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A robot has been known in which a vertical operation mechanism and a horizontal mechanism are combined in order to move a work such as a large-sized liquid crystal substrate up-down or horizontally, and the vertical operation mechanism takes charge of the up-down operation and the horizontal operation mechanism takes charge of the horizontal operation (For example, Patent Document 1, Patent Document 2, and Patent Document 3).
Patent Document 1: JP-A-2000-24966
Patent Document 2: JP-A-2002-326182
Patent Document 3: JP-A-11-123675 | {
"pile_set_name": "USPTO Backgrounds"
} |
The present invention relates to an aqueous primer or coating, particularly a primer for use in polymeric material-to-metal adhesive bonding and a coating for protecting metallic surfaces.
Primers are often used as an undercoat in combination with a covercoat adhesive in order to achieve superior bonding between two substrates made from different materials. One particular application for such primers is in bonding metal surfaces to elastomeric surfaces. Elastomer-to-metal bonding is subjected to severe environmental conditions in many industrial and automotive assemblies. For example, many engine mounting assemblies that employ elastomer-to-metal bonding contain fluids in order to assist in damping of vibration of the engine. These fluid-filled engine mounting devices are being exposed to increasingly high temperatures such that the elastomer-to-metal adhesive bonds within the mounts are being exposed to very high temperature fluid environments. Many elastomer-to-metal assemblies, particularly those utilized in automobile applications, are routinely exposed to materials that contain corrosive salts or other corrosive materials that may act to degrade the elastomer-to-metal adhesive bond.
In light of the increasing regulations regarding volatile organic compounds (VOC), the use of traditional solvent-borne adhesives is becoming more problematic. Consequently, there is significant ongoing work to develop water-borne replacements. For example, U.S. Pat. No. 4,167,500 describes an aqueous adhesive composition that includes a water-dispersible novolak resin, a methylene donor and water. Aqueous or water-borne primers are known and described in U.S. Pat. Nos. 5,200,455 and 5,162,156, but they have various shortcomings compared to solvent-borne primers. For example, it is desirable to improve the environmental resistance performance of aqueous elastomer-to-metal adhesion primers that include polyvinyl alcohol-stabilized phenolic resin dispersions (see U.S. Pat. No. 5,200,455) when used with certain important adhesive covercoats. Elastomer-to-metal primers that include phenolic resins derived from water soluble phenolic precursors are also known (see U.S. Pat. No. 5,162,156) but these suffer from drawbacks that prevent their use to form robust, environmentally resistant films. Before being thermoset, films formed from water soluble phenolic resins tend to re-solvate when exposed to water. The source of the water can be an aqueous covercoat applied to the film. Application of the aqueous covercoat essentially washes away the film formed from the water soluble phenolic resin. In addition, such films exhibit very limited resistance to corrosive fluids.
Another problem associated with the bonding of elastomer to metal relates to pre-heating or pre-baking of the dried adhesive prior to bonding. The metal substrate typically is coated with the adhesive, the adhesive is dried and then the adhesive-coated metal substrate is placed in a mold. Elastomer then is introduced into the mold and bonded to the metal substrate during vulcanization of the elastomer. The bonded part is removed from the mold and the next metal substrate is placed in the mold. When this subsequent metal substrate is placed in the mold it is subjected to the heat retained in the mold from the previous molding operation. The dried adhesive must be able to withstand this retained heat (referred to herein as xe2x80x9cpre-heatingxe2x80x9d) prior to bonding.
Consequently, there exists a continuing need for an aqueous primer that provides robust adhesive bonding in hot, corrosive environments, has an affinity for a broad range of covercoats, and forms a flexible film that is resistant to pre-heating conditions and exhibits superior shelf-life stability and resistance to resolvation. It would be especially advantageous if such a primer could also be used as a coating for protecting a metallic surface.
At present, there are two commonly-used metal coating methods electrodeposition and autodepositionxe2x80x94that are typically used subsequent to, or as a substitute for, phosphatizing of the metallic surface. Electrodeposition (frequently referred to as xe2x80x9cE-coatxe2x80x9d) involves immersing a metal surface in a composition then applying a voltage through the composition so that a coating will deposit on the metal surface. An autodeposition coating is commercially available from Henkel and its subsidiary Parker Amchem under the trademark AUTOPHORETIC(copyright).
According to the patents and commercial literature, immersion of a metallic surface in an autodeposition composition produces what is said to be a self-limiting protective coating on a metal substrate. Autodeposition compositions are known to generally include water, resin solids dispersed in the aqueous medium, and an activator. For example, the aqueous autodeposition solution in one commercial embodiment contains 3-5 percent solids of a latex (polyvinylidene chloride or acrylic) and carbon black, ferric fluoride and a low concentration of hydrofluoric acid to provide a solution pH of 2.5-3.0. According to the commercialized multi-stage process, a clean degreased steel panel is immersed in an autodeposition solution for one to two minutes, the resulting xe2x80x9cgreenxe2x80x9d film is rinsed in a reaction rinse solution and then dried at 100xc2x0 C. The reactive rinse solution can include a diphosphonic acid.
The dispersed resin solid typically is derived from ethylenically unsaturated monomers. Polyvinylidene chloride is the preferred resin. Polyethylene, polyacrylic, styrene-butadiene and epoxy resins are mentioned as possible resin particles that are dispersed or emulsified in water (see U.S. Pat. Nos. 4,414,350; 4,994,521; 5,427,863; 5,061,523; and 5,500,460). According to U.S. Pat. No. 5,486,414, AUTOPHORETIC(copyright) 800 Series compositions are based on polyvinylidene chloride and AUTOPHORETIC(copyright) 700 Series compositions are based on acrylic resins.
The activator is an ingredient or ingredients that convert the composition into one which will form a self-limiting resinous coating on a metallic surface. The activating system generally comprises an acidic oxidizing system, for example: hydrogen peroxide and HF; HNO3; a ferric-containing compound and HF; and other soluble metal-containing compounds, for example, silver fluoride, ferrous oxide, cupric sulfate, cobaltous nitrate, silver acetate, ferrous phosphate, chromium fluoride, cadmium flouride, stannous flouride, lead dioxide, and silver nitrate in an amount of 0.025 to 50 g/l and an acid, which can be used alone or in combination with hydrofluoric acid, and including, for example, sulfuric, hydrochloric, nitric and phosphoric acid, and organic acids, including, for example, acetic, chloroacetic and trichloroacetic acids.
In the case of treating zinciferous surfaces (e.g., galvanized steel), PCT International Patent Application Publication No. WO 97/09127 discloses treating the surface prior to autodeposition with a composition consisting of water, dissolved phosphonate (for example, diethylene triaminepenta(methylene phosphonic acid) or aminotri(methylene phosphonic acid)), aromatic sulfonate surfactant (for example, disulfonated derivative of dodecyl ether (DOWFAX 2A1 or 2A0)), and dissolved non-oxidizing acid (for example, hydrochloric acid).
Autodeposition coatings are recognized as being very distinct from coatings formed by immersing metallic surfaces in compositions simply comprising solid resin particles dispersed in water (in other words, conventional latices) and coatings formed from acidic aqueous coating compositions that contain dispersed solid resin particles and relatively high amounts of water soluble corrosion inhibitors such as hexavalent chromium compounds (see U.S. Pat. No. 4,242,379). In both instances, the thickness of the resulting coating is not determined by the amount of time in which the metallic surface is immersed in the composition.
According to the present invention there is provided a composition useful as a primer or a coating that includes (A) an aqueous dispersion of a phenolic resin that includes water and a reaction product of a phenolic resin precursor, a modifying agent and, optionally, a multi-hydroxy phenolic compound wherein the modifying agent includes at least one functional moiety that enables the modifying agent to react with the phenolic resin precursor and at least one ionic moiety, and (B) a flexibilizer. According to one embodiment the modifying agent is an aromatic compound. According to another embodiment the ionic moiety of the modifying agent is sulfate, sulfonate, sulfinate, sulfenate or oxysulfonate and the dispersed phenolic resin reaction product has a carbon/sulfur atom ratio of 20:1 to 200:1.
One preferred embodiment of the composition is particularly useful as a primer for bonding a metallic surface to a polymeric surface and includes a novolak version of the phenolic resin dispersion (A), the flexibilizer (B), and (C) an aldehyde, preferably formaldehyde, donor compound. According to another preferred embodiment the composition is a coating for a metallic surface that includes a resole version of the phenolic resin dispersion (A) and the flexibilizer (B).
When applied to a substrate surface, particularly a metal surface, and thermoset the composition forms a flexible film that protects the surface from high temperatures, corrosive conditions and chemical attack or degradation. In addition, when used as a primer in combination with an adhesive covercoat, the primer has improved adhesion to a broad range of covercoats and exhibits superior resistance to resolvation and chemically aggressive environments. The aqueous composition also has more than adequate shelf-life stability.
A unique advantage of the composition of the invention is that it is autodepositable when applied to an electrochemically active metallic surface. Autodeposition enables the composition to form a self-limiting, substantially uniform film.
There is also provided according to the invention a method for protectively coating a metallic substrate surface that includes (I) initially applying to the metallic substrate surface a metal treatment composition that contains (A) an aqueous dispersion of a phenolic novolak resin that includes water and a reaction product of a phenolic resin precursor, a modifying agent and a multi-hydroxy phenolic compound wherein the modifying agent includes at least one functional moiety that enables the modifying agent to react with the phenolic resin precursor and at least one ionic moiety, (B) an acid and, optionally, (C) a flexibilizer and then (II) applying to the treated metallic substrate surface the primer or coating composition described above.
Unless otherwise indicated, description of components in chemical nomenclature refers to the components at the time of addition to any combination specified in the description, but does not necessarily preclude chemical interactions among the components of a mixture once mixed.
Certain terms used in this document are defined below.
xe2x80x9cPrimerxe2x80x9d means a liquid composition applied to a surface as an undercoat beneath a subsequently-applied covercoat. The covercoat can be an adhesive and the primer/adhesive covercoat forms an adhesive system for bonding two substrates together.
xe2x80x9cCoatingxe2x80x9d means a liquid composition applied to a surface to form a protective and/or aesthetically pleasing coating on the surface.
xe2x80x9cPhenolic compoundxe2x80x9d means a compound that includes at least one hydroxy functional group attached to a carbon atom of an aromatic ring. Illustrative phenolic compounds include unsubstituted phenol per se, substituted phenols such as alkylated phenols and multi-hydroxy phenols, and hydroxy-substituted multi-ring aromatics. Illustrative alkylated phenols include methylphenol (also known as cresol), dimethylphenol (also known as xylenol), 2-ethylphenol, pentylphenol and tert-butyl phenol. xe2x80x9cMulti-hydroxy phenolic compoundxe2x80x9d means a compound that includes more than one hydroxy group on each aromatic ring. Illustrative multi-hydroxy phenols include 1,3-benzenediol (also known as resorcinol), 1,2-benzenediol (also known as pyrocatechol), 1,4-benzenediol (also known as hydroquinone), 1,2,3-benzenetriol (also known as pyrogallol), 1,3,5-benzenetriol and 4-tert-butyl-1,2-benzenediol (also known as tert-butyl catechol). Illustrative hydroxy-substituted multi-ring aromatics include 4,4xe2x80x2-isopropylidenebisphenol (also known as bisphenol A), 4,4xe2x80x2methylidenebisphenol (also known as bisphenol F) and naphthol.
xe2x80x9cAldehyde compoundxe2x80x9d means a compound having the generic formula RCHO. Illustrative aldehyde compounds include formaldehyde, acetaldehyde, propionaldehyde, n-butylaldehyde, n-valeraldehyde, caproaldehyde, heptaldehyde and other straight-chain aldehydes having up to 8 carbon atoms, as well as compounds that decompose to formaldehyde such as paraformaldehyde, trioxane, furfural, hexamethylenetriamine, acetals that liberate formaldehyde on heating, and benzaldehyde.
xe2x80x9cPhenolic resinxe2x80x9d generally means the reaction product of a phenolic compound with an aldehyde compound. The molar ratio of the aldehyde compound (for example, formaldehyde) reacted with the phenolic compound is referred to herein as the xe2x80x9cF/P ratioxe2x80x9d. The F/P ratio is calculated on a per hydroxy-substituted aromatic ring basis.
xe2x80x9cPhenolic resin precursorxe2x80x9d means an unmodified or conventional phenolic resin that is reacted with the aromatic modifying agent to produce the phenolic resin that is dispersed in an aqueous phase.
xe2x80x9cElectrochemically active metalsxe2x80x9d means iron and all metals and alloys more active than hydrogen in the electromotive series. Examples of electrochemically active metal surfaces include zinc, iron, aluminum and cold-rolled, polished, pickled, hot-rolled and galvanized steel.
xe2x80x9cFerrousxe2x80x9d means iron and alloys of iron.
The phenolic resin dispersion (A) of the inventive composition can be obtained by reacting or mixing a phenolic resin precursor and a modifying agentxe2x80x94theoretically via a condensation reaction between the phenolic resin precursor and the modifying agent.
One functional moiety provides the ionic pendant group that enables stable dispersion of the phenolic resin. Without the ionic pendant group, the phenolic resin would be unable to maintain a stable dispersion in water. Since the ionic pendant group provides for the stability of the dispersion there is no need, or at the most a minimal need, for surfactants. The presence of surfactants in an aqueous composition is a well-known hindrance to the composition""s performance.
The other important functional moiety in the modifying agent enables the modifying agent to react with the phenolic resin precursor. The modifying agent can contain more than one ionic pendant group and more than one reaction-enabling moiety.
Incorporation of aromatic sulfonate functional moieties into the phenolic resin structure via condensation is the preferred method of providing the ionic pendant groups. Accordingly, one class of ionic moieties are substituents on an aromatic ring that include a sulfur atom covalently or ionically bonded to a carbon atom of the aromatic ring. Examples of covalently bound sulfur-containing substituents are sulfonate (xe2x80x94S(O)2Oxe2x88x92M+), sulfinate (xe2x80x94S(O)Oxe2x88x92M+), sulfenate (xe2x80x94SOxe2x88x92M+) and oxysulfonate (xe2x80x94OS(O)2Oxe2x88x92M+), wherein M can be any monovalent ion such as Na, Li, K, or NR13 (wherein R1 is hydrogen or an alkyl). Another example of a covalently bound substituent is sulfate ion. Sulfonate is the preferred ionic group. The modifying agent should not include or introduce any multivalent ions into the phenolic resin dispersion since it is expected that the presence of multivalent ions would cause the phenolic resin to precipitate rather than remain dispersed.
The reaction-enabling functional moiety of the modifying agent can be any functional group that provides a site on the modifying agent for undergoing condensation with a phenolic resin. If the phenolic resin precursor is a resole, the modifying agent reacts with an alkylol or benzyl ether group of the resole. If the modifying agent is aromatic, the reaction-enabling functional moiety is a substituent on the aromatic ring that causes a site on the ring to be reactive to the alkylol or benzyl ether of the resole precursor. An example of such a substituent is a hydroxy or hydroxyalkyl, with hydroxy being preferred. The hydroxy- or hydroxyalkyl-substituted aromatic modifying agent is reactive at a site ortho and/or para to each hydroxy or hydroxyalkyl substituent. In other words, the aromatic modifying agent is bonded to, or incorporated into, the phenolic resin precursor at sites on the aromatic ring of the modifying agent that are ortho and/or para to a hydroxy or hydroxyalkyl substituent. At least two reaction-enabling functional moieties are preferred to enhance the reactivity of the aromatic modifying agent with the phenolic resin precursor.
Alternatively, the reaction-enabling functional moiety of the modifying agent can be a formyl group (xe2x80x94CHO), preferably attached to a carbon atom of an aromatic ring. In this instance, the phenolic resin precursor is a novolak rather than a resole. The novolak precursor is reacted via an acid catalyzed aldehyde condensation reaction with the formyl group-containing modifying agent so that the formyl group forms a divalent methylene linkage to an active site on an aromatic ring of the backbone structure of the novolak precursor. Consequently, the modifying agent structure (including the ionic moiety) is incorporated into the phenolic structure through the generated methylene linkage. Examples of such fdrmyl group-containing modifying agents include 2-formylbenzene sulfonate, 5-formylfuran sulfonate and (R)(SO3)CHxe2x80x94CH2xe2x80x94C(O)(H) compounds wherein R is C1-C4 alkyl groups.
Another alternative reaction-enabling functional moiety could be a diazo group (xe2x80x94N2+), preferably attached to a carbon atom of an aromatic ring. In this instance, the phenolic resin precursor is a novolak rather than a resole. The novolak precursor is reacted via a diazo coupling reaction with the diazo group-containing modifying agent so that the diazo group forms a divalent diazo linkage (xe2x80x94Nxe2x95x90) to an active site on an aromatic ring of the backbone structure of the novolak precursor. Consequently, the modifying agent structure (including the ionic moiety) is incorporated into the phenolic structure through the diazo linkage. An example of such a diazo modifying agent is 1-diazo-2-naphthol-4-sulfonic acid.
The modifying agent also can optionally include a functional moiety that is capable of chelating with a metal ion that is present on a substrate surface on which the phenolic resin dispersion is applied. The chelating group remains as a residual group after the condensation of the phenolic resin precursor and the aromatic modifying agent. Typically, the chelating group is a substituent on the aromatic ring that is capable of forming a 5- or 6-membered chelation structure with a metal ion. Examples of such substituents include hydroxy and hydroxyalkyl, with hydroxy being preferred. At least two such functional groups must be present on the modifying agent molecule to provide the chelating. In the case of an aromatic modifying agent, the chelating groups should be located in an ortho position relative to each other. A significant advantage of the invention is that hydroxy or hydroxyalkyl substituents on the aromatic modifying agent can serve two rolesxe2x80x94condensation enablement and subsequent metal chelating.
An aromatic modifying agent is particularly advantageous. Preferably, the ionic group and the reaction-enabling moiety are not substituents on the same aromatic ring. The ionic group, particularly sulfonate, appears to have a strong deactivating effect on condensation reactions of the ring to which it is attached. Consequently, an ionic group attached to the same ring as the reaction-enabling moiety would not allow the modifying agent to readily react with the phenolic resin precursor. However, it should be recognized that this consideration for the location of the ionic and reaction-enabling moieties is not applicable to the formyl group-containing modifying agent and diazo modifying agent.
A preferred structure for the aromatic modifying agent is represented by formulae Ia or Ib below:
wherein X is the ionic group; Y is the reaction-enabling substituent; Z is the chelating substituent; L1 is a divalent linking group such as an alkylene radical (for example, methylene) or a diazo (xe2x80x94Nxe2x95x90Nxe2x80x94); a is 1; b is 1 to 4; m is 0 or 1; and c and d are each independently 0 to 3, provided there are not more than 4 substituents on each aromatic ring. If a chelating group Z is present it is positioned ortho to another chelating group Z or to Y. It should be recognized that the reaction-enabling substituent Y may also act as a chelating substituent. In this instance, the aromatic modifying agent may not include an independent chelating substituent Z. An aromatic modifying agent according to formulae Ia or Ib could also include other substituents provided they do not adversely interfere with the ionic group or the condensation reaction.
Illustrative aromatic modifying agents include salts of 6,7-dihydroxy-2-napthalenesulfonate; 6,7-dihydroxy-1-naphthalenesulfonate; 6,7-dihydroxy-4-napthalenesulfonate; Acid Red 88; Acid Alizarin Violet N; Erichrome Black T; Erichrome Blue Black B; Brilliant Yellow; Crocein Orange G; Biebrich Yellow; and Palatine Chrome Black 6BN. 6,7-dihydroxy-2-naphthalenesulfonate, sodium salt is the preferred aromatic modifying agent.
It should be recognized that the preferred sulfonate modification contemplated herein involves an indirect sulfonation mechanism. In other words, the aromatic modifying agent includes a sulfonate group and is reacted with another aromatic compound (the phenolic resin precursor) to obtain the chain extended, sulfonate-modified phenolic resin product. This indirect sulfonation is distinctly different than direct sulfonation of the phenolic resin precursor.
Any phenolic resin could be employed as the phenolic resin precursor, but it has been found that resoles are especially suitable. The resole precursor should have a sufficient amount of active alkylol or benzyl ether groups that can initially condense with the modifying agent and then undergo further subsequent condensation. Of course, the phenolic resin precursor has a lower molecular weight than the final dispersed resin since the precursor undergoes condensation to make the final dispersed resin. Resoles are prepared by reacting a phenolic compound with an excess of an aldehyde in the presence of a base catalyst. Resole resins are usually supplied and used as reaction product mixtures of monomeric phenolic compounds and higher molecular weight condensation products having alkylol (xe2x80x94ArCH2xe2x80x94OH) or benzyl ether termination (xe2x80x94ArCH2xe2x80x94Oxe2x80x94CH2Ar), wherein Ar is an aryl group. These resole mixtures or prepolymers (also known as stage A resin) can be transformed into three-dimensional, crosslinked, insoluble and infusible polymers by the application of heat.
