown in FIG. 2 ). Referring to FIG. 2D , an insulating oxide layer 111 (˜50-100 nm) is first deposited over the entire wafer to insure that contiguous drain electrodes 104 B are electrically isolated from the underlying layer and do not electrically short to source electrodes 103 . Electrical continuity between drain electrode stub bonding pad 110 and the drain electrode layer 104 E is created by first patterning a series of “vias” 112 through the oxide insulating layer 111 directly over each drain electrode stub bonding pad 110 . Vias 112 are created using a dry etch process with a patterned photoresist layer as the etch stop. After complete etching of the oxide in the vias 112 is insured, a tie layer (˜5 nm) and gold layer (˜100-200 nm) are deposited over oxide insulating layer 111 to a thickness that insures complete filling of vias 112 and electrical continuity to the drain electrode continuity pad pickup 113 in the drain electrode layer 104 B. Wet etching of the gold/tie layers lead to the formation of drain electrodes 104 B that terminate at drain electrode bonding pads 114 in an area remote from the sensor devices 102 . FIG. 2E shows the final drain electrode pattern. Drain electrodes 104 B are perpendicular to source 103 and gate 105 electrodes in the underlying layer. Drain electrodes 104 B provide electrical continuity between all sensor devices 102 in each row. FIG. 2E shows an example where a drain electrode 104 B is electrically contiguous between sensor devices forming the row 102 A, 102 B, 102 C and a second drain electrode 104 B is contiguous across the row containing sensor devices 102 D, 102 E, 102 F. Each of the drain electrodes terminates at a separate drain electrode bonding pad 114 which can be connected to an external electrical monitoring device. Preparing the Final Device for Microfluidic Coupling [0033] As a final measure, oxide protection layer 203 (˜100 nm) is deposited over the entire surface of multiplex detection array 101 as illustrated in FIG. 2F . In order to recover the set of semiconductor nanotraces 115 over each sensor device 102 for further biomolecular or chemical coupling, final photoepoxy resist layer 204 is spin-coated and patterned over sensor devices 102 to provide a bonding face for a microfluidic cover plate. Photoepoxy resist layer 204 serves two purposes. First, photoepoxy resist layer 204 acts as the etch stop during the oxide dry etch which removes the oxide material back to protection islands 202 over the set of parallel nanotraces 115 . After patterning of the photoepoxy resist, a dry etch process is used to remove the silicon dioxide from the final oxide protection layer 203 and the oxide layer 111 in that order. This produces access windows 205 to the semiconducting nanotraces 115 over each sensor device 102 . [0034] Photoepoxy resist layer 204 also serves as the final bonding and interface layer that makes contact to the microfluidic cover plate (described later). After the dry etch of the oxide layers is complete over protection islands 202 , and protection islands 202 are stripped from the surface of the set of parallel semiconductor nanotraces 115 , a light piranha etch (1 part 30% H 2 O 2 : 3 parts concentrated H 2 SO 4 ) removes any residual organic residue from the surface of the set of semiconductor nanotraces 115 yielding a pristine semiconductor surface for covalent attachment of probe molecules. As a final measure, multiplex detection device 101 is treated with an oxygen ashing step 10-30 minutes at a pressure of 700 mTorr at a power of 300 W with O 2 flow of 8 sccm. Oxygen ashing leads to diffusion of O − into the bulk lattice of the semiconducting nanotrace 118 surface and completes the stoichiometric ratios necessary to convert the nanotraces 118 into a suitable material for molecule coupling and direct electrical transduction. Oxygen ashing is carried out using an instrument such as a March Asher and is preceded by a thermal annealing step (10 min. at 200° C.) in ambient. DETAILED DESCRIPTION OF THE METHOD OF NANOIMPRINT LITHOGRAPHY [0035] Fabrication of the set of parallel semiconductor nanotraces 115 is one of the core features of multiplex detection array 101 . To fabricate the set of parallel nanotraces 115 , the method of Nanoimprint Lithography (NIL) is employed. NIL was first described in the prior art by U.S. Pat. No. 6,334,960, which is hereby incorporated by reference herein. FIGS. 3A-E illustrate the process for preparing the nanoimprint features into the active semiconducting layer. The first step is to fabricate imprint template 301 that is a separate component to multiplex detection array 101 . Template 301 is composed of a quartz wafer that has been previously patterned using electron beam lithography. The method for making the imprint template is described in the prior art by U.S. Pat. No. 6,334,960. Briefly, the electron beam writes individual features into an e-beam photoresist which after development appears as grooves in the resist. The pattern is transferred into a thin chromium layer ˜30 nm thick using a dry etch process. The chromium layer is then used as a hard etch stop during a dry etch of the quartz wafer. The e-beam written features appear as “grooves” 302 in quartz template 301 with the desired pattern. The chromium layer is stripped leaving a transparent, nanopatterned quartz template 301 as a free-standing wafer. Quartz template 301 is shown above multiplex detection array 101 wafer in FIG. 3A . For reference, the fabrication step of multiplex detection array 101 captured in FIG. 3A is that previously illustrated in FIG. 2B . As a final measure, self-assembled “release” monolayer 303 is applied to the surface of template 301 by immersing template 301 into solution overnight followed by rinsing of excess. The fabrication of quartz template 301 is considered the “slow” step. Once fabricated, it can be used to make many copies of the nanoimprint pattern. FIGS. 3B-E show a cross-sectional view of the processing steps for preparing the set of parallel semiconductor nanotraces 115 using template 301 . Template 301 is a full wafer which contains multiple copies of multiplex detection device 101 , referred herein as the “die”. The design of multiplex detection device 101 is created such that all of the sets of parallel nanotraces 115 for every sensor device 102 in a multiplex detection array 101 , and all copies, or dies of the multiplex detection array 101 are fabricated during a single NIL process. However, FIGS. 3A-E illustrates a cross-sectional view of the NIL process sequence that occurs over only a single sensor device 102 in one of the multiplex detection device 101 dies. [0036] Initially, quartz template 301 is positioned such that grooves 302 are registered over the interdigitated finger region of the sensor devices 102 . As illustrated previously in FIG. 2 C, the parallel set of semiconductor nanotraces 115 is perpendicular to interdigitated finger region of the source 116 and drain 117 portions of the electrodes spanning the distance therebetween. A hard mask or back anti-reflection coating (BARC) layer 304 (˜60 nm) is deposited onto the device layer stack which, in this cross-section, consists of semiconductor active layer 305 (˜20-100 nm) on gate dielectric 106 (˜20-100 nm) which is on gate electrode 105 (˜40 nm) and supported by substrate wafer 107 (˜500 um). The cross-section view in FIGS. 3A-E represents a view that is parallel to interdigitated finger regions of the source 116 and drain 117 electrodes, but is in the space between adjacent source 116 and drain 117 fingers so they do not appear in this cross-sectional view. [0037] After BARC layer 304 is spun cast onto the device stack, photoresist dispenser 306 places droplets of SFIL or other suitable nanoimprint photoresist 307 onto BARC layer 304 which spreads into a continuous thin layer 308 onto the surface. Referring to FIG. 3C , template 301 is brought into contact with photoresist 308 . Template 301 is angled onto layer 304 , so as to create a wave front of photoresist 308 . This wave front expels gas pockets, resulting in complete filling of grooves 302 of template 301 . Referring to FIG. 3D , ultraviolet light rays 309 (˜300 W/cm 2 , 20 s) expose photoresist 308 through template 301 . Photoresist 308 reacts and polymerizes into rigid imprint layer 310 . After exposure, template 301 is moved from the surface, leaving hard imprint layer 310 which have sharp imprint features 311 that are the negative of grooves 302 in template 301 . The remaining area is a thin residual layer 312 between raised imprinted features 311 . Template 301 is released from hard imprint layer 310 under the assistance of release layer 303 on template 301 , FIG. 3E . [0038] After hard imprint features 311 are formed, the features are “transferred” into semiconductor active layer 305 using a series of dry etch processes, FIGS. 4A-D . As a first step ( FIG. 4A ), a plasma dry etch system such as an Oxford Plasma Lab 80 RIE operating under a CHF 3 :O 2 environment (15 sccm CHF 3 , 7.5 sccm O 2 , p=25 mTorr) and a DC bias of ˜200 V was used to remove the residual silicon-containing SFIL polymer layer 312 at an etch rate of ˜30-40 nm/min. (˜50 s). A slight over-etch is used at this stage. This etch decreases the height of hard imprint features 311 while simultaneously removing residual layer 312 . The net effect of this etch is to reveal the surface of the BARC (organic) layer 304 . The next process is transfer of the pattern into the BARC layer using an organic dry etch of 100% O 2 (8 sccm, p=5 mTorr) and a DC bias of ˜200 V at an etch rate of 20-30 nm/min. (˜2 min. 15 s). The differential etch rate of the silicon-containing hard imprint layer 311 provides a means to selectively etch the BARC (organic) layer to the surface of semiconductor active layer 305 . The BARC layer 304 is used to smooth out small surface roughness in the wafer and make the final etch into the semiconductor active layer 305 more uniform. The geometry of the etched BARC features 401 under the hard imprint layer 311 is shown in FIG. 4C . [0039] Referring to FIG. 4D , a final plasma etch step consisting of an Ar:Cl 2 gas mixture (24 sccm Ar, 6 sccm Cl 2 , p=80 mTorr) at a bias of ˜200 V, and an etch rate of 10-15 nm/min. (˜1-3 mins. depending on the thickness of semiconductor active layer 305 ) is used to remove semiconductor active layer 305 and yield the set of parallel nanotraces 115 . Each semiconductor nanotrace 118 has the width 119 , depth 120 , and spacing 121 defined previously in FIG. 2C . Alternatively, a hard mask layer, for example chromium, can be used if necessary to achieve the selectively and aspect ratio desired for semiconductor nanotraces 118 . As a final step, FIG. 4E , etched hard imprint features 311 and etched BARC features 401 are removed using a piranha wet etch process. This process cleans the surface of semiconductor nanotraces 118 and prepares them for covalent attachment of probe molecules in later steps. [0040] FIG. 5 illustrates a High-Resolution Scanning Electron Microscope (HRSEM) cross-section micrograph of the process step just after nanoimprinting of the hard imprint features 311 over an example sensor device 102 ( FIG. 1 ) in multiplex detection array 101 . The photo micrographs are illustrative of the fabrication state depicted in FIG. 4A where base substrate 107 , a p-doped silicon wafer (˜500 μm) for example, is serving as gate electrode 105 . A silicon dioxide layer (˜100 nm) serves as gate dielectric 106 upon which the active semiconductor, SnO 2 layer 305 in this embodiment, is deposited (˜70 nm). A back anti-reflection layer 304 , Transpin™, is deposited on semiconductor active layer 305 , upon which final SFIL layer 308 is deposited and patterned with the alternating regions of raised hard imprint features 311 (˜150-300 in) and the thin residual layer 312 (˜20-80 nm). Width 501 and spacing 502 of hard imprint features 311 are equal to the final desired width 119 and depth 120 of the individual semiconductor nanotraces 118 . [0041] FIG. 6A illustrates a HRSEM photomicrograph after the breakthrough etch of the BARC layer 304 to semiconductor active layer 305 (example of etch state represented by FIG. 4C ). Access of the reactant gases to the surface of semiconductor 305 is illustrated as 601 in the figure. Additionally, residual organic debris 602 can be seen and the best results occur when the dry etch of BARC layer 304 is carried out to completion to remove these features. FIG. 6B illustrates the process after completion of the dry etch of semiconductor active layer 305 and stripping of the etched BARC layer 304 and etched hard imprint layer 311 (example of state in FIG. 4E ). The embodiment of semiconductor nanotraces 118 illustrated in FIG. 6B includes a semiconductor nanotraces design with bridging segments 603 between each semiconductor nanotrace 118 in the set of parallel semiconductor nanotraces 115 . While the semiconductor nanotrace “mesh” embodiment is slightly altered from the previous illustration, ultimately the individual nanotraces 118 possess the same width 119 and spacing 120 of original hard imprint features 312 . The pattern is simply altered by selection of a different design written into the template 301 . After the process depicted in FIG. 6B is completed and the set of parallel nanotraces 115 are formed and cleaned free of organics, the multiplex detection array 101 is ready for deposition of the anchor probe library. Synthesis of Anchor Probe Libraries on the Surface of the Active Semiconductor Nanotraces [0042] After fabrication of the electrical architecture of the multiplex detection device 101 illustrated previously in FIG. 2 , the set of parallel semiconductor nanotraces 115 for each sensor device 102 is functionalized with a sensitizing compound. FIGS. 7A-C illustrate the steps for coupling the sensitizing compounds onto the surface of the parallel set of semiconductor nanotraces 115 . Generally, each of the semiconductor nanotraces 118 within each parallel set of semiconductor nanotraces 115 receives the same sensitizing compound. In contrast, each parallel set of semiconductor nanotraces 115 on different sensor devices 102 receives a different sensitizing compound making it uniquely responsive to external targets relative to neighboring sensor devices 102 in the multiplex detection array 101 . The collection of all the sensitizing compounds for a given multiplex detection device 101 is called the library. Different sensitization compounds from the library are added to each sensor device 102 by partitioning the sensor devices 102 into different reaction wells during coupling. Methods to segregate the different sensor devices 102 on multiplex detection device 101 during coupling of the sensitization compounds is described later. [0043] Generally, the sensitizing compounds consist of “probe” molecules that are covalently attached to the surface of the semiconductor nanotraces 118 . The probes have specific affinity for different targets. Methods that provide a means for parallel deposition of each anchored probe in the library onto the respective sets of parallel semiconductor nanotraces 115 and all of the sensor devices 102 in the multiplex detection array 101 during a single process is preferred. Generally, the specific anchored probes that are selected to be in the library of a given multiplex test are chosen based on known outcomes from individual sensor device and are representative of the type of test that is being performed. This simplest case consists of a single sensor device 102 that responds to a single or a plurality of specific targets. [0044] In the preferred embodiment described in FIG. 7 , the probe molecules in the compound library are nucleic acid sequences that are designed to respond very specifically to the binding of the complementary sequence. In other embodiments, the anchored probes could be proteins that respond differentially when the binding of different antibodies occur. Similarly, polymers or other macromolecules that exclude or specifically bind different solution analytes or gas phase analytes can be used as the sensitizing compound which makes the sensor device 102 unique. In the embodiment where the probe library consists of short nucleic acid sequences (oligonucleotides), individual oligonucleotides can be synthesized directly from the surface of the semiconductor nanotraces 118 . A plurality of oligonucleotides can be synthesized onto the parallel set of semiconductor nanotraces on each sensor device using suitable methods such as PhotoGenerated Reagent (PGR) described in the prior art in U.S. Pat. No. 6,965,040, which is hereby incorporated by reference in its entirety. The method to deposit an anchor probe library of oligonucleotides using the method of PGR is illustrated in FIG. 7A-C and described below. [0045] Initially, multiplex detection device 101 , illustrated previously in FIG. 2F , is enclosed with microfluidic coverplate 701 , FIG. 7A . Microfluidic plate 701 consists of a series of fluidic wells 702 (˜15 um in depth) that are connected by a network of fluidic channels 703 (−90 um in depth) that work back to a single entrance and exit port (not shown) where fluidic coupling is made externally to a fluid manifold. The fluidic network consists of both parallel and serial connections of individual fluid wells 702 via fluidic network of channels 703 . Microfluidic cover plate 701 can be glass or other suitable molded plastic component that provides a leak-tight seal between fluid wells 702 . Additionally, the fluidic cover plate wafer must be transparent to support photoactivation of certain reagents during optical irradiation using the method of PGR. Each microfluidic well 702 is designed to fully enclose a single sensor device 102 in multiplex detection array 101 . Each microfluidic well 702 provides a reaction center where photogenerated acid can diffuse throughout, but cannot cross into neighboring microfluidic wells 702 . While synthesis of nucleic acid anchor probes is illustrated as the preferred embodiment in FIGS. 7A-C , other probe-specific classes such as proteins, small metabolites, nanoparticles, polymer nanospheres and other receptors for gas phases targets can also be deposited, or synthesized, depending on the application. Additionally, some of the sensor devices 102 in multiplex detection array 101 can be employed as references and controls. These sensor devices 102 would receive special sensitization compounds that may exclude, trap, or permit only a specific entity in the environment surrounding the semiconductor nanotraces 118 . Likewise, sensor devices 102 may be designed to bind known sequences spiked into the sample solution, for example, as a positive control. [0046] FIG. 7B illustrates the state of the multiplex detection array 101 after completion of the method of PGR. At this point, the microfluidic cover plate 702 is removed and the net result is a multiplex detection array 101 where the set of parallel nanotraces 115 on each sensor device 102 has a unique anchor probe molecule 704 synthesized on the surface of all of the semiconductor nanotraces 118 in the set of parallel nanotraces 115 . FIG. 7B inset (i) illustrates that a plurality of copies of the same anchor probe oligonucleotide molecule 704 are synthesized from the surface of semiconductor nanotrace 118 and are limited only by the molecular packing density of the anchor probe molecules 704 . At the end of the PGR process, the semiconductor nanotraces 118 for each sensor device 102 possess anchor probe molecules 704 covalently coupled to the surface where, in this example, the anchor probe sequence 705 is unique to a single sensor device 102 . The unique anchor probe sequence 705 , FIG. 7 B(ii) for each sensor device 102 is dictated exclusively by the fluidic confinement of the PGR reagents within each microfluidic well 702 that enshroud the set of semiconductor nanotraces 115 on each sensor device 102 . The number of different or redundant anchor probes 704 in the multiplex detection array 101 library is limited only by the number of sensor devices 102 and corresponding microfluidic wells 702 designed in the microfluidic cover plate 701 . [0047] As a final measure, multiplex detection array 101 with anchored probes 704 is packaged onto electronics board 706 , FIG. 7C . Electrode bonding pads on multiplex detection device 101 are made contiguous with the electronics board 706 using a suitable technique such as wire or bump bonding. In the embodiment shown in FIG. 7C , a wire bond 707 connection is made between gate electrode bonding pad 108 and gate electronics control lead 708 . Additionally, wire bond 709 between the source electrode bonding pad 109 and source electronics control lead 710 , and wire bond 711 between the drain electrode bonding pad 114 and drain electronics control lead 712 are made. Some level of embedded logic is also included on the electronics board 706 (not shown) that enables multiplex signal acquisition, processing and results determination. Detection of the Target Molecules [0048] In the case of the preferred embodiment described above, the multiplex detection array 101 would be packaged within a common fluidic-tight vessel (not shown) that serves as the sample fluid reaction chamber which brings together the sample fluid with the multiplex detection array 101 . For example, in the case of a diagnostic test for a virulent pathogen, the target nucleic acid sequence would bind with its complementary anchored probe oligonucleotide sequence 705 on one of the sensor devices 102 in the multiplex detection array 101 . The sensor device 102 that bears the matching anchored probe oligonucleotide sequence 705 that is complementary to the target would incur a change in the source-drain electrical current which would be measured in the external circuit. A temperature controller device can be used to insure that the conditions for optimum binding affinity are achieved during reaction. A solid state cooler/heater device such as a thermoelectric cooler, for example, may be used in the instrument and pushed up against the cartridge when it is inserted into the instrument. Signal processing from the embedded control logic would then indicate to the user that the presence of the target nucleic acid sequence corresponding to a match with the known anchor probe sequence 705 was present in the sample. The result would be displayed on a digital display device that is part of the analysis instrument. The user would then determine a course of action based on the result of the diagnostic test. In the simplest case, a single sensor device 102 is used to determine the identity of an unknown target. The multiplex detection array 101 is designed to assess the presence of a single or plurality of targets during a single sample introduction onto multiplex detection array 101 . The embedded control logic makes a continuous measurement of the current in all of the sensor, reference and control devices 102 in the multiplex detection array 101 . [0049] In alternate embodiments, the anchored probe oligonucleotide would be designed to look for a specific sequence that had been expressed such as RNA, or DNA that is specific to a particular organism. In other embodiments, the anchor probes may be nucleic acid sequences that have been selected based on a specific affinity to a target molecule or entity on a surface, e.g. a cell wherein the anchored probe sequence coils into a 3D conformation that interacts with the target in the form of an aptamer. In another embodiment, the anchor probe molecule may be a protein that has a specific affinity for a target protein or antigen, or the anchor probe molecule may be a small molecule that has a specific affinity for another molecule or ion in solution. [0050] FIG. 8A-B illustrates the chemical binding effect of targets to the anchor probe molecules 704 on multiplex detection array 101 . In this embodiment, anchor probes 704 synthesized on the surface of semiconductor nanotraces 118 display a baseline current 801 that is measured and recorded prior to introduction of target molecules 802 , FIG. 8B . Upon addition of target molecule 802 to the fluid space above sensor device 102 ( FIG. 8B ), and if the target sequence 802 matches the anchor probe sequence 705 on any given sensor device 102 in the multiplex detection array 101 , it will hybridize with the surface complement. Upon hybridization, the current traveling through the semiconductor nanotrace 118 will change at the point indicated by 803 . Because anchor probe sequence 705 of sensor device 102 that undergoes a change in current is known, the identity of the unknown target sequence 802 can be made. The change in the current will be a new value 804 that indicates the presence of target 802 . The magnitude and direction of the change in current is indicative of the concentration of target, nature of the surface interaction, local electric field and properties of the semiconductor nanotraces. The properties of the semiconductor nanotraces can be influenced by the doping level, external field applied by the gate electrode and other things that can affect or change the majority carrier concentration and mobility. [0051] Although the present invention has been described with reference to specific details, it is not intended that such details should be regarded as limitations of the scope of the invention, except as and to the extent that they are included in the accompanying claims.

An array of sensor devices, each sensor including a set of semiconducting nanotraces having a width less than about 100 nm is provided. Method for fabricating the arrays is disclosed, providing a top-down approach for large arrays with multiple copies of the detection device in a single processing step. Nanodimensional sensing elements with precise dimensions and spacing to avoid the influence of electrodes are provided. The arrays may be used for multiplex detection of chemical and biomolecular species. The regular arrays may be combined with parallel synthesis of anchor probe libraries to provide a multiplex diagnostic device. Applications for gas phase sensing, chemical sensing and solution phase biomolecular sensing are disclosed.

big_patent

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Application Ser. No. 61/378,776, filed Aug. 31, 2010, entitled “SINGULATION METHOD FOR SEMICONDUCTOR PACKAGE WITH PLATING ON SIDE OF CONNECTORS” and to U.S. Provisional Application Ser. No. 61/412,183, filed Nov. 10, 2010, entitled “SINGULATION AND PLATING METHOD FOR SEMICONDUCTOR PACKAGE,” both of which are hereby incorporated by reference in their entirety as if set forth herein. FIELD OF THE INVENTION The present invention relates to the field of semiconductor packages. More specifically, the present invention relates to a singulation and plating method for semiconductor packages. BACKGROUND OF THE INVENTION FIG. 1 is a perspective view of a prior art semiconductor package 100 having a top surface 110 a and side surfaces 110 b formed by a molding compound. A leadframe is encased in the molding compound, with the top surfaces 120 a and side surfaces 120 b of its leads being exposed. The region 130 of the leadframe corresponding to the die attach pad of the leadframe is also exposed. As seen in FIG. 1 , although the top surfaces 120 a and region 130 might be plated with a plating material, the sides 120 b of the leads, or connectors, in a conventional package 100 are not plated. As a result of the side surfaces 120 b of the leads not being plated, their exposed surface, typically copper, is easy to react with oxygen, thereby resulting in undesirable oxide on the surface of the leads. The contaminated surface will create problems when the semiconductor package 100 is soldered into a printed circuit board. SUMMARY OF THE INVENTION The present invention provides a new, useful, and non-obvious method of singulating and plating semiconductor packages, employing plating of the side surfaces of the leads of the leadframe in order to prevent contamination of the lead surfaces. In one aspect of the present invention, a method of singulating semiconductor packages comprises: providing a plurality of semiconductor dies coupled to a single common leadframe, wherein a molding compound at least partially encases the semiconductor dies and the leadframe; singulating the plurality of semiconductor dies, wherein the leadframe is at least partially cut between adjacent semiconductor dies, thereby forming exposed side surfaces on leads of the leadframe; and plating the exposed side surfaces of the leads with a plating material, wherein the plating material is a different material than the leads. In some embodiments, the leads are copper. In some embodiments, the plating material is a metallic material. In some embodiments, the plating material is tin, silver, gold, nickel-gold, nickel-palladium, or nickel-palladium-gold. In some embodiments, the leadframe has a top surface and a bottom surface opposite the top surface, and the step of singulating the plurality of semiconductor dies comprises performing a full cut of the leadframe in a single cutting operation before the step of plating the exposed side surfaces, wherein the full cut extends all the way between the top surface and the bottom surface. In some embodiments, the semiconductor dies are attached to the bottom surface of the leadframe, and the method further comprises plating the top surface of the leadframe before the step of singulating the plurality of semiconductor dies. In some embodiments, the semiconductor dies are attached to the bottom surface of the leadframe, and the method further comprises plating the top surface of the leadframe after the step of singulating the plurality of semiconductor dies. In some embodiments, the leadframe has a top surface and a bottom surface opposite the top surface, and the step of singulating the plurality of semiconductor dies comprises: performing a first partial cut of the leadframe, wherein the first partial cut does not extend all the way between the bottom surface and the top surface; and performing a second partial cut of the leadframe, wherein the second partial cut is performed separately from the first partial cut and completes the singulation of the semiconductor dies all the way between the bottom surface and the top surface of the leadframe, thereby forming a plurality of singulated semiconductor packages. In some embodiments, the step of plating the exposed side surfaces is performed in between the first partial cut and the second partial cut. In some embodiments, the semiconductor dies are attached to the bottom surface of the leadframe, and the method further comprises plating the top surface of the leadframe, wherein the plating of the top surface is performed before the first partial cut. In some embodiments, the semiconductor dies are attached to the bottom surface of the leadframe, and the method further comprises plating the top surface of the leadframe, wherein the plating of the top surface is performed between the first partial cut and the second partial cut. In some embodiments, the first partial cut is performed using a blade having a first thickness and the second partial cut is performed using a blade having a second thickness, wherein the first thickness and the second thickness are different. In some embodiments, the second thickness is larger than the first thickness. In some embodiments, the second partial cut forms a step on sides of the singulated semiconductor packages. In some embodiments, the first partial cut or the second partial cut is performed using a blade having a beveled edge. In some embodiments, the step of providing the plurality of semiconductor dies comprises: coupling the semiconductor dies to the single common leadframe; wire bonding the semiconductor dies to leads of the leadframe; and at least partially encasing the semiconductor dies and the leadframe in a molding compound. In another aspect of the present invention, a singulated semiconductor package comprises: a leadframe having a die attach pad and a plurality of leads; a semiconductor die coupled to the die attach pad of the leadframe; and a molding compound at least partially encasing the leadframe and the semiconductor die, wherein side surfaces of the leads are exposed through the molding compound, and wherein the side surfaces of the leads are plated with a plating material, the plating material being a different material than the leads. In some embodiments, the leads are copper. In some embodiments, the plating material is a metallic material. In some embodiments, the plating material is tin, silver, gold, nickel-gold, nickel-palladium, or nickel-palladium-gold. In some embodiments, the mold compound comprises a top surface, a bottom surface, and side surfaces between the top surface and the bottom surface, wherein the side surfaces comprise a step. In some embodiments, the mold compound comprises a top surface, a bottom surface, and side surfaces between the top surface and the bottom surface, wherein the side surfaces comprise a beveled portion. In some embodiments, the mold compound comprises a top surface, a bottom surface, and side surfaces between the top surface and the bottom surface, wherein the side surfaces comprise a beveled portion and a non-beveled portion. In some embodiments, the semiconductor die is wire bonded to the leads of the leadframe. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a prior art semiconductor package. FIG. 2 is a perspective view of a semiconductor package in accordance with some embodiments of the present invention. FIGS. 3A-H illustrate different stages of a singulation and plating process using full cutting in accordance with some embodiments of the present invention. FIGS. 4A-G illustrate different stages of another singulation and plating process using full cutting in accordance with some embodiments of the present invention. FIG. 5A is a perspective view of the top of a semiconductor package formed with full cutting in accordance with some embodiments of the present invention. FIG. 5B is a perspective view of the bottom of the semiconductor package with full cutting in accordance with some embodiments of the present invention. FIGS. 6A-H illustrate different stages of a singulation and plating process using partial cutting in accordance with some embodiments of the present invention. FIGS. 7A-G illustrate different stages of another singulation and plating process using partial cutting in accordance with some embodiments of the present invention. FIG. 8 is a cross-sectional perspective view of a partial cutting of a semiconductor package in accordance with some embodiments of the present invention. FIG. 9A is a perspective view of the bottom of a semiconductor package having a first step height formed with partial cutting in accordance with some embodiments of the present invention. FIG. 9B is a perspective view of the top of the semiconductor package having a first step height formed with partial cutting in accordance with some embodiments of the present invention. FIG. 10A is a perspective view of the bottom of a semiconductor package having a second step height formed with partial cutting in accordance with some embodiments of the present invention. FIG. 10B is a perspective view of the top of the semiconductor package having a second step height formed with partial cutting in accordance with some embodiments of the present invention. FIGS. 11A-H illustrate different stages of a singulation and plating process using partial cutting with a partial bevel-edged blade in accordance with some embodiments of the present invention. FIGS. 12A-G illustrate different stages of another singulation and plating process using partial cutting with a partial bevel-edged blade in accordance with some embodiments of the present invention. FIG. 13 is a cross-sectional perspective view of a partial cutting of a semiconductor package with both partial and full bevel-edged blades in accordance with some embodiments of the present invention. FIG. 14A is a perspective view of the bottom of a semiconductor package having a beveled side surface formed with a partial bevel-edged blade in accordance with some embodiments of the present invention. FIG. 14B is a perspective view of the top of the semiconductor package having a beveled side surface formed with a partial bevel-edged blade in accordance with some embodiments of the present invention. FIG. 15A is a perspective view of the bottom of a semiconductor package having a beveled side surface with a first height formed with a full bevel-edged blade in accordance with some embodiments of the present invention. FIG. 15B is a perspective view of the top of the semiconductor package having a beveled side surface with a first height formed with a full bevel-edged blade in accordance with some embodiments of the present invention. FIG. 16A is a perspective view of the bottom of a semiconductor package having a beveled side surface with a second height formed with a full bevel-edged blade in accordance with some embodiments of the present invention. FIG. 16B is a perspective view of the top of the semiconductor package having a beveled side surface with a second height formed with a full bevel-edged blade in accordance with some embodiments of the present invention. DETAILED DESCRIPTION OF THE INVENTION The following description is presented to enable one of ordinary skill in the art to make and use the invention and is provided in the context of a patent application and its requirements. Various modifications to the described embodiments will be readily apparent to those skilled in the art and the generic principles herein may be applied to other embodiments. Thus, the present invention is not intended to be limited to the embodiment shown but is to be accorded the widest scope consistent with the principles and features described herein. This disclosure provides several embodiments of the present invention. It is contemplated that any features from any embodiment can be combined with any features from any other embodiment. In this fashion, hybrid configurations of the disclosed embodiments are well within the scope of the present invention. The present invention provides a new, useful, and non-obvious method of singulating and plating semiconductor packages, employing plating of the side surfaces of the leads of the leadframe in order to prevent contamination of the lead surfaces. FIG. 2 is a perspective view of a semiconductor package 200 in accordance with some embodiments of the present invention. The semiconductor package 200 has a top surface 210 a and side surfaces 210 b preferably formed by a molding compound. A leadframe is encased in the molding compound, with the top surfaces 220 a and side surfaces 220 b of its leads being exposed. In some embodiments, the leads are copper. However, it is contemplated that other materials besides copper can be used to form the leads. In some embodiments, the region 230 of the leadframe corresponding to the die attach pad of the leadframe is also exposed. As seen in FIG. 2 , not only are the top surfaces 220 a and region 230 plated with a plating material, but the sides 220 b of the leads, or connectors, are plated with a plating material as well. In some embodiments, the plating material on the surfaces 220 a , 220 b , and 230 is a material configured not to react with oxygen. As a result, the plated surfaces have a good soldering result when the semiconductor package 200 is attached to a printed circuit board. In some embodiments, the plating material is a metallic material. In some embodiments, the plating material is tin. Other materials that can be used as the plating material include, but are not limited to, silver, gold, nickel-gold, nickel-palladium, and nickel-palladium-gold. In a preferred embodiment, the sides of the leadframe connectors are plated after they are singulated in strip form. In some embodiments, the singulation processes of the present invention, such as those discussed below, involve taking a wafer containing multiple, preferably identical, semiconductor dies coupled to a leadframe, and reducing it into individual semiconductor packages each containing one of those dies. It is contemplated that the present invention can employ a variety of different plating processes and techniques in order to plate the surfaces of the leads. In some embodiments, the present invention can employ any of the plating processes and techniques disclosed in U.S. patent application Ser. No. 12/579,574, filed Oct. 15, 2009, and entitled “METALLIC SOLDERABILITY PRESERVATION COATING ON METAL PART OF SEMICONDUCTOR PACKAGE TO PREVENT OXIDE,” which is hereby incorporated by reference in its entirety as if set forth herein It is noted that reference is made in this disclosure to “top” and “bottom” surfaces. The purpose of using the terms “top” and “bottom” with respect to the surfaces is to help identify these surfaces as being opposite one another and to help identify the “side” surfaces as being the surfaces between the “top” and “bottom” surfaces. Therefore, in certain portions of this disclosure, “top” surfaces can appear to be on the bottom and “bottom” surfaces can appear to be on the top if the positioning of the semiconductor package has been changed. FIGS. 3A-H illustrate different stages of a singulation and plating process using full cutting in accordance with some embodiments of the present invention. In FIG. 3A , a plurality of semiconductor dies 320 are each coupled to a surface of the same leadframe 310 (e.g., a leadframe strip). In a preferred embodiment, each of the semiconductor dies 320 is attached to a die attach pad on the leadframe 310 . The leadframe 310 comprises a side surface 305 that extends between a bottom surface 315 of the leadframe and the top surface of the leadframe (i.e., the surface to which the semiconductor dies are attached). It is contemplated that the semiconductor dies 320 can be coupled to the leadframe 310 in a variety of different ways, including, but not limited to, using soldering flux. In FIG. 3B , the semiconductor dies 320 are wire bonded to the leadframe 310 using wires 330 . It is contemplated that a variety of different types of materials can be used to form the bonding wires 330 , including, but not limited to, aluminum, copper, and gold. In FIG. 3C , a molding process is performed to encase the semiconductor dies 320 , the leadframe 310 , and the bonding wires 330 in a molding compound 340 . In FIG. 3D , a plating process is performed to plate the bottom surface 315 with a plating material 350 . In a preferred embodiment, the plating material 350 is a material configured not to react with oxygen. In some embodiments, the plating material 350 is a metallic material. In some embodiments, the plating material 350 is tin. Other materials that can be used as the plating material 350 include, but are not limited to, silver, gold, nickel-gold, nickel-palladium, and nickel-palladium-gold. In FIG. 3E , a singulation process is performed on the leadframe strip 310 . In a preferred embodiment, the leadframe strip 310 is placed on a support 365 , and blades 360 are used to completely singulate the semiconductor packages in one full cutting operation. In some embodiments, as seen in FIG. 3E , the bottom surface 315 is facing upward during the full cutting operation. However, it is contemplated that the bottom surface 315 can be alternatively positioned, such as facing downwards, sideways, or at an angle. In FIG. 3F , the side surfaces 305 of the leads between neighboring semiconductor dies are exposed as a result of the singulation process. The singulated semiconductor packages can now be loaded to another plating process. In FIG. 3G , the exposed side surfaces 305 of the leads are plated with a plating material 355 . As discussed above, the plating material 355 is preferably a material configured not to react with oxygen. In some embodiments, the plating material 355 is a metallic material. In some embodiments, the plating material 355 is tin. Other materials that can be used as the plating material 350 include, but are not limited to, silver, gold, and nickel-gold. FIG. 3H shows the finished individual semiconductor packages 300 , similar to the semiconductor package 200 in FIG. 2 . Each semiconductor package 300 has a semiconductor die 320 and a leadframe 310 at least partially encased in the molding compound 340 , with the leads of each leadframe 310 being accessible to electrical coupling via the plating material 350 and 355 over the portions of the leads that are exposed from the molding compound 340 . Each semiconductor package 300 has side surfaces 342 that are formed from the molding compound 340 . In some embodiments, the side surfaces 342 are straight from top to bottom, as shown in FIG. 3H . FIGS. 4A-G illustrate different stages of another singulation and plating process using full cutting in accordance with some embodiments of the present invention. In FIG. 4A , a plurality of semiconductor dies 420 are each coupled to a surface of the same leadframe 410 (e.g., a leadframe strip). In a preferred embodiment, each of the semiconductor dies 420 is attached to a die attach pad on the leadframe 410 . The leadframe 410 comprises a side surface 405 that extends between a bottom surface 415 of the leadframe and the top surface of the leadframe (i.e., the surface to which the semiconductor dies are attached). It is contemplated that the semiconductor dies 420 can be coupled to the leadframe 410 in a variety of different ways, including, but not limited to, using soldering flux. In FIG. 4B , the semiconductor dies 420 are wire bonded to the leadframe 410 using wires 430 . It is contemplated that a variety of different types of materials can be used to form the bonding wires 430 , including, but not limited to, aluminum, copper, and gold. In FIG. 4C , a molding process is performed to encase the semiconductor dies 420 , the leadframe 410 , and the bonding wires 430 in a molding compound 440 . In FIG. 4D , a singulation process is performed on the leadframe strip 410 . In a preferred embodiment, the leadframe strip 410 is placed on a support 465 , and blades 460 are used to completely singulate the semiconductor packages in one full cutting operation. In some embodiments, as seen in FIG. 4D , the bottom surface 415 is facing upward during the full cutting operation. However, it is contemplated that the bottom surface 415 can be alternatively positioned, such as facing downwards, sideways, or at an angle. In FIG. 4E , the side surfaces 405 of the leads between neighboring semiconductor dies are exposed as a result of the singulation process. The singulated semiconductor packages can now be loaded to a plating process. In FIG. 4F , a plating process is performed to plate the bottom surfaces 415 and the side surfaces 405 with a plating material 450 and 455 , respectively. In a preferred embodiment, the plating material is a material configured not to react with oxygen. In some embodiments, the plating material is a metallic material. In some embodiments, the plating material is tin. Other materials that can be used as the plating material include, but are not limited to, silver, gold, nickel-gold, nickel-palladium, and nickel-palladium-gold. FIG. 4G shows the finished individual semiconductor packages 400 , similar to the semiconductor package 200 in FIG. 2 . Each semiconductor package 400 has a semiconductor die 420 and a leadframe 410 at least partially encased in the molding compound 440 , with the leads of each leadframe 410 being accessible to electrical coupling via the plating material 450 and 455 over the portions of the leads that are exposed from the molding compound 440 . Each semiconductor package 400 has side surfaces 442 that are formed from the molding compound. In some embodiments, the side surfaces 442 are straight from top to bottom, as shown in FIG. 4H . FIGS. 5A and 5B illustrate perspective views of the top and the bottom of a semiconductor package 500 formed with full cutting in accordance with some embodiments of the present invention. Semiconductor package 500 has a top surface 510 a , a bottom surface 510 c opposite the top surface 510 a , and side surfaces 510 b between top surface 510 a and bottom surface 510 c , preferably all formed by a molding compound. A leadframe is encased in the molding compound, with the top surfaces 520 a and side surfaces 520 b of its leads being exposed. In some embodiments, the leads are copper. However, it is contemplated that other materials besides copper can be used to form the leads. In some embodiments, the region 530 of the leadframe corresponding to the die attach pad of the leadframe is also exposed. The top surfaces 520 a , side surfaces 520 b , and region 530 are plated with a plating material. In some embodiments, the plating material on the surfaces is a material configured not to react with oxygen. In some embodiments, the plating material is a metallic material. In some embodiments, the plating material is tin. Other materials that can be used as the plating material include, but are not limited to, silver, gold, nickel-gold, nickel-palladium, and nickel-palladium-gold. In some embodiments, the side surfaces 510 b of the semiconductor package 500 are straight, as seen in FIGS. 5A-B . However, it is contemplated that the side surfaces of the semiconductor package can be configured in other shapes, as will be discussed in more detail below. FIGS. 6A-H illustrate different stages of a singulation and plating process using partial cutting in accordance with some embodiments of the present invention. In FIG. 6A , a plurality of semiconductor dies 620 are each coupled to a surface of the same leadframe 610 (e.g., a leadframe strip). In a preferred embodiment, each of the semiconductor dies 620 is attached to a die attach pad on the leadframe 610 . The leadframe 610 comprises a side surface 605 that extends between a bottom surface 615 of the leadframe and the top surface of the leadframe (i.e., the surface to which the semiconductor dies are attached). It is contemplated that the semiconductor dies 620 can be coupled to the leadframe 610 in a variety of different ways, including, but not limited to, using soldering flux. The semiconductor dies 620 are wire bonded to the leadframe 610 using wires 630 . It is contemplated that a variety of different types of materials can be used to form the bonding wires 630 , including, but not limited to, aluminum, copper, and gold. In FIG. 6B , a molding process is performed to encase the semiconductor dies 620 , the leadframe 610 , and the bonding wires 630 in a molding compound 640 . In FIG. 6C , a plating process is performed to plate the bottom surface 615 with a plating material 650 . In a preferred embodiment, the plating material 650 is a material configured not to react with oxygen. In some embodiments, the plating material 650 is a metallic material. In some embodiments, the plating material 650 is tin. Other materials that can be used as the plating material 650 include, but are not limited to, silver, gold, nickel-gold, nickel-palladium, and nickel-palladium-gold. In FIG. 6D , a partial singulation process is performed on the leadframe strip 610 . In a preferred embodiment, blades 660 are used to partially singulate the semiconductor packages. For example, in some embodiments, the blades 660 cut through the entire leadframe 610 , but do not pass through all of the molding compound 640 , thereby forming side surface 642 of the molding compound between neighboring semiconductor dies 620 , but still leaving the individual semiconductor packages attached to one another. In FIG. 6E , the side surfaces 605 of the leads between neighboring semiconductor dies 620 are exposed as a result of the partial singulation process. The singulated semiconductor packages can now be loaded to another plating process. In FIG. 6F , the exposed side surfaces 605 of the leads are plated with a plating material 655 . As discussed above, the plating material 655 is preferably a material configured not to react with oxygen. In some embodiments, the plating material 655 is a metallic material. In some embodiments, the plating material 655 is tin. Other materials that can be used as the plating material 650 include, but are not limited to, silver, gold, and nickel-gold. In FIG. 6G , another partial singulation process is performed on the leadframe strip 610 in order to complete the singulation of the semiconductor packages. In a preferred embodiment, blades 662 are used to singulate the semiconductor packages. In some embodiments, the blades 662 have a different shape than the blades 660 of the first partial singulation process in FIG. 6D . In some embodiments, the blades 662 have a different thickness than the blades 660 . In some embodiments, the blades 662 have a greater thickness than the blades 660 . FIG. 6H shows the finished individual semiconductor packages 600 , similar to the semiconductor package 200 in FIG. 2 . Each semiconductor package 600 has a semiconductor die 620 and a leadframe 610 at least partially encased in the molding compound 640 , with the leads of each leadframe 610 being accessible to electrical coupling via the plating material 650 and 655 over the portions of the leads that are exposed from the molding compound 640 . Each semiconductor package 600 has side surfaces that are formed from the molding compound 640 . FIG. 6H shows the side surfaces of semiconductor package 600 having a first portion 642 , formed from the first partial singulation blade 660 , and a second portion 644 , formed from the second partial singulation blade 662 . Since the second singulation blade 662 was thicker than the first singulation blade 660 , a step is formed on the side of the semiconductor package 600 . FIGS. 7A-G illustrate different stages of another singulation and plating process using partial cutting in accordance with some embodiments of the present invention. In FIG. 7A , a plurality of semiconductor dies 720 are each coupled to a surface of the same leadframe 710 (e.g., a leadframe strip). In a preferred embodiment, each of the semiconductor dies 720 is attached to a die attach pad on the leadframe 710 . The leadframe 710 comprises a side surface 705 that extends between a bottom surface 715 of the leadframe and the top surface of the leadframe (i.e., the surface to which the semiconductor dies are attached). It is contemplated that the semiconductor dies 720 can be coupled to the leadframe 710 in a variety of different ways, including, but not limited to, using soldering flux. The semiconductor dies 720 are wire bonded to the leadframe 710 using wires 730 . It is contemplated that a variety of different types of materials can be used to form the bonding wires 730 , including, but not limited to, aluminum, copper, and gold. In FIG. 7B , a molding process is performed to encase the semiconductor dies 720 , the leadframe 710 , and the bonding wires 730 in a molding compound 740 . In FIG. 7C , a partial singulation process is performed on the leadframe strip 710 . In a preferred embodiment, blades 760 are used to partially singulate the semiconductor packages. For example, in some embodiments, the blades 760 cut through the entire leadframe 710 , but do not pass through all of the molding compound 740 , thereby forming side surface 742 of the molding compound between neighboring semiconductor dies 720 , but still leaving the individual semiconductor packages attached to one another. In FIG. 7D , the side surfaces 705 of the leads between neighboring semiconductor dies 720 are exposed as a result of the partial singulation process. The singulated semiconductor packages can now be loaded to a plating process. In FIG. 7E , the bottom surfaces 715 and the exposed side surfaces 705 of the leads are plated with a plating material 750 and 755 , respectively. As discussed above, the plating material is preferably a material configured not to react with oxygen. In some embodiments, the plating material is a metallic material. In some embodiments, the plating material is tin. Other materials that can be used as the plating material include, but are not limited to, silver, gold, nickel-gold, nickel-palladium, and nickel-palladium-gold. In FIG. 7F , another partial singulation process is performed on the leadframe strip 710 in order to complete the singulation of the semiconductor packages. In a preferred embodiment, blades 762 are used to singulate the semiconductor packages. In some embodiments, the blades 762 have a different shape than the blades 760 of the first partial singulation process in FIG. 7C . In some embodiments, the blades 762 have a different thickness than the blades 760 . In some embodiments, the blades 762 have a greater thickness than the blades 760 . FIG. 7G shows the finished individual semiconductor packages 700 , similar to the semiconductor package 200 in FIG. 2 . Each semiconductor package 700 has a semiconductor die 720 and a leadframe 710 at least partially encased in the molding compound 740 , with the leads of each leadframe 710 being accessible to electrical coupling via the plating material 750 and 755 over the portions of the leads that are exposed from the molding compound 740 . Each semiconductor package 700 has side surfaces that are formed from the molding compound 740 . FIG. 7G shows the side surfaces of semiconductor package 700 having a first portion 742 , formed from the first partial singulation blade 760 , and a second portion 744 , formed from the second partial singulation blade 762 . Since the second singulation blade 762 was thicker than the first singulation blade 760 , a step is formed on the side of the semiconductor package 700 . FIG. 8 is a cross-sectional perspective view of a partial cutting of a semiconductor package 800 in accordance with some embodiments of the present invention. In FIG. 8 , semiconductor package 800 comprises a semiconductor die and a leadframe encased within a molding compound, with the side surface of leads 820 b being exposed from the molding compound. During the partial singulation cutting of the semiconductor package 800 , a cutting blade 860 cuts through the molding compound and/or the leadframe. In FIG. 8 , the cutting blade 860 is shown cutting through the bottom surface 810 c of the semiconductor package 800 , which is positioned with its bottom surface 810 c facing upwards. In some embodiments, different blades are used for different cuttings. For example, in FIG. 8 , blade assembly 860 comprises a blade 862 extending from a shank 864 , which is used by a tool to hold and manipulate the blade 862 . During a first cutting operation, a first blade can be stopped at a certain depth of the semiconductor package 800 . In a subsequent cutting operation, a second blade having a different thickness as the first blade can be used to cut through the remaining portion of the semiconductor package 800 . In some embodiments, this subsequent cutting operation is performed from an opposite side of the semiconductor package 800 as the first cutting operation. As a result of the different thicknesses of the blades, a step can be formed between a first side surface 810 b , formed by the thinner blade, and a second side surface 815 b , formed by the thicker blade. FIGS. 9A and 9B illustrate perspective views of the bottom and top of a semiconductor package 900 having a first step height formed with partial cutting in accordance with some embodiments of the present invention. In some embodiments, the semiconductor package 900 is singulated and its step is formed using a blade assembly such as blade 860 in FIG. 8 . Semiconductor package 900 has a top surface 910 a , a bottom surface 910 c opposite the top surface 910 a , and side surfaces between top surface 910 a and bottom surface 910 c , preferably all formed by a molding compound. A leadframe is encased in the molding compound, with the top surfaces 920 a and side surfaces 920 b of its leads being exposed. In some embodiments, the leads are copper. However, it is contemplated that other materials besides copper can be used to form the leads. In some embodiments, the region 930 of the leadframe corresponding to the die attach pad of the leadframe is also exposed. The top surfaces 920 a , side surfaces 920 b , and region 930 are plated with a plating material. In some embodiments, the plating material on the surfaces is a material configured not to react with oxygen. In some embodiments, the plating material is a metallic material. In some embodiments, the plating material is tin. Other materials that can be used as the plating material include, but are not limited to, silver, gold, nickel-gold, nickel-palladium, and nickel-palladium-gold. In some embodiments, the side surfaces of the semiconductor package 900 have a first portion 910 b , formed from a first partial singulation blade, and a second portion 915 b , formed from a second partial singulation blade that is thicker than the first partial singulation blade. As a result of the second singulation blade being thicker than the first singulation blade, a step is formed on the side of the semiconductor package 900 . FIGS. 10A and 10B illustrate perspective views of the bottom and top of a semiconductor package 1000 having a second step height formed with partial cutting in accordance with some embodiments of the present invention. Semiconductor package 1000 is almost identical to semiconductor package 900 , except for the height of the step on its side surface. Semiconductor package 1000 has a top surface 1010 a , a bottom surface 1010 c opposite the top surface 1010 a , and side surfaces between top surface 1010 a and bottom surface 1010 c , preferably all formed by a molding compound. A leadframe is encased in the molding compound, with the top surfaces 1020 a and side surfaces 1020 b of its leads being exposed. In some embodiments, the leads are copper. However, it is contemplated that other materials besides copper can be used to form the leads. In some embodiments, the region 1030 of the leadframe corresponding to the die attach pad of the leadframe is also exposed. The top surfaces 1020 a , side surfaces 1020 b , and region 1030 are plated with a plating material. In some embodiments, the plating material on the surfaces is a material configured not to react with oxygen. In some embodiments, the plating material is a metallic material. In some embodiments, the plating material is tin. Other materials that can be used as the plating material include, but are not limited to, silver, gold, nickel-gold, nickel-palladium, and nickel-palladium-gold. In some embodiments, the side surfaces of the semiconductor package 1000 have a first portion 1010 b , formed from a first partial singulation blade, and a second portion 1015 b , formed from a second partial singulation blade that is thicker than the first partial singulation blade. As a result of the second singulation blade being thicker than the first singulation blade, a step is formed on the side of the semiconductor package 1000 . As mentioned above, semiconductor package 1000 is almost identical to semiconductor package 900 , except for the height of the step on its side surface. The first portion 910 b and the second portion 915 b of the side surfaces in FIG. 9 are substantially equal in height, whereas the first portion 1010 b of the side surface in FIGS. 10A-B is substantially smaller in height than the second portion 1015 b of the side surfaces in FIGS. 10A-B . FIGS. 11A-H illustrate different stages of a singulation and plating process using partial cutting with a partial bevel-edged blade in accordance with some embodiments of the present invention. In FIG. 11A , a plurality of semiconductor dies 1120 are each coupled to a surface of the same leadframe 1110 (e.g., a leadframe strip). In a preferred embodiment, each of the semiconductor dies 1120 is attached to a die attach pad on the leadframe 1110 . The leadframe 1110 comprises a side surface 1105 that extends between a bottom surface 1115 of the leadframe and the top surface of the leadframe (i.e., the surface to which the semiconductor dies are attached). It is contemplated that the semiconductor dies 1120 can be coupled to the leadframe 1110 in a variety of different ways, including, but not limited to, using soldering flux. The semiconductor dies 1120 are wire bonded to the leadframe 1110 using wires 1130 . It is contemplated that a variety of different types of materials can be used to form the bonding wires 1130 , including, but not limited to, aluminum, copper, and gold. In FIG. 11B , a molding process is performed to encase the semiconductor dies 1120 , the leadframe 1110 , and the bonding wires 1130 in a molding compound 1140 . In FIG. 11C , a plating process is performed to plate the bottom surface 1115 with a plating material 1150 . In a preferred embodiment, the plating material 1150 is a material configured not to react with oxygen. In some embodiments, the plating material 1150 is a metallic material. In some embodiments, the plating material 1150 is tin. Other materials that can be used as the plating material 1150 include, but are not limited to, silver, gold, nickel-gold, nickel-palladium, and nickel-palladium-gold. In FIG. 11D , a partial singulation process is performed on the leadframe strip 1110 . In a preferred embodiment, blades 1160 are used to partially singulate the semiconductor packages. For example, in some embodiments, the blades 1160 cut through the entire leadframe 1110 , but do not pass through all of the molding compound 1140 , thereby forming side surface 1142 of the molding compound between neighboring semiconductor dies 1120 , but still leaving the individual semiconductor packages attached to one another. In FIG. 11E , the side surfaces 1105 of the leads between neighboring semiconductor dies 1120 are exposed as a result of the partial singulation process. The singulated semiconductor packages can now be loaded to another plating process. In FIG. 11F , the exposed side surfaces 1105 of the leads are plated with a plating material 1155 . As discussed above, the plating material 1155 is preferably a material configured not to react with oxygen. In some embodiments, the plating material 1155 is a metallic material. In some embodiments, the plating material 1155 is tin. Other materials that can be used as the plating material 1150 include, but are not limited to, silver, gold, and nickel-gold. In FIG. 11G , another partial singulation process is performed on the leadframe strip 1110 in order to complete the singulation of the semiconductor packages. In a preferred embodiment, blades 1162 are used to singulate the semiconductor packages. In some embodiments, the blades 1162 of have a different shape than the blades 1160 of the first partial singulation process in FIG. 11D . In some embodiments, the blades 1162 have a beveled edge. FIG. 11H shows the finished individual semiconductor packages 1100 , similar to the semiconductor package 200 in FIG. 2 . Each semiconductor package 1100 has a semiconductor die 1120 and a leadframe 1110 at least partially encased in the molding compound 1140 , with the leads of each leadframe 1110 being accessible to electrical coupling via the plating material 1150 and 1155 over the portions of the leads that are exposed from the molding compound 1140 . Each semiconductor package 1100 has side surfaces that are formed from the molding compound 1140 . FIG. 11H shows the side surfaces of semiconductor package 1100 having a first portion 1142 , formed from the first partial singulation blade 1160 , and a second portion 1144 , formed from the second partial singulation blade 1162 . A beveled surface 1146 , formed from the beveled edge of the second partial singulation blade 1162 , extends from the first portion 1142 to the second portion 1144 . FIGS. 12A-G illustrate different stages of another singulation and plating process using partial cutting with a partial bevel-edged blade in accordance with some embodiments of the present invention. In FIG. 12A , a plurality of semiconductor dies 1220 are each coupled to a surface of the same leadframe 1210 (e.g., a leadframe strip). In a preferred embodiment, each of the semiconductor dies 1220 is attached to a die attach pad on the leadframe 1210 . The leadframe 1210 comprises a side surface 1205 that extends between a bottom surface 1215 of the leadframe and the top surface of the leadframe (i.e., the surface to which the semiconductor dies are attached). It is contemplated that the semiconductor dies 1220 can be coupled to the leadframe 1210 in a variety of different ways, including, but not limited to, using soldering flux. The semiconductor dies 1220 are wire bonded to the leadframe 1210 using wires 1230 . It is contemplated that a variety of different types of materials can be used to form the bonding wires 1230 , including, but not limited to, aluminum, copper, and gold. In FIG. 12B , a molding process is performed to encase the semiconductor dies 1220 , the leadframe 1210 , and the bonding wires 1230 in a molding compound 1240 . In FIG. 12C , a partial singulation process is performed on the leadframe strip 1210 . In a preferred embodiment, blades 1260 are used to partially singulate the semiconductor packages. For example, in some embodiments, the blades 1260 cut through the entire leadframe 1210 , but do not pass through all of the molding compound 1240 , thereby forming side surface 1242 of the molding compound between neighboring semiconductor dies 1220 , but still leaving the individual semiconductor packages attached to one another. In FIG. 12D , the side surfaces 1205 of the leads between neighboring semiconductor dies 1220 are exposed as a result of the partial singulation process. The singulated semiconductor packages can now be loaded to a plating process. In FIG. 12E , the bottom surfaces 1215 and the exposed side surfaces 1205 of the leads are plated with a plating material 1250 and 1255 , respectively. As discussed above, the plating material is preferably a material configured not to react with oxygen. In some embodiments, the plating material is a metallic material. In some embodiments, the plating material is tin. Other materials that can be used as the plating material include, but are not limited to, silver, gold, nickel-gold, nickel-palladium, and nickel-palladium-gold. In FIG. 12F , another partial singulation process is performed on the leadframe strip 1210 in order to complete the singulation of the semiconductor packages. In a preferred embodiment, blades 1262 are used to singulate the semiconductor packages. In some embodiments, the blades 1262 have a different shape than the blades 1260 of the first partial singulation process in FIG. 12C . Preferably, the blades 1262 are beveled. In some embodiments, the blades 1262 have a different thickness than the blades 1260 . In some embodiments, the blades 1262 have a greater thickness than the blades 1260 . FIG. 12G shows the finished individual semiconductor packages 1200 , similar to the semiconductor package 200 in FIG. 2 . Each semiconductor package 1200 has a semiconductor die 1220 and a leadframe 1210 at least partially encased in the molding compound 1240 , with the leads of each leadframe 1210 being accessible to electrical coupling via the plating material 1250 and 1255 over the portions of the leads that are exposed from the molding compound 1240 . Each semiconductor package 1200 has side surfaces that are formed from the molding compound 1240 . FIG. 12G shows the side surfaces of semiconductor package 1200 having a first portion 1242 , formed from the first partial singulation blade 1260 , and a second portion 1244 , formed from the second partial singulation blade 1262 . A beveled surface 1246 , formed from the beveled edge of the second partial singulation blade 1262 , extends from the first portion 1242 to the second portion 1244 . FIG. 13 is a cross-sectional perspective view of a partial cutting of a semiconductor package 1300 with both partial and full bevel-edged blade assemblies 1360 a and 1360 b , respectively, in accordance with some embodiments of the present invention. In FIG. 13 , semiconductor package 1300 comprises a semiconductor die and a leadframe encased within a molding compound, with the side surface of leads 1320 b being exposed from the molding compound. During the partial singulation cutting of the semiconductor package 1300 , a cutting blade cuts through the molding compound and/or the leadframe. In FIG. 13 , the cutting blade is shown cutting through the bottom surface 1310 c of the semiconductor package 1300 , which is positioned with its bottom surface 1310 c facing upwards. In some embodiments, a partially or fully bevel-edged blade can be used to form a beveled side surface 1315 b of the semiconductor package 1300 . In some embodiments, the side surface of the semiconductor package 1300 comprises a non-beveled side surface 1310 b and the beveled side surface 1315 b . In some embodiments, the non-beveled side surface 1310 b is formed from a straight-edged blade, such as blade 860 shown in FIG. 8 , and the beveled side surface 1315 b is formed from a bevel-edged blade, which can either be partially beveled, such as blade 1362 a of blade assembly 1360 a , or fully beveled, such as blade 1362 b of blade assembly 1360 b . In some embodiments, the partially bevel-edged blade 1362 a and the fully bevel-edged blade 1362 b extend from shanks 1364 a and 1364 b , respectively. In some embodiments, the shanks 1364 a and 1364 b are used to hold and manipulate the blades 1362 a and 1362 b , respectively. As seen in FIG. 13 , partially beveled blade 1362 a comprises a non-beveled portion extending from the shank 1364 a to a beveled portion, while fully beveled blade 1362 b is tapered all the way from the shank 1364 b to its end. FIGS. 14A and 14B illustrate perspective views of the bottom and top of a semiconductor package 1400 having a beveled side surface formed with a partial bevel-edged blade in accordance with some embodiments of the present invention. Semiconductor package 1400 is almost identical to semiconductor package 900 , except that semiconductor package 1400 has a beveled side surface 1414 b . Semiconductor package 1400 has a top surface 1410 a , a bottom surface 1410 c opposite the top surface 1410 a , and side surfaces between top surface 1410 a and bottom surface 1410 c , preferably all formed by a molding compound. A leadframe is encased in the molding compound, with the top surfaces 1420 a and side surfaces 1420 b of its leads being exposed. In some embodiments, the leads are copper. However, it is contemplated that other materials besides copper can be used to form the leads. In some embodiments, the region 1430 of the leadframe corresponding to the die attach pad of the leadframe is also exposed. The top surfaces 1420 a , side surfaces 1420 b , and region 1430 are plated with a plating material. In some embodiments, the plating material on the surfaces is a material configured not to react with oxygen. In some embodiments, the plating material is a metallic material. In some embodiments, the plating material is tin. Other materials that can be used as the plating material include, but are not limited to, silver, gold, nickel-gold, nickel-palladium, and nickel-palladium-gold. In some embodiments, the side surfaces of the semiconductor package 1400 have a first portion 1410 b , formed from a first partial singulation blade, and a second portion 1412 b , formed from a second partial singulation blade that is thicker than the first partial singulation blade. Additionally, the second partial singulation blade is a partially bevel-edged blade, such as blade 1362 a in FIG. 13 . As a result of the second singulation blade using a partially bevel-edged blade, a beveled side surface 1414 b is formed on the side of the semiconductor package 1400 between the first portion 1410 b and the second portion 1412 b , which are non-beveled. FIGS. 15A and 15B illustrate perspective views of the bottom and top of a semiconductor package 1500 having a beveled side surface with a first height formed with a full bevel-edged blade in accordance with some embodiments of the present invention. Semiconductor package 1500 is almost identical to semiconductor package 900 , except that semiconductor package 1500 has a beveled side surface 1512 b . Semiconductor package 1500 has a top surface 1512 a , a bottom surface 1510 c opposite the top surface 1510 a , and side surfaces between top surface 1510 a and bottom surface 1510 c , preferably all formed by a molding compound. A leadframe is encased in the molding compound, with the top surfaces 1520 a and side surfaces 1520 b of its leads being exposed. In some embodiments, the leads are copper. However, it is contemplated that other materials besides copper can be used to form the leads. In some embodiments, the region 1530 of the leadframe corresponding to the die attach pad of the leadframe is also exposed. The top surfaces 1520 a , side surfaces 1520 b , and region 1530 are plated with a plating material. In some embodiments, the plating material on the surfaces is a material configured not to react with oxygen. In some embodiments, the plating material is a metallic material. In some embodiments, the plating material is tin. Other materials that can be used as the plating material include, but are not limited to, silver, gold, nickel-gold, nickel-palladium, and nickel-palladium-gold. In some embodiments, the side surfaces of the semiconductor package 1500 have a first portion 1510 b , formed from a first partial singulation blade, and a second portion 1512 b , formed from a second partial singulation blade. The first portion 1510 b is non-beveled. The second partial singulation blade is a full bevel-edged blade, such as blade 1362 b in FIG. 13 . As a result of the second singulation blade using a full bevel-edged blade, a beveled side surface 1512 b is formed on the side of the semiconductor package 1500 . FIGS. 16A and 16B illustrate perspective views of the bottom and top of a semiconductor package 1600 having a beveled side surface with a second height formed with a full bevel-edged blade in accordance with some embodiments of the present invention. Semiconductor package 1600 is almost identical to semiconductor package 1500 , except for the height of the beveled portion of its side surface. Semiconductor package 1600 has a top surface 1610 a , a bottom surface 1610 c opposite the top surface 1610 a , and side surfaces between top surface 1610 a and bottom surface 1610 c , preferably all formed by a molding compound. A leadframe is encased in the molding compound, with the top surfaces 1620 a and side surfaces 1620 b of its leads being exposed. In some embodiments, the leads are copper. However, it is contemplated that other materials besides copper can be used to form the leads. In some embodiments, the region 1630 of the leadframe corresponding to the die attach pad of the leadframe is also exposed. The top surfaces 1620 a , side surfaces 1620 b , and region 1630 are plated with a plating material. In some embodiments, the plating material on the surfaces is a material configured not to react with oxygen. In some embodiments, the plating material is a metallic material. In some embodiments, the plating material is tin. Other materials that can be used as the plating material include, but are not limited to, silver, gold, nickel-gold, nickel-palladium, and nickel-palladium-gold. In some embodiments, the side surfaces of the semiconductor package 1600 have a first portion 1610 b , formed from a first partial singulation blade, and a second portion 1612 b , formed from a second partial singulation blade. The first portion 1610 b is non-beveled. The second partial singulation blade is a full bevel-edged blade, such as blade 1362 b in FIG. 13 . As a result of the second singulation blade using a full bevel-edged blade, a beveled side surface 1612 b is formed on the side of the semiconductor package 1600 . As mentioned above, semiconductor package 1600 is almost identical to semiconductor package 1500 , except for the height of the beveled side surface. The first portion 1510 b and the beveled portion 1512 b of the side surfaces in FIGS. 15A-B are substantially equal in height, whereas the first portion 1610 b of the side surface in FIGS. 16A-B is substantially smaller in height than the second portion 1612 b of the side surfaces in FIGS. 16A-B . The variations in cutting shapes and heights discussed above and shown in the figures can be achieved by varying the shape of the cutting blade and its cutting depth. The present invention has been described in terms of specific embodiments incorporating details to facilitate the understanding of principles of construction and operation of the invention. Such reference herein to specific embodiments and details thereof is not intended to limit the scope of the claims appended hereto. It will be readily apparent to one skilled in the art that other various modifications may be made in the embodiment chosen for illustration without departing from the spirit and scope of the invention as defined by the claims.