The reactants, conditions and catalysts for preparing resoles suitable for the resole precursor of the present invention are well-known. The phenolic compound can be any of those previously listed or other similar compounds, although multi-hydroxy phenolic compounds are undesirable. Particularly preferred phenolic compounds for making the resole precursor include phenol per se and alkylated phenol. The aldehyde also can be any of those previously listed or other similar compounds, with formaldehyde being preferred. Low molecular weight, water soluble or partially water soluble resoles are preferred as the precursor because such resoles maximize the ability to condense with the modifying agent. The F/P ratio of the resole precursor should be at least 0.90. Illustrative commercially available resoles that are suitable for use as a precursor include a partially water soluble resole available from Georgia Pacific under the trade designation BRL 2741 and a partially water soluble resoles available from Schenectady International under the trade designations HRJ11722 and SG3100.
As described above, the dispersed phenolic resin reaction product according to the invention can be hydrophilic or hydrophobic, but hydrophilic is preferred. In addition, dispersed resoles or novolaks can be obtained depending upon the selection and amount of reactants.
Preferably, the dispersed resole is produced by reacting or mixing 1 mol of modifying agent(s) with 1 to 20 mol of phenolic resin precursor(s). A dispersed resole typically can be obtained by reacting or mixing a resole precursor or a mixture of resole precursors with the modifying agent or a mixture of agents without any other reactants, additives or catalysts. However, other reactants, additives or catalysts can be used as desired. Multi-hydroxy phenolic compound(s) can optionally be included in relatively small amounts in the reactant mixture for the resole.
Hydrophilic resoles typically have a F/P ratio of at least 1.0. According to the invention, hydrophilic resoles having a F/P ratio much greater than 1.0 can be successfully dispersed. For example, it is possible to make an aqueous dispersion of hydrophilic resoles having a F/P ratio of at least 2 and approaching 3, which is the theoretical F/P ratio limit.
Preferably, the dispersed novolak is produced by reacting 1 mol of modifying agent(s) with 2-20 mol of phenolic resin precursor(s) and, preferably, 2-20 mol of multi-hydroxy phenolic compound(s). An aldehyde compound, preferably formaldehyde, is also required to make the novolak. The aldehyde compound can optionally be added as a separate ingredient in the initial reaction mixture or the aldehyde compound can be generated in situ from the resole precursor. The resole precursor(s), multi-hydroxy phenolic compound(s) and modifying agent(s) co-condense to form the dispersed novolak. The reaction typically is acid catalyzed with an acid such as phosphoric acid. The F/P ratio of aldehyde compound(s) to combined amount of resole precursor(s) and multi-hydroxy phenolic compound(s) in the initial reaction mixture preferably is less than 0.9. Preferably, synthesis of the dispersed novolak is a two stage reaction. In the first stage, the resole precursor(s) is reacted with the modifying agent(s) and, optionally, a small amount of multi-hydroxy phenolic compound(s). Once this first stage reaction has reached the desired point (i.e. the resin can be readily formed into a translucent dispersion), the acid catalyst and a greater amount of multi-hydroxy phenolic compound(s) is added to the reaction mixture. Pyrocatechol (also simply known as catechol) is a preferred multi-hydroxy phenolic compound for reacting in the first stage and resorcinol is a preferred multi-hydroxy phenolic compound for reacting in the second stage.
Hydrophilic novolaks typically have a hydroxy equivalents of between 1 and 3 per aromatic ring. Preferably, dispersed hydrophilic novolaks according to the invention have a hydroxy equivalents of 1.1 to 2.5, more preferably 1.1 to 2.0. The hydroxy equivalents is calculated based on the amount of multi-hydroxy phenolic compounds used to make the novolak.
According to a preferred embodiment, the dispersed phenolic resin reaction product contains a mixture of oligomers having structures believed to be represented by the following formulae IIa or IIb:
wherein X, Y, Z and L1 and subscripts a, b, c, d and m are the same as in formulae Ia and Ib, e is 1 to 6, L2 is a divalent linking group and Ph is the phenolic resin backbone structure, provided the xe2x80x94(L2xe2x80x94Ph) group(s) is(are) ortho or para to a Y group. L2 depends upon the particular phenolic resin, but typically is a divalent alkylene radical such as methylene (xe2x80x94CH2xe2x80x94) or oxydimethylene (xe2x80x94CH2xe2x80x94Oxe2x80x94CH2xe2x80x94). Preferably, e is 2 and the xe2x80x94(L2xe2x80x94Ph) groups are in para position to each other.
According to a particularly preferred embodiment wherein the phenolic resin is a resole and the modifying agent is a naphthalene having a ionic pendant group X and two reaction-enabling substituents Y, the dispersed phenolic resin reaction product contains a mixture of oligomers having structures believed to be represented by the following formula III:
wherein X and Y are the same as in formulae Ia and Ib, a is 0 or 1; n is 0 to 5; R2 is independently xe2x80x94C(R5)2xe2x80x94 or xe2x80x94C(R5)2xe2x80x94Oxe2x80x94C(R5)2xe2x80x94, wherein R5 is independently hydrogen, alkylol, hydroxyl, alkyl, aryl or aryl ether; and R3 is independently alkylol, alkyl, aryl, alkylaryl or aryl ether. Preferably, R2 is methylene or oxydimethylene and R3 is methylol. If 6,7-dihydroxy-2-naphthalenesulfonate, sodium salt is the modifying agent, X will be SO3xe2x88x92Na+ and each Y will be OH. It should be recognized that in this case the hydroxy groups for Y will also act as chelating groups with a metal ion.
According to another preferred embodiment wherein the phenolic resin is a novolak and the modifying agent is a naphthalene having a ionic pendant group X and two reaction-enabling substituents Y, the dispersed phenolic resin reaction product contains a mixture of oligomers having structures believed to be represented by the following formula IV:
wherein X and Y are the same as in formulae Ia and Ib, a is 0 or 1, n is 0 to 5 and R4 is independently hydroxyl, alkyl, aryl, alkylaryl or aryl ether. Preferably, R4 is tert-butyl. If 6,7-dihydroxy-2-naphthalenesulfonate, sodium salt is the modifying agent, X will be SO3xe2x88x92Na+ and each Y will be OH. In this case the hydroxy groups for Y will also act as chelating groups with a metal ion.
It should be recognized that the dispersed phenolic resin reaction product may contain oligomers.or compounds having structures that vary from the idealized structures shown in formulae III and IV.
If the modifying agent includes a sulfur-containing ionic group, the resulting modified phenolic resin should have a carbon/sulfur atom ratio of 20:1 to 200:1, preferably 20:1 to 100:1. If the sulfur content is greater than the 20:1 carbon/sulfur atom ratio, the modified phenolic resin begins to become water soluble, is more stable with respect to multivalent ions and is difficult to thermoset. These characteristics are adverse to the preferred use of the phenolic resin dispersion of the invention. If the sulfur content is below the 200:1 carbon/sulfur atom ratio, then the resin dispersion cannot maintain its stability. Viewed another way, the dispersed phenolic resins have 0.01 to 0.10, preferably 0.03 to 0.06, equivalents of sulfonate functionality/100 g resin. The aqueous dispersion of the phenolic resin preferably has a solids content of 1 to 50, preferably 15 to 30.
The modifying agent and the phenolic resin precursor can be reacted or mixed under conditions effective to promote condensation of the modifying agent with the phenolic resin precursor. The reaction is carried out in water under standard phenolic resin condensation techniques and conditions. The reactant mixture (including water) generally is heated from 50 to 100xc2x0 C. under ambient pressure, although the specific temperature may differ considerably depending upon the specific reactants and the desired reaction product. The resulting product is a concentrate that is self-dispersible upon the addition of water and agitation to reach a desired solids content. The final dispersion can be filtered to remove any gelled agglomerations.
The intermediate modified resoles or novolaks that are initially produced in the synthesis are not necessarily water dispersible, but as the chain extension is advanced the resulting chain extended modified resoles or novolaks become progressively more water dispersible by simple mechanical agitation. The chain extension for the dispersed resole is determined by measuring the viscosity of the reaction mixture. Once the resole reaction mixture has a reached the desired viscosity, which varies depending upon the reactant composition, the reaction is stopped by removing the heat. The chain extension for the dispersed novolak is determined by pre-selecting the F/P ratio of the total reaction mixture (in other words, the amount of aldehyde compound(s) relative to the amount of phenolic(s) in both the first and second stages). The reaction for the novolak is allowed to proceed until substantially all the total amount of the reactants have reacted. In other words, there is essentially no unreacted reactant remaining. Preferably, the molecular weight (i.e., chain extension) of both the resole and novolak should be advanced to just below the gel point.
The phenolic resin dispersion (A) can be present in the primer or coating composition in any amount. Preferably, it is present in an amount of 1 to 30, more preferably, 8 to 15, based on the total weight of the non-volatile components of the composition.
The flexibilizer (B) is any material that contributes flexibility and/or toughness to the film formed from the composition. The toughness provided by the flexibilizer provides fracture resistance to the film. The flexibilizer should be non-glassy at ambient temperature and be an aqueous emulsion latex or aqueous dispersion that is compatible with the phenolic resin dispersion (A). The flexibilizer preferably is formulated into the composition in the form of an aqueous emulsion latex or aqueous dispersion
Suitable flexibilizers include aqueous latices, emulsions or dispersions of (poly)butadiene, neoprene, styrene-butadiene rubber, acrylonitrile-butadiene rubber (also known as nitrile rubber), halogenated polyolefin, acrylic polymer, urethane polymer, ethylene-propylene copolymer rubber, ethylene-propylene-diene terpolymer rubber, styrene-acrylic copolymer, polyamide, poly(vinyl acetate) and the like. Halogenated polyolefins, nitrile rubbers and styrene-acrylic copolymers are preferred.
A suitable styrene-acrylic polymer latex is commercially available from Goodyear Tire and Rubber under the trade designation PLIOTEC and described, for example, in U.S. Pat. Nos. 4,968,741; 5,122,566 and 5,616,635. According to U.S. Pat. No. 5,616,635, such a copolymer latex is made from 45-85 weight percent vinyl aromatic monomers, 15-50 weight percent of at least one alkyl acrylate monomer and 1-6 weight percent unsaturated carbonyl compound. Styrene is the preferred vinyl aromatic monomer, butyl acrylate is the preferred acrylate monomer and acrylic acid and methacrylic acid are the preferred unsaturated carbonyl compound. The mixture for making the latex also includes at least one phosphate ester surfactant, at least one water-insoluble nonionic surface active agent and at least one free radical initiator.
If nitrile rubber is the flexibilizer, it is preferably mixed into the composition as an emulsion latex. It is known in the art that nitrile rubber emulsion latices are generally made from at least one monomer of acrylonitrile or an alkyl derivative thereof and at least one monomer of a conjugated diene, preferably butadiene. According to U.S. Pat. No. 4,920,176 the acrylonitrile or alkyl derivative monomer should be present in an amount of 0 or 1 to 50 percent by weight based on the total weight of the monomers. The conjugated diene monomer should be present in an amount of 50 percent to 99 percent by weight based on the total weight of the monomers. The nitrile rubbers can also optionally include various co-monomers such as acrylic acid or various esters thereof, dicarboxylic acids or combinations thereof. The polymerization of the monomers typically is initiated via free radical catalysts. Anionic surfactants typically are also added. A suitable nitrile rubber latex is available from B.F. Goodrich under the trade designation HYCAR.
Representative halogenated polyolefins include chlorinated natural rubber, chlorine- and bromine-containing synthetic rubbers including polychloroprene, chlorinated polychloroprene, chlorinated polybutadiene, hexachloropentadiene, butadiene/halogenated cyclic conjugated diene adducts, chlorinated butadiene styrene copolymers, chlorinated ethylene propylene copolymers and ethylene/propylene/non-conjugated diene terpolymers, chlorinated polyethylene, chlorosulfonated polyethylene, poly(2,3-dichloro-1,3-butadiene), brominated poly(2,3-dichloro-1,3-butadiene), copolymers of xcex1-haloacrylonitriles and 2,3-dichloro-1,3-butadiene, chlorinated poly(vinyl chloride) and the like including mixtures of such halogen-containing elastomers.
Latices of the halogenated polyolefin can be prepared according to methods known in the art such as by dissolving the halogenated polyolefin in a solvent and adding a surfactant to the resulting solution. Water can then be added to the solution under high shear to emulsify the polymer. The solvent is then stripped to obtain a latex. The latex can also be prepared by emulsion polymerization of the halogenated ethylenically unsaturated monomers.
Butadiene latices are particularly preferred as the flexibilizer (B). Methods for making butadiene latices are well-known and are described, for example, in U.S. Pat. Nos. 4,054,547 and 3,920,600, both incorporated herein by reference. In addition, U.S. Pat. Nos. 5,200,459; 5,300,555; and 5,496,884 disclose emulsion polymerization of butadiene monomers in the presence of polyvinyl alcohol and a co-solvent such as an organic alcohol or a glycol.
The butadiene monomers useful for preparing the butadiene polymer latex can essentially be any monomer containing conjugated unsaturation. Typical monomers include 2,3-dichloro-1,3-butadiene; 1,3-butadiene; 2,3-dibromo-1,3-butadiene isoprene; isoprene; 2,3-dimethylbutadiene; chloroprene; bromoprene; 2,3-dibromo-1,3-butadiene; 1,1,2-trichlorobutadiene; cyanoprene; hexachlorobutadiene; and combinations thereof. It is particularly preferred to use 2,3-dichloro-1,3-butadiene since a polymer that contains as its major portion 2,3-dichloro-1,3-butadiene monomer units has been found to be particularly useful in adhesive applications due to the excellent bonding ability and barrier properties of the 2,3-dichloro-1,3-butadiene-based polymers. As described above, an especially preferred embodiment of the present invention is one wherein the butadiene polymer includes at least 60 weight percent, preferably at least 70 weight percent, 2,3-dichloro-1,3-butadiene monomer units.
The butadiene monomer can be copolymerized with other monomers. Such copolymerizable monomers include xcex1-haloacrylonitriles such as xcex1-bromoacrylonitrile and xcex1-chloroacrylonitrile; xcex1,xcex2-unsaturated carboxylic acids such as acrylic, methacrylic, 2-ethylacrylic, 2-propylacrylic, 2-butylacrylic and itaconic acids; alkyl-2-haloacrylates such as ethyl-2-chloroacrylate and ethyl-2-bromoacrylate; xcex1-bromovinylketone; vinylidene chloride; vinyl toluenes; vinylnaphthalenes; vinyl ethers, esters and ketones such as methyl vinyl ether, vinyl acetate and methyl vinyl ketone; esters amides, and nitriles of acrylic and methacrylic acids such as ethyl acrylate, methyl methacrylate, glycidyl acrylate, methacrylamide and acrylonitrile; and combinations of such monomers. The copolymerizable monomers, if utilized, are preferably xcex1-haloacrylonitrile and/or xcex1,xcex2-unsaturated carboxylic acids. The copolymerizable monomers may be utilized in an amount of 0.1 to 30 weight percent, based on the weight of the total monomers utilized to form the butadiene polymer.
In carrying out the emulsion polymerization to produce the latex other optional ingredients may be employed during the polymerization process. For example, conventional anionic and/or nonionic surfactants may be utilized in order to aid in the formation of the latex. Typical anionic surfactants include carboxylates such as fatty acid soaps from lauric, stearic, and oleic acid; acyl derivatives of sarcosine such as methyl glycine; sulfates such as sodium lauryl sulfate; sulfated natural oils and esters such as Turkey Red Oil; alkyl aryl polyether sulfates; alkali alkyl sulfates; ethoxylated aryl sulfonic acid salts; alkyl aryl polyether sulfonates; isopropyl naphthalene sulfonates; sulfosuccinates; phosphate esters such as short chain fatty alcohol partial esters of complex phosphates; and orthophosphate esters of polyethoxylated fatty alcohols. Typical nonionic surfactants include ethoxylated (ethylene oxide) derivatives such as ethoxylated alkyl aryl derivatives; mono- and polyhydric alcohols; ethylene oxide/propylene oxide block copolymers; esters such as glyceryl monostearate; products of the dehydration of sorbitol such as sorbitan monostearate and polyethylene oxide sorbitan monolaurate; amines; lauric acid; and isopropenyl halide. A conventional surfactant, if utilized, is employed in an amount of 0.01 to 5 parts, preferably 0.1 to 2 parts, per 100 parts by weight of total monomers utilized to form the butadiene polymer.
In the case of dichlorobutadiene homopolymers, anionic surfactants are particularly useful. Such anionic surfactants include alkyl sulfonates and alkyl aryl sulfonates (commercially available from Stepan under the trade designation POLYSTEP) and sulfonic acids or salts of alkylated diphenyl oxide (for example, didodecyl diphenyleneoxide disulfonate or dihexyl diphenyloxide disulfonate commercially available from Dow Chemical Co. under the trade designation DOWFAX).
Chain transfer agents may also be employed during emulsion polymerization in order to control the molecular weight of the butadiene polymer and to modify the physical properties of the resultant polymer as is known in the art. Any of the conventional organic sulfur-containing chain transfer agents may be utilized such as alkyl mercaptans and dialkyl xanthogen disulfides.
The emulsion polymerization is typically triggered by a free radical initiator. Illustrative free radical initiators include conventional redox systems, peroxide systems, azo derivatives and hydroperoxide systems. The use of a redox system is preferred and examples of such systems include ammonium persulfate/sodium metabisulfite, ferric sulfate/ascorbic acid/hydroperoxide and tributylborane/hydroperoxide, with ammonium persulfate/sodium metabisulfite being most preferred.
The emulsion polymerization is typically carried out at a temperature of 10xc2x0-90xc2x0 C., preferably 40xc2x0-60xc2x0 C. Monomer conversion usually ranges from 70-100, preferably 80-100, percent. The latices preferably have a solids content of 10 to 70, more preferably 30 to 60, percent; a viscosity between 50 and 10,000 centipoise at 25xc2x0 C.; and a particle size between 60 and 300 nanometers.
Especially preferred as the butadiene latex is a butadiene polymer that has been emulsion polymerized in the presence of a styrene sulfonic acid, styrene sulfonate, poly(styrene sulfonic acid), or poly(styrene sulfonate) stabilizer to form the latex. Poly(styrene sulfonate) is the preferred stabilizer. This stabilization system is particularly effective for a butadiene polymer that is derived from at least 60 weight percent dichlorobutadiene monomer, based on the amount of total monomers used to form the butadiene polymer. The butadiene polymer latex can be made by known emulsion polymerization techniques that involve polymerizing the butadiene monomer (and copolymerizable monomer, if present) in the presence of water and the styrene sulfonic acid, styrene sulfonate, poly(styrene sulfonic acid), or poly(styrene sulfonate) stabilizer. The sulfonates can be salts of any cationic groups such as sodium, potassium or quaternary ammonium. Sodium styrene sulfonate is a preferred styrene sulfonate compound. Poly(styrene sulfonate) polymers include poly(styrene sulfonate) homopolymer and poly(styrene sulfonate) copolymers such as those with maleic anhydride. Sodium salts of poly(styrene sulfonate) are particularly preferred and are commercially available from National Starch under the trade designation VERSA TL. The poly(styrene sulfonate) can have a weight average molecular weight from 5xc3x97104 to 1.5xc3x97106, with 1.5xc3x97105 to 2.5xc3x97105 being preferred. In the case of a poly(styrene sulfonate) or poly(styrene sulfonic acid) it is important to recognize that the emulsion polymerization takes place in the presence of the pre-formed polymer. In other words, the butadiene monomer is contacted with the pre-formed poly(styrene sulfonate) or poly(styrene sulfonic acid). The stabilizer preferably is present in an amount of 0.1 to 10 parts, preferably 1 to 5 parts, per 100 parts by weight of total monomers utilized to form the butadiene polymer.
The flexibilizer (B) preferably is present in the composition in an amount of 5 parts by weight to 300 parts by weight, based on 100 parts by weight phenolic resin dispersion. More preferably, the flexibilizer is present in an amount of 25 parts by weight to 100 parts by weight, based on 100 parts by weight phenolic resin dispersion.
The composition also can optionally include ingredients known to be useful in adhesive compositions. A particular useful optional component is a metal oxide such as zinc oxide, magnesium oxide, lead oxide, iron oxide, cadmium oxide, zirconium oxide and calcium oxide, with zinc oxide and magnesium oxide being preferred. Lead oxide is not preferred due to environmental concerns. The metal oxides are well-known articles of commerce. The metal oxide is formulated into the composition in finely divided form or as a dispersion in an aqueous carrier. Another useful ingredient is mica.
Other possible conventional additives include such as inert filler material, pigments, plasticizers, dispersing agents, wetting agents, reinforcing agents and the like in amounts conventionally utilized. Examples of such conventional additives include carbon black, silica, sodium aluminosilicate, titanium dioxide and organic pigments and dyestuffs. The composition of the invention preferably does not include any acid.
As mentioned above, one preferred embodiment of the composition is a primer for bonding a metallic surface to a polymeric surface that includes a novolak version of the phenolic resin dispersion (A), the flexibilizer (B), and (C) an aldehyde, preferably formaldehyde, donor compound that is capable of crosslinking the novolak resin.
The viscosity of the adhesive primer composition is not critical provided it is sufficient to withstand dripping and/or sagging. Typically, the adhesive primer may have a viscosity of 30 to 150 centipoise at 25xc2x0 C.
The aldehyde donor can be essentially be any type of aldehyde known to react with hydroxy aromatic compounds to form cured or crosslinked novolak phenolic resins. Typical compounds useful as a aldehyde (e.g., formaldehyde) source in the present invention include formaldehyde and aqueous solutions of formaldehyde, such as formalin; acetaldehyde; propionaldehyde; isobutyraldehyde; 2-ethylhexaldehyde; 2-methylpentaldehyde; 2-ethylhexaldehyde; benzaldehyde; as well as compounds which decompose to formaldehyde, such as paraformaldehyde, trioxane, furfural, hexamethylenetetramine, anhydromaldehydeaniline, ethylene diamine formaldehyde; acetals which liberate formaldehyde on heating; methylol derivatives of urea and formaldehyde; methylol phenolic compounds; and the like. The formaldehyde source is utilized in an amount ranging from about 5 parts by weight to 100 parts by weight, preferably from about 10 parts by weight to 70 parts by weight, based on 100 parts by weight phenolic resin dispersion.
Additionally, , high molecular weight aldehyde homopolymers and copolymers can be employed as a latent formaldehyde source in the practice of the present invention. A latent formaldehyde source herein refers to a formnaldehyde source which will release formaldehyde only in the presence of heat such as the heat applied during the curing of an adhesive system. Typical high molecular weight aldehyde homopolymers and copolymers include (1) acetal homopolymers, (2) acetal copolymers, (3) gamma-polyoxy-methylene ethers having the characteristic structure:
R10Oxe2x80x94(CH2O)nxe2x80x94R11
and (4) polyoxymethylene glycols having the characteristic structure:
HOxe2x80x94(R12O)xxe2x80x94(CH2O)nxe2x80x94(R13O)xxe2x80x94H
wherein R10 and R11 can be the same or different and each is an alkyl group having from about 1 to 8, preferably 1 to 4, carbon atoms, R12 and R13 can be the same or different and each is an alkylene group having from 2 to 12, preferably 2 to 8, carbon atoms; n is greater than 100, and is preferably in the range from about 200 to about 2000; and x is in the range from about 0 to 8, preferably 1 to 4, with at least one x being equal to at least 1. The high molecular weight aldehyde homopolymers and copolymers are further characterized by a melting point of at least 75xc2x0 C., i.e. they are substantially inert with respect to the phenolic system until heat activated; and by being substantially completely insoluble in water at a temperature below the melting point. The acetal homopolymers and acetal copolymers are well-known articles of commerce. The polyoxymethylene materials are also well known and can be readily synthesized by the reaction of monoalcohols having from 1 to 8 carbon atoms or dihydroxy glycols and ether glycols with polyoxymethylene glycols in the presence of an acidic catalyst. A representative method of preparing these crosslinking agents is described in U.S. Pat. No. 2,512,950, which is incorporated herein by reference. Gamma-polyoxymethylene ethers are generally preferred sources of latent formaldehyde and a particularly preferred latent formaldehyde source for use in the practice of the invention is 2-polyoxymethylene dimethyl ether.
As mentioned above, another preferred embodiment of the composition is a coating for a metallic surface that includes a resole version of the phenolic resin dispersion (A) and the flexibilizer (B). This coating can also be used as primer for polymeric-to-metal adhesion. Accordingly, the coating can be applied to substantially all of a metallic surface and then a portion of that coating-covered surface can be topcoated with a covercoat and then bonded to a polymeric surface. This single coating/primer composition provides significant corrosion protection under the bonded portion and in the exposed portion. According to conventional practices prior to this invention, the entire metal surface of a substrate is first coated with a protective coating and then only that portion intended for bonding must be coated with a primer having a composition different than that of the protective coating. Alternatively, the primer and adhesive are applied to the bonding area and then the resulting bonded assembly is post-painted with a protective coating. The invention provides a distinct processing advantage since the same composition can be used for both protective coating and priming for bonding on a metal surface and it eliminates the need for post-painting. Consequently, it is easier to ensure that the whole metal substrate or part has adequate corrosion protection.
The viscosity of the coating composition is not critical provided it is sufficient to withstand dripping and/or sagging. Typically, the coating composition can have a viscosity of less than 25 centipoise at 25xc2x0 C. Substantial elimination of dripping and/or sagging at such low viscosities is another benefit of the present invention.
A preferred optional component in the resole coating composition is a polyvinyl alcohol-stabilized aqueous resole dispersion. This dispersion can be prepared by a process that includes mixing the pre-formed, solid, substantially water-insoluble, resole resin; an organic coupling agent; and polyvinyl alcohol, at a temperature and for a period of time sufficient to form a dispersion of the resole in water. Such polyvinyl alcohol-stabilized resoles are described in more detail in U.S. Pat. No. 4,124,554, incorporated herein by reference, and are available commercially from Georgia Pacific under the trade designation BKUA-2370 and BKUA-2392. According to U.S. Pat. No. 4,124,554, the water-insoluble resole is produced by reacting formaldehyde with bisphenol-A in a mol ratio of 2 to 3.75 moles of formaldehyde per mole of bisphenol-A in the presence of a catalytic amount of an alkali metal or barium oxide or hydroxide condensation catalyst wherein the reaction is carried out at elevated temperatures. The condensation product is the neutralized to a pH of 3 to 8. Alcohols, glycol ethers, ethers, esters and ketones are the most useful coupling solvents. Specific examples of useful coupling solvents include ethanol, n-propanol, isopropyl alcohol, ethylene glycol monobutyl ether, ethylene glycol monoisobutyl ether, ethylene glycol monomethyl ether acetate, diethylene glycol monobutyl ether, diethylene glycol monoethyl ether acetate, propylene glycol monopropyl ether, methoxy acetone, and the like. The polyvinyl alcohol is typically prepared by hydrolysis of polyvinyl acetate. The most useful polyvinyl alcohol polymers are hydrolyzed to an extent of 85 to 91 percent and have molecular weights such that a 4 percent solids solution of the polyvinyl alcohol in water has a viscosity of 4 to 25 centipoises at 25xc2x0 C. The polyvinyl alcohol-stabilized resole dispersion, if present, typically is used in an amount of 10 parts by weight to 800 parts by weight, preferably 100 parts by weight to 800 parts by weight, based on 100 parts by weight of the phenolic resin dispersion (A).
Water, preferably deionized water, is utilized in combination with the phenolic resin dispersion (A), flexibilizer (B) and any optional components of the invention in order to provide a composition having a final solids content of 5 to 50, preferably 15 to 30, weight percent. Since the coating or primer composition is waterborne it is substantially free of volatile organic compounds.
The compositions may be prepared by any method known in the art, but are preferably prepared by combining and milling or shaking the ingredients and water in ball-mill, sand-mill, ceramic bead-mill, steel-bead mill, high speed media-mill or the like. It is preferred to add each component to the mixture in a liquid form such as an aqueous dispersion.
The composition may be applied to a substrate surface by any conventional method such as spraying, dipping, brushing, wiping, roll-coating (including reverse roll-coating) or the like, after which the composition typically is permitted to dry. Although conventional application methods can be used, the composition can be applied via autodeposition. The phenolic resin dispersion (A) of composition of the invention enables autodeposition of the composition in the presence of multivalent ions. The general principles and advantages of autodeposition is explained in a multitude of patents assigned to Parker Amchem and/or Henkel (see, for example, U.S. Pat. Nos. 4,414,350; 4,994,521; 5,427,863; 5,061,523 and 5,500,460). Autodepositable compositions usually are applied by dipping the metallic substrate or part into a bath of the composition. The metal substrate can reside in the primer or coating composition bath for an amount of time sufficient to deposit a uniform film of desired thickness. Typically, the bath residence time is from about 5 to about 120 seconds, preferably about 10 to about 30 seconds, and occurs at room temperature. The composition typically is applied to form a dry film thickness of 10 to 30 xcexcm.
According to the present invention when the composition is applied to an electrochemically active metal surface that has been activated so that there are multivalent ions present on the surface the multivalent ions appear to cause the composition to deposit on the metal surface a self-limiting, substantially uniform, gelatinous, wet film. The coating that is formed when the composition is in contact with the metal surface is known as the xe2x80x9cuncuredxe2x80x9d state. The subsequent drying of the coating converts the coating to a xe2x80x9ccuredxe2x80x9d stage. The formation of the coating is xe2x80x9cself-limitingxe2x80x9d in that the coating increases in thickness and areal density (mass per unit area) the longer the time the metal surface is immersed in the autodepositable composition.
The autodeposition characteristic of the invention is important to provide corrosion and environmental resistance. It allows for the formation of an exceptionally uniform and thin protective barrier. Excellent corrosion and environmental resistance is possible only if the entire surface of a metal part is protected with a barrier coating. This requirement is usually difficult to achieve on substrate surfaces that have a very complex topology. With the superior autodeposition of this invention, wetting and thus protection of such complex surfaces is achieved.
Another important advantage of the primer or coating composition is that a bath of the composition does not appear to change in composition as cumulative metal surfaces are dipped in the bath over a period of time. It is believed that since the very hydrophilic phenolic resin dispersion immobolizes or coagulates on the surface as a swollen wet gel rather than as a precipitate, the composition of the bath is the same as the deposited wet gel and the bath is not depleted.
Activation of the metallic surface to prepare it for receiving the autodepositable composition can be achieved by pretreating the surface with an activating composition that generates freely-available multivalent ions on the surface. The activating composition can be an aqueous solution of multivalent ions such as calcium, magnesium, iron and manganese.
The activating composition can also be an autodepositable, aqueous metal treatment composition that includes (Axe2x80x2) an aqueous dispersion of a phenolic novolak resin that includes water and a reaction product of a phenolic resin precursor, a modifying agent and a multi-hydroxy phenolic compound wherein the modifying agent includes at least one functional moiety that enables the modifying agent to react with the phenolic resin precursor and at least one ionic moiety, (Bxe2x80x2) an acid and, optionally, (Cxe2x80x2) a flexibilizer. The phenolic novolak dispersion and the flexibilizer can be the same as described above in connection with the primer or coating composition. The aqueous metal treatment composition is described in more detail in commonly-owned U.S. Provisional Patent Application No. 60/072,782 titled xe2x80x9cAqueous Metal Treatment Compositionxe2x80x9d (Attorney Docket No. IR-2486(CE)), filed Jan. 27, 1998 and incorporated herein by reference.
The acid (Bxe2x80x2) of the metal treatment composition can be any acid that is capable of reacting with a metal to generate multivalent ions. Illustrative acids include hydrofluoric acid, phosphoric acid, sulfuric acid, hydrochloric acid and nitric acid. In the case of steel the multivalent ions will be ferric and/or ferrous ions. Aqueous solutions of phosphoric acid are preferred. When the acid is mixed into the composition presumably the respective ions are formed and exist as independent species in addition to the presence of the free acid. In other words, in the case of phosphoric acid, phosphate ions and free phosphoric acid co-exist in the formulated final multi-component composition. The acid preferably is present in an amount of 5 to 300 parts by weight, more preferably 10 to 160 parts by weight, based on 100 parts by weight of the phenolic novolak resin dispersion (Axe2x80x2).
The flexibilizer (Cxe2x80x2) of the metal treatment composition, if present, preferably is included in the composition in an amount of 5 parts by weight to 300 parts by weight, based on 100 parts by weight phenolic novolak resin dispersion (Axe2x80x2). More preferably, the flexibilizer is present in an amount of 25 parts by weight to 100 parts by weight, based on 100 parts by weight the phenolic novolak resin dispersion (Axe2x80x2).
Since the dispersed phenolic resin (Axe2x80x2) of the metal treatment composition is a novolak, a curative must be introduced in order to cure the film formed by the metal treatment composition. The curative can be an aldehyde donor compound that is present in the primer of the invention. When the curative-containing primer is applied over the metal treatment, the curative cures the metal treatment composition. It has been found that the formaldehyde species generated from the resole present in the primer appear to co-cure the novolak in the metal treatment coating via diffusion.
It has also been found that the addition of a control agent to the metal treatment composition described in commonly-owned U.S. Provisional Patent Application No. 60/072,782 titled xe2x80x9cAqueous Metal Treatment Compositionxe2x80x9d dramatically improves uniform coating formation on more complex surface topography and enhances the autodeposition of subsequently-applied compositions thus improving corrosion resistance and overall robustness. The protective coating formed by the composition of the invention is particularly useful for providing corrosion resistance to metal substrates that are subjected to significant stresses and/or strains causing significant flexing or movement of the substrate surface. Due to the improved deposition caused by the control agent, the concentration of active ingredients in an autodepositable composition that includes the control agent can be reduced. Another advantage of the invention is that there is no need to post-rinse the treated surface in order to remove any control agent residue. Furthermore, the control agent eliminates or substantially eliminates the ambient staging period thus improving process efficiency.
The control agent is any material that is able to improve the formation of an autodeposited coating on a metallic surface and, optionally, improve the formation of another autodeposited coating (such as the primer or coating of the invention) applied after the control agent-containing autodeposited coating. Addition of the control agent also increases the uniformity of the thickness of the autodeposited coating. The control agent-containing composition does not require an ambient staging period in order to develop fully the coating. In other words, the metallic coating conversion is complete upon drying of the coated substrate and any subsequent coating, primer or adhesive compositions can be applied immediately after coating and drying of the control agent-containing composition. The control agent also must be compatible with the other components of the composition under acidic conditions without prematurely coagulating or destabilizing the composition.
The control agent may be a nitro compound, a nitroso compound, an oxime compound, a nitrate compound, or a similar material. A mixture of control agents may be used. Organic nitro compounds are the preferred control agents.
The organic nitro compound is any material that includes a nitro group (xe2x80x94NO2) bonded to an organic moiety. Preferably, the organic nitro compound is water soluble or, if water insoluble, capable of being dispersed in water. Illustrative organic nitro compounds include nitroguanidine; aromatic nitrosulfonates such as nitro or dinitrobenzenesulfonate and the salts thereof such as sodium, potassium, amine or any monovalent metal ion (particularly the sodium salt of 3,5-dinitrobenzenesulfonate); Naphthol Yellow S; and picric acid (also known as trinitrophenol). Especially preferred for commercial availability and regulatory reasons is a mixture of nitroguanidine and sodium nitrobenzenesulfonate.
The amount of control agent(s) in the metal treatment composition may vary, particularly depending upon the amount of any acid in the composition. Preferably, the amount is up to 20 weight %, more preferably up to 10 weight %, and most preferably 2 to 5 weight %, based on the total amount of non-volatile ingredients in the metal treatment composition. According to a preferred embodiment, the weight ratio of nitroguanidine to sodium nitrobenzenesulfonate should range from 1:10 to 5:1.
The organic nitro compound typically is mixed into the composition in the form of an aqueous solution or dispersion. For example, nitroguanidine is a solid at room temperature and is dissolved in water prior to formulating into the composition.
If conventional applications methods are used for the primer or coating of the invention, the metallic surface may be pre-treated prior to application of the composition via well-known conversion techniques. Conversion coating generally involves treating the surface with chemicals that form a metal phosphate and/or metal oxide conversion coating on the metal surface. The conversion coating provides protection against corrosion and can enhance adhesion of any subsequent coatings. Phosphatizing is an example of a well-established conversion process. Another conversion process is applying the above-described metal treatment composition.
Curing of the primer or coating composition to form a highly crosslinked thermoset on the metallic surface can be accomplished by heating. The degree of heating will vary depending upon the specific composition, but in general the coated composition should be exposed to a temperature of 250 to 400xc2x0 F. for 5 minutes to one hour.
The primer composition can be used to bond any types of adherends together, but it is particularly useful to bond a metal surface to a polymeric material surface. The polymeric material can be any elastomeric material selected from any of the natural rubbers and olefinic synthetic rubbers including polychloroprene, polybutadiene, neoprene, styrene-butadiene copolymer rubber, acrylonitrile-butadiene copolymer rubber, ethylene-propylene copolymer rubber (EPM), ethylene-propylene-diene terpolymer rubber (EPDM), butyl rubber, brominated butyl rubber, alkylated chlorosulfonated polyethylene and the like. The material may also be a thermoplastic elastomer such as those sold under the trade designations SANTOPRENE and ALCRYN by Monsanto and DuPont, respectively. The metal surface may be selected from any of the common structural metals such as iron, steel (including stainless steel and electrogalvanized steel), lead, aluminum, copper, brass, bronze, MONEL metal alloy, nickel, zinc and the like.
For adhesive bonding, the primer composition typically is applied to the metal surface and then dried. The covercoat then is applied to the primer-coated metal surface and the coated metal surface and elastomeric surface are brought together under heat and pressure to complete the bonding procedure. The exact conditions selected will depend upon the particular elastomer being bonded and whether or not it is cured prior to bonding. In some cases, it may be desirable to heat the metal surface prior to application of the primer and/or covercoat composition(s) to assist in drying of the composition(s). The coated metal surface and the elastomeric surface are typically brought together under a pressure of 20 to 175 MPa, preferably from 20 to 50 MPa. If the elastomer is uncured, the resulting elastomer-metal assembly is simultaneously heated to a temperature of 140xc2x0 C. to 220xc2x0 C., preferably 160xc2x0 C. to 200xc2x0 C. The assembly should remain under the applied pressure and temperature for a period of 1 minute to 60 minutes, depending on the cure rate and thickness of the elastomeric substrate. If the elastomer is already cured, the bonding temperature may range from 90xc2x0 C. to above 180xc2x0 C. for 15 to 120 minutes.
The bonding process may be carried out by introducing the elastomer as a semi-molten material to the metal surface as in, for example, an injection-molding process. The process may also be carried out by utilizing compression molding, transfer molding or autoclave curing techniques. After the process is complete, the bond is fully vulcanized and ready for use in a final application.
The covercoat can essentially be any polymeric material-adhering adhesive, such as those described in U.S. Pat. Nos. 3,258; 3,258,389; 4,119,587; 5,200,459; 5,300,555 and 5,496,884. Elastomer-to-metal adhesive covercoats are commercially available from Lord Corporation.
The invention will be described in more detail by way of the following non-limiting examples. The failure mechanism for the tested bond is expressed in terms of percent. A high percent of rubber retained (R) on the metal coupon is desirable since this indicates that the adhesive bond is stronger than the rubber itself. Rubber-cement failure (RC) indicates the percentage of failure at the interface between the rubber and the adhesive. Cement-metal failure (CM) indicates the percentage of failure at the interface between the metal substrate and the adhesive.
For the boiling water test the bonded test assemblies or coupons were prepared according to ASTM-D-429-B. The leading edge of each of the assemblies was stressed by suspending a two kg weight on the overlapping rubber tail and the assembly was then mounted in a fixture so that the rubber tail was at an approximately 90xc2x0 angle to the plane formed by the bonded interface. The stressed edge interface was exposed to boiling water by immersing the coupon in boiling water for the indicated time period. After this time, the coupons were removed from the boiling water, allowed to cool and tested on either an Instron mechanical tester by pulling the rubber off the metal at a 45xc2x0 angle stripping fixture with a crosshead speed of 2 inches per minute or by manually peeling the rubber from the metal substrate. The amount of rubber retained on the bonded area is recorded as a percentage as described above.
For the salt spray test the bonded test assemblies prepared according to ASTM-D-429-B were buffed on the edges with a grinding wheel. The rubber is then tied back over the metal with stainless steel wire so as to stress the bonded area. This exposes the bond line to the environment. The assemblies then are strung on stainless steel wire and placed in a salt spray chamber. The environment inside the chamber is 100xc2x0 F., 100 percent relative humidity and 5 percent dissolved salt in the spray, which is dispersed throughout the chamber. The assemblies remain in this environment for the indicated time period. Upon removal, the rubber is peeled manually from the metal substrate. The amount of rubber retained on the bonded area is recorded as a percentage as described above. | {
"pile_set_name": "USPTO Backgrounds"
} |
This invention relates to a non-volatile semiconductor memory device.
A ROM capable of electrically erasing the stored contents and rewriting them is known as an EEPROM (Electrically Erasable Programmable ROM). Unlike EPROMs of the ultraviolet light erasable type, such EEPROMs mounted on a board can erase data by an electric signal alone. For this reason, EEPROMs are frequently used for various controls or memory cards.