A method of singulating semiconductor packages, the method comprising: providing a plurality of semiconductor dies coupled to a single common leadframe, wherein a molding compound at least partially encases the semiconductor dies and the leadframe; singulating the plurality of semiconductor dies, wherein the leadframe is at least partially cut between adjacent semiconductor dies, thereby forming exposed side surfaces on leads of the leadframe; and plating the exposed side surfaces of the leads with a plating material, wherein the plating material is a different material than the leads. In some embodiments, singulating the plurality of semiconductor dies comprises performing a full cut of the leadframe. In some embodiments, singulating the plurality of semiconductor dies comprises performing separate partial cuts of the leadframe.

big_patent

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The invention relates to a dual mode mobile terminal and, more particularly, to a connecting method for selectively connecting to a wireless wide area network and a wireless local network. [0003] 2. Description of the Prior Art [0004] In recent years, new communication technologies are developed and customers can select different kinds of personal communication systems to use voice/data services. The communication systems are, for example, GSM/WCDMA/CDMA2000 wireless wide area networks (WWAN) and voice service over wireless local area networks (WLAN). [0005] Fixed Mobile Convergence (FMC) is developed by integrating both WWAN and WLAN in one communication system. The connection of a FMC mobile terminal can be switched between WWAN and WLAN when the mobile terminal determines one of the networks is suitable for communicating. The mobile terminal having two wireless modules, for example, a GSM module and a WiFi module. When the signal level of the WLAN is above a first threshold, the mobile terminal accesses the WLAN through the WiFi module. When the mobile terminal is leaving the coverage of the WLAN and the signal level of WLAN drops below a second threshold, the mobile terminal switched to the WWAN and communicating through the GSM module. [0006] However, when the mobile terminal turns the GSM module and the WiFi module on at the same time for selectively communicates the WWAN and the WLAN, it is power consuming. To overcome the above drawbacks, the GSM module is turned off and WiFi module turned on, when the mobile terminal only accesses the WLAN. Once the signal level received from the WLAN becomes low, the mobile terminal turns the GSM module on for connecting the WWAN for keeping the connection. The GSM module begins to scan the neighboring base stations. However, because of different communication environments, occasionally, it is possible that the GSM module needs a longer scanning/processing time that may cause some of the connections dropped, especially when the user is using the mobile terminal for voice communication. [0007] In order to solve the aforesaid problems, this invention want to provide a method and a system to make the mobile terminal switches from the WLAN to the WWAN in time to avoid dropping or delaying the connections. SUMMARY OF THE INVENTION [0008] It is therefore an object of the invention to provide a mobile terminal selectively connecting a wireless wide area network and a wireless local area network. The wireless local area network gathers the information of neighboring base stations from an access point. The mobile terminal receives the information when the mobile terminal connects the wireless local area network. The mobile terminal can skip some of the connection setup time when the mobile terminal starts to connect the wireless wide area network by using the information. [0009] According to the invention, a mobile terminal is able to select one of a wireless wide area network (WWAN) or a wireless local area network (WLAN) for voice/data communicating. The WWAN, for example a GSM network, contains a plurality of the first base stations. Each coverage of the first base station is about 2 to 10 km in a normal GSM system. The WLAN contains at least one second base station for gathering a service information of the first base stations. The service information includes signal strength, channel information and base station identity codes of the first base stations. The service information is broadcasted by the first base stations. The second base station of WLAN can be an access point. In this invention, the access point has a GSM module for scanning the broadcasting information of the neighboring first base station. The access point transmits the information to the mobile terminal when the mobile terminal is connecting the access point. [0010] The mobile terminal has a first network module and a second network module. The first network module, for example, is a GSM module for connecting the WWAN. The second network module, for example, is a WiFi module for connecting the second base station and receiving the service information from the WLAN; [0011] In this invention, the coverage of the WWAN and the coverage of the second base station are overlapping. When the mobile terminal connects to the second base station in the coverage of the second base station, the first network module turns off and the second network module turns on. When the user uses the mobile terminal at his house, the mobile terminal connects the WLAN for communication services. When the user leaves out his house and carries the mobile terminal with him, the signal level of a transmitting signal of the second base station received by the mobile terminal becomes low. When the signal level of a transmitting signal is lower than a first threshold, the mobile terminal turns the first network module on and the first network module selects one of the first base stations as a serving base station according to the service information to connect the WWAN. In other words, some initial scanning procedures of the first network module are made by the second base station and recorded in the service information. The signal strength of the serving base station is the highest one among signal strength of the first base stations. As the first network module skips some initial scanning procedures that the access point made before, it may accelerate the connecting procedures for the first network module. When the user comes back to his house, the signal level of a transmitting signal from the second base station is higher than a second threshold, the first module turns off. The mobile terminal connects the second base station for further communicating. [0012] It is still possible that the first wireless module fails to connect the serving base station by using the service information because of the environments rapidly changing. In that case, the first wireless module starts scanning the first base stations according to the channel information of the service information, i.e. scanning all channel information of the first base stations. In case, the first wireless module still fails to connect the serving base station, it needs to start a conventional connecting procedure. [0013] This invention provide a method for a mobile terminal to select a serving base station of a wireless wide area network (WWAN) in a communication system. The communication system contains the wireless wide area network (WWAN) and a wireless local area network (WLAN) and the mobile terminal. The WWAN has a plurality of first base stations. The WLAN has a second base station for gathering a service information of the first base stations. The mobile terminal has a first wireless module for connecting the WWAN and a second wireless module for connecting the second base station. Normally, when the mobile terminal connects the WLAN, the second wireless module is on and the first wireless module is off. The steps of the method are: (a) turning the first wireless module on according to a first rule; (b) the second wireless module receiving the service information from the second base station; (c) the second wireless module transmitting the service information to the first wireless module; and (d) the first network module selecting one of the first base stations as a serving base station according to the service information to connect the WWAN. [0014] In step (b), the second network module sends a requesting signal to the second base station. And then, the second base station gathers the service information of the first base station. The second base station sends the service information to the second network module. The service information contains signal strength, channel information and base station identity codes of the first base stations. [0015] In case, the first wireless module failed to connect the serving base station by using the service information, the first wireless module starts scanning the first base stations according to the channel information of the service information. [0016] The advantage and spirit of the invention may be understood by the following recitations together with the appended drawings. BRIEF DESCRIPTION OF THE APPENDED DRAWINGS [0017] FIG. 1 is a functional block diagram illustrating the system contains the mobile terminal, WWAN and WLAN. [0018] FIG. 2 is a flow diagram generally showing one embodiment of the method for the mobile terminal selecting a serving base station. [0019] FIG. 3 is a flow diagram generally showing one embodiment for the mobile terminal receiving the service information from the second base station. DETAILED DESCRIPTION OF THE INVENTION [0020] The present invention now will be described more fully hereinafter with reference to the accompanying drawings, which form a part hereof, and which show, by way of illustration, specific exemplary embodiments by which the invention may be practiced. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Among other things, the present invention may be embodied as methods or devices. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. The following detailed description is, therefore, not to be taken in a limiting sense. [0021] FIG. 1 illustrates a function block diagram of one embodiment of a communication system 1 . The communication system 1 contains a mobile terminal 10 , a wireless wide area network (WWAN) 12 and a wireless local network (WLAN) 14 . The WWAN 12 can be GSM, GPRS, WCDMA or 4 G network based on LTE. The WLAN 14 can be WiMax, WiFi or Bluetooth network. [0022] The WWAN 12 and The WLAN 14 can be integrated into a FMC (fixed-mobile convergence) system and the mobile terminal 10 is adapted for the FMC system accordingly. However the mobile terminal 10 can be a dual mode mobile terminal for using in the WLAN 14 and the WWAN 12 which are independent. [0023] The WWAN 12 contains the first base stations 122 a, 122 b and 122 c. The WLAN 14 contains a second base station 142 . The second base station 142 can be an access point with a third network module 1420 for gathering the service information of the first base stations. The service information contains signal strength, channel information and base station identity codes of the first base stations. The third network module 1420 is a radio frequency receiver for demodulating/decoding the broadcasting signals of the first base stations to obtain the above service information. [0024] The mobile terminal 10 contains a first wireless module 102 and a second wireless module 104 . The first wireless module 102 can be selectively turning on and turning off for connecting the WWAN 12 . The second wireless module 104 can accessing the WLAN 14 through the second base station 142 and receiving the service information from the second base station. [0025] When the first wireless network module 102 turning off and the second wireless network 104 turning on, the mobile terminal 10 may turn on/off the first wireless network module 102 according a first rules. The first rules are, for example, detecting the signal level of the transmitting signal transmitted from the second base station 142 to the second wireless module 104 is smaller than a first predetermined threshold or the signal level of the transmitting signal is continuously smaller than a second predetermined threshold for a time period, turning on the first wireless network module 102 . The first rules can also be the signal level of the transmitting signal from the second base station 142 to the second wireless module 104 is greater than a third predetermined threshold, turning off the first wireless network module 102 and accessing the second base station 142 by the second wireless network 104 . It is also possible to build other new first rules, for example, the user can set a timer for turning on/off the first wireless network module 102 etc. [0026] When the first wireless network module 102 turns on, the first wireless network module 102 selecting a serving base station from the base stations 122 a , 122 b and 122 c according to the service information. In this embodiment, the third network module 1420 gathering the service information of the first base stations and determining the first base station being the serving base station with the strongest signal strength among the first base stations. The mobile terminal 10 can access the WWAN 12 by the serving base station 122 c. [0027] Alternatively, the first wireless network module 102 may also select a specific mobile phone operator according the Base Station Identity Code (BSIC) of the service information. [0028] When the first wireless network module 102 fails to build up a connection to the serving base station by using the service information. The first wireless network module 102 can scan the frequency channels by using the service information. If it fails again, it may start an all channels scanning procedures. [0029] FIG. 2 illustrates a flow diagram showing one embodiment of the method for the mobile terminal selecting a serving base station. The method is adopted to the system shown on the FIG. 1 . At block S 50 , when the first wireless network module turning off and the second wireless network turning on, the mobile terminal can turn on/off the first wireless network module according a first rule. The first rules is, for example, the transmitting signal transmitted from the second base station to the second wireless module is smaller than a first predetermined threshold, turning on the first wireless network module 102 . [0030] At block S 52 , the second wireless network module receives a service information from the second base station. The service information is related to the broadcasting information of the neighboring first base station. Block S 52 may be processing before or after block S 50 . It is also possible that the second wireless network module continuously (or periodically) accesses the service information from the second base station. The service information contains signal strength, channel information and base station identity codes of the first base stations. [0031] At block S 54 , the second wireless network module passes the service information to the first wireless network module. At block S 56 , the first wireless network module selects a serving base station from the first base stations according the service information for accessing the WWAN. In this embodiment, the second base station gathering the service information of the first base stations and determining one of the first base station being the serving base station with the strongest signal strength among the first base stations. Alternatively, the first wireless network module may also select a specific mobile phone operator according the Base Station Identity Code (BSIC) of the service information. [0032] When the first wireless network module fails to build up a connection to the serving base station by using the service information. The first wireless network module can scan the frequency channels by using the service information. If it fails again, it may start an all channels scanning procedure. [0033] FIG. 3 illustrates a flow diagram showing one embodiment for the mobile terminal 10 selecting a serving base station. When the second wireless network module 104 find the rule is active, for example, the signal level of the transmitting signal from the second base station 142 to the second wireless module 104 is smaller than a first predetermined threshold, turning the first wireless network module 102 on. At block S 70 , the second wireless network module 104 start a procedure for waking up the first wireless network module 102 . [0034] In the mean time, the second wireless network module 104 transmitting a request signal to the second base station 142 according as the rule is active. The second base station 142 triggers the third wireless network module 1420 receiving the radio signals of the neighboring first base stations for gathering a service information. At block 72 , the third wireless network module 1420 may continuously or periodically scan and store the service information. [0035] When the third wireless network module 1420 gets the service information, the second base station sends the service information the second wireless network module 104 . Then, the second wireless network module 104 passes the service information to the first wireless network module 102 . At block S 74 , the first wireless network module 102 selects a serving base station from the first base stations according the service information. [0036] When the first wireless network module 102 connects the serving base station and accesses the WWAN, the first wireless network module 102 sends an confirmation signal to the second wireless network module 104 . At block S 76 , the second wireless network module 104 begins a switching procedure from the WLAN to WWAN, at block S 78 . [0037] In this invention, no matter what status of the mobile terminal is, for example “call set up”, “idle” or even the mobile terminal is in a calling status, the mobile terminal can use this invention for switching the connecting from WLAN to WWAN. [0038] Although the present invention has been described in its preferred embodiments, it is not intended to limit the invention to the precise embodiments disclosed herein. Those who are skilled in this technology can still make various alterations and modifications without departing from the scope and spirit of this invention. Therefore, the scope of the present invention shall be defined and protected by the following claims and their equivalents.

The invention provides a mobile terminal having a first network module for connecting to a wireless wide area network (WWAN) and a second network module for connecting to a wireless local area network (WLAN). The WWAN includes a plurality of first base stations. The WLAN includes a second base station. The second base station obtains service information related to the first base stations and sends the service information to the second network module. When the first network module is turned off and the second network module is turned on, the a mobile terminal is leaving the service area of the WLAN. The first network module turns on and chooses one of the first base stations to be a serving base station according to the saved service information for quickly accessing the WWAN.

big_patent

This is a division of application Ser. No. 797,193, filed Apr. 16, 1977 now U.S. Pat. No. 4,183,074. BACKGROUND OF THE INVENTION This invention relates generally to the production of multilayered components, and more particularly concerns process and apparatus to produce multilayered electrical components; additionally, the products produced by the process are part of the invention. Conventional processes for producing commercial multilayer capacitors employ the following steps: 1. Casting a ceramic slip by use of a doctor blade to form a green, dried ceramic film of 0.001" to 0.002" thickness; 2. Printing a registered matrix of metal pigmented inks to form the electrodes of the finished capacitor on the ceramic film; 3. Stacking a number of the registered electrode matrices in a cavity and laminating the stack of printed ceramic sheets with pressure and heat to form a compacted structure; 4. Cutting the compacted structure as by use of a guillotine type cutter. The number of parts generated is determined by the number of electrodes in the printing matrix; 5. Thermal processing consists of a drying and bake out cycle to eliminate the organic components from the green parts, followed by a firing cycle to 2,000° F. to 2,300° F. to form the final ceramic structure. 6. Metallizing the ends of each individual capacitor element is necessary to achieve the desired electronic configuration. This is accomplished by applying a small amount of a fritted silver paint to each end of the ceramic capacitor element. After both ends are dried, the parts are fired to form metallic surfaces by which the appropriate individual electrodes within the ceramic are interconnected, and also by which the finished part may be connected to an electronic circuit. 7. Testing for the various electrical parameters completes the manufacturing process. The controls necessary to achieve a satisfactory yield of capacitors of a specified value are indicated by the mathematical relationships related in the design equation: ##EQU1## where, C=capacitance of the device n=number of active layers k=dielectric constant of ceramic film A=active area of an electrode (fired) d=fired thickness of the dielectric film (in thousandth of an inch) To achieve a given value for capacitance C one must accurately control values of these parameters, as follows: (d) Dielectric thickness (typically 0.0013"±0.0001"), and (k) Dielectric constant. Control of this parameter is not only related to "lots" (i.e. differently fired groups) but also requires a very carefully controlled firing profile for consistant results. "Lot" k values are statistically determined before releasing material to production. A number of ceramic formulations are used, each with its own unique configuration of electrical parameters. They usually are referred to as "bodies" i.e. k1200 body would be a ceramic whose k is 1200. (A) The active area of the electrode. In this regard, the electrode configuration is usually a function of mechanical constraints since it sets the size of the capacitor. Controls relating to the electrode consist of using the lowest cost precious metal electrode alloy consistent with the processing temperature and body chemistry, and controlling the electrode thickness. In this regard, changes in thickness cause a second order effect on capacitance. Also, if the electrode material is too thin as applied, areas of the electrode may be non-conductive and the effective area A will be lowered. (n) Number of active layers is important, in that once the size of the capacitor (length and width) has been set by space available, and the dielectric type and thickness are chosen as a function of the electrical circuit requirements, the number of layers (n) can be adjusted to achieve the design capacitance. Clearly, there are limits to the least and most capacitance available. The upper limit of "n" for a given part type is somewhere around 40 layers, since yield of good parts starts declining rapidly beyond that. Many parts with more layers are sold however, since high capacitance coupled with small size of a part is a premium condition and commands higher prices. It is difficult to maintain uniform, undistorted internal structures in these high layer parts because of the green ceramic density variations introduced in the manufacturing process. These result in shrinkage variations upon firing, which produce material distortions appearing as delaminations of the layered structure of the capacitor. This is the most serious mechanical defect which results from conventional production of multilayer capacitors, and one for which there is no non-destructive test available. If a production lot is sampled by making petrographic tests, and it is found that delaminations are occuring above a certain percentage (it varies as a function of end use), the whole lot must be scrapped. SUMMARY OF THE INVENTION It is a major object of the invention to provide a new process which greatly simplifies the manufacture of multilayered components, as for example by elimination of steps 4 and 6 above (these being the most costly from the standpoint of labor involved). Basically, the process includes the following steps: (a) providing a first electrode and a first electrical component and locating the electrode in a recess formed by the component to produce a first laminate sub-assembly, (b) providing a second electrode and a second electrical component and locating the electrode in a recess formed by the second component to produce a second laminate sub-assembly, and (c) locating said two sub-assemblies in mutually stacked relation, thereby to form a resultant assembly. As will appear, multiple first electrodes and first components may be formed on a first decal to produce first laminate sub-assemblies; multiple second electrodes and second components may be formed on a second decal to produce second laminate sub-assemblies; and the decals may be manipulated to remove first or type A sub-assemblies onto a setter, to remove the second or type B sub-assemblies to stack precisely on the A sub-assemblies, and this may be repeated to build-up stacks of desired numbers of electrodes, thereby to form assemblies in the form of capacitors, coils, resistances, or combinations thereof. Additional objects include the provision of methods to interconnect electrodes in stacked sub-assemblies; to locate sub-assemblies in precise registered relation; to build-up stacks with covering components at upper and lower ends of the stacks; and to achieve fabrication of such assemblies of many different sizes at very low cost and at high production rates. Further objects include the provision of apparatus or tooling to enable such fabrication, and the provision of the resultant sub-assemblies and assemblies, themselves. These and other objects and advantages of the invention, as well as the details of illustrative embodiments, will be more fully understood from the following description and drawings, in which: DRAWING DESCRIPTION FIG. 1 is a flow diagram; FIG. 2 is a plan view of a prepared decal; FIG. 3 is a plan view of the FIG. 2 decal with screen printed electrodes thereon; FIG. 4 is a plan view of the FIG. 3 composite with "A type" electrical components screen printed on the electrodes and decal; FIG. 5 is a plan view like FIG. 4 but with "B type" components screen printed on electrodes and on the decal; FIG. 6 is a plan view like FIG. 4 but with "C type" components printed directly on the decal, i.e. with no electrodes; FIG. 7 is an enlarged plan view of an "A type" component and electrode composite; FIG. 8 is a side view of the FIG. 7 composite; FIG. 9 is an enlarged plan view of a "B type" component and electrode composite; FIG. 10 is a side view of the FIG. 9 composite; FIG. 11 is an end view of the FIG. 9 composite; FIG. 12 is an enlarged plan view of a "C type" component; FIG. 13 is a side view of the FIG. 12 component; FIG. 14 is a schematic elevational view of a screening process to deposite electrodes on a decal; FIG. 15 is a schematic elevational view of a screening process to deposite electrical components, on the electrodes previously deposited as in FIG. 14; FIG. 16 is a schematic elevational view of the FIG. 15 composites after inversion on to a support, and showing peeling of the decal; FIG. 17 is a view like FIG. 16 but showing both A and B type composites, one stacked on the other, and a decal for the upper composites being peeled away; FIG. 18 is a side elevational view showing a completed multi-layered electrical assembly prior to firing; FIG. 18a is like FIG. 18, but shows a completed capacitor; FIG. 19 is a view like FIG. 7 showing a varied, i.e. A' composite; FIG. 20 is an end view of the A' composite of FIG. 19; FIG. 21 is a view like FIG. 9 showing a varied, i.e. B' type composite; FIG. 22 is an end view of the FIG. 21 composite; FIG. 23 is a view like FIG. 21, showing a varied, i.e. C 1 type composite; FIG. 24 is an end view of the C 1 composite; FIG. 25 is a view like FIG. 23 showing a further varied, i.e. C 2 type composite; FIG. 26 is a view like FIG. 12 showing a blank component; FIG. 27 is an enlarged side elevation of a stack of composites as seen in FIGS. 19-26; FIG. 28 is a perspective view of a spiral (left handed) electrode pattern; FIG. 29 is an elevational view of a composite which incorporates the FIG. 28 electrode; FIG. 30 is a perspective view of a spiral (right handed) electrode pattern; FIG. 31 is an elevational view of a composite which incorporates the FIG. 30 electrode; FIG. 32 is an elevational view of an assembly which incorporates the FIGS. 29 and 31 composites, in alternating relation, to form a coil; and FIG. 33 is an elevation showing a combination of assemblies. DETAILED DESCRIPTION Referring first to FIGS. 1 and 2, the process contemplates the provision of carriers such as flexible decals 10, which are initially prepared. Such preparation, indicated at 13, may advantageously include punching holes 11 through the rectangular decal sheets, as for example proximate to opposite corners 10a and 10b. Such holes closely fit guide posts, as are better seen at 12 in FIGS. 14-17, in order to guide the decals into accurate registration upon assembly of electrode and electrical component composites. Typical transfer decals are formed by 6 inch by 6 inch square sheets of MYLAR plastic material. The surface of the decal is further prepared by application of a thin coating of a transfer release agent 14 as for example wax. Such agent is somewhat tacky at room temperature to retain the composites for transfer, and may easily release them in response to heating of the wax. Next, multiple first electrodes are provided in spaced apart and supported relation on a first carrier, i.e. a first decal 10a. This step is indicated at 16 in FIG. 1, and FIG. 3 shows rows and columns of such electrodes 17 on the decal. Referring to FIG. 14, this step may be carried out by screening a fluid mix which includes the electrode material onto the decal. Note the screen 18, suitably supported at 19, and a template 20 on the screen with openings 21 directly over the locations at which the mix is deposited onto decal as electrodes 17. A squeegee blade 23 may be passed over the template, as shown, to force fluid mix 22, through the openings 21 onto the screen and onto the decal. Note guide posts 12 passed through registration holes in the decal, screen and template. The electrodes may have rectangular shape, as shown, or any other desired shape. Electrode liquid mixes are known as "inks", and representative inks are identified as Conductive Inks produced by DuPont, Selrex, Cladan Inc., and others. Curing of the electrodes to said form may be accelerated under mild heating as indicated at 26 in FIG. 1. In addition, to the use of air drying inks for both the electrode and dielectric functions, the use of Electro-Therm inks is included. This technique enables use of an "ink" or transfer mechanism which is a solid at room temperature but is of an ink-like consistancy at temperatures 10° to 100° F. above ambient. Upon being "screened" or printed onto the substrate using a heated screen or template, the ink freezes to a "dry" or solid state and may be immediately processed to the next operational step. Such a material is a product of the Ferro Corp., and is marketed under the name "Electro-Therm Inks". Next, and as shown at 27 in FIG. 1, multiple electrical components A are deposited in the formed electrodes 17 on certain decals to produce first laminate sub-assemblies, this step also appearing in FIG. 4. Likewise, components B are deposited on formed electrodes on other decals as indicated at 28 in FIG. 1 and in FIG. 5, to produce second laminate sub-assemblies. Typically, and extending the description to FIG. 15, the source of the components consists of a comminuted dielectric material such as a ceramic, in a liquid carrier, supplied at 29. A squeegee blade 131 is passed over a template 32 to urge the liquid mix through template openings 33 and through a screen 34 for deposition on the electrodes. It will be noted that the deposition of the mix is onto part, but not all, of each electrode, and also onto the decal; for example, the electrode may protrude at one end of the deposited material A, for example, and the material A deposited on the decal at the opposite end of the electrode. This is also clear from FIGS. 7 and 8 wherein an electrode lamination 17 is shown locally protruding at 17a endwise from the component A lamination, the latter forming a three-side recess 30 in which the remainder of the electrode is received. The component A also extends at the end of the electrode, i.e. at 31, for purposes as will appear. Similarly, in FIGS. 9-11, the component B forms a recess 30 in which another electrode 17 is received, and from which the electrode protrudes at 17b. FIGS. 12 and 13 illustrate a blank component C of a size corresponding to the like sizes of components A and B, so that they may be stacked as in FIGS. 1 and 18. Step 35 in FIG. 1 indicates the screen formation of C component, also seen in FIG. 6, A, B and C components, in the FIGS. 4-6 showings, have corresponding row and column orientation, in the same spacial relation to decal corner openings 11, for later precision registration of the decals and components. The components A, B and C are allowed to cure, i.e. solidify, on the decals, as for example at room temperature, or more quickly under slight heat application (as for example by infra-red lamp heating). During such curing, the solvent or liquid carrier evaporates, allowing the component particles and resin binder to coagulate. Examples of such component mixes are those known in the trade as dielectric pastes, and are products of such companies as E. I. DuPont, and Selrex. Finally, the sub-assemblies as represented in FIGS. 4 and 5, and also FIG. 6, are brought into mutually stacked relation, thereby to form resultant assemblies. To this end, the carriers or decals are displaced to effect precision registration of the sub-assemblies, and the carriers are suitably removed, as by heat application and peeling away from the sub-assemblies. FIG. 16 shows sub-assemblies that embody component material B inverted and placed onto a plate 40, with predetermined precision location as effected by placement of decal corner openings 11 onto guide posts 12a. Slight heat application, as by lamp 41, melts the tacky wax on the decal, which held the sub-assemblies thereto during manipulation of the decal, and allowing peel-away of the decal. If necessary, a wax coating on the surface of plate 40 may be used to hold the sub-assemblies in position. Thereafter, FIG. 17 shows precision stacking of sub-assemblies embodying components A onto the sub-assemblies embodying components B, by inversion and placement of decal 10b into the position shown, with corner holes on posts 12a. Peel-away of the decal is also shown. In this manner, a built-up stack or assembly as shown at 44 in FIG. 18 may quickly be realized. Note that the stack is formed with tabs of successive electrodes in the stack exposed at opposite ends of the stack. No large laminating force, i.e. to compress the stack, is required because the metal electrode in each sub-assembly is flush with its associated component or dielectric surface, as explained above. This then obviates or prevents density distortions which in the past have led to serious delamination problems. FIGS. 17 and 18 also show the stacks on a setter 40 upon which drying and firing of the stacks takes place. This eliminates hand loading which was previously required to maintain the parts in separated relation so as not to fuse together. The exposed electrode tabs at each end of the stack melt and fuse together during the bake-out cycle, whereby alternate electrodes are electrically joined, at 17a' and 17b' to form a capacitor, as seen in FIG. 18a. Many different and more complex configurations can be made in this manner, and in both large, medium and small sizes. The preceding drawing descriptions have concerned quite simple electrodes for conceptual purposes. In actual practice, a more complicated electrode configuration can be used, as shown in FIGS. 19-27. In FIGS. 19 and 20 the flat electrode 51 has T shape or outline, the "stem" 51a of the T located inwardly of the outer sides 52a and end 52b of ceramic lamination or component 52. Note that the electrode is "sunk" in a recess 52d formed by the component 52 so that the underside 51c of the electrode is flush with the underside 52c of the component 52. The cross-bar 51d of the T-shaped electrode protrudes at the opposite end of the component 52, and also protrudes laterally beyond the laterally opposite sides 52a. This sub-assembly is designated "A". A similar "B" sub-assembly is shown in FIGS. 21 and 22, the difference being that the A and B electrode cross-bars are located at opposite ends of the ceramic components. The C 1 sub-assembly of FIGS. 23 and 24 differs in that the electrode material 53 overlaps and stands out above the end surface of the ceramic component 54. Also, it protrudes endwise at 53a, as seen in FIG. 27. This C 1 sub-assembly is adapted to form an upper "cover" in the stack formed as shown in FIG. 27. The FIG. 25 C 2 sub-assembly again differs in that the electrode material 55 is "sunk" in a recess 57 formed by ceramic component 56, as seen in FIG. 27; also the electrode material protrudes endwise at 55a. C 2 forms a lower cover at the stack. FIG. 16 shows a blank ceramic component 58, and is also shown in the stack between cover C 2 and a sub-assembly A. Upon heating of the formed stack, as during firing, the protruding electrodes 53a, 51d and 55a soften and fuse together, as indicated by dotted line 59. The same thing occurs at the opposite ends of the sub-assemblies at the opposite side of the FIG. 27 stack. A multi-plate capacitor is thereby formed. Note that electrode material associated with the covers C 1 and C 2 is exposed at opposite ends of the stack. The result of using this FIG. 27 electroding configuration is the formation of the end terminations at the same time as the stack is fired. This has more significance than merely the elimination of one step. For example, the sizes of capacitors at the small end of the spectrum is limited by the difficulty of silvering the tiny pieces. This new approach allows a five-fold reduction in size, i.e. the lower size limit would be approximately 0.010" square. Also part shapes would not be limited to parallelapipeds or cylinders; i.e. literally any area shape is possible. This new process also permits all the in-process step controls that the conventional system does. It allows the inspection of both the electrode print and dielectric print for perfection and thickness before commitment to actual construction (something the spray type systems do not do). It also makes possible the use of thinner dielectric because of the electrode/dielectric configuration (embedded electrode). This makes possible the provision of a 25 volt capacitor designed to take advantage of the lower voltage (four times the capacitance for a given volume, or less than half the precious electrode material required, for the same capacitance) rather than just derating a 50 volt unit. The elimination of the cutting operation also enables the production of a more "reliable" part for high reliability requirements. One of the major concerns of recent high reliability studies performed by Hughes Aircraft Co., for the U.S. Navy is a presence of small micro cracks that can be detected on the cover plate surfaces adjacent to the silvered ends of the capacitors. They occur randomly on parts in a given lot, and are not detectible except by visual inspection magnified 400 times or more. Such cracks have proven to be the loci of a number of failure modes experienced in life testing. The source of these cracks is the cutting operation, which is eliminated by the present invention. Besides reducing the number of steps required to manufacturer parts along with the lower capital investment required, a list of advantages for the new system is as follows: 1. Smaller parts possible to fabricate. 2. Lower voltage ratings. 3. No shape limitations. 4. In process inspection enhanced. 5. Elimination of cutting stress cracks. 6. Elimination of internal delamination caused by laminating stress disturbing green density. 7. Lower labor "content" per part, i.e. less labor required to fabricate. 8. End terminations of electrodes enable provision of a variety of tab configurations with no extra process time. 9. Inventory can partially be carried in decal form, allowing for rapid response to customers. Thus, the decals can be processed as in FIGS. 16 and 17 to build-up capacitor plates and configurations, as required. 10. The invention enables provision of a line of capacitors adapted to use with semi-conductor devices, mounted on the silicon substrates such as LSI devices in watches, calculators multi processors, etc. The procedure described above, used to manufacturer multilayer ceramic capacitors, is also adaptable to a number of other electronic ceramic devices. An example would be multilayer ferrite inductors. Referring to FIGS. 28-32, the method of producing an electrical coil includes the following basic steps: (a) forming multiple laminates, each laminate including electrically conductive material in the form of a portion of a coil, and non-conducting material laminated to said electrically conductive material, and (b) stacking said laminates so that said coil portions are located for electrical interconnection to form coil structure. In FIG. 28 a left handed spiral coil "electrode" pattern 70 is initially formed on a decal 71 in the manner described above; similarly a right handed spiral coil pattern 72 is formed on a decal 73, as seen in FIG. 30. FIGS. 29 and 31 show deposition of ferrite ceramic "component" material 74 and 75 on the two coils, to form composites "A" and "B". The formation of stack 75 shown in FIG. 32 involves stacking the upright A and inverted B composites. The coils have end terminations 76 and 77 which protrude at edges of the composites as shown in FIGS. 29, 31 and 32. Similarly, the coils have terminations 76' and 77' which are spaced inwardly from the edges of the composites. Terminations 77' extend all the way through the components 75 so as to contact terminations 76'. After heating, the interengaged terminations become fused to provide a complete coil. Laborious and expensive winding of coils is thereby obviated, and many sizes of coils can be easily fabricated at low cost. Interleaving patterns would produce transformer configurations, magnetic amplifiers, saturable reactors, solenoids, memory cores, etc. Another example would be multilayer substrates which are layered ceramic structures with buried metal circuitry. Another possibility is semiconductor packages, such as the dual line configured packages. A further possibility is the fabrication of precision registers, i.e. with electrically resistive material constituting the "electrodes". For example, series connected resistors may be provided as in the FIG. 32 stack, or in another arrangement of electrodes. Series connected resistors and coils may be provided in this way, too, and capacitors may be included, all in one stack. See FIG. 33 in this regard.

A method for fabricating electrical component assemblies includes the steps: (a) providing a first electrode and a first electrical component and locating the electrode in a recess formed by the component to produce a first laminate subassembly, (b) providing a second electrode and a second electrical component and locating the electrode in a recess formed by the second component to produce a second laminate sub-assembly, and (c) locating said two sub-assemblies in mutually stacked relation, thereby to form a resultant assembly. The components are typically provided by deposition on the electrodes and to protrude edgewise thereof beyond selected edges of the electrodes, thereby to form electrical contacts, and said locating of the sub-assemblies is carried out to cause said contacts to protrude in at least two different directions from the resultant assembly. The component typically consist of dielectric material, and the electrodes are typically deposited in the form of electrically conductive ink.

big_patent

RELATED APPLICATIONS [0001] This application claims benefit under 35 U.S.C. 119(e) from U.S. Provisional Application Ser. No. 61/038,227, filed on Mar. 20, 2008, entitled “Cellular Lattice Structures with Multiplicity of Cell Sizes and Related Method of Use,” the entire disclosure of which is hereby incorporated by reference in its entirety. US GOVERNMENT RIGHTS [0002] This invention was made with United States Government support under Grant No. N00014-07-1-0114, awarded by the Defense Advanced Research Projects Agency/Office of Naval Research. The United States Government has certain rights in the invention. FIELD OF INVENTION [0003] The present invention relates generally to cellular materials used in structural applications and specifically to materials comprising hierarchical cellular lattices and related methods of using and manufacturing the same. BACKGROUND OF THE INVENTION [0004] Sandwich panels are structural materials that may comprise a core enclosed between two sheets of material. Some of the existing lattice structure geometries used in sandwich panel cores include tetrahedral, pyramidal, and octet truss, kagome, and honeycomb. Typically, lattice structures utilizing trusses to form the core material of a sandwich panel are constructed from a lattice with a single unit cell size, that is, the trusses comprising the lattice are all of equal size. The size of the cells can of course be varied from one lattice to another, but typically in a given lattice, the cells are all of one size. SUMMARY OF THE INVENTION [0005] An embodiment of a sandwich panel core or the like that may be comprised of a lattice structure utilizing a network of hierarchical trusses, synergistically arranged, to provide support and other functionalities disclosed herein. Since this design results in a generally hollow core, the resulting structure maintains a low weight while providing high specific stiffness and strength. Sandwich panels are used in a variety of applications including sea, land, and air transportation, ballistics, blast and impact impulse mitigation, thermal transfer, multifunctional structures, armors, ballistics, load bearing, construction materials, and containers, to name a few. Any of the front, bottom or side panels involved may be an adjacent structure, component or system or may be integral with an adjacent structure, component or system. It should be appreciated that the panels (face sheets) may be applied to the sides, rather than only top and bottom. Adjacent structures may be, for example, floors, walls, substrates, platforms, frames, housings, casings, or infrastructure. Adjacent structures may be associated with, for example: land, air, water vehicles and crafts; weapons; armor; or electronic devices and housings. [0006] An aspect of an embodiment (or partial embodiment) comprises a structure. The structure may comprise a first lattice structure, the first lattice structure comprising: a first primary array, wherein the first primary array comprises an array of first order cells; and at least one of the first order cells comprising second order cells; an ancillary array, wherein the ancillary array comprises an array of second order cells; and at least one of the second order cells comprising third order cells; and wherein the ancillary array is nested with the first primary array, whereby the second order cells of the ancillary array are essentially coaligned with: the second order cells of the first primary array, the first order cells of the first primary array, or both the second order cells of the first primary array and the first order cells of the first primary array. An aspect of an embodiment (or partial embodiment) further comprises a second lattice structure, the second lattice structure comprising: a second primary array, wherein the second primary array comprises an array of first order cells; and wherein the second primary array is mated with the first primary array to form a third lattice structure, whereby at least one of the first order cells of the first primary array are oppositely oriented to and essentially coaligned with at least one of the first order cells of the second primary array. [0007] An aspect of an embodiment (or partial embodiment) comprises a structure. The structure may comprise a first lattice structure, the first lattice structure comprising: a first primary array, wherein the first primary array comprises an array of first order cells; and an ancillary array, wherein the ancillary array comprises an array of second order cells; and wherein the ancillary array is nested with the first primary array, whereby the second order cells of the ancillary array are essentially coaligned with the first order cells of the first primary array. An aspect of an embodiment (or partial embodiment) further comprises a second lattice structure, the second lattice structure comprising a second primary array, wherein the second primary array comprises an array of first order cells; and wherein the second primary array is mated with the first primary array to form a third lattice structure, whereby at least one of the first order cells of the first primary array are oppositely oriented to and essentially coaligned with at least one of the first order cells of the second primary array. [0008] An aspect of an embodiment (or partial embodiment) comprises a method of making a structure, the method comprising forming a first lattice structure through the steps comprising: providing a first primary array, wherein the first primary array comprises an array of first order cells; and at least one of the first order cells comprising second order cells; providing an ancillary array, wherein the ancillary array comprises an array of second order cells; and at least one of the second order cells comprising third order cells; and nesting the ancillary array with the first primary array, whereby the second order cells of the ancillary array are essentially coaligned with: the second order cells of the first primary array, the first order cells of the first primary array, or both the second order cells of the first primary array and the first order cells of the first primary array. An aspect of an embodiment (or partial embodiment) further comprises providing a second lattice structure, the method comprising: providing a second primary array, wherein the second primary array comprises an array of first order cells; and mating the second primary array with the first primary array to form a third lattice structure, whereby at least one of the first order cells of the first primary array are oppositely oriented to and essentially coaligned with at least one of the first order cells of the second primary array. [0009] An aspect of an embodiment (or partial embodiment) comprises a method of making a structure, the method comprising forming a first lattice structure through the steps comprising: providing a first primary array, wherein the first primary array comprises an array of first order cells; and providing an ancillary array, wherein the ancillary array comprises an array of second order cells; and nesting the ancillary array with the first primary array, whereby the second order cells of the ancillary array are essentially coaligned with the first order cells of the first primary array. An aspect of an embodiment (or partial embodiment) further comprises a providing a second lattice structure, the method comprising: providing a second primary array, wherein the second primary array comprises an array of first order cells; and mating the second primary array with the first primary array to form a third lattice structure, whereby at least one of the first order cells of the first primary array are oppositely oriented to and essentially coaligned with at least one of the first order cells of the second primary array. [0010] It should be appreciated that any number of arrays may be stacked, nested and mated on top of another. It should be appreciated that any number of the top, bottom, and side panels (facesheets) may be implemented by being attached or in communication with any of the arrays (and layers, stacking, mating and nesting of arrays). Further, it should be appreciated that any number of the top, bottom, and side panels (facesheets) may be implemented by being disposed between any of the arrays (and layers, stacking, mating and nesting of the arrays). [0011] These and other objects, along with advantages and features of the invention disclosed herein, will be made more apparent from the description, drawings and claims that follow. BRIEF DESCRIPTION OF THE DRAWINGS [0012] The foregoing and other objects, features and advantages of the present invention, as well as the invention itself, will be more fully understood from the following description of preferred embodiments, when read together with the accompanying drawings, in which: [0013] FIG. 1 schematically depicts a perspective view of unit cells of a lattice structure that may be used in constructing materials. [0014] FIG. 2 schematically depicts a perspective view of a primary array of unit cells and an ancillary array of unit cells. [0015] FIG. 3 schematically depicts an overhead plan view of a lattice structure wherein an ancillary array has been nested with a primary array. [0016] FIG. 4 schematically depicts a perspective view of a lattice structure and an oppositely oriented lattice structure ( FIG. 4A ) and wherein these two lattice structures can be mated to form mated lattice structure ( FIG. 4B ). [0017] FIG. 5 schematically depicts a side view of a balanced or mated lattice structure. [0018] FIG. 6 schematically depicts a side view of a balanced or mated lattice structure having face sheets (or panels) applied or disposed thereto. [0019] FIG. 7 schematically illustrates a perspective view of face sheets (or panels) being applied or disposed to a balanced or mated lattice structure. [0020] FIG. 8 schematically depicts an injection molding process for fabricating a unit cell of a cellular lattice by use of an injection molding apparatus and a mold. [0021] FIG. 9 schematically depicts a perspective view of a mold used to form an array of unit cells by an injection molding process. [0022] FIG. 10 schematically depicts a cell array being used as a template for the deposition of other materials; wherein the cell array is heated in a furnace without air, resulting in a carbonized unit cell array comprised of graphite; and wherein a deposition process results in a coated unit cell array. [0023] FIG. 11 schematically depicts a process for forming various developmental stages of a unit cell array. [0024] FIG. 12 schematically depicts a method of manufacture of an embodiment of tetrahedral unit cells of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION [0025] The present disclosure sets forth a hierarchical lattice structure that comprises unit cells of various sizes connected together to form a lightweight lattice structure with improved specific stiffness and strength. [0026] FIG. 1 schematically depicts unit cells of a lattice structure that may be used in constructing materials having exceptional stiffness and strength for a given mass or volume of material. FIG. 1A , for example, schematically depicts a perspective view of unit cell 100 that is a first order cell 101 comprised of three ligaments 102 . The hierarchical order of a structure is typically defined as the number of levels of scale that are present within a structure. A lattice framework made of trusses of equal size is considered to be of the first-order, a lattice framework having trusses of two different sizes would be considered to be of the second-order, and so on. Thus, in the present disclosure, the order of a cell corresponds to its size in relation to other cells, where size is measured by the length of a cell's ligaments. A first order cell has the longest ligament length of any cell used in a particular lattice structure, a second order cell has the second longest ligament length, and so on. For the purposes of this specification, larger cells will be referred to as being of a higher order than smaller cells. Thus a first order cell is of a higher order than a second order cell. Cells are considered to be of the same order if they are substantially similar in size. Although ligament length is variable, an exemplary embodiment may include a unit cell 100 wherein the length of each ligament is within the range of about fifty micrometers to tens of meters. Ligaments 102 may be of any desirable cross section, including but not limited to circular or rectangular. [0027] It should be appreciated that the cross sectional shapes of the ligaments may also be varied in order to change the overall structural properties of the lattice structure, as well as for other desired or required purposes. Possible cross sectional shapes for the ligaments include, but are not limited thereto the following: circular, triangular, rectangular, square, oval and hexagonal (or any combination or variation as desired or required). [0028] It should be appreciated that the ligaments may be hollow, semi-solid, or solid, or any combination thereof. [0029] In FIG. 1A , unit cell 100 is depicted by way of example and not limitation as having a tetrahedral geometric structure. In other embodiments, the geometric structure of unit cell 100 may be, but is not limited to, pyramidal, octet truss, or three-dimensional Kagome. It should be appreciated that other embodiments may include any unit cell that may be nested and mated according to the teachings of the present disclosure. Unit cells may also be comprised of multiple cell sizes. For example, as shown in FIG. 1B , unit cell 110 is comprised of a first order cell 101 formed by ligaments 102 , and three second order cells 103 each formed by two of ligaments 104 and a portion of a ligament 102 . As another example, as shown in FIG. 1C , unit cell 120 is comprised of a second order cell 103 formed by ligaments 122 , and three third order cells 105 each formed by two of ligaments 124 and a portion of a ligament 122 . Unit cells can be comprised of more than two orders of cells. For example, unit cell 110 could also be comprised of one or more third order cells that each utilize a portion of a ligament 102 of the first order cells or a portion of a ligament 104 of the second order cells, along with two additional ligaments, where the two additional ligaments are smaller than ligaments 104 of the second order cells. In other embodiments, the unit cell 110 may be comprised of less than three second order cells, including zero second order cells. Similarly, unit cell 120 could be comprised of less than three third order cells. Other unit cells may be comprised of cells of an order lower than two, for example a unit cell may be comprised of a third order cell and three or less fourth order cells. [0030] Unit cells of other embodiments of the present disclosure may comprise more or less than three second order cells. For example, if unit cell 100 included a fourth ligament such that the shape of the unit cell was pyramidal, such a unit cell could also be comprised of four second order pyramidal cells, where each second order cell would utilize a portion of a ligament of the first order cell as one of its ligaments. [0031] Although FIG. 1 shows the second order cells formed by ligaments 104 and portions of ligaments 102 as tetrahedral in shape, in other embodiments these second order cells may be, but are not limited to, pyramidal, octet truss, or three-dimensional Kagome in shape, or any combination thereof. Similarly, any cells of an order lower than two, such as the third order tetrahedral cells 105 formed by ligaments 124 and portions of ligaments 122 , may also be of shapes other than tetrahedral. Furthermore, the lower order cells need not be geometrically similar to higher order cells such as first order cell 100 . As an example, the angles between the ligaments comprising the second order cells may differ from the angles between the ligaments comprising the first order cells. The ligaments of lower order cells may, but are not required to, connect with the ligaments of an adjacent lower order cell. As an example of ligaments of adjacent cells connected together, in FIG. 1B , a ligament 104 of a second order cell 103 is connected at node 106 to a ligament of an adjacent second order cell. [0032] The materials for manufacturing these unit cells encompass any material subject to deformation, punch and die, casting, injection molding, or other forming methods: these include, but are not limited to, metals, metal alloys, inorganic polymers, organic polymers, ceramics, glasses, and all composite derivatives, or any combination thereof. In some embodiments, the material used to construct cells of one order may be different than the material used to construct cells of another order. In some embodiments, different cells of the same order may be comprised of different materials. Similarly, as will be discussed later, panels implemented with the core may be of the same or different materials as the core. [0033] FIG. 2 schematically depicts a primary array 130 of unit cells 110 replicated in two dimensions. As shown in FIG. 2A , the primary array may be formed by joining ligaments of adjacent cells together at nodes. In some embodiments, multiple cells of the primary array 130 may be constructed concurrently, such that the ligaments of adjacent cells are joined during the fabrication process. In other embodiments, cells of the primary array may be attached through their ligaments by other suitable means, including but not limited to brazing, transient liquid phase bonding, welding, diffusion bonding, or adhesive bonding after construction (or any other available adhesion process). In some embodiments, if the cells are constructed of a polymer they are attached together by an adhesive. In some embodiments, if the cells are constructed of a metal, they are attached through welding or brazing. Similarly, multiple primary arrays 130 can be attached to each other by suitable means after construction by attaching ligaments of their respective cells. In other embodiments, the cells of the primary array need not be joined together, so long as they are in close proximity with each other. FIG. 2A also depicts an ancillary array 140 of unit cells 120 replicated in two dimensions. As shown, these unit cells 120 are not required to be connected through their respective ligaments, though in some embodiments these adjacent ligaments may indeed be connected. Ancillary array 140 may be nested with primary array 130 to form lattice structure 200 . [0034] Nesting may be accomplished when a portion of a ligament of a higher order cell of a primary array abuts a ligament of a lower order cell of an ancillary array along at least a substantial portion of the length of the ligament of the lower order cell. Nesting may also occur when a ligament of a cell from an ancillary array abuts along at least a substantial portion of the length of a ligament of a similarly ordered cell of a primary array. When either or both of these nesting scenarios occur, the respective cells are said to be nested and “co-aligned” with each other. When at least one cell from a primary array is nested with at least one cell from an ancillary array, the arrays are said to be nested with each other. In an embodiment, when two arrays are nested, at least one ligament of each of the highest ordered cells in the ancillary array will abut to a portion of a ligament of one of the highest ordered cells in the primary array. As an example, in referring to FIG. 2B , after nesting, one ligament of each of the second order cells 103 of unit cell 120 abuts with a portion of a ligament of a first order cell 101 of unit cell 110 . In some embodiments and as shown in FIG. 2B , nesting may also occur because other ligaments of the second order cells 103 of unit cell 120 abut with the ligaments of the second order cells 103 of unit cell 110 . In other embodiments, there may be further nesting between lower order cells. For example, an array of third order cells could be nested with the ancillary array 140 , and an array of fourth order cells could be nested with the array of third order cells, and so on. Nesting can also occur between cells that have a difference of order greater than one. For example, an array of third order cells could nest with an array of first order cells. This nesting of lower order cells with higher order cells as described herein results in a lattice with a hierarchical structure. [0035] FIG. 3 schematically depicts an overhead plan view of a lattice structure 200 wherein an ancillary array 140 has been nested with a primary array 130 . Ligaments 102 form the first order cells, ligaments 104 along with portions of ligaments 102 form the second order cells, and ligaments 124 along with portions of ligaments 104 form the third order cells. Because in the lattice structure comprising nested arrays in FIG. 3 , ligaments 122 abut substantially with ligaments 104 , only ligaments 104 are explicitly shown. In FIG. 3 , each cell is of a tetrahedral shape. [0036] FIG. 4 schematically depicts a perspective view of a lattice structure 200 and an oppositely oriented lattice structure 210 ( FIG. 4A ). These two lattice structures can be mated to form mated lattice structure 220 ( FIG. 4B ). Mating is accomplished when at least one ligament of at least one of the highest order cells of an array or lattice structure abuts with at least a substantial portion of at least one ligament of at least one of the highest order cells of an oppositely oriented lattice structure or array. In some embodiments of a mated lattice structure or array, substantially all of the ligaments of the highest order cells of a lattice structure or array abut with at least a substantial portion of one of the ligaments of the highest order cells of an oppositely oriented lattice structure. This is shown by way of example in FIG. 4B where the ligaments of the highest order cells of lattice structure 200 abut with the ligaments of the highest order cells of oppositely oriented lattice structure 210 . When the ligaments abut along at least a substantial portion of their respective lengths, the corresponding cells are said to be “co-aligned” with each other. In FIG. 4 , it is readily observable that, excepting the cells at the boundary, each ligament of the highest order cells of oppositely oriented lattice structure 210 abuts along at least a substantial portion of its length with a ligament of the highest order cells of lattice structure 200 , such that the cells of these respective lattice structures are co-aligned with each other. Mated lattice structures may also be referred to as balanced lattice structures. [0037] In FIG. 4 , the lattice structure 200 and the oppositely oriented lattice structure 210 are each shown by way of example and not limitation as comprised of a primary array 130 and an ancillary array 140 , with each array having two orders of cells. In reality, all that is necessary for mating are two lattice structures each comprised of a primary array of first order cells. In other embodiments, one or both of the mated lattice structures may also be comprised of multiple orders of cells. [0038] FIG. 5 and FIG. 6 schematically depict a side view of balanced or mated lattice structure 220 . FIG. 6 also schematically illustrates face sheets 230 (or panels) being applied to a balanced or mated lattice structure 220 . FIG. 7 schematically illustrates a perspective view of face sheets being applied to a balanced lattice structure 220 . In some embodiments, after mating, a solid face sheet 230 may be attached either directly or indirectly, to the top, the bottom, or both the top and bottom of the balanced lattice structure 220 . In other embodiments, a solid face sheet 230 may be attached either directly or indirectly, to the top, the bottom, or both the top and bottom of a lattice structure 200 or a primary array 130 . The face sheets 230 may be attached by any suitable means, including but not limited to brazing, transient liquid phase bonding, welding, diffusion bonding, or adhesive bonding. Alternatively, an open cell face sheet may be used in place of solid face sheet 230 in any of these configurations [0039] By way of example and not limitation, the lattice structures provided herein are illustrated as comprising unit cells replicated in two dimensions. In other embodiments, although not shown, the unit cells making up a lattice structure may also be formed in three dimensions, thus creating a three dimensional cube-shaped array or lattice structure. In other embodiments, the unit cells making up a lattice structure could be replicated solely in one dimension. [0040] It should be appreciated that any one of the primary arrays, nested arrays, or mated arrays or lattice structures, or combinations thereof may be implemented as the core of a sandwich panel or other structure that the core or panel may be in communication with. The panels and/or cores may be implemented with or as part of floors, columns, beams, walls, jet or rocket nozzles, land, air or water vehicles/ships, armor, etc. [0041] It should be appreciated that any face sheets (or any desired or required components or structures) may be attached to the core (or in communication with the core or other structure or components) by any suitable means, including but not limited to brazing, transient liquid phase bonding, welding, diffusion bonding, or adhesive bonding after construction (or any other available adhesion process). In some embodiments, if the materials are constructed of a polymer they are attached together by an adhesive. In some embodiments, if the materials are constructed of a metal, they are attached through welding or brazing. [0042] By way of example and not limitation, the lattice structures and arrays shown in the figures of the present disclosure as resting on a flat surface. In some embodiments a lattice structure or array may be curved, such that it does not rest on a flat surface. For example, a lattice structure might take the shape of an arc or be used to form the shell of a cylinder. Thus, since in some embodiments the lattice structure may be curved, any face sheet applied to such an embodiment will also be curved. In some embodiments, the lattice structure might be used to form a rocket or jet fuel nozzle. For example, the core or lattice (with or without panels) may be circular or at least semi-circular to provide an opening or nozzle for a jet or rocket. Similar designs may be implemented to provide a conduit or structure for any medium transfer there through. This application of the lattice structure is facilitated by the structure's high strength and thermal conductivity. [0043] The core or lattice (with or without panels) may be implemented for walls or floors for housings, compartments, buildings, floors, vehicles, or infrastructure. [0044] The lattice structures described above have many applications including use as the cores of sandwich panel structures. Utilizing embodiments of the present disclosure, sandwich panels with ultra-light and high specific stiffness and strength lattice cores can be designed to outperform competing load supporting structures made with honeycomb or other conventional cores. These sandwich panels may be used in minimum weight structural applications, including many forms of mechanized transportation. Embodiments of the present disclosure can also be used to construct materials with improved impact or blast load mitigation. For example, these materials can sustain larger compressive forces along their struts before truss buckling occurs and they can suffer larger face sheet deformations before face sheet tearing is initiated. Embodiments of the present disclosure also enable materials with superior cross flow heat exchange, since the hollow structure allows coupling of a fluid coolant driven between the struts to heat transported through the struts by conduction. The hollow structure also enables the placement of other elements within the core. Embodiments of the present disclosure may also be used to create armors that have high ballistic resistance, in other words the strength of the structure increases the force needed to crush the material. Embodiments of the present disclosure may also be used to create armors, storage or buildings that mitigate blast impact. [0045] An embodiment of this present disclosure can be designed to control the collapse of the first order cells during an impact with a rigid object, making it a preferred material system for impact or blast energy absorption. The increased surface area of a structure with a multiplicity of cell sizes can also be used as a support system for catalysts where the large cell size regions provide easy transport of reactants and products of the reaction enhanced at the catalytically coated surfaces of the trusses. When cells are arranged in this way, a high surface energy is enabled upon which other materials can be added for a wide range of applications. For example, an embodiment of the present disclosure could be used for the deposition of thin film batteries resulting in a load supporting, easily cooled structure with a very high energy storage density. [0046] In some embodiments of the present disclosure, arrays of unit cells (unit cell arrays) can be fabricated from thermoformable materials through the use of an injection molding process. FIG. 8 schematically depicts an injection molding process for fabricating a unit cell of a cellular lattice by use of an injection molding apparatus 500 and a mold 510 . In an embodiment, a granular thermoplastic polymer 502 is fed into a cylinder 504 , where the polymer is heated by heater 506 into a liquid form before being propelled through nozzle 508 into a mold 510 by rotating screw 512 . The injection apparatus 500 is then separated from the mold 510 and the liquid polymer is allowed to cool and harden. After cooling, the respective parts of the mold 510 are separated and unwanted portions of the cooled polymer may be cropped ( FIG. 8B ). This process results in the formation of a unit cell 514 . [0047] In certain embodiments, the polymer 502 may be polypropylene, but alternative embodiments may use any other suitable thermoplastic polymer capable of being heated into a liquid state and then cooled to a solid state. By way of example and not limitation, polystyrene and polyethylene could also be used. One skilled in the art will recognize that in other embodiments, many different methods for injecting liquid into a mold could be used. Other embodiments may use any suitable injection apparatus to propel two or more polymers into a mold to form a unit cell in a process known as reaction injection molding. Still other embodiments may use any suitable injection apparatus to propel liquid metal into a mold to form a unit cell in a process known as metal injection molding. Still other embodiments may use any suitable injection apparatus to inject ceramic materials mixed with thermoplastic binders into a mold to form a unit cell in a process known as ceramic injection molding. [0048] FIG. 9 schematically depicts a perspective view of a mold 600 used to form an array of unit cells 602 by an injection molding process. [0049] A cell array 602 formed by an injection molding process may be used in various applications to provide support in structural materials. A cell array 602 formed by an injection molding process may also be used as a template in further processing, as shown in FIG. 10 and FIG. 11 . [0050] FIG. 10 schematically depicts a cell array 602 being used as a template for the deposition of other materials. In some embodiments, after formation through injection molding using polymers, the cell array 602 is heated in a furnace without air, resulting in a carbonized unit cell array 702 comprised of graphite, or other suitable material as desired or required. This carbonized cell array 702 has a higher melting temperature than a normal cell array 602 . The carbonized unit cell array is then placed in a heated chamber 700 . Various gases are supplied to the chamber and interact with each other to form solids. This process results in a solid coating over the carbonized unit cell array 702 . Waste gases flow out of the chamber through an outlet. As an example, and not by way of limitation, FIG. 10 depicts the deposition of silicon carbide (SiC) on the carbonized unit cell array 702 . This is accomplished by placing the carbonized unit cell array 702 in the heated chamber 700 and feeding argon 704 , hydrogen 706 , and methyltrichlorosilane (CH 3 SiCl 3 ) 708 into the chamber 700 . The gases will react, leaving a coating of SiC on the carbonized unit cell array 702 . The waste gases of hydrogen, argon, and hydrogen chloride flow through an outlet of the chamber 700 . Other embodiments may substitute any gases capable of interacting with each other to form a deposition on the carbonized unit cell array 702 . Deposition may occur by any suitable means capable of permitting vapor transport to all surfaces of the carbonized unit cell array 702 , including but not limited to, chemical vapor deposition, and directed vapor deposition. [0051] If a hollow truss structure is desired, the inner material of the coated carbonized unit cell array 702 can be removed by the process of burnout, by which the coated carbonized unit cell array 702 is subjected to a temperature that exceeds the melting point of the inner material of the coated carbonized unit cell array 702 but not the deposited material, thus leaving the deposited material in tact in the same shape as the original unit cell array 602 . While the preceding example involves a carbonized polymeric unit cell array used as a template for deposition, other embodiments may utilize unit cell arrays made from other types of materials, including but not limited to metals, metal alloys, inorganic polymers, organic polymers, ceramics, glasses, and all composite derivatives, or any combination thereof. [0052] FIG. 1 schematically depicts a polymeric unit cell array 602 being used as a template for investment casting of a unit cell array. In an embodiment, the process begins with a unit cell array 602 with uncropped risers 802 made from a polymer material 804 ( FIG. 11A ). The unit cell array 602 is then immersed in liquid casting slurry 806 or other suitable material or process ( FIG. 11B ). After the casting slurry dries, the unit cell array 602 is composed of the polymer material 804 and the slurry coating 808 . The unit cell array 602 is then placed in furnace 810 and the polymer material core 804 is burned out, leaving a hollow negative template comprised of the slurry coating 808 ( FIG. 11C ). Molten metal 811 or other suitable liquid material is then poured into this template ( FIG. 11D ). After cooling, the unit cell array 602 is comprised of a solid metal core 812 and a slurry coating 808 . This slurry coating 808 is then removed ( FIG. 11E ), leaving a unit cell array comprised of solid metal 812 . The solid metal unit cell array can then be tested for structural soundness. By way of example and not limitation, the electrical resistivity of the solid metal unit cell array in FIG. 11F may be measured with an ohmmeter or by applying a current to the unit cell array and measuring a voltage drop across the unit cell array with a voltmeter. [0053] FIG. 12 depicts a method of manufacture of an embodiment of tetrahedral unit cells of the present disclosure. Referring to FIG. 12A , individual hexagons 160 with tabs 162 extending in both directions from every other vertex may be die cast, stamped from sheet goods, or cut from an extruded profile. Each piece is then deformed with a die 156 and punch 154 tool assembly to form unit cell 110 . Similarly, referring to FIG. 12B , individual hexagons 170 with tabs 172 extending in both directions from every other vertex may also be die cast, stamped from sheet goods, or cut from an extruded profile and then deformed with a die 152 and punch 150 tool assembly to form unit cell 120 . Unit cell 120 may be nested with unit cell 110 . After nesting, these unit cells may be held in place via a resistance weld, or other suitable means at the lower portion of each major ligament. Collections of these individual units may be subsequently joined in rows and placed in a packed array between face sheets that may (or may not) have channels or indentations to provide for correct alignment. The assembly is subjected to a joining process such as, but not limited, to brazing, transient liquid phase bonding, welding, diffusion bonding, or adhesive bonding depending on the materials used. The result is a sandwich panel that contains a hierarchical truss core network and exhibits significant improvements in strength. [0054] A person skilled in the art would recognize that the lattice structures described in the present disclosure could be manufactured in other ways including lattice block construction, constructed metal lattice, and metal textile lay-up techniques. [0055] It should be appreciated that various aspects of embodiments of the present method, system, devices, article of manufacture, and compositions may be implemented with the following methods, systems, devices, article of manufacture, and compositions disclosed in the following U.S. patent applications, U.S. patents, and PCT International patent applications and are hereby incorporated by reference herein and co-owned with the assignee: [0056] International Application No. PCT/US2009/034690 entitled “Method for Manufacture of Cellular Structure and Resulting Cellular Structure,” filed Feb. 20, 2009. [0057] International Application No. PCT/US2008/073377 entitled “Synergistically-Layered Armor Systems and Methods for Producing Layers Thereof,” filed Aug. 15, 2008. [0058] International Application No. PCT/US2008/060637 entitled “Heat-Managing Composite Structures,” filed Apr. 17, 2008. [0059] International Application No. PCT/US2007/022733 entitled “Manufacture of Lattice Truss Structures from Monolithic Materials,” filed Oct. 26, 2007. [0060] International Application No. PCT/US2007/012268 entitled “Method and Apparatus for Jet Blast Deflection,” filed May 23, 2007. [0061] International Application No. PCT/US04/04608, entitled “Methods for Manufacture of Multilayered Multifunctional Truss Structures and Related Structures There from,” filed Feb. 17, 2004, and corresponding U.S. application Ser. No. 10/545,042, entitled “Methods for Manufacture of Multilayered Multifunctional Truss Structures and Related Structures There from,” filed Aug. 11, 2005. [0062] International Application No. PCT/US03/27606, entitled “Method for Manufacture of Truss Core Sandwich Structures and Related Structures Thereof,” filed Sep. 3, 2003, and corresponding U.S. application Ser. No. 10/526,296, entitled “Method for Manufacture of Truss Core Sandwich Structures and Related Structures Thereof,” filed Mar. 1, 2005. [0063] International Patent Application Serial No. PCT/US03/27605, entitled “Blast and Ballistic Protection Systems and Methods of Making Same,” filed Sep. 3, 2003. [0064] International Patent Application Serial No. PCT/US03/23043, entitled “Method for Manufacture of Cellular Materials and Structures for Blast and Impact Mitigation and Resulting Structure,” filed Jul. 23, 2003. [0065] International Application No. PCT/US03/16844, entitled “Method for Manufacture of Periodic Cellular Structure and Resulting Periodic Cellular Structure,” filed May 29, 2003, and corresponding U.S. application Ser. No. 10/515,572, entitled “Method for Manufacture of Periodic Cellular Structure and Resulting Periodic Cellular Structure,” filed Nov. 23, 2004. [0066] International Application No. PCT/US02/17942, entitled “Multifunctional Periodic Cellular Solids and the Method of Making Thereof,” filed Jun. 6, 2002, and corresponding U.S. application Ser. No. 10/479,833, entitled “Multifunctional Periodic Cellular Solids and the Method of Making Thereof,” filed Dec. 5, 2003. [0067] International Application No. PCT/US01/25158 entitled “Multifunctional Battery and Method of Making the Same,” filed Aug. 10, 2001, U.S. Pat. No. 7,211,348 issued May 1, 2007 and corresponding U.S. application Ser. No. 11/788,958, entitled “Multifunctional Battery and Method of Making the Same,” filed Apr. 23, 2007. [0068] International Application No. PCT/US01/22266, entitled “Method and Apparatus For Heat Exchange Using Hollow Foams and Interconnected Networks and Method of Making the Same,” filed Jul. 16, 2001, U.S. Pat. No. 7,401,643 issued Jul. 22, 2008 entitled “Heat Exchange Foam,” and corresponding U.S. application Ser. No. 11/928,161, “Method and Apparatus For Heat Exchange Using Hollow Foams and Interconnected Networks and Method of Making the Same,” filed Oct. 30, 2007. [0069] International Application No. PCT/US01/17363, entitled “Multifunctional Periodic Cellular Solids and the Method of Making Thereof,” filed May 29, 2001, and corresponding U.S. application Ser. No. 10/296,728, entitled “Multifunctional Periodic Cellular Solids and the Method of Making Thereof,” filed Nov. 25, 2002. [0070] It should be appreciated that various aspects of embodiments of the present method, system, devices, article of manufacture, and compositions may be implemented with the following methods, systems, devices, article of manufacture, and compositions disclosed in the following U.S. patent applications, U.S. patents, and PCT International patent applications, and scientific articles, and are hereby incorporated by reference herein: 1. Lakes, R., “Materials with Structural Hierarchy”, Nature, Vol. 361, Feb. 11, 1993, Pages 511-515. 2. U.S. Patent Application Publication No. 2005/0126106 A1, Murphy, et al., “Deployable Truss Having Second Order Augmentation”, Jun. 16, 2005. 3. U.S. Patent Application Publication No. 2007/0256379 A1, Edwards, C., “Composite Panels”, Nov. 8, 2007. 4. U.S. Pat. No. 4,722,162, Wilensky, J., “Orthogonal Structures Composed of Multiple Regular Tetrahedral Lattice Cells”, Feb. 2, 1988. 5. U.S. Pat. No. 6,644,535 B2, Wallach, et al., “Truss Core Sandwich Panels and Methods for Making Same”, Nov. 11, 2003. 6. U.S. Pat. No. 6,931,812 B1, Lipscomb, “Wet Structure and Method for Making the Same”, Aug. 23, 2005. [0077] Of course it should be understood that a wide range of changes and modifications could be made to the preferred and alternate embodiments described above. It is therefore intended that the foregoing detailed description be understood that it is the following claims, including all equivalents, which are intended to define the scope of this invention. [0078] In summary, while the present invention has been described with respect to specific embodiments, many modifications, variations, alterations, substitutions, and equivalents will be apparent to those skilled in the art. The present invention is not to be limited in scope by the specific embodiment described herein. Indeed, various modifications of the present invention, in addition to those described herein, will be apparent to those of skill in the art from the foregoing description and accompanying drawings. Accordingly, the invention is to be considered as limited only by the spirit and scope of the following claims, including all modifications and equivalents. [0079] Still other embodiments will become readily apparent to those skilled in this art from reading the above-recited detailed description and drawings of certain exemplary embodiments. It should be understood that numerous variations, modifications, and additional embodiments are possible, and accordingly, all such variations, modifications, and embodiments are to be regarded as being within the spirit and scope of this application. For example, regardless of the content of any portion (e.g., title, field, background, summary, abstract, drawing figure, etc.) of this application, unless clearly specified to the contrary, there is no requirement for the inclusion in any claim herein or of any application claiming priority hereto of any particular described or illustrated activity or element, any particular sequence of such activities, or any particular interrelationship of such elements. Moreover, any activity can be repeated, any activity can be performed by multiple entities, and/or any element can be duplicated. Further, any activity or element can be excluded, the sequence of activities can vary, and/or the interrelationship of elements can vary. Unless clearly specified to the contrary, there is no requirement for any particular described or illustrated activity or element, any particular sequence or such activities, any particular size, speed, material, dimension or frequency, or any particularly interrelationship of such elements. Accordingly, the descriptions and drawings are to be regarded as illustrative in nature, and not as restrictive. Moreover, when any number or range is described herein, unless clearly stated otherwise, that number or range is approximate. When any range is described herein, unless clearly stated otherwise, that range includes all values therein and all sub ranges therein. Any information in any material (e.g., a United States/foreign patent, United States/foreign patent application, book, article, etc.) that has been incorporated by reference herein, is only incorporated by reference to the extent that no conflict exists between such information and the other statements and drawings set forth herein. In the event of such conflict, including a conflict that would render invalid any claim herein or seeking priority hereto, then any such conflicting information in such incorporated by reference material is specifically not incorporated by reference herein.