FIG. 1 is a cross sectional view showing the device structure of a typical memory cell in the EEPROM, and FIG. 2 is an equivalent circuit diagram thereof. In FIG. 1, for example, on a P-type substrate 80, N-type diffused regions 91, 92 and 93 are provided. Between the diffused regions 91 and 92 on the substrate 80, a floating gate electrode 95 formed of a polycrystalline silicon layer of the first layer is provided on an insulating oxide film 94. This floating gate electrode 95 overlaps with the N-type diffused region 92 through a thin film portion 94A of the insulating oxide film 94. On the floating gate electrode 95, a gate electrode 97 formed of a polycrystalline silicon layer of the second layer is provided on an insulating oxide film 96. Further, between the diffused regions 92 and 93 on the substrate 80, a gate electrode 99 formed of a polycrystalline silicon layer is provided on an insulating oxide film 98.
The memory cell of FIG. 1 includes two transistors 1 and 2. Namely, one is a transistor 2 having a floating gate (called floating gate transistor hereinafter) as a non-volatile memory element having the N-type diffused region 91 as the source, the N-type diffused region 92 as the drain, the floating gate electrode 95 as the floating gate, and the gate electrode 97 as the control gate. The other is a select transistor 1 of enhancement type having the N-type diffused region 92 as the source, the N-type diffused region 93 as the drain, and the gate electrode 99 as the gate. These transistors 1 and 2 are connected in series. As indicated by the equivalent circuit of FIG. 2, the drain and the gate of the transistor 1 are used as the data line DL and the word line WL, respectively. The floating gate and the control gate of the floating gate transistor 2 are used as the floating gate FG and the control gate CG, respectively, and the source of the floating gate transistor 2 is used as the source S. It is to be noted that the memory cell of FIG. 1 constitutes a one bit data memory unit (memory element) for storing data of one bit.
In the memory cell using a floating gate transistor as described above, as long as data erasing is not conducted, data once written is permanently held from an ideal point of view. However, in the case of an actual memory cell, after erasing or writing of data is carried out, charges in the floating gate are discharged with the lapse of time, and the stored data disappears. Particularly in the case of a cell where there is some defect in an insulating oxide film, etc., this charge dissipation occurs to a considerable degree. According to these circumstances, the memory cell becomes defective when used.
Generally, as a technique for evaluating the holding characteristic of stored data, there is known a method of placing the memory cell in a high temperature state to accelerate the rate of occurrence of such deterioration. This method is called a high temperature shelf test. FIG. 3 is a characteristic curve showing changes in the threshold voltage (V.sub.th) of the floating gate transistor when the high temperature shelf test is conducted at 300.degree. C. The threshold voltage in an initial state is about 1 volt as indicated by a broken line.
The case where electrons are discharged from the floating gate to store data of the "0" level will be first described. At this time, the threshold voltage of the floating gate transistor takes a substantially negative value, e.g., -5 volts. For this reason, a current flows even if the potential on the control gate is zero volts.
The case where electrons are injected into the floating gate to store data of "1" level will now be described. The threshold voltage of the floating gate transistor takes a substantially high value, e.g., +10 volts.
At the time of readout of data, the potential on the control gate is set to zero volts. The judgment as to whether the data stored in the memory cell is "0" or "1" is carried out by setting the operating point of the sense amplifier circuit, i.e., sense potential so that a suitable current flows in the memory cell. This sense potential is set to about -1 volt as indicated by the single dotted lines.
In FIG. 3, in the case of the cell of "1" data, electrons in the floating gate are discharged with the lapse of time. Thus, the threshold voltage thereof lowers with the lapse of time to reach 1 volt, which is the threshold voltage in the initial state. On the other hand, in the case of the cell of "0" data, electrons are injected into the floating gate with the lapse of time. Thus, the threshold voltage rises with the lapse of time to reach 1 volt. At the time t.sub.N in the middle thereof, that threshold voltage goes through '1 volt, which is the sense potential of the sense amplifier circuit.
FIG. 4 shows the change of the cell current (I.sub.cell) at the time of the high temperature shelf test of the memory cell in which "0" level data is stored. With the lapse of time, the cell current decreases. When the cell current is below the sense level current Is in the sense amplifier circuit, the sense amplifier circuit erroneously judges data which has been originally at the "0" level to be "1" level data. It is only the memory cells in which "0" level data is stored, that data may be erroneously detected as stated above. The time when such an erroneous data is detected is now assumed to be t.sub.N. In the case of the normal memory cell, the time required for reaching the time t.sub.N is sufficiently long, and there is therefore no problem in view of actual use. However, in the case of the defective memory cell, the time required for reaching the time t.sub.N is small. For this reason, there are instances where memory cells may become inferior or defective while they are being used in a product. Particularly, if erasing and/or writing are frequently repeated, the insulating oxide film is considerably deteriorated, so inferiority is apt to occur.
FIG. 5 is a circuit diagram of a conventional typical EEPROM in which memory cells similar to the memory cell shown by the equivalent circuit of FIG. 2 are used to constitute a cell array. The control gates of the floating gate transistors 2 of memory cells MC-11 to MC-mn are connected to control gate select lines CGL1 to CGLn selected by column decoders 5-1 to 5-n through control gate select transistors 6. Further, the gate of the control gate select transistor 6 and the gate of the select transistor 1 in each same memory cell are both connected to one of the row lines WL1 to WLm selected by the row decoder 4. Drains of the select transistors 1 in respective memory cells are connected to column lines DL1 to DLn. Respective column lines DL1 to DLn are connected in common to a bus line 8 through column select transistors 7. The gates of the transistors 7 are connected to the corresponding column decoders 5 through column select lines CL1 to CLn, respectively. To the bus line 8, a data input circuit 9 and a sense amplifier circuit 10 are connected. The data input circuit 9 outputs data of "0" or "1" level depending on a write data signal Din inputted from the outside. The sense amplifier circuit 10 detects, as "0" or "1", the level of data stored in a selected memory cell MC. At the time of sensing the data level, the sense amplifier circuit 10 applies a bias voltage necessary for the readout of data to a corresponding data line DL. Namely, the sense amplifier circuit 10 includes a bias circuit.
The data sensed at the sense amplifier circuit 10 is inputted to a data output circuit 12. Readout data is outputted from the data output circuit 12 to the outside.
In EEPROMs of such a structure, in the case where erasing/writing were conducted about 10.sup.3 times with a device of a memory capacity of the order of 64K bits, the possibility that there takes place random cell inferiority in every bit due to defects as described above, etc., indicates a high value of about 0.1 to 0.2%. For this reason, there was the drawback that the reliability is low, leading to limited use from a viewpoint of the practical use.
To prevent lowering of the reliability due to cell inferiority, a technique is conceivable to constitute each storage unit with two memory cells. However, the memory cell corresponding to 1 bit becomes large, resulting in that such a technique is not suitable for implementation of large capacity memory devices. | {
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Fuel reformers reform hydrocarbon fuel into a reformate gas such as hydrogen-rich gas. In the case of an onboard fuel reformer or a fuel reformer associated with a stationary power generator, the reformate gas produced by the fuel reformer may be utilized as fuel or fuel additive in the operation of an internal combustion engine. The reformate gas may also be utilized to regenerate or otherwise condition an emission abatement device associated with an internal combustion engine or as a fuel for a fuel cell. | {
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1. Field of the Invention
The present invention relates to a process of producing palladium-alkali or palladium/promoter metal/alkali metal catalysts useful in the oxacylation of olefins or diolefins. In particular, effecting the production of vinyl acetate from ethylene, acetic acid and an oxygen containing gas. More particular, the present invention relates to the process of producing palladium-gold-potassium fluid bed catalyst useful in the manufacture of vinyl acetate.
The production of vinyl acetate by reacting ethylene, acetic acid and oxygen together in the gas-phase in the presence of a catalyst containing palladium, gold and an alkali metal acetate promoter is known. The catalyst components are typically supported on a porous carrier material such as silica or alumina.
In early examples of these catalysts, both the palladium and gold were distributed more or less uniformly throughout the carrier (see for example U.S. Pat. Nos. 3,275,680, 3,743,607 and 3,950,400 and GB 1333449). This was subsequently recognized to be a disadvantage since it was found that the material within the inner part of the carrier did not contribute to the reaction since the reactants did not diffuse significantly into the carrier before reaction occurred. In other words, a significant amount of the palladium and gold never came into contact with the reactants.
In order to overcome this problem, new methods of catalyst manufacture were devised with the aim of producing catalysts in which the active components were concentrated in the outermost shell of the support (shell impregnated catalysts). For example, GB Patent No.1500167 claims catalysts in which at least 90% of the palladium and gold is distributed in that part of the carrier particle which is not more than 30% of the particle radius from the surface. GB Patent No. 1283737 teaches that the degree of penetration into the porous carrier can be controlled by pretreating the porous carrier with an alkaline solution of, for example, sodium carbonate or sodium hydroxide.
Another approach which has been found to produce particularly active catalysts is described in U.S. Pat. No. 4,048,096. In this patent shell impregnated catalysts are produced by a process comprising the steps of (1) impregnating a carrier with aqueous solutions of water-soluble palladium and gold compounds, the total volume of the solutions being 95 to 100% of the absorptive capacity of the catalyst support, (2) precipitating water-insoluble palladium and gold compounds on the carrier by soaking the impregnated carrier in a solution of an alkali metal silicate, the amount of alkali metal silicate being such that, after the alkali metal silicate has been in contact with the carrier for 12 to 24 hours, the pH of the solution is from 6.5 to 9.5; (3) converting the water-soluble palladium and gold compounds into palladium and gold metal by treatment with a reducing agent; (4) washing with water; (5) contacting the catalyst with alkali metal acetate and (6) drying the catalyst. Using this method, catalysts having a specific activity of at least 83 grams of vinyl acetate per gram of precious metal per hour measured at 150.degree. C. can allegedly be obtained. Shell impregnated catalyst are also disclosed in U.S. Pat. No. 4,087,622. Finally, U.S. Pat. No. 5,185,308 also discloses shell impregnated Pd-Au catalyst and the process of manufacture. Each of the above patents is primarily concerned with the manufacture of fixed bed catalyst useful in the manufacture of vinyl acetate.
It would be economically beneficial if the oxacylation of olefins or diolefins, in particular the manufacture of vinyl acetate from ethylene, acetic acid and oxygen could be performed in a fluid bed process. However, until the discovery of the process of the present invention, the preparation of Pd-Au-alkali metal catalyst in fluid bed form has not led to a catalyst having the necessary properties which can lead to an economically viable fluid bed process for the manufacture of vinyl acetate. | {
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1. Field
Exemplary embodiments of the present disclosure relate to a memory system, and more particularly to a memory system having a media quality aware Error-Correcting Code (ECC) decoding selection and operating method thereof.
2. Description of the Related Art
The use of computer systems has been rapidly increased in the digital era. Due to this fact, the reliability of digital data storage, such as a memory system, is critical.
Electrical or magnetic interference inside the computer system can cause a single bit of memory cells of the memory system to spontaneously flip to the opposite state to cause errors and result in internal data corruption.
Bit errors of a memory system can be caused by degradation of internal NAND memory structures from previous repeated accesses. In this case, the NAND is wearing out and not getting high energy particle disturbance like a Synchronous Dynamic Random-Access Memory (SDRAM) type of memory.
The memory system, or storage devices having an ECC controller is a type of computer data storage that can detect and correct the most common kinds of the internal data corruption. The memory system having the ECC controller is used in most computers where data corruption cannot be tolerated under any circumstances.
Typically, the ECC controller maintains the memory system immune to single-bit errors, the data that is read from each word is always the same as the data that has been written to, even if one or more bits actually stored have been flipped to the wrong state. While the memory system having the ECC controller can detect and correct the errors, most non-ECC memory system cannot correct errors although some may support error detection but not correction.
Thus, there remains a need for a memory system having the ECC controller and the operating method thereof. In view of the ever-increasing need to improve performance and security, it is more and more critical that answers be found to these problems. Solutions to these problems have been long sought but prior developments have not taught or suggested any solutions and, thus, solutions to these problems have long eluded those skilled in the art. | {
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1. Field of the Invention
The present invention relates generally to the field of graphics processing and more specifically to a system and method for switching between graphical processing units.
2. Description of the Related Art
A typical computing system includes a central processing unit (CPU), a graphics processing unit (GPU), a system memory, a display device, and an input device. A variety of software applications may run on the computing system. The CPU usually executes the overall structure of the software application and configures the GPU to perform specific tasks in the graphics pipeline (the collection of processing steps performed to transform 3-D images into 2-D images). Some software applications, such as web browsers and word processors, perform well on most computing systems. Other software applications, such as modern 3-D games and video processors, are more graphics-intensive and may perform better on computing systems which include a relatively high performance GPU with a rich graphics feature set.
GPUs typically exhibit a trade-off between graphics performance and power consumption; GPUs with higher performance usually consume more power than GPUs with lower performance. This trade-off is exemplified by two types of GPUs: discrete GPUs (DGPUs) and integrated GPUs (IGPUs). A DGPU is often part of a discrete graphics card that includes dedicated memory and is plugged into a slot in the computing system. An IGPU is part of the main chipset that is wired into the motherboard of the computing system and may share the system memory with the CPU. Typically, a DGPU has higher performance, but consumes more power than an IGPU. For running graphics-intensive software applications, a DPGU may be preferred. However, for running less demanding software applications on a laptop, an IGPU may provide adequate performance while maximizing the battery life.
Some computing systems include both a DGPU and an IGPU, allowing the user to tune the graphics performance and the power consumption of the computing system based on the situation. In such a computing system, the user may choose to maximize graphics performance by using the DGPU or to minimize power consumption by using the IGPU. In one approach to setting the desired graphics performance, the user attaches the display to the desired GPU. In such an approach, to switch from the high-performance DGPU to the power-saving IGPU, the user manually unplugs the display device from the video connector for the DGPU and subsequently the user plugs the display device into the video connector for the IGPU. One drawback to this approach, however, is that it is manually intensive and time consuming. In addition, the display will be blank during the GPU transition. In another approach, a manual switch is used to select between the DGPU and the IGPU, then the computing system is rebooted to effect the GPU change. This solution reduces the manual effort, but such a solution does not necessarily reduce the time required to switch between the GPUs. Furthermore, any running applications will terminate when the computing system is rebooted.
As the foregoing illustrates, what is needed in the art is a more flexible technique for switching between an IGPU and a DGPU in a computing system. | {
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Rotary wing aircraft can be either powered or unpowered. The unpowered version saw substantial development first. Its practical development came at the hands of Juan de la Cierva working in France shortly after the Wright Brothers. Mr. Pitcaren, an American, purchased a French gyroplane and continued to advance the state of the art. The first production models included a horizontally disposed unpowered rotor having a hub mounted upon the top of a rigid mast that was in turn rigidly affixed atop a small airplane. The airplane portion of the autogyro also employed an engine and tractor propeller for propulsion. Vertical and horizontal stabilizers as well as the wings were necessary for attitude and direction control.
Takeoff was accomplished by the Pitcaren machine by taxiing the craft at an angle of attack to allow air to pass upwardly through the rotor thus causing rotation. As the aircraft continued to move forward, rotation increased until enough lift was produced for takeoff. In reality, the distance required for takeoff was excessive. As is shown in ELEMENTS OF PRACTICAL AERODYNAMICS by Bradley Jones, M.S., John Wiley and Sons, Inc., N.Y., 1936, the rotor blade was brought up to speed prior to ground roll by a power takeoff shaft that was clutched to the propulsion engine. As rotor lift neared vehicle weight, the body of the craft would begin to rotate in response to rotor torque. At this point the power takeoff clutch was disengaged, brakes released and thrust applied to produce a reasonably short takeoff run.
A jump takeoff was accomplished by the Pitcaren machine by adding collective pitch control to the rotor blades, permitting the rotors to come up to full speed with zero lift. Since a gyroplane has no means for counteracting powered rotor torque, it was still necessary to disengage the power takeoff clutch before leaving the ground. With the rotor spinning at top speed, the collective pitch control was moved from zero to maximum lift to accelerate the craft vertically into the air using the stored energy of the rotor, while forward propulsion accelerated the craft into horizontal flight with normal autorotation ensuing.
Pitcaren also discovered that pitch and roll control could be accomplished by supporting the aircraft below the rotor like a pendulum, thus eliminating the necessity for wings and horizontal stabilizer. This brought attractive simplicity and the gyroplane became an autogyro.
As is described in the aforementioned reference, ELEMENTS OF PRACTICAL AERODYNAMICS, the gimbaled and hinged rotor with powered spin-up was the state of the art in 1936 pertaining to autogyros. Cyclic pitch was apparently added shortly thereafter. During the 1940's the Armed Forces became interested in an aircraft that could hover and even fly backward. At that time Igor Sikorsky was flying a powered rotor machine or helicopter but was blocked in development efforts because Pitcaren owned the dominating patents on rotary wing aircraft. The government subsequently ordered Pitcaren to allow Mr. Sikorsky the use of his patents in order to bring helicopter technology to the level of government objectives. As a consequence helicopters and not autogyros came into common use and remain so to this date. The fact that a helicopter can hover and an autogyro cannot hover contributed to this trend.
Now a helicopter is a powered rotary wing aircraft employing collective and cyclic pitch for stability and control and a tail rotor for antitorque and directional control. As in the autogyro, hinged rotor blades are also employed to reduce or eliminate cyclic stresses developed during forward flight. The antitorque rotor represents a sizeable power loss and developers over the years have sought to eliminate it. This can be accomplished by employing propulsion means on the rotor tips or by using counter-rotating rotors.
With respect to propulsion means on the rotor tips, a European company built an aircraft called to Rotodyne during the 1950's. It was a gyroplane that employed ramjet engines on the rotor tips for powered takeoff, hovering and descent if desired. Since ramjets cannot start themselves, propulsion engine bleed air was ducted up the mast and out the blades to activate the ramjets. During the 1960's Hughes Aircraft Co. was building a hot cycle research helicopter according to "Aviation Week and Space Technology", June 22, 1964, page (cover). Also, Hiller Aircraft Co. was testing a tip-mounted turbojet according to "Aviation Week and Space Technology," Aug. 10, 1964, page 10.
With respect to counter-rotating rotors the following U.S. Patents are representative of the prior art: 1,403,909, 1/17/1922, G. E. Moir; 1,849,943, 3/15/1932, R. J. McLaughlin; 3,395,876, 8/6/1968, J. B. Green. The U.S. Navy flew a counter-rotating coaxial shaft drone helicopter as a torpedo delivery system before rocket launched torpedoes came into use. The only practical counter-rotating helicopters utilize separate shafts for each rotor disc.
The idea of combining counter-rotating rotors and tip propulsion has also been explored in U.S. Pat. No. 4,589,611, 5/20/1986, Ramme.
The above described methods for eliminating the tail rotor of a helicopter involve considerable complexity and expense and as yet have not in commercial practice replaced the standard single rotor helicopter having a tail rotor.
The present invention seeks to achieve the simplicity of the autogyro and the performance capabilities of a helicopter. Earlier workers appreciated how difficult this was to do. If a counter-rotating rotor assembly were gimbal mounted atop an autogyro then power could be applied to or deleted from the rotor without any torque problems. Assymetric lift would cease to be a problem. The rotor blades would still have to be hinged to reduce or eliminate cyclic stresses at the hub. The blades would not be as long as those of a single rotor assembly, but would still be long enough to require a substantial vertical separation between the counter-rotating blade discs to keep the tips from running into each other. The U.S. Navy counter-rotating helicopter drone demonstrated this reality very clearly with substantial vertical separation between the rotor discs. Combining such a tall rotor assembly with a gimbal mounted fuselage gives rise to many questions concerning control forces and to my knowledge has not been attempted. I reasoned that if the vertical separation could be reduced, or for all practical purposes eliminated, and a round disc supported structure provided, then an attractive hovering autogyro efficient in forward flight could be envisioned. Elimination of the vertical separation between rotor discs would require stiff rotor blades fixedly attached to a hub. A stiff rotor blade tends to look like the wing of an aircraft in order to resist root bending moments which are cyclic. Consequently long stiff blades are not desirable.
This invention provides an autogyro incorporating a pair of closely spaced rigid counter-rotating circular planform wings or disc structures integral with closely spaced sets of peripherally distributed rotor blades with means for applying power to the rotors for vertical takeoff, landing and hovering. | {
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A network packet carries data via protocols that the Internet uses, such as Transmission Control Protocol/Internet Protocol/Ethernet Protocol (TCP/IP/Ethernet). A typical switch is able to modify various fields of incoming packets prior to sending the packets out to a destination or to another switch. Incoming packets are modified for various reasons, such as where the packets are being forwarded to, the protocol the destination supports, priority of the packets, incoming format of the protocol header, etc. Since network protocols are evolving, one or more fields of a protocol header can be optional, which complicates the hardware of the switch as a given field within a protocol header may not be always at a fixed offset.
During modification of a packet, the prior art switch linearly processes each protocol layer in the packet. Such processing can create network related performance issues, including latency, which can cause an implementation to overprovision processing resources. | {
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The present invention relates to an improvement of the method of analysis by on-line gas phase chromatography of a substantially gaseous phase produced by an industrial olefin polymerisation plant.