A sandwich panel core that may be comprised of a lattice structure utilizing a network of hierarchical trusses, synergistically arranged, to provide support and other functionalities disclosed herein. Since this design results in a generally hollow core, the resulting structure maintains a low weight while providing high specific stiffness and strength. Sandwich panels are used in a variety of applications including sea, land, and air transportation, ballistics, blast impulse mitigation, impact mitigation, thermal transfer, ballistics, load bearing, multifunctional structures, armors, construction materials, and containers, to name a few.

big_patent

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a national stage application under 35 U.S.C. 371 of PCT Application No. PCT/IB2008/050456 having an international filing date of 8 Feb. 2008, which designated the United States, which PCT application claimed the benefit of U.S. Application No. 60/900,935 filed 12 Feb. 2007 and U.S. Application No. 60/901,251 filed 14 Feb. 2007, the entire disclosures of which are incorporated herein by reference. FIELD This invention relates to the co-production of power and hydrocarbons. In particular, the invention relates to a process for co-producing power and hydrocarbons. BACKGROUND Coal is used as a feedstock for production of power and for production of hydrocarbons. It is generally accepted that Integrated Gasification Combined Cycle (IGCC) processes have environmental advantages over conventional coal-fired power plants. In IGCC processes coal is first gasified to produce synthesis gas and the synthesis gas then serves as fuel source to a combined cycle power production stage. One route for production of hydrocarbons from coal is to gasify coal to produce synthesis gas and then to convert the synthesis gas to hydrocarbons. It would be an advantage to provide an IGCC process integrated with a hydrocarbon production process which shows economic (i.e. capital and operating cost) benefits and environmental benefits. SUMMARY As used in this specification, the term wet gasification stage means an entrained flow gasification stage in which water is used as a carrier for solid feedstock (e.g. coal). It is thus a slurry that is fed to the gasification stage. As used in this specification, the term dry gasification stage means an entrained flow gasification stage in which a gas is used as a carrier for solid feedstock (e.g. coal). According to the invention, there is provided a process for co-producing power and hydrocarbons, the process including in a wet gasification stage, gasifying coal to produce a combustion gas at elevated pressure comprising at least H 2 and CO; enriching a first portion of the combustion gas with H 2 to produce an H 2 -enriched gas; generating power from a second portion of the combustion gas; in a dry gasification stage, gasifying coal to produce a synthesis gas precursor at elevated pressure comprising at least H 2 and CO; mixing at least a portion of the H 2 -enriched gas with the synthesis gas precursor to provide a synthesis gas for hydrocarbon synthesis; and synthesising hydrocarbons from the synthesis gas. The combustion gas may be produced at a pressure of at least 45 bar, more preferably at least 55 bar, most preferably at least 65 bar, e.g. about 70 bar. Typically, the wet gasification stage uses a water quench to cool the combustion gas. The molar ratio of H 2 and CO in the combustion gas may be higher than the molar ratio of H 2 and CO in the synthesis gas precursor. For avoidance of doubt, the phrase “the molar ratio of H 2 and CO” as used in this specification means the molar concentration of H 2 divided by the molar concentration of CO. The molar ratio of H 2 /CO has an identical meaning. The molar ratio of H 2 /CO in the combustion gas may be at least 0.6. Preferably, the molar ratio is at least 0.8, more preferably at least 0.9, e.g. about 0.96. Typically, the molar ratio of H 2 /CO in the combustion gas is between 0.6 and 1.0. The dry gasification stage should produce synthesis gas at a pressure which is sufficiently high, taking into account pressure losses over process units to allow hydrocarbon synthesis at a suitably high pressure. Typically the synthesis gas precursor is at a pressure of between about 40 bar and about 50 bar, e.g. about 45 bar. Typically, the dry gasification stage includes a gasification stage waste heat boiler. The molar ratio of H 2 /CO in the synthesis gas precursor may be between about 0.3 and about 0.6, typically between about 0.3 and about 0.4, e.g. about 0.4. Enriching a first portion of the combustion gas with H 2 may include subjecting said first portion to water gas shift conversion thereby to produce the H 2 -enriched gas. Typically the water gas shift conversion is a sour shift, i.e. containing a catalyst suitable for reacting carbon monoxide and water to produce additional hydrogen in the presence of sulphur. The process may include purifying a portion of the H 2 -enriched gas, e.g. by using membranes and/or pressure swing adsorption, to produce essentially pure hydrogen. The essentially pure hydrogen may be used for hydroprocessing of hydrocarbons synthesised from the synthesis gas. The H 2 -enriched gas may be at elevated pressure. Mixing at least a portion of the H 2 -enriched gas with the synthesis gas precursor may include passing the H 2 -enriched gas through an expansion turbine to generate power. Generating power from a second portion of the combustion gas may include combusting the combustion gas at elevated pressure in the presence of oxygen to produce hot combusted gas and expanding the hot combusted gas through a gas turbine expander to generate power and to produce hot exhaust gas. Typically, the combustion of the combustion gas occurs in a combustor. The hot exhaust gas may be at or above atmospheric pressure. Generating power from a second portion of the combustion gas may also include recovering heat from the hot exhaust gas in a waste heat recovery stage. Typically, the waste heat recovery stage includes a waste heat recovery stage waste heat boiler. Typically, recovering heat from the hot exhaust gas in the waste heat recovery stage thus includes generating steam in the waste heat recovery stage waste heat boiler. The generated steam may be used to drive a steam turbine to produce power or the steam may be used elsewhere in the process for other purposes. The waste heat recovery stage waste heat boiler may be a co-fired waste heat boiler. The synthesising of hydrocarbons from the synthesis gas may produce a fuel gas. The waste heat recovery stage waste heat boiler may be co-fired with the fuel gas to raise the pressure and/or the temperature of the steam generated by the waste heat recovery stage waste heat boiler. The process may include separating air to produce oxygen. The oxygen may be used to combust the combustion gas to produce the hot combustion gas. Typically, the oxygen must be produced at pressure to exceed the operating pressure of a combustor in which the combustion gas is combusted. Typically liquid oxygen is pumped to the required pressure and the liquid oxygen is then heated to produce oxygen gas which is then used to combust the combustion gas. The oxygen, at lower pressure, may also be used to combust the fuel gas thereby to co-fire the waste heat recovery stage waste heat boiler. The oxygen is typically also used in the wet gasification stage and in the dry gasification stage to gasify coal. This oxygen is the highest pressure oxygen used and the required pressure is typically achieved by pumping liquid oxygen, which is then evaporated at pressure. Synthesising hydrocarbons from the synthesis gas may be effected in any conventional fashion. Typically, the synthesising of hydrocarbons from the synthesis gas includes Fischer-Tropsch synthesis using one or more Fischer-Tropsch hydrocarbon synthesis stages, producing one or more hydrocarbon product streams and a Fischer-Tropsch tail gas which includes CO 2 , CO and H 2 . The one or more Fischer-Tropsch hydrocarbon synthesis stages may be provided with any suitable reactors such as one or more reactors selected from fixed bed reactors, slurry bed reactors, ebullating bed reactors or dry powder fluidised bed reactors. The pressure in the reactors may be between 1 bar and 100 bar, typically below 45 bar, while the temperature may be between 160° C. and 380° C. One or more of the Fischer-Tropsch hydrocarbon synthesis stages may be a low temperature Fischer-Tropsch hydrocarbon synthesis stage operating at a temperature of less than 280° C. Typically, in such a low temperature Fischer-Tropsch hydrocarbon synthesis stage, the hydrocarbon synthesis stage operates at a temperature of between 160° C. and 280° C., preferably between 220° C. and 260° C., e.g. about 250° C. Such a low temperature Fischer-Tropsch hydrocarbon synthesis stage is thus a high chain growth, typically slurry bed, reaction stage, operating at a predetermined operating pressure in the range of 10 to 50 bar, typically below 45 bar. One or more of the Fischer-Tropsch hydrocarbon synthesis stages may be a high temperature Fischer-Tropsch hydrocarbon synthesis stage operating at a temperature of at least 320° C. Typically, such a high temperature Fischer-Tropsch hydrocarbon synthesis stage operates at a temperature of between 320° C. and 380° C., e.g. about 350° C., and at an operating pressure in the range of 10 to 50 bar, typically below 45 bar. Such a high temperature Fischer-Tropsch hydrocarbon synthesis stage is a low chain growth reaction stage, which typically employs a two-phase fluidised bed reactor. In contrast to the low temperature Fischer-Tropsch hydrocarbon synthesis stage, which may be characterised by its ability to maintain a continuous liquid product phase in a slurry bed reactor, the high temperature Fischer-Tropsch hydrocarbon synthesis stage cannot produce a continuous liquid product phase in a fluidised bed reactor. The Fischer-Tropsch tail gas may be treated to remove CO 2 . The CO 2 may be removed in any conventional fashion, e.g. by using a Benfield solution. Typically, the Fischer-Tropsch tail gas is subjected to a water gas shift stage to convert CO to CO 2 and to produce more H 2 . The water gas shift stage would typically be a conventional water gas shift stage, i.e. a sweet shift stage. The process may include separating H 2 from the Fischer-Tropsch tail gas (e.g. using pressure swing adsorption) and recycling the H 2 to the one or more Fischer-Tropsch hydrocarbon synthesis stages. The process may include treating the synthesis gas precursor or the synthesis gas to remove sulphur and/or CO 2 . Treating the synthesis gas precursor or the synthesis gas may be effected in any conventional fashion, e.g. using a Rectisol process which includes a chilled methanol wash. The process may include feeding a portion of the CO 2 obtained from the treatment of synthesis gas precursor or synthesis gas and/or from the treatment of the Fischer-Tropsch tail gas to a combustor used to generate power from the second portion of the combustion gas to act as a temperature moderating agent. Typically, this will include compressing the CO 2 to exceed the operating pressure of the combustor. The compressed CO 2 may be mixed with oxygen already at pressure, before being fed to the combustor. The process may include treating exhaust gas from the waste heat recovery stage waste heat boiler, comprising predominantly CO 2 and water, to remove the water, leaving a CO 2 exhaust stream which may be sequestrated in any conventional fashion, or captured for further use. The CO 2 exhaust stream may be combined with a further portion of CO 2 obtained from the treatment of synthesis gas precursor or synthesis gas and/or from the treatment of the Fischer-Tropsch tail gas. Instead or in addition, the process may include recycling some of the exhaust gas from the waste heat recovery stage waste heat boiler, or some of the CO 2 exhaust stream, to the combustor. The process may include superheating steam from the waste heat recovery stage waste heat boiler using the fuel gas and air. In this event, a stack gas produced by the superheating of the steam should not be mixed with exhaust gas from the waste heat recovery stage waste heat boiler or with the hot exhaust gas from the gas turbine expander. The process may include using, instead of air, essentially pure oxygen or a combination of essentially pure oxygen and CO 2 in at least some fired equipment involved in the production of hydrocarbons. Stack gases from such fired equipment may then be combined to consolidate CO 2 -producing streams. BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described, by way of example, with reference to the accompanying diagrammatic drawings in which FIG. 1 shows a process in accordance with the invention for a co-producing power and hydrocarbons; and FIG. 2 shows in more detail a portion of the process of FIG. 1 . DETAILED DESCRIPTION Referring to FIG. 1 of the drawings, reference numeral 10 generally indicates a process in accordance with the invention for co-producing power and hydrocarbons. The process 10 includes a coal-to-liquid (CTL) hydrocarbon synthesis facility generally indicated by reference numeral 12 and an Integrated Gasification Combined Cycle (IGCC) facility generally indicated by reference numeral 14 . The CTL facility 12 includes a dry gasification stage 16 , a gas clean-up stage 18 , a first Fischer-Tropsch hydrocarbon synthesis stage 20 , a second Fischer-Tropsch hydrocarbon synthesis stage 22 in series with the first Fischer-Tropsch hydrocarbon synthesis stage 20 , a heavy end recovery stage 24 , a water gas or sweet shift stage 26 , a CO 2 removal stage 28 , a hydrogen separation stage 30 , a reaction water treatment stage 32 and a product work-up stage 34 . A syngas line 36 leads from the dry gasification stage 16 to the gas clean-up stage 18 and from the gas clean-up stage 18 through the first and second Fischer-Tropsch hydrocarbon synthesis stages 20 , 22 . A Fischer-Tropsch tail gas line 38 leads from the second Fischer-Tropsch hydrocarbon synthesis stage 22 to the heavy end recovery stage 24 and from there to the water gas or sweet shift stage 26 , the CO 2 removal stage 28 and eventually to the hydrogen separation stage 30 . A hydrogen recycle line 40 leads from the hydrogen separation stage 30 back to the first Fischer-Tropsch hydrocarbon synthesis stage 20 and a fuel gas line 42 leads from the hydrogen separation stage 30 to the IGCC facility 14 . A syngas bypass line 44 bypasses the first Fischer-Tropsch hydrocarbon synthesis stage 20 . A sulphur recovery line 46 and a CO 2 line 48 leave the gas clean-up stage 18 . Hydrocarbon product lines 50 and reaction water lines 52 leave the first and second Fischer-Tropsch hydrocarbon synthesis stages 20 , 22 , with the reaction water lines 52 leading to the reaction water treatment stage 32 and the hydrocarbon product lines 50 leading to the product work-up stage 34 . The product work-up stage 34 is also connected to the heavy end recovery stage 24 by means of a light hydrocarbons line 54 leading from the heavy end recovery stage 24 to the product work-up stage 34 . An oxygenates line 56 and water lines 58 leave the reaction water treatment stage 32 , whereas an LPG line 60 , a naphta line 62 and a diesel line 64 leave the product work-up stage 34 . The CO 2 removal stage 28 is provided with a CO 2 line 66 . The IGCC facility 14 includes a wet gasification stage 70 , a sour shift stage 72 , a hydrogen-enriched gas expansion stage 74 , a gas clean-up stage 76 , a combustion gas expansion stage 77 , a gas combustion and expansion stage 78 and a waste heat recovery stage 80 comprising a co-fired waste heat boiler 82 and steam turbines 84 . A combustion gas line 86 leads from the wet gasification stage 70 to the gas clean-up stage 76 and from the gas clean-up stage 76 to the combustion gas expansion stage 77 and from there to the gas combustion and expansion stage 78 . The combustion gas line 86 between the wet gasification stage 70 and the gas clean up stage 76 also branches off to the sour shift stage 72 . An H 2 -enriched gas line 88 leads from the sour shift stage 72 through the hydrogen-enriched gas expansion stage 74 and joins the syngas line 36 between the dry gasification stage 16 and the gas clean-up stage 18 of the CTL facility 12 . A sulphur removal line 90 leaves the gas clean-up stage 76 . With reference to FIG. 2 of the drawings, the gas combustion and expansion stage 78 includes a compressor 92 and a gas turbine expander 94 drivingly connected to the compressor 92 . The combustion gas line 86 from the combustion gas expansion stage 77 leads to a combustor 96 . A CO 2 line 98 leads into the compressor 92 . A compressed CO 2 line 102 leads from the compressor 92 to the combustor 96 and is joined by an oxygen line 100 . A hot combusted gas line 104 leads from the combustor 96 to the gas turbine expander 94 . A hot exhaust gas line 106 leads from the gas turbine expander 94 to the co-fired waste heat boiler 82 of the waste heat recovery stage 80 . A steam line 108 leads from the co-fired waste heat boiler 82 to the steam turbines 84 and a condensate recycle line 110 leads back from the steam turbines 84 to the co-fired waste heat boiler 82 . The co-fired waste heat boiler 82 is joined by the fuel gas line 42 from the CTL facility 12 and is also provided with an exhaust gas line 112 . The hydrogen-enriched gas expansion stage 74 , the combustion gas expansion stage 77 , the gas combustion and expansion stage 78 and the steam turbines 84 provide electric power generally indicated by reference numeral 114 . Electricity can be exported and used internally, e.g. in the CTL facility 12 . The CTL facility 12 and the IGCC facility 14 share an air separation unit 120 , a CO 2 and water separation stage 122 , a CO 2 compression and water knock-out stage 124 and a water treatment stage 126 . The oxygen line 100 from the air separation unit 120 leads to the gas combustion and expansion stage 78 , as hereinbefore indicated, but also to other oxygen users in both the CTL facility 12 and the IGCC facility 14 . The CO 2 line 48 from the gas clean-up stage 18 of the CTL facility 12 leads to the CO 2 and water separation stage 122 and the CO 2 line 98 leads from the CO 2 and water separation stage 122 to the compressor 92 of the gas combustion and expansion stage 78 . A water line 128 leads from the CO 2 and water separation stage 122 to the water treatment stage 126 . The CO 2 compression and water knock-out stage 124 is joined by the exhaust gas line 112 from the waste heat recovery stage 80 and the CO 2 line 66 from the CO 2 removal stage 28 of the CTL facility 12 . A water line 130 leads from the CO 2 compression and water knock-out stage 124 to the water treatment stage 126 , which is also joined by the water line 58 from the reaction water treatment stage 32 of the CTL facility 12 . One or more treated water lines 132 , only one of which is shown for simplicity, leads from the water treatment stage 126 to both the CTL facility 12 and the IGCC facility 14 . Referring again to FIG. 2 of the drawings, the air separation unit 120 is provided with an air feed line 134 and a nitrogen production line 136 . Particulate coal is gasified in the dry gasification stage 16 to produce synthesis gas precursor. The dry gasification stage 16 may employ any conventional dry gasification technology, e.g. the Shell (trade name) entrained flow dry feed gasification technology which produces a synthesis gas precursor with an H 2 /CO molar ratio of about 0.4. Although not shown in the drawings, a waste heat boiler is used to cool the synthesis gas precursor, which is typically produced at a pressure of about 45 bar. The waste heat boiler produces process steam (not shown). The synthesis gas precursor is fed by means of the syngas line 36 to the gas clean-up stage 18 . The synthesis gas precursor is however first enriched in hydrogen by the H 2 -enriched gas flowing along the H 2 -enriched gas line 88 , thereby to increase the H 2 /CO molar ratio so that the H 2 /CO molar ratio is in the range of between about 0.7 and about 2.5. In the gas clean-up stage 18 the synthesis gas is cleaned in conventional fashion to remove sulphur, particulate material and CO 2 . Conventional synthesis gas cleaning technology may be used, e.g. a Rectisol process, amine washes and a CO 2 absorption process employing a Benfield solution. Sulphur is removed from the gas clean-up stage 18 by means of the sulphur recovery line 46 and the CO 2 is removed by means of the CO 2 line 48 . The clean synthesis gas is fed into the first Fischer-Tropsch hydrocarbon synthesis stage 20 and from there into the second Fischer-Tropsch hydrocarbon synthesis stage 22 to convert the synthesis gas to hydrocarbons. Any conventional Fischer-Tropsch hydrocarbon synthesis configuration may be used. In the embodiment shown in FIG. 1 of the drawings, a two-stage process employing a synthesis gas bypass (using the syngas bypass line 44 ) and a hydrogen recycle (using the hydrogen recycle line 40 ) is illustrated. The Fischer-Tropsch hydrocarbon synthesis stages 20 , 22 may thus include one or more suitable reactors such as a fluidised bed reactor, a tubular fixed bed reactor, a slurry bed reactor or an ebullating bed reactor. It may even include multiple reactors operating under different conditions. The pressure in the reactors may be between 1 bar and 100 bar but in this embodiment a pressure of about 45 bar is used. The temperature may be between 160° C. and 380° C. Reactors will thus contain a Fischer-Tropsch catalyst, which will be in particulate form. The catalyst may contain, as its active catalyst component, Co, Fe, Ni, Ru, Re and/or Rh, but preferable has Fe as its active catalyst component. The catalyst may be provided with one or more promoters selected from an alkaline metal, V, Cr, Pt, Pd, La, Re, Rh, Ru, Th, Mn, Cu, Mg, K, Na, Ca, Ba, Zn and Zr. The catalyst may be a supported catalyst, in which case the active catalyst component, e.g. Co, is supported on a suitable support such as Al 2 O 3 , TiO 2 , SiO 2 , ZnO or a combination of these. Preferably, the catalyst is an unsupported Fe catalyst. In the first Fischer-Tropsch hydrocarbon synthesis stage 20 and the second Fischer-Tropsch hydrocarbon synthesis stage 22 , reaction water is produced which is removed by means of the reaction water lines 52 and fed to the reaction water treatment stage 32 . In the reaction water treatment stage 32 oxygenates are separated from the reaction water using conventional separation technology and removed by means of the oxygenates line 56 . Water is withdrawn from the reaction water treatment stage 32 and fed to the water treatment stage 126 by means of the water line 58 . Hydrocarbon products produced in the first Fischer-Tropsch hydrocarbon synthesis stage 20 and the second Fischer-Tropsch hydrocarbon synthesis stage 22 are removed by means of the hydrocarbon product lines 50 and fed to the product work-up stage 34 . In the product work-up stage 34 , the hydrocarbon products are worked up to produce LPG gas, naphta and diesel, respectively removed from the product work-up stage 34 by means of the LPG line 60 , the naphta line 62 and the diesel line 64 . A Fischer-Tropsch tail gas is removed from the second Fischer-Tropsch hydrocarbon synthesis stage 22 by means of the Fischer-Tropsch tail gas line 38 and fed to the heavy end recovery stage 24 where light hydrocarbons, e.g. C 3 + hydrocarbons are removed in conventional fashion and fed by means of the light hydrocarbons line 54 to the product work-up stage 34 to be worked up with the hydrocarbon products entering the product work-up stage 34 by means of the hydrocarbon product lines 50 . The Fischer-Tropsch tail gas is then mixed with steam (not shown) and subjected to the well-known water gas shift reaction to convert CO and water (steam) to CO 2 and H 2 , in the sweet shift stage 26 . From the sweet shift stage 26 , the Fischer-Tropsch tail gas, now with an increased concentration of CO 2 and H 2 , is then fed to the CO 2 removal stage 28 . In the CO 2 removal stage 28 , conventional technology is again used to remove CO 2 and water from the Fischer-Tropsch tail gas. Typically, this includes the use of a Benfield solution to absorb the CO 2 . The CO 2 is then again desorbed and the CO 2 and water are removed from the CO 2 removal stage 28 by means of the CO 2 line 66 and fed to the CO 2 compression and water knock-out stage 124 . The Fischer-Tropsch tail gas from the CO 2 removal stage 28 , now with a reduced concentration of CO 2 and water, is fed to the hydrogen separation stage 30 . In the hydrogen separation stage 30 , conventional pressure swing adsorption is used to separate hydrogen from the Fischer-Tropsch tail gas, producing a fuel gas comprising mostly CO and hydrocarbon gasses. The hydrogen is recycled by means of the hydrogen recycle line 40 to the first Fischer-Tropsch hydrocarbon synthesis stage 20 . The fuel gas is removed by means of the fuel gas line 42 and fed to the waste heat recovery stage 80 of the IGCC facility 14 . Optionally, the fuel gas may be sold as synthetic natural gas and may also be blended with other gas streams to obtain the correct specification for sale. For purposes of generating power, a coal slurry is gasified in the wet gasification stage 70 of the IGCC facility 14 to produce combustion gas. Any conventional wet gasification technology may be used, such as the General Electric (trade name) slurry fed gasification technology. Water is used as a coal carrier so that a coal slurry is gasified resulting in an H 2 /CO molar ratio of about 0.96 in the combustion gas produced in the wet gasification stage 70 . The combustion gas is typically cooled using a water quench. The combustion gas is produced at a pressure of more than 70 bar. The combustion gas from the wet gasification stage 70 is removed by means of the combustion gas line 86 and fed to the gas clean-up stage 76 . Before the gas clean-up stage 76 , a portion of the combustion gas is mixed with steam as required (not shown) and diverted to the sour shift stage 72 where CO and water are converted to CO 2 and H 2 , using the well-known water gas shift reaction. An H 2 -enriched gas is thus produced in the sour shift stage 72 and the H 2 -enriched gas is fed by means of the H 2 -enriched gas line 88 to the hydrogen expansion stage 74 . In the hydrogen expansion stage 74 , the H 2 -enriched gas is expanded through an expansion turbine which drives a generator thereby to produce electrical power. In the expansion turbine, the pressure of the H 2 -enriched gas is dropped from more than 70 bar to about 45 bar, whereafter the H 2 -enriched gas is mixed with the synthesis gas precursor in the syngas line 36 to increase the H 2 /CO molar ratio of the synthesis gas precursor as hereinbefore described. In the gas clean-up stage 76 , the combustion gas is cleaned in conventional fashion to remove sulphur along the sulphur removal line 90 . The clean combustion gas is then fed to the gas combustion and expansion stage 78 by means of the combustion gas line 86 via the combustion gas expansion stage 77 . In the combustion gas expansion stage 77 , the clean combustion gas is expanded through a gas turbine expander, reducing the pressure of the combustion gas to the operating pressure of the gas combustion and expansion stage 78 , and generating electricity (generally indicated by reference numeral 114 ). Air is separated in the air separation unit 120 using conventional cryogenic air separation technology to produce nitrogen and oxygen, as shown in more detail in FIG. 2 . The nitrogen is removed by means of the nitrogen line 136 and employed in the CTL facility 12 and the IGCC facility 14 where required, or recovered for commercial purposes or purged. The oxygen from the air separation unit 120 is removed by the oxygen line 100 and also distributed to the CTL facility 12 and the IGCC facility 14 for use where required. A portion of the oxygen is fed by means of the oxygen line 100 to the combustor 96 of the gas combustion and expansion stage 78 (see FIG. 2 ). In the CO 2 and water separation stage 122 , water is knocked from the CO 2 . The water is fed by means of the water line 128 to the water treatment stage 126 . The CO 2 is removed from the CO 2 and water separation stage 122 and fed to the compressor 92 of the gas combustion and expansion stage 78 . CO 2 in the CO 2 line 98 is thus fed to the compressor 92 and compressed. The compressed CO 2 is mixed with high pressure oxygen from the oxygen line 100 and the compressed CO 2 and oxygen mixture is fed by means of the compressed CO 2 and oxygen line 102 to the combustor 96 . Combustion gas fed by means of the combustion gas line 86 is combusted in the combustor 96 , in the presence of the CO 2 and oxygen to produce a hot combusted gas. The hot combusted gas is removed by means of the hot combusted gas line 104 and passed through the gas turbine expander 94 which inter alia drives the compressor 92 by means of a direct mechanical coupling. The gas turbine expander 94 is also used to drive generators (not shown) to generate electric power generally indicated by reference numeral 114 . A hot exhaust gas, comprising mostly CO 2 and water, is removed from the gas turbine expander 94 by means of the hot exhaust gas line 106 and fed to the co-fired waste heat boiler 82 of the waste heat recovery stage 80 . The waste heat boiler 82 is fired with fuel gas fed by means of the fuel gas line 42 and produces high pressure steam which is fed by means of the steam line 108 to the steam turbines 84 which are used to drive generators (not shown) to generate electric power generally indicated by reference numeral 114 . Condensate is recycled from the steam turbines 84 to the co-fired waste heat boiler 82 . The gas turbine expander 94 and/or the steam turbines 84 may be integrated with the air separation unit 120 to drive air compressors of the air separation unit 120 by means of direct mechanical coupling. In the co-fired waste heat boiler 82 , the exhaust gas produced by the combustion of the fuel gas is combined with the exhaust gas from the gas turbine expander 94 and removed by means of the exhaust gas line 112 . As will be appreciated, this exhaust gas comprises mostly CO 2 and water. The exhaust gas is fed to the CO 2 compression and water knock-out stage 124 where it is compressed. Water is knocked out from the compressed CO 2 and fed by means of the water line 130 to the water treatment stage 126 . The compressed CO 2 from the CO 2 compression and water knock-out stage 124 is available for sequestration or capture, as indicated by reference numeral 134 . The compressed CO 2 may thus for example be employed for enhanced oil recovery (EOR) or enhanced coal-bed methane recovery (ECBMR). In the water treatment stage 126 , water fed to the water treatment stage 126 along the water lines 58 , 128 and 130 are treated to requisite levels. The treated water is removed by means of the treated water lines 132 and distributed to both the CTL facility 12 and the IGCC facility 14 , inter alia to be used as boiler feed water. Selecting a gasification technology best suited to a particular venture involves consideration of various factors, including feedstock characteristics, capital cost, operating cost, reliability, intended application of the produced synthesis gas, etc. The invention, as illustrated, provides an integrated IGCC power plant and CTL plant which benefit from optimal economies of scale of the capital intensive parts and also provides for CO 2 sequestration. A combination of dry gasification and wet gasification is used to provide intermediate streams suited to hydrocarbon synthesis and power production respectively. Advantageously for power production, a wet gasification process can supply combustion gas at pressures higher than 70 bar. A dry gasification process can supply synthesis gas precursor at pressures matching the requirement for Fischer-Tropsch hydrocarbon synthesis, typically around 45 bar. The combustion gas typically has a higher hydrogen content than the synthesis gas precursor, a portion of the combustion gas thus providing a suitable feed material for enrichment with hydrogen to upwardly adjust the molar ratio of H 2 and CO of the synthesis gas precursor. Furthermore, the wet gasification stage typically employs a water quench and the combustion gas is thus saturated with water at relatively high temperature. Advantageously, the steam requirement of the sour shift used to enrich the first portion of the combustion gas with hydrogen is thus reduced. In addition, the dry gasification stage typically employs a waste heat boiler providing process steam. Overall energy efficiency is thus enhanced by the combination of dry- and wet gasification technologies, because the dry gasification approach is more efficient at producing a synthesis gas rich in carbon monoxide and the required process steam, while the wet gasification process is the most efficient approach to produce an enriched hydrogen gas. Advantageously, the IGCC facility may be appropriately sized for internal consumption of energy only or, instead, if there is a suitable market for electricity in the vicinity, the IGCC facility may be sized to maximise economy of scale for the export of power. Air separation units are expensive to construct and energy-intensive to operate due to large compression requirements. Advantageously, when an IGCC facility and a CTL facility share an air separation unit, economy of scale lowers the cost per unit volume of oxygen required by the CTL facility. Power-producing turbines of the IGCC facility may be integrated by direct mechanical coupling to air compressors of the air separation unit, resulting in improved plant energy efficiency, since a loss in efficiency associated with electrical power generation is avoided. Sharing of utilities lowers the cost of expensive ultra-pure water used as boiler feed water make-up to produce steam for use in the steam turbines in the IGCC facility. Savings can also be realised in utility costs for the CTL plant because of better economies of scale. Fuel gas produced by the CTL facility, which in many cases would be purged, can be used as fuel in the IGCC facility, e.g. in heat recovery units of the IGCC facility. This allows the production of steam at a higher pressure and/or a higher temperature. As the fuel gas will come as internal transfer from a large scale facility, costs will be reduced. From the perspective of the CTL facility, this option provides an internal and assured consumer for the fuel gas stream. Power for internal consumption on the CTL facility is generated at optimal cost and efficiency, improving the overall carbon and plant efficiency of the integrated CTL and IGCC facilities compared to that of two stand-alone facilities. Finally, the integration of a CTL facility and an IGCC facility allows capturing of CO 2 from the off-gas of the IGCC facility. This is achieved by directing a portion of the CO 2 produced in the CTL facility, to the compressor of the gas turbine expander of the IGCC facility, together with pure oxygen from an air separation unit, thereby avoiding the introduction of nitrogen into the combustor of the IGCC facility. This allows the gas turbine to be run using a mixture of oxygen and CO 2 instead of a conventional mixture of oxygen and N 2 when air is used. The final off-gas from the IGCC facility will thus be a relatively pure combination of CO 2 and water vapour, which can be combined with the remaining CO 2 produced by the CTL facility for export, allowing the CO 2 processing and compression facilities to benefit from an increased economy of scale.

A process ( 10 ) for co-producing power and hydrocarbons includes in a wet gasification stage ( 70 ), gasifying coal to produce a combustion gas ( 86 ) at elevated pressure comprising at least H 2 and CO; enriching ( 72 ) a first portion of the combustion gas with H 2 to produce an H 2 -enriched gas ( 88 ); and generating power ( 77 ) from a second portion of the combustion gas. In a dry gasification stage ( 16 ), coal is gasified to produce a synthesis gas precursor ( 36 ) at elevated pressure comprising at least H 2 and CO. At least a portion of the H 2 -enriched gas ( 88 ) is mixed with the synthesis gas precursor ( 36 ) to provide a synthesis gas for hydrocarbon synthesis, with hydrocarbons being synthesized ( 20, 22 ) from the synthesis gas. In certain embodiments, the process ( 10 ) produces a CO 2 exhaust stream ( 134 ) for sequestration or capturing for further use.

big_patent

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for preparing a solid device for use as an oxide superconducting material, and more particularly to a method for preparing a solid device, the surface of which is utilized for oxide superconducting material wherein an important improvement is imparted to the properties of the material at the surface o portion close to the surface. to provide a highly reliable surface utilizing-device. 2. Description of the Related Art Recently, considerable attention has been directed toward oxide superconducting materials. This began with the development of a Ba--La--Cu--O type of oxide superconducting material in the IBM research laboratories in Zurich, Switzerland. In addition to this, an yttrium type of oxide superconducting material is also known, which has provided the obvious possibility for the practical application of a solid device at the temperature of liquid nitrogen. On the other hand, superconducting materials using metals such as Nb 3 Ge have been well known conventionally. Trials have been conducted in fabricating solid devices such as the Josephson element using this metal superconducting material. After a dozen years of research, a Josephson device using this metal is close to being realized in practice. However, the temperature of this superconducting material at which the electrical resistance becomes zero (which is hereinafter referred to as Tco) is extremely low, that is 23 %, so that liquid helium must be used for cooling. This means that practical utility of such a device is doubtful. With a superconducting material made of this metal, the components on both the surface and in the bulk of the material can be made completely uniform because all the material is metal. On the other hand, when the characteristics of the oxide superconducting material which has been attracting so much attention recently are examined, a deterioration of the characteristics (lowering of reliability) is observed at the surface or portion close to the surface (roughly 200 Å deep), in comparison with the bulk of the material. It has been possible to prove experimentally that the reason for this is that the oxygen in the oxide superconducting material can be easily driven off. Further, when observed with an electron microscope, an empty columnar structure is seen with an inner diameter of 10 Å to 500 Å, and usually 20 Å to 50 Å in the oxide superconducting material, and in other words, the oxide superconducting material is found to be a multiporous material having indented portions in micro structure. For this reason the total area at the surface or portion close to the surface is extremely large, and when this oxide superconducting material is placed in a vacuum, the oxygen is broken loose as if absorbed gas was driven off. The basic problem is determined that whether the material has superconducting characteristics or simply normal conducting characteristics is dependent on whether the oxygen is present in ideal quantities or is deficient. SUMMARY OF THE INVENTION An object of the present invention is to provide, with due consideration to the drawbacks of such conventional devices, a method for preparing a superconducting device which is kept superconductive at the surface or portion close to the surface of the oxide superconducting material. This is accomplished in the present invention by the provision of a blocking film (passivation film), which is uniformly coated over the spaces or micro-holes in the surface portion of the superconducting material, to prevent the removal of oxygen from that surface. BRIEF DESCRIPTION OF THE DRAWINGS These and other objects, features, and advantages of the present invention will become more apparent from the following description of the preferred embodiments taken in conjunction with the accompanying drawings, in which: FIG. 1(A) to FIG. 1(E) are a diagram indicating the method of preparing the superconducting device of the present invention and showing the distribution of the oxygen concentration. FIG. 2(A) and FIG. 2(B) are an enlarged sectional drawing of a superconducting material for implementing the method of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the embodiments of the present invention, a blocking film or passivation film is uniformly coated over the spaces or micro-holes in the surface portion of the superconducting material to prevent the removal of oxygen from that portion. Subsequently, a means is added by which the amount of oxygen in the inside surfaces of the superconducting material which tend to become oxygen deficient, can be precisely controlled. The superconducting material therefore has the same conductivity characteristics at the surface portion as at the internal portion. In the present invention, a film is formed on the surface of the superconducting material at a thickness of 10 Å to 2μm using an photo CVD method superior in stepped coverage, which is a method of exciting a reactive gas using ultraviolet light for coating a film onto a film forming surface. In particular, if this film is to be an insulated or half-insulated film for use in a Josephson element, it is formed at a thickness of 10 Å to 10 Å. Also, in the case where it is to be used as a passivation film, it is formed in a thickness of from 1000 Å to 2 μm. After this, by means of methods such as the ion injection method or hot oxidation method, oxygen is added onto the surface or portion close to the surface, and the entire body is heat treated, so that the added oxygen is positioned in the appropriate atom location. In addition, this film is converted by heat treatment to a highly dense insulating material to provide a more complete blocking layer. This film is oxidized on a metal or semiconductor and is formed to function as an insulating film. Further, by solid phase to solid phase diffusion of the oxygen in this film, that is diffusion of the oxygen from a solid film into another ceramic which is solid, the oxygen concentration in the region at the surface or close to it, generally at a depth of about 200 Å, can be appropriately controlled. The films used for this purpose may be insulating films such as silicon nitride, aluminum nitride, oxidized aluminum, oxidized tantalum, oxidized titanium and the like. In addition, a metal or semiconductor which becomes an oxidized insulating film after oxidizing treatment can be used as this film. Specific examples are, in a metal, aluminum, titanium, copper, barium, yttrium, or in a semiconductor, silicon or germanium. These materials, by oxidation, can be made into aluminum oxide, titanium oxide, tantalum oxide, copper oxide, barium oxide, and yttrium oxide. Also, silicon can be converted into silicon oxide, and germanium into germanium oxide. With the present invention, an oxide superconducting material formed into tablets, or a superconducting material formed into a thin film can be used. Especially with the use of a thin film structure, the screen printing method, sputtering method, M8E (molecular beam epitaxial) method, CVD (chemical vapor deposition) method, photo CVD method, and the like can be used. One example of an oxidized superconducting material used in the present invention can be generally represented as (A 1-x B x ) y Cu z O w , where x=0 to 1, y=2.0 to 4.0 or, preferably, 2.5 to 3.5, z=1.0 to 4.0 or, preferably, 1.5 to 3.5, and w=4.0 to 10.0 or, preferably, 6.0 to 8.0. A is one or a plurality of elements which can be selected from the group of Y (yttrium), Gd (gadolinium), Yb (ytterbium), Eu (europium), Tb (terbium), Dy (dysprosium), Ho (holmium), Er (erbium), Tm (thulium), Lu (lutetium), Sc (scandium), and other elements in Group III of the Periodic Table. B can be selected from among elements in Group IIa of the Periodic Table, such as Ra (radium), Ba (barium), Sr (strontium), Ca (calcium), Mg (magnesim), and Be (beryllium). In particular, as a specific example, (YBa 2 )Cu 3 O 6-8 can be used. In addition, lanthanide elements or actinide elements in the Periodic Table other than those outlined above can be used as A. In the present invention, when the insulating film is of a thickness capable of causing a tunnel current of 5 Å to 50 Å to flow, another superconducting material can be positioned on the upper surface of this insulating film to provide a Josephson element structure. In addition, it can also be used as a passivation film, that is a film to prevent deterioration, at a thickness of from 1000 Å to 2 μm. Specifically, after the film is formed on the oxide superconducting material, oxygen can be added, or, added oxygen can be positioned in an appropriate location, by use of a heat treatment at from 300° C. to 900° C., for example 600° C., for 0.5 to 20 hours, for example, 3 hours, in an atmosphere of inert gas, air, or oxygen, so that the surface of the material or the portion close to the surface can be superconductive. As a result, the oxygen concentration of this surface can be maintained in an ideal status when maintained at the temperature of liquid nitrogen. Specifically, a passivation film can be created. In this way, the problem which has existed up until the present time, that is, the problem that the superconducting state close to the surface of an oxide superconducting material disappears for unknown causes, is corrected, and the superconductive state of the surface can be effectively utilized with long-term stability. As a result, the surface utilizing device, especially a Josephson element, can be activated with long term stability and high reliability. FIRST EXAMPLE Now referring to FIG. 1(A) to FIG. I(E), the structure of a first example of the present invention and the characteristics of the relative distribution of the concentration of oxygen in this embodiment are shown. FIG. 1(A) shows a superconducting material, for example YBa 2 Cu 3 O 6-8 . The copper component may be 3 or less. The starting material (FIG. 1(A)(1)) was formed from such a superconducting material in tablet or thin film form, having a monocrystalline or polycrystalline structure. When this material was placed in a vacuum in a vacuum device, the oxygen in the area close to the surface (1) was removed, so that the deterioration of electrical characteristics occurred in a depth range up to about 2OO Å. When this surface was observed through an electron microscope, deep spaces or micro-holes were seen to be formed from the surface to the interior of the material, as shown in FlG. 2 (A). These spaces have an internal diameter of 10 Å to 500 Å, and usually from 20 Å to 50 Å. The oxygen density corresponding to FIG. 1(A) is shown in FIG. 1(D). And, it has been confirmed that the oxygen at the surface or close to the surface can be easily removed. A region 1 in the diagram had a normal oxygen concentration, while there was a deficiency of oxygen in a region 1'. The depth of the region 1' with a deficiency of oxygen was 50 Å to 2000 Å. This depth varied depending on the type, structure, and density of the superconducting material, but was generally about 200 Å. On the surface of this material, a silicon nitride film, a silicon oxide film, or an aluminum film was formed to a depth of 5 Å to 50 Å, for example, 20 Å, by the CVD method, in which a reactive gas is optically excited using ultraviolet light or a laser beam, so that a film is formed on the treated surface. The silicon nitride was formed at a temperature of 250° C. and a pressure of 10 torr, from the following reaction: 3Si.sub.2 H.sub.6 +8NH.sub.3 →2Si.sub.3 N.sub.4 +21H.sub.2 In this way, it was possible to form a film so that the inside of the spaces was adequately coated. In addition to this treatment, ion injection was also carried out. A lower accelerating voltage of 10 KV to 30 KV was applied and doping was carried out, so that the oxygen concentration became uniform at a concentration of 1×10 17 cm -3 to 1×10 21 cm -3 . Heat treatment was applied to the whole body in an atmosphere of oxygen at 300° C. to 900° C., for example 500° C. for about 5 hours. As a result of this heat treatment, it was possible to impart the same oxygen density to the surface portion as in the internal portion as shown in FIG. 1(E). A sample of this embodiment of the present invention was removed from the heat treatment condition and once more stored in a vacuum. A blocking layer 3 formed in this manner on the surface or portion close to the surface of the superconducting material made it possible to produce a highly reliable device, with no oxygen deficiency in that portion. This insulating film was extremely effective as a passivation film. SECOND EXAMPLE In a second example of the present invention, silicon oxide was used for the film. The silicon oxide was formed at a temperature of 200° C. using ultraviolet light at 185 nm and a pressure of 20 torr, implementing a photochemical reaction as indicated in the following equation : SiH.sub.4 +4N.sub.2 O→SiO.sub.2 +4N.sub.2 +2H.sub.2 O The superconducting material was the same as in the first example. Subsequently, a heat treatment in oxygen at 460° C. was carried out and a suitable oxygen concentration obtained. THIRD EXAMPLE In a third example of the present invention, metallic aluminum was used for the film. The aluminum film was formed at a temperature of 250° C. and a pressure of 3 torr, using a photo-CVD process at a wavelength of 185 nm, implementing a photochemical reaction as indicated in the following equation : 2Al(CH.sub.3).sub.3 +3H.sub.2 +2Al+6CH.sub.4 Subsequently, the material was annealed in oxygen at 500° C. for 3 to 10 hours, and, as in the first example, the aluminum on the surface was converted to alumina, and the concentration of oxygen was optimized throughout the superconducting material. An oxide superconducting material is used in the present invention, and the surface, when examined with a electron microscope, is seen to have a large number of micro-holes or spaces. It is necessary to fill the inside of the spaces or the micro-holes with a solid material to have a high degree of reliability. A film produced by the vacuum evaporation method, hot CVD method, sputtering method and the like cannot cover the internal surface. However, when the photo-CVD method is used in the present invention, an extremely superior coating is possible, so that an extremely minute coating can be obtained on the top surface of the porous substrate material used. In addition, by making this coating more dense, or converting to an oxidized insulating material, a more perfect state can be obtained, and at the same time it is possible to fill the microholes or spaces. In addition, this method by which an improved, dence, superconducting material is obtained is extremely effective because the manufacturing process is very easy. In the present invention the term "oxide superconducting material" is used, wherein it is clear that in the technical concept of the present invention, the crystal structure may be either monocrystalline or polycrystalline. In particular, in the case of a monocrystalline structure, epitaxial growth may occur on the substrate for use as the superconducting material. In the present examples, after the film has been formed, oxygen is injected into the superconducting material by ion injection. However, it is possible to add oxygen to the surface or portion close to the surface of the superconducting material in advance by the ion injection method or the like, and the form the film afterward, before effectively positioning the added oxygen in the appropriate atom location by a hot oxidation process when fabricating the superconducting material.

A method for manufacturing a superconducting device comprises the steps of forming a passivation film by photo chemical vapor deposition on the surface of an oxide superconducting material; and then adding oxygen into the oxide superconducting material by ion injection. This patent application is related to the copending U.S. Pat. application entitled "Method of Adding a Halogen Element Into Oxide Superconducting Materials by Ion Injection" Ser. No. 190,352, filed May 5, 1988, now U.S. Pat. No. 4,916,116.

big_patent

BACKGROUND OF THE INVENTION The present invention relates to the manufacture of foam sheet stock used in a wide variety of applications, such as for example containers, meat trays, packaging materials and antifriction place mats for airlines food service. During the manufacture of foam sheet stock from materials such as polystyrene, polyethylene and the like, it is well known to introduce the basic polymer or copolymers into one or more extrusion devices in order to heat the polymer and incorporate therein certain nucleating agents, as well as the blowing agent. The thoroughly heated and masticated plastic material is then extruded through an extrusion orifice into a thin sheet or preferably a tube. When the extrudate takes the shape of a tube, it is drawn over a mandrel, thus expanding the circumferential extent of the tube. In addition, the tube of foam material is pulled away from the mandrel at a speed greater than the extrusion speed, thus inducing a certain amount of orientation into the foam sheet material. The orientation in a cellular foam sheet is a desirable feature in that certain memory characteristics can be built into the foam sheet. For example, it is now common to sever rectangular shaped pieces of foam sheet material and form them into cylinders having an overlapped liquid impervious seam. The cylinder thus formed is placed on a mandrel and subjected to controlled heat, thus causing the foam material to shrink and assume the configuration of the mandrel. Both one and two-piece drinking cups have been manufactured in this manner. Then too, a protective cover for bottles has been used for several years in the carbonated beverage field. In order to monitor newly created foam sheet material, it is highly desirable to be able to examine in minute detail the actual cell structure within the sheet. Microscopic examination at, for instance, 60X magnification reveals several important aspects of how well the foam sheet has been fabricated. For example, it is highly important that the individual cells be of closed configuration if the ultimate purpose of the sheet material is for the fabrication of containers such as coffee cups and the like. A close-up examination of the cells within the sheet material reveals how well the surfaces of the foam material have been cooled. If the cooling is too rapid, small cell sizes will be created, thus acting as a bar to adequate cooling of the cells situated in the center of the sheet. Cells that receive inadequate cooling will have a tendency to rupture, thus reducing the overall integrity and usefulness of the sheet material. A good microscopic examination will reveal whether there has been an overload of the blowing agent and in the instance of a laminate, the skin thickness and uniformity can be monitored. A microscopic examination also permits an insight into the physical dimensions of each cell within the foam structure and its relationship with adjacent cells. As a foam material is generated soon after extrusion, the cells are normally spherical in configuration. With the introduction of orientation into the foam material, the originally spherical cells assume an elongate shape which they retain until subsequently released by the application of heat. Thus it becomes evident for several reasons to rely upon good microscopic examination of the individual cell structure in foam sheet material to assure adequate quality control. SUMMARY OF THE INVENTION The present invention relates to an apparatus for the preparation of foam sheet samples for microscopic examination. More particularly, the invention relates to an apparatus that permits a precisely measured laboratory foam sheet cross-sectional specimen to be prepared. Foam sheet stock suitable for the manufacture of containers such as coffee and soft drink cups has an overall thickness in the range of 0.015 inch to 0.040 inch and a density of 10-15 pounds per cubic foot. Consequently, it is difficult to sever a thin parallel sided strip of foam sheet so that its edge structure can be examined microscopically. To cut such samples by the use of tools, such as scissors, would crush the delicate cell structure to such an extent that a detailed examination of the exposed sheet edge would not be meaningful. Thus it becomes imperative that the foam sheet samples be severed by means of a thin cutting blade such as a razor blade. With this in mind it is one of the objects of the present invention to provide an apparatus that will grasp a foam sheet sample and permit a series of very linearly oriented parallel cuts to be made thereon. The present apparatus includes a base structure for stabilization of the device and a clamping arrangement to grasp the foam sheet specimen without damaging it to the extent samples cannot be severed therefrom. The foam sheet can be advanced through the apparatus a prescribed amount and a planar surface is provided for the interaction with a cutting knife. Since the apparatus employs a screw thread specimen advance mechanism, it is possible to prepare repetitive samples, each having a uniform thickness with very parallel cut edges exposed for microscopic examination. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the sample preparation apparatus of the present invention. FIG. 2 is a fragmentary sectional view, taken along lines 2--2 of FIG. 1 which shows the bottom tie-down connection for the hand nut. DESCRIPTION OF THE PREFERRED EMBODIMENT The apparatus of the present invention is shown in FIG. 1. The overall apparatus is represented by numeral 10. The apparatus 10 represents a compact device for manipulating a foam sheet sample such as that depicted at 12. The foam sample 12 is prepared for use with apparatus 10 by first cutting it to a rectangular configuration. In particular, apparatus 10 is supported by a base plate 14. Base plate 14 is generally rectangular in shape and is preferably constructed of metal. Two upright support columns 16 and 18 are attached to the top planar surface of base plate 14. The tops of support columns 16 and 18 are tied together by means of top deck plate 20. A support bar 22 is attached to the top surface of top deck plate 20 and is cantilevered so that it extends in a horizontal direction over the base plate 14. A clamp bar 24 is positioned adjacent one side of support bar 22 and is held in aligned engagement with support bar 22 by means of the threaded studs 26 and 28 which are anchored in support bar 22. Wing nuts 30 and 32 which coact with studs 26 and 28 provide a means for moving clamp bar 24 against support bar 22. The manner of use and function of the clamp bar 24 positioning and its use will be explained in more fully infra. Returning once again to base plate 14, vertically aligned posts 34 and 36 are oriented to one another in spaced apart parallel positioning which is also perpendicular to base plate 14. Posts 34 and 36 are attached to the top of base plate 14 by conventional means (not shown). The top section 38 of posts 34 and 36 are of reduced diameter and coact with the bifurcated ends of saddle bar 40. Thus, as shown in FIG. 1, the saddle bar 40 is restrained from rotation by the engagement provided by posts 34 and 36. However, saddle bar 40 has freedom of movement in a vertical direction. Saddle bar 40 is rigidly attached, by a fastener such as bolt 42, to the top surface of threaded member 44. Threaded member 44 is of cylindrical configuration and is threaded with a low pitch thread on its exterior. An internally threaded hand nut 46 contains a centrally positioned internal bore that is threaded to match the threads on threaded member 44. Hand nut 46 is adapted for rotation both clockwise and counterclockwise and is rotatably anchored to base plate 14. FIG. 2 which is a fragmentary cross-sectional view, further shows how hand nut 46 is attached to the top of base plate 14. An aperture 48 is placed in the bottom center of hand nut 46. A pivot pin 50 is passed through aperture 48, as well as a similar diameter aperture in bushing 52. Bushing 52 is pressed into an accommodating hole in base plate 14. The bushing 52 contains a flange 54 that provides sufficient space between the bottom of hand nut 46 and the top of base plate 14 so that there is no interference as hand nut 46 is rotated. The lower end of pivot pin 50 is grooved for the reception of a retaining ring 56 as shown in FIG. 2. Since hand nut 46 is held captive by means of pivot pin 50, its movement in the vertical direction is zero. However, when hand nut 46 is rotated, threaded member 44 will move in an upward or downward direction depending upon which direction hand nut 46 is rotated. Hand nut 46 has a large diameter flange-like disc 58 incorporated as an integral part of its lower extremity. Disc 58 is of sufficient overall diameter and thickness that it can be easily manipulated by hand. To further aid in the rotation of disc 58, notches 60 are positioned in a circumferentially spaced array around the periphery of disc 58. Interdispersed between notches 60 are bushings 62 which are carefully laid out so that the circumferential spacing therebetween is in equal increments. Each bushing 62 is in radial alignment with respect to the axis of rotation of hand nut 46. A detent mechanism 64 is positioned outboard of hand nut 46 and in radial alignment with the rotational axis of hand nut 46. The leading edge of detent mechanism 64 is adapted to enter bushings 62, thus securing hand nut 46 from rotation so long as the detent is engaged. The detent mechanism 64 is spring biased (not shown) and is operated by applying a radially outward force to the handle. The detent mechanism 64 is held in position by post 66 which is fastened to base plate 14. Directing our attention once again to saddle bar 40, which is affixed to the top of threaded member 44, a lower clamp mechanism 68 is mounted on the top of saddle bar 40. The lower clamp mechanism 68 is positioned beneath the upper support bar 22. A clamp block 70 is attached to saddle bar 40 and its inboard face is in vertical alignment with the inboard face of support bar 22. A movable clamp pad 72 is positioned so that it will coact with clamp block 70. The clamp block 70 is attached to the end of screw 74. The attachment of screw 74 to clamp block 70 permits screw 74 to rotate without clamp block 70 also rotating. Screw 70 is held in position and in threaded engagement with support post 68. A convenient handle 78 is attached to screw 74 to facilitate the movement of clamp pad 72 into and out of clamping engagement with clamp block 70. During the operation of overall apparatus 10, a foam sample, such as that depicted at 12, is sheared to a rectangular size that will permit it to be inserted in the expanse between studs 26 and 28 of support bar 22. The foam sample 12 is accommodated in the space between support bar 22 and clamp bar 24 and is lowered until its bottom edge rests firmly against the top surface of saddle bar 40. The foam sample 12 also passes between the gripping surfaces of clamp block 70 and coacting clamp pad 72. After the foam sample 12 has been positioned as described abovee, the lower clamp pad is moved into firm engagement with foam sample 12, thus clamping it into an immobile position with respect to saddle bar 40. The top clamp bar 24 is moved into engagement with foam sample 12, however, care is taken to only exert enough force to remove the slight curl which is inherent in foam sheet stock samples. This force is achieved by slowly tightening wing nuts 30 and 32 so that clamp bar 24 maintains its parallel orientation with respect to support bar 22. Thus when clamp bar 24 is in final position, it will have removed the curvature or curl from foam sample 12, yet it will not impede the free movement of foam sample in the vertical direction. At this point in the test procedure and sample preparation, it is desirable to permit an excess of foam sheet 12 to protrude above the top surfaces of support bar 22 and clamp bar 24. The hand nut 46 can, for example, be placed at stop position number 1 by removing detent mechanism 64 and reinserting it in the bushing 62 corresponding to position number 1 when the overall apparatus 10 and its included foam sample are in a position thus described above. A sharp instrument, such as a razor blade, is used to cut and remove that portion of foam sample 12 that protrudes above the surfaces of support bar 22 and coacting clamp bar 24. To assure an even cut across the expanse of foam sample 12, the cutting edge of the razor blade is held against the surfaces of support bar 22 and clamp bar 24. The just mentioned surfaces are at the same elevation, thus assuring that the newly cut surface of foam sample 12 is perpendicular to its planar side surfaces. The hand nut 46 is freed from its locked position by retracting detent mechanism 64. Hand nut 46 is repositioned at stop position number 2. The slight turn of hand nut 46 from stop position 1 to stop position 2 results in the raising of foam sample 12 by 0.004 inch. This specific increment in the raising of the top edge of foam sample 12 above the top surfaces of support bar 22 and clamp bar 24 is achieved because of the following arrangement. The 0.004 inch rise of saddle bar 40 and its attached foam sample 12 is attributable to the laying out of the center lines of bushings 62 at angles of 25.714 degrees which results from 360 degrees divided by 14 equal stop positions. The thread employed on threaded member 44 is an 18 pitch thread, thus one revolution divided by 14×18 equals 0.00396 inch or when rounding off, 0.004 inch. After hand nut 46 has been advanced to stop position 2, the razor blade is once again utilized to sever a 0.004 inch thick slice of foam material from the top edge of foam sample 12. The 0.004 inch sample is then carefully removed and mounted on double sticky back tape on a microscope slide. If foam samples of greater thickness are desired, hand nut 46 is advanced more than one stop, thus resulting in sample thicknesses which are multiples of 0.004 inch. Thus the present invention provides samples for another physical test in addition to other tests such as tensile, stretch, elongation, solvent resistance and surface cell size. The present invention permits test samples to be prepared which is an aid to establish performance criteria, for example, two foam materials may appear equal in physical tests, as well as in residual blowing agents, yet one foam material may be brittle and the other flexible or two different foam materials of the same caliper and density may vary as to their respective insulative qualities. An insight as to the differences between such foam materials can be gained by examining the precisely cut foam samples as prepared by the present invention. Then too, the method provided by the present invention provides for the severing of foam test samples that have at least two cut sides that are parallel to one another. The present method preserves the structure of the individual cells within the sample so that the cells may be examined without undue distortion or mutilation occurring because of the sample preparation. The precise parallel orientation of the cut surfaces of the foam samples permits even transmission of light through the specimen during its microscopic examination.

A device for aiding in the preparation of very thin slices of foam sheet material that is to be examined under a microscope. The device has a clamp arrangement for holding a sample of foam sheet material. A screw feed arrangement permits the foam sheet material to be advanced past a planar surface where a very thin slice of foam material can be removed. A clamping arrangement keeps the foam sheet material in linear alignment at the location where the sample is severed. A detent arrangement permits a metered amount of foam sheet material to be advanced past the planar cutting surface by the screw feed arrangement. The method of preparing a foam sample by first severing the foam material while it is held by the apparatus, thus establishing a planar cut, then positioning the material for a second cut which is then made parallel to the first cut.

big_patent

BACKGROUND OF THE INVENTION This invention relates to seismometers, especially those designed to operate on the ocean floor, and more particularly to a method and apparatus for determining the angle of inclination with respect to the vertical assumed by such a unit during its operation and for leveling the seismic motion detectors carried by such a unit. Seismometers have become an integral component of geological research, especially oil and natural gas exploration. More recently a number of seismometers, commonly referred to as "ocean bottom seismometers" ("OBS's"), have been especially designed and built for remote operation on the ocean's floor in conjunction with such exploration. In such operations a seismic disturbance is artificially generated to create seismic shockwaves which pass through the earth and are refracted at interfaces of rock having diffusing densities. The refracted waves propate back to the earth's surface where they are sensed by seismic motion detectors carried in the seismometer. The use of OBS's poses certain problems not generally encountered in dry land seismometer operations. In seismic exploration on land, the persons deploying the seismic motion detector(s) used can take care to position it (them) so as to provide good seismic coupling to the earth. OBS's used today in deep water exploration are positioned either by being lowered on cables or, more generally, by being dropped in free fall from the ocean's surface. The user has minimal control over the placement of the OBS and generally has no idea of the precise nature of the surface on which the OBS has come to rest. Often, the OBS lands in a position which might not provide good coupling to the seismic waves which it is intended to record. The present invention is a simple and inexpensive method for determining the angle of inclination with respect to the vertical (hereinafter referred to simply as "the angle of inclination") assumed by a seismometer in its operating position, such as an OBS on the ocean floor, and an apparatus for preserving the orientation assumed by the seismometer for later measurement of that angle. Knowing the angle of inclination gives the user some idea of the contour of the ocean floor on which the OBS has fallen. This knowledge can also be used with other available information in later constructing the precise location of the unit on the ocean floor and in evaluating the data gathered and the causes of any failure to obtain data or suitable data. The present invention also assures good coupling of the seismic motion detector to the framework of the seismometer resting directly on the ocean bottom through which the seismic waves travel. The present invention also comprises a method and apparatus for automatically leveling seismic motion detectors employed in a seismometer. Seismic motion detectors such as geophones are commercially available from numerous commercial sources and are in themselves beyond the scope of this invention. Generally, each such detector has a preferred "operating axis", either vertical or horizontal and will sense the component of motion occurring along an axis parallel to its operating axis. Thus, three orthogonally positioned detectors, one vertical and two horizontal, are needed to fully sense all components of seismic motion. Depending upon the nature of the geological investigation being undertaken, as few as one detector may be used. Means must be provided to align the vertically and horizontally operating detectors, where used, parallel and perpendicular to the vertical, respectively, for operation. Because of the nature of their remote operation, OBS's require self-leveling means for their seismic detectors. The use of gimbal arrangements for leveling OBS seismic motion detectors has been described by T. J. E. Francis et al., in the article "Ocean Bottom Seismograph", published in Marine Geophysical Researches 2 (1975), pp. 195-213 and by S. H. Johnson et al., in the article "A Free-Fall Direct-Recording Ocean Bottom Seismograph", published in Marine Geophysical Researches 3 (1975), pp. 103-117. Rex V. Johnson II et al., in the article "A Direct-Recording Ocean Bottom Seismometer" published in Marine Geophysical Researches 3 (1977), pp. 65-85, described the use of a "boat" floating in a liquid in a hemisphere to level seismic motion detectors in an OBS. The present invention is a novel device for leveling such detectors and, more importantly, can more easily and inexpensively be used than either gimbals or a "boat" with a clamping device such as a spring loaded plunger to preserve the orientation assumed by the leveled seismic detectors so that the angle of inclination assumed by the seismometer can subsequently be determined. RELATED APPLICATIONS U.S. application Ser. No. 163,757, filed June 27, 1980 "On-bottom Seismometer Electronic System", Bowden et al. describes an electronic system for timing the various functions performed by an on-bottom seismometer. U.S. application Ser. No. 144,092, filed Apr. 28, 1980, Prior, "Release Mechanism for On-Bottom Seismometer", discloses a release mechanism for such a seismometer. BRIEF SUMMARY OF THE INVENTION One or more of the seismic motion detectors carried in a seismometer especially designed to operate on the ocean floor is suspended at the end of a shaft protruding from a ball rotating in an annular seat to form a free moving pendulum. A spring loaded plunger, positioned above the ball, is restrained from contact with its surface by a pin which passes perpendicularly through the plunger and is connected to a linearly acting solenoid. After the seismometer has been positioned for operation, the solenoid is activated by appropriate means causing the pin to be pulled from the plunger which, under the force of its spring, extends to contact the surface of the ball locking it, the shaft and detector(s) in their positions. The detector(s), support means, solenoid and plunger are preferably mounted to the door of a water-tight instrument housing, a component of the seismometer. In the locked position, there is a rigid connection from the detector(s) through the support means to the door of the water-tight instrument housing which itself is rigidly mounted to the seismometer frame. The frame rests directly on the ocean floor when the seismometer is deployed. The water-tight instrument housing, which is preferably mounted on the lowest portion of the frame, will also tend to embed itself if the ocean floor is mud. This provides a good path for seismic waves traveling through the ocean floor to the chassis of the water-tight compartment. The seismic waves are, in turn, coupled through the rigid connection to the detector, thereby providing better recording of seismic refraction waves than has been provided with prior art devices. After recovery, the angle of inclination that the seismometer assumed with respect to the vertical at the time the ball was clamped can be determined by measuring the acute angle formed by the ball, shaft and detector(s) in their locked position and a surface known to be vertical when the seismometer is in the normal, up-right position it would assume on a flat, horizontal surface. The invention also comprises a method and apparatus for automatically leveling seismic motion detectors, when employed as the pendulum weight, for proper operation. OBJECTS OF THE INVENTION One object of the invention is to provide a simple and inexpensive method to determine the angle of inclination with respect to the vertical assumed by a recoverable device, such as a seismometer designed to operate on the ocean floor. Another object of the invention is to provide a simple and inexpensive apparatus for preserving the orientation assumed by such a device so that its angle of inclination with respect to the vertical can later be determined. Another object of the invention is to provide a mounting and clamp for a seismic motion detector which provide good acoustic coupling between the ocean bottom and the detector. Another object of the invention is to provide a simple and inexpensive apparatus for self-leveling the seismic motion detectors used in a seismometer especially designed to operate on the ocean floor. Another object of the invention is to provide an apparatus which both levels the seismic motion detectors carried in a seismometer especially designed to operate on the ocean floor and preserves the angle of inclination with respect to the vertical that the seismometer assumes during its operation. BRIEF DESCRIPTION OF THE DRAWINGS The previously stated features and objects of the present invention, as well as others, will appear more clearly upon reading the following description of the preferred embodiment of the invention depicted in the attached drawings, in which: FIG. 1 is a view of the seismometer deployed on the sea-bottom; FIG. 2 is a partially cross-sectioned view of the invention mounting a single geophone; and FIG. 3 is a partially cross-sectioned view taken along line 2--2 of FIG. 2. DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, the on-bottom seismometer is of the type described in the aforementioned applications. Briefly, the major components of th OBS depicted in the FIG. 1 include a frame 101, floats 102, an instrument compartment 103 which is sealed, and a ballast tube 104. Power supplies can be carried in the instrument compartment 103, one or more of the floats 102 or both. An identical ballast tube 104 is mounted as the "rear" side of the seismometer viewed in FIG. 1. When the seismometer is deployed on the ocean-bottom, the ballast tubes 104 normally are submerged into the mud or silt of the sea floor. The ballast tubes 104 are rigidly mounted to the frame and provide good seismic coupling between the frame of the seismometer and the ocean bottom. The instrument compartment 103 is preferably mounted at the bottom of the frame 101 to improve the seismometer's stability during descent, ascent and operation. Mounted in this way the instrument compartment 103 will also be embedded when the seismometer comes to rest on a soft, muddy surface thereby improving the seismic coupling between it and the ocean floor. In accordance with one aspect of this invention, the seismic detector is mounted on the inside of the door 12 of the instrument compartment 103. In accordance with the invention, a rigid connection is provided between the detector and the frame 101 of the seismometer to provide a good acoutic path between the sea bottom and the detector. An acoustic command unit 105 at the surface produces acoustic commands for the on-bottom seismometer. The commands are sensed by a hydrophone 106 mounted on the seismometer and wired to the instrument compartment 103. Such acoustic commands are used, for example, to trigger the clamping of the detector into position after deployment of the seismometer. Acoustic commands are also used to release the seismometer after recording is complete. A timer (not depicted) can alternatively be provided in the seismometer to trigger the clamping of the detector. FIG. 2 and FIG. 3 depict the preferred embodiment of the invention employed in a seismometer such as that depicted in in FIG. 1. A geophone 1, having a center of gravity 9 and a vertical operating axis (not depicted), is connected by a collar 3 or other suitable means to the end of a shaft 4 protruding from a spherical ball 5 having a center 10. Suitable means such as threading (depicted in FIGS. 1 and 2), glueing, etc. (not shown) are used to affix the collar 3 to the end of the shaft 4. The spherical ball 5 rests in an annular seat 6 provided in a mounting plate 7. To provide symmetrical freedom of motion to the geophone 1 and shaft 4, the annular plane formed within the circumference of the annular seat 6 should be horizontal when the seismometer in which the invention is installed is placed on a flat, horizontal surface. (Hereinafter this orientation of the seismometer shall be referred to as its "normal, up-right position".) The annular seat 6 is provided with a beveled face 6a for improved contact with the surface of the spherical ball 5. The geophone 1, shaft 4, and spherical ball 5, supported in this manner, form a simple pendulum. As a result of this arrangement, a line 8 passing through the center of gravity 9 of the geophone 1 and the center 10 of the spherical ball 5 will be vertically aligned when the geophone 1 is allowed to hang freely at the end of the shaft 4. Ideally, the center of gravity 9 should be located along a line passing through the center 10 of the spherical ball 5 and the central longitudinal axis of the shaft 4, as the line 8 is depicted to run in FIG. 2, to more easily measure the angle assumed by the geophone 1 and shaft 4 when locked into operating position while the seismometer is pitched over, but this alignment is not required to proper operation of the invention. Leads 2 carry the electrical signals between the geophone 1 and appropriate processing and recording equipment (not shown). Geophones and comparable seismic motion detectors are available from a number of commercial sources and are well-known. In the alternative to the vertical geophone depicted in the figures, a horizontal-type seismic motion detector or several seismic motion detectors can be mounted at the end of the shaft 4. The manner of mounting the detectors directly to the end of the shaft 4 or on or in a frame (not depicted) for mounting to the shaft 4 and the arrangement of the detectors are matters of personal preference. The construction, mounting and operation of such detectors are well known to those familiar with seismometer construction. It is only necessary that each detector be mounted with its operating axis parallel (if a "vertical" motion detector) or perpendicular (if a "horizontal" motion detector) to the line 8. Preferably, the detectors should also be mounted in such a way that the line 8 which will pass through the center of gravity of the detector or assembly of detectors coincides with the line passing through the central longitudinal axis of the shaft 4, again for ease of measuring the angle of inclination. Suspended in this fashion, each detector will be automatically aligned with respect to the vertical for proper operation by the pendulum action of the invention. A stop ring 11 is preferably provided in the mounting plate 7 to prevent damage to the seat 6 which might occur if it were allowed to be struck by the side wall of the shaft 4, during handling or placement of the seismometer mounting the invention. Preferably the centers of the open planar areas formed within the circumferences of the annular seat 6 and stop ring 11 should lie along the line 8 when the seismometer is in its normal, up-right position to assure symmetrical freedom of motion of the geophone 1 and shaft 4 perpendicular to the vertical. The positions of geophone 1 at its outer limits of travel with the stop ring 11 installed are depicted in phantom in both FIG. 2 and FIG. 3. Although a total arc of less than 90° is illustrated, the inner diameter of annular seat 6 could be increased to a small fraction of an inch less than the diameter of the spherical ball 5 and that of the stop ring 11 also increased to allow a total arc of movement greater than 90° but less than 180°. If so constructed this would allow the invention to operate properly until the seismometer is pitched over at almost 90° from its normal, up-right position. The mounting plate 7 is affixed by suitable means inside the instrument compartment 103 to the planar surface of its door 12. The door 12, which pivots around a vertical axis, is an ideal surface on which to mount the detector as it offers easy access to "cock" a plunger 30 for operation, as will be later described, and simplifies measuring the angle assumed by the geophone 1 and shaft 4 when clamped. The mounting plate 7 is designed to prevent the geophone 1 from striking other surfaces including the inner surface of the door 12. (See FIG. 3). If the invention is used to level one or more seismic motion detectors, the seismometer and enclosure are constructed of suitable materials and in such a way that seismic vibrations are transmitted without significant dampening or filtering from the ocean floor on which the seismometer lies to the surface of the door 12 supporting the invention. Similarly, the means by which the mounting plate 7 is attached to the door 12 and the material from which the mounting plate 7, annular seat 6, spherical ball 5, shaft 4, and collar 3 are constructed are suitable to transmit seismic vibrations without dampening or filtering to the geophone 1. Those knowledgeable with seismometer construction will be familiar with the variety of materials and techniques available to them for constructing the invention. As depicted in FIGS. 2 and 3, the mounting plate 7 is adapted to receive a plunger shaft 30b which is the central body of the plunger 30. A head 31 is mounted by suitable means, such as a clevis 32, to the end of the plunger shaft 30b closest to the spherical ball 5. The plunger 30 should be positioned on the mounting plate 7 in such a way that when the plunger 30 is extended, its head 31 comes into sufficient contact with the surface of the spherical ball 5 so as to lock the spherical ball 5, shaft 4 and geophone 1 in their assumed orientation. Preferably, the plunger 30 should also be positioned so that a line extending through the central longitudinal axis of the plunger shaft 30b also passes through the center 10 of the spherical ball 5 and the center of the open planar area formed within the circumference of the annular seat 6. This will reduce the likelihood of the plunger 30 imparting a torsional force to the spherical ball 5 when striking it, disturbing the position of the shaft 4 and cylinder 1. The head 31 should be constructed of synthetic rubber of other material suitable to cushion the impact of the plunger 30 when it strikes the surface of the spherical ball 5 so as not to disturb its position or that of the geophone 1 and to grip the surface of the spherical ball 5 so that it does not subsequently rotate. Although not required for proper operation of the invention, the end of the plunger 30 opposite the head 31 is preferably shaped into a handle 30a allowing that end of the plunger to be more easily gripped. A coil spring 33 is positioned around the plunger shaft 30b. Suitable surfaces such as an overhand 31a of the head 31 and a surface 7a of the mounting plate 7 are provided as a means for compressing the coil spring 33. The coil spring 33 must be selected so as to remain in a sufficiently compressed state when the plunger 30 is fully extended to assure that sufficient forces are imparted by the head 31 to the spherical ball 5 to prevent its further motion or rotation and to further assure that the spherical ball 5 is firmly pressed against the annular seat 6 so as to provide an adequate path for seismic vibrations from the annular seat 6 to the geophone 1. A first bore 13 is provided in the mounting plate 7 to allow the passage of a pin 15. A second bore 14 is provided in the plunger shaft 30b to receive the pin 15. The purpose of the pin 15 is to restrain the plunger 30 away from the surface of the spherical ball 5 and the first bore 13 and second bore 14 must be suitably located to accomplish this when the pin 15 is positioned within them. A solenoid 16 is provided as a means for removing the pin 15. The solenoid 16 is mounted to the mounting plate 7 or some other suitable surface by screws 16b or suitable means. A power source (not depicted) supplies electric current through a set of solenoid leads 16a to activate the solenoid 16. The solenoid 16 in FIG. 2 is depicted as having a linearly acting shaft 17 connected by a clevis 18 or other suitable means to an end of the pin 15. This mechanical linkage enables the pin 15 to be removed from the bore 14 in the plunger shaft 30b by the solenoid 16 when the latter is activated. Solenoids equipped with linearly acting shafts are available from a variety of commercial sources and their operation is well-known. Alternatively, any other device which can be activated to produce a linear stroke action adequate to remove the pin 15 from the plunger shaft 30b could be used in place of the solenoid 16 and linearly acting shaft 17. In the preferred embodiment of the invention depicted in FIG. 2, a second coil spring 19 is positioned around the linearly acting shaft 17. A second plate 20, attached by screws 20a or other suitable means to the mounting plate 7 is provided as a surface against which the second coil spring 19 may be compressed. A face of the solenoid 16 may prove to be adequate for this purpose. The clevis 18 at the end of the pin 15 provides a suitable second surface against which the second coil spring 19 may be compressed. The purpose of the second coil spring 19 is to push the pin 15 to the left, as viewed in FIG. 2, to engage the second bore 14 when the first bore 13 and second bore 14 are aligned. The operation of the invention is as follows. Before deploying the seismometer carrying the invention, the plunger 30 is cocked for operation by lifting it by its handle 30a and rotating it until the first bore 13 and second bore 14 align. At that point the second coil spring 19 in compression, forces the pin 15 to the left (as viewed in FIG. 2) causing the pin 15 to pass into the second bore 14 and engage the plunger shaft 30b restraining the head 31 from contacting the surface of the spherical ball 5. The seismometer carrying the invention is then deployed for operation as shown in FIG. 1. Once the unit is deployed, the line 8 passing through the center of gravity 9 of the geophone 1 (which is free to swing at the end of the shaft 4) and the center 10 of the spherical ball 5 is immediately and automatically aligned with respect to the vertical by the pendulum action of the invention. The geophone 1, which has been mounted with its vertical operating axis parallel to the line 8, is now positioned for proper operation. After the seismometer has been given an adequate amount of time to stabilize, an electric current is introduced from a power source (not shown) through the solenoid leads 16a activating the solenoid 16 causing the linearly acting shaft 17 to be moved to the right (as viewed in FIG. 2) withdrawing the pin 15 from the second bore 14. The coil spring 33 in compression forces the head 31 of the plunger 30 into contact with the surface of the spherical ball 5 locking it, the shaft 4 and the geophone 1 in their assumed positions. The acute angle formed by the line 8 when the geophone 1 is in its clamped position and in the position it assumes when hanging freely in the seismometer in the latter's normal, up-right position is the angle of inclination assumed by the seismometer. If the line 8 passes through the central longitudinal axis of the shaft 4, the angle of inclination can be determined by measuring the acute angle between the longitudinal side wall of the shaft and a surface, such as the door 12 or one of the walls of the instrument housing 103, known to be vertical when the seismometer is in its normal, up-right position. Not included as part of the invention and heretofore omitted from this description has been the means by which the current to activate the solenoid 16 is controlled. Several methods, such as internal timers and acoustic signals can be used with on-bottom seismometers to activate switches. For example, a system which can be used for controlling the supply of electrical power to the solenoid 16 is described in the related U.S. application Ser. No. 163,757, filed June 27, 1980, "On-Bottom Seismometer Electronic System", Bowden et al. It is expected the user will select a method for activating the solenoid 16 or other device provided to remove the pin 15 from the plunger 30 which is most compatible with the other features of his seismometer. Although the principles of the present invention have been described above in relation to a preferred embodiment, it must be understood that the description is only made by way of example and does not limit the scope of the invention.

A geophone is hung from a ball bearing in a pendular fashion so that it is free to swing in any direction. Because it is weighted, it will assume the correct positioning for operation. A clamp, carried with the pendular geophone in a seismometer designed for use on the ocean floor, fixes the geophone in a rigid position when a solenoid is actuated. After the seismometer is deployed on the sea bottom, it is desired to clamp the geophone into its assumed position. The solenoid is fired upon command causing the ball to be clamped. When the seismometer is recovered the angle of inclination with respect to the vertical it assumed at the time when the geophone was clamped can be determined by measuring the angle formed by the clamped geophone and a surface known to be vertical when the seismometer rests on a flat, horizontal surface.

big_patent

BACKGROUND OF THE INVENTION Various types of humidity sensing elements, or so-called humidity elements, have been used as the tranducers of hygrometers for quantitatively sensing the water vapor content of gaseous atmospheres. Paper, or horsehair, sensing elements which respond by relatively slow changes in length dimension to changes in atmospheric moisture content have been used for many years. More sophisticated humidity sensors such as the Dunmore cell have used layers of hygroscopic chemicals such as lithium chloride as variable resistors between the electrodes of the sensors, the electrical resistance of the lithium chloride being a function of the amount of moisture absorbed from the surrounding atmosphere and measurable by electrical instrumentation. A moisture sensing element disclosed in U.S. Pat. No. 3,748,625 has a pair of electrodes spaced apart by a crystal lattice which permits molecules of the atmosphere being monitored to randomly drift in and out of the crystal interstices due to vapor pressure changes, and the volumetric resistance of the sensor changes as a function of the percent of water vapor present in the molecules of atmosphere within the interstitial spaces. The paper or horsehair sensing elements are slow to react to moisture changes, and their reactions must be mechanically measured with the attendant problems of stickslip friction, damage possibilities, adjustment requirements, and mechanical wear problems, and do not provide the accuracy of humidity measurement which is desired in many applications. The Dunmore cell type sensors are delicate to the extent that they can be decalibrated by a fingerprint, and in that their hygroscopic nature gathers moisture from the atmosphere which may create a high humidity zone around the sensor with resultant inaccuracies in measurements. The sensor of U.S. Pat. No. 3,748,625 requires long and involved processes and results in a sensor which would appear to require special housing for physical protection. In contrast, the present invention provides a relative humidity sensing element that may be energized or excited by low voltage microscopic currents from solid state electronic instrumentation, does not depend on mechanical movements, is physically sturdy and requires no special physical protection, is not affected by fingerprints or reasonably dirty environments, is non-hygroscopic so that moisture only permeates the element and is not attracted by it nor collected in it, has a response time on the order of one second, and is manufactured by a method comprised by a novel combination of familiar and non-exotic manufacturing methods. SUMMARY OF THE INVENTION The humidity sensing element for gaseous fluids of the present invention comprises a first electron conductive electrode, a porous coating of dielectric thereon, minute particles of electron conductive material deposited in the interstices of the porosity of the dielectric, a second electron conductive electrode pervious to moisture vapor and disposed on the dielectric coating on the opposite side thereof from the first electrode, an ion-forming material in the dielectric commonly contacting the particles and the second electrode and reducing the porosity of the dielectric, the impedance between the electrodes varying generally linearly with relation to the relative humidity of the surrounding gaseous atmosphere in a suitable range of interest when excited by a suitable alternating current voltage. Briefly described, the humidity element of the present invention has the first electrode formed from commercially pure anodizable metal, an anodized layer thereof forms the dielectric coating, the minute particles deposited therein are metal and the ion-forming material contacting them reduces the porosity of the dielectric, the impedance between the electrodes is a capacitance-resistance combination, and the second electrode is formed by vacuum deposition of metal from a plated hot filament onto the anodized layer. Preferably the humidity sensing element of the present invention has had the dielectric beneath the second electrode formed by oxalic acid anodizing on a portion of the sensing element having an initial surface finish roughness of about 8 micro inches root means square, minute particles of nickel have been deposited in the porosity of the dielectric, the anodized dielectric has been hydrolized and sealed to contact the nickel particles with ion-forming material, and the second electrode is formed by a deposit of nickel in quantity equivalent to an amount calculated for deposition of a layer approximately 100 Angstrom units thick on a smooth non-porous surface. In the preferred embodiment, the humidity element of this invention has the first electrode formed from 99.4% pure aluminum which is anodized to a thickness in the range of about 0.02 to 0.08 millimeters, atom-sized nickel particles are deposited in the interstices of the anodized dielectric while it is dry and unsealed by vacuum deposition from a hot nickel-plated filament in a quantity equivalent to an amount calculated to deposit on a smooth non-porous surface a layer between 5 and 10 Angstrom units thick, and the element is suitable for excitating for sensing by an alternating current sine wave voltage in the order of 10 Hertz for optimizing the temperature effects on the linearity of the decreasing impedance with increasing relative humidity relationship of the element. It is preferred to make electrical contact with the second electrode by a coating of electrically conductive material covering a portion of the second electrode and also covering an otherwise exposed portion of an insulating and cushioning element adhered to the sensing element so that a pressure contact electrical connection to the conductive material and thereby to the second electrode may be made by pressure on the cushioning element without shorting the second electrode to the first electrode by inadvertently crushing the dielectric between them. Briefly described, the method of manufacturing the humidity sensing element of the present invention comprises the steps of coating at least a portion of a first electron conductive electrode with a porous coating of dielectric, depositing minute particles of electron conductive material in the interstices of the porosity of the dielectric, commonly contacting the particles in the interstices by means of an ion-forming material, and forming a second electron conductive electrode contacting the ion-forming material and pervious to moisture vapor and disposed on the dielectric coating on the opposite side thereof from the first electrode whereby the impedance between the electrodes varies generally linearly with relation to the relative humidity of the surrounding gaseous atmosphere in a suitable range of interest when excited by a suitable alternating current voltage. Preferably, the method of manufacturing for the present humidity element includes forming the first electrode from commercially pure aluminum and anodizing the aluminum to form the dielectric coating, vacuum depositing atomic particles of nickel from a hot filament into the interstices of the porosity of the dielectric in a quantity equivalent to an amount calculated to deposit a layer of thickness between 5 and 10 Angstrom units on a smooth non-porous surface, contacting the particles in the interstices by hydrolizing and sealing the anodized coating, and vacuum depositing nickel onto the sealed anodized coating to form the second electrode. The preferred method of manufacturing the present humidity element includes oxalic acid anodizing the aluminum to a thickness of about 0.02 to 0.08 millimeters, and depositing nickel for the second electrode in a quantity equivalent to an amount calculated to deposit a layer about 100 Angstrom units thick on a smooth non-porous surface. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an axial view of a typical cylindrical sensing element according to the present invention; FIG. 2 is a longitudinal cross sectional view taken along the line 2--2 of FIG. 1 and showing in phantom typical mounting and electrical connection arrangements for the sensing element; and FIG. 3 is an enlarged schematic cross sectional view taken generally within the circular area designated 3--3 in FIG. 2. DESCRIPTION OF THE PREFERRED EMBODIMENT The humidity element, or humidity sensing element, of the preferred embodiment of the present invention is suitable for excitation by a ten Hertz sine wave alternating current electrical voltage impressed across its electrodes by a solid state electronic measurement circuit and consists essentially of a tubular aluminum first electrode member whose bore has been anodized, the anodized layer impregnated in its porosity with nickel particles by vacuum deposition, the anodized layer sealed, and the sealed anodized layer overlaid with a porous vacuum deposition of nickel to form a second electrode. The sensing element 10 as shown in FIGS. 1 and 2 is typically a small, hollow cylinder of commercially pure (99.4%) aluminum, such as Alloy 1100, having an outer flange 12 for mounting purposes at one end. The hollow bore 14 of the sensing element 10 is typically machined to a very fine finish and then roller burnished to a very smooth, about 8 micro inch, surface finish. A typical element 10 has a bore of about 15 millimeter diameter, 32 millimeter length, and a wall thickness of about 15 millimeters. The entire element 10 is initially anodized by conventional methods in a 3 percent solution by weight of oxalic acid in distilled water at ambient temperature at a current density of 12 amperes per square foot for 60 to 70 minutes to achieve an anodized coating or layer of aluminum oxide or alumina (Al 2 O 3 ) of about 0.02 to 0.08 millimeters thickness. This anodized layer is then thoroughly rinsed to remove the acid and is then dried at about 38 degrees C. for 24 hours. The anodized layer has an open pore structure probably similar to a miniaturized layer of rocks, probably formed by amorphous agglomerations of aluminum oxide molecules which grow bouldered-up from the essentially pure aluminum base metal during the anodizing process, and it is nearly impervious at the metal base and ever more porous toward the surface of the layer. In the preferred embodiment disclosed here, the hollow bore 14 of the sensing element 10 forms the moisture sensing portion of the element, and it is therefore suitably treated to deposit minute particles 16 of a suitable metal such as nickel into the interstices 19 (as schematically represented in FIG. 3) of the porosity of the anodized layer 18 inside the bore 14. In the preferred method of manufacture of the present sensor, the anodized layer 18 within the hollow bore 14, having been rinsed and dried, is exposed to vacuum deposition bombardment by atoms of nickel by heating a solid tungsten wire centered axially within the bore 14, the tungsten wire having been previously electroplated with a quantity of nickel equivalent to an amount calculated at 95% plating efficiency to be sufficient to form a layer of nickel 5 to 10 Angstrom units thick at 95% deposition efficiency if the surface of the bore 14 were smooth and solid. However, since the surface of the bore 14 is microscopically highly porous, the atoms of nickel will be randomly deposited within the interstices of the porosity of the anodized layer 18, in decreasing quantities down into the layer 18 toward the base metal, and the atoms of nickel will adhere to the interstitial surfaces of the anodized layer 18 as is typical of vacuum deposition. The preferred method of vacuum deposition is at a calculated tungsten wire temperature of 2600° F. for 15 seconds in a 10 -5 to 10 -6 torr vacuum. Following deposition of the nickel particles 16 on the unsealed anodized layer 18, the sensing element or sensor 10 is placed in a boiling water bath to hydrolize and seal the anodized layer 18 as is common in anodizing practice. Thereafter, the sensor 10 should be thoroughly dried at about 150° F. before the next step. Sealing partially converts the as-anodized alumina of the anodized layer 18 to an aluminum monohydrate, and this reduces the porosity of the anodized layer 18 somewhat, as well as leaving the nickel particles 16 in contact with the ion-forming aluminum monohydrate probably containing residual traces of oxalic acid and layer 18 vapor pervious. It is next desirable to form a thin, water vapor pervious electrode over the nickel-impregnated sealed anodized layer 18 which lies within the bore 14, and this is again preferably accomplished by vacuum deposition of nickel atoms on the surface of the bore from a nickel-plated axially centered tungsten wire for 15 seconds at a temperature of 2600° F. in a 10 -5 to 10 -6 torr vacuum. The amount of nickel in this deposition is calculated at 95% plating efficiency to be equivalent to that amount which would form a layer 100 Angstrom units thick at 95% deposition efficiency if the surface of the bore 14 were smooth and solid. However, due to the porosity of the sealed anodized layer 18 and the thinness of the nickel deposition, a probably lacy deposit of nickel is formed which is pervious to atmospheric molecules while being electrically conductive to form a second electrode 20 separated from the first electrode formed by the aluminum body 22 of the sensor 10 by the doped dielectric layer 24 formed by the nickel impregnated sealed portion of the anodized layer 18. As shown in FIGS. 1 and 2, the sensor 10 may be suitably mounted in a mounting bracket 25 suitably provided with a bore 28 and a counterbore 30 for receiving the cylindrical portion and the flange 12 of the sensor 10, and a clamping ring 32 of non-conductive or insulating material equipped with suitable screws for engagement with threaded holes in the bracket 26 for firmly mounting the sensor 10. To facilitate a suitable pressure electrical contact with the second electrode 20 without inadvertent crushing of the doped dielectric layer 24 that could effectively short circuit the two electrodes, a thin plastic insulating ring 34 is adhesively fastened to the flanged outer end of the sensor 10, the ring 34 having the same inside diameter as the sensor 10 and an outside diameter slightly less than that of the flange 12, and a layer 35 of electrically conductive material, such as conductive paint or metallic ink, is applied as shown in FIG. 2 to cover the second electrode 20 for a short distance within the bore 14 and to extend unbroken over the inside diameter of the plastic ring 34 and over its exposed flat surface. A suitable metal ring 36 of approximately the same diameter dimensions as the ring 34 and having an electrical conductor 37 connected thereto, may then be clamped over the conductive layer 35 by the insulating clamping ring 32. Electrical connection to the first electrode formed by the aluminum body 22 is suitably made by machining the anodized layer 18 from the underside 38 of the flange 12 for pressure contact with the mounting bracket 26 which is suitably at ground potential for eliminating stray current effects on the sensor 10. Thus, the sensor 10 is self-contained and forms its own protection for the humidity-sensitive portion in its bore, while the surrounding atmosphere may circulate freely through the bore (which is normally mounted vertically) for free exchange of atmospheric molecules with the dielectric layer 24. The exact means by which the sensor of this invention functions to have an impedance which decreases generally linearly proportionally to the relative humidity of the atmosphere to which it is exposed must be a subject for theorizing. However, the invention of the present sensor was based on the theory that while the capacitance of a porous dielectric between electrodes will increase linearly with the number of water vapor molecules present in the dielectric, the resistance of many materials increases as the temperature increases, so that in theory, a suitable combination of capacitance and resistance in a humidity sensing element should result in a humidity element which responds essentially linearly proportionally to the relative humidity of the atmosphere to which it is exposed. This may be explained by the facts that relative humidity is essentially defined as the ratio of the specific quantity of water vapor in a given volume of air at a given temperature, compared to the maximum specific quantity of water vapor which the same volume of air could hold in vapor form at that temperature, and that a rise in the temperature of air containing a specific quantitiy of moisture vapor causes the relative humidity to go down, and vice versa, and that an increase in the specific amount of moisture vapor in a volume of air held at constant temperature causes the relative humidity to rise, and vice versa. Thus, in theory, the ideal humidity sensing element should combine capacitance and electrical resistance in a suitable manner such that its total impedance will vary essentially linearly proportionally with the relative humidity; that is, when the temperature rises while the moisture vapor molecules in the atmosphere remain constant, the resistance should rise, while the capacitance remains constant, resulting in an increasing total impedance with rising temperature, and vice versa. Also, when the atmospheric temperature remains constant, and the number of water vapor molecules therein is increased, then the capacitance of the sensor should increase, and its impedance thereby decrease, while its resistivity remains constant and its total impedance thereby decreases, and vice versa. Such a combination results in a sensor whose impedance varies inversely proportionally to the relative humidity of the atmosphere, and when such a sensor is connected in series with a resistance and excited by a suitable alternating current voltage, the voltage drop across the series resistor will vary directly as the relative humidity of the atmosphere. In theory, again, water vapor molecules within the dielectric of a capacitance become polarized, but are non-conductive and only serve to increase the capacitance of the dielectric. In the present sensing element, water vapor molecules in the presence of the ion-forming aluminum monohydrate in contact with the nickel particles in the anodized layer 18 will form conductive ionization paths between the nickel particles and lower the resistance in the path between the electrodes, yet and resistance paths are affected by temperature increases to increase their resistance. The end result of the preferred embodiment disclosed herein is that the combination of resistance, which is responsive both to water molecules and to temperature changes, combined with the capacitance, which is essentially responsive to the presence of water vapor molecules, forms a sensor whose impedance is essentially linearly inversely proportional to the relative humidity of the atmosphere to which it is exposed, and the impedance changes almost instantly in response to relative humidity changes (response time in the order of 1 second) due to the thin and molecularly porous dielectric and second electrode. While it has not been determined what specific conditions would give a perfectly linear relation between sensor impedance and relative humidity, it has been determined that the relation is sufficiently linear in the present sensor for effective performance in a suitable range of temperatures and humidities as normally must be controlled in typical textile mills, which may typically require temperatures between 75° F. and 85° F. and relative humidities between 40% and 85%. It has been found that the present sensor varies notably from a linear response when excited by 60 Hertz AC voltage, but that linearity is improved when it is excited with 20 Hertz AC voltage, and that it is improved still further when excited by 10 Hertz AC voltage, to the extent that 10 Hertz excitation provides substantial linearity for the commercial humidity controls for which the present sensor is designed. Among other limiting conditions to the present sensor, it has been found that excessive impurities in the aluminum will result in an anodized layer 18 containing unanodized alloying particles which will effectively short circuit between the two electrodes, but the commercially available electrical conductor Alloy 1100 functions suitably. Likewise, if the calculated thickness of nickel deposited in the porosity of the anodized layer 18 exceeds 10 Angstrom units, the two electrodes again tend to become shorted out, while a calculated thickness of less than 5 Angstrom units fails to supply the resistive component of impedance between the two electrodes which is desired. Also, the anodized layer 18 achieved in the bore 14 after it has been fine machined and roller burnished to a surface finish approximating 8 micro inches by an anodizing bath consisting of a 3% solution by weight of oxalic acid in distilled water at room temperature for 60 to 70 minutes at a current density reaching 12 amperes per square foot has been found satisfactory, and is believed to lie in the range of 0.02 to 0.08 millimeters thickness. Hydrolizing and sealing the anodized layer 18 decreases the porosity of the anodized layer such that the deposited second electrode 20 on the anodized layer 18 does not get down into the porosity of the anodization enought to short out the nickel atoms already deposited therein. It has been found that sulfuric acid or nitric acid anodized layers, when sealed, apparently contain so much residual ion-forming material that they effectively short circuit the two electrodes and are therefore unsatisfactory, and oxalic acid, which is an organic acid, has been found to give suitable results. Similarly, when the second electrode 20 was deposited with a calculated thickness of 25 Angstrom units, it was found to be non-conductive, 50 Angstrom units was conductive, but 100 Angstrom units appears to be best for conductance and porosity, while 200 Angstrom units is not sufficiently porous and permeable. It is recognized that there may be variables in the dimensions, materials, and processes for manufacturing humidity elements according to the concepts of the present invention, and this preferred embodiment presents a workable element and method of manufacture therefor, which is disclosed in full detail and illustrated in the drawings for disclosure purposes only, but it is not intended to limit the scope of the present invention, which is to be determined by the scope of the appended claims.

A doped capacitance humidity sensing element and method of manufacture thereof is provided. The element has a response time in the order of one second and has one electrode formed by an anodizable metal, an anodized layer thereon, conductive, metal atoms deposited in non-short-circuiting mutual relation in the interstices of the anodized layer, the anodized coating layer sealed to contact the particles with an ion-forming material and reduce the porosity of the coating, and a second electrode formed by a moisture-vapor-pervious, electron-conductive layer of metal deposited on the sealed anodized coating on the opposite side from the first electrode, the anodized coating layer being generally pervious to the surrounding gaseous atmosphere and the moisture vapor thereof and the capacitance element presenting an impedance to low frequency sine wave electrical excitation varying inversely and generally proportionally to the relative humidity of the surrounding gaseous atmosphere.

big_patent

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This non-provisional patent application claims priority under 35 U.S.C. §119(a) from Patent Application No. 200810142381.1 filed in The People's Republic of China on Aug. 15, 2008. FIELD OF THE INVENTION [0002] This invention relates to a motor assembly, and in particular, to a motor assembly having a force transmission structure. BACKGROUND OF THE INVENTION [0003] Usually, a window lift system for a vehicle window comprises a driving motor, a lift device for moving up or down the glass of the window, and a force transmission structure for transmitting rotation of the output shaft of the motor to the lift device. The transmission structure comprises a drive plate and a shaft coupled to the drive plate. The drive plate is connected to the output shaft of the motor via a gear train. The shaft is connected to the lift device via a pinion attached to an end of the shaft and meshed with a gear of the lift device. In operation, the motor drives the drive plate to rotate. The drive plate drivingly rotates the shaft to thereby cause the lift device to move the glass of the window up or down. [0004] Conventionally, the shaft is coupled to the drive plate via a cylindrical coupling end with two flat surfaces at opposite sides thereof fittingly received in a waist-shaped hole of the drive plate. Two opposite flat interfaces are formed between the coupling end of the shaft and the hole of the drive plate. In operation, two reverse forces are exerted on the two flat surfaces of the coupling end of the shaft, which will generate impact on the shaft and the drive plate to thereby generate vibration and noise. [0005] As such, there is a desire for an improved transition structure which can solve the above-mentioned problems. SUMMARY OF THE INVENTION [0006] Accordingly, in one aspect thereof, the present invention provides a force transmission structure comprising: a drive plate having a mounting hole and a shaft fitted to the mounting hole for rotation with the drive plate, wherein the mounting hole has at least three sections interconnected with one another at a common area, the shaft has a toothed portion with at least three teeth fittingly received in the sections of the mounting hole such that the shaft is fixed to rotate with the drive plate. [0007] Preferably, the drive plate comprises a body and a coupling formed at the center of the body, the coupling is deeper than the body in the axial direction of the body, the mounting hole being formed in the coupling. [0008] Preferably, the coupling has buffer holes respectively located between adjacent sections. [0009] Preferably, the drive plate has a plurality of protrusions formed on a first side of the body and configured to engage with a driving member such that the driving member is able to drive the drive plate, the shaft further comprises a pinion configured to drive a driven member. [0010] Preferably, the drive plate further comprises a plurality of ribs formed at an opposite second side of the body. [0011] Preferably, the mounting hole and the toothed portion are Y-shaped. [0012] Preferably, the drive plate is made of a plastics material. [0013] According to a second aspect, the present invention provides a motor assembly comprising: a motor; a force transmission structure comprising a drive plate and a shaft; and a gear train connecting the motor to the drive plate for driving the drive plate; wherein the drive plate has a mounting hole with at least three sections interconnected with one another at a common area, the shaft has a toothed portion with at least three teeth fittingly received in the sections of the mounting hole of the drive plate such that the shaft is fixed to rotate with the drive plate. [0014] Preferably, the gear train comprises a worm driven by the motor, a worm gear meshed with the worm, and a damper attached to and rotatable with the worm gear, the drive plate being driven by the worm gear through the damper. [0015] Preferably, the worm comprises an inner ring, an outer ring, and a plurality of ribs extending from the inner ring to the outer ring, the damper being received in a space formed between the inner ring and the outer ring and having a plurality of first slots for fittingly receiving the ribs respectively. [0016] Preferably, the drive plate comprises a body and a plurality of protrusions formed at one side of the body, and the damper has a plurality of second slots engaging with the protrusions of the drive plate. [0017] Preferably, the protrusions are V-shaped, the width of the protrusions increasing gradually from the inner most portion towards the outer most portion in a radial direction of the body. [0018] Preferably, the drive plate further comprises a coupling formed at the center of the body, the coupling having a greater axial depth than the body, and the mounting hole being formed in the coupling. [0019] Preferably, the coupling has buffer holes respectively located between adjacent sections of the mounting hole. [0020] Preferably, the mounting hole and the toothed portion of the shaft are Y-shaped. [0021] Preferably, the drive plate is made of a plastics material, and the damper is made of rubber. [0022] Preferably, the shaft further comprises a pinion for driving a gear of a window lift system. [0023] Preferably, the shaft is held captive within the mounting hole by a circlip located within a groove in the distal end of the toothed portion. BRIEF DESCRIPTION OF THE DRAWINGS [0024] A preferred embodiment of the invention will now be described, by way of example only, with reference to figures of the accompanying drawings. In the figures, identical structures, elements or parts that appear in more than one figure are generally labelled with a same reference numeral in all the figures in which they appear. Dimensions of components and features shown in the figures are generally chosen for convenience and clarity of presentation and are not necessarily shown to scale. The figures are listed below. [0025] FIG. 1 is a partial cross sectional view of a motor assembly in accordance with an embodiment of the present invention; [0026] FIG. 2 is an exploded view of the motor assembly of FIG. 1 ; [0027] FIG. 3 is a plan view of a drive plate of the motor assembly of FIG. 1 ; [0028] FIG. 4 is an isometric view of a shaft of the motor assembly of FIG. 1 ; [0029] FIG. 5 is an assembled view of the drive plate of FIG. 3 and the shaft of FIG. 4 ; and [0030] FIGS. 6A and 6B are schematic diagrams showing forces acting between the drive plate and the shaft. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0031] FIG. 1 shows a partial cross sectional view of a motor assembly in accordance with the preferred embodiment of the present invention. The motor assembly comprises a motor 10 and a gear train driven by the motor 10 . The gear train includes a force transmission structure. The gear train is contained in a gear housing 14 and a capstan 16 , which is a part of a window lift mechanism, is visible at the back. The capstan is driven through gears (not shown) by the motor assembly. [0032] FIG. 2 is an exploded view of the gear train, with the gear housing removed, to show the various components. The gear train comprises a worm 20 fitted to a motor shaft 12 driven by the motor 10 , a worm gear 30 which meshes with the worm 20 , a damper 40 , a drive plate 50 and a shaft 60 . The force transmission structure comprises the drive plate 50 and the shaft 60 . The worm 20 may be press fitted to the motor shaft 12 . Alternatively, the worm 20 may be formed integral with the motor shaft 12 . The worm gear 30 comprises an inner ring 31 , an outer ring 33 , and a plurality of ribs 32 radially extending from the inner ring to the outer ring. Teeth are formed at the outer circumferential surface of the outer ring 33 , for meshing with the worm 20 . The damper 40 is made of rubber material, has a through opening at the center thereof and has a plurality of first slots 41 and second slots 42 extending radially thereof. The slots 41 , 42 are arranged alternately in the circumferential direction. [0033] Referring also to FIG. 3 , the drive plate 50 , which may be made of an engineering plastics material, comprises a round body 52 , a coupling 54 formed at the center of the body 52 , a plurality of V-shaped protrusions 56 formed on one side of the body 52 , and a plurality of ribs 58 formed on the opposite side of the body 52 . The coupling 54 extends beyond the body 52 in opposite axial directions of the body 52 and therefore the coupling 54 has a greater depth or thickness than the body 52 . The coupling 54 has a Y-shaped mounting hole 55 at the center thereof, that is, the mounting hole 55 comprises three sections interconnected at the center thereof. Preferably, the coupling 54 further has a plurality of buffer holes 57 . In the embodiment, the buffer holes 57 are three blind holes which do not pass completely through the coupling 54 axially, and are evenly distributed in the circumferential direction, each one being located between adjacent sections of the Y-shaped hole 55 . In this embodiment, the protrusions 56 comprise three protrusions 56 evenly distributed in the circumferential direction, the width of the protrusions increasing gradually from the inner most portion towards the outer most portion in the radial direction of the body 52 . The central line of each protrusion 56 extends radially through the center of the body 52 . The protrusions 56 are shaped and sized to fit the second slots 42 of the damper 40 . [0034] Referring to FIG. 4 , the shaft 60 , which is the output shaft of the gearbox in the preferred embodiment, comprises a round portion 61 , a toothed portion 62 formed at one end of the round portion, and a pinion 64 formed at the other end of the round portion. The toothed portion 62 has a Y-shaped cross section and comprises three teeth evenly distributed in a circumferential direction of the shaft 60 . The shape and size of the teeth of the toothed portion 62 conform to that of the mounting hole 55 of the drive plate 50 . Preferably, the shaft 60 is made of low alloy steel. Alternatively, the shaft 60 may be made of other metal material. The pinion 64 is configured to couple with a gear, such as a gear train of a lift mechanism of a window lift system. [0035] Referring to FIGS. 1 and 5 , when assembled, the damper 40 is located in a spaced formed between the inner ring 31 and outer ring 33 of the worm 30 and the ribs 32 of the worm 30 are received in the first slots 41 of the damper 40 . The protrusions 56 of the drive plate 50 are respectively, interferentially and fittingly received in the second slots 42 of the damper 40 . Thus, the drive plate 50 is rotated by the damper 40 and the worm gear 30 when the worm 20 drives the worm gear 30 . [0036] The Y-shaped toothed portion 62 of the shaft 60 extends through the inner ring 31 of the worm gear 30 to be fitted in the Y-shaped mounting hole 55 of the drive plate 50 . The free end of the toothed portion 62 of the shaft 60 extends beyond the coupling 54 . A circlip 70 is fitted in a slot 66 formed at the free end of the toothed portion 62 to prevent the toothed portion 62 escaping from the mounting hole 55 . In operation, the motor 10 rotates the motor shaft 12 , which rotates the worm 20 , which drives the worm gear 30 , which rotates the drive plate 50 via the damper 40 , and thus rotates the shaft 60 . The drive plate 50 drives the shaft 60 to rotate by the Y-shaped mounting hole 55 of the drive plate mating with the Y-shaped toothed portion 62 of the shaft 60 . Consequently, the pinion 64 drives the capstan 16 via one or more gears (not shown) of the window lift system to thereby raise up or lower down the glass of the window. The window lift system may have a wire which is wound about the capstan to raise or lower the glass [0037] Referring to FIGS. 6A and 6B , in the embodiment of the present invention, when the shaft 60 is rotated by the drive plate 50 , three equal forces A, B, C from the coupling 54 are exerted on the three teeth of the toothed portion 62 of the shaft 60 respectively. These three forces A, B, C exerting on the three teeth of the toothed portion 62 constitute a triangle as shown in FIG. 6B . Therefore, the shaft 60 is rotated stably to thereby move up and/or down the glass of the window lift system quietly. Furthermore, the contact area between the teeth of the shaft 60 and the coupling 54 of the drive plate 50 is greater than that in the traditional design, which results in the connection between coupler and the shaft being able to withstand a greater torque. Moreover, the drive plate 50 is ideally made of an engineering plastics material which has good strength and resistance to impact and can absorb vibration, which is helpful to reduce the noise generated by the gear train as well. The buffer holes 57 aid molding of the drive plate by providing relief when the plastics material is cooling in the mould to reduce distortion of the mounting hole 55 . [0038] In the description and claims of the present application, each of the verbs “comprise”, “include”, “contain” and “have”, and variations thereof, are used in an inclusive sense, to specify the presence of the stated item but not to exclude the presence of additional items. [0039] Although the invention is described with reference to one or more preferred embodiments, it should be appreciated by those skilled in the art that various modifications are possible. Therefore, the scope of the invention is to be determined by reference to the claims that follow.

A motor assembly includes a motor, a force transmission structure comprising a drive plate and a shaft, and a gear train connecting the motor to the drive plate for transmitting rotation of the motor to the drive plate. The drive plate has a mounting hole with at least three sections interconnected with one another at a common area, the shaft has a toothed portion with at least three teeth fittingly received in the sections of the mounting hole of the drive plate such that the shaft is rotated with the drive plate.

big_patent

CROSS REFERENCE TO RELATED APPLICATIONS This application claims the benefit of and priority to U.S. Provisional Patent Application Ser. No. 60/275,032, entitled “Method and Apparatus for Multipath Signal Detection, Identification, and Monitoring for WCDMA Systems,” filed Mar. 12, 2001, which is incorporated herein by reference in its entirety. BACKGROUND OF THE INVENTION 1. Field of Invention The present invention is generally related to wireless communication systems and, more particularly, is related to systems and methods for detection, identification, and monitoring of multipath signals in wideband code division multiple acess (WCDMA) systems. 2. Related Art With the increasing availability of efficient, low cost electronic modules, mobile communication systems are becoming more and more widespread. For example, there are many variations of communication schemes in which various frequencies, transmission schemes, modulation techniques and communication protocols are used to provide two-way voice and data communications in a handheld telephone like communication handset. The different modulation and transmission schemes each have advantages and disadvantages. The next generation of wireless communication is referred to as 3G, which stands for third generation. 3G refers to pending improvements in wireless data and voice communications through a variety of proposed standards. One goal of 3G systems is to raise transmission speeds from 9.5 kilobits (Kbits) to 2 megabits (Mbits) per second. 3G also adds a mobile dimension to services that are becoming part of everyday life, such as Internet and intranet access, videoconferencing, and interactive application sharing. This advancement in wireless communication necessitates improvements in the area of signal detection, identification, and monitoring of multipath signals, which are two or more identical signals from the same antenna reaching the receiver at different times due to taking different paths from the antenna to the receiver. SUMMARY The present invention provides a method and system for generating a mobile time reference for a portable transceiver. Briefly described, one embodiment of the system comprises an antenna, a radio frequency subsystem, and a baseband subsystem. The radio frequency subsystem is coupled to the antenna and includes a high frequency oscillator and a low frequency oscillator. The baseband subsystem is coupled to the radio frequency subsystem and includes a free running counter coupled to the high frequency oscillator and the low frequency oscillator. The free running counter provides a mobile time reference to the system and has a wake mode and a sleep mode. During the wake mode the free running counter uses the high frequency oscillator to generate the mobile time reference, and during the sleep mode the free running counter uses the low frequency oscillator to maintain the mobile time reference. The present invention can also be viewed as providing a method of generating a mobile time reference. In this regard, one embodiment of such a method, can be broadly summarized as including the steps of providing a high frequency clock, providing a low frequency clock, generating a mobile time reference using the high frequency clock, maintaining the mobile time reference using the low frequency clock when the high frequency clock is not available, and continuing to generate the mobile time reference using the high frequency clock when the high frequency clock is again available. Other systems, methods, features, and advantages of the present invention will be or become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the present invention, and be protected by the accompanying claims. BRIEF DESCRIPTION OF THE DRAWINGS Many aspects of the invention can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present invention. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. FIG. 1 is a block diagram illustrating one embodiment of a third generation portable transceiver according to the present invention. FIG. 2 is a block diagram of a free running counter in the WCDMA modem of FIG. 1 . FIG. 3 is a block diagram of the WCDMA modem of FIG. 1 including the multipath monitor and multipath radio signal recovery circuit. FIG. 4 is a flow diagram of one embodiment of a method of providing a mobile time reference. DETAILED DESCRIPTION Having summarized various aspects of the present invention, reference will now be made in detail to the description of the invention as illustrated in the drawings. While the invention will be described in connection with these drawings, there is no intent to limit it to the embodiment or embodiments disclosed therein. On the contrary, the intent is to cover all alternatives, modifications and equivalents included within the scope of the invention as defined by the appended claims. FIG. 1 is a block diagram illustrating a simplified 3G portable transceiver 20 . In one embodiment, portable transceiver 20 can be, for example but not limited to, a portable telecommunication handset such as a mobile cellular-type telephone. Portable transceiver 20 includes antenna 22 connected to radio frequency subsystem 24 . RF subsystem 24 includes receiver 26 , receiver baseband analog processor (BAP) 28 , transmitter 30 , transmitter BAP 32 , high frequency oscillator (which may be implemented as a temperature controlled crystal oscillator (TCXO)) 34 , low frequency oscillator (which may be a 32 KHz crystal oscillator (CO)) 36 , and transmitter/receiver switch 38 . Antenna 22 transmits signals to and receives signals from switch 38 via connection 40 . Switch 38 controls whether a transmit signal on connection 42 from transmitter 30 is transferred to antenna 22 or whether a received signal from antenna 22 is supplied to receiver 26 via connection 44 . Receiver 26 receives and recovers transmitted analog information of a received signal and supplies a signal representing this information via connection 46 to receiver BAP 28 . Receiver BAP 28 converts these analog signals to a digital signal at baseband frequency and transfers it via bus 48 to baseband subsystem 50 . Baseband subsystem 50 includes WCDMA modem 52 , microprocessor 54 , memory 56 , digital signal processor (DSP) 58 , and peripheral interface 60 in communication via bus 62 . Bus 62 , although shown as a single bus, may be implemented using multiple busses connected as necessary among the subsystems within baseband system 50 . WCDMA modem 52 , microprocessor 54 , memory 56 , and DSP 58 provide the signal timing, processing, and storage functions for portable transceiver 20 . Memory 56 may include dual port random access memory (RAM) shared by microprocessor 54 and DSP 58 . Peripheral interface 60 provides connection to baseband subsystem 50 for a variety of items. These items may include, but are not limited to, devices that are physically part of portable transceiver 20 , such as speaker 62 , display 64 , keyboard 66 , and microphone 68 , and devices that would be externally connected to portable transceiver 20 , such as personal computer (PC) 70 , test system 72 , and host system 74 . Speaker 62 and display 64 receive signals from baseband subsystem 50 via connections 76 and 78 , respectively, as known to those skilled in the art. Similarly, keyboard 66 and microphone 68 supply signals to baseband subsystem 50 via connections 80 and 82 , respectively. PC 70 , test system 72 , and host system 74 all receive signals from and transmit signals to baseband subsystem 50 via connections 84 , 86 , and 88 , respectively. Baseband subsystem 50 provides control signals to RF subsystem 24 via connection 90 . Although shown as a single connection 90 , the control signals may originate from WCDMA modem 52 , microprocessor 54 , or DSP 58 , and are supplied to a variety of points within RF subsystem 24 . These points include, but are not limited to, receiver 26 , receiver BAP 28 , transmitter 30 , transmitter BAP 32 , TCXO 34 , and switch 38 . WCDMA modem 52 receives the digital signal from receiver BAP 28 on bus 48 and provides a digital signal to transmitter BAP 32 on bus 92 . Transmitter BAP 32 converts this digital signal to an analog signal at radio frequency for transmission on connector 94 to receiver 30 . Receiver 30 generates the transmit signal which is provided to antenna 22 via connectors 40 , 42 and switch 38 . The operation of switch 38 is controlled by a control signal from baseband subsystem 50 via connection 90 . In accordance with an embodiment of the invention, TCXO 34 provides a clock to receiver 26 , transmitter 30 , and WCDMA modem 52 via connectors 96 , 98 , and 100 , respectively, and CO 36 provides on connector 102 a 32 KHz clock to WCDMA modem 52 . These two clocks are used by WCDMA modem 52 to create a mobile time reference. This mobile time reference is constantly running and has an accuracy of approximately 32 nanoseconds. Referring now to FIG. 2 , a portion of WCDMA modem 52 is shown illustrating free running counter (FRC) 104 which generates the mobile time reference for use by portable transceiver 20 . FRC 104 is provided with a clock signal from the TCXO on line 100 and a clock signal from the CO on line 102 . The clock signal from the TCXO on line 100 can be a 30.72 MHz, and the clock signal from the CO on line 102 can be 32 KHz. FRC 104 includes TCXO circuit 106 , phase locked loop (PLL) 108 , counter 110 , drift estimator 112 , and correction circuit 114 . TXCO circuit 106 using the 30.72 MHz clock generates the mobile time reference. The 32 kHz clock is phase locked to the 30.72 MHz clock for improved performance using PLL 108 . Counter 110 counts the cycles of the 32 KHz clock. Drift estimator 112 provides an estimate of the drift of the 32 KHz clock for use by correction circuit 114 . The estimate of drift includes both the drift and bias of the clock as provided by a Kalman estimation as known to those having ordinary skill in the art. FRC 104 operates in two time domains, 30.72 MHz or 32 KHz, depending on whether the portable transceiver 20 is in active mode or idle mode, respectively. In active mode the portable transceiver is actively transmitting, receiving, processing, or looking for signals. During idle mode the portable transceiver powers down most of its circuits to conserve power. The CO 36 is always on providing a continuous 32 KHz clock signal to FRC 104 , but the TCXO 34 is turned off during idle mode. Now referring to FIG. 3 , a block diagram of the WCDMA modem 52 is shown. When the portable transceiver is in active mode, FRC 104 provides the mobile time reference including clock-phase, chip-counter, and slot-counter on bus 150 to primary sync searcher 116 , secondary sync searcher 118 , gold code searcher 120 , and single-path processor (SPP) controller 122 as shown in FIG. 3 . A 10 millisecond radio frame is divided into 15 slots (slot-counter 0 – 14 ). Each slot includes 2,560 chips (chip counter 0 – 2 , 559 ). Each chip contains 8 ticks (clock-phase 0 – 7 ). FRC 104 also generates a frame counter ( 0 – 511 ) for the mobile time reference by counting the frames that occur within a 5.12 second period. Also, the drift estimate is continually updated when the portable transceiver is in active mode. When transitioning into the idle mode, a sleep/awake control signal on line 124 from the microprocessor to FRC 104 transitions to a low state. Counter 110 is reset and begins counting the rising edges of the 32 KHz clock signal. At the next rising edge of the 32 KHz clock after the sleep/awake control signal transitions to a low state, the current mobile time reference and drift estimate from TXCO circuit 106 is provided to correction circuit 114 . At this time the portable transceiver goes into idle mode. During each subsequent count, correction circuit 114 updates the mobile time reference using the count and the drift estimate. Thus, the mobile time reference and drift estimate is maintained during the idle mode. When transitioning to the active mode, the sleep/awake control signal transitions to a high state. At the next rising edge of the 32 KHz clock, the updated mobile time reference maintained in correction circuit 114 is provided to TCXO circuit 106 and FRC 104 begins providing the mobile time reference for the portable transceiver using the 30.72 MHz clock and the updated mobile time reference as a starting point. The idle time may extend into a number of seconds, and the active time with no paging detected could be as long as 5 milliseconds. Maintaining the mobile time reference during idle mode allows the portable transmitter to quickly transition to an active state, which translates into a shorter duration in the active state, thus reducing power consumption and extending battery life. Maintaining the mobile time reference to a 32 nanosecond accuracy improves the efficiency of detecting, identifying, and monitoring the incoming multipath signals. The FRC provides a timing reference for the portable transceiver system and for acquiring the parameters required to recover the multipath signals and operate a nultipath signal receiver. WCDMA modem 52 includes FRC 104 , receiver equalizer 126 , multipath monitor 128 , and multipath radio signal recovery circuit 130 . The mobile time reference from FRC 104 is provided to both multipath monitor 128 , such as a code acquisition system, and multipath radio signal recovery circuit 130 , such as a RAKE receiver as known to those having ordinary skill in the art. The digital signal from the receiver BAP 28 is provided to receiver equalizer 126 and equalized prior to being provided on bus 144 to multipath monitor 128 and multipath radio signal recovery circuit 130 . Multipath monitor 128 includes primary sync searcher 116 , secondary sync searcher 118 , and gold code searcher 120 , and provides information regarding these searches to the microprocessor. In one embodiment, multipath radio signal recovery circuit 130 includes SPP controller 122 , twelve SPPs 132 , twelve first-in first-out (FIFO) circuits 134 , twelve phase correctors 136 , deskewing and timing controller (DTC) 138 , four maximal rate combiners (MRC) 140 , and four demodulation units 142 . SPP controller 122 maps up to twelve multipath signals to SPPs 132 and provides a start command on bus 146 to each of the SPPs 132 . Each SPP recovers and tracks incoming clock information relative to a basestation, provides the clock information to DTC 138 , and provides phase estimation for both single and multiple basestation antennas to the corresponding phase corrector 136 . The clock information provided to DTC 138 is in the same form as the mobile time reference having a clock-phase, a chip-counter, and a slot-counter. The mapped equalized signal is passed through each SPP 132 to the corresponding FIFO 134 . Each FIFO 134 has a subperiod of 512 chips. Each radio frame includes 38,400 chips or seventy-five subperiods of 512 chips. DTC 138 using the clock information from each of SPPs 132 provides a read address and read strobe signal from bus 148 to each SPP, which time aligns the outputs of FIFOs 134 relative to one another. The operation of DTC 138 is a complex PLL operation. The output of each FIFO 134 is provided to the corresponding phase corrector 136 which corrects the phase of the signal using the phase estimation provided by the corresponding SPP 132 . The outputs of each phase corrector 136 is mapped to one of the four MRCs 140 . Each MRC 140 combines the signals mapped to it to increase the strength of the signal. The strengthened signal from each MRC 140 is provided to the corresponding demodulation unit 142 . Demodulation unit 142 recovers information from the signal on up to eight channels. Thirty-two different channels are provided for information recovery. One of the benefits of the above recovery system is that the information is not recovered from the signals until the signals are time aligned improving the efficiency of the recovery. Another benefit is that signals from either or both of the antennas from a basestation can be utilized and mapped to an SPP. Still another benefit is the ability to align the signals from asynchronous basestations, i.e. basestations operating using different clocks. The present invention provides a wideband spread spectrum multipath signal detector, identification mechanism, and multipath monitoring technique that monitors signal strength from a plethora of asynchronous transmitters within a network in the presence of a moving time base, slotted operations, and effects of the mobile radio channel. The time base is moving with movement of the portable transceiver. Slotted operations are utilized to spread the required processing out over multiple active periods. The system performs matched filtering of the primary synchronization code and creates a non-coherent energy measurement that is transformed into the log2-domain to reduce memory requirements for multiple hypotheses of slot level timing. Hypotheses are low pass filtered to enhance the probability of detection of signals that are candidates for further processing. The system recovers the transmitted code groups and frame timing for the received signal components. A parallel set of correlators performs the final identification of the despreading code over all possible codes in parallel. Timing is maintained in the system through use of Kalman estimation that recovers clock drift and bias when utilizing low cost crystals for standby, low power consumption, and slotted operations. A fast wakeup mechanism recovers multiple hypotheses in parallel to arrive quickly at a time base that can initiate subsequent demodulation of the spread spectrum signal, thus reducing power consumption and minimizing duty cycle of the slotted mode operations. A method for recovery of network timing in the presence of frequency uncertainty, that uses energy measurements form the primary synchronization code, allows user equipment to detect, identify, and perform subsequent demodulation of the downlink signal. Referring now to FIG. 4 , one embodiment of a method of providing a mobile time reference for the portable transceiver of FIG. 1 is shown. Initially, a high frequency clock (30.72 MHz) is provided by a temperature controlled crystal oscillator as shown in block 200 . In block 202 , a low frequency clock is provided by a crystal oscillator operating at 32 KHz. A mobile time reference is generated using the high frequency clock in block 204 . The mobile time reference includes a clock-phase signal, a chip-counter, a slot-counter, and a frame-counter. As shown in block 206 , the mobile time reference is maintained using the low frequency clock, when the high frequency clock is not available. Finally, when the high frequency clock is again available, the mobile time reference continues to be generated with the high frequency clock and the maintained mobile time reference as a starting point in block 208 . The low frequency clock is phase locked to the high frequency clock, and an estimate of the drift and bias of the low frequency clock is made using a Kalman estimation. During the step of maintaining the mobile time reference, the mobile time reference is updated using the cycles of the low frequency clock counted when the high frequency clock is not available and the estimated drift/bias of the low frequency clock. Although an exemplary embodiment of the present invention has been shown and described, it will be apparent to those of ordinary skill in the art that a number of changes, modifications, or alterations to the invention as described may be made, none of which depart from the scope of the present invention. All such changes, modifications, and alterations should therefore be seen as within the scope of the present invention.