The literature describes methods of analysis by chromatography. There will be cited, as an example, BOMBAUGH Karl, J. Chromatography, Gas and Liquid. MacKetta Encyclopedia of Chemical Processing and Design. 1979, Vol. 8, pages 270-285.
The major problem encountered with said known methods consists in the difficulty of implementing the method on line on an industrial scale, and also in the reliability of the resulting analyses over time.
For example, drifts of the analyses of the gas phase frequently have to be dealt with, which are due in part to partial blockages of the chromatography analysis lines used in industrial plants for producing polyethylene in gas phase in a fluidised bed reactor. | {
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1. Field of the Invention
This invention pertains in general to a system and method for processing residual gas and, more particularly, to a system and method for processing and disposing of residual toxic gas in a semiconductor manufacturing process.
2. Description of the Related Art
A variety of process gases are used in various process equipment in a semiconductor manufacturing process. For example, a Chemical Vapor Deposition (CVD) process often uses SiH4, B2H6, NH3 and H2 as process gases. Because many process gases are toxic and explosive, and because process gases are seldom completely reacted during a manufacturing process, handling of residual gases, i.e. process gases that remain after completion of the manufacturing process, is an important issue in semiconductor manufacturing. In addition, environmental concerns and government legislating prohibit toxic gases and harmful particles from being vented to the atmosphere or disposed of with waste water.
FIG. 1 is a flow chart of a conventional process for handling residual gas in a semiconductor manufacturing process that uses silane (SiH4) as the processing gas. Referring to FIG. 1, process gas, for example, silane, is selected at step 1. Some of the characteristics of silane gas are described in the following table:
AtomicBoilingMoleculeNameWeightColorSmellpoint (° C.)SiH4Silane32NoneRepulsive−112MeltingStatus inPointDensityRoomSafety(° C.)(g/L)TemperatureCharacteristicsToxic Indication**−1850.68GasE/F/P*TLVIDLH5 ppm—*E: explosive; F: inflammable; P: toxic**TLV: Threshold Limit Value (time weighted average exposure for an 8-hour day in a 40-hour workweek)IDLH: Immediate Danger to Life and Health
Source: R. J. Lewis, Sr., Hazardous Chemicals Desk Reference, 3rd Ed., Van Nostrand Reinhold, 1993.
These characteristics show that silane is toxic and explosive, and therefore great care should be taken in handling and disposing of silane gas. The process gas is then introduced at step 10 to a process chamber through a connecting pipe. After a semiconductor manufacturing process is performed in the process chamber at step 10, a pump propels the remaining silane gas that did not fully react during the process, i.e., the residual gas, from the process chamber to a wet scrubber through another connecting pipe at step 20. As described above, the residual gas introduced to the wet scrubber still contains non-reacted silane gas. Upon entering the wet scrubber, oxidation ensues and powdered silicon dioxide (SiO2) is formed. Water is then added to the wet scrubber so that both soluble and non-soluble SiO2 powders are further processed at a waste water facility drain at step 42. The resultant waste water is expelled to the environment. Any remaining residual gas and powders are vented at step 40 to a waste gas facility exhaust to be further processed and then be expelled into the atmosphere.
This conventional technique, however, cannot ensure that all of the silane gas that passes through the wet scrubber is reacted. Therefore, an explosion is still possible if the silane gas were to come into contact with oxygen in one of the connecting pipes. Furthermore, the non-reacted silane gas expelled to the atmosphere may still exhibit a toxic level higher than the legally prescribed safety level. In addition, the powders produced through oxidation of the silane gas may result in the blockage of inlets and outlets to and from the wet scrubber.
As a proposed improvement to ensure complete reaction of the residual gas, an alternative conventional technique employs catalysts to breakdown the residual gas, or absorbents to absorb toxic materials or particles so that the gas expelled into the atmosphere is harmless. Such a method, however, requires complex chemical reaction processes. In addition, catalysts and absorbents are usually expensive and cannot be repeatedly used, resulting in an additional cost to the manufacturing process. Moreover, the catalysts and absorbents themselves become toxic from the process and become industrial wastes, of which cannot be easily disposed. | {
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The invention resides in the field of continuous production of liquid food products from a variety of solid foods such as plant seeds, legumes, etc., which liquid food products contain no substantial objectionable off-flavor volatiles.
To be generally acceptable, the foods need not only be nutritious, functional and economical but also be attractive in color, aroma, taste and texture. Plant protein preparations mainly from legumes and nuts, like soybeans, have unacceptable off-flavor volatiles and score heavily against their positive properties and limit their use. Lipoxygenase enzyme has been recognized as the major cause of off-flavor volatiles in most vegetable protein sources including soybeans, peas and peanuts. Extraction of soymilk from soybeans, for example, involves grinding of soybeans in water. The lipoxygenase enzymes released from soybean catalyses reactions among water, oxygen and lipids. Some of the reaction products give off strong beany off-flavor volatiles.
Existing methods deal with the problem of beany off-flavors by thermally and/or chemically inactivating lipoxygenase enzyme in soybeans prior to or during the grinding operation under ambient pressure. For example, because at temperature above 65xc2x0 C., the half-lives of the various lipoxygenase enzymes rapidly decrease with increasing temperature, heating soybeans above this temperature effectively inactivates lipoxygenase enzyme. Hot grinding of soybeans performs the desired inactivation of the enzyme. Ground soybean slurry can now be further processed without any further problem of off-flavor generation. However, the thermal inactivation of enzyme causes other proteins in soybeans also to prematurely denature and get attached to the fibers in the beans. The extraction of proteins in water thus becomes difficult and leads to reduced yield and chalky mouth-feel. The latter is caused due to fine fibers getting into the liquid extract.
Control of off-flavor volatiles has also been achieved by eliminating available free oxygen under ambient or reduced pressure during the grinding oDeration. The present inventor""s earlier U.S. Pat. No. 4,915,972 Apr. 10, 1990 describes a process for preparing protein foods by disintegrating the seeds such as soybeans, peanuts etc., in an oxygen-free environment, thus preventing lipoxygenase enzyme from producing the off-flavor volatiles. This process dispenses with the enzyme inactivation by heat treatment.
Another U.S. Pat. No. 4,744,524 May 17, 1988 by the present inventor describes an equipment which grinds soybeans in an oxygen-free environment. The equipment further cooks and separates the soybean slurry to extract soymilk which has no beany flavor.
U.S. Pat. No. 3,937,843 Feb. 10, 1976 Osaka et al describes bean-odor-free soy bean product and its production. The patent uses lactic fermentation of soy milk.
FIG. 1 illustrates schematically a system for continuously producing soymilks with prior art. Referring to the figure, a rotary valve or auger 10 regulates the feeding of soybeans from a soybean hopper 12. The soybeans in the hopper may be dry soybeans or may have already been properly soaked. A regulated amount of hot or cold water is added to the soybeans and the mixture is sent to a grinder 14 that grinds soybeans. When hot water is used for grinding and/or steam is injected between the rotary valve 12 and grinder 14, the lipoxygenase enzyme is partly inactivated and controls beany off-flavor. The hopper 12 may also have water feed and level control for airless feeding and grinding of soybeans. A steam mixer 16 is provided to heat the soybean slurry to a preset temperature. A positive displacement pump (PDP) 18 regulates the slurry flow. A holding tube 20 ensures that the soybeans slurry is properly cooked by maintaining the steam-soybeans slurry mixture at the preset temperatures for a preset duration. A vacuum deodorizer 22 removes the volatiles that may be present in the cooked slurry. A back-pressure valve 24 ensures the maintenance of high pressure and high temperature in the holding tube and a low pressure in the vacuum deodorizer. A PDP 26 sends a regulated amount of cooked slurry to an extractor 28 which separates soymilk and fibrous residue. The extractor can be a centrifugal filter, decanter, filter press, or any other separation device. Soymilk 30 with reduced beany off-flavor volatile is pumped with a PDP 32 for packaging or other processing.
FIG. 2 shows schematically an alternative system similar to that shown in FIG. 1. In the figure, an extractor 40 is moved upstream so that the slurry is separated into liquid and fibrous residue, and only the liquid is cooked with steam in the steam mixer 42. The cooked liquid is held under pressure in a holding tube 44 to ensure a proper cooking at a proper temperature before it is led to a vacuum deodorizer 46.
The methods described thus far for continuously producing non-beany flavor soymilk inactivate the lipoxygenase enzyme thermally or by creating oxygen-free grinding environment. They involve multiple well-controlled steps before soymilk is extracted and ready for further processing. Any departure from the limited range of the operating parameters leads to the degradation of the quality and yield of soymilk. As a result, existing methods are either capital or manpower intensive, and are not easy to adapt to small-scale continuous production with low cost equipment.
In accordance with one aspect, the present invention is a process amenable to low cost equipment for making liquid food products with no substantial off-flavor volatiles in a continuous process at a small as well as large scale.
In one aspect, enzymes that produce off-flavor volatiles are instantaneously inactivated thermally concomitantly with or immediately following disintegration of solid food in water while the disintegration is conducted under pressure. The pressurized disintegration permits the temperature of the resulting slurry to be raised to the desired cooking temperature, which is usually about 100xc2x0 C. or above. Presence or absence of air during disintegration is relatively unimportant.
In another aspect, a system for continuously producing liquid food products with no off-flavor volatiles includes an airless grinder which is operated under pressure so that air leakage is minimized, enabling the use of low cost equipment.
In yet another aspect, the process includes both airless grinding and steam heating operations, which are performed substantially simultaneously under pressure. This simplifies the construction of a system by eliminating some of the components required in the prior art setups. | {
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The subject matter discussed in the background section should not be assumed to be prior art merely as a result of its mention in the background section. Similarly, a problem mentioned in the background section or associated with the subject matter of the background section should not be assumed to have been previously recognized in the prior art. The subject matter in the background section merely represents different approaches, which in and of themselves may also be inventions.
In conventional database systems, users access their data resources in one logical database. A user of such a conventional system typically retrieves data from and stores data on the system using the user's own systems. A user system might remotely access one of a plurality of server systems that might in turn access the database system. Data retrieval from the system might include the issuance of a query from the user system to the database system. The database system might process the request for information received in the query and send to the user system information relevant to the request.
Unfortunately, conventional database approaches might process a query relatively slowly or become inefficient for a variety of reasons if, for example, a relatively large number of users substantially concurrently access the database system. Performance information can be viewed using reports. Reports, however, need to be manually reviewed by a network administrator at regular intervals to identify performance problems. | {
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1. Field of the Invention
Present invention consists of a method and system for providing assistance to a distressed vehicle, preferably a truck, having a damaged wheel component during a travel condition. In particular, the present invention regards a cheaper and faster method to substitute a damaged wheel component, for example a damaged wheel with an inflated tire, to a vehicle during a travel, for example during a travel in a highway or in a position far to every dealer. Said vehicle may be a car, truck, motorcycle, bus, trailer and wheeled equipment.
2. Description of the Related Art
In some cases the vehicles are not provided with a further wheel, for example some trucks are not provided with a further wheel. In these cases the users of said vehicles are not able to complete the travel without an assistance aid.
It is known that many tire company provides assistance service systems for their tire users. Michelin provides an assistance service named “Euroassist” to users which subscribe an agreement.
In particular, said company provides a system comprising a plurality of assistance point and an assistance center. The assistance center receives the calls from a vehicle with the damaged tire and it provides to send one aid units from one of said plurality assistance point to said vehicle. Said aid unit provides to substitute the damaged tire with another new tire. Said new tire is sold at a fixed prize in accordance with the above agreement. Each of the assistance points must have a minimum stock of predetermined tire models. | {
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1. Technical Field
This invention is directed to telephone terminals and, more particularly, a telephone terminal configurable for accessing features available on the terminal through an interactive display arrangement.
2. Description of the Prior Art
With the advent of numerous features now available at many telephone terminals, displays having selectable menu options are being commonly employed to aid users in accessing the features associated with these options. The display technology employed in most telephone displays today is character-based liquid crystal device (LCD) displays. These displays are configured in various array sizes such as, for example, a 2-line by 10-character LCD display, a 3-line by 12-character LCD display and a 4-line by 12-character LCD display. In order to be aesthetically pleasing when incorporated into a telephone housing, these displays tend to be small, typically on the order of one inch in height. Also, in order to provide a reasonable number of characters for information such as caller-ID information and directory access information, a small font size for the characters is generally used. Thus, the numerous available features unfortunately require large amounts of information to be presented on very small displays.
For optimizing the utilization of space on small displays, some telephone terminals use soft key user interfaces. While soft key approaches can increase the flexibility of managing access to numerous features, they require that a portion of the display be dedicated exclusively to this purpose. For example, many telephone terminals dedicate the bottom row of the display for presentation of label screen prompts which correspond to a set of hard keys. Although these screen prompts do improve somewhat the ease with which one uses the display, such a design constrains the amount of space available for presentation of non-menu items, and also constrains the number of soft key choices which may be shown at any given time. Further, existing terminal screen designs typically constrain the maximum number of characters available for menu labels.
The prior art problems are solved in accordance with the present invention which provides an arrangement for dynamically varying how space on a small display is allocated for presentation of various types of user information. This arrangement is more flexible in organizing and presenting information than existing arrangements.
In accordance with an aspect of the invention, the arrangement optimizes utilization of space on small displays by dynamically allocating lines on the display for presentation of status or header-type information as well as menu item-type information. The arrangement configures the display such that lines therein are dedicatable in any combination to displaying these two types of information. By way of example, on a terminal with a 4-line display, one line may be dedicated to status information, and three lines to menu items; or alternatively, two lines may be dedicated to status information and two lines also to menu items. Thus, enhanced flexibility and efficiency are provided through use of this arrangement.
This invention and its mode of operation will be more clearly understood from the following detailed description when read with the appended drawings: | {
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The Internet is a well-known, global network of cooperatively interconnected computer networks. The World Wide Web portion of the Internet is a collection of server computers (referred to as “web sites”) on the Internet, which store hyper text transfer language “HTML” documents that can be publicly accessed by computer users having a connection to the Internet.
Most basically, the Internet comprises a network of computer networks capable of transmitting messages to one another using a common set of operating rules, called communication protocols. Networks comprise addressable devices (computers) connected or “linked” by communication channels. More specifically, the World Wide Web—comprises an amalgamation of linked-together “web pages” accessible by linked web-based users, with the web pages typically presenting information to the user in a graphical fashion.
World Wide Web (“web”) is used herein to refer generally to both (i) a distributed collection of interlinked, user-viewable Hypertext documents (commonly referred to as web documents or web pages) that are accessible via the Internet, and (ii) the client and server software components that provide user access to such documents using standardized Internet protocols. Currently, the primary standard protocol for allowing applications to locate and acquire web documents is hypertext transfer protocol (HTTP), and the web pages are encoded using HTML.
However, the terms “web” and “World Wide Web” are intended to encompass future markup languages and transport protocols that may be used in place of (or in addition to) HTML and HTTP.
A user at an individual web-based device (e.g., a workstation) that wishes to access a web page on the Internet typically does so using a graphical user interface software application known as a “web browser.” A variety of commercial web browsers are currently available. Well-known web browsers include Netscape's Navigator and Microsoft's Internet Explorer. Web browsers function to initiate connections via the Internet to responsive computers known as “web servers” and to receive information from the web servers that is displayed on the user's workstation. Web browsers accordingly support HTTP, the current underlying communications protocol used by the Internet. In addition, web browsers may support other protocols, such as Wireless Application Protocol (WAP) as well as protocols currently used or yet to be developed.
To connect to a desired web site having retrievable information, a user typically enters a network address designated as a Uniform Resource Locator (URL) into the web browser. The URL identifies both the location of the web site and one or more pages of information contained at that web site, the web site being supported by a particular web server. The web page that a URL refers to can be pre-existing or can be generated on demand when requested, depending on the web page in question. At each URL, text, graphics, or other information may be stored on the web server in a predefined hierarchy. The URL address may be supplied by the user in a variety of ways, to include direct keyboard entry of the address, selection of a previously stored “bookmarked” address, or “clicking” on an appropriate hyper-text link appearing on a web browser control bar or on a displayed web page.
Using the URL, the web browser sends a command in the form of a retrieval request to the web server identified in the URL address. For example, when a URL is entered into a web browser, the web browser sends an HTTP command to the designated web server directing the web server to fetch (download), and then transmit, the requested data (web page) identified by the URL. Information displayed to the user is typically organized into pages that are constructed using HTML or other, similar languages such as XML, etc. The transfer of information between the web browser and the web server is done in the context of a client/server relationship with the web browser being a client of the web server.
Most commonly, networks rely on client/server architectures to perform network operations. A mainframe computer, for instance, communicates with a series of client workstations or “dummy” terminals over a series of coextensive interconnections. The interconnections that connect the mainframe with workstations are implemented using any of a variety of technologies, including various forms of physical medium, such as copper wire (“twisted-pair”), coaxial cable and fiber optic cable, and wireless, electromagnetic transmission either at low-level, such as microwave links and cellular mobile networks, or via satellite.
Typically, “clients” are applications that run on workstations and rely on mainframe/servers to perform certain operations. For example, an e-mail client is an application that enables a workstation to send and receive e-mail via a local area network (LAN) server and an e-mail server. The term “server” is thus used herein to denote a linked computing device or group of such devices acting as a single unit to provide centralized services to one or more workstations. Clients may rely on servers for any number of functions, including interconnection with other devices, web access, resources (such as database storage of files), and, in some cases, processing power. Web servers respond to a web browser's request by transmitting a web page, or other types of web content. Web content, as used herein, is a set of executable instructions a server serves to a client and which is intended to be executed by the client so as to provide the client with certain functionality.
In order to ensure proper routing of messages between networked devices, messages are first broken up into data packets, each of which receives a destination address according to a consistent protocol, and which are reassembled upon receipt by the target computer. Commonly accepted protocols for use over the Internet are Internet Protocol (IP), which dictates routing information, and Transmission Control Protocol (TCP), according to which messages are broken up into IP packets for transmission, collection, and reassembly.
Given the advances in network technology, a demand for software and systems capable of taking full advantage of these advancements is growing. In this regard, many organizations dependent on information technology are presently attempting to manage complex network environments (e.g., distributed environments) that incorporate diverse hardware, software, applications, networks, and database systems. For example, the microprocessors of devices in a distributed environment may be totally dissimilar from each other. Also, device components of distributed environments often run entirely different operating systems and are entirely independent of each other but strive to cooperate in the sharing of data. The communications protocols used by such distributed environments thus tend to be industry standards, such as Systems Network Architecture™ (“SNA”) and TCP/IP. Still, modes of cooperation between networked devices are far from optimal.
Thus, there has been an increasing demand for software and systems capable of fully integrating and optimizing use of these disparate components. Moreover, it would be desirable for these integrated systems, documents, and software to be hardware independent, support multiple users, and be based on a distributed architecture.
One particular situation where hardware independence would be desirable is printing via device drivers. A conventional, but inefficient, method of controlling and managing the flow of data to and from diverse input/output (I/O) devices in a distributed environment is through the use of device drivers. Device drivers are software programs that act as an interface between the device and programs that use the device. Generally, each device, such as a particular printer, has a set of specialized commands translatable by a driver for that device. In contrast, most programs access devices by using generic commands. The driver, therefore, accepts generic commands from a program and then translates them into specialized commands for the device.
Universal device drivers have been created in an effort to eliminate or reduce the numerous differing device drivers required by various operating systems in running various peripheral devices. Generally, universal drivers incorporate most of the code necessary for devices in a particular class of devices (such as printers or modems) to communicate with the appropriate operating system components (such as the printer or communications subsystems). Most often, universal drivers are used in combination with mini-drivers, which contain any additional instructions needed to operate a specific device.
However, universal device drivers often lack true platform independence in that the OS specific device drivers are programmed for preexisting, but not newer, peripherals. Additionally, while the device driver core is operating system independent, the OS specific device drivers are not. Thus, the OS specific device drivers often have to be replaced in order to conform to a newly installed operating system. Also, often, the operating system independent driver still must include information regarding peripheral device operation and peripheral specific data object. Thus, universal drivers do not completely solve the problems of software application and platform independence in the operation of networked peripherals.
A second area in which the resources of a distributed environment are not efficiently utilized is in the realm of web-based image retrieval, manipulation, and utilization. Presently, systems and services exist which allow web users to extract and share various imaging information over the Internet.
On-line information systems typically include one computer system (the server) that makes information available so that other computer systems (the clients) can access the information. The server manages access to the information, which can be structured as a set of independent on-line services. The server and client communicate via messages conforming to a communication protocol and sent over a communication channel such as a computer network or through a dial-up connection. Typical uses for on-line services include document viewing, electronic commerce, directory lookup, on-line classified advertisements, reference services, electronic bulletin boards, document retrieval, electronic publishing, keyword searching of documents, technical support for products, and directories of on-line services, among others. The service may make the information available free of charge, or for a fee, and may be on publicly accessible or private computer systems.
The user of an on-line service uses a program on the client system to access the information managed by the on-line service. Possible user capabilities include viewing, searching, downloading, printing, and filing the information managed by the server.