Methods to generate a mobile time reference are provided. A representative method includes providing a high frequency clock, providing a low frequency clock, generating a mobile time reference using the high frequency clock, maintaining the mobile time reference using the low frequency clock when the high frequency clock is turned off, and continuing to generate the mobile time reference using the high frequency clock when the high frequency clock has been turned back on. Systems and other methods are also provided.

big_patent

BACKGROUND OF THE INVENTION Protective helmets having hard outer shells for use in various military, industrial or other applications are well known in the art. In such helmets, it is generally desirable to provide a resilient liner assembly between the outer shell and the wearer's head to help absorb shock. While straps or similar elements have customarily been used in the past for this purpose, they must be adjustable to accomodate various head sizes, resulting in some wobbling from front to back or from side to side. Various proposals for custom-fitted liner assemblies have been suggested in an attempt to overcome this defect. According to one known method of making a custom-fitted helmet, disclosed in Morton U.S. Pat. No. 3,882,546, the outer helmet shell is spaced a suitable distance from the wearer's head and foam is injected into the region between the outer shell and an elastic layer closely overlying the wearer's head. The necessity of directly handling the foaming agent limits the utility of this method in the field. According to another method of making a custom-fitted helmet, disclosed in Chisum U.S. Pat. No. 4,100,320, the helmet liner is preformed with a plurality of adjacent pairs of cells respectively containing the first and second components of a foamable mixture. After the liner is placed between the helmet shell and the wearer's head, the cell partitions separating the first and second components are removed to initiate the foaming process. While this method avoids direct exposure to the liner foam, the complexity and hence expense of the preformed liner limit its practical application. Both of those methods, moreover, are one-shot procedures in that they do not permit subsequent adjustment of the liner to accommodate a different wearer or a changed head size. Yet another method is disclosed in the commonly assigned application of Michael R. Lavender, Ser. No. 132,817, filed Mar. 24, 1980, now abandoned in favor of continuation application Ser. No. 382,420, filed May 27, 1982. That application discloses an individually fitted helmet liner having a plurality of layers, each of which consists of a thermoplastic sheet formed with an array of pockets which individually receive hollow epoxy balloon spacer elements. Adjacent layers are arranged with the spacer elements of one layer in register with the spaces between the elements of an adjacent layer, so that the layers nestle together to an extent determined by the degree to which the sheets are permanently deformed in the regions of the spheres of adjacent layers. The sheets making up the liner are elastic at normal temperatures but are plastically deformable at elevated temperatures to permit custom fitting to a changed head size simply by fitting the helmet after heating the layers to a suitable softening temperature. While the helmet liner described above fulfills the objects of its inventor, there remain certain areas for improvement. First, the necessity of arranging the adjacent layers with the spheres of one layer in register with the spaces between the spheres of an adjacent layer entails a relatively expensive and time-consuming manufacturing step of maintaining the various layers in proper register. Second, the relative incompressibility of the hollow epoxy spheres results in a tendency of the completed helmet to shift its position relative to the wearer's head, owing to an inability of the liner to conform fully to the contours of the wearer's head. Finally, drawstrings or the like are required to maintain the sheets in tension during size adjustment. SUMMARY OF THE INVENTION One of the objects of our invention is to provide an individually fitted helmet liner which may be fitted to a wearer's head rapidly and in a simple manner. Another object of our invention is to provide an individually fitted helmet liner which may be refitted to accommodate a changed head size. Still another object of our invention is to provide an individually fitted helmet liner which has uniform and hence predictable structural characteristics. A further object of our invention is to provide an individually fitted helmet liner which does not require trimming after fitting. Still another object of our invention is to provide an individually fitted helmet liner which is relatively simple and inexpensive to manufacture. A further object of our invention is to provide an individually fitted helmet liner which resists the tendency to shift position on the wearer's head. A still further object of our invention is to provide an individually fitted helmet liner which does not have to be maintained in tension during size adjustment. Other and further objects will be apparent from the following description. In general, our invention contemplates a helmet liner in which a plurality of layers, each of which consists of an elastic thermoplastic sheet formed with an array of pockets, are arranged in superposed contacting relationship with one another, with the pockets being open and unfilled to allow their deformation in response to compressive contact with an adjacent layer. The liner is fitted to an individual wearer's head by heating the sheets to a plastic state, placing the liner between an outer fixture and the wearer's head to deform the sheets to the proper extent, and removing the liner from the wearer's head when the liner has cooled to a rigid, nonplastic state. By leaving the liner pockets open and unfilled rather than filling them with relatively imcompressible spacer elements, we are able to provide a helmet liner which, while sufficiently rigid to provide the necessary spacing between the outer shell and the wearer's head, is nevertheless compliant enough to smooth out the effects of relative layer alignment. Thus, in contrast to the liner disclosed in application Ser. No. 132,817, the pockets of a given layer do not have to be maintained in register with the spaces between the pockets of an adjacent layer, and the manufacturing process can be therefore greatly simplified. Because of the increased bulk compliance of the assembled liner, our liner also conforms more readily to the contours of the wearer's head, minimizing the tendency for the outer helmet to shift in position. Finally, we have found that by having the liner pockets open and unfilled, we are able to eliminate the drawstrings used in the previous liner to maintain the liner in tension during size adjustment. Our liner, by contrast, need merely be maintained in compression during the fitting procedure to deform the layers to the proper extent. BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings to which reference is made in the instant specification and in which like reference characters are used to indicate like parts in the various views: FIG. 1 is a perspective view of a helmet incorporating our individually fitted liner. FIG. 2 is an enlarged fragmentary section of a peripheral portion of the liner of the helmet shown in FIG. 1. FIG. 3 is an enlarged fragmentary section of a central portion of our helmet, showing the relative arrangement of the outer shell and the thermoplastic liner. FIG. 4 is a perspective view of the inner thermoplastic liner of the helmet shown fragmentarily in FIG. 3. DESCRIPTION OF THE PREFERRED EMBODIMENT Referring first to FIG. 1, a preferred embodiment of our helmet, indicated generally by the reference numeral 66, includes an outer shell 68 and an inner thermoplastic liner 74. The shell 68 comprises a rigid outer layer 70, formed of a suitable reinforced plastic material, and an energy-absorbing polystyrene foam liner 72 carried inside the outer layer 70, as shown in FIG. 3. Referring now also to FIGS. 2 to 4, inner liner 74, which is releasably secured to the shell 68 by any suitable means, such as the means to be described, comprises foursheet layers 76, 78, 80 and 82, formed of a suitable elastic thermoplastic material. Suitable thermoplastic materials include ethylene-vinyl acetate, a copolymer resin available from E. I. du Pont de Nemours & Company under the trademark "Elvax", and the copolymer of ethylene and methacrylic acid available from the same source under the trademark "Surlyn"; the latter material is an ionomer resin. Each of the layers 76, 78, 80 and 82 is a vacuum-formed over a hemispherical dome (not shown) similar to the mold shown in application Ser. No. 132,817, but with bumps or protuberances formed at regular intervals across the surface of the dome so that the resulting vacuum-formed sheet comprises a flat portion 84 with regularly spaced hollow spherical protuberances 86. Preferably, a larger-diameter dome is used to vacuum-form outer layers 76 and 78, while a smaller-diameter dome is used to form the inner layers 80 and 82. Layers 76, 78, 80 and 82 are arranged as shown in FIG. 3, with the flat portions of layers 76 and 78 and of layers 80 and 82 in contact with each other. In contrast to the helmet assembly shown in that earlier application, the protuberances 86 of layers 78 and 80 need not interdigitate with each other, the compliance of the unfilled protuberances 86 being sufficient in itself to afford the necessary accommodation between layers 78 and 80. After layers 76, 78, 80 and 82 are vacuum-formed in the manner described above, they are trimmed to the required shape and their edges glued or otherwise secured together as shown in FIG. 2. A hemispherically patterned layer 88 of comfort foam is then glued along the inside edge of inner thermoplastic layer 82. A sewn knit fabric inner lining or cover 90 with a woven fabric outer peripheral band or edging 92 is then attached to the assembly of layers 76 to 88 by gluing the peripheral band 92 to the outside surface of the layer assembly about one inch up from the trimmed lower edge, as also shown in FIG. 2, so that the lining 90 covers the inner surface of foam layer 88 and band 92 extends along the periphery of outer thermoplastic layer 76. Peripheral band 92 carries front, rear and side fasteners 94 which mate with complementary fasteners 96 (FIG. 1) carried on the underside of the polystyrene foam liner 72 of the shell 68. Suitable such fasteners include, for example, the hook-and-loop fasteners sold by American Velcro, Inc., under the trademark "Velcro". Preferably the overall inside dimensions of the liner 74 should not change more than about plus or minus 1/4 inch when fitted to individual subjects. To accommodate a typical range of expected head sizes while maintaining this standard, we form the liner 74 in six basic sizes, using differently sized headforms, such as the headform shown in application Ser. No. 132,817, to determine the size and shape of the different layers during fabrication and assembly. Adjacent thermoplastic layers 76, 78, 80 and 82 nestle together to an extent determined by the degree of permanent deformation of the sheets making up the layers. By deforming the sheets to the desired extent while in a plastic state and then cooling the sheets to cause them to set with that deformation, the effective thickness of the assembly of layers 76, 78, 80 and 82 may be readily adjusted within a particular sizing range. To custom-fit the liner 74 to the head of the wearer, the liner is heated in an oven at 200° F. for about 7 to 10 minutes, the exact heating time and temperature depending on the particular thermoplastic used. After the liner has been heated in this manner, it is placed inside the shell 68 or a fitting fixture (not shown) by suitable alignment of the fasteners 94 with the corresponding fasteners 96 carried by the helmet or fixture. The shell 68 with the liner 74 inside is then placed on the individual's head and pressed firmly downward for about 3 minutes, or until the liner 74 has cooled to a temperature at which it has sufficiently solidified. After the layers 76, 78, 80 and 82 cool to a rigid, nonplastic state, the sheets forming the layers retain their plastic deformation to provide the desired accommodation to the wearer's head. This procedure may be followed repeatedly to refit the liner 74 either to a different individual or to the same individual with a changed head size, so long as the new size is at least as large as the previous head size fitted and in the same size range. Thus, our liner readily accommodates size changes due, for example, to changed hair length or bumps on the head. It will be seen that we have accomplished the objects of our invention. Our helmet liner is simple and inexpensive to manufacture, and may be fitted to a wearer's head rapidly and in a simple manner. Our helmet liner may be refitted to accommodate a changed head size, while resisting the tendency to shift position on the wearer's head. Our helmet liner does not require the use of drawstrings or the like during fitting or require trimming afterward. It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of our claims. It is further obvious that various changes may be made in details within the scope of our claims without departing from the spirit of our invention. It is, therefore, to be understood that our invention is not to be limited to the specific details shown and described.

An individually fitted helmet liner includes a plurality of superposed contacting layers, each of which consists of a thermoplastic sheet formed with an array of pockets which are open and unfilled to allow their deformation in response to compressive contact with an adjacent layer. The liner is fitted to an individual wearer's head by heating the sheets to a plastic state, placing the liner between an outer shell and the wearer's head, and pressing down on the outer shell to deform the sheets to the proper extent.

big_patent

This is a division of application Ser. No. 796,953, filed May 16, 1977, now U.S. Pat. No. 4,127,234. BACKGROUND OF THE INVENTION 1. Field of the Invention The invention related to multiorifice structures and a method of fabrication and, more particularly, to a multiorifice structure spray disc for use in conjunction with an automotive type fuel injector valve for atomizing the fuel being injected into an internal combustion engine. 2. Prior Arts The use of multiorifice structures in connection with nozzles for dispersing or atomizing an exiting fluid is well known in the art. Such multiorifice structures are found in a wide variety of applications ranging from old fashion sprinkling cans for watering a garden to sophisticated fuel injector valves for internal combustion engines. Whether the multiorifice structure merely disperses the fluid as with the sprinkling can or atomizes the fluid as in the fuel injector nozzle application depends upon several factors, one of which is the size of the apertures, as well as force with which the fluid is ejected. Atomization is best accomplished when fluid is ejected from relatively small apertures with relatively high forces. For automotive fuel injector applications, small apertures having effective diameters in the range from several hundred to less than one hundred microns appear to give the desired atomization without the need of having the fuel pressurized above tolerable limits. Unfortunately, multiorifice structures having apertures in ths size range are difficult to manufacture and their cost is prohibitive to meet the high volume, low cost needs for the automotive market. Various techniques for making the desired multiorifice structure, such as drilling or punching, are impractical. Photoetching or chemical machining appear as a better approach but due to the depth of the apertures required, the desired uniformity of the apertures is difficult to achieve. Alternatively, the fusion of small diameter tubes disclosed by Roberts et al in U.S. Pat. No. 3,737,367 (June 1973) appears as the best approach taught by the prior art. The disadvantage of this approach is that the resultant aperture passages are parallel to each other and therefore the spray cone of the emitted fuel is limited. The divergence of the spray pattern emitted by the Roberts type structure can be increased by coining the structure to produce a curved surface. Alternatively, the parallel tubes in various sections of the structure may be angularly disposed as taught by Roberts et al in U.S. Pat. No. 3,713,202 (January 1973). Atomization may also be obtained by twisting the individual rows of tubes, as taught by A. L. R. Ellis in U.S. Pat. No. 1,721,381 (June 1929). In this patent the alterante rows are twisted in the opposite direction to incease the turbulance thereby enhancing the mixing and combustion of the emitted gases. Ellis further teaches the use of the interstices between the tubes to pass the oxidizing gas which supports the combustion of the fuel gas passing through the tubes. E. E. Fassler in U.S. Pat. No. 3,602,620 (August 1971) teaches a thermal lance in which the oxidizing gas is fed to the tip of the lance through the interstices formed by twisting solid wires about a core. The twisted rods in this patent provide a tortuous path to impede the gas flow. SUMMARY OF THE INVENTION The invention is a multiorifice wafer structure having a plurality of angularly disposed passages and a method for making the multiorifice structure. The structure is made by fusing concentric layers of solid rods interspaced with cylindrically shaped members wherein each successive layer of rods is disposed at a progressively larger angle with respect to the axis of the fused assembly. The fused assembly of cylinders and rods is then cut into relatively thin wafers wherein the interstices formed between the fused layers of rods and the cylindrical members form a plurality of angularly disposed passageways in which angles of the passageways increase progressively as a function of their distance from the center of the structure. The thickness of the wafer is determined by the effective aperture of the interstices and is sufficient to impart to the fluid passing through the interstices a directional component parallel to the angular displacement of the rods with respect to the common axis of the structure. The object of the invention is a multiorifice structure having a plurality of passageways angularly disposed with respect to a common axis. Another object of the invention is a multiorifice structure in which the angular displacement of the passageways increases as a function of the displacement of the passageway from the center of the structure. Another object of the invention is a flat multiorifice spray plate for a fuel injector valve in which the fuel passing through the spray plate is ejected at an angle which is a function of orifices distance from the center of the structure. Still another object is a method for making a multiorifice structure which comprises fusing concentric layers of alternating cylindrical members and angularly disposed rods into an integral assembly, and slicing such integral assembly in a direction normal to the axis of said cylindrical members to produce a plurality fo multiorifice structures wherein the interstices between said rods and cylinders form a plurality of angularly disposed passageways. These and other advantages of the invention will become apparent from a reading of the following detailed description in conjunction with the drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective of the disclosed multiorifice structure. FIG. 2 is an exploded side view showing the angular disposition of the sequential layers of rods. FIG. 3 is an enlarged section of the multiorifice structure. FIG. 4 is an exploded view illustrating the structure of the internal layers of a composite assembly. FIG. 5 is an enlarged partial section showing a structure fabricated from coated rods and coated cylindrical members. FIG. 6 is a side view of a fused composite and the resultant multiorifice structures cut therefrom. DETAILED DESCRIPTION OF THE INVENTION An exemplary embodiment of the invention is illustrated in FIG. 1. The multiorifice structure, designated generally by the numeral 10, is a wafer comprising alternating concentric layers of solid rods 12 and cylindrical members 14 fused or sintered into an integral assembly. Each layer of rods 12 comprises a plurality of individual rods 16 angularly disposed with respect to the axis of the concentric cylindrical members. In the preferreed embodiment, each concentric layer of rods 12, starting from the center of the structure is disposed a greater angle with respect to a core rod 18 than the preceding layer as illustrated in FIG. 2. In FIG. 2, Row A designates the core rod 18 which is axially disposed with respect to the wafer. Row B is a side view of just the first or innermost layer of rods 16. Row C designates the next sequential layer of rods and Rows D and E represent the next sequential layers of rods. It is to be understood that only four layers of rods are used to illustrate the concept, and that in actual practice the structure may have from two or three layers to well over 100 layers. Further, the angles at which the rods 16 are disposed with reference to the core rod 18 may be different than the angles shown. The angles shown are illustrative and the actual angular disposition of each layer or rods with respect to the axis of the multiorifice structure depends ultimately on the end use of the structure including the desired dispersion angle or spray cone of the fluid emitted from the structure. As is obvious, increasing the angular displacement of the rods will increase the resultant dispersion capabilities of the structure. Referring now to FIG. 3, there is shown an enlarged section of a portion of the multiorifice structure. As previously described, the structure comprises a plurality of layers 12 of rods 16 separated by cylindrical members 14. The interstices or interstitial spaces 20 between the individual rods 16 and the cylindrical members 14 form a plurality of generally triangularly shaped passageways through the structure. These interstices 20 constitute the orifices through which the fluid to be dispersed or atomized flows. The thickness of the structure is a function of the effective aperture of the interstices and is selected such that the fluid passing therethrough will, upon exiting the structure, have a directional component parallel to the axis of the interstices. Normally, the thickness of the multiorifice structure will be about 10 or more times the size of the individual orifices. One advantage of the disclosed structure is that the triangular shaped orifices are more effective in the atomization of the exiting fluid than the circular orifices of the prior art. As is well known, surface tension forces acting on the exiting fluid tend to cause the exiting fluid stream to oscillate which eventually cause the exiting stream of fluid to break up in small droplets. The greater the distortion of the exiting stream from the natural spherical configuration of a free fluid, the greater will be the surface tension forces acting on the exiting fluid. As a result, the exiting fluid will be caused to vibrate more vigorously and break up into smaller particles than would be achieved with circular orifices having the same effective aperture. Another factor to be considered is the overall uniformity of the apertures formed by this method over conventional drilling and/or photoetching techniques. The rods 16 are normally made by extruding techniques which result in very precise tolerances on its diameter, therefore, the triangular apertures resulting from the disclosed configuration will have a very uniform size. FIGS. 4 and 5 illustrate a very simple and economical method for fabricating the disclosed multiorifice structure. Referring to FIG. 4, a central or core rod 18 is circumscribed by six or more rods or wires 16'. The first layer of rods 16' are twisted about the core and rod 18, so that their axis are disposed at a predetermined angle with respect to the axis of core rod 18. The angle α may be 5° as indicated in FIG. 2-B or any other desired angle. Core rod 18 and twisted rods 16' are then sheathed in a cylindrical member 14' whose internal diameter is equal to diameter of the core rod 18 plus two times the diameter of the rods 16' so that the rods 16' are in physical contact with the external surface of the core rod 18 and the internal surface of the cylindrical member 14'. The external diameter of cylindrical member 14' is seleced so that an integral number of rods 16" of the same diameter as rods 16' completely surround member 14' with their external surfaces in contact with each other. A second layer of rods or wires 16" are also twisted about the external surface of the cylindrical member 14' and sheated in a second cylindrical member 14". The twisted rods on the second layer are angularly disposed with regard to the core rod 18 at an angle β which may be the same as α or may be different as shown in FIG. 2. The internal diameter of the cylindrical member 14" is selecetd so that the rods 16" will be encased between and in contact with the external surface of member 14' and the internal surface of member 14". The external diameter of member 14" is again selected so that an integral number of rods 16" of the same diameter as rods 16' will completely surround member 14 with their external surfaces in contact with the adjacent rods. In a like manner, the layer of rods 16" will be sheathed in a cylindrical member 14"' and so on until the composite structure of rods and cylindrical members has a diameter equal to the diameter of the desired multiorifice structure 10. The composite structure is then fused or sintered to form an integral structure 22 in which each rod is fused to each adjacent rod and to the surfaces of the bounding cylindrical members 14. To facilitate the fusion of the rods and the cylindrical members, the rods and cylindrical members may be coated with a thin layer of material having a lower melting temperature than the materials of the rods and cylindrical members, as shown in FIG. 5. This coating material may be deposited on the surface of the rods and cylindrical members by electroplating, dipping, vapor deposition or any other way known in the art. FIG. 5 is an enlarged section of the multiorifice structure in which the thickness of the coatings are exaggerated for illustrative purposes. Referring to FIG. 5, each rod 16 and cylindrical member 14 is coated with a thin layer of a material 24. For example, the rods 16 and cylindrical member may be made from a stainless or carbon steel and the coating material may be copper, nickel, tin, or any other suitable material having a lower melting temperature. It is recognized that the multiorifice structure need not be made from metals, and glass as well as plastic materials may be used. Further, it is not always necessary that both rods 16 and cylindrical members 14 be coated with the lower melting temperature material and alternatively, only one or other needs to be coated. Referring now to FIG. 6, the fused assembly 22 is sliced or cut using any of the known methods to produce a plurality of thin multiorifice structures 10 having the desired thickness. The sliced surfaces 26 of the multiorifice structures may subsequently be ground or polished to produce required surface finish or uniformity of thickness. Although the invention has been described and illustrated with reference to a particular configuration and method of manufacture, it is not contemplated that the invention be limited to the structure shown or the particular method of making discussed. It is recognized that those skilled in the art could conceive alternate embodiments wherein the cylindrical members could take alternate shapes or the single layer of rods be replaced by rods having noncircular cross-sections or even multiple layers of rods between the cylndrical members without departing from the spirit of the invention.

The invention is a multiorifice structure and method of manufacuture. The structure comprises a plurality of triangularly shaped orifices angularly disposed with respect to a common axis. The structure is formed by fusing together concentric alternating layers of cylindrical members and parallel rods angularly disposed with respect to the axis of the cylindrical members. The fused structure is sliced generally normal to its axis to produce a plurality of multiorifice wafers or discs. The interstices between the rods and the cylindrical members form a plurality of small triangularly shaped orifices particularly well suited to use as an atomizer for an internal combustion engine fuel injector valve.

big_patent

This is a Continuation of application Ser. No. 07/120,444 filed Nov. 13, 1987, now abandoned, which is a Divisional of application Ser. No. 06/768,374 filed on Aug. 22, 1985, now U.S. Pat. No. 4,727,038. BACKGROUND OF THE INVENTION The present invention relates to a method of manufacturing a semiconductor device, particularly, an insulated gate (MOS) field effect semiconductor device having a lightly doped drain (referred to as LDD hereinafter) structure. FIGS. 1A to 1C are cross sections showing main steps of a conventional manufacturing method of a semiconductor device of this type. In FIGS. 1A to 1C, a gate insulating film 2 and a gate electrode 3 are formed on a p-type silicon substrate 1, and a low density n-type region 4 used to form a source and a drain is formed by the ion-injection of a low density n-type impurity (1) under a low acceleration voltage while using the gate electrode as a mask (FIG. 1A). The ion-injection may be performed after the insulating film 2, except a portion thereof beneath the gate electrode 3, is removed as shown in FIG. 1A. Then, as shown in FIG. lB, an oxide film 9 is deposited using low pressure chemical vapor deposition (LPCVD). Thereafter, as shown in FIG. 1C, the oxide film 9, except a portion 10 thereof on a gate sidewall is removed by anisotropic reactive ion etching (RIE). Next a high density n-type region 5 is formed by ion injection of a high density n-type impurity (I) while using the gate electrode and the oxide portion as a mask. Thus, the LDD structure is formed. In the conventional LDD structure, it is difficult to determine the time at which the anisotropic RIE should be terminated. That is, since the oxide portion 10 on the sidewall is used as a mask in subsequent steps, the width L of the oxide portion is very important. If its etching is not terminated properly, the width L of the oxide portion becomes variable, and sometimes even the source/drain region is etched away. Further, if the low concentration n-type region 4 is formed by injecting, for example, phosphorous at 1×10 14 ions/cm 2 under 30 KeV, that region cannot be made amorphous. Therefore; a crystalline structure must be recovered by high temperature annealing; otherwise leakage currents may occur. Such annealing prevents the formation of shallow junctions, making minimization of the size of the device impossible. Another problem encountered in the conventional LDD structure prepared using an oxide film portion on the gate sidewall is that hot carriers may be injected into the oxide film portion 10 during a MOSFET operation, whereupon the low concentration n-type region 4 is depleted, causing the resistance thereof to be increased, and resulting in degradation of the transconductance of the device. Further, if it is attempted to minimize the size of the device by making the junctions shallower, resistances of the drain/source region, gate electrode and contacts are increased. SUMMARY OF THE INVENTION Thus, an object of the invention is to provide a method of fabricating a semiconductor device by which the controllability of the width of the oxide portion on the gate sidewall is improved. Another object of this invention is to provide a method of manufacturing a semiconductor device in which an LDD structure can be formed by a low temperature process. Another object of this invention is to provide a method of fabricating a semiconductor device by which degradation of the transconductance and increases of the resistances of elements such as the gate electrode due to hot-carrier injection into the oxide portion on the gate sidewall are prevented. According to the invention, the oxide portion on the sidewall of the gate is formed as follows. First, there is formed an insulating film on the gate electrode, on the substrate and on the sidewall therebetween, followed by forming a layer on the insulating film and anisotropically etching away the layer using RIE, except a portion thereof on the gate sidewall. This confromal layer may be made of polycrystalline silicon, oxide, high melting point metal, or silicides. In the manufacturing method of a semiconductor device according to the present invention, an insulating layer is formed on a gate electrode of a gate, and a low density region of the source/drain region is formed by ion injection of an impurity using an oxide film of the gate and an insulating film on the gate as a mask. After a conductive layer is formed on a wafer, it is anisotropically etched away to leave a portion thereof on the sidewall of the gate. After the mask is removed, the high density region of the source/drain region is formed by ion injection of an impurity. According to another embodiment of the present invention, the low density region is formed by impurity ion injection using the insulating film on the gate as a mask Then, the oxide film is formed on the sidewall of the gate using the insulating film as a mask, and then the high density region is formed by impurity ion injection using this insulating film and the insulating film on the gate as a mask. According to yet another embodiment of the invention, the oxide film portion on the sidewall of the gate, which is used as a portion of the mask for ion injection, is formed of a high melting point metal or a silicide of such a metal. According to still another embodiment of the invention, a conductive layer or polycrystalline semiconductor layer is formed after formation of an insulating film on a gate electrode, which is then anisotropically etched away using RIE to form the portion on the gate sidewall. The method of fabricating a semiconductor device according to this invention is further featured by siliciding a desired portion of the gate electrode or the gate electrode and the source/drain region in fabricating the insulated gate field effect semiconductor device having the LDD structure. BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1A to 1D illustrate main steps of a conventional method of fabricating a MOS field effect semiconductor device having an LDD structure; FIGS. 2A to 2D illustrate main steps of a first embodiment of the present invention; FIGS. 3A to 3C illustrate main steps of a second embodiment of the invention; FIGS. 4A to 4C illustrate main steps of a third embodiment of the invention; FIGS. 5A to 5C illustrate main steps of a fourth embodiment of the invention; FIGS. 6A to 6D illustrate main steps of a fifth embodiment of the invention; FIGS. 7A to 7D illustrate main steps of a sixth embodiment of the invention; FIGS. 8A to 8E illustrate a seventh embodiment of the invention; FIGS. 9A to 9E illustrate an eighth embodiment of the invention; FIG. 10A to 10E illustrate a ninth embodiment of the invention; FIGS. 11A to 11F illustrate a tenth embodiment of the invention; and FIGS. 12A to 12D illustrate an eleventh embodiment of the invention. DESCRIPTION OF PREFERRED EMBODIMENTS FIGS. 2A to 2D show the steps of a method of manufacturing a semiconductor device according to a first embodiment of the present invention. Further, reference numeral 20 depicts a gate electrode composed of a gate insulating film 2 and a polycrystalline silicon layer 3 formed on a p-type silicon substrate 1. A low density n-type region 4 is formed by injecting, for example, ions of As(I) at a density of 4×10 12 /cm 2 under an acceleration voltage of 35 KeV while using the gate electrode 20 as a mask, as shown in FIG. 2A. An oxide film 11 is deposited on the wafer by LPCVD to a thickness of 300Å as an etching stopper, and then a polycrystalline silicon layer 12 is deposited on the oxide film 11 by LPCVD, as shown in FIG. 2B. The polycrystalline silicon layer 12 is then anisotropically etched by RIE while monitoring light emission therefrom to detect the end point of RIE, at which time polycrystalline silicon 13 is left only on the gate sidewall, as shown in FIG. 2C. Then, the etching stopper oxide film 11 is removed and the high density n-type region 5 is formed by injecting ions of As(II) at a density of 4×10 15 /cm 2 under an acceleration voltage of 50 KeV with the gate electrode 20 and the polycrystalline silicon 13 on the gate side wall, the width of which is L, being used as a mask, resulting in an LDD structure, as shown in FIG. 2D. The device is completed by forming contact windows in the structure and adding wiring electrodes suitably. In this embodiment, since the polycrystalline silicon 12 is formed on the oxide film 11 which is formed on the silicon surface after the ion injection step using the gate electrode 20 as a mask and is anisotropically etched by RIE, it is possible to accurately detect the end point of the etching. As a result, the controllability of the width of the polycrystalline silicon 13 on the gate sidewall is improved, and the possibility of etching away the source/drain is avoided. In this embodiment, the width L of the polycrystalline silicon 13 on the gate side wall is determined by the thickness of the gate electrode. A second embodiment of the present- invention will now be described hereinafter. In FIGS. 3A to 3C, after forming a gate insulating film 2 and a polycrystalline silicon layer 3 on a p-type silicon substrate 1, a gate electrode 30 is formed by depositing an oxide film 21 by LPCV to a thickness of 0.1-0.5 microns (FIG. 3A). Subsequent steps to this are the same as those in the preceding embodiment, except that the thickness of the gate electrode is made larger than that of the corresponding structure of the preceding embodiment so that the width L' of the polycrystalline silicon portion 22 on the gate sidewall is larger than L, and ion injection of ions of phosphor (II) at a density of 4×10 12 /cm 2 under an acceleration voltage of 35 KeV is performed through the oxide film 11. In this case, with the presence of the oxide film 11 even after phosphorous ion injection, it is possible to remove the polycrystalline silicon 22 on the sidewall by using a further step of anisotropic etching. A p-type channel insulating gate (MOS) field effect semiconductor device can be fabricated according to this embodiment by changing the conductivity types of the substrate and the impurity. According to these embodiments, a step of forming the etching stopper composed of the oxide film and the polycrystalline silicon is employed and anisotropic RIE is performed with respect thereto. Therefore, it is easily possible to detect the end of etching and thus to control the width of the polycrystalline silicon on the gate sidewall. FIGS. 4A to 4C illustrate main steps of a third embodiment of the invention. In FIG. 4A, a gate insulating film 2 and a polycrystalline silicon film 3 which serves as a gate electrode are formed on a p-type silicon substrate 1, and then an insulating film, for example, a nitride film 21', is deposited thereon by LPCVD. Next, a gate is formed by photoetching these layers. Then, as shown in FIG. 4B, a gate side wall portion of an oxide film 15 is formed by a heat treatment with the nitride film 21' used as a mask, and a high concentration region 5 of a source/drain region is formed by injecting, for example, arsenide ions (III) at ions at a density of 4×10 15 /cm 2 while using the nitride film 14 and the gate sidewall oxide film 15 as a mask. Thereafter, as shown in FIG. 4C, the nitride film 21' and the sidewall oxide 15 are removed, and then a low concentration region 4 of the source/drain is formed by injecting, for example, phosphor ions (IV) at a density of 1×10 13 ions/cm 2 , resulting in an LDD structure. Although not shown, the device is complete-d by further forming a contact hole and the necessary wiring. If a SNOS structure (oxide film+nitride film) is employed as the gate insulating film 2, it is sufficient to oxidize the gate sidewall portion Furthermore, although the high concentration region 5 is formed prior to the formation of the low concentration region 4, these steps may be interchanged. An alternative form of the embodiment described above will be described in detail with respect to FIGS. 5A to 5C. Initially, as shown in FIG. 5A, a gate composed of the gate insulating film 2 and the polycrystalline silicon film 3 is formed on a p-type silicon substrate 1 in the same manner as shown in FIG. 4A, and then a low concentration source/drain region 4 is formed by injecting an n-type impurity (I) of low concentration under a low acceleration voltage while using the nitride film 21' as a mask. Thereafter, as shown in FIG. 5B, an oxide film 15 is formed on a sidewall of the gate while using the nitride film 21' as a mask, and then the high concentration region 5 is formed by injecting an n-type impurity (II) of high concentration with the nitride film 21' and the oxide film portion 15 on the gate sidewall as a mask. After the nitride film 14 and the oxide film 15 are removed, an LDD structure as shown in FIG. 5C is obtained. According to these embodiments, there is no need of removing the oxide film portion 15 on the gate side wall prior to ion injection, and thus there is no reduction of the thickness of the selective oxide film (SOF). As described above, the oxide film is formed on the gate sidewall using the insulating film on the gate as a mask, the high concentration region of the source/drain is formed by injecting impurity ions using the oxide film on the gate sidewall and the insulating film on the gate as a mask, and after the oxide film on the gate side wall is removed, the low concentration region of the source/drain is formed by injecting impurity ions. According to another embodiment of the invention though, the low concentration region is formed by injecting impurity ions using the insulating film on the gate as a mask, the oxide film is formed on the gate sidewall using the insulating film on the gate as a mask, and then the high concentration region is formed by injecting impurity ions using this oxide film and the insulating film on the gate as a mask. With this arrangement, the formation of the oxide film on the gate sidewall can be controlled easily. In this embodiment, the insulating film is formed on the gate electrode, which serves as an etching stopper for the anisotropic RIE of the conductive or polycrystalline semiconductor layer Therefore, the end point of etching can be detected accurately, and thus the width of the portion on the gate sidewall can be controlled precisely. FIGS. 6A to 6D illustrate main steps of this embodiment of the invention. Initially, as shown in FIG. 6A, a gate insulating film 2 and a polycrystalline gate electrode 3 are formed on a p-type silicon substrate 1. Then, an insulating film 40 is deposited thereon by low pressure CVD to a thickness of 300Å. After the gate electrode 3 and the insulating film 40 thereon are desirably shaped, an n-type region 4 is formed by injecting through the film 2, for example, phosphorous ions (P + ) at a density of 1×10 13 ions/cm 2 under an acceleration voltage of 60 KeV while using the shaped gate electrode 3 and the film 40 thereon as a mask. Then, as shown in FIG. 6B, a conductive layer 41, such as one made of polycrystalline silicon, is deposited by, for example, by LPCVD to a thickness of 4000Å. Thereafter, as shown in FIG. 6C, the conductive layer 41 is anisotropically etched using RIE while the light emission thereof is monitored to detect the end point of etching. Upon detection of the end point, the etching is terminated to leave a portion 41A of the conductive layer 41 on the sidewall of the gate unetched Then, after the insulating film 40 and the gate insulating film 2, which serve as etching stoppers, are removed, an n + type region 5 is formed by injecting arsenide ions (As + ) at a density of 4×10 15 ions/cm 2 under a 50 KeV acceleration voltage while using the gate electrode 3 and the conductive portion 41A as a mask, resulting in an LDD structure. Thereafter, as shown in FIG. 6D, a protective insulating film 11 and contact holes are formed and electrode wiring 12 is provided, resulting in a completed device. Although in the above-described embodiment an n-channel MOS field effect semiconductor device is described, the invention can be made applicable to the fabrication of a p-channel MOS field effect semiconductor device simply by using an n-type substrate and p-type impurity ions. Since the conductive layer portion on the gate sidewall is provided by forming the conductive layer on the insulating film on the gate electrode and anisotropically RIE etching it, the end point of etching can be detected easily, and the width of the conductive layer portion thus can be controlled precisely. In addition, the possibility of the etching away of the gate electrode is eliminated. It is further possible to set the width of the conductive layer portion at any value, causing the process itself to be simple, and thus making it possible to form an LDD structure in a well-controlled manner. FIGS. 7A to 7D illustrate main steps of a sixth embodiment of the invention. Initially, as shown in FIG. 7A, a gate electrode layer 50 composed of a gate oxide film 2 and a polycrystalline gate electrode 3 is formed on a p-type silicon substrate 1, and then an n - -type region 4 is formed by injecting, for example, phosphorous ions (P + ) at a density of 1×10 13 /cm 2 through the gate insulating film 2 under an acceleration voltage of 50 KeV while using the gate electrode 3 as a mask. Then, as shown in FIG. 7B, a high melting point metal such as tungsten is deposited thereon using, for example, a sputtering technique to form a tungsten layer 51 4000Å thick. Then, as shown in FIG. 7C, the tungsten layer 51, except a portion 52 thereof on the gate sidewall, is removed by anisotropic RIE, and a portion of the oxide film 2 exposed thereby is also removed. Thereafter, the n + -type region 5 is formed by injecting arsenide ions (As + ) at a density of 4×10 15 /cm 2 under an acceleration voltage of 50 KeV while using the gate electrode layer 50 and the tungsten portion 52 on the sidewall as a mask, resulting in an LDD structure. Then, as shown in FIG. 7D, a protective insulating film 11 is formed, in which desired contact holes are subsequently made. Upon forming electrode wiring 12, the device is completed. Although an n-channel MOS field effect semiconductor device has been described, the invention is also applicable to the fabrication of a p-type MOS field effect semiconductor device which utilizes an n-type substrate into which p-type impurities are injected. Further, instead of the high melting point metal, a silicide of such a metal may be used. According to this embodiment, since the gate sidewall portion is formed of a high melting point metal or a silicide of such a metal, it is possible to derive a portion of hot carriers through the gate electrode, and therefore a MOS field effect semiconductor device whose transconductance is not degraded by hot-carrier injection is obtained. FIGS. 8A to 8C illustrate main steps of a seventh embodiment of this invention. Initially, a gate electrode 50 composed-of a gate insulating film 2 and polycrystalline silicon 3 is formed on a silicon substrate 1, and then a low concentration n-type region 4 is formed by injecting, for example, p ions (I) at a rate of 1×10 13 ions/cm 2 through the gate insulating film 2 under an acceleration voltage of 50 KeV while using the gate electrode 50 as a mask (FIG. 8A). Then, a Pt layer 51 is deposited on the silicon substrate 1 to a thickness of 2000Å by sputtering (FIG. 8B). Thereafter, the substrate is heat-treated to silicide the polycrystalline silicon 3 (FIG. 8C) into a silicide region 52. The Pt layer 51 and the gate insulating film 2 are removed, and then after As (II) ion injection at 4×10 15 ions/cm 2 under an acceleration voltage of 50 KeV while using the silicide region 52 of the gate electrode as a mask, the substrate is heat-treated to form the high concentration n-type region 5, resulting in the LDD structure (FIG. 8D). Finally, a contact hole is formed in the region 5, and wiring is performed therethrough, resulting in a completed device (FIG. 8E). In this embodiment, the sidewall portion of the gate electrode also acts as the gate electrode so that hot carriers can be derived from the gate electrode, preventing the transconductance from being lowered. Also in this embodiment, the LDD structure includes the silicided gate electrode 52. Another embodiment in which both the gate electrode 20 and the source/drain are silicided will be described hereinafter. FIGS. 9A to 9E illustrate main steps of an eighth embodiment of the inventive method in which this is effected. The step shown in FIG. 9A is the same as in the case of FIG. 8A. After this step, a resist film 54 is formed on the silicon substrate 1, and a portion of the gate insulating film 2 and a desired region of the source/drain is removed using the resist film 54 as a mask (FIG. 9B). After the resist film 54 is removed, a high melting point metal 55 such as titanium is deposited to a thickness of 2000AÅ by sputtering. After the source/drain region is silicided to obtain silicided regions 60 and 70 (FIG. 9C), the high melting point metal (which is not silicided) and the gate insulating film 2 are removed. Thereafter, the high concentration region 5 of the source/drain is formed by injecting, for example, As at 4×10 15 ions/cm 2 under 50 KeV, resulting in an LDD structure (FIG. 9D). Thereafter, following heat treatment, contact holes are formed, and wiring is effected therethrough, resulting in a completed device (FIG. 9E). In this embodiment, it is possible, in addition to the effects obtained in the above-described embodiments, to reduce the sheet resistance of the source/drain region in which the metal is silicided. However, if the high melting point metal 55 around the source/drain area and the gate electrode is silicided by heat treatment for a considerable time, the metal can become over-silicided, causing a short-circuit between the gate electrode and the source/drain. FIGS. 10A to 10E illustrate main steps of another embodiment of the invention in which this problem is eliminated. FIG. 10A is the same as the FIG. 9A. After this step, a resist film 54 is formed on the silicon substrate 1, and, while using the resist film 54 as a mask, a portion of the gate insulating film 2 in a desired region of the source-drain is removed. Then, As (III) is injected at a rate of 4×10 15 ions/cm 2 under 30 KeV (FIG. 10B). After the resist film 54 is removed, a high melting point metal 55 such as molybdenum is deposited by sputtering to thickness of 2000Å. Thereafter, a heat treatment is performed. Since the impurity concentration of the source/drain region to be silicided is high, the silicidation reaction rate is reduced in the heat treatment, and hence the resulting silicide does not cause a short-circuit between the gate electrode and the source/drain (FIG. 10C). Thereafter, the molybdenum layer 55 (which is not silicided) is removed, and As (II) is injected at 4×10 15 ions/cm 2 under 50 KeV to obtain an LDD structure (FIG. 10D). Finally, the substrate is heat-treated, and, after wiring through contact holes, the device is completed (FIG. 10E). In this embodiment, the high melting point metal is deposited by sputtering. Therefore, because the metal is deposited unavoidably over the entire surface of the silicon substrate, the portion thereof not silicided has to be removed in a separate step. FIGS. 11A to 11F illustrate main steps of an embodiment in which the removal step of the high melting point metal is eliminated. FIGS. 11A and 11B are the same as FIGS. 9A and 9B, respectively. After the step shown in FIG. 11B, the resist film 54 is removed, and then a tungsten silicide layer is formed preferably on the source/drain region, except a portion hereof beneath the gate insulating film and on the gate electrode, by LPCVD deposition of tungsten (FIG. 11C). Thereafter, the gate insulating film is removed, and then As (II) is injected at 4×10 15 ions/cm 2 under 50 KeV, resulting in a LDD structure (FIG. 11D). Then, a heat treatment is performed (FIG. 11E) and a contact hole is formed. After wiring, the device is completed (FIG. 11E). Thus, according to this embodiment, the step of removing the portion of the high melting point metal which is not silicided becomes unnecessary. Although n-channel insulated gate (MOS) semiconductor devices are described with reference to the above embodiments, the invention can also be made applicable to the manufacture of p-channel insulated gated (MOS) field effect semiconductor devices by using an n-type substrate and injecting a p-type impurity thereinto. According to the inventive method, the gate sidewall portion and/or the source/drain region is silicided. Therefore, because the sidewall portion acts as a portion of the gate electrode through which hot carriers are derived, a reduction of the transconductance of the device is prevented, and the sheet resistance of the source/drain region (which is silicided) is reduced. FIGS. 12A to 12D illustrate main steps of still another embodiment of the invention. As shown in FIG. 12A, a gate electrode 20 is formed on a p-type silicon substrate 1. Then, a low concentration n-type region 4 is formed by injecting, for example, P + ions (I) at 1×10 14 ions/cm 2 under an acceleration voltage of 30 KeV while using the gate electrode 20 as a mask. Thereafter, as shown in FIG. 12B, the region 4 is made amorphous by injecting silicon ions (III) at about 1×10 15 ions/cm 2 under an acceleration voltage of 30 KeV to obtain an amorphous region 61. Then, as shown in FIG. 12C, an oxide film 19 is deposited by LPCVD. Thereafter, as shown in FIG. 12D, the oxide film 19, except a portion 19' thereof on a side wall of the gate electrode 20, is removed by anisotropic etching. Then, a high concentration n-type region 5 is formed by injecting, for example, As + ions at 4×10 15 ions/cm 2 under 50 KeV while using the gate electrode 20 and the oxide film portion 19' as a mask, resulting in a LDD structure. Then, the source/drain region is activated by a low temperature annealing process such as rapid annealing, and, after contact holes are made and wiring therethrough effected, the device is completed. Although in the above embodiment the present invention has been described with respect to and n-channel insulated gate (MOS) field effect semiconductor device, the invention is applicable also to a p-channel insulated gate (MOS) field effect semiconductor device using an n-type substrate and p-type impurity ions. Although the source/drain region in the above embodiment is made amorphous by silicon ion injection, it is possible to use instead of silicon ions an inert gas ion such as He, Ne, Ar, Kr, Xe or Rn. According to this embodiment, because the low concentration n-type source-drain region is made amorphous by ion injection of silicon inert gas, crystallization can be restored by rapid annealing or low temperature annealing, and thus shallow injection can be realized easily, which is effective in minimizing the size of the device.

A method of fabricating a MOS field effect semiconductor device having an LLD structure is described in which an insulating film is formed on a gate electrode and a layer of polycrystalline silicon, oxide, high melting point metal or a silicide of a high melting point metal is formed on a wafer and etched away by anisotropic RIE, except a portion thereof on a sidewall of the gate. With the resulting structure, degradation of the transconductance of the device due to injection of hot carriers is prevented. Also, the size of the device can be minimized without unduly increasing the resistances of the drain/source region, the gate electrode, and the contacts of the device.

big_patent

BACKGROUND OF THE INVENTION The present invention relates to Internet telephony, and more particularly to an improved end-user interface for Internet-protocol (IP) telephone communication. Today, Internet telephony is an emerging competitor to conventional telephony as long distance calls are carried over the global Internet at relatively low cost. Additionally, although present Internet telephony systems provide comparably poor quality of service, future improvements will undoubtedly provide signal quality at least on the order of that provided by conventional systems. Available IP telephones consist primarily of a multimedia personal computer (PC) running a software telephony application which translates end-user sound signals into appropriately formatted digital signals for transfer over a computer network (e.g., the global Internet), and vice versa. Typically, such a multimedia PC includes a sound card with a microphone and a speaker for speech input and output, and accesses the computer network through an appropriate network interface, such as a public switched telephone network (PSTN), a wireless network, or a public or private data network. The software telephony application compresses and decompresses end-user speech signals in order to decrease bandwidth requirements for computer network transmissions. Thus, speech coding and decoding is typically carried out by a central processing unit (CPU) in the multimedia PC. The precise type of speech coding used (e.g., GSM, D-AMPS, etc.) depends upon the bit-rate and speech quality requirements for a given application. Compressed sound signals are transmitted over the computer network using an appropriate UDP/IP network protocol, as is well known in the art. As with speech coding and decoding, the computer network protocol is conventionally administered by the software telephony application running on the multimedia PC. Despite the above described benefits, the IP telephone of today has several disadvantages as compared to a conventional telephone. For example, common speech coding and decoding algorithms require high performance PCs including relatively fast CPUs. Additionally, the conventional IP-telephone application requires extra sound equipment, such as a sound card and microphone, which is not often included in a standard consumer PC package. Thus, the conventional IP telephone consists of a relatively high-end PC which is high-priced, power-hungry, and over-sized as compared to a conventional telephone. Additionally, the PC is normally switched off and requires a relatively long and inconvenient boot-up time. Furthermore, even a fully equipped PC does not normally include a comfortable end-user telephone handset, and the relative distance between the PC microphone and PC speaker can cause disturbing echoes for system users. Thus, there is a real need for an improved IP telephone. SUMMARY OF THE INVENTION The present invention fulfills the above described and other needs by providing an enhanced radio telephone which can be connected to a PC and used as a significantly improved IP telephone. By way of contrast to an ordinary radio telephone in which a speech coder digital interface is connected exclusively to radio circuitry for wireless communication (e.g., via a cellular radio system), the enhanced radio telephone can transmit and receive digitized and coded speech signals via an alternate external connection as well. Thus, the enhanced radio telephone can selectively operate as either a conventional radio telephone or as an improved IP telephone. Advantageously, the enhanced radio telephone includes an internal speech coder which is implemented for low power consumption and which allows the enhanced radio telephone to be used with a relatively low-performance PC for effective IP telephony. The enhanced radio telephone thereby provides a low cost IP telephone solution in which speech delay is reduced as compared to conventional IP telephone systems. Additionally, the enhanced radio telephone handset is convenient for speech conversation and reduces the above described echo problems which are commonly associated with conventional IP telephones. In exemplary embodiments, the enhanced radio handset is connected via a cable to a serial or parallel port of a PC running a streamlined software telephony application. In alternative embodiments, a wireless infrared (IR) or short range radio connection is used for communication between the enhanced radio telephone and the PC. Coded and compressed digital speech signals are passed back and forth between the enhanced radio telephone and the PC, and the PC performs conversions between the coded speech signals and an appropriate computer network protocol. Because the PC need not perform speech coding and decoding, the PC may be implemented, for example, as a low-end desk-top computer, a lap-top/notebook computer, or even a palm-top computer. Advantageously, a standard PC serial or parallel port connection is sufficient to carry digital speech and control signalling in both directions between the enhanced radio telephone and the PC. According to the invention, IP-telephone control is initiated from either the PC or the enhanced radio telephone. Additionally, the enhanced radio telephone is switched between ordinary wireless (e.g., cellular) operation and IP-telephone operation either manually (e.g., via a pushbutton on the radio handset) or automatically from the PC (e.g., via an option in the telephony application running on the PC). Furthermore, a call can be initiated using either the PC software telephony application or a keypad on the enhanced radio telephone. In alternative embodiments, the enhanced radio telephone is also used for wireless data communication in order to carry IP speech. In other words, coded speech is passed from the enhanced radio telephone to the PC where it is formatted according to an appropriate UDP/IP network protocol, and the resulting IP speech is passed back to the enhanced radio telephone for transmission to a computer network via a wireless network interface. In such an exemplary embodiment, IP data transfer is conducted using either a separate connection on the enhanced radio telephone or the same connection which is used to carry coded speech and control signalling. Advantageously, a PC serial port is sufficient to carry digital speech, control signalling and IP data. In brief, the present invention provides an improved IP telephone which is more convenient, economical and efficient as compared to conventional IP telephony systems. These and additional features of the present invention are explained in greater detail hereinafter with reference to the illustrative examples which are shown in the accompanying drawings. Those skilled in the art will appreciate that the described embodiments are provided for purposes of illustration and understanding and that numerous equivalent embodiments are contemplated herein. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a prior art IP telephony system. FIG. 2 is a block diagram of an IP telephony system constructed in accordance with the teachings of the present invention. FIGS. 3 and 4 are block diagrams of alternative IP telephony systems constructed in accordance with the teachings of the present invention. DETAILED DESCRIPTION OF THE INVENTION FIG. 1 depicts a prior art IP telephony system 100. As shown, the conventional system 100 includes a high-performance PC 110 and a network interface 120. The high-performance PC 110 includes a speaker 105, a sound card 125, a microphone 115, a CPU 135, and an input/output port 145. In the figure, an output of the microphone 115 is coupled to an input of the sound card 125, and an output of the sound card 125 is coupled to an input of the speaker 105. An input/output port of the sound card 125 is coupled to a first input/output port of the CPU 135, and a second input/output port of the CPU 135 is coupled to the PC input/output port 145. The PC input/output port 145 is in turn coupled to a first input/output port of the network interface 120, and a second input/output port of the network interface 120 is coupled to a network 130. The network 130 may be, for example, the global Internet or an Intranet operated by a public or private organization. Thus, the term "IP" will be understood to encompass both Internet-protocol and Intranet-protocol systems. In operation, a near-end user of the PC 110 initiates an IP telephone call, for example by activating a software telephony application on the PC 110. During conversation, the near-end user speaks into the microphone 115, and the audio signal received by the microphone 115 is digitized within the sound card 125. The digitized signal which is output by the sound card 125 is passed to the CPU 135. The CPU 135, which is running the telephony application, compresses and codes the digitized speech using an appropriate speech coding algorithm (e.g., GSM, D-AMPS, etc.) and converts the coded speech, using an appropriate UDP/IP network protocol, into a format which is appropriate for transmission via the network 130. The resulting IP data is transmitted by the CPU 135 via the PC input/output port 145 to the network interface 120, where it is routed to the network 130 and passed on to a far-end user. Conversely, IP speech signals generated by the far-end user are received from the network 130 at the network interface 120 and passed to the PC 110 via the PC input/output port 145. The CPU 135 receives the IP-formatted far-end data and converts it to corresponding coded far-end speech signals. The coded far-end speech signals are decoded by the CPU 135 using an appropriate algorithm to produce digital sound data which is passed to the sound card 125. The sound card 125 converts the digital far-end sound data into a corresponding analog signal which is directed to the speaker 105 for presentation to the near-end user. As is well known in the art, the network interface 120 may connect to any one of a number of available systems in order to access the network 130. For example, the network interface 120 may connect to a public switched telephone network (PSTN), a wireless radio system, or a public or private data network as appropriate. Accordingly, the link between the PC 110 and the network interface 120 can utilize any appropriate digital protocol, depending upon the particular type of link used in a given application. When the link is an analog PSTN, the network interface 120 converts digital coded information received from the PC 110 into analog signals suitable for transmission over conventional telephone lines using a conventional modem. When the link is a digital telephone network, the network interface 120 converts digital information received from the PC 110 into a digital protocol associated with the telephone network (e.g., ISDN). When the link is a wireless radio system, the network interface 120 includes a suitable transceiver for modulating and demodulating signals transmitted to, and received from, the network interface 120, respectively. When the link is a public or private data network, the network interface 120 converts digital coded information received from the PC 110 into a format which is appropriate for the public or private network. Advantageously, the network interface 120 can be integrated into the PC 110 or even the CPU 135. Though the system of FIG. 1 is sufficient for certain applications, it suffers from several significant disadvantages as described above. For instance, advanced speech coding and decoding algorithms, necessary for reduced delay and signal quality, require that the CPU 135 be relatively fast. Additionally, the sound card 125 and the microphone 115 are accessories not typically included in a standard consumer PC package. Furthermore, the relatively complex software telephony application, which must perform both speech coding/decoding and UDP/IP conversion, may be prohibitively expensive and require significant computer memory. Advantageously, the present invention teaches that a radio telephone, ordinarily used exclusively for wireless radio (e.g., cellular) communication, can be enhanced to work in conjunction with a PC-based telephony application so that computationally intensive speech coding and decoding can be performed external to the PC and so that an effective IP telephone can be constructed economically without requiring a high-end computer. FIG. 2 is a conceptual diagram of an IP telephony system 200 constructed in accordance with the teachings of the present invention. As shown, the improved IP telephony system 200 includes an enhanced wireless telephone 250, a PC 210 and a network interface 120. The enhanced wireless telephone 250 includes a speaker 205 (e.g., an earphone in a wireless handset), a speech decompressor 225, an antenna 255, a radio frequency transceiver 265, a digital interface 275, an external connection 245, a speech compressor 235 and a microphone 215 (e.g., within a mouthpiece in a wireless handset). As shown, an output of the microphone 215 is coupled to an input of the speech compressor 235, and an output of the speech compressor 235 is coupled to an input of the digital interface 275. Additionally, an output of the digital interface 275 is coupled to an input of the speech decompressor 225, and an output of the speech decompressor 225 is coupled to an input of the speaker 205. The antenna 255 is bi-directionally coupled to the RF transceiver 265 which is in turn bi-directionally coupled to a first input/output port of the digital interface 275. A second input/output port of the digital interface 275 is coupled to the external connection 245, and the external connection 245 is in turn coupled to a first input/output port of the PC 210. A second input/output port of the PC 210 is coupled to a first input/output port of the network interface 120, and a second input/output port of the network interface 120 is coupled to a network 130 such as the global Internet or an Intranet. In a first, wireless-telephone mode of operation, the digital interface 275 directs output from the speech coder 235 to the radio frequency transceiver 265, and directs output from the radio frequency transceiver 265 to the speech decoder 225, so that the enhanced radio telephone 250 operates as a conventional wireless telephone. In other words, speech signals from the near-end user received at the microphone 215 are compressed and coded by the speech coder 235 and transmitted by the radio frequency transceiver 265 to a wireless (e.g., cellular) system via the antenna 255. Conversely, far-end radio signals received from the wireless system by the radio frequency transceiver 265 are decoded by the speech decoder 225 and presented to the near-end user via the speaker 205. In a second, IP-telephone mode of operation, the digital interface 275 directs output from the speech coder 235 to the external connection 245, and directs output from the external connection 245 to the speech decoder 225, so that the enhanced radio telephone 250 operates in conjunction with the PC 210 as an improved IP telephone. In other words, coded speech signals are passed from the speech coder 235 to the PC 210 where they are formatted by a software telephony application using an appropriate UDP/IP network protocol. The network-formatted signals are transmitted by the PC 210 to the network 130 via the network interface 120 as described above with reference to FIG. 1. Conversely, network-formatted far-end signals received at the PC 210 via the network interface 120 are converted by the PC telephony application into corresponding coded far-end speech signals. The coded far-end speech signals are passed to the speech decoder 225 where they are decoded and presented to the near-end user via the speaker 205. As above, the network interface 120 may connect to any one of a number of available network links, including a PSTN, a wireless radio system, or a public or private data network. Advantageously, the network interface 120 can be integrated within the PC 210. The speech coder 235 and the speech decoder 225, respectively, code and decode speech during IP-telephone operation using the same algorithms (e.g., GSM, D-AMPS, etc.) used during radio-telephone operation. Advantageously, the speech coder 235 and the speech decoder 225 are constructed in accordance with the radio telephone art to operate at high speed using relatively little power. Because the burden of speech coding and decoding is removed from the telephony application running on the PC 210, the telephony application can be streamlined, and the CPU within the PC 210 need not be nearly as fast as that of the PC 110 of the system of FIG. 1. Additionally, the PC 210 need not include a sound card, a microphone, or a speaker. As a result, the PC 210 can be implemented using a relatively inexpensive, relatively low-performance computer. Additionally, the enhanced radio telephone 250 provides a convenient and comfortable handset for the near-end user and significantly reduces the echo problem associated with conventional IP telephones. For example, because the near-end user holds the handset to his or her ear, the echo path between the microphone and the speaker is largely blocked. Furthermore, the enhanced radio telephone 250 can provide echo canceling circuitry as is well known in the radio telephone art. In the embodiment of FIG. 2, coupling between the external connection 245 and the PC 210 is implemented using a standard serial or parallel PC cable connection. Alternatively, the connection can be established using well known IR or shortwave radio techniques. Coded speech and control information is exchanged between the enhanced radio telephone 250 and the PC 210 using handshaking techniques which are well known in the art. The enhanced radio telephone 250 and the PC 210 are programmed so that IP-telephone operation can be controlled from either the PC 210 or the enhanced radio telephone 250. Switching between IP-telephone operation and wireless-telephone operation can be initiated manually using a keypad on the enhanced radio telephone 250 or automatically via the telephony application running on the PC 210. Additionally, a user of the enhanced radio telephone 250 can initiate a call using either the enhanced radio telephone keypad or the telephony application on the PC. Thus, the embodiment of FIG. 2 provides an improved IP telephone which is more convenient, economical and efficient than conventional IP telephones. FIG. 3 is a conceptual diagram of an alternative IP telephony system 300 constructed in accordance with the teachings of the present invention. As shown, the IP telephony system 300 includes an enhanced wireless telephone 350, a PC 310 and a network interface 120. The enhanced wireless telephone 350 includes a speaker 205, a speech decompressor 225, an antenna 255, a radio frequency transceiver 265, a digital interface 275, first and second external connections 345, 346, a speech compressor 235 and a microphone 215. As shown, an output of the microphone 215 is coupled to an input of the speech compressor 235, and an output of the speech compressor 235 is coupled to an input of the digital interface 275. Additionally, an output of the digital interface 275 is coupled to an input of the speech decompressor 225, and an output of the speech decompressor 225 is coupled to an input of the speaker 205. The antenna 255 is bi-directionally coupled to the RF transceiver 265 which is in turn bi-directionally coupled to a first input/output port of the digital interface 275. A second input/output port of the digital interface 275 is coupled to each of the external connections 345, 346. The first external connection 345 is coupled to an input/output port of the PC 310, and the second external connection 346 is coupled to a first input/output port of the network interface 120. A second input/output port of the network interface 120 is coupled to a network 130 such as the global Internet or an Intranet. In general, operation of the exemplary embodiment of FIG. 3 is similar to that of FIG. 2. For example, in a first, wireless-telephone mode of operation, the digital interface 275 directs output from the speech coder 235 to the radio frequency transceiver 265, and directs output from the radio frequency transceiver 265 to the speech decoder 225, so that the enhanced radio telephone 250 operates as a conventional wireless telephone. However, during an IP-telephone mode of operation, the PC 310 is used to convert between coded speech data and network-formatted data, and the enhanced radio telephone 350 is used to exchange network-formatted data with the network 130 via the network interface 120. During IP-telephone operation, coded speech signals are passed from the speech coder 235 to the PC 310 where they are formatted by a software telephony application using an appropriate UDP/IP network protocol. Thereafter, the network-formatted signals are directed back from the PC 310 to the enhanced radio telephone 350 and transmitted to the network 130 via the network interface 120. Conversely, network-formatted far-end signals received at the enhanced radio telephone 350 via the network interface 120 are passed to the PC 310 and converted by the telephony application into corresponding coded far-end speech signals. The coded far-end speech signals are passed back to the enhanced radio telephone 350 and then to the speech decoder 225 where they are decoded and presented to the near-end user via the speaker 205. As described above with respect to FIGS. 1 and 2, the network interface 120 may connect to any one of a number of available network links, including a PSTN, a wireless radio system, or a public or private data network. Advantageously, the network interface 120 may be integrated within the enhanced radio telephone 350. When the link is a PSTN, the network interface 120 may comprise a modem or an ISDN line. When the link is a public or private data network, the network interface 120 comprises an appropriate digital connection (e.g., an Ethernet connection). When the link is a wireless radio system, the network interface 120 comprises a suitable transceiver for modulating and demodulating network-formatted signals as necessary. Advantageously, the RF transceiver 265 can be adapted to provide appropriate wireless communication during both the wireless-telephone mode of operation and the IP-telephone mode of operation. In other words, the operating frequencies of the RF transceiver 265 can be tuned as necessary to communicate with different systems. The embodiment of FIG. 3 provides advantages similar to those described above with respect to the embodiment of FIG. 2. Additionally, because the task of communicating with the network 130 is shifted to the enhanced radio telephone 350, the PC 310 (and the telephony application running on the PC 310) can be streamlined still further. Thus, like the embodiment of FIG. 2, the exemplary embodiment of FIG. 3 provides an improved IP telephone which is more convenient, economical and efficient than conventional IP telephones. FIG. 4 is a conceptual diagram of another alternative IP telephony system 400 constructed in accordance with the teachings of the present invention. As shown, the IP telephony system 400 includes an enhanced wireless telephone 450 and a network interface 120. The enhanced wireless telephone 450 includes a speaker 205, a speech decompressor 225, an antenna 255, a radio frequency transceiver 265, a digital interface 275, a network converter 410, an external connection 445, a speech compressor 235 and a microphone 215. As shown, an output of the microphone 215 is coupled to an input of the speech compressor 235, and an output of the speech compressor 235 is coupled to an input of the digital interface 275. Additionally, an output of the digital interface 275 is coupled to an input of the speech decompressor 225, and an output of the speech decompressor 225 is coupled to an input of the speaker 205. The antenna 255 is bi-directionally coupled to the RF transceiver 265 which is in turn bi-directionally coupled to a first input/output port of the digital interface 275. A second input/output port of the digital interface 275 is coupled to a first input/output port of the network converter 410, and a second input/output port of the network converter 410 is coupled to the external connection 445. Additionally, the external connection 445 is coupled to a first input/output port of the network interface 120, and a second input/output port of the network interface 120 is coupled to a network 130 such as the global Internet or an Intranet. In general, operation of the exemplary embodiment of FIG. 4 is similar to operation of the embodiments of FIGS. 2 and 3. For example, in a first, wireless-telephone mode of operation, the digital interface 275 directs output from the speech coder 235 to the radio frequency transceiver 265, and directs output from the radio frequency transceiver 265 to the speech decoder 225, so that the enhanced radio telephone 450 operates as a conventional wireless telephone. However, during an IP-telephone mode of operation, the internal network converter 410 converts between coded speech data and network-formatted data, and therefore an external PC is not necessary. During IP-telephone operation, coded speech signals are passed from the speech coder 235 to the network converter 410 where they are formatted using an appropriate UDP/IP network protocol. Thereafter, the network-formatted signals are directed to the network 130 via the network interface 120. Conversely, network-formatted far-end signals received at the enhanced radio telephone 350 via the network interface 120 are converted by network converter 410 into corresponding coded far-end speech signals. The coded far-end speech signals are passed through the digital interface 275 to the speech decoder 225 where they are decoded and presented to the near-end user via the speaker 205. As described above with respect to FIGS. 1-3, the network interface 120 may connect to any one of a number of available network links, including a PSTN, a wireless radio system, or a public or private data network. Advantageously, the network interface 120 may be integrated within the enhanced radio telephone 350. When the link is a PSTN, the network interface 120 may comprise a modem or an ISDN line. When the link is a public or private data network, the network interface 120 comprises an appropriate digital connection (e.g., an Ethernet connection). When the link is a wireless radio system, the network interface 120 comprises a suitable transceiver for modulating and demodulating network-formatted signals as necessary. As above, the RF transceiver 265 can be adapted to provide appropriate wireless communication during both the wireless-telephone mode of operation and the IP-telephone mode of operation. In other words, the operating frequencies of the RF transceiver 265 can be tuned as necessary to communicate with different systems. The embodiment of FIG. 4 provides advantages similar to those described above with respect to the embodiments of FIGS. 2 and 3. Additionally, because the task of converting between IP signals and coded speech signals is integrated into the enhanced radio telephone 450, the need for an external PC is eliminated. Thus, like the embodiments of FIGS. 2 and 3, the exemplary embodiment of FIG. 4 provides an improved IP telephone which is more convenient, economical and efficient than conventional IP telephones. In practice, any one of the embodiments of FIGS. 2-4 can be utilized to advantage, depending upon the cost and performance requirements of a given application. Those skilled in the art will appreciate that the present invention is not limited to the specific exemplary embodiments which have been described herein for purposes of illustration. The scope of the invention, therefore, is defined by the claims which are appended hereto, rather than the foregoing description, and all equivalents which are consistent with the meaning of the claims are intended to be embraced therein.

An enhanced radio telephone providing both wireless communication and Internet-protocol (IP) telephone communication. In addition to transmitting and receiving digitized and coded speech signals in a wireless fashion using a radio transceiver, the enhanced radio telephone can also exchange coded speech data with a computer which is coupled to a communication network. Thus, the enhanced radio telephone can selectively operate as either a conventional radio telephone or as an improved IP telephone. The enhanced radio telephone includes an internal speech coder which is implemented for low power consumption and which allows the enhanced radio telephone to be used with a relatively low-cost computer for effective and economic IP telephony. In exemplary embodiments, an enhanced radio handset is connected to an input/output port of a personal computer running a software telephony application. Coded and compressed digital speech signals are passed back and forth between the enhanced radio telephone and the computer, and the computer performs conversions between the coded speech signals and an appropriate network protocol. Because the computer does not perform speech coding and decoding internally, the computer functionality may be implemented, for example, using an inexpensive notebook or palm-top computer. Advantageously, a user may initiate telephone calls from either the enhanced radio telephone or the telephony application running on the computer.

big_patent

FIELD OF INVENTION [0001] This invention relates to devices for producing electrical power, pressurized water or other useful work from surface waves on a water body. [0002] More particularly, this invention relates to wave energy converters wherein either all or a substantial portion of the energy captured or produced is from one or more submerged devices relying on overhead wave induced subsurface differences in hydrostatic pressure and/or enhanced surge or pitch which expand and contract or otherwise deform or deflect one or more gas filled submerged containers, thereby producing useful work. Such expansion and contraction is enhanced or supplemented by wave focusing, reflection or diffraction techniques and/or by overhead surface floating bodies. BACKGROUND OF THE INVENTION [0003] Wave energy commercialization lags well behind wind energy despite the fact that water is several hundred times denser than air and waves remain for days and even weeks after the wind which originally produced them has subsided. Waves, therefore, efficiently store wind kinetic energy at much higher energy densities, typically averaging up to 50 to 100 kw/m of wave front in many northern latitudes. [0004] Hundreds of uniquely different ocean wave energy converters (OWECs) have been proposed over the last century and are described in the patent and commercial literature. Less than a dozen OWEC designs are currently deployed as “commercial proto-types.” Virtually all of these suffer from high cost per average unit of energy capture. This is primarily due to the use of heavy steel construction necessary for severe sea-state survivability combined with (and in part causing) low wave energy capture efficiency. Only about 10% of currently proposed OWEC designs are deployed subsurface where severe sea-state problems are substantially reduced. Most subsurface OWECs are, unfortunately, designed for near shore sea bed deployment. Ocean waves lose substantial energy as they approach shore (due to breaking or reflected wave and bottom and hydrodynamic friction effects). Near shore submerged sea bed OWECs must be deployed at greater depths relative to average wave trough depths due to severe sea-state considerations to avoid breaking wave turbulence, and depth can not be adjusted for the large tidal depth variations found at the higher latitudes where average annual wave heights are greatest. Wave induced subsurface static pressure oscillations diminish more rapidly in shallow water as the depth below waves or swell troughs increases. [0005] Only a few prior art subsurface devices use gas filled or evacuated containers like the present invention, producing container deformation in response to overhead swell and trough induced static pressure changes. None of the prior art subsurface OWECs capture both hydrostatic (heave) and hydrokinetic wave energy (surge or pitch) which represents half of all wave energy. None of these prior art subsurface OWECs enhance or supplement energy capture with overhead floating bodies. All of the prior subsurface deformable container OWECs suffer from high mass (and therefore cost) and low energy capture efficiency (even more cost) usually due to near shore or sea bed deployment and high mass. None of these have the tidal and sea-state depth adjustability of the present invention needed for enhanced energy capture efficiency and severe sea-state survivability. None have the low moving mass (allowing both short wave and long swell energy capture) and the large deformation stroke (relative to wave height) needed for high capture efficiency of the present invention. [0006] At least two prior art devices use two variable volume gas filled containers, working in tandem, to drive a hydraulic turbine or motor. Gardner (U.S. Pat. No. 5,909,060) describes two sea bed deployed gas filled submerged inverted cup shaped open bottom containers laterally spaced at the expected average wavelength. The inverted cups are rigidly attached to each other at the tops by a duct. The cups rise and fall as overhead waves create static pressure differences, alternately increasing and decreasing the gas volume and hence buoyancy in each. The rise of one container and concurrent fall of the other (called an “Archemedes Wave Swing”) is converted into hydraulic work by pumps driven by said swing. [0007] Similarly, Van Den Berg (WO/1997/037123 and FIG. 1 ) uses two sea bed deployed submerged average wavelength spaced interconnected pistons, sealed to underlying gas filled cylinders by diaphragms. Submerged gas filled accumulators connected to each cylinder allow greater piston travel and hence work. The reciprocating pistons respond to overhead wave induced hydrostatic pressure differences producing pressurized hydraulic fluid flow for hydraulic turbines or motors. [0008] The twin vessel Archemedes Wave Swing (“AWS”) of Gardner (U.S. Pat. No. 5,909,060) later evolved into a single open bottomed vessel ( FIG. 2 ) and then more recently Gardner's licensee, AWS Ocean Energy has disclosed an enclosed gas filled vessel (an inverted rigid massive steel cup sliding over a second upright steel cup) under partial vacuum ( FIG. 3 ). Partial vacuum, allowing increased stroke, is maintained via an undisclosed proprietary “flexible rolling membrane seal” between the two concentric cups. Power is produced by a linear generator ( FIG. 2 shown) or hydraulic pump driven by the rigid inverted moving upper cup. An elaborate external frame with rails and rollers, subject to fouling from ocean debris, is required to maintain concentricity and preserve the fragile membrane. [0009] FIG. 4 (Burns U.S. 2008/0019847A1) shows a submerged sea bed mounted gas filled rigid cylindrical container with a rigid circular disc top connected by a small diaphragm seal. The disc top goes up and down in a very short stroke in response to overhead wave induced static pressure changes and drives a hydraulic pump via stroke reducing, force increasing actuation levers. Burns recognizes the stroke and efficiency limitations of using wave induced hydrostatic pressure variations to compress a gas in a submerged container and attempts to overcome same by arranging multiple gas interconnected containers perpendicular to oncoming wave fronts. North (U.S. Pat. No. 6,700,217) describes a similar device. Both are sea bed and near shore mounted and neither is evacuated or surface vented like the present invention to increase stroke and, therefore, efficiency. [0010] FIG. 5 (Meyerand U.S. Pat. No. 4,630,440) uses a pressurized gas filled device which expands and contracts an unreinforced bladder within a fixed volume sea bed deployed rigid container in response to overhead wave induced static pressure changes. Bladder expansion and contraction within the container displaces sea water through a container opening driving a hydraulic turbine as sea water enters and exits the container. Expansion and contraction of the submerged bladder is enhanced via an above surface (shore mounted) diaphragm or bellows. High gas pressure is required to reinflate the submerged bladder against hydrostatic pressure. DISCLOSURE OF THE PRESENT INVENTION [0011] According to embodiments of the present invention, one or more gas tight containers are submerged to a depth slightly below anticipated wave and swell troughs. The container(s) have a fixed depth rigid end or surface held at relatively fixed depth relative to the water body mean water level or wave troughs by either a flexible anchoring means, with horizontal depth stabilization discs or drag plates, or by a rigid sea bed attached spar or mast, or the bottom itself. A second movable rigid end or surface opposes said first fixed end or surface. Said fixed and movable ends are separated and connected by and sealed to a flexible, gas tight, reinforced, elastomer or flexible metal bellows, or a diaphragm or accordion pleated skirt also suitably reinforced against collapse from container internal vacuum or external hydrostatic pressure. Overhead waves and troughs produce hydrostatic pressure variations which compress and expand said containers, respectively, bringing said movable end closer to and further from said fixed depth end. Container expansion and contraction (or “stroke”) is enhanced by either partial evacuation of said container or venting of said containers' gas to a floating surface atmospheric vent or to a floating surface expandable bellows or bladder, or reservoir. Without said partial evacuation or atmospheric venting, said stroke and hence energy capture would be reduced several fold. The relative linear motion between said containers' fixed and movable ends is connected to and transferred to a hydraulic or pneumatic pumping means or, mechanical or electrical drive means. The pressurized fluid flow from said hydraulic or pneumatic pumping can drive a motor or turbine with electric generator. Mechanical means can direct drive a generator via rack and pinion gearing, oscillating helical drive or other oscillating linear one or two way rotational motion means. Electrical drive means can be by a linear generator. After compression return and expansion of said containers and its' movable end can be assisted by mechanical (i.e. springs) pneumatic (compressed gas), hydraulic or electric means. Efficiency can be further enhanced by delaying said compression and expansion until hydrostatic pressure is maximized and minimized, respectively via the use of pressure sensors and control valves. Power recovery can occur on either or both strokes. The submerged depth of said containers relative to the sea bed and wave troughs can be hydrostatically sensed and adjusted by a hydrostatic bellows or by hydraulic or electro-mechanical drives for tides to maintain high efficiency by maintaining a relatively shallow submerged depth. The submerged depth can also be increased or the device can be temporarily compressed or locked down during severe sea-states to increase survivability. The stroke or linear motion produced by said container's compression and expansion and applied to said pumping or drive means can be reduced and its' drive force correspondingly increased by use of leveraged connecting means such as rack and pinion or reduction gears, scissor-jacks, linear helical drivers, or lever and fulcrum actuators. High hydraulic pressure can be produced even in moderate sea states by the sequential use of multiple drive cylinders of different sectional areas or by using multi-stage telescoping cylinders. The linear oscillating motion of said container(s) expansion and contraction can be converted into smooth one way turbine, pump, motor or generator rotation via the use of known methods including accumulator tanks, flow check (one way) valves and circuits or mechanical drives, ratchets and flywheels. Mechanically connecting said moving second surface to any floating overhead device, including said floating vent buoy or a floating wave energy converter further increases stroke, energy capture and efficiency. Suitably shaping, inclining (towards wave fronts) and extending the surfaces of said moving second surface provides major additional energy capture. Wave reflection (off a back wall) and focusing also increase both potential (heave) and kinetic (surge and pitch) wave energy capture. The subject device may have a typical diameter and stroke of 5-10 meters and produce 0.25 MW to 1 MW of electrical power. Elongated or multi-unit devices may have major dimensions and outputs of several times that. Distinguishing Features Over Prior Art [0012] The subject invention provides substantial advantages over the prior art. Van Den Berg (WO/1997/037123), shown in FIG. 1 , requires two shallow water sea bed mounted pistons rather than the one of the present invention, separated by an average wavelength. A gas tight chamber is maintained below each piston by a rolling membrane seal. The rolling membrane seal limits stroke and, therefore, energy capture and is vulnerable to frictional wear between the piston and cylinder and near shore debris caught within the seal. The two chambers are connected to two gas accumulator tanks to slightly increase piston travel and rebound rather than utilize the partial evacuation or surface or atmospheric venting of the present invention. The piston connecting rods drive hydraulic pumps which drive a hydraulic motor and generator. Twin chamber devices spaced one average wavelength apart are inherently inefficient as wavelengths are very seldom at their average value. At 0.5 or 1.5 times average wavelength, such devices produce no energy. Submerged shallow sea bed mounted devices must be placed well below the average wave or swell trough depth to survive breaking waves in severe sea-states. Wave induced static pressure differences diminish rapidly with depth in shallow water. Shallow water sea bed mounted devices must be rugged and therefore costly as well as inefficient. Unlike the present invention, depth of sea bed devices can not be adjusted for tides. [0013] Gardner (U.S. Pat. No. 5,909,060) also proposes a twin chamber shallow sea bed device which is essentially two inverted open bottomed cup shaped air entrapped vessels spaced an “average” wavelength apart and rigidly connected by an air duct. One vessel rises as the other falls (like a swing) pumping hydraulic fluid for an hydraulic motor generator. The device is called an “Archemedes Wave Swing.” A single vessel open bottom shallow sea bed mounted variant ( FIG. 2 ) is also described, the upside-down air entrapped cup moves up and down in response to overhead wave induced static pressure variations driving a generator with a mechanical or hydraulic drive. Unlike the present invention, which uses an evacuated or surface or atmospheric vented closed vessel, Gardner's up and down movement, and therefore output and efficiency, is restricted because the vessel is not evacuated or vented to atmosphere or an accumulator. The entrapped air is, therefore, compressed thus restricting movement, efficiency, and output. The open bottom also presents problems such as weed fouling and air loss (absorption in water) not encountered in the closed vessel of the subject invention. Shallow water or sea bed mounting also raises costs and lowers efficiency as previously described in Van Den Berg above. [0014] Gardner licensed U.S. Pat. No. 5,909,060 to AWS Ltd. which published an “improved” evacuated enclosed vessel design in November 2007 (as depicted in FIG. 3 ). Air under partial vacuum is entrapped between a moving rigid (heavy) inverted cylindrical cup shaped upper vessel ( 11 in down position, 12 in up position) which slides over a similar slightly small diameter stationary up oriented cup shaped vessel affixed to the sea bed. Partial vacuum is maintained by a “flexible rolling membrane seal” ( 14 in down position and 15 in up position). To prevent frictional seal wear and binding between the moving and stationary cup, an elaborate marine foulable “ectoskeleton” or frame 16 with rollers 17 or skids is required. The movable inverted cup drives a hydraulic piston 18 providing pulsed pressurized flow on each down stroke. Unlike several embodiments of the present invention, no power is produced on the upstroke which is used to hydraulically return the piston 18 and movable inverted cup 11 and 12 to its' up position 12 . [0015] The present invention differs from the published AWS design of FIG. 3 in the following major ways: 1. The flexible elastomer bellows and smaller (plate not cup) light weight (fiberglass) moving surface of the present invention reduces total and moving mass several fold and is, therefore, several fold less costly (light weight flexible (elastomer) sidewalls vs AWS heavy rigid steel overlapping sidewalls). Low moving mass of the present invention greatly increases responsiveness allowing both wave and swell kinetic energy capture vs. the heavy AWS mass for swells only. Low moving mass also allows effective timing, or delayed release, of the compression and expansion strokes until the wave crest and trough, respectively, are overhead preserving precious stroke length until hydrostatic forces are at a maximum (for compression) and minimum (for re-expansion). This “latching” control alone can increase the energy capture efficiency of heaving mode OWECs several fold (see cited references Falnes & McCormick). 2. Certain preferred embodiments of the present invention use direct or indirect atmospheric venting, rather than the partial vacuum used by AWS which may be more difficult to maintain sea water leak free and may compromise hydraulic seals. Partial vacuum also results in some gas compression on the vessel compression stroke which reduces stroke and, therefore, energy capture. 3. Certain preferred embodiments of the present invention utilize overhead surface floating buoys connected to the flexible reinforced bellows container to enhance compression or expansion of said containers or otherwise supplement energy capture. 4. No expensive, heavy, high maintenance, marine debris fouled ectoskeleton/cage with exposed rollers (to maintain concentric cylinder in cylinder movement) is required for the present invention. 5. No “flexible rolling membrane seal” (a fragile high wear, high maintenance item) is required with the present invention. Partial container evacuation combined with hydrostatic seawater pressure draws this seal into the container interior reducing container volume and increasing seal wear. 6. The membrane seal and concentric overlapping cups of the AWS device restricts stroke to less than half that of a present invention device of comparable size, halving cost and doubling energy capture. 7. The “rolling membrane seal” limits the AWS device to a circular horizontal planar section. An oblong section possible with the present invention, may be oriented transverse to the wave front direction (parallel to the waves) and, can capture more energy per unit of horizontal planar area and width. The sides of a circle have very little frontal area and capture. 8. The rigid near shore sea bed attachment post of the AWS device ( 19 in FIG. 3 ) does not allow depth adjustment for tides or optimized energy capture or protection from severe sea-states like the adjustable depth mooring systems of the present invention. 9. Embodiments of the present invention use a force multiplier or leveraged connecting means and/or multi-staged or multiple sequenced drive cylinders to increase stroke while maintaining higher capture efficiency than the AWS device ( FIG. 3 ). 10. The device of the present invention, unlike the AWS device, can be oriented vertically (with either fixed or moving surface up), horizontally, to also capture lateral wave surge energy, or in any other orientation. [0026] Burns (2008/0019847A1, 2007/025384/A1, and 2006/0090463A1) and FIG. 4 also describes a submerged sea bed mounted pressurized gas filled cylindrical container 11 having a small diaphragm 39 flexibly connecting a rigid movable top 25 , 28 to the top of cylindrical side walls 17 . The top and attached small diaphragm move slightly in response to overhead swell induced static pressure changes driving a leveraged 63 hydraulic pump 47 . To overcome gas compression stroke limitations, Burns in some embodiments uses multiple adjacent gas interconnected containers, but they are too close to each other to be effective. North U.S. Pat. No. 6,700,217 describes a very similar container and small diaphragm, without gas evacuation, venting or gas interconnection. [0027] The present invention overcomes the limitations of Burns and North in like manner to the AWS/Gardner limitations described in 1-10 above. More particularly or in addition: 1. Neither Burns nor North use surface or atmospheric venting or partial evacuation like the present invention to reduce container gas compressive/resistance and greatly increase stroke and energy capture. 2. Neither Burns nor North or any other submerged vessel prior art use any means before, after on or floating above their vessels to focus or capture any kinetic wave energy representing 50% of all wave energy. Likewise no submerged vessel prior art use a mechanical connection between said submerged vessel and a surface float to increase the stroke and energy capture of said submerged vessel. 3. While Burns and North have less moving mass than AWS, their total mass (and therefore cost) is probably greater due to their heavy walled ( 11 and 17 ) ballasted sea bed mounted containers. 4. Burns' and North's small unreinforced diaphragms 29 severely limit their power stroke lengths to a small fraction of the overhead wave height and, therefore, a like small fraction of energy capture rather than a substantial or even majority stroke to wave height ratio of the present invention. 5. Burns' power stroke (and, therefore, energy capture efficiency) is limited by his return means, which uses stroke limiting container internal gas pressure. 6. Burns' attempts to improve his poor stroke and energy capture efficiency in his latest application (2008/0019847A1) by aligning a series of pressurized gas interconnected containers into the direction of wave travel in an “arculated” shape is ineffective in overcoming gas compressive resistance because his containers span less than ½ average wave length. 7. Sea bed mounting of Burns' devices further severely reduces potential energy capture efficiency because sea bed mounting places Burns' movable device tops substantially below average wave trough depth due to tides and severe sea-state device protection considerations. Wave induced static pressure fluctuations fall off drastically with increased depth in shallow water as previously stated. [0035] Meyerand U.S. Pat. No. 4,630,440 ( FIG. 5 ) shows a submerged sea bed deployed gas filled unreinforced bladder 18 within a larger rigid sea water filled container 26 . Meyerand's “bladder in a box” differs materially from the “reinforced flexible bellows” with one fixed rigid end surface and an opposing moving rigid end surface of the present invention. Meyerand's bladder is connected via an air duct to a second shore or surface floating bladder 34 . Sea water enters and exits the rigid container 26 , in response to overhead wave induced pressure changes on the bladder 18 , through a single opening pipe containing a sea water driven turbine-generator. Meyerand's '440 suffers the same limitations of near shore sea bed mounted hydrostatic pressure driven devices previously described. The long pneumatic hose 24 between the submerged container 26 with bladder 18 and the shore or surface based bladder 34 produces substantial pneumatic flow efficiency losses. It also reduces the submerged bladder response time limiting energy capture to long swells and not waves. Most significantly, to get Meyerand's “constant pressure” and “constant volume” two bladder system to reinflate when a trough is overhead (Meyerand's only “return means”), the operating “constant pressure” must be extremely high to support and lift the water column above it (45 psi per 100 ft. of water depth). This high “constant pressure”, “constant volume” gas needed for submerged bladder inflation severely limits submerged bladder volume changes and energy capture. The present invention does not use high pressure gas within the container and surface vent or bellows as its' return means. The container gas pressure is approximately one (1) atmosphere or lower allowing several times more stroke and energy capture. [0036] Margittai (U.S. Pat. Nos. 5,349,819 and 5,473,892) describes a flexible gas (air) filled submerged (sea bed placed) container which expands and contracts in response to overhead wave induced hydrostatic pressure changes. The rigid top surface is rigidly affixed to and drives a vertical 1 stroke sea water open cycle pump. Unlike the present invention, Margittai does not vent or evacuate his container (he actually “inflates” or pressurizes it to hold its shape against submerged hydrostatic pressure and to provide his only return or re-expansion means, thereby limiting his stroke and wave energy absorption several fold. Margittai uses a simple bladder unreinforced against external hydrostatic pressure, unlike the “reinforced bellows” of the present invention (reinforced against both internal vacuum and external hydrostatic pressure). Margittai relies upon severely stroke and efficiency limiting internal air pressurization for his return means rather than the mechanical or hydraulic return means of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS [0037] FIG. 1 is a submerged elevation sectional view of the Prior Art by Van Den Berg 1997/037123. [0038] FIG. 2 is a submerged elevation sectional view of the Prior Art of Gardner U.S. Pat. No. 5,909,060. [0039] FIG. 3 is a submerged elevation sectional view of the Prior Art of AWS Ltd. as described in the published 29 October-11 November “The Engineer” (pgs. 26 and 27). [0040] FIG. 4 is a submerged elevation sectional view of the Prior Art by Burns (2008/0019847A1). [0041] FIG. 5 is an elevation view of Meyerand U.S. Pat. No. 4,630,440. [0042] FIG. 6 shows a submerged elevation sectional view of a preferred embodiment of application Ser. No. 12/454,984 ( FIG. 15 ) incorporated herein by reference. [0043] FIG. 7 shows a submerged elevation sectional view of one embodiment of the present invention comprising a vertically oriented partially evacuated or surface vented reinforced flexible bellows container with a said second moving surface extended beyond said bellows top and inclined toward prevailing wave fronts driving a telescoping hydraulic cylinder powering a sea bed hydraulic motor generator. Mooring, tidal depth adjustment, and depth fixing means are also shown. [0044] FIG. 8 shows submerged elevation sectional ( 8 a ) and plan view ( 8 b ) of one embodiment of the present invention comprising an expanded partially evacuated or surface vented reinforced flexible bellows container, said bellows being flexibly inclined toward prevailing wave fronts. Said second moving surface is extended both forward and down (towards oncoming waves) and rearward and upwards for increased wave kinetic energy capture. Said bellows extensions having spring loaded vents or flaps reducing hydrodynamic drag when said second moving surface is re-extended. [0045] FIG. 9 shows a submerged elevation sectional view of one embodiment of the present invention similar to FIG. 8 , but comprising a hinged movable surface over said second moving surface, said hinged surface driving a hydraulic cylinder supplementing the hydraulic drive cylinder within said bellows. [0046] FIG. 10 shows submerged elevation ( 10 a ) and plan ( 10 b ) views of one embodiment of the present invention comprising a fixed depth inclined shoaling plane in front of said bellows container and a fixed wave reflective wall behind said bellows container, relative to the direction of oncoming waves. Wave funneling and focusing means are also incorporated. [0047] FIG. 11 shows an elevation view of a preferred embodiment of the present invention similar to FIG. 8 except also comprising a floating surface vent buoy mechanically connected through a lever to said submerged container so as to assist in compression and expansion of said container when waves and troughs, respectively pass overhead. [0048] FIG. 12 shows an elevation partial (cutaway) sectional view of an embodiment of the present invention comprising a submerged vertically oriented bellows chamber with extended and inclined moving said second surfaces vented to and lever connected to a surface floating bellows. An air turbine generator produces power from alternating gas flow through a duct connecting said bellows. [0049] FIG. 13 shows a submerged isometric view of one embodiment of the present invention showing multiple partially evacuated or surface vented elongated flexible bellows containers having common inclined said second moving surface extending both forward (toward oncoming waves) and rearward and common fixed first surface hinged together. DESCRIPTION OF PREFERRED EMBODIMENTS [0050] FIGS. 1-5 show prior art previously discussed. FIG. 6 shows a preferred embodiment of U.S. patent application Ser. No. 12/454,984 (FIG. 15) incorporated herein by reference and of which this application is a Continuation-in-Part. [0051] FIG. 7 shows an embodiment of the present invention similar to FIG. 6 . Stationary surface 1 (sealed to a reinforced flexible bellows 3 ) is part of a molded or fabricated lower hull 100 which may have integral buoyancy chambers 101 . Moving surface 2 is part of upper hull 102 which may also contain buoyancy chambers 101 which may also serve as expansion chambers. Flexible bellows 3 is supported against external hydrostatic pressure and, optionally internal partial vacuum, by (internal only) support rings 6 . Bellows expansion return is via return spring 44 which return can be assisted or replaced by the 3 stage telescoping hydraulic drive cylinder 103 . Bellows internal support rings 66 could be replaced by a helically wound spring (not shown) also serving as said return means. Said bellows 3 and drive cylinder 103 are protected from severe lateral loads and deflection if required by an internal central slide tube or rails sliding within mating tubes or rails 105 in both the top and bottom hulls. Such sliding is facilitated by rollers or bearings 106 . The bellows 3 is further supported against lateral or shear loads by cross members 107 also rolling on said slide tube or rails 104 . The drive cylinder 103 is hydraulically connected to a sea bed mounted “power pod” 110 via hydraulic lines 108 and 109 passing through a rigid mast or spar 111 . Said single “power pod” can service multiple bellows via additional hydraulic lines (not shown). The upper mast 111 houses or supports a tidal depth adjusting jack screw 112 driven by electric or hydraulic jack screw drive 113 . Said power pod is sealed against sea water and houses high pressure hydraulic fluid accumulator tanks 114 , hydraulic motor 115 , electric generator 116 , and controls. The hydraulic circuit contains control valves 117 on high pressure supply and low pressure return lines which may be used to delay or time the drive cylinder 103 power (down) stroke and return stroke until the wave crest 5 or trough (shown), respectively, are overhead, for maximum stroke length and energy capture (per Ref. cited and included “latching” by Falnes and McCormick). Fixed surface 1 is held in deep water at a relatively fixed depth by the buoyance of the gas filled bellows container 4 and any buoyance chambers 101 and drag planes, plates or discs 118 . Said spar 111 and said container can be held in a relatively vertical position by three or more upper cables 119 and three or more lower cables 120 affixed to three or more anchor points 121 . The upper surface 125 of upper hull 102 is inclined toward prevailing waves with the leading extension 126 curving slightly downward creating an “artificial shoal” increasing the wave height above it (and hydrostatic pressure below it) and producing and absorbing supplemental “surge” kinetic energy. The trailing extension 127 curves upward directing waves upward and also reflecting waves back, both also increasing wave height and energy capture [0052] FIG. 8 shows an embodiment of the present invention similar to FIG. 7 . Like FIG. 7 , upper said moving surface 125 has leading 126 and trailing 127 extensions as well as lateral extensions 128 to increase wave height and capture horizontal (surge) wave kinetic energy component. To reduce the hydrodynamic drag of these extensions, hinged 130 vents or flap panels ( 131 leading and 132 trailing) are spring loaded 133 about said hinges 130 such that lateral wave particle motion keeps said panels closed when waves move overhead and said bellows containers 4 are compressing and said springs 133 open said panels 131 and 132 when troughs are overhead and said bellows containers 4 are re-expanding reducing return stroke drag losses. Unlike FIG. 7 , the central axis of movement 134 of said bellows chambers 4 is rotatably inclined forward about hinge 140 preferably from 20 to 120 degrees (from vertical up), and more preferably from 30° to 90°, to capture a larger portion of oncoming wave horizontal (surge) kinetic energy component which both compresses container 4 and rotates it rearward about hinge 140 . Said rotation about hinge 140 compresses supplemental hydraulic drive cylinders 141 . Such rotation is restored after each wave surge by return springs 142 on said drive cylinders 141 , or spring 143 attached to said fixed mast 111 . Such surge component is increased by the “artificial shoal” forward extension 125 which extension should preferably be from 90° to 150° regardless of the orientation angle of said containers central axis of movement 134 . Container extended top moving surface 125 also has vertical “side shields” or vanes 135 to prevent oncoming waves piling up on extended surface 125 from prematurely spilling off before driving surface 125 downward. Said side shields 135 are converging providing a wave funneling or focusing effect. Said side shields 135 also keep said bellows container oriented into oncoming wave fronts. [0053] FIG. 9 shows an embodiment of the present invention similar to FIG. 8 except that a movable upper surface 137 curving or extending upwards and rotatably hinged 138 to said moving second surface 125 drives supplemental hydraulic drive cylinder 139 (with optional return spring). Alternatively, said hinged surface 137 could also drive main drive cylinder 103 if its' shaft were extended (and sealed) through surface 125 (not shown). [0054] FIG. 10 a (elevation) and 10 b (overhead plan view) show submerged embodiment of the present invention similar to FIGS. 8 and 9 . Like FIG. 8 or 9 , said containers axis of compressive movement is inclined forward. Said container is rigidly attached to the fixed depth mast of spar 111 rather than pivoting (like FIGS. 8 and 9 ). Said inclination angle can be adjusted by compression bolt 155 . Like FIG. 7 , said mast or spar 111 has a retractable section 145 allowing the devices above it to be raised or lowered in depth to compensate for tides, average wave height, or severe sea states. The bellows container 3 and mooring system can be of construction similar to that described in FIG. 7 . Said bellows container 3 is shown in the compressed position with wave 5 cresting directly overhead. Like FIG. 7 , said moving surface 2 has a central section 125 , a downward curved leading section 126 (facing toward oncoming prevailing wave fronts) and an upward curving section 127 . The fully expanded position of said bellows container 3 and said surfaces 125 , 126 , 127 are shown as dotted lines. Said moving surface also has vertical side walls 135 as described in FIGS. 8 and 9 . Said bellows container 3 is preceded by an “artificial shoaling” surface 146 which is inclined or curved downward which surface acts like a shallow sea bed bottom increasing wave height and converting deep water wave particle circular motion (and wave kinetic energy) into horizontal motion (wave surge motion) for enhanced capture by surfaces 125 and 127 . Said shoaling surface 146 has generally vertical converging side shields 147 . Said surface 146 is wider at its entrance 148 than at its exit 149 near said container downward curved leading section 126 . Said shoaling surface entrance 146 also has to relatively flat vertical surfaces 156 or wave refraction surfaces aligned with and extending from shoal entrance 148 all generally parallel to prevailing waves (crests and troughs). Said wave refraction surfaces 156 and shoaling surface converge, focus, or funnel additional wave height and energy on to and in to said bellows moving surface 125 , 126 , 127 increasing wave energy capture. Said shoaling surface 146 with side shields 147 and refracting surface 156 are fixably mounted by support arm 150 onto said stationary mast or spar 111 . [0055] Behind said bellows container 3 is a generally vertical wave reflecting wall 152 affixed to stationary mast 111 by its' support arm 153 . Wave crests 154 impacting said wall 152 reflect back over said bellows container 3 further increasing wave height 154 available for energy capture by bellows container 3 . Said reflecting wall 152 can be passive (as shown) or “active” if mounted in hinged manner with energy absorbing means (as per FIG. 11 ). [0056] FIG. 11 shows an embodiment of the present invention with forward and rearward extensions of central movable surface 125 like FIG. 7 , 8 or 10 . It may also be preceded by a fixed shoaling surface (not shown) like 146 of FIG. 10 with similar converging and refraction features. Like FIGS. 8 and 9 , said bellows container may be flexibly attached via hinged joint 140 to fixed mast 111 and have supplemental energy absorption means (cylinder 141 ) with optional mechanical return means (springs 142 ). Compression and expansion of bellows container 4 is supplemented by surface float base 161 with optional surface vent bellows 160 mounted above said base 161 attached at pivot 168 to said submerged bellows central moving surface 125 by multiple lever arms 165 rotating about fulcrum arm 162 hinge or pivot points 163 . The distant end of lever arm 165 is flexibly attached to multiple vertical connecting rods 166 at lower end hinge joint 167 . The flexible upper end joints 168 of said connecting rods 166 is attached to said surface float base 161 . Like FIG. 10 , a wave reflecting wall 169 can be attached to and span between the upper portions of said vertical connecting rods 166 . Because surface float base 161 with optional vent bellows 160 will have more vertical movement than said bellows moving surface 125 , said fulcrum pivot point 163 will be closer to the bellows pivot point 164 than said connecting rod pivot point 167 . For added travel and shock absorption, said connecting rod 166 can have a (spring 170 ) mounted telescoping section 171 . Said bellows float can be fitted with supplemental wave energy (pitch mode) drive cylinders 172 with return springs 173 . Said connecting rods 166 bases can also be fitted with supplemental drive cylinders 174 and return springs 175 . Reflecting wall 169 is connected to said connecting rods 166 . Alternatively, said reflecting wall could be affixed to the surface float base 161 . If the optional vent bellows 160 is used on top of the surface float 161 , then a flexible gas vent duct 176 is used to allow free gas flow between said submerged bellows container 4 and said floating surface vent bellows 160 . If no surface vent bellows 160 is used, the interior of bellows container 4 is partially evacuated to reduce interior gas compression resistance. [0057] FIG. 12 shows a sectional elevation of an embodiment of the present invention utilizing a fixed (shown) submerged inclined bellows container 4 (like FIG. 11 ) with an adjustable base hinged about pivot 140 with sublemental energy absorption by cylinder 141 and extended and curved bellows top surface ( 125 , 126 , 127 ) (also like FIG. 11 ). Fixed shoaling surfaces (like FIG. 10 ) or “active” (powered) wave reflective back walls (like FIG. 11 ), could also optionally be used. The submerged bellows container 4 is shown expanded with a trough overhead with and a vent surface bellows compressed by return springs 185 or weighted top surface 190 . When an ensuing wave crest passes overhead gas from said submerged bellows container 4 flows through duct sections 180 , 181 and 182 before passing through two-way air turbine generator 184 and through float base 161 expanding surface bellows 160 and tensioning float bellows return springs 185 or lifting weighted top 190 . When the next wave trough passes overhead, the tensioned return springs 185 compress said surface bellows 160 driving gas through said two way turbine generator 184 housed in the base of surface float 161 and then through duct section 180 and back into submerged bellows container 4 re-expanding it and tensioning its' return springs 186 . Internal concentric telescoping glide tubes or rails (as described for FIG. 7 ) can provide lateral stability if needed. Wave reflecting wall 181 can be at least partially hollow and also serve as gas duct 181 or house air turbine generator 184 (not shown). Like FIG. 11 , lever arm 165 , hinged about fixed fulcrum 163 , attaches moving submerged bellows surface 125 at pivot point 164 to telescoping spring loaded connecting rod 166 at attachment point 167 . [0058] FIG. 13 shows a submerged or semi-submerged embodiment of the present invention utilizing multiple partially evacuated gas tight elongated compressible bellows containers 4 mounted on a common base 190 held at relatively fixed depth by multiple downward masts or spars 111 with depth fixing, adjustment and mooring means as described in FIG. 7 . Common (shown) or multiple (not shown) moving upper surface 191 has a forward (oncoming wave facing) downward sloped section 192 optionally flexibly connected to said common base 190 by hinges 194 . The rearward upsloping section 193 of said common moving upper surface may also serve as a passive (shown) or active powered (not shown) wave reflector wall increasing wave height, and both hydrostatic and kinetic wave energy capture as previously described. Frontal inclined or downward sloping frontal section 192 acts as a shoaling surface further increasing wave kinetic energy capture as previously described (in FIGS. 7 , 8 and 9 ) or it may be preceded by a fixed shoaling surface (as described in FIG. 10 ). Base 190 can be hinged 140 to stationary masts 111 as previously described (in FIGS. 8 , 9 , and 11 ) with supplemental energy capture by cylinders 141 and return springs 142 or rigidly attached (not shown). Primary energy capture as overhead wave crests compress surface 191 towards base 190 is via hydraulic cylinders 103 with return springs 44 as previously described in FIGS. 7 , 8 , 9 , 11 and 12 . Elongated bellows containers as shown have major advantages over round “point source” wave energy absorbs by spanning more wave front per unit of container (or buoy) area or volume. Large containers arranged in series front to back, span a larger portion of each wave length (25% to 50% of total wave length) increasing wave capture efficiency. The hinged front 194 eliminates the need for lateral supports for drive cylinders 103 . [0059] Modifications, improvements, and combinations of the concepts described herein may be made without departing from the scope of the present invention.

An ocean wave energy device uses large gas filled and surface vented or partially evacuated flexible containers each having rigid movable ends and rigid fixed depth ends connected by flexible bellows, suitably reinforced against external hydrostatic pressure, submerged to a depth below anticipated wave troughs. One or more said containers compress and expand as waves and troughs, respectively, pass overhead driving hydraulic or pneumatic, pumping means producing pressurized fluid flow for a common sea bed motor-generator or for other uses or on-board direct drive generators. Mechanical, hydraulic or pneumatic means re-expand said containers when a wave trough is overhead. Power output is augmented by mechanically connecting said rigid moving surfaces to surface floats, which may also provide said submerged container venting such that as waves lift and troughs lower said floats, said containers are further compressed and re-expanded, respectively. Power output is further augmented by wave kinetic energy capture through focusing, reflection and refraction.

big_patent

FIELD OF THE INVENTION [0001] The invention pertains to the field of scraped surface heat exchangers. More particularly, the invention pertains to the mounting of blades for a scraped surface heat exchanger onto the central drive shaft. BACKGROUND OF THE INVENTION [0002] Scraped surface heat exchangers are in wide use in industry, for example in the processing of foodstuffs. A scraped surface heat exchanger generally includes a long cylindrical outer tube having a material inlet at one end and a material outlet at the other end. A central drive shaft extends inside the outer tube and is coaxial with the outer tube and is driven to rotate inside the outer tube. An annular space between the outer tube and central drive shaft receives the material, such as a foodstuff, which is pumped in the inlet and allowed to travel the length of the tube and escape out the outlet at the other end of the outer tube. Heating or cooling is generally provided to the outer tube so that material changes temperature as it traverses the length of the scraped surface exchanger. Further, radially extending paddles, also referred to as blades, are hingedly connected to the central drive shaft in order to help mix the material and/or scrape the inside surface of the outer tube to prevent material buildup. [0003] In one known way of mounting the blades to the tube, the blade is in the form of a generally rectangular relatively thin flat blade member, with a scraping edge along one side, and an opposed hinge side which is hingedly connected to the drive shaft by means of pins. The pins are items welded onto the drive shaft and generally have a narrow protruding finger as well as an opposed wider finger. The thickness of the blade is dimensioned to slide between the two figures of the pin at an installation angle, and a hole is provided in the blade to which the inner finger can pass through. After the blade is inserted at the installation angle, it is pivoted to a much more shallow angle more tangential with drive shaft, at which point the inner finger protrudes through the hole in the blade thereby restraining the blade from lateral movement and permitting only angular movement. A blade typically has two such mounting connections, i.e., two pin receiving holes. The shaft is provided with pins at appropriate locations so that each blade is typically restrained by two, or sometimes more, of these hinged pin connections. [0004] The blades are generally installed on the drive shaft in this manner at a time when the drive shaft is removed from the outer tube of the scraped surface heat exchanger. Installation occurs not only at initial setup, but also after each cleaning cycle of the device, which can occur frequently. During insertion of the drive shaft into the scraped surface heat exchanger tube, it is desirable that the blades remain at the shallow angle so that the fingers are protruding through the holes in the blades and the blades are retained in place during installation. Further, the blades need to be held at their relatively shallow angle during installation so that they fit within the diameter of the outer tube and the drive shaft can be slid into the outer tube. [0005] In the case of a horizontally and vertically arranged scraped surface heat exchanger, this practice may be somewhat cumbersome and require tying strings around the blades to hold the blades in, or may be accomplished by the user holding the blades in with their hands as the drive shaft is inserted into the outer tube. [0006] Due to the length of a drive tube, there are typically several blades arranged at regular intervals longitudinally along a single drive shaft. Also, the blades are generally arranged with four blades, each at a 90° angle to each other, around the circumference of the drive tube, at each blade location. [0007] It would be apparent that if the blades are permitted to swing outwardly to their installation position, depending on their orientation, they may be able to freely slide away from the pin, since the inner finger is not restraining them by engagement with the hole in the blade. This problem becomes even more severe in the case of a vertically arranged scraped surface heat exchanger. In order to permit a shaft, which in some instances may be 7-8 feet long, to fit within a tube of the same length, it is known to mount the tubes quite high above the floor surface, and insert the drive shaft using a hydraulic lift controlled by a manually actuated lever at the floor level. With a vertically oriented tube in this configuration, during installation if the blades swing out to their installation angle position, they will then fall freely downward, which is undesirable and requires the operator to reposition them again before proceeding. [0008] Accordingly, is would be desirable to have a method and apparatus to facilitate the mounting of a scraped surface heat exchanger blade onto a drive shaft, while still using a pin type connection. SUMMARY OF THE INVENTION [0009] The foregoing needs are met, to a great extent, by the present invention, wherein in one aspect an apparatus is provided that in some embodiments facilitates the mounting of a scraped surface heat exchanger blade onto a drive shaft, while still using a pin type connection. [0010] In accordance with one embodiment of the present invention, a blade for mounting to a scraped surface heat exchanger drive shaft by pivotal connection with at least one mounting pin, the blade comprising a blade body having a first side and a second side, and a scraper edge and a hinge edge, at least one mounting hole extending through the blade body generally proximate to the hinge edge, a first L-shaped locking track protruding into the first side of the blade, having a first entry track extending from the hinge edge and a first intermediate track extending from the first entry track to the mounting hole, and a second L-shaped locking track protruding into the second side of the blade, having a second entry track extending from the hinge edge and a second intermediate track extending from the second entry track to and past the mounting hole. [0011] In accordance with another embodiment of the present invention, a scraped surface heat exchanger, comprising a drive shaft having at least one mounting pin mounted to the drive shaft, and a blade having, a blade body having a first side and a second side, and a scraper edge and a hinge edge, at least one mounting hole extending through the blade body generally proximate to the hinge edge, a first L-shaped locking track protruding into the first side of the blade, having a first entry track extending from the hinge edge and an intermediate track extending from the entry slot to the mounting hole, and a second L-shaped locking track protruding into the second side of the blade, having a second entry track extending from the hinge edge and an intermediate track extending from the second entry track to and past the mounting hole. [0012] In accordance with another embodiment of the present invention, a blade for mounting to a scraped surface heat exchanger drive shaft by pivotal connection with a mounting pin, the blade comprising a blade body having a first side and a second side, and a scraper edge and a hinge edge at least one receiving means extending through the blade body generally proximate to the hinge edge, a first L-shaped locking means protruding into the first set of the blade, having an entry track extending from the hinge edge and an intermediate slot extending from the entry track to the pin receiving means, and a second L-shaped locking means protruding into the second side of the blade, having a second entry track extending from the hinge edge and a second intermediate track extending from the second entry slot to and past the pin receiving means. [0013] In accordance with another embodiment of the present invention, a method for mounting a blade to a scraped surface heat exchanger drive shaft by pivotal connection with a mounting pin, comprising providing a blade body having a first side and a second side, and a scraper edge and a hinge edge with at least one mounting hole extending through the blade body generally proximate to the hinge edge, and locking the blade against longitudinal movement in one direction while permitting pivoting movement relative to the drive shaft, using tracks on both sides of the blade interfering with the pin. [0014] There has thus been outlined, rather broadly, certain embodiments of the invention in order that the detailed description thereof herein may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional embodiments of the invention that will be described below and which will form the subject matter of the claims appended hereto. [0015] In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of embodiments in addition to those described and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein, as well as the abstract, are for the purpose of description and should not be regarded as limiting. [0016] As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS [0017] FIG. 1 is a perspective view of a scraped surface heat exchanger blade according to a preferred embodiment of the invention. [0018] FIG. 2 is a plan view of the blade of FIG. 1 showing a first, inner side thereof. [0019] FIG. 3 is a plan view of the blade of FIG. 1 showing a second, outer side thereof. [0020] FIG. 4 is a side view of the blade of FIG. 1 . [0021] FIG. 5 is a side view of the blade of FIG. 1 taken from the opposite side of FIG. 4 . [0022] FIG. 6 is an end view of the blade of FIG. 1 . [0023] FIG. 7 is an end view of the blade of FIG. 1 taken from an opposite end thereof. [0024] FIG. 8 is a plan view of a pin used in a preferred embodiment of the invention. [0025] FIG. 9 is a front view of the pin of FIG. 8 . [0026] FIG. 10 is a side of the pin of FIG. 8 . [0027] FIG. 11 is a perspective view of a blade and pin assembly at the beginning of the installation process. [0028] FIG. 12 is a perspective view of a blade and pin assembly at the beginning of the installation process. [0029] FIG. 13 is a perspective view of a blade and pin assembly during a next step of the installation process. [0030] FIG. 14 is perspective view of a blade and pin assembly at the step of FIG. 13 . [0031] FIG. 15 is a perspective view of a blade and pin assembly during a next step of the installation process. [0032] FIG. 16 . is a perspective view of a blade and pin assembly at the step of FIG. 15 . [0033] FIG. 17 is a perspective view of a blade and pin assembly at a final step of the installation process and in an operative position. [0034] FIG. 18 . is a side view of a blade and pin assembly in the installed orientation corresponding to FIG. 17 . DETAILED DESCRIPTION [0035] Referring now to the drawings, in which like reference numerals refer to like parts throughout, a blade 12 according to the preferred embodiment is illustrated in FIGS. 1-7 . The blade 12 includes a first side 14 , which is a radially inwardly facing side of the blade in the installed operative state, and a second outwardly facing side 16 , which is outwardly facing in the installed state. [0036] A blade edge 18 is provided at one side of the blade, and is opposite to a hinge edge 20 . A pair of mounting holes 22 are provided in the blade as shown. Each mounting hole 22 extends completely through the thickness of the blade 12 . Turning to FIG. 2 , in particular, one of the holes 22 has adjacent to it a L-shaped track 24 , which includes an entry track 26 and intermediate track 28 . FIG. 2 illustrates a blade with 2 mounting holes 22 , having a first track 24 associated with one mounting hole 22 and a second slot 30 associated with the other mounting hole 22 . The second track 30 is substantially identical to the track 24 and includes an entry track 26 and an intermediate track 28 . [0037] Turning to FIG. 3 , on the other side of the blade, one mounting hole 22 is shown with a locking track 34 , which includes an entry track 36 and an intermediate track 38 . Intermediate track 38 is present on both sides of the hole 22 . Associated with the other hole 22 is another locking track 38 , which is substantially identical to locking track 34 , and includes an entry track 36 and a intermediate track 38 . [0038] Turning to FIG. 8 , a representative pin 40 is illustrated. The pin 40 includes an inner finger 42 as well as an outer finger 44 and a base 46 which is mounted to the drive shaft of the scraped surface heat exchanger, usually by welding. FIGS. 9 and 10 show further details of the pin 40 . [0039] The mode of installation of a blade 12 onto a shaft by virtue of the locking tracks will now be described with reference to FIGS. 11-18 . FIGS. 11 and 12 show the blade 12 at the beginning of the installation sequence. The blade 12 is placed at an angle relative to the pins 40 corresponding to the angle illustrated in FIG. 10 . Turning back to FIGS. 11 and 12 , can be seen in FIG. 11 that the upper fingers 44 are each aligned with respective entry tracks 36 . The entry tracks 36 have a width that is preferably just slightly greater than the width of the outer finger 44 . Turning to FIG. 12 , it is appreciated that the inner fingers 42 are aligned with respective entry tracks 26 , with the entry tracks 26 having a width slightly greater than the width of the fingers 42 . [0040] Turning to FIGS. 13 and 14 the blade is now being inserted between the fingers 44 and 42 of the pin 40 . FIG. 13 illustrates the outer finger 44 sliding into the entry tracks 36 . FIG. 14 illustrates the inner finger 42 sliding into the entry tracks 26 . At this point, due to the angled surface of the inner finger 42 , the blade is held at angle alpha by contact between the fingers 42 and 44 . [0041] Turning now to FIGS. 15 and 16 , the blade has been moved longitudinally so that the inner fingers 42 are now aligned with the mounting holes 22 . The inner fingers 42 have traversed the intermediate tracks 28 . The outer finger 44 has traversed the intermediate track 36 . It would be appreciated that the intermediate slot 28 extends only as far as to the hole 22 , because the inner finger 42 will now fit within the mounting hole 22 . However, the intermediate slot 38 extends past the hole 22 , to accommodate the width of the outer finger 44 . [0042] In the position shown in FIGS. 15 and 16 , the blade 12 is illustrated at the angle alpha. In this position, the blade 12 could be slid back towards the position shown in FIGS. 13 and 14 . However, travel in the opposite direction is prevented due to the fact that the intermediate track 28 does not extend past the hole 22 . In the case of a vertically oriented scraped surface heat exchanger, the arrangement would be positioned so that direction shown by the arrow U in FIG. 16 refers to upward, and the direction indicated by the arrow D would refer to downward. In the case of either a horizontal or vertical heat exchanger, the direction indicated by U would typically indicate a direction of insertion of the drive shaft, and the direction indicated by D would indicate a direction of removal. [0043] Turning to FIGS. 17 and 18 , the blade 12 is now shown located longitudinally in the position shown in FIGS. 15 and 16 , i.e., with the inner fingers 42 aligned with the mounting holes 22 , but has now been angularly rotated downward into an installation position, as particularly seen in FIG. 18 , wherein the blade 12 is at a sufficiently shallow angle to fit within an outer tube 50 of the heat exchanger of being mounted to the drive shaft 52 by the pins 40 . [0044] Looking particularly at FIGS. 15, 16 , and 17 , it will be appreciated that, especially in a vertical orientation, the blades will not fall downward off the pins no matter what angle they are at. That is, even if the blade is at the installation angle alpha, shown in FIGS. 15 and 16 , it still cannot travel downward in the direction D, due to interference present on both sides of the blade. Primarily, the blade is restrained by interference between the top of the finger 42 and the top edge of the opening 22 . On the other side, the blade can also be restrained from vertical travel by the interference between the top edge of the outer finger 44 , and the top of the intermediate track 38 . [0045] This provides a significant benefit of at least some embodiments of the invention, wherein, where the heat exchanger is vertically, each blade can be positioned at the installation angle, slid onto the pins, and then slid downwardly along the pins, until reaching the position shown in FIGS. 15-17 . At this point, even if the blades are left free to pivot about any angle in the range of pivot permitted by the pin, the blades will still stay oriented (with their holes 22 aligned with the inner fingers 42 ) and will not be able slide down or otherwise fall off the pins. [0046] Another advantage of this embodiment is that the entry track 26 is a different width than the entry track 36 . As a result, the blade can only be slid onto a pin with the inner side 14 facing downward, i.e., facing towards the inner finger 42 , and with the outer side of the blade 16 facing upward, i.e., facing the upper finger 44 . This ensures that the blade will be installed with the correct side facing up, and hence in the case of the scraper design shown in FIG. 18 , that the scraper edge will be correctly oriented against the inside of the outer tube 50 of the scraped surface heat exchanger. [0047] The only way to remove a blade in this configuration, is to raise the blade, i.e., translate it in the direction shown by arrow U in FIG. 16 , until the blade reaches the positions shown in FIGS. 13 and 14 , at which point they can be slid off the pins into the positions shown in FIGS. 11 and 12 . [0048] Another advantage of the illustrated embodiment, is that the provision of locking tracks is accomplished using tracks on both sides of the blades. This is an advantage because in order to preserve the structural rigidity of the blade, it is desirable that as much of the blade as possible be of the greatest thickness, i.e., close to the same as the overall blade thickness. In order to accomplish the sliding along the tracks, as well as the interference locking features, the blade tracks on the fingers must be dimensioned with some degree of clearance to permit sliding, but with sufficient degree of interference to prevent any out of track movements. By putting tracks on both sides of the blade, each track can be made roughly half as thick as would be required for a single track on one side of the blade. Over time, both blades and pins are subject to wear, and providing the tracks on both sides permits acceptable performance while reducing the amount of thinned track blade area compared to what would be necessary in an arrangement utilizing the tracks only on one side of the blade. [0049] The many features and advantages of the invention are apparent from the detailed specification, and thus, it is intended by the appended claims to cover all such features and advantages of the invention which fall within the true spirit and scope of the invention. Further, since numerous modifications and variations will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation illustrated and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.

A blade for mounting to a scraped surface heat exchanger drive shaft by pivotal connection with a mounting pin has a blade body having a first side and a second side, and a scraper edge and a hinge edge. At least one mounting hole extends through the blade body generally proximate at the hinge edge. An L-shaped locking track protrudes into the first set of the blade, having an entry track extending from the hinge edge and an intermediate track extending from the entry track to the mounting hole. An L-shaped locking track also protruding into the second side of the blade, has an entry track extending from the hinge edge of the blade and an intermediate track extending from the entry track to and past the mounting hole.

big_patent

BACKGROUND OF THE INVENTION The invention relates to a process and an apparatus for detecting, and to a process and an apparatus for eliminating, defective and/or incorrectly positioned, in particular transversely located, cigarettes in the cigarette magazine of a cigarette-production and/or cigarette-packaging machine. Cigarette production and/or cigarette packaging machines usually have a cigarette store in which cigarettes, as they move downwards, end up being located transversely to the rest of the cigarettes and can block individual shafts or shaft groups located beneath the storage part. The following cigarettes can then no longer pass into the respective shafts or shaft groups. This results in the respective shafts or shaft groups being put out of action. The task of eliminating such disruptions is laborious and costly since it is usually necessary to switch off the machine. In order to avoid costly steps involved in eliminating disruptions to a blocked shaft or shaft group, an operator usually watches the cigarette magazine and removes any transversely positioned cigarette with long pincers. Here there is a risk of human error since, on account of the monotony of the task, the operator's attention decreases over time. Furthermore, disruptions which remain undetected may take place when the operator is absent. The problem on which the invention is based is thus to improve the avoidance of disruptions in the cigarette magazine. SUMMARY OF THE INVENTION In order to solve this problem, a detection process according to the invention is characterized in that, using at least one optical checking element, at least one image of a plurality of cigarettes located in the cigarette magazine is detected, the image is evaluated by an image-processing device and—if, during the evaluation, the scanned image is established as deviating from a reference image and/or from at least one reference value—an error signal is produced. A detection apparatus according to the invention is characterized by an optical checking element, in particular a camera, which is arranged in the region of the cigarette magazine and is intended for scanning at least one image of a plurality of cigarettes located in the cigarette magazine, by an image-processing device for evaluating the image and by means by which an error signal can be produced if the scanned image is established as deviating from a reference image and/or from at least one reference value. The advantage of this process and of this apparatus is the monitoring of a relatively large area of cigarettes rather than merely individual cigarette ends, since this provides an overview of the orientation of the cigarettes. Provision is thus made for detecting an image of a relatively large area of the cigarette magazine, namely a plurality of cigarettes, and for subjecting this to image processing. Finally, using image-processing methods, deviations from reference images and/or reference values can be established and, if necessary, a corresponding error signal can be produced. This makes it possible to detect transversely located cigarettes. Furthermore, this process and this apparatus may also be used to register defective cigarettes in addition to incorrectly positioned cigarettes. For example, in the case where images of filter cigarettes are stored, a missing filter can be diagnosed by image processing. However, it is also possible to register bent or broken cigarettes, since these too constitute a deviation from a reference image. A disruption detected in this way can be eliminated automatically or manually. With a manual elimination of disruption, the error signal is preferably emitted acoustically or optically, e.g. by a siren or horn or by a warning light. Such a signal then tells the operator to intervene. However, errors may also be eliminated automatically. In order to solve the problem further, an elimination process according to the invention is characterized in that a defective and/or incorrectly positioned cigarette is detected, in particular in accordance with one of the processes described above, and, in reaction to such detection, an ejecting unit arranged in the region of the magazine is actuated in order to eject a plurality of cigarettes located in an ejecting zone assigned to the ejecting unit. An elimination apparatus according to the invention is characterized by at least one, or in particular a plurality of, adjacent ejecting unit which are arranged in the region of the magazine and are intended for ejecting a plurality of cigarettes located in an ejecting zone assigned to an ejecting unit. The number of cigarettes ejected in this case is large enough for a transversely located cigarette to be ejected in full. A plurality of adjacent ejecting zones with a corresponding number of ejecting units are preferably provided. This has the advantage that it is not necessary to eject the cigarettes over the entire width of the cigarette magazine. It may thus be the case that a transversely located cigarette extends over two ejecting zones. In this case, preferably two adjacent ejecting units are actuated and a correspondingly larger number of cigarettes is ejected. BRIEF DESCRIPTION OF THE DRAWING The front and rear walls of the ejecting unit are preferably of different sizes and contours such that the contour of the rear wall is greater than the contour of the front wall by at least the width of one cigarette. This avoids jamming of cigarettes only partially gripped by the front wall. Further details of the invention can be gathered from the subclaims and with reference to an exemplary embodiment illustrated in the drawing, in which: FIG. 1 shows a front view of a cigarette magazine with a camera and four ejecting units arranged in the storage part of the cigarette magazine; FIG. 2 shows an enlarged detail of the storage part with a plurality of ejecting units and a plurality of schematically illustrated ejecting zones and evaluation zones; FIG. 3 shows the cigarette magazine from FIG. 1 in a side view along section line III—III according to FIG. 1 with an ejecting unit in the through-passage position; and FIG. 4 shows the cigarette magazine from FIG. 3 with an ejecting unit in the ejecting position. DETAILED DESCRIPTION OF THE INVENTION FIG. 1 shows a cigarette magazine 10 which has a storage part and four shaft groups 12 arranged therebeneath. Each of these shaft groups has seven shafts of essentially the width of one cigarette. The cigarette magazine 10 contains a plurality of cigarettes 13 , illustrated by circles. With the correct positioning of these cigarettes 13 , it is only the filter-side or opposite end of the cigarette 13 which can be seen in the front view illustrated in FIG. 1 . In other words, the plurality of cigarettes are located parallel to one another and are aligned horizontally, the ends of all the cigarettes 13 ideally being located essentially in a vertical plane. The depth of the cigarette magazine 10 , in particular the depth of the space of the cigarette magazine 10 which receives the cigarettes 13 , corresponds essentially to the length of one cigarette or is slightly larger than the length of one cigarette. The cigarettes 13 pass through a top opening 14 into the cigarette magazine 10 . On account of the force of gravity, the cigarettes 13 move downwards into the. cigarette magazine 10 , where they pass to the shaft groups 12 . At the outlet of the shaft groups 12 , the cigarettes 13 are grouped in accordance with the formation which is to be received by a pack. Furthermore, the cigarette magazine 10 has four oscillating rods 15 which ensure that the cigarettes 13 are moved downwards uniformly into the shaft groups 12 . It is occasionally possible for a cigarette 13 within the cigarette magazine 10 to end up being located in a position which differs from the ideal alignment. For example, a cigarette 13 can skew. A cigarette positioned incorrectly in this way is illustrated as a transversely located cigarette 16 . If a transversely located cigarette 16 moves downwards over time in the direction of the shaft groups 12 , a blockage of such shaft groups 12 may occur. This usually results in the initially mentioned disruption to the production sequence. In particular the elimination of such disruption involves high outlay. The cigarette magazine 10 is thus provided with an optical checking element, namely a camera 17 . The camera 17 monitors the cigarette ends through a window or a transparent wall of the cigarette magazine 10 . In particular, the camera 17 scans an image of the cigarette magazine 10 over essentially the entire width of the cigarette magazine 10 . An image-processing device 18 evaluates the scanned image. In this case, the scanned image is compared with a reference image, for example. Alternatively, the scanned image is subjected to preprocessing, in which case characteristic values of the image are produced and/or calculated. By virtue of a comparison of these values with reference values, and/or of the scanned image with the reference image, errors can be detected, for example if there is a deviation or if a deviation exceeds a certain threshold value. Finally, a detected error results in the generation of an error signal, which results in at least one of four ejecting units 19 being actuated. This actuation causes the cigarettes 13 located in the region of the ejecting unit 19 to be pushed out to the rear side of the cigarette magazine 10 and thus ejected. The ejected cigarettes 13 drop into an inclined chute 20 along which the cigarettes 13 slide down and are finally fed to a tobacco-recycling circuit. The tobacco recycling takes place by the cigarette being divide up into tobacco, cigarette paper and filter. The recovered tobacco is finally reused in cigarette production. This means that the tobacco waste which is produced when, as a transversely located cigarette is ejected, a plurality of other non-defective or correctly positioned cigarettes are likewise ejected can be kept low. Each ejecting unit 19 has a housing 21 which is fixed relative to the cigarette magazine 10 or is connected thereto. The housing 21 has a linear cylinder which serves for guiding a linearly displaceable carriage 22 . Said carriage 22 , in turn, is connected to the actual ejector 23 of the ejecting unit 19 . The ejector 23 has a front wall 24 and a rear wall 25 (illustrated in FIG. 3 ). The front wall 24 and rear wall 25 are connected to one another by a connecting element, namely a connecting rod 26 . If the ejecting unit 19 is located in a position referred to as a “through position”, the front wall 24 of the ejector 23 terminates essentially flush with the front inner side of the cigarette magazine 10 and the rear wall 25 of the ejector 23 terminates essentially flush with the rear inner side of the cigarette magazine 10 . In this through position, the cigarettes 13 can pass the storage part 11 of the cigarette magazine 10 in the region of the ejecting unit 19 without obstruction. It is only the connecting rod 26 , which is of thin configuration, which results in a slight narrowing of the width of the cigarette magazine 10 in this region, which, however, is of no importance for the downward movement of the cigarettes 13 and thus for the cigarette transportation through the cigarette magazine 10 . If, however, the ejecting unit 19 is actuated, both the front wall 24 and rear wall 25 of the ejector 23 are displaced in the direction of the rear wall 25 of the ejector 23 and/or in the direction of the chute 20 . The front wall 24 of the ejector 23 is connected to a housing-like device 27 , of which the cross section corresponds to the contour of the front wall 24 of the ejector 23 . This housing-like device prevents cigarettes 13 from dropping into the region of the ejector 23 when the ejector 23 is located in the ejecting position. This makes it possible to avoid the situation where, when the ejector 23 is drawn back into its through position, cigarettes 13 which have dropped into this region block the ejector. Furthermore, the four front walls 24 and/or housing-like devices 27 of the four ejectors 23 are spaced apart from one another. The distance 28 between the front walls 24 corresponds approximately to double the width of one cigarette, but it may also be selected to be larger. FIG. 2 shows a detail of the storage part 11 of the cigarette magazine 10 in the region of the ejecting units 19 in an enlarged illustration. Four ejecting zones A to D are illustrated schematically above the ejecting units 19 . Each of these four ejecting zones A to D is assigned to an ejecting unit 19 . The cigarettes 13 located in an ejecting zone are ejected upon actuation of the corresponding ejecting unit 19 . Four evaluation zones I to IV are located above the ejecting zones A to D, with each ejecting zone A to D being assigned to the respective evaluation zone I to IV above it. The ejecting zones A to D are selected in terms of their dimensions such that the width and/or the length of each ejecting zone A to D corresponds at least to the length of one cigarette. In particular the width. of an ejecting zone is selected to be greater than the height of the corresponding ejecting zone. The evaluation zones I to IV correspond to the region monitored by the camera 17 . The camera 17 picks up an image of all the evaluation zones I to IV. During image processing, the image is subdivided into said four evaluation zones I to IV. Each of these four evaluation zones I-V is evaluated separately. If, in the region of an evaluation zone, a transversely located, that is to say incorrectly positioned cigarette, or a cigarette which is formed incorrectly in some other way, is detected, the corresponding ejecting unit 19 located therebeneath is actuated with a time delay. Said ejecting unit ejects the cigarettes 13 located in the corresponding ejecting zone A-D. The time delay between detection of a defective or incorrectly positioned cigarette 13 and actuation of the corresponding ejecting unit 19 is determined by the time required for such a cigarette to move downwards from an evaluation zone I-IV into an ejecting zone (approximately 10-20 seconds). As an alternative to a camera 17 , which records an image of all four evaluation zones I to IV, however, it is also possible to install a plurality of cameras 17 which each scan an image of an evaluation zone I-IV and then feed this to image processing. In the region of the evaluation zones I to IV, the front wall of the cigarette magazine 10 is of transparent configuration, for example by virtue of a glass or plastic panel being introduced, with the result that the camera 17 has a free view of the cigarette ends. FIG. 3 shows a section of a lateral view of the cigarette magazine 10 along line III—III from FIG. 1 . Two cameras 17 are provided, to be precise one on the front side, and one on the rear side, of the cigarette magazine 10 . The arrangement of two cameras 17 means that defective or incorrectly positioned cigarettes 16 can be detected more reliably. In the example shown, a transversely located cigarette 16 is located within the evaluation zone II. This transversely located cigarette 16 is detected by the cameras 17 . The image-processing device 18 evaluates the detected image of the transversely located cigarette 16 and—once the defectively positioned cigarette 16 has been detected—produces an error signal. This error signal results in the ejecting unit 19 being actuated. The ejector 23 is thus displaced in the direction of the chute 20 . For this purpose, the linear cylinder of the ejecting unit 19 together with the carriage 22 and the ejector 23 fastened thereon, including the housing-like device 27 , are displaced in the direction of the chute 20 . There is also a connecting element 29 located between the ejector 23 and carriage 22 . This connecting element 29 ensures the necessary distance between the carriage 22 and ejector 23 . This distance is such that the ejector 23 can be pushed into the cigarette magazine 10 to the extent where the front wall 24 of the ejector 23 reaches the rear wall 30 of the cigarette magazine 10 . FIG. 4 shows the ejecting unit 19 in the ejecting position, i.e. the ejector 23 is located in its left-hand or chute-side end position. In the position illustrated, the front wall 24 of the ejector 23 terminates with the outer surface of the rear wall 30 of the cigarette magazine 10 , with the result that the ejected cigarettes 31 —including the transversely located cigarette 16 —can drop into the chute 20 without obstruction. The housing-like device 27 , which is connected to the front wall 24 of the ejector 23 , blocks the cigarette magazine 10 in the region of this ejecting unit 19 , with the result that initially no cigarettes 13 can follow on in this region. It is only when the ejecting unit 19 is located in its through position (according to FIG. 3) again that cigarettes drop into the previously formed cavity again and thus refill the region of the relevant ejecting zone B. Although the ejecting unit 19 is generally only actuated when a defective or incorrectly positioned cigarette 16 has been detected, it may also be actuated for other reasons. In particular it is also possible for the ejecting unit 19 to be triggered manually. This is particularly expedient eliminating errors which are not detected automatically. Actuation of the ejecting unit 19 which is not manual or triggered by image processing is also employed to take samples (for example at regular time intervals). However, the detection of a defective or incorrectly positioned cigarette using a camera and downstream image processing, and a possibly triggered optical and/or acoustic error signal, may also lead to an operator eliminating disruption manually, in particular if an operation for eliminating the disruption automatically—for example by actuating the ejecting unit 19 —has failed or would fail. Overall, the greatest advantages can be achieved when the combination of the above-described automatic detection of a defective or incorrectly positioned cigarette is coupled to an ejecting unit. List of designations 10 Cigarette magazine 11 Storage part 12 Shaft group 13 Cigarette 14 Opening 15 Oscillating rod 16 Transversely located cigarette 17 Camera 18 Image-processing device 19 Ejecting unit 20 Chute 21 Housing 22 Carriage 23 Ejector 24 Front wall of the ejector 25 Rear wall of the ejector 26 Connecting rod 27 Housing-like device 28 Distance 29 Connecting element 30 Rear wall of the cigarette magazine 31 Ejected cigarette A Ejecting zone B Ejecting zone C Ejecting zone D Ejecting zone I Evaluation zone II Evaluation zone III Evaluation zone IV Evaluation zone