U.S. Pat. No. 5,870,552 to Dozier, et al. (“Dozier”), teaches a development platform technology for publishing hypermedia documents across wide area networks (WAN). Generally, Dozier addresses the problem of editing hypermedia documents on WAN servers for WAN publishing. Dozier notes that it is not generally possible to “open” multiple WAN documents for editing and to transfer text, images, and URL's among those documents in the seamless fashion as is presently done with typical word processors for local computer documents. Also, Dozier notes that current web authoring tools generally do not provide full WYSIWYG (“What You See Is What You Get”) feedback as to HTML markups and hypermedia links. However, Dozier does not teach a method to effectuate sharing of a device/software independent image in a mainframe printing environment.
U.S. Pat. No. 5,793,966 to Amstein et al. (“Amstein”) also teaches a client/server system, using a web server that allows for the creation and maintenance of an on-line service using a client system that remotely causes the server to perform operations required in the authoring process. However, Amstein does not address sharing a device/software independent image in a mainframe printing environment.
U.S. Pat. No. 5,987,480 to Donohue et al. teaches a system and method for delivering documents having dynamic content embedded over the worldwide Internet or a local internet or intranet. More specifically, customized HTTP content is provided based on the identity of the user operating the client computer so that the document is individualized to the user's interests and needs. Donahue does not teach editing, retrieval, and output of a device/software independent image in a mainframe printing environment.
Accordingly, there is a great need for a new development platform for distributed publishing that overcomes the various limitations described above. This need is especially pronounced and important in view of the rapid expansion of interest in the Internet.
Accessing web-based information in a mainframe operating system such as multiple virtual storage (“MVS”) and OS400 systems requires mainframe protocol such as system network architecture to communicate with one current internet protocol, TCP/IP. IBM mainframes running either MVS or VM can run software called TCP/IP for MVS and TCP/IP for VM. These products provide access from other machines running TCP/IP to access the mainframe operating system remotely, usually over a LAN. The software enables the client in a client/server scheme to act as a 3270-series terminal to MVS or VM. File Transfer Protocol (“FTP”) is provided for file transfers. Both TCP/IP software products support SMTP for electronic mail. Enabling TCP/IP protocol across a mainframe computer system may allow for Internet access for terminals connected to the mainframe. The mainframe, software, or other hardware as known in the art may assign IP addresses.
An interconnect controller, which sits between the mainframe and a network may be used to route communications for large systems. The interconnect controller handles high-speed traffic between a mainframe channel and the network to relieve mainframe processing of communications.
Likewise, printing in a mainframe environment is largely controlled by the mainframe. Print jobs are processed by the mainframe computer (acting as the print server) and may be distributed to printers via proprietary high-speed interfaces such as an IBM 370 Channel interface (commonly called “bus and tag”). Otherwise, conventional RS232C interfaces or other communication interfaces may be used. The printer may receive communications from the mainframe by way of a network interface card (“NIC”) or device attached to the printer.
The interface device attaches to the printer and interprets network communications sent in network protocol, such as SNA protocol, by IBM, then transmits page description language (“PDL”) commands that can be executed by the printer. For example, common PDLs include Postscript or PCL printer languages. Typically, in computer operating systems such as Windows™ or OS/2™, print drivers allow correct PDL generation for the desired printer from any program executed on the client. In addition, the interface device may provide information to the mainframe or server concerning printer characteristics or status via network protocol communications.
Alternatively, printing in a mainframe environment may also be accomplished via connection with another network, such as a Novell network that supports mainframe printing capabilities. One such network function is provided by Novell Distributed Printing Services (“NDPS”). NDPS combines conventional functions of a print queue, print server, and printer into one network object, the printer agent. A WAN connection may provide communication between the mainframe and server in the Novell network to accomplish printing. A print job that is sent to the mainframe by way of an application running on the mainframe, is redirected to a NetWare printing queue. Again, the print job is typically sent to a NIC residing in a network printer, which converts the network packets to PDL commands. Printer settings may be sent with the job and interpreted before executing the job, or default print queues with specific printer settings may be employed to fully define the printing operation. However, printing is still limited to the output devices installed and configured for network access.
Furthermore, in networked printing environments, serial communication and architecture is employed. For instance, one print queue is designated for each printer. Also, a specific print driver producing a specific PDL is necessary for printing. At least two significant limitations exist in network configurations with respect to imaging/printing: 1) printed images cannot be shared or manipulated easily; and 2) peripherals are limited to those connected to and configured for the network employed.
In addition, finished projects containing print jobs from different applications cannot be easily integrated prior to printing. Usually, each print job is generated by each application by way of the print driver and sent to a printer, or different printers. This method is inefficient and, furthermore, the disparate print jobs must be manually collated after printing. Although copy/paste functions of operating systems and applications somewhat alleviate this problem, it would be advantageous to assemble a single print job for printing from different applications by selecting files and previous print jobs to comprise the single print job.
Limitations and problems associated with print queues, print drivers, print job configuration and monitoring largely prevent mainframe users from gaining possible benefits of high functional access to peripherals and computing power of the Internet. In addition, hardware and software independence is desirable, because networks as well as the Internet may comprise diverse computer platforms and systems.
As illustrated by the prior art, it is desirable to provide mainframe printing clients with utmost functionality concerning peripherals, computing power, and imaging power available in a networked computing environment. Therefore, it would be of current interest to provide apparatus and methods for sharing imaging information between web-based services and devices in a distributed environment. More specifically, the present invention relates to apparatus and methods for sharing imaging information between web-based services and devices for users of mainframe printing environments. | {
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Method and device for the homogeneous heating of glass and/or glass-ceramic articles using infrared radiation.
The invention relates to a process for the homogeneous heating of semi-transparent and/or transparent glass articles and/or of glass-ceramic articles with the aid of infrared radiation, whereby the glass articles and/or the glass-ceramic articles undergo a heat treatment in the range from 20° C. to 3000° C., as well as to a device for the homogeneous heating of translucent and/or transparent glass articles and/or glass-ceramic.
Semi-transparent or transparent glass and/or glass-ceramics, for the setting-in of certain material properties, for example ceramization, are heated mostly to temperatures which lie preferably over the lower cooling point (viscosity Z=1014.5 dPas). In form-giving processes, especially hot after-processing, the semi-transparent or transparent glass and/or the glass-ceramic material is heated up to the processing point (viscosity Z=104 dPas) or beyond that. Typical lower cooling points can amount, depending on the type of glass, to between 282° C. and 790° C., and typically the processing point can be up to 1705° C.
Hitherto according to the state of the art semi-transparent or transparent glasses and/or glass-ceramics, for example for ceramization, were heated preferably with surface heating. As surface heating there are designated processes in which at least 50% of the total heat output of the heat source is introduced into the surface or surface-near layers of the object to be heated.
If the radiation source is black or gray and if it has a color temperature of 1500 K, then the source radiates off 51% of the total radiation output in a wavelength range above 2.7 μm. If the color temperature is less than 1500 K, as in most electric resistance heating elements, then substantially more than 51% of the radiation output is given off above 2.7 μm.
Since most glasses in this wavelength range have an absorption edge, 50% or more of the radiation output is absorbed by the surface or in surface-near layers. It is possible, therefore, to speak of surface heating. Another possibility lies in heating glass and glass-ceramics with a gas flame, in which typical flame temperatures lie at 1000° C. Such a heating occurs mainly by direct transfer of the thermal energy of the hot gas onto the surface of the glass or of the glass-ceramic, so that here it is possible to proceed from a predominantly surface/superficial/heating.
In general with the earlier described surface heating the surface or surface-near layers are heated in the parts of the glass or of the glass-ceramic that lie opposite the heating source. The remaining glass volume or glass-ceramic volume must accordingly be heated up correspondingly by heat conduction within the glass or the glass-ceramic material.
Since glass or glass-ceramic material has as a rule a very low heat conductivity in the range of 1 W (m K), glass or glass-ceramic material must be heated up more and more slowly in order to keep tensions in the glass or glass-ceramics low.
A further disadvantage of known systems is that, in order to achieve a homogeneous heating-up of the surface, the surface of the glass or of the glass-ceramic material must be covered as completely as possible with heating elements. Limits are placed there on conventional heating processes. With electrical heating resistances made of Kanthal wire, as they are preferably used, at 1000° C., for example, only a wall load of maximally 60 kW/m2 is possible, while a full-surfaced (or holohedral) black radiator of the same temperature could irradiate an output density of 149 kW/m2.
With a denser packing of the heating elements to be equated with a higher wall load, these would heat themselves up reciprocally, which through the resulting heat accumulation would involve an extreme shortening of the useful life of the heating elements.
When a homogeneous heating-up of the glass or of the glass-ceramic is not achieved or is only inadequately successful, then this unfailingly results in inhomogeneities in the process and/or in the product quality. For example, any irregularity in the process conducting, in the ceramization process of glass-ceramics leads to a cambering or bursting of the glass-ceramic article.
From DE 42 02 944 C2 there has become known a process and a device comprising IR radiators for the rapid heating of materials which have a high absorption above 2500 nm. In order to rapidly introduce, into the material, the heat given off from the IR radiators, DE 42 02 944 C2 proposes the use of a radiation converter from which secondary radiation is emitted with a wavelength range which is shifted into the long-wave direction with respect to the primary radiation.
A heating of transparent glass homogeneous in depth with use of short-wave IR radiators is described in U.S. Pat. No. 3,620,706. The process according to U.S. Pat. No. 3,620,706 is based on the principle that the absorption length of the radiation used in glass is very much greater than the dimensions of the glass object to be heated, so that the major part of the impinging radiation is let through by the glass and the absorbed energy per volume is nearly equal at every point of the glass body. What is disadvantageous in this process, however, is that no homogeneous irradiation over the surface of the glass objects is ensured, so that the intensity distribution of the IR radiation source is depicted on the glass to be heated. Moreover, in this process only a small part of the electric energy used is utilized for the heating of the glass.
The problem of the invention, therefore, is to give a process and a device for the homogeneous heating-up of semi-transparent or transparent glass and glass-ceramic articles, with which the aforementioned disadvantages are overcome. | {
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In chemical process operations, there are various instances in which it is desired to mix fluids at different temperatures, typically a vapor at the higher temperature with a liquid at the lower temperature, whereby the liquid is vaporized by contact with the hot vapor. Particularly where the liquid, when in liquid form, is highly corrosive to the surrounding environment, such as to vessel walls, valves, and the like, it is desirable to vaporize the liquid as quickly as possible and to reduce or minimize condensation that could cause corrosion of the equipment. One important application of these principles is in connection with the in-situ stabilization and/or regeneration of catalyst used in dehydrogenation processes.
For example, as described in U.S. Pat. Nos. 5,461,179; 5,686,369; 5,695,724 and 5,739,071, adding an alkali metal to the feed of a catalytic dehydrogenation reaction system can regenerate and/or stabilize the activity of the catalyst. A prime application of the basic process concept in the above patents is for the dehydrogenation of ethylbenzene to styrene in the presence of steam over a potassium promoted iron oxide catalyst. In this case, potassium is added to a reactor feed stream to improve both the conversion of ethylbenzene and the selectivity to styrene, as is described in the examples given in these patents. This potassium can be introduced either as potassium metal or a potassium compound such as potassium hydroxide (KOH). If metal is used, it can be introduced into the reactor feed as a solid, liquid (melting point 64° C.), or a vapor (normal boiling point 774° C.) and, when the potassium metal contacts the steam in the reactor feed, it converts to potassium hydroxide. If potassium hydroxide is used, it can be introduced as a solid, liquid (melting point 406° C.), or as an aqueous solution. No matter what the source of potassium, however, the potassium should be vaporized completely and mixed thoroughly with the reactor feed prior to the feed reaching the catalyst in the reactor for improved or optimum results.
Potassium metal is highly reactive; and thus, for safety reasons, potassium hydroxide will in many cases be preferred over potassium metal as the source of potassium in a commercial catalyst stabilization operation Compared with using solid or melted potassium hydroxide, aqueous potassium hydroxide solutions will in many cases be preferred because of the ease of handling an aqueous liquid at ambient temperatures.
One difficulty with using potassium hydroxide, however, is that it can be very corrosive, especially at elevated temperatures, either as an aqueous solution or as melted potassium hydroxide. Once the potassium hydroxide is fully vaporized and stays in the vapor phase, corrosion is typically much less of a problem If an aqueous solution is injected directly into the main process piping, then corrosion of the main process piping and equipment is possible. The KOH solution will contact the vessel walls because the short distances between solution injection point and the pipe walls typically will not allow adequate vaporization time before the potassium hydroxide, as solution, solid or liquid salt, reaches the walls. Furthermore, if the injection system is directly part of the main process piping, then the dehydrogenation process must be shut down if maintenance is required for the injection nozzle assembly.
To avoid damage and downtime for the dehydrogenation process unit, which is often a large and expensive process unit, we have found in accordance with this invention that it is advantageous to take at least a part of the steam being fed to the dehydrogenation process, vaporize the potassium hydroxide into it, and then mix this potassium-rich steam with the rest of the reactor feed. To vaporize the KOH solution, the potassium hydroxide solution can be sprayed into the steam portion inside a small, dedicated “mixing vessel,” which can be shut down for periodic maintenance without shutting down the entire dehydrogenation process. If the mixing vessel and spray nozzle assembly are designed properly, the KOH solution droplets can be vaporized before the droplets reach the walls of the vessel or the vessel outlet pipe, thereby, at least in theory, reducing or minimizing corrosion caused by unvaporized solution However, in our experience of utilizing such systems, we have found that this approach is insufficient by itself to avoid significant corrosion of the mixing equipment.
Part of the problem of using potassium hydroxide in such applications is that its vapor pressure is low even at the high dehydrogenation reaction temperatures. At 598° C., which is the reactor inlet temperature of Example 1 in previously mentioned U.S. Pat. No. 5,461,179, for example, the vapor pressure of potassium hydroxide is only 10 pascals. If the total pressure is 100 kilopascals at this temperature, then the concentration of potassium hydroxide in the vapor phase cannot exceed 100 parts per million on a molar basis even at this high temperature. At 514° C., the saturation concentration would be only 10 parts per million on a molar basis. Thus, the potassium must be diluted by relatively large amounts of high-temperature steam to get the potassium totally into the vapor phase.
Even if the average conditions of the steam fed to the mixing vessel are adequate to vaporize the aqueous potassium hydroxide solution, however, we have found that the potassium hydroxide vapor can re-condense if the interior surface temperature of the mixing vessel walls is below the dew point of potassium hydroxide. Such condensation on the mixing vessel walls can cause severe corrosion because of the highly corrosive nature of liquid potassium hydroxide at the high temperatures needed for vaporization.
Although it might be expected that the temperature of the walls in such a mixing vessel would be nearly the same as that of the vapor passing through the interior, we have found that the wall temperature can be surprisingly colder than the average steam temperature. We attribute this to the following technical factors: 1) heat loss to the environment through the walls, even with a thick layer of external insulation, can be substantial; 2) heat loss is almost always even higher at vessel nozzles and supports and 3) heat transfer from the steam to the walls can be poor because of the low steam velocity resulting from the vessel volume and geometry needed for complete vaporization of the KOH solution without impinging droplets on the walls. We have determined that the differential temperature between the vapor in the interior of the mixing vessel and the wall of the vessel can be in the range of 50 to 100° C. for conventionally-designed vessels insulated according to industrial standards for energy conservation.
In practice, parts of the mixing vessel walls can be significantly colder than this at vessel support points and at vessel nozzles where heat loss can be greater and/or heat transfer from the process steam can be slower. For example, the temperature of a manway lid in such a vessel can be substantially colder than the walls of the main part of the vessel because there is no flow past the manway lid due to the fact that it is in a cul-de-sac. In contrast, the wall temperatures of regular cylindrical pipes usually will be close to the temperature of the contained fluid flow because the economic sizing of pipes typically results in significant fluid velocities, which result in good heat transfer and thus low temperature differences between the contained flow and the pipe wall.
We explored a number of possible approaches to try to solve this problem of condensation due to “cold” vessel walls using commercially available equipment and by adapting conventional technologies. As discussed below, none of these approaches proved to be entirely satisfactory.
First, we considered increasing the steam flow, which decreases the dew-point temperature of the potassium hydroxide vapor by diluting it and decreases the temperature drop somewhat of the steam through the system due to heat loss if the heat loss does not increase proportionally more than the increase in the steam flow. However, we determined that increasing the steam flow results in a proportionally larger mixing vessel so as to maintain the vessel residence time needed for droplet vaporization; heating costs for the overall process increase because heat losses are increased with the larger mixing vessel and larger diameters of the associated piping; and, even beyond the cost of making up for additional heat loss, the cost of heating for the overall process is larger because the efficiency of heating this small steam flow for the mixing vessel typically will be lower than for the dehydrogenation process. Thus, increasing the steam flow enough to make a significant difference in corrosion protection substantially increases both the capital and operating costs.
A second approach we considered was that perhaps the mixing vessel could be insulated more effectively to lower the heat loss and, thus, increase the vessel wall temperature. However, we determined that increasing insulation thickness results in diminishing returns; and, at high temperatures, heat loss still can be substantial even with thick layers of insulation. Also, heavily insulated nozzles and manways on vessels at high temperatures can be problematic because if the nozzle flange bolts are under the insulation and kept very hot (above about 565° C. for stainless steels) they become loose because of high temperature “creep” whereby the bolt metal permanently stretches because of the combination of tension imposed from tightening and temperature. Once they stretch, the bolts do not put sufficient force on the flanges to the vessel sealed. Therefore, there is an incentive to not heavily insulate the flanges, but this practice leads to high, localized heat losses and, thus, cold spots on the mixing vessel wall where condensation can occur.
A third approach we considered was to add electric heaters or electric tracing to the outside of the mixing vessel underneath the insulation. At temperatures above about 550° C., however, this approach leads to high cost with the technologies available. Furthermore, because heat loss is not uniform from the mixing vessel because of nozzles, vessel supports and insulation imperfections, control of the electric heaters would be complicated. The metal temperatures must be high enough at all points exposed to the potassium hydroxide vapor so as to avoid condensation, but care must be taken to avoid overheating the mixing vessel walls, which can lead to unacceptably low metal strength. Also, as discussed above, the bolts on the nozzle flanges on very hot equipment preferably should not be as hot as the vessel contents to prevent leakage due to high temperature creep. This approach therefore would result in either the nozzles being “cold” spots for condensation and corrosion or, alternatively, locations for increased risk of leakage, depending on whether or not the electric heaters apply heat in the area of the nozzle flanges.
A fourth approach we considered was to install an external jacket on the mixing vessel such that a hot utility stream could be passed through the jacket to warm the vessel. However, such a jacket would need to be designed for the high temperatures and the pressure of the utility fluid. It would be difficult or even impractical to adequately jacket nozzles including manways, even if this is considered to be desirable given the potential sealing problems at high bolt temperatures. Furthermore, for such systems as described above, the temperatures required exceed the highest condensing temperature for steam and the maximum operating temperatures for commercially available organic heat transfer fluids. Thus, the heat transfer fluid in an external jacket system most likely would need to be a molten salt or liquid metal, which are difficult to use, and this results in very high operating and capital costs.
A fifth approach we considered was that the steam supply temperature to the mixing vessel could be increased, which increases all of the mixing vessel temperatures and increases the difference between the mixture temperature and the dew point of the potassium hydroxide. However, there are metallurgical limits to how high the temperature can be. For temperatures up to 815° C. (1500° F.), various 300-series stainless steels can be used to construct pressure-containing vessels and pipes. At higher temperatures, however, more expensive metals must be used, and maintenance costs increase. In general, though, increasing the operating temperature up close to the limit of metallurgy is a reasonable approach to reducing or minimizing the necessary flow rate of the dilution steam.
A sixth approach we considered was that the mixing vessel wall metal could be upgraded to an alloy able to withstand, if possible, the corrosion caused by condensing potassium hydroxide. Because of the highly aggressive nature of potassium hydroxide at these high temperatures, however, the metal costs can become prohibitively expensive, which results in a large increase in capital cost for the mixing vessel. Furthermore, if the potassium hydroxide is allowed to condense, it will accumulate in the vessel, require periodic removal, and will not be fed to the reaction system as desired.
These and other deficiencies in or limitations of the prior art and the varied considered adaptations of more conventional technologies to try to address the condensation problem are overcome in whole or in part by the improved methods for condensation reduction of this invention and the related mixing vessel design | {
"pile_set_name": "USPTO Backgrounds"
} |
The maximum cost benefit factor that can be derived from an automatic toll paying system is achieved when the system is universally applicable. Toll facilities differ in means of collection and in base rates, the rates often depending on the number of vehicle axles as well as distance traveled. A convenient system would have a motorist pay a lump sum of any amount to any toll authority, and be credited for that amount against future tolls. Any automatic toll paying method must have a relatively simple and efficient means of transferring funds, with appropriate checks and balances. The system must be relatively tamper-proof, fool-proof, enforceable and must operate through snow, ice, rain, fog, dirt and for any expected speed of the vehicle. A properly implemented system would also reduce toll facility operating expenses, save the driver time and fuel, and generate less air pollution for the toll facilities' neighbors.