A process and an apparatus for detecting and eliminating, defective and/or incorrectly positioned, in particular transversely located, cigarettes in the cigarette magazine of a cigarette-production and/or a cigarette-packaging machine. Thus, the avoidance of disruptions in the cigarette magazine is improved. For detection using an optical checking element, an image of the cigarettes located in the cigarette magazine is scanned, the image is evaluated by an image-processing device and, if, during the evaluation, the scanned image is established as deviating from a reference image and/or reference value, an error signal is produced. For eliminating defective cigarettes, an ejecting unit arranged in the region of the magazine is actuated in order to eject a plurality of cigarettes.

big_patent

This application is a continuation of application Ser. No. 08/737,546 filed on Dec. 12, 1996, now U.S. Pat. No. 5,908,332 issued Jun. 1, 1999, which was a International Application PCT/EP95/03710 filed on Sep. 21, 1995 and which designated the U.S. BACKGROUND OF THE INVENTION 1. Technical Field The present invention relates to a device for interconnecting a high voltage cable with an apparatus and/or with a second high voltage cable consisting of a cable termination and a rigid insulator. 2. Description of the Prior Art When connecting such high voltage power cables in normal joints, in transition joints, to transformers and other SF6 and oil filled apparatus and accessories and out-door terminals, the interfaces are usually different for each application. SUMMARY OF THE INVENTION Therefore, the object of the present invention is to provide a simplified connection system for the above cables having ratings up to 400 KV and above. The features of the invention are defined in the accompanying patent claims. With the present invention there is obtained a common cable connection system for all accessories and interconnections. The interface between the cable end and any accessory, between two cable ends or between two apparatus is generally applicable, resulting in a number of advantages, such as factory pretesting, reduction of installation time and cost, reduction of tools and simplified field testing. The stress cone design and dimensions would also be the same for all applications, the only variation being the diameter of the cable or apparatus entrance. A further advantage is that the interface components does not include any gas or oil and, therefore, they cannot leak or explode. Above mentioned and other features and objects of the present invention will clearly appear from the following detailed description of embodiments of the invention taken in conjunction with the drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 to 3 illustrate three different principles of interface between a cable end and accessories, FIGS. 4 to 12 illustrate several applications of the invention, and FIG. 13 illustrates a rigid insulator corresponding to the rigid insulator shown in FIG. 4. DETAILED DESCRIPTION OF THE INVENTION In FIGS. 1, 2 and 3, there are illustrated three interface methods, - respectively called an inner cone concept, an outer cone concept and a no cone or slight inner cone concept The type of cone concept refers to the shape of the connector on the apparatus side. In all three figures an apparatus or accessory 1, 2 and 3 respectively, are indicated to the left. Connectors 4, 5 and 6 are respectively provided with an inner cone 7, an outer cone 8 and a slight inner cone 9. The interface could also be obtained by using plane contacting surfaces. To the right in FIGS. 1 to 3 are illustrated three cables 10, 11 and 12, respectively provided with terminations 13, 14 and 15 having end surfaces 16, 17 and 18 fitting the corresponding coned surfaces 7, 8 and 9. The conductor joints (plug-in, welding, clamping etc) are not part of the present invention and will not be described here. We have only indicated cable connectors 19, 20 and 21 on the cable terminations 13, 14 and 15 respectively. In the following detailed description of examples of cable connections we have chosen to show the outer cone concept, it being understood however, that the same series of interconnections can be obtained with the inner core concept and with the slight inner cone (or plane) concept. A general advantage of the outer cone concept over the inner cone is that the outer cone separates the cable connection further from the apparatus it is connected to, than does the inner cone Hence a fault at one side is less likely to affect the other side. The inner cone concept would have the advantage that a shorter solution could be used outside an SF6 cubicle. Problems with the coned surfaces may arise when components are made by different suppliers. The apparatus connectors are usually made of epoxy or similar non-compressible, rigid material, whereas the cable terminations usually are made of rubber and similar compressible or elastomeric materials. The outer cone concept would have the advantage over the inner cone concept that it is easier to expand the rubber material than to compress it An advantage of the substantially plane surface interconnection is that this simplifies complete alignment of the meeting surfaces without risking glow discharges. FIG. 4 and 5 illustrate the components of an SF6 terminal using the outer cone concept and the present invention As will be seen from the succeeding drawings, the concept of the cable termination illustrated in FIG. 4 is the generally applicable building block of all applications. A cable termination 30 shown in the lower past of FIG. 4 is arranged on a cable end 31 provided with a cable connector 32 and a stress relief cone 33 comprising a voltage deflector 34 as a stress relief device and a connector shield 35 embedded within a body 36 of elastomeric insulation. The body 36 of elastomeric insulation is covered by a conductive screen 39 and is enclosed within an outer rigid casing 38 The termination 30 fits to an interface device 40 including a rigid insulating body 41, e.g. made of an epoxy resin, having a conical interface surface 42 which fits to the interface surface 37 of the elastomeric body 36 of the termination 30. When the interface device 40 is used in connection with an SF6 terminal, the rigid insulator 41 is provided with a connector 43 which may have a compact version 44 or an IEC 859 standard (longer) version 45. In FIG. 5, there an SF6 termination of the present invention is illustrated. In addition to the components 30, 40 and 43, the drawing indicates an SF6 casing 46 and a connector 47. The usual hollow insulator used in conventional terminations is replaced by the compact or rigid epoxy body 41 around the conductor. Advantages over conventional terminals are: Compact design, lower material and installation cost, complete independence between gas insulated switch gear and cable installations, standardization. In FIGS. 6 and 7, there are illustrated two versions of transformer terminals. FIG. 6 shows an application of the invention with a transformer 50 having an oil-filled box 51 with a bushing 52 to which a cable termination 30 and connector 53 are connected. The connector 53 corresponds to the parts 40 and 43 in FIG. 4. In FIG. 7, a transformer 55 is provided with bushing 56 comprising the rigid insulating body 41 with the interface surface 42 which is connected directly to a cable termination 30, having the corresponding interface surface 37 as indicated in FIG. 4. This transformer terminal version is useful with the outer cone concept only. This version implies enhanced safety due to the omission of the oil-filled box with its highly combustible oil. In FIGS. 8 and 9 there are shown two versions of out-door terminals. In FIG. 8, the terminal 60 consists of components 30 and 40 combined with a conductor 61 which together with the epoxy insulator 40 is covered by tracking resistant FPDM rubber or silicone rubber sheath 62. This design eliminates the need for an oil- or SF6-filled insulator, while maintaining the mechanical rigidity of the omitted insulator. In FIG. 9, the out-door terminal 65 includes a surge suppressor device 66. This terminal is in principle similar to that described in U.S. Pat. No. 5,206,780 (J Varreng 6) The device 66, which consists of non-linear material such as ZnO or SiC, is separated from the conductor 67 by a layer of insulation material 68. The interconnections from the non-linear material layer, at the bottom to ground and at the top to the conductor 67 are not shown. The device 66 may be a continuous tube or it may consist of a number of series connected annular elements. The device 66 and insulator 40 are covered with tracking resistant EPDM rubber or silicone rubber sheath 69 as in FIG. 8. FIG. 10 illustrates a straight through joint 70. The epoxy component 40 is shaped as a symmetrical double cone which forms a center piece of a plug-in joint joining two cable terminations 30. This design may be more expensive than a pure elastomeric joint, but it has the advantage of factory testing and quick installation. FIG. 11 illustrates a transition joint 75 between a dry cable and an oil-filled cable. The epoxy component may be extended to form an insulator housing 76 on the oil-filled side 77. Advantages are as above,--lower material and installation cost as well as a compact design. In FIG. 12, there is illustrated a joint 78 between two apparatus 79 and 80, e.g. between a transformer and a switching station. Rigid insulators 81 and 82 fastened to the apparatus "e.g." as bushing devices, have conical interface surfaces 83 and 84 corresponding to the interface surfaces 85 and 86 of the connection device 87. This device consists of a connector 88 for electrical conductors, not shown in this Figure, a connector shield 89, an insulating body 90 made of an elastomeric material and covered by a conductive screen 91. This complete device is enclosed within an outer rigid casing 92. For optimizing the products described in the above detailed description and for making sure their high operating reliability in high or extra high voltage installations an essential characteristic is the outer surface configuration of the rigid insulator having the conical interface surface. Therefore, FIG. 13 illustrates a rigid insulator 93, corresponding to the insulator 41 in FIG. 4, to be used in the above embodiments of this invention. The claimed angle is the angle between the longitudinal axis 94 and the boundary surface 95 of the insulator 93. This angle defining the cone of the insulating body should be between 15° and 45°. The above detailed description of embodiments of this invention must be taken as examples only and should not be considered as limitations on the scope of protection.

The present invention aims to obtain a simplified connection system for high voltage power cables having ratings up to 400 KV and above. There is obtained a common cable connection system for all accessories and interconnection. The connection system uses a generally applicable interface (4, 5, 6; 13, 14, 15; 30, 40) for interconnection with a number of different apparatus and includes a cable termination (30) consisting of an elastomeric body (36), integrated therein a stress relief device (34), a connector shield (35), an insulation having a conical interface surface (37) and an outer conductive screen (39) and a rigid insulator (41) having a conical interface surface (42) corresponding to the interface surface (37) of the cable termination (30).

big_patent

THE FIELD OF INVENTION The invention relates to a fixing mechanism for a tool for treatment of a material, such as machining, wherein the fixing mechanism comprises a combination of a tool, its frame and tool holder in the frame of a machine tool. The fixing mechanism according to the invention can be applied in a wide range of technology, including machining by chipping, such as milling, reaming, drilling, turning, etc. of wood, plastics, metal, etc. as the material for machining. The fixing mechanism can be used in various types of robot applications for production, in the exchange of grippers or the like in other automatic devices, such as apparatus for transfer and treatment of pieces, in pneumatic tools, etc., wherein exchange of tools required for different kinds of operations is necessary for carrying out various operations. Further, the above fixing mechanism for a tool is particularly advantageous for use in cutting, punching, moulding and forming work, particularly in machining of metal sheets in so-called sheet machining centers. In machining of this kind, the direction of fixing a tool is a linear movement whereby the machining or forming blade edge directs the machining force to the sheet, usually in a direction perpendicular to the main direction of the sheet, the sheet being placed between the tool and its counterpart, i.e. a cushion. The tool-fixing mechanism according to the invention can be used for fixing both the actual machining tool and its counterpart, i.e. the so-called cushion, to the tool holder in the frame of the machine tool. BACKGROUND OF THE INVENTION According to prior art, it is common to use a so-called conic fit, i.e. a Morse conic fit, for fixing a tool, whereby the tool frame and the tool holder are joined to each other by a fixing movement in their axial direction, the release being effected in a corresponding manner in the axial direction. In particular, the conic fit has the disadvantage that the connecting surfaces very easily tend to be clamped too much against each other, particularly under effect of axial forces. For this reason, many systems presently in use comprise special release mechanisms for releasing clamped conic surfaces in connection with the exchange of a tool. As a natural result, the costs of fixing mechanisms required by tool settings are increased, also, the mechanisms are relatively complex and therefore subject to disturbances during the actual machining operation and particularly during the exchange of a tool. SUMMARY OF THE INVENTION As to the prior art, reference is further made to the publications DE-4218142, EP-22796 and DE-4223158, which disclose tool-fixing mechanisms using interfaces with totally curved surfaces. It is an aim of the present invention to provide an improved fixing mechanism for a tool, wherein the purpose of the invention is to improve the prior art in the field for a wide range of applications. For achieving these aims, the tool-fixing mechanism of the invention is primarily characterized in that at least one of the connecting surfaces in the tool frame and in the tool holder in the frame of the machining tool, extending mainly in the mounting direction, is shaped as a curved surface and that the first contact surface in connection with the tool frame and the second contact surface in the tool holder are adjusted to be placed against each other in the operational position of the fixing mechanism, in order to transmit machining force between the tool frame and the tool holder. Using the solution presented above, a very simple and secure fixing mechanism is achieved. The tool and its frame can be placed in the tool holder by a very simple movement defined by the curved surface, wherein the connecting surfaces are placed substantially against each other and the contact surfaces, extending in a direction substantially perpendicular to the mounting direction, in the final mounting phase transmit the machining force in the mounting direction between the tool, the tool frame and the tool holder and/or transmit the machining force by means of a frictional contact in a direction substantially perpendicular to the mounting direction. Some advantageous embodiments of the fixing mechanism according to the invention are presented in the appended dependent claims. BRIEF DESCRIPTION OF THE FIGURES In the following description, the invention will be disclosed with reference to series of figures shown in the appended drawings and illustrating some advantageous embodiments of the fixing mechanism according to the invention. In the drawings, FIG. 1a shows parts of the tool according to the first embodiment, separate in a cross-sectional view in the mounting direction at the beginning of fixing the tool, FIG. 1b is a cross-sectional view in the mounting direction, showing the stage of mounting the tool and its frame in connection with the tool holder in the frame of the machine tool, FIG. 1c is also a cross-sectional view in the mounting direction, showing the tool, the tool frame, and the tool holder in the frame of the machine tool in the functional position of the fixing mechanism, FIG. 1d shows the stage of releasing the tool and the tool frame in the above-mentioned sectional view, FIGS. 2a-d show another embodiment of the fixing mechanism, corresponding to the stages shown in FIGS. 1a-d, and FIGS. 3a-c show essential stages of FIGS. 1a-d of a third embodiment of the invention. DETAILED DESCRIPTION OF THE INVENTION With reference to FIGS. 1ato 1d, the fixing mechanism comprises as main parts a tool 1, a tool frame 2 for fixing the tool 1, as well as a bushing-like tool holder 3 and clamps 3a. In this embodiment, the tool 1 is a cushion or the like, used as a counterpart for a cutting, punching, molding or forming blade. A connecting element 4 in the tool frame 2 is an inlay with a cylindrical shape. It comprises a first connecting surface 5 extending substantially in the mounting direction and being a straight line in the mounting direction (arrow A), and further a first contact surface 6, i.e. a bottom surface, joining the first connecting surface and being substantially perpendicular to the mounting direction. In the present embodiment, the first contact surface 6 is in a ring-like flange part extending from the first connecting surface 5, from its end facing the bottom of the connecting element 4, towards the center line K of the fixing mechanism, wherein, as shown in FIG. 1c, the central openings KR 2 and KR 3 of both the tool frame 2 and the holder 3 are equal in size and concentric, making any movements of additional parts possible inside the holder 3, in the mounting direction. In the first embodiment illustrated in FIGS. 1a to 1d, the curvilinear connecting surface, particularly a spherical surface, is a second connecting surface 7 in connection with the tool holder 3, extending from a ring-like second contact surface, i.e. a front surface, in a direction perpendicular to the mounting direction A and forming part of the outer surface of the tool holder 3, preferably in the mounting direction. With particular reference to FIG. 1c, the tool frame 2 is arranged to surround the second connecting surface 7 in the end of the tool holder 3, the first 6 and second 8 contact surfaces being against each other. According to the invention, it is advantageous to design the curvilinear surface, i.e. the second connecting surface 7, in a manner that the distance between the radius of curvature r of the curvilinear surface and the center k located on the center line K of the tool holder 3 in the mounting direction and the contact surface, i.e. in the present embodiment the second contact surface 8, fulfills the formula: r.sup.2 =D.sup.2 +d.sup.2, wherein r=the radius of curvature, D=the radius of the second contact surface 8 perpendicular to the mounting direction A, and d=the distance between the center of the radius of curvature and the second contact surface in the mounting direction A. Consequently, a curvilinear second connecting surface 7 is formed, extending from the outer edge of the second contact surface 8 at a distance e from the second contact surface in the mounting direction A, being essentially equal to: e=2*d, wherein d=the distance between the center of the radius of curvature and the second contact surface 8 in the mounting direction A. To make the fixing mechanism function in a compatible manner, the diameter H of the inlay of the connecting element 4 is substantially H=2*r, preferably H=2*r+Δ, wherein Δ is the fit used and wherein r is said radius of curvature. It is obvious that both the cross-sectional form of the tool holder 3 at least by the second connecting surface 7 and the cross-sectional form of the connecting element 4 in the tool frame 2 in a direction perpendicular to the mounting direction A, is a circular form. The used fit Δ can be a clearance fit, an interference fit or a pinch fit according to the use of the tool. FIG. 1b shows the mounting of the tool and its frame 1, 2 in the tool holder 3, wherein the tool frame 2 is moved in an inclined position in relation to the mounting direction A, one edge of the tool holder 3 passing the second connecting surface 7 and drawing the tool frame 2 towards the tool holder 3 by means of clamps 3a fixed in connection with the frame 2 (e.g. groove-nose joint 10a, 10b). The rod-like clamps 3a are thus brought to pass the contact surface 8 in order to fix the groove-nose joint 10a, 10b(FIG. 1a). The tool frame 2 can thus be revolved along the connecting surface 7 forming a spherical curved surface to the position shown in FIG. 1c, where the first contact surface 6 and the second contact surface 8 are in contact with and against each other, ready to receive forces in the mounting direction, the clamp 3a effecting a pressure force between the surfaces 6 and 8, wherein also loads (e.g. torsion) in a direction perpendicular to the mounting direction can be transmitted due to a frictional contact, i.e. F.sub.R =μ*F.sub.K, wherein F R =the radial force, μ=the friction coefficient effective between the surfaces 6 and 8, and F K =the tractive force of the clamp 3a. As shown in FIG. 1 d, the tool frame 2 is released in reverse order by a propulsive force F K by the clamps 3a. It should be noted that in the present embodiment, the depth s of the inlay of the connecting element 4 in the mounting direction A, i.e. the distance between the first contact surface 6 and the ring-like end surface 9 of the tool frame 2, is substantially 2*d, wherein d is the distance between the center K of the radius of curvature r and the second contact surface 8 in the mounting direction A. The clamps 3a, being two or more clamps surrounding the outer periphery of the tool frame 2, comprise a nose 10b provided at their ends and extending in the radial direction towards the tool frame 2. A groove 10a is provided on the outer surface of the frame 2 of the tool 13, surrounding the same and functioning as a mounting element, and having two radial surfaces 11a and 11b, each being in co-operation with the respective radial surfaces 12a and 12b of each nose 10b during mounting of the tool, when it is fixed (11a and 12a in FIGS. 1 a-c) as well as during release (11b and 12b in FIG. 1 d). Alternatively, with reference to FIG. 2, the fixing mechanism according to the invention can be arranged so that a curvilinear surface, seen in a direction perpendicular to the mounting direction, is formed on the outer surface of the tool frame 2, which is spherical substantially in the mounting direction, wherein the connecting element 4 in the tool holder is a corresponding inlay. Naturally, it is possible to shape both connecting surfaces at least partly curved. In the embodiment of FIG. 2, the tool frame 2 comprises a tool fixing element 2a, the tool 1 being fixed on the first surface of the same. The second surface of the plate-like fixing element 2a forms partly the first contact surface 6, against which, in turn, a connecting surface element 2b is fixed, whose surface in the mounting direction forms the curved connecting surface 7. The connecting surface element 2b is placed centrally in relation to the first contact surface 6, wherein the connecting surface element 2b is surrounded by the first contact surface 6 in a ring-like manner. In the mounting direction A, a mounting element 13 extends from the connecting surface element, comprising a central arm 13a substantially in the mounting direction, and an extension element 13b at its free end. The tool holder 3 is at its end provided with a flange-like extension, its end surface forming the second contact surface 8. The tool holder 3 is like a bushing, wherein a clamp 3a is arranged to be movable inside the bushing hole in the mounting direction, receiving a guiding effect from the internal hole of the bushing form of the tool holder 3. The free end of the clamp 3a is provided with an opening-groove system 14, with an opening 14a arranged in the mounting direction to receive the arm 13a of the mounting element 13 as shown in FIG. 2a, wherein the clamp 3a is in the outer position, and the end of the opening-groove system 14 protrudes in the mounting direction A outside the second contact surface 8, wherein the mounting element 13 of the frame 2 can be mounted e.g. from the side in connection with the groove-opening system 14 so that its extension element 13b is placed inside a groove element 14b. The groove element 14b comprises radial surfaces 12a, 12b at the ends of the groove element 14b, perpendicular to the mounting direction A. Thus, according to FIG. 2b, the tool 1 with its frame 2 can be attracted towards the tool holder 3, wherein the connecting surface element 2b is placed inside the bushing form of the holder 3, the inner surface of the same near the end forming thus the second connecting surface 5. The first radial surface 11a of the extension element 13b is at the mounting stage in contact with the first radial surface 12a of the groove element 14. The mounting is effected in a manner presented in connection with blank 1, resulting in a situation shown in FIG. 2c, where in the fixing shown in FIG. 2c, the clamp 3a is driven by a force F K directed upwards, the contact surfaces 6 and 8 being against each other. The tool 1 is released from the holder in a manner shown in FIG. 2d, wherein the second radial surfaces 11b and 12b of elements 13 and 14 are against each other and the force of the clamp 3a effective in the mounting direction removes the contact surface element 2 from the bushing form of the clamp 3a substantially in the mounting direction A. With reference to FIG. 3, the frame 2 is fixed to the clamp 3a by means of a ball mechanism 15 or the like placed in the radial direction inside a series of openings 3b in the clamp 3a, wherein at the starting and releasing stages, shown in FIGS. 3a and 3c, the balls 15a or the like can be placed in inlays 16 in the bushing hole of the holder, being thus moved outwards in the radial direction and making it possible for the extension element 13b of the mounting element 13 to pass the balls 15a in the mounting direction A. In the bushing hole of the holder 3, a bushing-like tube forming the clamp 3a is arranged to be movable in the mounting direction A, wherein the mounting of the frame 2 can be started directly according to FIG. 3a by inserting the mounting element 13, including the arm element 13a and the extension element 13b, in the mounting direction A inside the tube form of the clamp 3a, the balls 15a being in connection with the inlays 16 and thus in their outermost position in the plane of the inner surface of the tube form. When the clamp 3a is moved upwards in relation to the holder 3, as shown in FIG. 3b, the balls 15a are placed inside in a direction perpendicular to the mounting direction A and forced in connection with the radial surface 11a of the extension element 13b by the surface of the inner hole of the holder 3, in order to lock and effect the force F K to the frame 2 in a manner corresponding to that explained above in connection with FIGS. 1 and 2. The frame 2 is released as shown in FIG. 3c by using the face surface 3c of the clamp 3a (corresponding to the radial surface 12b in FIG. 2) to push the contact surface 6 of the connecting surface element 2b which thus forms the second radial surface 11b. The connecting surface 5 in the holder 3 is formed in the connecting element 4 which has a diameter exceeding the bushing hole of the holder 3 where the clamp 3a is movable. Consequently in the embodiment according to FIG. 3, the structure corresponding to the groove-opening system 14 (FIG. 2) is formed to be adjusted in the radial direction according to the movement of the clamp 3a, instead of the solid structure of FIG. 2.

The invention relates to a fixing mechanism for a tool for treatment of a material, such as machining. The fixing mechanism comprises a combination of a tool (1), its frame (2) and tool holder (3) in the frame of a machine tool. At least one of the connecting surfaces (r, 7) in the tool frame (2) and in the tool holder (3) in the frame of the machining tool, extending mainly in the mounting direction, is shaped as a curved surface. The first contact surface (6) in connection with the tool frame (2) and the second contact surface (8) in the tool holder (3) are adjusted substantially in a direction perpendicular to the mounting direction, to be placed against each other in the operational position of the fixing mechanism, in order to transmit machining force between the tool frame (2) and the tool holder (3).

big_patent

CROSS-REFERENCE TO RELATED APPLICATION This application is a continuation of copending, commonly-assigned U.S. patent application Ser. No. 12/004,591, filed Dec. 21, 2007, which is fully incorporated by reference herein in its entirety. BACKGROUND OF THE INVENTION This relates to switching circuitry that may be used to drive display drivers, and particularly to providing switching circuitry that operates at switching high speeds while producing low EMI output. There are various well known techniques for generating supply voltages to display driver circuits. In one instance, for example, a charge pump circuit may be used to act as a high voltage power source for a display driver. In that instance, the charge pump could be configured to first charge a capacitor to a given voltage from a battery. Once charged, the capacitor may be placed in a series connection with the battery to effectively double the output voltage. For example, a 3 volt battery may be used to charge a capacitor, which could then be placed in series with the battery to provide a 6 volt output. Charge pumps often operate at relatively high energy efficiencies, but often don't provide as much current as other methods, such as a switching regulator. For example, typical charge pumps provide energy at power conversion efficiency on the order of about 90%. Another well known technique for providing energy to display driver circuits is to use a switching regulator circuit. In a switching regulator circuit, a switch is used to charge and discharge an active element, such as an inductor, to provide an output voltage. Switching regulators are often used to supply high current, however, such circuits typically generate radiated energy as part of the switching process. The radiated energy is often observed as noise on the circuits surrounding the switching regulator. Switching regulator circuits often produce lower power conversion efficiency, which can be on the order of 80-85% efficiency. Charge pump circuits may provide energy without the introduction of noise, however, that energy is produced at a lower current driving capability due to the large internal resistance of such circuits. This may not be an issue in instances where the display itself is relatively small, such as the display on an Apple iPod Nano product. However, conventional charge pump circuits may not be able to provide the current necessary to drive a larger display, such as the ones used on Apple's iPhone and iPod Touch products. SUMMARY OF THE INVENTION In accordance with embodiments of the invention, methods and apparatus are provided for generating supply voltages for display driver circuits at very high efficiencies and with low quantities of radiated energy (i.e., low noise). In particular, the methods and apparatus are provided to utilize switching regulator circuits that have been modified such that multiple circuit paths are created which carry electric current in opposite directions in order to cancel out the radiated noise of each path. In addition, additional terminal lines are provided which act to sink any electromagnetic interference (EMI) generated in the outermost paths that are actively coupled to the circuit (e.g., the paths in which current flows). Embodiments of the present invention provide the capability to produce relatively large amounts of current, which can be used in driver circuits for relatively large displays such as the Apple iPhone display, without incurring the typical penalties associated with EMI or noise in such implementations. In conventional implementations of chip on glass (COG), an integrated circuit (IC) may be located on one side of the glass used in displays. The IC may include a transistor which operates as the switch in the switching regulator. The transistor may include multiple parallel leads connected to the source and multiple parallel leads connected to the drain. The leads may be connected to a piece of flex circuitry to complete the circuit via circuit elements formed of indium tin oxide (ITO). ITO is particularly useful in display applications because it is a transparent material, but it has a high resistance (it may be on the order of about 10 ohms or so), which can result in a voltage drop of about 500 millivolts. In one embodiment of the present invention, the parallel source and drain paths are configured in an alternating relationship, such that a source path to ground is placed between each two drain paths which are configured to provide the output voltage. In this manner, the EMI generated in the source paths is cancelled by the EMI generated in the drain paths, because the currents through them flow in the opposite direction to each other. In another embodiment of the present invention, the reduction in EMI is more pronounced by the use of a terminal lead (i.e., a lead that is only connected at one end) at the periphery edges of the circuit. The terminal leads act essentially as RF antennas to pick up any leaking fields generated by the last fully-connected paths in the circuit. Various other alternative embodiments are possible. Therefore, in accordance with the present invention, there is provided methods and apparatus for producing sufficient current to drive circuits for relatively large displays, such as the Apple iPhone, which do not generate the electromagnetic interference (EMI) typically associated with such circuits. In addition, the reduction in EMI can be increased through the use of terminal leads. Media player apparatus operating in accordance with the methods and circuits of the present invention are also provided. BRIEF DESCRIPTION OF THE DRAWINGS The above and other advantages of the invention will be apparent upon consideration of the following detailed description, taken in conjunction with the accompanying drawings, in which like reference characters refer to like parts throughout, and in which: FIG. 1 is a schematic diagram of a switching regulator which may be used in accordance with an embodiment of the present invention; FIG. 2 is a timing diagram depicting the operation of a switching regulator such as the switching regulator shown in FIG. 1 in accordance with an embodiment of the present invention; FIG. 3 is a schematic diagram of a conventional implementation of a switching regulator to provide drive current to a digital display in accordance with an embodiment of the present invention; and FIG. 4 is a schematic diagram illustrating various embodiments of the present invention. DETAILED DESCRIPTION OF THE INVENTION FIG. 1 shows a switching regulator circuit 100 that can be implemented in accordance with the principles of the present invention. Switching regulator 100 may include a voltage source 102 that produces a voltage V, an inductor 104 that stores a current I, a diode 106 that prevents energy from the output device from being drained by the switching regulator, and a transistor switch 110 . Diode 106 is coupled to capacitor 108 , which provides the output voltage to the display driver circuit (not shown). As shown, voltage source 102 is configured to be connected between ground and inductor 104 . Inductor 104 may be coupled to both diode 106 and to the drain of transistor 110 to provide operation as described below. The source of transistor 110 is coupled to ground, while the gate of transistor 110 is coupled to a control line. This configuration is commonly known as a boost regulator. FIG. 2 shows a control timing diagram 200 that may be used to show the operation of switching regulator 100 . Timing diagram 200 may include, for example, control trace 202 , which would be the control signal applied to the gate of transistor 110 of FIG. 1 . Timing diagram 200 may also include current trace 204 , which shows the current being conducted by inductor 104 of FIG. 1 . If the current passing through inductor 104 remains constant, there will be essentially no voltage drop across inductor 104 (a negligible drop related to the copper used to form the windings of inductor 104 will occur). Switching regulator 100 may be operated in the following manner. When the control signal 202 is HIGH, for example at time 206 , the voltage on the gate of transistor 110 causes current to flow from the drain to the source of transistor 110 (and then on to ground). Thus, voltage source 102 provides an input voltage to inductor 104 that causes the current flowing through inductor 104 to ramp up, as shown at time 208 in current trace 204 (as shown by arrow 112 in FIG. 1 ). Once the control signal at the gate of transistor 110 switches to a LOW state, as shown at time 210 in FIG. 2 , the switch end of inductor 104 (i.e., the end coupled to diode 106 and to transistor 110 ) swings positive, which causes diode 106 to become forward-biased. This causes current to flow through diode 106 and through capacitor 108 to ground, thereby enabling capacitor 108 to be charged to a voltage that is higher than the voltage of source 102 . Thus, at that time, the circuit follows the path shown by arrow 114 in FIG. 1 . The output voltage V 2 across capacitor 108 may vary slightly as the switch turns ON and OFF. However, the speed at which the switching occurs may result in little variance in the output voltage V 2 . This is why the “efficiency” of switching is so high (90% or higher). While the gate of transistor 110 is in the LOW (or OFF) state, the current flowing from inductor 104 will actually flow to both capacitor 108 , as well as to the load connected to capacitor 108 . In order to limit the current flowing from diode 106 from falling below a certain level, at time 212 , for example, the control signal applied to the gate of transistor 110 switches back to a HIGH state, once again causing the circuit to operate as indicated by arrow 112 in FIG. 1 . During that time, the output load is provided energy solely from capacitor 108 , as inductor 104 is charged back up. FIG. 3 shows one implementation of a switching regulator circuit 300 used to generate direct voltage (DC) for a digital video display (not shown). Switching regulator 300 may include inductor 304 , diode 306 and transistor 310 (elements 304 , 306 and 310 may be similar to those previously described with respect to FIG. 1 ). Instead of using a substance such as copper or gold for the bonding wire, however, it may be preferable to use indium tin oxide (ITO) because it is transparent (which is needed since the circuit is being used to drive a display). ITO, unlike gold, has a relatively high resistance, which can be something on the order of about 10 ohms, but can be as high as 50 ohms or more. In order to reduce the resistance, multiple traces are used for a single switch. For example, by breaking up a signal which would have had a resistance of 50 ohms into four paths, the resistance of each path drops to 12.5 ohms (50 divided by 4). FIG. 3 also shows a series of resistors 320 - 328 that are coupled in parallel between the source of transistor 310 and ground, as well as a series of resistors 330 - 338 that are coupled between the drain of transistor 310 and inductor 304 and diode 306 . Each of these “resistors” is not an actual, physical, resistor that has been coupled into regulator 300 . Instead, each of these resistors represents the resistance of the ITO material that is used as a “bonding wire” in regulator 300 . In addition to the components shown, regulator 300 also includes voltage source 302 and capacitor 308 , both of which operate as previously described with respect to FIGS. 1 and 3 (in which similarly numbered elements were described—e.g., voltage source 102 in FIG. 1 versus voltage source 302 in FIG. 3 ). The division between glass and flex circuitry is shown generally by dashed line 340 , such that the “glass” side is represented by arrow 342 , while the “flex” side is represented by arrow 344 . As generally described above, regulator 300 operates in a manner similar to that of regulator 100 . As the gate of transistor 302 is switched from LOW to HIGH, current flowing through inductor 304 will ramp up causing diode 306 to become reverse-biased (and thereby to act as a blocking diode). Current will continue to flow through parallel “resistors” 330 - 338 , through transistor 310 , and through parallel “resistors” 320 - 328 . When the gate of transistor 310 is switched from HIGH to LOW, current flows directly from inductor 304 through diode 306 (which is then forward-biased), to capacitor 308 , which charges capacitor 308 to a voltage higher than the voltage of voltage source 302 , as well as providing current from inductor 304 directly to the load attached to capacitor 308 . One of the problems associated with the use of regulators like regulator 300 is the relatively large amount of EMI produced by the circuit. This is particularly troublesome in instances where the regulator circuit is being used to drive a display of a device that may be susceptible to such interference, such as a cellular or WIFI communications device (although the EMI problems could, in fact, negatively affect such operations as the playback of audio or video files). In those instances, the interference may cause an unacceptable degradation in the quality of the transmitted and/or received signals that the user's experience becomes virtually intolerable. Alternatively, the generation of EMI may require the hardware designers to implement complicated and potentially expensive solutions to deal with the EMI. These solutions could also potentially add to the overall weight and/or size of the device that the regulator is to be used in. FIG. 4 shows a switching regulator 400 which has been configured to operate in accordance with the principles of the present invention. Switching regulator 400 provides a high efficiency output which is capable of driving relatively large digital video displays with low EMI emissions. The displays can be on the order of the size of, for example, an Apple iPhone of Apple iPod Touch, or even larger. Switching regulator 400 includes voltage source 402 , inductor 404 , diode 406 , capacitor 408 and transistor 410 . Each of these components operates in a similar manner as described above with respect to FIGS. 1 and 3 . In addition, switching regulator 400 includes source “resistances” 420 - 428 and drain “resistances” 430 - 438 which, as described above, are not discrete, physical resistors, but are, in fact, representative of the resistance which occurs from the use of indium tin oxide instead of gold for the bonding wire. The division between the glass and the flex circuitry is generally indicated by dashed line 440 , with arrow 442 indicating generally the glass side, and arrow 444 generally indicating the flex side. Unlike the configuration shown in FIG. 3 , switching regulator 400 produces little to no electromagnetic interference. This is accomplished by configuring the parallel source paths and the parallel drain paths in a specific manner. In particular, in accordance with the principles of the present invention, the parallel source paths are interleaved with the parallel drain paths. For example, drain path 430 is configured to be in between parallel source paths 420 and 422 . Source path 422 is between parallel drain paths 430 and 432 . Drain path 432 is between parallel source paths 422 and 424 , and so on. The interleaving of source and drain paths provides the positive result that EMI produced on one path is substantially cancelled by the EMI produced on one or more adjacent paths. This is illustrated in FIG. 4 by arrows 470 and 472 . Arrows 470 show that, when the control signal applied to the gate of transistor 410 is HIGH (and current is flowing through transistor 410 ), the current through the source paths is flowing downward, from the glass area to the flex area. At the same time, however, the current flowing through drain paths is flowing upward, from the flex to the glass, as shown by arrows 472 . Since the current flowing through a source path should be substantially the same as the current flowing through a drain path, but in the opposite direction, the EMI generated in one path should be substantially cancelled out by the EMI generated in the other path. Operation of switching regulator 400 is similar to the operation described previously with respect to FIGS. 1-3 , except that switching regulator produces significantly less EMI and/or noise than the previously described switching regulators. When the control signal applied to the gate of transistor 410 is HIGH, such that current flows through transistor 410 , EMI produced through the source paths is essentially canceled by the EMI produced through the drain paths, which is traveling in the opposite direction. When the control signal applied to the gate of transistor 410 is LOW, current flows from inductor 404 and does not pass through transistor 410 . Accordingly, little to no EMI is generated in that instance as well. An additional embodiment of the present invention is also shown in FIG. 4 . It may be additionally advantageous, in accordance with the principles of the present invention, to provide two additional paths, shown as dashed components 450 and 460 , to further reduce EMI effects, while maintaining a highly efficient switching regulator. In particular, it may be advantageous to add an additional drain path shown by “resistance” 452 , as well as an additional source path shown by “resistance” 462 . These paths are configured such that they are “terminal” paths, in that they are only connected at one end. Moreover, because of this configuration, there will not be any current flowing through these paths. However, the paths will still operate to pick up any leaking EMI field generated by the adjacent paths. This pick up effect is indicated by arrows 480 and 482 . For example, arrow 480 is shown to be pointing toward the bottom of FIG. 4 , to indicate that it will absorb any counter leaking EMI in the opposite direction as indicated by arrow 472 on path 438 . The terminal paths would only be necessary next to the outer most fully functional paths (i.e., in FIG. 4 , the outer most fully functional paths are shown by reference numerals 420 and 438 ). Thus it is seen that methods and apparatus for producing low EMI energy at levels necessary to drive varying sizes of digital displays are provided. The present invention produces current sufficient to drive relatively large digital displays, such as the touch screen on the Apple iPhone, without generating the negative effects of high EMI radiation. It will be understood that the foregoing is only illustrative of the principles of the invention, and that various modifications can be made by those skilled in the art without departing from the scope and spirit of the invention, and the present invention is limited only by the claims that follow.

Methods and apparatus are provided for generating low EMI display driver power supply. The methods and apparatus include switching circuits that utilize two groups of parallel circuit traces, each of which is coupled to one end of a switching device. The two groups of traces are configured to be interleaved with each other such that no two traces from either group are next to any other traces from the same group. When the switching device is activated, current flows through the circuit and charges an energy storage element. When the switching device is deactivated, the energy storage element discharges a portion of its energy to a second energy storage element and to the driver circuits. In another embodiment, an additional circuit trace is provided which is only connected on one end and is free floating on the other end to capture the majority of EMI remaining that was generated by the switching circuit.

big_patent

BACKGROUND [0001] Vehicle battery rebalancing is performed to correct cell voltage imbalance conditions. For example, the voltage of each of the cells is measured and the cell having the minimum voltage identified. All other cells are bled down via resistive circuitry associated with each cell until the other cells have a measured voltage approximately equal to the minimum. Continuous/periodic cell voltage measurements are taken during the bleed down process to monitor change in the cell voltages. Once all of the cell voltage readings are approximately equal, the battery is charged. SUMMARY [0002] A power system may include a battery having a plurality of cells. The power system may further include at least one controller configured to cause the cells to acquire charge for a period of time such that at the expiration of the period of time, the voltages of the cells are approximately equal. The rate at which charge is acquired by the cells may be different among at least some of the cells for at least a determined portion of the period of time. BRIEF DESCRIPTION OF THE DRAWINGS [0003] FIG. 1 is a block diagram of an alternatively powered vehicle. [0004] FIG. 2 is a flow chart illustrating an algorithm for determining times associated with rebalancing/charging the battery of FIG. 1 . [0005] FIGS. 3A and 3B are flow charts illustrating an algorithm for rebalancing/charging the battery of FIG. 1 . DETAILED DESCRIPTION [0006] Of the total time taken to rebalance and charge a battery, up to 50% of this time (or more) may be dedicated to rebalancing. A plug-in hybrid electric vehicle (PHEV) or battery electric vehicle (BEV) having a 1.5 kw charger and a 6 kwhr battery with cell imbalances (and 1.5 kwhr of energy remaining), for example, may spend 1.5 hours rebalancing the battery and another 3 hours charging the battery (to full capacity). [0007] A PHEV or BEV vehicle owner may desire to minimize the time spent rebalancing and charging their battery. Certain embodiments disclosed herein may provide systems and techniques that attempt to reduce the time spent rebalancing and charging vehicle batteries. Cell Capacity [0008] A battery cell's maximum capacity, Ihr max , may be found according to the relationship [0000] Ihr ma   x = Δ   Ihr Δ   SOC ( 1 ) [0000] where ΔIhr is the change in capacity in the cell and ΔSOC is the change in state of charge of the cell. As an example, the SOC of a given cell may be determined before and after 1 A·hr of capacity is provided to it. Assuming a ΔSOC of 10% for this example, the cell's maximum capacity, Ihr max , would be 10 A·hrs according to (1). Cell Energy Content [0009] A battery cell's energy content, ε, may be approximated from the equation [0000] ε=∫ρ· dt   (2) [0000] where ρ is the power applied to the cell over time. ρ may be written as [0000] ρ= v m ·i   (3) [0000] where v m is the (measured) voltage associated with the power stored and i is the current associated with the power stored. Substituting (3) into (2) yields [0000] ε=∫ v m ·i·dt   (4) [0000] v m may be written as [0000] v m =Δv+V min   (5) [0000] where V min is the voltage of the cell at 0% state of charge (e.g., 3.1 V) and Δv is the difference between the voltage associated with the power stored and the voltage of the cell at 0% state of charge. Substituting (5) into (4) yields [0000] ε=∫(Δ v+V min ) idt   (6) [0000] Δv may be written as [0000] Δ   v = i · v ma   x - v m   i   n Ihr ma   x · t ( 7 ) [0000] where V max is the voltage of the cell at full state of charge, Ihr max is the cell's maximum capacity, and t is the time during which the change in voltage occurs. Substituting (7) into (6) yields [0000] ε = ∫ ( ( i · v ma   x - v m   i   n Ihr ma   x · t ) + V m   i   n )  i   t ( 8 ) [0000] where i is the charger current. Integrating (8) yields [0000] ε = i 2 · v ma   x - v m   i   n Ihr ma   x · t 2 2 + V m   i   n · i · t ( 9 ) [0000] i·t may be written as [0000] i·t=Ihr   (10) [0000] which is the capacity in the cell. Substituting (10) into (9) yields [0000] ε = v ma   x - v m   i   n Ihr ma   x · Ihr 2 2 + V m   i   n · Ihr ( 11 ) Cell Voltage Needed to Provide Specified Energy Content [0010] Assume, for example, that a battery pack includes a string of cells each with a different Amp-hr capacity due to manufacturing tolerances, age, temperature, etc. Also assume that each cell voltage may be approximated by [0000] v cell =( V max −V min )SOC+ V min   (12) [0000] where V max is the voltage of the cell at full state of charge, V min is the voltage of the cell at 0% state of charge (e.g., 3.1 V), and SOC is the state of charge of the cell, or alternatively [0000] v cell = v ma   x - v m   i   n Ihr ma   x · Ihr + V ma   x ( 13 ) [0000] where Ihr max is the cell's maximum capacity, and Ihr is the capacity in the cell. [0011] If all of the cells are charged to the same voltage, each would have a different amount of Amp-hrs stored. The same current would pass through all of the cells during a subsequent discharge of the series string. From (12) or (13), the cells with lesser Amp-hr capacity would begin to have lower cell voltages compared to those with greater Amp-hr capacity. If none of the cells are allowed to discharge below V min , then the cell with the least Amp-hr capacity would determine the end of the allowable string discharge even though some of the cells may still contain useable energy (i.e., SOC>0) if they could be tapped into separately. [0012] Consider that the power provided by each cell, according to (3), is contributing to the total output power of the string. Again if all of the cells are charged to the same voltage, each would have a different amount of Amp-hrs stored. After the first instant of time in which the cells all have the same voltage, the cells with greater Amp-hr capacity will contribute more power and the cells with lesser Amp-hr capacity will contribute less power. The cells with greater Amp-hr capacity, from (2), will contribute more energy to meet the vehicle trip requirements. Hence, if it were hypothetically assumed that all cells had the capacity of the minimum Amp-hr cell and the cells were charged such that the sum of the cells' energy from (9) met the trip requirements, then in the actual string in which some cells have greater Amp-hr capacity, those cells would provide more energy. Less energy would be required of the minimum Amp-hr cell than expected and it would not be fully discharged at the end of the trip (i.e., SOC>0). [0013] Alternatively, if all cells were charged to a voltage based on the maximum Amp-hr cell, then the minimum Amp-hr cell would not have enough Amp-hrs stored in it to allow completion of the trip. Given a final desired discharge voltage at the end of the trip, there is a voltage that all cells must be charged to between that of the minimum Amp-hr cell assumption and the maximum Amp-hr cell assumption. [0014] A method of determining the desired voltage would include calculating the required cell voltage as above using the minimum Amp-hr cell, summing the string energy from (9), and comparing the calculated energy with the required trip energy (which may be determined in any suitable known/fashion based on, for example, trip distance, vehicle design parameters, etc.) If the energy is too great, then an incrementally smaller assumed voltage could be used and the summation process repeated until the desired energy level is reached. A similar process could also be used starting from the cell with the maximum Amp-hr capacity. Battery Pack Charge Time [0015] The target post-charge cell voltage may be determined as described above. From (12), the required SOC for the cells can be determined. If for example V min =3 V and V max =4 V, and the target post-charge cell voltage is 3.5 V, then from (12) the SOC for each of the cells would be 50%. Also, from (12) the initial SOC (the SOC prior to start of charge) can be calculated. The difference between the required SOC and the initial SOC is the required ΔSOC that can be substituted into (1) to determine the ΔIhr required to charge an individual cell. [0016] The time required to charge the battery pack is dependent on: the cell requiring the greatest ΔIhrs, the cell requiring the least ΔIhrs, the method of balancing the cells to the same voltage, and the portion of the charge cycle selected to balance the cells. Consider balancing, for example, by placing a resistor across a selected cell. This can be done during charge resulting in less current passing through the subject cell (current shunted through the resistor) resulting in a lower accumulated cell Amp-hrs or (conventionally at the end of charge) by repeatedly discharging the cells with the higher voltage and then charging the string until all cells are charged to the same voltage. Considering the time required for balancing during charge, the cell requiring the greatest ΔIhrs (i.e., ΔIhr max ) determines the amount of time to charge the battery. In this case, the charge time, t c , is given by [0000] t c = Δ   Ihr ma   x i chg ( 14 ) [0000] where i chg is the charge current rate (Amps). [0017] The time necessary to pass current around a selected cell, t bc , would then be a function of ΔIhr max , the Amp-hrs required of the selected cell, ΔIhr cell , and the magnitude of the shunted current, I shunt , as given by [0000] t bc = ( Δ   Ihr ma   x - Δ   Ihr cell ) I shunt ( 15 ) [0000] If any of the t bc values from (15) is greater than the t c value from (14), the time to charge the string of cells would exceed the actual required time to charge the battery. In that case, a portion of the balancing would need to be done at the end of charge as mentioned above (or at the beginning of charge). Alternatively, the charge current rate could be reduced such that t bc ≦t c . Cell Voltage Balancing to Achieve Target Drive Range [0018] Referring to FIG. 1 , an embodiment of a plug-in hybrid electric vehicle (PHEV) 10 may include an engine 12 , a plurality of cells 13 forming a traction battery 14 , battery charger 15 and electric machine 16 . The PHEV 10 may also include a transmission 18 , wheels 20 , controller(s) 22 , and electrical port 24 . [0019] The engine 12 , electric machine 16 and wheels 20 are mechanically connected with the transmission 18 (as indicated by thick lines) in any suitable/known fashion such that the engine 12 and/or electric machine 16 may drive the wheels 20 , the engine 12 and/or wheels 20 may drive the electric machine 16 , and the electric machine 16 may drive the engine 12 . Other configurations, such as a battery electric vehicle (BEV) configuration, etc., are also possible. [0020] The battery 14 may provide energy to or receive energy from the electric machine 16 (as indicated by dashed line). The battery 14 may also receive energy from a utility grid or other electrical source (not shown) via the electrical port 24 and battery charger 15 (as indicated by dashed line). [0021] The controller(s) 22 are in communication with and/or control the engine 12 , battery 14 , battery charger 15 , electric machine 16 , and transmission 18 (as indicated by thin lines). [0022] Referring to FIGS. 1 and 2 , the controller(s) 22 may determine (e.g., measure, read, etc.) the voltages of each of the cells 13 at operation 28 . At operation 30 , the controller(s) 22 may determine the maximum capacity of each of the cells 13 using, for example, the techniques described with respect to (1). At operation 32 , the controller(s) 22 may determine the common voltage needed for each of the cells to support a target drive range (e.g. 100 miles) using, for example, the techniques described in the section titled “Cell Voltage Needed to Provide Specified Energy Content.” At operation 34 , the controller(s) 22 may determine the charge time for the battery pack 14 using, for example, the techniques described in the section titled “Battery Pack Charge Time.” At operation 36 , the controller(s) 22 may determine each of the cell's resistive circuitry activation time using, for example, the techniques described in the section titled “Battery Pack Charge Time.” [0023] Referring to FIGS. 1 and 3A , the controller(s) 22 may determine, at operation 38 whether the pack charge time determined at operation 34 ( FIG. 2 ) is greater than the maximum of the resistive circuitry activation times determined at operation 36 ( FIG. 2 ). If no, the controller(s) 22 may first balance and then charge the cells 13 of the battery pack 14 at operation 40 using any suitable/known technique. If yes, referring to FIGS. 1 and 3B , the controller(s) 22 may activate, for each of the cells 13 , the resistive circuitry and enable the battery charger 15 at operation 42 . At operation 44 , the controller(s) 22 may determine whether, for each of the cells 13 , the cell's resistive circuitry activation time has expired. If no, the algorithm returns to operation 44 . That is, for any of the cells 13 whose resistive circuitry activation time has yet to expire, the algorithm returns to operation 44 . If yes, the controller(s) 22 may deactivate the cell resistive circuitry at operation 46 . That is, for any of the cells 13 whose resistive circuitry activation time has expired, the controller(s) 22 may deactivate their resistive circuitry. [0024] Once the resistive circuitry for all of the cells 13 has been deactivated, the controller(s) 22 , at operation 48 , may determine whether the battery pack charge time has expired. If no, the algorithm returns to operation 48 . If yes, the algorithm may disable the battery charger 15 at operation 50 . The cells 13 of the battery pack 14 have thus been balanced/charged to a target voltage sufficient to support a desired drive range. [0025] The algorithms disclosed herein may be deliverable to/implemented by a processing device, such as the battery charger 15 or controller(s) 22 , which may include any existing electronic control unit or dedicated electronic control unit, in many forms including, but not limited to, information permanently stored on non-writable storage media such as ROM devices and information alterably stored on writeable storage media such as floppy disks, magnetic tapes, CDs, RAM devices, and other magnetic and optical media. The algorithms may also be implemented in a software executable object. Alternatively, the algorithms may be embodied in whole or in part using suitable hardware components, such as Application Specific Integrated Circuits (ASICs), Field-Programmable Gate Arrays (FPGAs), state machines, or other hardware components or devices, or a combination of hardware, software and firmware components. [0026] While embodiments of the invention have been illustrated and described, it is not intended that these embodiments illustrate and describe all possible forms of the invention. The words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention.

A vehicle may include an electric machine that generates motive power for the vehicle, a plurality of cells that store energy for the electric machine, and at least one controller. The at least one controller may cause the cells to receive current for a period of time and, during the period of time, cause at least some of the cells to supply cell load current such that at the expiration of the period of time, the amount of energy stored by the cells is at least equal to a predetermined target energy level.

big_patent

[0001] This application is a continuation in part of application Ser. No. 11/204,307 filed on Aug. 15, 2005. FIELD OF THE INVENTION [0002] The invention is an AC-to-DC converter as lamp power supply that converts an AC input voltage to a constant DC voltage at predetermined value set by potentiometer. The lamp has constant brightness, no low frequency or high frequency flicker light in the output, no electromagnetic radiation, thus reduce eye's fatigue to minimum level and protect eyesight and health to maximum level. BACKGROUND OF THE INVENTION [0003] Currently, the power supply for lamp has three main categories: 1) Output has only low frequency (less than a few hundred Hz) voltage; 2) Output has only high frequency (more than a few hundred Hz and usually around KHz) voltage; 3) Output has high frequency voltage in low frequency envelope. [0007] The first category has serious low frequency flicker problem, the crystalline lens and pupil muscle will adjust to the flicker light and become very tired. In the long run, the crystalline and pupil muscle becomes slack and can't adjust accurately then myopia is caused. [0008] The second category has high frequency flicker, the crystalline lens and pupil muscle is not fast enough to adjust at such a high frequency. The intense peak light will hurt retina for long run and dry cornea or opacity of the crystalline lens are caused. High frequency electromagnetic radiation will hurt health. [0009] The third category has low frequency flicker to cause myopia and high frequency flicker to hurt retina or cause electromagnetic radiation that will hurt health. SUMMARY OF THE INVENTION [0010] The invention is an AC-to-DC converter as lamp power supply that converts an AC input voltage to a constant DC voltage at predetermined value set by potentiometer. The output lamp has neither low frequency flicker nor high frequency flicker. So the constant brightness light reduces eyes' fatigue to minimum level to prevent myopia. And the constant brightness light can be set to comfortable value that has no intense light to hurt retina by adjusting dimming and feedback circuit. There is no electromagnetic radiation on output. [0011] In order to realize the above object, the invention provides an AC-to-DC voltage converter as power supply for lamp. The converter includes input power supply 210 , input protection circuit 201 , EMI filter 202 , rectifier 203 , filter 204 , converter 206 , output filter 214 , lamp 211 , start circuit 208 , control circuit 209 , biasing circuit 212 , sampling circuit 207 , output protection circuit 200 , feedback and dimming circuit 205 , input monitor circuit 213 . [0012] Input power source 210 is connected to input protection circuit 201 , 201 is connected to EMI filter 202 , 202 is connected to rectifier 203 , 203 is connected to filter 204 , 204 is connected to input of converter 206 , the output of converter 206 is connected to output filter 214 , 214 is connected to lamp 211 , the input of sampling circuit 207 is connected to the output of converter 206 or lamp 211 , the output of sampling circuit 207 is connected to input of feedback and dimming circuit 205 , the output of feedback and dimming circuit 205 is connected to input of control circuit 209 , input of start circuit 208 is connected to output of rectifier 203 or the output of filter 204 , output of start circuit 208 is connected to input of control circuit 209 or output of biasing circuit 212 , input of biasing circuit 212 is connected to output of converter 206 or lamp 211 , input of output protection circuit 200 is connected to output of converter 206 or lamp 211 , output of output protection circuit is connected to input of control circuit 209 , input of input monitor circuit 213 is connected to output of rectifier 203 or output of filter 204 , output of input monitor circuit 213 is connected to input of control circuit 209 , the output of control circuit 209 is connected with converter 206 input. [0013] The position or connection way of circuit Block 200 , 201 , 202 , 203 , 204 , 205 , 206 , 207 208 , 209 , 210 , 211 , 212 , 213 , 214 can be changed, some block can be removed, or new block can be added in or attached. Some block can be integrated into one circuit, part of some block can be integrated with part of another block into one circuit. Every block can use any circuit that has the required function. [0014] In the invention, input voltage source comes from line voltage that is usually low frequency AC voltage such as 110 volt, 60 Hz or 220 volt, 50 Hz; Over current protection circuit becomes open to cut off the connection between voltage source 210 and power supply input when input current is above predetermined value, over voltage protection circuit clamp input voltage under predetermined value to prevent over voltage damage on power supply circuit, they compose input protection circuit 201 ; EMI filter 202 prevents high frequency component from entering low frequency input power supply 210 ; rectifier 203 converts AC voltage to varying magnitude DC voltage; filter 204 prevents high frequency component from entering start circuit 208 and control circuit 209 ; converter 206 converts varying magnitude DC voltage to constant DC voltage; sampling circuit 207 collect voltage signal proportional to output voltage; Feedback and dimming circuit 205 regulates output voltage at constant value while changes output voltage and dims lamp by changing potentiometer resistor value to change the ratio between output voltage and interior reference voltage in control circuit 209 ; control circuit 209 control turn on time or switching frequency of the main switch in converter 206 to regulate the output voltage at a constant value or use other control way such as pulse train control or DSP; Output filter 214 prevents high frequency component from entering output lamp; start circuit 208 supplies power to control circuit 209 to startup the power supply before stable operation, after the power supply enter stable state, the start circuit 208 is reverse biased and doesn't work and biasing circuit 212 supply power to control circuit 209 , some circuit can use biasing circuit 212 to supply power to control circuit 209 from very beginning to stable state; lamp 211 can use any kind of lamp; output protection circuit 200 can have over voltage protection circuit, over current protection circuit, over temperature protection circuit, when output voltage, output current or board temperature is above predetermined value, control circuit 209 turns off the main switch in voltage converter 206 ; input monitor circuit 213 monitor the input voltage and send the signal to control circuit 209 to control duty cycle or frequency response to input voltage in order that the output voltage is regulated at constant predetermined value. BRIEF DESCRIPTION OF THE DRAWINGS [0015] FIG. 1 the block diagram of the invention; [0016] FIG. 2 one implementation of the invention, Flyback topology used as converter 206 , integrated circuit controller IW2202 for control circuit 209 ; feedback is realized with auxiliary winding; [0017] FIG. 3 one implementation of the invention, Flyback topology used as converter 206 , integrated circuit controller IW2210 for control circuit 209 ; feedback is realized with auxiliary winding; [0018] FIG. 4 one implementation of the invention, Flyback topology used as converter 206 , integrated circuit controller IW1688 for control circuit 209 ; feedback is realized with auxiliary winding; [0019] FIG. 5 one implementation of feedback with opto-coupler, R 15 is a potentiometer, R 6 and R 31 are resistors, point 1 is connected to Vo, point 2 is connected to Vref or Vreg, point 3 is connected to Vsense or feedback pin. [0020] FIG. 6 one implementation with DC fluorescent lamp, resistor Rs and Capacitor Cs delay voltage change, Ts is the trigger to connect the cathode filament, after lamp start, voltage goes down and Ts disconnect the cathode filament. DETAILED DESCRIPTION OF THE INVENTION [0021] In FIG. 1 , input voltage comes from line voltage that is usually sinusoidal AC voltage, rectifier 203 converts AC sinusoidal voltage to DC sinusoidal voltage, converter 206 converts DC sinusoidal voltage to a DC constant voltage on output. [0022] FIG. 2 is one implementation of the invention, input power supply 210 comes from line voltage usually around 100 volt 60 Hz AC voltage; Fuse F 1 works as input over current protection circuit, transient absorber VR 1 works as input over voltage protection circuit, F 1 ,VR 1 constitute input protection circuit 201 ; inductor L 2 common mode filter and capacitor C 3 form the EMI filter 202 , resistor R 27 can discharge capacitor C 3 ; diodes D 7 ,D 8 ,D 9 ,D 10 compose bridge rectifier BR 1 , diodes D 15 ,D 16 ,D 17 ,D 18 compose bridge rectifier BR 2 , BR 1 or BR 2 or both become rectifier circuit 203 , resistor R 25 is the limiting current resistor; π filter composed of capacitors C 1 ,C 2 and inductor L 1 works as filter 204 ; transformer T 1 , transistor Q 1 , diode D 20 constitute Flyback topology converter that works as converter 206 , clamp circuit D 2 , diode D 1 , resistor R 24 ,R 26 , capacitor C 15 clamp the spike voltage on the drain of transistor Q 1 , resistor R 30 prevents transistor Q 1 from turning on by static electricity; common mode filter L 3 and capacitor C 20 ,C 30 constitute output filter 214 , resistor R 20 discharge capacitor C 20 ,C 30 ; auxiliary winding of transformer T 1 and diode D 6 constitute sampling circuit 207 ; resistor R 6 ,R 12 and potentiometer R 15 constitute feedback and dimming circuit 205 , capacitor C 21 remove noise signal; integrated circuit Iw2202 works as control circuit 209 , resistor R 29 and diode D 19 control delay time of turn on duration; resistors R 10 ,R 11 ,R 7 , transistor Q 2 , capacitor C 8 , zener diodes D 11 ,D 12 constitute start circuit 208 ; auxiliary winding, diodes D 4 ,D 5 , transistor Q 3 , resistor R 8 , zener diodes D 13 ,D 14 , capacitors C 9 ,C 19 constitute biasing circuit 212 ; lamp 211 can use any lamp such as Halogen, Incandescent or DC fluorescent etc; auxiliary winding, resistors R 16 ,R 17 ,R 23 and diode D 3 constitute output over voltage protection circuit, capacitors C 11 ,C 12 ,C 13 ,C 14 and resistors R 18 ,R 19 ,R 21 , NTC thermistor R 22 and transistor Q 4 constitute over temperature protection circuit, resistor R 9 , filter R 28 , C 18 constitute over current protection circuit, as above, three circuits compose output protection circuit 200 ; capacitor C 16 ,C 17 , voltage divider resistors R 1 ,R 2 ,R 3 ,R 4 , filter resistor R 5 , capacitor C 4 compose input monitor circuit 213 ; the following describes the connection with IC controller Iw2202. [0023] Output of start circuit 208 and output of biasing circuit 212 are connected to pin 1 -Vcc; output of feedback and dimming circuit 205 is connected to pin 2 -Vsense; pin 3 -SCL is secondary current limit feedback input, it is connected to pin 11 -Vrega by a 10 Kohm resistor when secondary current limit is not used; zener diode D 12 of start circuit 208 is connected to pin 4 -ASU by resistor R 7 ; the input monitor circuit 213 get signal proportional to line voltage by voltage divider R 3 and R 4 then sends to pin 5 -Vindc with filter composed of resistor R 5 and capacitor C 4 , monitor signal reflects the average voltage of line voltage and is used as under voltage protection and over voltage protection; input monitor circuit 213 gets signal proportional to line voltage by voltage divider R 1 ,R 2 and sends to pin 6 -Vinac for power factor correction to make current and voltage waveform in phase; resistor R 13 and capacitor C 5 are connected to pin 7 -Vref 2.0 volt reference voltage output; pin 8 -AGND analog circuit ground; pin 9 -SD samples input signal at every switching pulse, when sampling signal is higher than threshold voltage, converter turns off in unlatch mode, it can be used as over voltage protection, over temperature protection; the voltage across R 9 is sent to pin 10 -Isense that is used as main switch current limit, that can be used for single pulse current limit, over current protection or short circuit protection; capacitor C 7 is connected to pin 11 -Vrega that is analog regulator output; capacitor C 6 is connected to pin 12 -Vregd that is digital regulator output; pin 13 -PGND is power ground and grounded; pin 14 -ouput pulse signal to drive transistor Q 1 ; capacitor C 10 is a Y capacitor that is connected between primary and secondary side of transformer. [0024] Another implementation is shown in FIG. 3, 4 respectively, same name component has same function, connection way is similar to FIG. 2 . FIG. 2, 3 , 4 use auxiliary winding as feedback, potentiometer is on primary side; opto-coupler can be used in FIG. 2, 3 , 4 for feedback, potentiometer is on secondary side. One implementation with opto-coupler feedback is shown in FIG. 5 . [0025] The principle of the implementations is as the following: [0026] When main switch Q 1 turns on, the energy is saved in primary winding of transformer, after main switch Q 1 turns off, the energy is transferred to secondary and lamp; [0027] Output voltage Vo, input voltage Vg(t), duty cycle D, D′=1−D, n is the ratio between primary and secondary winding, so Vo=Vg ( t ) *D/ ( D′*n )  (1) Vg(t) is the DC sinusoidal voltage after rectifier 203 , rms value of line voltage is Vrms(t), so w=2*π*f, f is input voltage frequency, Vg ( t )=1.414 *V inrms*|sin(wt)|  (2) Substitute Vg ( t ), we get D ( t )=1/(1+1.414 *V inrms*|sin(wt)|/( n*Vo ))  (3) [0028] From (3), we know duty cycle D(t) an be adjusted according to Vg(t) in order to get constant predetermined value Vo. The frequency also can be adjusted to get constant predetermined value Vo. Pulse Train control or smart skip mode can also be used such as iW2210 or iW1688. [0029] Dimming is realized by changing resistance of potentiometer R 15 , Naux is turns of auxiliary winding, Ns is turns of secondary winding, according to FIG. 2 , Vsense=Vo*R 12 *Naux/((R 6 +R 15 +R 12 )*Ns). [0030] Controller keeps Vsense=Vref. Vo=V ref*(R6 +R 15 +R 12) *Ns /( R 12 *N aux) =V ref*(1+( R 6 +R 15) /R 12) *Ns/N aux [0031] Here Vref, Ns, Naux, R 6 and R 12 are all constant values, R 15 value can be changed. Vo will be changed according to R 15 change. So we can change R 15 value to change output voltage value and also lamp brightness. [0032] In one implementation, power factor correction is realized by adjusting input average current ipr(t)av to be in phase with input voltage Vin(t), power factor is almost 1. [0033] The power supply can be implemented as the following: [0034] Filter 202 , 204 , 214 can use common mode filter, differential mode filter, LC, CLC filter; rectifier 203 can use full bridge rectifier, half bridge rectifier, bridge less PFC etc; converter 206 can use any topology as the following: Buck, Boost, Buck-boost, Noninverting buck-boost, H-Bridge, Watkins-Johnson, Current-fed bridge, Inverse of Watkins-Johnson, Cuk, SEPIC, Inverse of SEPIC, Buck square, full bridge, half bridge, Forward, Two-transistor Forward, Push-pull, Flyback, Push-pull converter based on Watkins-Johnson, Isolated SEPIC, Isolated Inverse SEPIC, Isolated Cuk, Two-transistor Flyback etc; sampling circuit 207 can use auxiliary winding or optocoupler or sampling voltage from the lamp; feedback and dimming circuit 205 can use voltage divider composed of resistor and potentiometer or voltage divider composed of potentiometer and reference voltage; the control circuit 209 in the power supply control suitable topology to convert sinusoidal voltage after rectified to constant DC voltage, Flyback topology can use iW2202, iW2210, iW1688, UCC28600, LNK362, LNK363, LNK364, TinySwitch, TOPSwitch, PeakSwitch, VIPer series, TEA1506,NCP1055,FSDM311,IRIS series etc IC controller; Buck or Buck-Boost topology can use LNK302,LNK304,LNK305,LNK306 etc IC controller;When using other controller or other topology, circuit maybe different from FIG. 2 , circuit 209 can use any controller, IC controller or discrete component controller. [0035] Start circuit 208 can use linear regulator or valley-filled circuit etc; biasing circuit 212 can use auxiliary winding or zener diode; lamp 211 can use any lamp such as Halogen, incandescent, fluorescent etc; input power supply 210 usually comes from 11 volt AC 60 Hz or 220 volt AC 50 Hz. Output protection circuit 200 can have over voltage protection, over current protection, over temperature protection or other protection, it can be realized by other circuit, the power supply can have one or several protection circuits mentioned above. [0036] Many types of method have been described. But all the changes don't run away from main idea. That is the power supply that can convert from low frequency line AC voltage to DC constant voltage which has no low frequency component or high frequency component, which reduces eye's fatigue to minimum level and has no electromagnetic radiation. The invention prevents myopia and protects people's health to maximum level. The invention can be used as bus AC to DC converter, PFC converter, PFC converter for lighting, computer power supply, TV power supply, monitor power supply, notebook adapter, LCD TV, AC/DC adapter, battery charger, power tool charger, electronic ballast, video game power supply, router power supply, ballast, power tool charge power supply etc.