Present methods aimed at implementing such a service employ only automatic vehicle identification. Such methods require intricate centralized computer facilities for storing and extracting billing information from potentially tens of millions of possible users for each toll transaction. These methods lack flexibility and user connection. They also can create massive operational failures and a feeling on the part of users of being dependent on large, complex and silent computers. | {
"pile_set_name": "USPTO Backgrounds"
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1. Field of the Invention
The invention relates in general to lamp harps and, more particularly, embodiments of the present invention relate to lamp harps wherein an inverted U-shaped bracket-headed machine screw assembly is mounted to the top of the harp frame for rotation through a limited arc so as to prevent a lamp shade from contacting a bulb mounted in an associated lamp socket.
2. Description of the Prior Art
Lamp harps have been well known for many years. Many lamp harps provide for the mounting of a lamp shade that is mounted through an assembly to the harp frame at the top of the harp. See, for example, Auerbach U.S. Pat. No. 1,946,959 (an upwardly extending threaded stud is fixed to the top of the harp so the angle of the shade is not adjustable); Berger U.S. Pat. No. 2,435,954 (an inverted U-shaped bracket-threaded stud assembly is rotatably mounted to a straight portion of the harp frame at the top of the frame so that the lamp shade can be tilted through whatever arc can be traversed until the shade encounters an obstacle—such as a light bulb—that prevents further rotation); and Schwartz et al. U.S. Pat. No. 2,481,355 (similar to Berger U.S. Pat. No. 2,435,954 showing an inverted U-shaped bracket-headed machine screw assembly). The uncontrolled rotation of the shade mounting assemblies of, for example, Berger and Schwartz et al. presents a fire safety hazard. When a combustible shade comes into contact with or close proximity to a hot bulb there is a risk of fire. Various elaborate rotational mechanisms had been previously proposed without addressing the fire safety issue. See, for example, Fanshier U.S. Pat. No. 3,309,515 (an elaborate and expensive machined clamp that is activated by a threaded lock purports to clamp the shade in a particular position); Truax et al. U.S. Pat. No. 3,281,590 (the shade is mounted through an elaborate and expensive ball-socket assembly); and Benander U.S. Pat. No. 2,670,432 (a multi-part shade mounting that apparently permits rotation around two perpendicular axes). Various complicated and expensive expedients had been previously proposed for limiting the rotation of a shade. See, for example, Jacobson U.S. Pat. No. 4,414,618 (an elaborate and expensive leveling plate mounted on top of a conventional inverted U-shaped bracket-threaded stud assembly); and Goldfine U.S. Pat. No. 3,016,455 (an elaborate and expensive lockable frusto-spherical bearing mounted on top of a conventional inverted U-shaped bracket-threaded stud assembly). Many other proposed expedients had been offered. Chilo U.S. Pat. No. 2,264,145, for example, discloses an expedient wherein the bulb is mounted in a downwardly depending configuration and the shade pivots with the bulb. The prior art devices and methods are not without their shortcomings. A major shortcoming of typical prior art devices and methods is that they are either too complicated and expensive to make or they present a fire hazard. Those concerned with these problems recognize the need for improvements.
These and other difficulties of the prior art have been overcome according to the present invention. | {
"pile_set_name": "USPTO Backgrounds"
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This invention relates to generating and accumulating status information associated with a data processing operation.
For example, in a vector operation (in which the same steps--e.g., add, multiply, accumulate--are performed on all data elements of the vector) it is useful to generate and accumulate the status (e.g., overflow, underflow, result) of each step to aid subsequent generation of exception conditions The status information typically is generated in a standard (e.g., IEEE 754) format.
Status information may be accumulated on a step by step basis and assembled as a status word (indicating the status of each step). In the case of a complex algorithm, e.g. for a vector operation, many steps are needed to produce a result, and the user typically does not need to know that a given step caused an overflow but only whether an overflow (or other exception) was generated somewhere among the steps that led to a particular result.
Sometimes status for a vector operation is generated by including, in the vector algorithm, microcode instructions to specify when status should be accumulated. | {
"pile_set_name": "USPTO Backgrounds"
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The present invention relates to a new and improved counting system having notable utility in registers of the type employed in fuel dispensing apparatus for registering the volume and cost amounts of fuel delivered and, for example, utility in the factory modification and/or field or factory conversion of existing fuel pump registers of the type shown and described in U.S. Pat. No. 2,814,444 of Harvey N. Bliss dated Nov. 26, 1957 and entitled "Register".
The conventional mechanical fuel pump register of the type shown and described in U.S. Pat. No. 2,814,444 has upper and lower resettable cost and volume counters on each of two opposite sides of the register for registering the cost and volume amounts of the fuel delivered. The register is conventionally employed with a mechanical variator (for example, of the type disclosed in U.S. Pat. No. 3,413,867 of Richard B. Hamlin dated Dec. 3, 1968 and entitled "Variator") operable for establishing and posting the desired unit volume price of fuel. The variator is connected for being driven by a fuel meter and for driving the volume and cost counters of the register for registering the volume amount of fuel delivered (e.g., in gallons) and the cost amount of fuel delivered in accordance with the volume amount of fuel delivered and the established unit volume price.
The mechanical cost counter drive train is rotated at a rate proportional to the established unit volume price and the volumetric rate of delivery and, therefore, for any given maximum volumetric rate of delivery, its maximum rate of rotation increases proportionally with the unit volume price of gasoline. Since the price of gasoline is escalating and is likely to continue to escalate, the cost counter drive train is and will continue to be rotated at correspondingly increasing rates. The resulting higher rotational speed decreases the life and increases the operating noise of the mechanical cost counter and its drive train. The higher rotational speed also increases the required drive torque transmitted from the meter through the variator to the cost counters and therefore decreases the useful life of the variator and the accuracy of the meter.
It is therefore a principal aim of the present invention to provide a new and improved counting system for a conventional fuel pump register for converting and/or modifying the register for increasing the useful life of the register and the reliability of its associated meter.
It is another aim of the present invention to provide new and improved register conversion means of the type described which permits conversion of existing mechanical registers with minimum inconvenience and downtime.
It is another aim of the present invention to provide a modified fuel pump register employing a new and improved cost counter drive system which substantially reduces the drive torque required for operating the cost counters and thereby substantially increases the operating life of the cost counters and the meter associated with the fuel pump register.
It is a further aim of the present invention to provide a new and improved gasoline pump register having an improved resettable cost counter.
It is another aim of the present invention to provide new and improved register conversion means useful in modifying the cost and/or volume section of conventional registers of the type described in the aforementioned U.S. Pat. No. 2,814,444.
It is a further aim of the present invention to provide a new and improved fuel pump register of the type described which is substantially the same size as existing fuel pump registers and such that the improved register can be readily substituted for an existing register and without further modification of the fuel pump.
It is another aim of the present invention to provide in a counting system of the type employing a bank of a plurality of coaxial counter wheels a new and improved wheel indexing system for indexing the bank of counter wheels.
It is a still further aim of the present invention to provide in a counting system of the type having an electrical pulse generator adapted to be driven for generating a pulse train with a pulse for each predetermined drive increment and a bank of a plurality of coaxial counter wheels of increasing order for displaying an accumulated count in accordance with the number of generated pulses, a new and improved counter wheel indexing system operable by the train of electrical pulses for indexing the bank of counter wheels for displaying an accumulated count in accordance with the number of generated pulses.
It is a further aim of the present invention to provide new and improved means for modifying the conventional fuel pump register for expanding the unit volume price range of its associated variator. In accordance with the present invention, the unit volume price of the conventional variator can be extended beyond the conventional maximum $0.99-9/10 unit volume price without requiring additional drive torque through the variator and without diminishing the operational life of the cost counter wheels of the associated fuel pump register.
It is another aim of the present invention to provide a new and improved cost counting system for a conventional fuel pump register for converting and/or modifying the register for extending the price range of the associated variator from the conventional price range of $0.000 to $0.999 per gallon to an expanded price range of $0.00 to $9.99 per gallon.
It is a further aim of the present invention to provide a new and improved cost counting system for a conventional fuel pump register which employs conventional cost counter wheels mechanically resettable in a conventional manner and which employs a new and improved cost counter wheel drive system which provides for substantially reducing the required cost counter drive torque and increasing the useful life of the cost counter wheels and their drive train.
It is another aim of the present invention to provide a new and improved counter indexing system for a resettable fuel pump register for automatically removing any initial counter readout error which occurs when the register is reset.
It is a further aim of the present invention to provide a new and improved counting system for a conventional fuel pump register useful in fuel pump installations, such as self-service installations, having a remote readout of the amount of fuel delivered, and which provides a remote readout which correctly corresponds to the register readout at the fuel delivery pump.
It is a further aim of the present invention to provide in a counting system of the type having a bank of a plurality of coaxial counter wheels of increasing order of significance, a new and improved wheel indexing system for indexing the bank of counter wheels for registering a count. Also, in accordance with one embodiment of the present invention, the wheel indexing system provides a one-hundred increment lowest order wheel, for example, for registering a count from 0 to 99, and a new and improved indexing system for indexing the second order counter wheel therewith in a manner avoiding any readout ambiguity during count transfers from the lowest to the second order counter wheels.
Other objects will be in part obvious and in part pointed out more in detail hereinafter.
A better understanding of the invention will be obtained from the following detailed description and the accompanying drawings of an illustrative application of the invention. | {
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The current practice of determining transducer position in magnetic storage devices during accessing and following data tracks on a rotating medium such as a disk is through amplitude measurement of signals from adjoining servo tracks thereby generating a net signal indicative of the radial displacement from a predetermined track centerline. As track densities have increased, the capability of this practice has been enlarged by progressing from dibit to tribit to pentabit servo formats thereby increasing the number of tracks in the capture area, and enabling a more precise track identification.
One of the problems with the current practices has been the susceptibility to inaccuracy as a result of random electrical noise occurring during the servo signal window. To mitigate this disability, the servo format has, in the past, used redundant signals which are averaged to obtain a more uniform approximation. | {
"pile_set_name": "USPTO Backgrounds"
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For institutional and industrial environments, wall plates for electrical outlets must withstand abuse to eliminate costly replacement. Standard electrical wall plates are unsuitable. The prior art comprises standard electrical wall plates and various wall plates with covers and safety devices used to prevent access. These include, for example, U.S. Pat. No. 5,907,126; U.S. Pat. No. 4,640,564; and U.S. Pat. No. 4,671,587.
Although these devices fulfill their restrictive and particular objectives and requirements, a standard electrical wall plate, as well as specialized embodiments of the wall plate, neither discloses nor describes a novel one-piece wall plate for mounting on a wall or other planar surface. The inventive device includes exterior and interior surfaces forming a perimeter, which has an upstanding wall communicating with the exterior and interior surfaces. The external surface defines a central opening designed for receiving the electrical outlet. Both surfaces have parallel sidewalls or members that shape the device. Corners are formed by the meeting of the parallel members or sides. Apertures or bores are adjacent the corners for receiving inserts for securely holding the wall plate and outlet in place. Channels are placed through the exterior and interior surfaces to assist the insert passing through the wall plate to be securely fastened to a wall or planar surface.
In these respects, the oversized electrical outlet wall plate, according to the present invention, substantially departs from conventional concepts and designs in the prior art, and in so doing, provides a device allowing a design for institutional and industrial environments. Prior art device cover plates may be damaged by abuse. The impact-resistant, one-piece design of the present invention does not rust or break, and therefore, withstands abuse. The large size of the wall plate provides for increased security and safety and allows it to be securely fastened to a wall or other planar surface. | {
"pile_set_name": "USPTO Backgrounds"
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This invention relates to the fabrication of a DRAM cell consisting of a MOS transistor and a capacitor which is stacked over the transistor, and more particularly to a method of producing a cylindrical storage node of the stacked capacitor.
In MOS DRAMs, since the introduction of the 1k DRAM in the early 1970s the memory density has been multiplied by 4 every 3 years with a reduction in memory cell area to 30-40%. Although the memory cell area is reduced, it is necessary to retain a sufficiently large storage capacitance in order to keep immunity to soft errors. In this regard, it is advantageous to employ stacked capacitor cells.
For further enhancement of the density of DRAM cells with furhter reduction in memory cell area, a stacked capacitor cell having a cylindrical capacitor is under development. The storage node of the cylindrical capacitor has a hollow cylinder of polysilicon (polycrystalline silicon) which stands vertically, and both the outer and inner surfaces of the cylinder are used as a capacitance area. With this structure the storage capacitance can be increased without enlarging the memory cell area.
For example, JP-A 2-260454 (1990) shows a method of producing the above-mentioned cylindrical capacitor.
In the accompanying drawings, FIG. 4 shows the structure of a memory cell produced by using a method according to JP-A 2-260454. On a p-type silicon substrate 60, a field oxide film 62 defines an active area. The memory cell has a MOS transistor 64 with a gate oxide film 66 and n.sup.+ -type source and drain regions 70, 72 in the substrate 60 and a gate electrode 68 on the substrate. Dielectric films 74 and 76 constitute an interlayer insulator. Bit line interconnection 82 on the interlayer insulator is connected to the source/drain region 70 of the transistor by a contact 80 provided by using a contact hole 78 in the insulator. The interconnection 82 is covered by a silicon oxide film 84, which is overlaid with a planarizing film 86 of borophosphosilicate glass (BPSG), viz. silicon oxide doped with boron and phosphorus. On the planarizing film 86 there is another silicon oxide film 88 which is used as an etch stop film. The films 84, 86 and 88 constitute a second interlayer insulator. A cylindrical capacitor 94 stands on the silicon oxide film 88. The capacitor consists of a cylindrical storage node (viz. a lower plate) 96 having a closed bottom, a dielectric film 98 which covers the outer and inner surfaces of the storage node 96 and a conductor film (upper plate) 100 deposited on the dielectric film 98. The bottom of the storage node 96 is connected to one of the source/drain regions 70, 72 of the transistor by a contact 92 which is provided by using a contact hole 90 in the interlayer insulators.
FIGS. 5(A) to 5(F) illustrate a known process of forming the cylindrical storage node 96 in FIG. 4.
Referring to FIG. 5(A), the surface of the BPSG film 86 is planarized by a reflow treatment, and the silicon oxide film 88 is deposited to a thickness sufficient for an etch stop film. Then the contact hole 90 for the storage node is formed by photolithography and etching.
Referring to FIG. 5(B), a conductor film (not shown) is deposited on the etch stop film 88 until the contact hole 90 is filled with the deposited conductor 92, and then the conductor film is removed by an etch-back treatment so as to leave the conductor 92 only in the contact hole 90. It is inevitable that the etch stop film 88 also undergoes etching and consequently) considerably reduces thickness.
Referring to FIG. 5(C), a polysilicon film 96A is deposited on the etch stop film 88, and a relatively thick BPSG film 102 is deposited on the polysilicon film 96A. Then, the BPSG film 102 and the underlying polysilicon film 96A are patterned into the shape of a solid cylinder by photolithography and etching. The BPSG film 102 in the cylindrical shape becomes a temporary core of the aimed cylindrical storage node.
Referring to FIG. 5(D), a polysilicon film 96B is deposited on the etch stop film 88 so as to entirely cover the BPSG core 102 and the underlying polysilicon film 96A.
Referring to FIG. 5(E), the polysilicon film 96B is subjected to etch-back by anisotropic etching so as to leave the film 96B only as a cylindrical sidewall on the side face of the BPSG core 102 and the underlying polysilicon film 96A. After that, as shown in FIG. 5(F), the BPSG core 102 is completely removed by selective etching with high selectivity to the BPSG core 102 relative to the etch stop film 88. The polysilicon film 96A lying on the etch stop film 88 and the cylindrical sidewall part of the polysilicon film 96B constitute the cylindrical storage node 96 shown in FIG. 4.
In the above process, the etch stop film 88 is repeatedly exposed to etching solutions or gases. Therefore, it is likely that the etch stop film 88 in FIG. 5(F) is unduly thin or has openings. Then, the etching solution penetrates into the BPSG film 86 and locally dissolves the film 86 to form some cavities 106. When cavities exist in the BPSG film 86, subsequent heat treatments will induce unexpected stress in the film 86, and the dielectric film of the capacitor may be damaged by the influence of the stress.
If the initial thickness of the etch stop film 88 is greatly increased to compensate for the inevitable loss of film thickness, it becomes difficult to form the contact hole 90 because etching is liable to terminate before reaching the substrate surface. Incompleteness of the contact hole 90 is a cause of an open contact defect of the storage capacitor and a resultant bit error.
When the etch stop film 88 is very thick, it is conceivable to omit the planarizing BPSG film 86 to avoid undesriable increase in the total thickness of interlayer insulators. However, in that case the etch stop film 88 has a stepped profile reflecting steps on the underlying layer. So, in the photolithography for forming the contact hole 90 a resist pattern is formed on an unplanarized surface, and therefore there is a possibility of inaccurate opening of the contact hole 90. For this reason, the storage node contact is likely to be defective. | {
"pile_set_name": "USPTO Backgrounds"
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In a standard motor-vehicle cooling system sensors are provided for determining the fill level of the liquid. Such sensors can be of the simple float or pressure type and serve mainly to ascertain if the fill level dips below a certain threshold. This information is used to indicate to the driver that the coolant supply should be checked.
Such a system is invariably of the simple on/off type, that is it merely indicates whether or not the fill level is above or below a certain threshold. It gives no indication of how much above or below, that is does not provide an output of relative fill level. In addition the sensors of such systems are notoriously unreliable. Most work poorly in a sometimes violently moving bath of water containing various chemically active substances and have a short service life.
In another known system described in German patent document 41 16 496 a device detects overloading of the coolant pump and alters the timing or fuel feed of the engine so that it runs cooler. Thus this arrangement provides a sort of emergency operation mode, but in no way supplies the user of the engine with information about how much coolant is in the system. | {
"pile_set_name": "USPTO Backgrounds"
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Radio Frequency Identification (RFID) technology employs a radio frequency (“RF”) wireless link and ultra-small embedded computer circuitry. RFID technology allows physical objects to be identified and tracked via these wireless “tags”. It functions like a bar code that communicates to the reader automatically without requiring manual line-of-sight scanning or singulation of the objects. RFID promises to radically transform the retail, pharmaceutical, military, and transportation industries.
Several advantages of RFID technology are summarized in Table 1:
TABLE 1Identification without visual contactAble to read/writeAble to store information in tagInformation can be renewed anytimeUnique item identificationCan withstand harsh environmentReusableHigh Flexibility/Value
As shown in FIG. 1, a basic RFID system 100 includes a tag 102, a reader 104, and an optional server 106. The tag 102 includes an integrated circuit (IC) chip and an antenna. The IC chip includes a digital decoder needed to execute the computer commands the tag 102 receives from the tag reader 104. The IC chip also includes a power supply circuit to extract and regulate power from the RF reader; a detector to decode signals from the reader; a back-scattering modulator to send data back to the reader; anti-collision protocol circuits; and at least enough EEPROM memory to store its EPC code.
Communication begins with a reader 104 sending out signals to find the tag 102. When the radio wave hits the tag 102 and the tag 102 recognizes the reader's signal, the reader 104 decodes the data programmed into the tag 102. The information can then be passed to a server 106 for processing, storage, and/or propagation to another computing device. By tagging a variety of items, information about the nature and location of goods can be known instantly and automatically.
The system uses reflected or “backscattered” radio frequency (RF) waves to transmit information from the tag 102 to the reader 104. Since passive (Class-1 and Class-2) tags get all of their power from the reader signal, the tags are only powered when in the beam of the reader 104.
The Auto ID Center EPC-Compliant tag classes are set forth below:
Class-1 Identity tags (RF user programmable, maximum range ˜3 m)
Class-2 Memory tags (8 bits to 128 Mbits programmable at maximum ˜3 m range) Security & privacy protection
Class-3 Battery tags (256 bits to 64 Kb) Self-Powered Backscatter (internal clock, sensor interface support) ˜100 meter range
Class-4 Active tags Active transmission (permits tag-speaks-first operating modes) Up to 30,000 meter range
In RFID systems where passive receivers (i.e., Class-1 tags) are able to capture enough energy from the transmitted RF to power the device, no batteries are necessary. In systems where distance prevents powering a device in this manner, an alternative power source must be used. For these “alternate” systems (also known as active or semi-passive), batteries are the most common form of power. This greatly increases read range, and the reliability of tag reads, because the tag doesn't need power from the reader. Class-3 tags only need a 10 mV signal from the reader in comparison to the 500 mV that a Class-1 tag needs to operate. This 2,500:1 reduction in power requirement permits Class-3 tags to operate out to a distance of 100 meters or more compared with a Class-1 range of only about 3 meters.