An AC-to-DC voltage converter as power supply for lamp converts an AC input voltage to a constant DC voltage at predetermined value set by potentiometer. The converter includes input power supply 210, input protection circuit 201, EMI filter 202, rectifier 203, filter 204, converter 206, output filter 214, lamp 211, start circuit 208, control circuit 209, biasing circuit 212, sampling circuit 207, output protection circuit 200, feedback and dimming circuit 205 and input monitor circuit 213. This version is a flyback converter; versions from other topologies etc are also provided. The converter has feedback function that can regulate output voltage at predetermined value. The converter has dimming function and can adjust lamp brightness for conformability. The output constant brightness decreases peoples' eyes fatigue to minimum level.

big_patent

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This is a divisional of U.S. patent application Ser. No. 10/804,881, filed Mar. 19, 2004, in the name of Dragan Veskovic and entitled SYSTEM TO CONTROL DAYLIGHT AND ARTIFICIAL ILLUMINATION AND SUN GLARE IN A SPACE, which application claims the benefit and priority of U.S. Provisional application Ser. No. 60/457,276, filed Mar. 24, 2003, entitled MULTI-ZONE CLOSED LOOP ILLUMINATION MAINTENANCE SYSTEM, and U.S. Provisional application Ser. No. 60/529,996, filed Dec. 15, 2003, entitled SYSTEM TO CONTROL DAYLIGHT AND ARTIFICIAL ILLUMINATION AND SUN GLARE IN A SPACE, and is related to U.S. application Ser. No. 10/660,061, filed Sep. 11, 2003, entitled MOTORIZED WINDOW SHADE CONTROL, and U.S. Pat. No. 4,236,101, granted Nov. 25, 1980, entitled LIGHT CONTROL SYSTEM, the entire disclosures of which are hereby incorporated by reference herein. BACKGROUND OF THE INVENTION [0002] The present invention relates to a system to provide sufficient and comfortable lighting within a space. In particular, the invention relates to a system for the automatic control of the light levels in a space by the control of the intensity of electric lighting and/or daylight in a space. In particular, in one embodiment, the present invention is directed to the control of the lighting level in a space, such as an interior room, by controlling both the artificial light in the space by control of the intensity of electric lighting in the space and the control of motorized window treatments in the space in order to achieve a reasonably constant illumination on task surfaces throughout the space. In addition, the invention is directed to a system to reduce or prevent sun glare, which can potentially occur at low sun angles due to sunshine through windows or other openings, e.g., skylights, surrounding the space. Such a condition is likely to occur at or near sunset or sunrise. [0003] Further, the invention is directed to the control of electric lighting in a space in multiple zones of the space to achieve a preset lighting profile in the space. A “lighting profile” represents a desired distribution of target illumination values in various portions of the space. Additionally, the invention is directed to the control of window treatments such as shades based on light levels in the interior of the space so as to maintain a predefined illumination profile in the space and/or to minimize or eliminate sun glare through openings into the space. Further, the invention is directed to a system which performs the three functions of controlling electric lighting in the space, controlling natural lighting in the space in order to achieve a predefined illumination profile and minimizing or eliminating sun glare into the pace. The invention is thus directed to an illumination maintenance system for achieving a predefined illumination profile in a space where the light is provided by natural light or artificial light or both and further where sun glare is optionally minimized or eliminated. [0004] One of the major problems of illumination maintenance systems, and in particular, closed loop (feedback) illumination maintenance systems, is the variation of incident light at the sensor or sensors employed for detecting the incident light due to occupants moving in the space or some other type of variation of surface reflections in the space. One of the prior art approaches to solve this problem is to average the illumination readings from multiple light level sensors. Another approach is to position or orient the field of view of the sensors such that the sensors are not influenced by the occupant traffic or other short or long term variations of the optical properties of the environment. [0005] Further, open loop systems have been developed for illumination maintenance and daylight harvesting but such open loop systems are not suitable for window treatment control implemented based on the interior light sensors because when a shading or window treatment device is closed, access to exterior lighting conditions is prevented or restricted. [0006] Currently available commercial solutions for daylight control of window treatments are mostly based on exterior light sensors and predictive control algorithms. Exterior light sensors cause maintenance problems and require exterior wiring. Predictive control schemes are difficult to configure. Usually a long process of measurements and computer or mechanical model simulations must be performed before the control system can be correctly configured. [0007] Further, a conventional approach that attempts to solve the glare problem due to sunshine entering through windows at a low sun angle utilizes some form of open loop control of window treatments. In these systems, the algorithms are usually based on the use of exterior photosensors. These conventional systems employ a combination of strategies based on the exterior light level readings and a time clock in order to derive the required shade positions. A study of the expected lighting conditions is regularly performed in order to predict the times when the glare incidents are likely to occur. Some of the problems with this type of control are that it demands maintenance of exterior photo sensors exposed to the elements and there are problems with wiring and/or mounting sensors continuously exposed to the outside lighting conditions. Furthermore, preparation and creation of complex databases is required to define the lighting conditions for each space of a building throughout a year for large buildings, which is time consuming and expensive. Further, these systems require control database modifications in case exterior shading objects are added such as new buildings or plants and further, the controls cannot be fully optimized for each space of a large building and therefore do not result in optimal occupant comfort and energy savings. SUMMARY OF THE INVENTION [0008] The present invention provides a new approach to maintenance of illumination in a confined space where the sources of the illumination include combinations of daylight and electric lamps in the space. The space may be divided into illumination zones. The new approach allows for variable and flexible daylight compensation without using separate sensing for each illumination zone and for integrated control of window treatments. One or more sensors can be used to control a plurality of electric lamps in order to reasonably and accurately maintain a desired illumination profile in the space. In addition, a plurality of light sensors can be used to produce a control variable corresponding to the current overall illumination. This approach results in the ability to accurately control local illumination without requiring localized sensing for different parts of the space. [0009] A further advantage of the present invention is that the overall illumination in the space can be maintained for multiple lighting profiles. Each of these lighting profiles can have different requirements for the overall illumination and the relations of illuminations in different portions of the space. [0010] Two exemplary embodiments for the electric light control implementation are described herein, although variations of these embodiments will be apparent to those of skill in the art based on the descriptions contained herein. These embodiments may employ control options defined as “open loop” control and “closed loop” control. The term “open loop” is used to describe an electric light control system based on signals from interior light sensors that predominantly sense daylight entering the space. The term “closed loop” refers to electric light level control systems using interior light sensors which predominantly sense a combination of daylight entering the space and the light generated by the electric light sources being controlled. [0011] The invention also describes a closed loop system for control of window shading devices. It is assumed that such closed loop system is implemented based on the light readings from a light sensor sensing dominantly daylight entering the space through the windows affected by the window treatments being controlled. Therefore the sensor incident illumination changes as a consequence of window treatment adjustment. [0012] Based on one embodiment of the present invention the control of both the plurality of electric lights and window treatments can be achieved using only a single photosensor or a single averaged reading from a plurality of interior sensors. Thus the single signal (single input variable) from a single light sensor or group of light sensors can be used as an input for a closed loop algorithm for control of window treatments and an open loop algorithm for control of electric lights. [0013] As discussed above, one of the problems with prior art systems is that exterior light sensors and predictive control algorithms are employed for control of window treatments. As described above, these systems require maintenance of exterior sensors and complex data gathering and setup procedures. The control approach of the present invention eliminates the need for exterior sensors and these data gathering and setup procedures, thus reducing the overall system cost. [0014] In addition, the present invention also allows sun glare in the interior space to be controlled. The present invention can provide near optimal illumination control of the space. Furthermore, the properties of the space such as the aperture ratios or openings, geometric orientation of the windows or exterior shading objects do not need to be known prior to the installation and commissioning of the system. Both illumination and glare can be controlled without significantly sacrificing energy savings resulting from the use of daylight or interior illumination. The system has the potential to automatically recalibrate based on immediate or repeated occupant input resulting in increased occupant satisfaction. [0015] Another object of the invention is to maximize daylight savings by closing the window treatment only during glare incidents and during times when the sunlight illumination near windows exceeds a preset calibration value. [0016] In this application, it should be understood that “windows” refers to any openings into a space including, e.g., skylights or any other openings. Further, “window treatment” refer to any type of opening shading device, such as blinds, shades, controllable or glazing or any other device whose purpose is to control the amount of light entering or leaving the space through an opening of any kind, whether in a building wall or roof [0017] According to one aspect, the invention comprises an illumination maintenance system for maintaining a desired illumination profile in a space throughout at least a portion of a day, the space being illuminable by both daylight and electric light, the system comprising a sensor for sensing an illumination level in at least a portion of the space; a plurality of dimmable electric lamps providing the electric light to supplement the daylight illumination of the space, the electric lamps arranged in one or more zones in the space, the zones defining predefined volumes of the space, each zone having at least one lamp; a control system controlling the dimming levels of the plurality of electric lamps, the at least one lamp of each zone being controlled to a dimming level to achieve a desired illumination level in the respective zone according to the desired illumination profile and compensate for the daylight illumination in the space throughout at least the portion of the day; wherein the dimming level of each lamp is selected by the control system from one of a plurality of lighting presets, each lighting preset comprising a combination of dimming levels of the lamps, and wherein the control system adjusts the dimming level of the electric lamps toward a preset that will result in an appropriate supplementing of the daylight illumination to achieve the desired illumination profile in the space. [0018] According to yet another aspect, the invention comprises an illumination maintenance system for maintaining a desired illumination profile in a space throughout at least a portion of a day where the illumination sources include daylight and artificial light, the system comprising a sensor for sensing an illumination level in at least a portion of the space, a plurality of electric lamps providing artificial light to supplement the daylight illumination of the space; the electric lamps being dimmable and being arranged in one or more zones in the space, the zones defining predefined volumes of the space, each zone having at least one lamp, a control system controlling the dimming levels of the plurality of electric lamps to maintain the desired illumination profile in the space, the at least one lamp of each zone being controlled to a dimming level to achieve a desired illumination level in the respective zone according to the desired illumination profile, the control system controlling the plurality of electric lamps so that the dimming level of each lamp is adjusted to achieve the desired illumination profile and compensate for the daylight illumination in the space throughout at least the portion of the day, wherein the dimming level of each lamp is selected by the control system from one of a plurality of lighting presets, each preset comprising a combination of dimming levels of the lamps and wherein the control system fades the electric lamps toward a preset that will result in an appropriate supplementing of the daylight illumination to achieve the desired illumination profile in the space; and the control system operating such that, when the desired illumination profile is achieved within a predefined tolerance, the control system stops varying the dimming levels of the lamps. [0019] According to another aspect, the invention comprises an illumination maintenance system for maintaining a desired illumination profile in a space throughout at least a portion of a day where the illumination source comprises daylight entering the space, the system comprising a sensor for sensing an illumination level in at least a portion of the space, at least one electrically controllable window treatment for at least one opening for allowing daylight into the space, the window treatment selectively altering the amount of daylight entering the space through the opening, a control system controlling the at least one window treatment, the control system controlling the at least one window treatment to achieve the desired illumination profile in the space throughout at least the portion of the day, and wherein the control system stops adjusting the at least one window treatment when the desired illumination profile within a predefined tolerance has been achieved. [0020] According to a further aspect, the invention comprises a system for reducing sun glare through an opening into a space, the system comprising at least one electrically controllable window treatment for at least one opening for allowing daylight into the space, the window treatment selectively altering the amount of daylight entering the space through the opening, a sensor for sensing daylight illumination entering the space, a control system controlling the at least one window treatment, and the control system operating to adjust the window treatment in the event of sun glare through the opening to reduce the sun glare, and such that when the sun glare has been minimized, the control system stops the adjustment of the at least one window treatment. [0021] According to yet another aspect, the invention comprises an illumination maintenance system for maintaining a desired illumination profile in a space throughout at least a portion of a day where the illumination source comprises daylight entering the space, the system comprising at least one electrically controllable window treatment for at least one opening for allowing daylight into the space, the window treatment selectively altering the amount of daylight entering the space through the opening, a sensor for sensing daylight illumination entering the space, a control system controlling the at least one window treatment to maintain the desired illumination profile in the space throughout at least the portion of the day, and the control system further operating to adjust the window treatment in the event of sun glare through the opening to reduce the sun glare, and such that when the desired illumination profile within a predefined tolerance is achieved, the control system stops the adjustment of the at least one window treatment. [0022] According to still another aspect, the invention comprises an illumination maintenance system for maintaining a desired illumination profile in a space throughout at least a portion of a day where the illumination sources include daylight and artificial light, the system comprising a first sensor for sensing an illumination level in at least a portion of the space, at least one electrically controllable window treatment for at least one opening for allowing daylight into the space, the window treatment selectively altering the amount of daylight entering the space through the opening, a plurality of electric lamps providing artificial light to supplement the daylight illumination of the space, the electric lamps being dimmable, a control system controlling the at least one window treatment and the plurality of electric lamps to maintain the desired illumination profile in the space, the control system controlling the plurality of electric lamps so that the dimming level of each lamp is adjusted to achieve the desired illumination profile and compensate for the daylight illumination in the space throughout at least the portion of the day, and the control system further operating to adjust the at least one window treatment in the event of sun glare through the opening to reduce the sun glare, and such that when the glare is eliminated or reduced to a satisfactory level and the desired illumination profile within a predefined tolerance is achieved, the control system stops varying the dimming levels of the lamps and the adjustment of the window treatment. [0023] According to a further embodiment of the invention, the illumination maintenance system for an interior space comprises a sensor for sensing illumination in one portion of the space or alternatively for sensing of average illumination in the space, a lighting source to supplement daylight illumination comprising multiple independently controllable dimmable electric lights, and optionally electrically controllable window and/or skylight shading devices to attenuate daylight illumination, for example roller shades, any type of blind or electrically controllable window or skylight glazing. [0024] According to yet another embodiment, the invention comprises an illumination maintenance system for maintaining a desired illumination profile in a space throughout at least a portion of a day where the illumination sources include daylight and artificial light, the system comprising at least one interior sensor for sensing an illumination level in at least a portion of the space; at least one electrically controllable window treatment for at least one opening for allowing daylight into the space, the window treatment selectively altering the amount of daylight entering the space through the opening; a plurality of electric lamps providing artificial light to supplement the daylight illumination of the space, the electric lamps being dimmable; a control system controlling the at least one window treatment and the plurality of electric lamps to maintain the desired illumination profile in the space; the control system controlling the plurality of electric lamps so that the dimming level of each lamp is adjusted to achieve the desired illumination profile and compensate for the daylight illumination in the space throughout at least a portion of the day; wherein the control of the electric lamps is implemented based on an open loop control algorithm and the control of window shading devices is implemented based on a closed loop control algorithm; and wherein the control of both the electric lamps and the window treatments is based on a signal representing a single input variable derived from the at least one interior sensor. [0025] Further, the system comprises an automatic control system operating both the window and/or skylight shading devices and the electric lights in order to maintain a desired illumination profile in the space. [0026] According to a first electric light control method of the invention, the electric lights are controlled using a closed loop algorithm. Preferably, the lighting control system operates the electric lights so that the lights are dimmed between two or more fixed presets or scenes. Each preset comprises a combination of dimming levels to achieve the desired lighting profile and compensate for the daylight availability in the space through the day. The presets are ordered based either on the overall dimming level for each zone or the dimming levels intended for particular portions of the space. The correlation of dimming level of the individual lighting zones for each preset is set in the inverse proportion to the daylight available at a particular position in the space. [0027] The control system automatically adjusts the dimming level of the electric lights towards a preset that would result in the appropriate supplementing of the available daylight. When the desired illumination is achieved, the system stops varying the light output from the electric lights and/or stops varying the position or transparency of the shading devices. The system adjusts a plurality of electric lights between presets corresponding to one or more daytime lighting conditions and a nighttime lighting condition. Both the window shading devices and the electric lights can be controlled using one or more interior photosensors representing a single input to the control system. Alternatively, the window shading devices can be controlled based upon one or more interior photosensors separate from the photosensors used to control the electric lights and connected to a lighting control processor. [0028] The method for control of window treatments described by the present invention can also be combined with an open loop method for control of electric lights. This open loop method for electric light control can preferably be implemented as described in the referenced U.S. Pat. No. 4,236,101, the entire disclosure of which is incorporated by reference herein. [0029] In the case when an independent second photosensor or a set of photosensors are used for the control of the window shading devices, the photo sensors are preferably mounted close to the window such that their field of view is oriented toward the windows such that they dominantly sense the daylight entering the space. [0030] As mentioned, an independent set of photosensors can be used for the control of electric lights. These sensors can be of the same type as the photosensors controlling the window shading device and are in an exemplary embodiment connected to the lighting control system via a separate interface unit. The light level readings from these sensors are processed by an independent control algorithm. The photosensors used for the electric light control are preferably mounted at approximately two window heights away from the windows. In one particular implementation, the sensors are oriented so that their field of view is away from the windows. This orientation is suitable for a closed loop lighting control system. However, dominantly open loop system could also be employed for this purpose. In the case of dominantly open loop control, the field of view of the interior sensors for the electric lighting control is oriented towards the windows. [0031] The invention also comprises methods for illumination maintenance. [0032] According to one aspect, the invention comprises a method for maintaining a desired illumination profile in a space throughout at least a portion of a day where the illumination sources include daylight illumination and electric light illumination, the space containing a plurality of electric lighting zones defining predefined volumes in the space, each zone having at least one dimmable electric lamp, the method comprising the steps of: defining a plurality of lighting presets, each preset comprising a combination of dimming levels of the lamps; sensing an illumination level in at least a portion of the space; and adjusting the dimming levels of the electric lamps toward one of the lighting presets in response to the sensed illumination level in order to supplement the daylight illumination and to achieve the desired illumination profile in the space. [0033] According to another aspect, the invention comprises a method for maintaining a desired illumination profile in a space throughout at least a portion of a day where the illumination sources include daylight and artificial light, the method comprising sensing an illumination level in at least a portion of the space, supplementing the daylight illumination of the space with a plurality of electric lamps providing artificial light, the electric lamps being dimmable and being arranged in one or more zones in the space, the zones defining predefined volumes of the space, each zone having at least one lamp, controlling with a control system responsive to the sensed illumination level the dimming levels of the plurality of electric lamps to maintain the desired illumination profile in the space, the step of controlling comprising adjusting the dimming level of the at least one lamp of each zone to achieve a desired illumination level in the respective zone and thereby maintain the desired illumination profile in the space and compensate for the daylight illumination in the space, wherein the dimming level of each lamp is selected by the control system from one of a plurality of lighting presets, each preset comprising a combination of dimming levels of the lamps and wherein the control system fades the electric lamps toward a preset that will result in an appropriate supplementing of the daylight illumination to achieve the desired illumination profile in the space; stopping varying of the dimming levels of the lamps when the desired illumination profile within a predefined tolerance is achieved, and repeating the above steps during the day to maintain the desired illumination profile throughout at least the portion of the day. [0034] According to another aspect the invention comprises a method for maintaining a desired illumination profile in a space throughout at least a portion of a day where the illumination source comprises daylight entering the space, the method comprising, sensing an illumination level in at least a portion of the space, providing at least one electrically controllable window treatment for at least one opening for allowing daylight into the space, the window treatment selectively altering the amount of daylight entering the space through the opening, controlling the at least one window treatment with a control system responsive to the sensed illumination level to achieve the desired illumination profile in the space, stopping adjusting the at least one window treatment with the control system when the desired illumination profile within a predefined tolerance has been achieved, and repeating the above steps during the day to maintain the desired illumination profile throughout at least the portion of the day. [0035] According to yet another aspect, the invention comprises a method for reducing sun glare through an opening into a space, the method comprising, providing at least one electrically controllable window treatment for at least one opening for allowing daylight into the space, the window treatment selectively altering the amount of daylight entering the space through the opening, sensing daylight illumination entering the space, controlling with a control system responsive to the sensed daylight illumination the at least one window treatment, and adjusting with the control system the window treatment in the event of sun glare through the opening to reduce the sun glare, and when the sun glare has been minimized, stopping adjustment of the at least one window treatment. [0036] According to still yet another aspect, the invention comprises a method for maintaining a desired illumination profile in a space throughout at least a portion of a day where the illumination source comprises daylight entering the space, the method comprising, providing at least one electrically controllable window treatment for at least one opening for allowing daylight into the space, the window treatment selectively altering the amount of daylight entering the space through the opening, sensing daylight illumination entering the space, controlling with a control system responsive to the sensed daylight illumination the at least one window treatment to maintain the desired illumination profile in the space throughout at least the portion of the day, and further adjusting with the control system the window treatment in the event of sun glare through the opening to reduce the sun glare, and when the desired illumination profile within a predefined tolerance is achieved, stopping adjustment of the at least one window treatment, further comprising repeating the above steps during the day to maintain the desired illumination profile throughout at least the portion of the day. [0037] Yet another aspect of the invention comprises a method for maintaining a desired illumination profile in a space throughout at least a portion of a day where the illumination sources include daylight and artificial light, the method comprising, sensing an illumination level in at least a portion of the space, providing at least one electrically controllable window treatment for at least one opening for allowing daylight into the space, the window treatment selectively altering the amount of daylight entering the space through the opening, supplementing the daylight illumination of the space with a plurality of electric lamps providing artificial light, the electric lamps being dimmable, controlling with a control system responsive to the sensed illumination level the at least one window treatment and the plurality of electric lamps to maintain the desired illumination profile in the space, controlling with the control system the plurality of electric lamps so that the dimming level of each lamp is adjusted to achieve the desired illumination profile and compensate for the daylight illumination in the space throughout at least the portion of the day, further adjusting with the control system the at least one window treatment in the event of sun glare through the opening to reduce the sun glare, stopping varying of the dimming levels of the lamps and the adjustment of the window treatment when the desired illumination profile within a predefined tolerance is achieved, and repeating the above steps during the day to maintain the desired illumination profile throughout at least the portion of the day. [0038] Other features and advantages of the present invention will become apparent from the following description of the invention which refers to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0039] The invention will now be described in greater detail in the following detailed description with reference to the drawings in which: [0040] FIG. 1 is a block diagram of a lighting maintenance system according to the invention; [0041] FIG. 2 shows the floor plan of a typical room layout with the system of the invention connected to the various sensors, lighting sources and controllable window treatments; [0042] FIG. 3 is a diagram showing a first example of a preset configuration for a flat lighting profile; [0043] FIG. 4 shows a second example of a preset configuration for a different lighting profile; [0044] FIG. 5 shows a third example of a preset configuration for yet a different lighting profile; [0045] FIG. 6 shows a process flow of the system main loop; [0046] FIG. 7 a shows the process flow for a first system controlling the electric lamps only, when the lighting in the space is too dark; [0047] FIG. 7 b shows the process flow for the first system controlling the electric lamps only, when the lighting in the space is acceptable; [0048] FIG. 7 c shows the process flow for the first system controlling the electric lamps only, when the lighting conditions in the interior space are that there is too much light; [0049] FIG. 8 a show the process flow for a second system controlling both electric lamps and window treatments, when the lighting is too dark; [0050] FIG. 8 b shows the process flow for the second system when the lighting is acceptable; [0051] FIG. 8 c show the process flow for the second system when there is too much light; [0052] FIG. 9 is the process flow of the system showing how the system varies a time delay to operate the window treatments in response to the amount of illumination; [0053] FIG. 10 shows how the system varies the dead-band set point to reduce glare; [0054] FIG. 11 shows an alternative process flow for reducing sun glare; [0055] FIG. 12 shows the process flow in response to a manual override; [0056] FIG. 13 , comprising FIGS. 13 a and 13 b , shows how sun angle is measured; and [0057] FIG. 14 shows graphs of illumination levels and when glare control is needed throughout a day. DETAILED DESCRIPTION OF THE INVENTION [0058] With reference now to the drawings, FIG. 1 is a block diagram of an embodiment of the invention for controlling the illumination levels in a space such as a room, where both daylight and artificial lighting act as light sources, as well as for reducing sun glare. The system 10 comprises a central processor 100 which may be a Lutron GRAFIK 6000® central lighting processor, for example, Model No. GR6MXINP. The central processor 100 has coupled thereto a dimming panel 110 which has various lighting loads 120 which can be any light source type including but not limited to incandescent, fluorescent, HID (High Intensity Discharge), neon, LED (Light Emitting Diode), LV (Low Voltage) coupled thereto and which are controlled by the dimming panel 110 in response to commands from the central processor 100 communicated via a digital communication link 137 . The dimming panel may be a Lutron type GP12-1203ML-15. Photosensor interface 130 is coupled to the central processor via a digital communication link 135 . Coupled to the photosensor interface 130 are one or more photosensors 140 which may be microWATT® photosensors available from Lutron model No. MW-PS-WH. Photosensors 140 are for control of the interior lights 120 . A further photosensor interface 132 is coupled to the central processor 100 via the link 135 . Coupled to the photosensor interface 132 are one or more photosensors 145 which may be microWATT photosensors available from Lutron model No. MW-PS-WH. Photosensors 145 are for control of the motorized window treatments 170 . [0059] One or more wall stations 150 may be provided which are coupled to the central processor 100 as well as the photosensor interfaces via the digital communication link 135 . These wall stations 150 are provided for manual control of the various lighting loads 120 . Also connected to the link 135 may be a window treatment controller 160 for manually controlling the window treatments 170 . This controller 160 may be a Lutron GRAFIK 6000 Sivoia® controller model No. SO-SVCI-WH-EO1. Window treatments 170 may comprise Lutron Sivoia motor drive units, e.g., model No. SV-MDU-20 or Lutron Sivoia QED™ electronic drive units, e.g. model No. SVQ-EDU-20 driving Lutron Sivoia roller shades, Kit no. SV-RS-KIT. [0060] A computer, for example a personal computer 180 may be coupled to the central processor 100 via an interface adapter 190 and suitable connections such as a PC jack 200 for programming/monitoring of the central processor. Note that a Lutron GRAFIK 7000™ central lighting processor could be used in place of the GRAFIK 6000 central processor. [0061] FIG. 2 shows a floor plan of a typical room layout. The central processor 100 and dimming panel 110 are shown located in an electrical closet. The various lamps 120 are also shown and are grouped into, for example, five zones, each zone controlled separately by the dimming panel. Zone 1 is closest to the windows 172 . A different number of zones can be employed, including a single zone. The photosensor interface 130 is coupled to the photosensors 140 and the interface 130 is connected to the central processor 100 . Photosensors 140 are preferably mounted such that there is no or minimal daylight shining directly into the photosensor and so that the photosensor measures the light reflected off the surfaces in the illuminated space. Photosensors 140 are preferably mounted at approximately two window heights away from the windows 172 . The window treatment controller 160 is coupled to the motorized window treatment motors 171 driving the window treatments 170 . The window treatment controller 160 , allows manual control of the window treatments 170 . The Photosensor interface 132 is coupled to a photosensor or photosensors 145 for sensing daylight entering the room and is connected to the central processor 100 . Photosensors 145 are directed so that their field of view is toward the window and are preferably mounted within one window height of the windows 172 . [0062] The central processor 100 manages the lighting for an entire facility and allows the user to create and recall custom preset scenes (or presets) for common room activities, for example, general meetings, audio-video presentations, special events, etc. Scenes are set by adjusting the intensity of each zone of electric lights or motorized window treatments to generate a combination for the particular activity. Wall stations 150 , hand held controls, preprogrammed time clock events, occupancy sensors, and photosensors 140 , 145 can supply inputs to the system to select any scene in any area. The central processor 100 includes an astronomical time clock, which is capable of scheduling events based on sunrise and sunset times. System design and setup are accomplished using, e.g. Lutron GRAFIK 6000 setup software on a personal computer 180 . When system setup is complete, the computer 180 may be used for system monitoring and real time operation. One standard central processor 100 can control up to 512 zones and 544 scenes with up to 96 control points. [0063] The motorized window treatments 170 allow the system to control natural light in addition to electric light. The motors 171 can be programmed to preset window treatment levels. The controller 160 allows for selection of the window treatment presets from the central processor 100 . Up to 64 motors can be controlled for each controller 160 . [0064] The photosensor interface 130 is used for selection of preset lighting scenes and the interface 132 is used to set window treatment levels in response to available daylight or electric light for optimum light levels, energy savings, and reduced sun glare. The photosensor interfaces 130 , 132 process the light level information from photosensors 140 , 145 and transmit this measured illumination data to the central processor 100 via the digital communication link 135 . [0065] In a preferred implementation of the invention, the central processor 100 runs two algorithms: 1) a first algorithm for the control of the window treatments and the second algorithm for control of the electrical lights both based on the readings of photosensors 140 communicated to the central processor 100 through photosensor interface 130 . Alternatively the first algorithm for control of window treatments can be implemented based on the readings of photosensors 145 communicated to the central processor through photosensor interface 132 . Yet another alternative approach is to base the operation of both control algorithms on the readings from photosensor 145 via interface 132 . In this case the control of the electric lights would be based on pre-existing control algorithms as described in U.S. Pat. No. 4,236,101 and implemented in Lutron daylight compensation products such as Micro Watt, Digital Micro Watt and Radio Touch. [0066] In the preferred implementation described, the two algorithms are operated by the same processor. Alternatively, the two algorithms could work independently and be controlled by separate processors or the same processor, but operating independently. For example, one system could be provided to adjust only the shading and to reduce glare in the space. A separate system could be employed only to adjust electrical light levels. Alternatively, one system can handle all three functions, electric light control, shade control to maintain an illumination profile and shade control to minimize sun glare. [0067] In order to control the electric lights according to the first aspect of the invention the implementation is based on a fixed number of presets, or lighting scenes, preferably four presets may be used. However, any number of presets can be provided, including only one. Each preset defines a target intensity for one or more electric lighting zones, for example, zones 1 - 5 shown in FIG. 2 . For a system with four resets, these presets will be referred to as Minimum Preset, Medium Low Preset, Medium High Preset and Maximum Preset. [0068] In most cases, the Minimum Preset is configured so that all electric lights are turned off and is used to maximize daylight in the space. For spaces where daylight contribution deeper in the space is inadequate the minimum preset is configured to maintain adequate illumination under conditions of high daylight availability and with the window treatments fully open. This preset is preferably calibrated when there is adequate daylight availability in the majority of the space being controlled. [0069] The Medium Low preset normally corresponds to the required contribution of electric lights to the overall illumination when enough daylight is available to achieve the highest required illumination in the space in close proximity to the windows or other openings. [0070] The Medium High preset corresponds to the required contribution of electric lights when the available daylight is between the maximum and minimum amounts. [0071] The Maximum Preset corresponds to the required illumination in the space by electric lights only with no daylight available. [0072] The above is one possible way of programming the Minimum, Medium Low, Medium High and Maximum presets, but other values for these presets could be used. [0073] Various preset or scene configurations are shown in FIGS. 3, 4 , and 5 . Each chart shows the electric light and daylight levels versus distance from the window. The dashed lines represent the level of the electric lights, which typically get higher farther from the window. The solid line represents the level of daylight coming in through the window at an instantaneous time in the day, which typically decreases with distance from the window. FIG. 3 is an example of a preset configuration for a flat lighting profile in which the Maximum Preset has all zones at maximum intensity (constant light level is desired across the space). The zones intensities for Medium High and Medium Low presets vary depending on distance from the window, so that zones farthest from the window have their lamps set brighter. FIGS. 4 and 5 show preset configurations, in which the presets have different graph shapes for different lighting profiles. [0074] Average illumination contribution for each of the four presets must provide progressively higher overall illumination as detected by photosensors 140 installed in the space. Light level information from one or more photosensors 140 is processed by photosensor interface 130 , transmitted to central processor 100 , and compared to two thresholds. These thresholds correspond to: 1. The minimum of the acceptable range of illumination; and 2. Target value for the illumination; and 3. The maximum of the acceptable range of illumination. [0078] A light level signal comparator for comparing the light level to the thresholds is preferably of a hysteretic type and can be implemented either as a digital or an analog component. Alternatively, the comparator function can be implemented as part of the central processor 100 . Preferably this comparator should be configurable so that a number of different lighting threshold groups can be selected based on a configuration input. [0079] The resulting information will correspond to the following lighting conditions: 1. Illumination in the area is too dark (below minimum threshold); and 2. Illumination in the area is acceptable (above minimum and below maximum threshold); 3. Illumination in the area is too bright (above maximum threshold). [0083] Based on this information, the central processor 100 controls one or more electric lighting zones to achieve the desired illumination profile. Further, as will be described in more detail below, the system preferably will control the window shading devices to prevent sun glare based on input from the photosensors 145 . [0084] As discussed above, in the exemplary embodiment there are four presets, Minimum, Medium Low, Medium High and Maximum. The following paragraphs describe the steps taken to configure these four presets. [0085] The calibration of the presets is performed with the control algorithms in the processor 100 disabled and the system is under manual control only. The Minimum Preset is configured by setting the electric light levels when a high level of daylight illumination is available dominantly exceeding the desired target illumination in the space. Lighting zone intensities for the zones closer to the windows are set to off for the Minimum Preset. [0086] The Medium Low Preset is configured as follows: The central processor 100 is disabled and set to a manual control. With the electric lights off, the window treatment positions are selected such that the daylight illumination in the area around the middle of the room or under the second row of lights for deeper spaces is at the target level. Thereafter, the levels of all electric light zones are set such that the light level in the entire area is acceptable. This configuration is the Medium Low Preset. [0087] To configure the Medium High Preset, the central processor 100 is disabled and set to manual control. Medium High Preset in conjunction with the Medium Low Preset defines a region of linear electric light response to daylight availability. This preset is adjusted such that a fixed increase of lighting intensity is added to all of the zone intensities as calibrated for the Medium Low Preset in such a way that no zone intensity exceeds the settings for the night time zone as calibrated in the next step. To simplify calibration the Maximum preset can be calibrated first. [0088] The Maximum Preset is configured by first disabling the control system by setting it to manual control. If blackout window treatments are installed, the window treatments are closed fully, otherwise it is preferable to wait until evening when there is no daylight to set the maximum preset. The levels of all zones are set such that the light level of the entire area will be acceptable with no daylight through the window (nighttime level). This will define the Maximum Preset. [0089] FIG. 6 shows a preferred implementation for the main loop process flow for a system according to the invention based on the closed loop control method for control of electric lights. The main loop will be substantially the same for a system that controls only the electric lamps as it will be for a system that controls both lamps and window treatments. FIGS. 7 a , 7 b and 7 c describe the process flow for a system controlling only the electric lamps. FIGS. 8 a , 8 b and 8 c describe the process flow for a system controlling both the electric lamps and the window treatment devices to achieve a desired illumination profile. FIGS. 9-14 explain the process flow for a system that seeks to reduce or eliminate sun glare. The various loops shown in FIGS. 6-8 c as well as FIGS. 10-12 run continuously or at regular intervals. [0090] FIG. 6 shows the flow chart for the main control loop with the three conditions shown: too dark 500 , acceptable 510 , and too light 520 . If it is too dark ( 500 ), flow is into FIG. 7 a beginning at A. If the level is acceptable ( 510 ), the flow is to FIG. 7 b at B and if there is too much light ( 520 ), the flow is to FIG. 7 c at C. For each decision in FIG. 6 , the light level as sensed by photosensors 140 is compared to one of the two thresholds previously described. [0091] FIG. 7 a shows the flowchart for the too dark condition ( 500 ). In more detail, the controller first checks at 630 to determine if the system is set at the Minimum Preset. If yes, the Medium Low Preset is selected at 640 . If not, a check is made to determine if the system is set to the Medium Low Preset ( 650 ). If yes, a check is made to determine if the electric lights are being faded ( 660 ), that is, still in the process of reaching the particular preset level. If yes, an exit is made back to the main loop ( FIG. 6 ). If fading (dimming level change) has been completed, the Medium High Preset is selected ( 670 ). [0092] If the Medium Low Preset was not set at step 680 , the system checks for whether it is set to the Medium High Preset. Fading is checked at 690 , and if fading is completed, the Maximum Preset is selected at 700 . [0093] If the system is not set at the Medium High Preset ( 680 ), a check is made to determine if it is at the Maximum Preset ( 710 ), still fading ( 720 ), done fading ( 730 ), and the Maximum Preset is selected at 740 and then an exit is made. If the system was not at Maximum Preset at step 710 , the Maximum Preset is set at 750 and an exit is made. Thus, if the Maximum Preset was determined to be the system status at step 710 , and if fading of the lighting at 720 , 730 to the Maximum Preset does not result in the desired illumination, the maximum preset is set at 740 . If the system status at step 710 was that the Maximum Preset (nor any of the other three presets) was selected, the system selects the maximum preset at step 750 . Thus, if selecting and fading to any of the four presets does not result in the desired illumination profile, the Maximum Preset is automatically selected at 750 , as this is the maximum artificial lighting illumination that can be achieved. [0094] FIG. 7 b shows the flowchart for the acceptable lighting condition. As shown, if the illumination is in the acceptable range (as detected by each Photosensor 140 —the measurements of the photosensors 140 can be averaged or the thresholds for each photosensor can be different), the fading is stopped and delay times reset ( 760 ) and return is made to the main loop. [0095] FIG. 7 c shows the flowchart for the too light condition. [0096] At 830 , a determination is made if the system is at the Maximum Preset. If yes, the Medium High Preset is selected at 840 and an exit is made. [0097] If the Maximum Preset was not set at 830 , a check is made to determine if the system has been set at the Medium High Preset at 850 . If so, a check is made to determine if the lights are still fading at 860 . If not, the Medium Low Preset is selected at 870 . If the lights are still fading, an exit is made. Once the Medium Low Preset is set, an exit is made. [0098] If at step 850 the Medium High Preset was not set, a check is made to determine if the Medium Low Preset is set at 880 . If so, a check is made at 890 to determine if the lights are still fading. If yes, an exit is made. If not, the Minimum Preset is selected at 900 and an exit is made. [0099] If at step 880 the Medium Low Preset was not set, a check is made at 910 to determine if the system is set to the Minimum Preset. If yes, a check is made at 920 to determine if the lights are still fading. If yes, an exit is made, if not a check is made at 930 to determine if fading is complete. If yes, an exit is made. If not the Minimum Preset is selected at 940 and an exit is made. [0100] Finally, the Minimum Preset is selected at 950 if an acceptable lighting condition was not determined by the main loop ( FIG. 6 ) at any other point during the steps shown in FIG. 7 c. [0101] Thus, the system operates by constantly operating in a main loop ( FIG. 6 ), leaving the main loop, depending on whether the lighting condition is too dark or too light ( FIGS. 7 a and 7 c ), constantly alternating between the main loop and the loops of FIGS. 7 a and 7 c while cycling through the loops of FIGS. 7 a and 7 c , and once an acceptable lighting condition is realized during the main loop at 510 , stopping fading at step 760 ( FIG. 7 b ). Should an acceptable lighting condition not be realized, the system defaults to the Minimum or Maximum preset, depending on whether the condition was too much light or too dark, respectively. [0102] In order to compensate for the difference in the spectral sensitivity of the photosensors 140 for different types of light sources, the set point thresholds for the electric light control process flow are preferably varied. Due to the narrow frequency spectrum of the light produced by fluorescent lamps, even sensors designed with human eye corrected spectral sensitivity such as the Lutron MW-PS photosensors deliver a lower output signal for fluorescent lighting compared to that produced in the presence of equivalent daylight. [0103] The set points for the electric light control process flow are adjusted based on the output control signal. Based on experimental measurements, the MW-PS photosensors feature around 30% lower sensitivity to fluorescent lighting compared to daylight. This difference does not present a problem in the usual open loop applications but must be corrected in closed loop applications. The sensitivity compensation is implemented such that the set point is proportionally scaled between 0% and −30% when the control signal for the electric lights near the windows changes from 100% to 0%. [0104] One possible implementation of this set point formula is as follows: [0105] Light Set point=Daytime Set point×(1−0.003×Window Lighting Zone Intensity in %). The constant 0.003 is derived from the known fact that the MW-PS Photosensor has 30% lower sensitivity to fluorescent lighting. [0106] The set point can also be adjusted based on the time of day. Since the window treatments are automatically controlled, the overall variation of the daylight availability in the space during the day is significantly reduced. Therefore, the spectral sensitivity compensation will only effectively be required near sunset and sunrise and can be derived based on the sun angle for a given astronomic time clock reading. An astronomic time clock is contained within the central processor 100 . [0107] One example of the alternative method of implementing the selection of the “too dark” and “too light” thresholds is to transmit the current time of day or the Window Lighting Zone Intensity from the central processor 100 to the photosensor interface 130 . The photosensor interface 130 can then make any appropriate adjustments to the set point, process the light level information from the photosensors 140 , compare the light level information to the set point, and transmit a signal to the central processor 100 corresponding to the current light condition, either “too dark” or “too light”. The central processor 100 can then act accordingly to either of these conditions. [0108] The process flow for setting the electric light source levels has thus been described. A further process flow for controlling the window treatments in conjunction with the electric lights will now be described. [0109] Turning to FIG. 8 a , it is substantially the same as FIG. 7 a , with the exception that an additional set of conditions is checked at steps 610 and 620 . In particular, at step 610 , a check is made to determine if the window treatments, for example, shades, are in the manual mode, that is overridden by manual control via wallstation 150 or window treatment controller 160 . If yes, the manually set position is not changed and the process goes to step 630 , previously described. The remainder of the process has already been described with reference to FIG. 7 a , and will not be repeated here. Thus, the system attempts to achieve the desired illumination profile leaving the window treatments as manually set. [0110] If the shades are no longer in manual mode, the step 620 is performed and a check is made to determine if the shades are fully open. If yes, the process flows again to step 630 , and the system attempts to achieve the desired illumination profile so as to maximize daylight (the shades are left in the open position) and minimize electrical energy usage. [0111] If the shades are not fully open, the system begins to open them at 625 , exits to the main loop and returns to the flow of FIG. 8 a as many cycles as necessary until the shades are fully opened, as determined at step 620 , in which case the process flow is to step 630 , where the electric lamps are then controlled. [0112] FIG. 8 b is similar to FIG. 7 b , but shows that in a system controlling window treatments and lamps, when the lighting is acceptable, the adjustment of the window treatment is stopped ( 755 ), the fading of lights is stopped ( 760 ), and the shades are fully opened ( 770 , 775 ), maximizing the amount of daylight in the space and minimizing electric power usage. In another embodiment, it may be desirable, using a time clock, to either fully close or fully open the window treatments after dusk since there is no daylight and to address other concerns such as but not limited to privacy, aesthetic appearance of the building or nighttime light pollution. [0113] FIG. 8 c corresponds to FIG. 7 c , except it shows the process flow for a system controlling lights and window treatments. Similarly to FIG. 8 a , a check is made to determine if the shades are in manual mode at 810 , fully closed at 820 (because there is too much light, as opposed to too much darkness) and begins closing the shades at 825 . The remainder of the flow chart is similar to FIG. 8 c and need not be discussed in detail again here. [0114] There has thus been described a first system (FIGS. 6 to 7 c ) for controlling only the electric lights, based on whatever daylight is present, without adjusting window treatments and a second system controlling both lights and window treatments ( FIGS. 6, 8 a to 8 c ). A system to control only the window treatments, based on the flow of FIGS. 6, 8 a to 8 c , could also be provided. In such a system, the system would control the window treatments based on the available daylight. [0115] Yet a further process flow of the preferred implementation describes an alternative control algorithm which, in addition to controlling diffused daylight illumination near windows, also controls the window treatments to minimize or eliminate sun glare based on the readings of photosensors 145 through photosensor interface 132 . [0116] In order to prevent glare when the sun is at a low angle, for example, near sunset or sunrise, the system of the invention automatically controls the window treatments 170 to prevent glare. In an exemplary embodiment, for aesthetic reasons, the window treatments 170 are preferably controlled in such a way that only a set number of fixed stationary window treatment positions or presets is allowed. For example, the window treatments 170 may move between 4 to 5 fixed window treatment presets including fully opened and fully closed. The control is implemented in the form of closed loop control with a dead-band. This control is not, however, limited to a discrete control. The control could be continuous, as previously described, or it could have more or fewer than 4 to 5 window treatment presets. [0117] The term “dead-band” is used to describe a range of photosensor 145 incident light level readings, which are considered by the system as acceptable and for which no action is performed other than to reset the window treatment delay timers. This will be described below. [0118] The system will only change the window treatment settings when the incident light level on photosensors 145 is outside of the dead-band. In order to reduce the frequency of window treatment movements, all commands are delayed. Therefore, if the particular lighting condition is only temporary, no action will take place. However, glare control is a desirable capability of the system. Therefore, the system should respond quickly when a severe glare condition exists. Longer delays can be permitted when insufficient light is available because the electric lights in the space can compensate for the temporary low daylight availability. [0119] In order to address the above variable timing, i.e., delaying window treatment changes for temporary conditions while responding to severe glare conditions quickly, the system employs a low sampling rate numerical integration of the light level error. When the incident light level seen by the photosensors 145 is out of the range defined as the dead-band, the difference between the upper or lower limit of the band and the actual light level is numerically accumulated. As shown in FIG. 9 , at 1000 and 1010 , the light level is checked to determine if it is higher than the upper limit or lower than the lower limit and thus outside of the dead-band. If it is within the dead-band ( 1015 ), a delay timer accumulator is reset ( 1017 ) and an exit made. If the light level is higher than the upper limit, control is to 1020 ; if it is lower than the lower limit, control is to 1220 . In either case, when the light level is outside the dead band, the actual light level is numerically accumulated as shown at 1040 and at 1240 . When the accumulated sum exceeds predefined limits, the window treatments are moved in order to bring the light level within the dead-band. The actual timing thresholds are different depending on the sign of the error. As mentioned above, the response time for the high illumination condition is shorter than the response time for the low illumination condition. Time delays are reduced in case of consistently low or consistently high sunlight illumination. [0120] In more detail, if the light level is higher than the upper limit of the dead-band, at 1020 the previous light level is compared to the lower limit to determine if it was previously below the lower limit. In such case, the difference between the upper and lower limits is adjusted at 1030 to reset the lower limit. If the light level was not previously below the lower limit, or after the adjustment at 1030 , the difference between the light level and the upper limit is accumulated, thereby resulting in a delay ( 1040 ). [0121] At 1050 , the previous light level is compared to the upper limit. If the previous light level was also above the upper limit, a shorter timing threshold 1060 is employed. This indicates a persistent high light level condition. If the previous light level was not above the upper limit, a longer timing threshold 1070 is employed. As stated above, the time delays are reduced in the case of consistently high sunlight illumination. At 1080 , the accumulated difference between the light level and the upper limit is checked to determine if it is greater than the current timing threshold set at 1060 or 1070 . When the accumulated difference exceeds the timing threshold, the shade is moved to the next more closed preset as indicated at 1090 . At 1100 , a flag is set to indicate that the previous light level was above the upper limit as determined at step 1050 , for the next cycle. [0122] If the light level was lower than the lower limit as indicated at 1010 , a similar process flow 1220 , 1230 , 1240 , 1250 , 1260 , 1270 , 1280 , 1290 and 1300 is employed. However, in this process flow the accumulated difference is between the light level and the lower limit. Similarly, a shorter timing threshold is used if the previous light level was below the lower limit (consistently low sunlight illumination). As discussed above, the response time for consistently high or low illumination conditions is reduced. Time delays are reduced in the case of consistently low or consistently high sunlight illumination. This is indicated at 1060 for the consistently high sunlight condition and at 1260 for the consistently low sunlight condition. [0123] In order to correctly address the glare control problem, the window treatment control process flow employs a variable control setpoint or threshold. When the sun angle is low, the sunlight intensity drops but the likelihood of a glare incident increases. This is because the sunrays become nearly horizontal and can easily directly penetrate deeply into interior spaces. Spaces with windows facing directly east or west are especially susceptible to this problem since they get a direct sun exposure at very low sun angles, at sunrise and sunset, respectively. [0124] The reduction of sun intensity early and late in the day can be expressed as a sinusoidal function of the sun angle above horizon multiplied by the atmospheric attenuation factor. [0125] As is well known to those experienced in the art, based on the fact that the sun is substantially a point source, the sun illumination is Ev=dF/dA=I*cos γ/r 2 . [0000] Where: [0000] γ is the sun angle in respect to direction perpendicular to the surface; I is luminous intensity; r is distance from the source; F is luminous flux; A is area. [0131] Based on simple trigonometry it can be determined that the sun illumination on a horizontal task surface is a sinusoidal function of the sun angle above the horizon. The atmospheric attenuation factor varies with pollution and moisture content of the air and these factors also affect the extent of perceived glare but can be neglected when determining how much the set point needs to be varied. Based on experiments, it can be concluded that variation of the control set point based on the sun angle alone produces satisfactory glare control performance. The central processor 100 features an astronomic time clock so the sunrise and sunset times are available. The window treatment process flow set point is therefore varied indirectly based on the astronomic time clock readings. In an average commercial building the correction is only required during a limited interval of time approximately three hours after sunrise and three hours before sunset. A set point correction factor based on the sinusoidal function of the predicted sun angle gives good practical results. The correction factor can also be implemented in a digital system based on a lookup table directly from the astronomic time clock reading. [0132] For small sun angles, a linear approximation of the sinusoidal function can be applied, that is, since sin α˜α, where angle α measured between the earth's surface and the sun's inclination above the surface. [0133] According to the invention, two alternative methods for calculation of set point correction to control interior illumination and glare are described below. The symbols used are: LSCF=low sun angle correction factor; CTM=current time in minutes; TSSTM=today's sunset time in minutes; TSRTM=today's sunrise time in minutes; CI=predefined correction interval after sunrise and before sunset expressed in minutes (CI is typically 120-180 min depending on the window height and proximity of furniture to windows); NTSR=night time photosensor reading resulting from electric lights only; NTUT=night time upper threshold derived from night time sensor reading (value influenced by electric lighting only)—by default this can be set to 20% above the NTSR; NTLT=night time lower threshold—preferred value is 10% above NTSR to ensure that window treatments remain open after sunset. Lower values may be selected, for instance, to ensure that the window treatments remain closed after sunset for privacy; CUTHR=sun angle corrected upper threshold of the dead-band; CLTHR=sun angle corrected lower threshold of the dead-band set point; DTUT=upper threshold set point; DTLT=lower threshold set point; TARGET=target set point (preferably half way between LTHR and UTHR); PSR=actual photosensor reading; CPRS=corrected photosensor reading. The following algorithm was successfully applied: If (current time is within the predefined correction interval CI before sunset) LSCF=(TSSTM−CTM)/CI Else if (current time is within the predefined correction interval CI after sunrise) LSCF=(CTM−TSRTM)/CI Else LSCF=1 CUTHR=(DTUT−NTUT)*LSCF+NTUT CLTHR=(DTLT−NTLT)*LSCF+NTLT [0149] Alternatively the sensor (Photosensor) gain can be changed based on astronomic time clock readings to achieve an effect equivalent to lowering the thresholds: [0000] If (current time is within the correction interval before sunset) LSCF=(TSSTM−CTM)/CI Else if (current time is within the correction interval after sunrise) LSCF=(CTM−TSRTM)/CI Else LSCF=1 CPSR=PSR*DTUT/((DTUT−NTUT)*LSCF+NTUT) [0150] Based on the above, it can be seen that during the correction interval after sunrise and before sunset, a linear approximation of the sun correction factor is made by dividing the time difference (in minutes) between sunrise (or sunset) and the current time during the correction interval by the correction interval. This results in a good approximation of the correction factor. This is illustrated in FIG. 14 , which shows the two glare control intervals A (sunrise) and B (sunset). It can be seen that the target illumination is bounded by lines having slopes. The instantaneous value of these lines represents the correction factor at a particular time during the glare control intervals. Note that for the preferred embodiment, a correction interval of 180 minutes is used. [0151] The default set point (before correction) is manually set during calibration based on the desired illumination in the space in front of the windows. Therefore the functions of illumination maintenance and glare control can be integrated in a single control algorithm. These variable target illumination values are preferably set such that they are, during the likely glare interval, below the sinusoidal curve representing the vertical daylight illumination variation on a clear day and above the sinusoidal curve representing the variation of vertical illumination on a cloudy day. This allows the algorithm to differentiate between the clear sky condition and the overcast condition. [0152] Based on the astronomic timeclock, the system at night time automatically detects and updates the component of the photosensor 145 reading caused only by the electric lighting. This component is preferably further subtracted from the daytime reading of the light sensor to determine the component of the sensor signal caused only by daylight. [0153] Two alternative ways to correct for the decrease of illumination with the sun angle which have essentially the same effect are thus described above. As discussed, since the incident illumination drops with the sun angle either the dead-band thresholds can be reduced for low sun angles above the horizon or alternatively the photosensor gain can be increased and the midday dead-band thresholds maintained throughout the day. [0154] FIGS. 10 and 11 show the process flow for the above sun angle correction algorithms. FIG. 10 shows one embodiment and FIG. 11 shows the above described alternative embodiment. Turning to FIG. 10 , this figure shows how the system varies the dead-band set point or threshold in order to reduce glare, as described above. If the current time, as determined by the astronomical time clock is either within the correction interval before sunset ( 1300 ) or after sunrise ( 1310 ), the low sun correction function is adjusted at 1320 , 1330 . If the time is not within the correction interval, the correction factor is set at 1 ( 1340 ). At 1350 the dead-band thresholds are corrected by the correction factor. The light levels are then processed based on the new dead-band thresholds. [0155] FIG. 11 shows the alternative embodiment where the photosensor gain is increased. It is identical to the flow of FIG. 10 , except step 1352 is substituted for step 1350 of FIG. 11 . At step 1352 , the photosensor light reading value is divided by the correction factor to increase the photosensor value and the light reading, as corrected, is processed. Accordingly, in FIG. 10 , the dead-band thresholds are adjusted and in FIG. 11 , the photosensor readings are adjusted (by increasing them). [0156] Since the window treatments must also be able to be controlled manually, the system must be able to account for manual overrides, i.e., when a user manually adjusts the window treatment. A manual override introduces a serious problem in a closed loop window treatment control system. Once the manual control command is executed, the interior illumination may exceed the range defined by the dead-band of the control process flow and the system would automatically cancel the override. This obviously is undesirable. To address this problem, the process flow readjusts the control set point after an override. Once the window treatments have stopped moving after a manual override, the process flow temporarily adjusts the control set point to match the currently measured interior light level. The newly established light level is also preferably copied into another variable used to establish the long term preferences of the occupants. During the low sun angle correction interval, previously described, the temporary override set point thresholds are corrected in exactly the same way as in the case where no manual override has been applied. [0157] The temporary control set point can be canceled either based on the daylight exceeding the bounds of the predefined dead-band established by the temporary set point or based on a predefined time delay after an override or both. Once the override is canceled, the control system reverts to the default set point. [0158] The system can optionally adjust the default set point based on repeated occupant input. As stated above, each time an occupant performs a manual override, the newly established light level when the window treatments stop moving is further processed. The processing can be based on averaging the override light level either continuously or based on the time of day for instance only during the time interval when the sun glare is likely to occur. Once the long term average tendency is identified, the system can make an adjustment of the default control set point to the usual or most likely user override. [0159] FIG. 12 shows the process flow in the event of an override. At 1400 the system checks to determine if a manual override is currently applied. If so, at 1410 the system determines whether the shades are still moving as a consequence of the override. If yes, the system exits to return to the main loop. Once the shades stop moving, the system stores the current light level as a target set point for the control process at step 1420 . At 1430 , the system averages the override target level over time in order to change the default set point based on occupant input and at 1440 sets the flag to indicate that the setpoint has been manually overridden. [0160] If a manual override is not currently applied, as determined at 1400 , the system checks at 1450 to determine if it is operating with a modified setpoint due to a previous manual override. If yes, the system checks at 1460 to determine if the modified upper or lower limit has been exceeded. If no, the system exits to the main loop. If yes, at 1470 the system determines if it is consistently overridden through a similar override set point. If yes, the system at 1480 modifies the default target light level toward the consistently used override level. If the system is not consistently overridden or after the modification at step 1480 , the system reverts at 1490 to the default setpoint for the target light level, clears the manual override flag and exits to the main loop. [0161] FIGS. 13 a and 13 b shows the relationship between the sun angle and the direct sun penetration into the space. FIG. 13 a shows how at low sun angles the direct sun rays penetrate deeper into the space and affect the task surface basically representing a glare condition. FIG. 13 b shows the absence of direct incident sun rays on the task surface associated with larger sun angles. [0162] FIG. 14 graphically shows the daylight illumination variation of the vertical daylight illumination throughout a day for two conditions (clear and overcast), the variation of target illumination and the time intervals A and B when glare control is needed and where the target illumination is corrected to account for the reduction of illumination caused by the sun angle above the horizon. [0163] Accordingly, the system described provides for the maintenance of optimal light levels in a space based upon optimal use of both daylight and artificial lighting provided by electric lamps. In addition, the system preferably automatically detects and reduces sun glare when sun glare presents a problem. [0164] Although the present invention has been described in relation to particular embodiments thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. Therefore, the present invention should be limited not by the specific disclosure herein, but only by the appended claims.

An illumination maintenance system for maintaining a desired illumination profile in a space throughout at least a portion of a day, the space being illuminable by both daylight and electric light, the system comprising a sensor for sensing an illumination level in at least a portion of the space; a plurality of dimmable electric lamps providing the electric light to supplement the daylight illumination of the space, the electric lamps arranged in one or more zones in the space, the zones defining predefined volumes of the space, each zone having at least one lamp; a control system controlling the dimming levels of the plurality of electric lamps, the at least one lamp of each zone being controlled to a dimming level to achieve a desired illumination level in the respective zone according to the desired illumination profile and compensate for the daylight illumination in the space throughout at least the portion of the day; wherein the dimming level of each lamp is selected by the control system from one of a plurality of lighting presets, each lighting preset comprising a combination of dimming levels of the lamps, and wherein the control system adjusts the dimming level of the electric lamps toward a preset that will result in an appropriate supplementing of the daylight illumination to achieve the desired illumination profile in the space.

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