Conventional RFID tags interact strongly with the electrical and magnetic fields near them; in fact most are resonant with Q-factors ranging between 5 and 100. Unfortunately, this also means that these tags also interact very strongly with each other in ways that often prevents the tags from being read at all. The problem becomes even worse when the tagged objects are thin and flat—like poker chips, currency, documents, etc. In such a stack, the energy received by each object/tag is highly non-uniform, with the outermost objects receiving most of the energy and the interior objects shielded by the outer objects and receiving virtually no energy at all. In other words, the antenna of the outer tag serves as a Faraday shield to anything behind it. The tags on the outside of the stack will continue to work well, but the tags on the inside of the stack work very poorly if at all. For these reasons conventional wisdom was that it impossible to read a stack of tagged items.
As touched on above, in addition to blocking RF energy, the antennae interfere with RF energy in their vicinities, potentially rendering the RF signal unreadable to tags nearby. This phenomenon is best understood by considering the radar profile of the antenna. The radar profile of the antenna may often be larger than the actual physical profile of the antenna, and can be a large as 100× the physical profile of the antenna. Accordingly, the problems mentioned above can also be found in assemblies of tagged objects that are not necessarily stacked.
There are many instances where tags could be stacked or assembled in close proximity. One implementation is in poker chips. Another is paper objects such as birth certificates, paper currency, etc. Significant tag-to-tag interactions and variability also occur even with a row of tagged objects sitting on a shelf. It would be desirable to read a stack of poker chips, stack of tagged currency, file of papers, etc. in one pass via RFID technology. | {
"pile_set_name": "USPTO Backgrounds"
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1. Field of the Invention
The present invention relates to a vehicle detection system.
2. Description of the Related Art
Conventionally, a vehicle detection system for detecting a state inside a vehicle that is changed by movement of a passenger in the vehicle may be mounted on the vehicle. For example, the vehicle detection system includes a detection device that detects the presence of a passenger seated on a seat of the vehicle (for example, Japanese Patent Application Laid-open No. 2004-189151).
In a conventional vehicle detection system, a detection device is connected to a battery via wiring, and power is supplied to the detection device from the battery. In this manner, the conventional vehicle detection system requires the battery that supplies power to the detection device and wirings to connect the battery with the detection device, a place to install the detection device is therefore limited. In this respect, there is still room for improvement in the conventional vehicle detection system. | {
"pile_set_name": "USPTO Backgrounds"
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The present inventors have recognized that typical in-counter and presentation-type data readers do not use solid state imaging devices, such as a charge-coupled device (CCD) imager or a complimentary metal-oxide-semiconductor (CMOS) imager to capture data. The present inventors have also recognized there are several challenges to including solid state imaging devices in in-counter and presentation-style data readers. One such challenge is locating a light source in the housing such that a read volume is adequately illuminated without reflecting light back onto the solid state imager. Another such challenge recognized by the present inventors is providing a light source including light emitting diodes (LEDs) that does not create harsh point source lighting effects, such as shining brightly in a user's eyes. Another such challenge is providing a light source including LEDs that lights a read volume relatively evenly and without creating specular reflection off an object in the read volume.
One device for using LEDs as a light source for a bar code reader includes a number of conical reflectors with an LED at the base of each cone as disclosed in U.S. Pat. No. 5,723,868. While rotationally symmetric reflectors, such as cylindrical reflective cones, are efficient at reflecting light emitted from each LED, the present inventors have recognized that such rotationally symmetric reflectors produce a circular appearance of light and do not blend the light from each LED together, thus creating brighter and darker areas in the illuminated area and an unpleasing appearance.
Accordingly, the present inventors recognized there is a need for an in-counter, presentation-style, or other suitable style, data reader with a solid state imager and a lighting system with lighting devices that provide adequate illumination for the solid state imager to capture high-quality images of objects in a read volume. The present inventors also recognized there is a need for a lighting system with improved lighting devices that (a) do not reflect light onto the solid state imager, (b) do not create harsh point source lighting effects, (c) lights a read volume relatively evenly, (d) does not create specular reflection off an object in the read volume, and (e) blends the light from multiple LEDs together to create illumination without substantially brighter and darker areas, singularly, or in any combination. | {
"pile_set_name": "USPTO Backgrounds"
} |
1. Field of the Invention
The present invention relates to an apparatus for correcting image distortions automatically by inter-image processing.
2. Description of the Prior Art
In the medical field, for example, a functional image of a certain physical region of the patient under examination is taken to make a diagnosis. The functional image is taken by measuring a same vital region of the patient at two different moments which indicate the correlation between the image of the two moments. The correlation is obtained by first taking the difference between the two images, and doing certain processing after that.
However, in case of a moving physical organ, the movement of the organ causes undesirable effects upon the desired functional information to impair the reliability of the real functional image. | {
"pile_set_name": "USPTO Backgrounds"
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The present disclosure relates to a method for producing a substantially single mode laser pulses and a laser for producing the same.
When a beam of light enters the eye, the beam passes through the cornea, lens, and the vitreous humor. The portion of the beam that is not absorbed is focused by the eye lens onto the retina. Under normal conditions, the light energy is converted by the retina into chemical energy, stimulating optical sensations. Laser beams with wavelengths longer than about 2.2 μm are strongly absorbed by the cornea and can cause damage to the cornea. Laser beams with wavelengths shorter than about 1.4 μm are not absorbed in the cornea or vitreous humor and therefore can cause damage to the retina. Laser beams having a wavelength in the range of 1.5 μm to 2.2 μm are not absorbed by the cornea, but are completely absorbed by the vitreous humor of the eye thereby alleviating any damage to the retina. Therefore, laser beams having a wavelength in the range of 1.5 μm to 2.2 μm are generally considered to be “eye-safe” lasers.
It is always desirable to have a powerful laser beam while still maintaining the quality of such laser beam. Beam quality is typically measured by how fast a laser beam grows in size as it propagates along, relative to that of an ideal beam. Examples of ideal beams are top hat and gaussian beams. An ideal top hat beam starts out with a uniform intensity across an aperture and a flat phase front. A gaussian beam has a bell-shaped intensity profile and a flat phase front. Another example of an ideal beam is the lowest-order mode of an optical fiber. A diffraction-limited laser beam is one that grows in size at a rate equal to that of an ideal beam.
Multi-mode fibers are optical fibers with a relatively large core area that can support multiple propagation modes. In contrast, a single-mode fiber has a substantially smaller core area and is able to support only one propagation mode. Typical core diameters for single-mode fibers are around 9 microns, whereas the core diameters of multi-mode fibers can reach hundreds of microns.
Q-switched pulses are energetic pulses produced by lasers by rapidly switching the Q factor (or quality factor) of a laser resonator from low to high. A high Q factor corresponds to low resonator losses per round trip, and a low Q factor to high round trip losses. This is normally accomplished using a variable attenuator inside the resonator cavity. In passively Q-switched lasers, the variable attenuator is a saturable absorber. A saturable absorber has a low transmittance (high loss) initially, but quickly increases its transmittance (low loss) when the intensity in the resonator cavity reaches a high enough level. Q-switched laser pulses can range from tens of picoseconds to hundreds of nanoseconds, with peak powers ranging from kilowatts to Gigawatts.
Microchip lasers do not employ pump guiding and are therefore limited to short cavity lengths to achieve sufficient coupling between diode pump and laser signal beams due to faster spreading (lower beam quality) of diode pump light. The short microchip cavity results in a correspondingly small lowest-order transverse laser mode diameter. Prior attempts to achieve a larger signal beam diameter in a microchip laser by increasing the pump beam diameter, resulted in the excitation of multiple signal transverse modes. This causes an increase in laser pulse width or multiple pulsing, and a degradation in signal beam quality. In eye-safe microchip lasers (i.e., microchip lasers having an eye-safe wavelength radiation), Erbium ion concentration is limited by up conversion effects, thus further limiting the achievable gain. For all these reasons, the output pulse energy of a sub-nanosecond microchip laser is typically only a few microjoules (at best). Generation of nanosecond eye-safe laser pulses with an optical parametric oscillator (OPO) is problematic. This is due to the fact that a long pump pulse is required for the signal beam to build-up from noise in the OPO cavity. In an OPO, the pump energy is stored in the electromagnetic field of the pump beam, and not in an excited state of a laser ion such as Erbium. This means the OPO signal beam will have a similarly long pulse width. An optical parametric amplifier (OPA) has been used to generate short 1.5 μm pulses but it requires a sub-nanosecond, high pulse energy pump laser and many passes through an OPA crystal. Typical conversion efficiency from pump to signal is only 25-30%. This OPA architecture is significantly larger and more complex than a microchip laser. Also, using this as a master oscillator (MO) seed for an Erbium-doped amplifier is difficult since its wavelength must be closely matched to that of the amplifier. Mode-locked Erbium lasers can also be used to generate sub-nanosecond pulses at 1.5 μm, but are extremely large and complex.
The present disclosure provides improvements over the prior art methods for producing a substantially single mode laser pulses. | {
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The present disclosure is generally related to systems and methods for smart packaging.
Devices such as cellular phones and phone calling cards can be bought at many retail locations. To use many of these devices, the device must be activated via a time consuming activation process. The activation process usually involves a user manually inputting a lengthy activation number or additional hardware such as a barcode scanner at the retail location specifically adapted for the activation process. Thus, the activation process at the retail location can be time consuming and expensive. The systems and methods described herein present solutions to at least these problems. | {
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Computer systems today are subject to a variety of attacks that can disrupt or disable normal operation of a computer system. Computer viruses, worms, and trojan horse programs are examples of different forms of attack. Attacks can also come directly from unscrupulous users of a computer system. Often these attacks take the form of attempts to modify existing program code executed by the computer system or attempts to inject new unauthorized program code at various stages of normal program execution within the computer system. Systems and methods for preventing such malicious attacks are becoming increasingly important.
A typical computer system comprises computer hardware, an operating system, and one or more application programs. The computer hardware typically comprises a processor (sometimes also referred to as a “central processing unit” or “CPU”), a memory, and one or more system buses that facilitate communication among the various components. Other components of a typical computer system include input/output controllers, a memory controller, a graphics processing unit, an audio controller, and a power supply.
Such systems generally have a small amount of on-chip memory (referred to as cache memory) and a much larger amount of off-chip memory (referred to as system memory). The off-chip memory in such systems is generally not considered to be trustworthy (cache memory may also not be considered trustworthy but can be much easier to protect through hardware mechanisms that prevent an attacker from reading the contents of cache memory). That is, data stored in the large system memory is vulnerable to attack wherein the data could be easily altered in a way that was not intended by the owners of the data. Such an attack would cause a program to operate in an unintended manner or allow copy protection scheme to be defeated.
A number of systems have been developed that try to ensure that the data retrieved from system memory can be secured. In particular, systems have employed extensive encryption techniques as well as other tamper evident mechanisms that detect alterations to data in memory.
The operating system can be thought of as an interface between the application programs and the underlying hardware of the computer system. The operating system typically comprises various software routines that execute on the computer system processor and that manage the physical components of the computer system and their use by various application programs.
The processor of a computer system often includes a memory management unit that manages the use of memory by the operating system and any application programs. Many of the attacks against computer systems target programs in memory. For example, portions of code that execute security checks could be defeated by simply replacing that portion of a program when it is stored in memory. Other attacks could modify computer games and change the behavior. For example, consider a situation in which a vulnerability is discovered in a multiplayer game that allows a player to gain an unfair advantage by changing the code on his local machine. Such an unfair advantage could undermine the popularity of an otherwise popular game. All of these considerations suggest that it is highly desirable to prevent unauthorized alterations to program code. | {
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1. Field of the Invention
The present invention relates to a carbon nanotube device using a carbon nanotube and a manufacturing method thereof. More particularly, the invention relates to a carbon nanotube device applicable to a functional device such as a quantum-effect device, an electronic device, a micro-machine device or a bio-device etc. Further, the invention relates to a carbon nanotube device applicable to an electron source, an STM (scanning type tunnel microscope) probe, or an ATM (atomic force microscope) probe by the utilization of sharpness of the carbon nanotube, and a manufacturing method thereof.
The invention relates also to an electron emitting device for a display, a cathode ray tube, an emitter, a lamp or an electronic gun.
2. Description of the Related Art
Fibrous carbon is generally called carbon fiber, and for carbon fiber that is used as a structural material having a diameter of at least several xcexcm, several manufacturing methods have been studied. Among those studied, a method for manufacturing the carbon fiber from a PAN (polyacrylonitrile)-based fiber or a pitch-based fiber is considered to be a mainstream method.
Schematically, this method comprises making a raw material spun from a PAN fiber, an isotropic pitch or a meso-phase pitch non-meltable and hardly flammable, carbonizing the resultant material at a temperature within a range of from 800 to 1,400xc2x0 C., and treating the resultant product at a high temperature within a range of from 1,500 to 3,000xc2x0 C. The carbon fiber thus obtained is excellent in mechanical properties such as strength and modulus of elasticity, and for its light weight that can be used for a sporting good, an adiabatic material and a structural material for space or automotive purposes in the form of a composite material.
On the other hand, a carbon nanotube has recently been discovered having a tubular structure whose diameter is 1 xcexcm or less. An ideal structure of the carbon nanotube is a tube formed with a sheet of carbon hexagonal meshes arranged in parallel with its tube axis. A plurality of such tubes forms a nanotube. The carbon nanotube is expected to have characteristics like metals or semiconductors, depending upon both diameter of the carbon nanotube and the bonding form of the carbon hexagonal mesh sheet. Therefore, the carbon nanotube is expected to be a functional material in the future.
Generally, carbon nanotubes are synthesized by the application of the arc discharge process, a laser evaporation process, a pyrolysis process and the use of plasma.
(Carbon Nanotube)
An outline of a recently developed carbon nanotube will now be described.
A material having a diameter of up to 1 xcexcm, smaller than that of carbon fiber, is popularly known as a carbon nanotube to discriminate from carbon fiber, although there is no definite boundary between them. In a narrower sense of the words, a material having the carbon hexagonal mesh sheet of carbon substantially in parallel with the axis is called a carbon nanotube, and one with amorphous carbon surrounding a carbon nanotube is also included within the category of carbon nanotube.
The carbon nanotube in the narrower definition is further classified into one with a single hexagonal mesh tube called a single-walled nanotube (abbreviated as xe2x80x9cSWNTxe2x80x9d), and one comprising a tube of a plurality of layers of hexagonal meshes called a multiwalled nanotube (abbreviated as xe2x80x9cMWNTxe2x80x9d).
Which of these types of carbon nanotube structures is available is determined to some extent by the method of synthesis and other conditions. It is however not as yet possible to produce carbon nanotubes of the same structure.
These structures of a carbon nanotube are briefly illustrated in FIGS. 1A to 4B. FIGS. 1A, 2A, 3A and 4A are schematic longitudinal sectional views of a carbon nanotube and carbon fiber, and FIGS. 1B, 2B, 3B and 4B are schematic sectional views illustrating transverse sections thereof.
The carbon fiber has a shape as shown in FIGS. 1A and 1B in which the diameter is large and a cylindrical mesh structure in parallel with its axis has not grown. In the gas-phase pyrolysis method using a catalyst, a tubular mesh structure is observed in parallel with the axis near the tube center as shown in FIGS. 2A and 2B, with carbon of irregular structures adhering to the surrounding portions in many cases.
Application of the arc discharge process or the like gives an MWNT in which a tubular mesh structure in parallel with its axis grows at the center as shown in FIGS. 3A and 3B, with a slight amount of amorphous carbon adhering to surrounding portions. The arc discharge process and the laser deposition process tend to give an SWNT in which a tubular mesh structure grows as shown in FIGS. 4A and 4B.
The following three processes are now popularly used for the manufacture of the aforementioned carbon nanotube: a process similar to the gas-phase growth process for carbon fiber, the arc discharge process and the laser evaporation process. Apart from these three processes, the plasma synthesizing process and the solid-phase reaction process are known.
These three representative processes will now be described:
(1) Pyrolysis Process Using Catalyst
This process is substantially identical with the carbon fiber gas-phase growth process. The process is described in C. E. Snyders et al., International Patent No. WO89/07163 (International Publication Number). The disclosed process comprises the steps of introducing ethylene or propane with hydrogen into a reactor, and simultaneously introducing super-fine metal particles. Apart from these raw material gases, a saturated hydrocarbon such as methane, ethane, propane, butane, hexane, or cyclohexane, and an unsaturated hydrocarbon such as ethylene, propylene, benzene or toluene, acetone, methanol or carbon monoxide, containing oxygen, may be used as a raw material.
The ratio of the raw material gas to hydrogen should preferably be within a range of from 1:20 to 20:1. A catalyst of Fe or a mixture of Fe and Mo, Cr, Ce or Mn is recommended, and a process of attaching such a catalyst onto fumed alumina is proposed.
The reactor should preferably be at a temperature within a range of from 550 to 850xc2x0 C. The gas flow rate should preferably be 100 sccm per inch diameter for hydrogen and about 200 sccm for the raw material gas containing carbon. A carbon tube is generated in a period of time within a range of from 30 minutes to an hour after introduction of fine particles.
The resultant carbon tube has a diameter of about 3.5 to 75 nm and a length of from 5 to even 1,000 times as long as the diameter. The carbon mesh structure is in parallel with the tube axis, with a slight amount of pyrolysis carbon adhering to the outside of the tube.
H. Dai et al. (Chemical Physico Letters 260, 1996, p. 471-475) report that, although at a low generating efficiency, an SWNT is generated by using Mo as a catalytic nucleus and carbon monoxide gas as a raw material gas, and causing a reaction at 1,200xc2x0 C.
(2) Arc Discharge Process
The arc discharge process was first discovered by Iijima, and details are described in Nature (vol. 354, 1991, p. 56-58). The arc discharge process is a simple process of carrying out DC arc discharge by the use of carbon rod electrodes in an argon atmosphere at 100 Torr. A carbon nanotube grows with carbon fine particles of 5 to 20 nm on a part of the surface of the negative electrode. This carbon tube has a diameter of from 4 to 30 nm and a length of about 1 xcexcm, and has a layered structure in which 2 to 50 tubular carbon meshes are laminated. The carbon mesh structure is spirally formed in parallel with the axis.
The pitch of the spiral differs for each tube and for each layer in the tube, and the inter-layer distance in the case of a multi-layer tube is 0.34 nm, which substantially agrees with the inter-layer distance of graphite. The leading end of the tube is closed by a carbon network.
T. W. Ebbesen et al. describe conditions for generating carbon nanotubes in a large quantity by the arc discharge process in Nature (vol. 358, 1992, p. 220-222). A carbon rod having a diameter of 9 mm is used as a cathode and a carbon rod having a diameter of 6 nm, as an anode. These electrodes are provided opposite to each other with a distance of 1 mm in between in a chamber. An arc discharge of about 18 V and 100 A is produced in a helium atmosphere at about 500 Torr.
At 500 Torr or under, the ratio of the carbon nanotubes is rather low, and at over 500 Torr, the quantity of generation decreases as a whole. At 500 Torr which is the optimum condition, the ratio of carbon nanotubes reaches 75%.
The collection ratio of carbon nanotubes is reduced by causing a change in supplied power or changing the atmosphere to argon one. More nanotubes are present near the center of the carbon rod.
(3) Laser Evaporation Process
The laser evaporation process was first reported by T. Guo et al. in Chemical Physics Letters (243, 1995, p. 49-54), and further, generation of a rope-shaped SWNT by the laser evaporation process is reported by A. Thess et al. in Science (vol. 273, 1996, p. 483-487).
First, a carbon rod formed by dispersing Co or Ni is placed in a quartz tube, and after filling the quartz tube with Ar at 500 Torr, the entire combination is heated to about 1,200xc2x0 C. Nd-YAG laser is condensed from the upstream end of the quartz tube to heat and evaporate the carbon rod. Carbon nanotubes are thus accumulated in the downstream end of the quartz tube. This process is hopeful for selective preparation of SWNTs, and has a feature that SWNTs tend to gather to form a rope shape.
The conventional art will now be described in terms of application of the carbon nanotube.
(Application of Carbon Nanotube)
While no applied product of carbon nanotube is available at present, active research efforts are being made for its applications. Typical examples of such efforts will be briefly described.
(1) Electron Emission Source
The carbon nanotube, having a shape leading end and being electrically conductive, is adopted in many research subjects.
W. A. De Heer et al. refined a carbon nanotube obtained by the application of the arc discharge process, and placed it upright on a support via a filter to use it as an electron source (Science, vol. 270, 1995, p. 1179). They report that the electron source comprised a collection of carbon nanotubes, and an emission current of at least 100 mA was stably obtained by the impression of 700 V from an area of 1 cm2.
A. G. Rinzler et al. evaluated properties by attaching an electrode to a carbon nanotube obtained by the arc discharge process, and there was available an emission current of about 1 nA from a carbon nanotube with a closed end, and of about 0.5 xcexcA from a carbon nanotube with an open end, by the impression of about 75 V (Science, vol. 269, 1995, p. 1550).
(2) STM, AFM
H. Dai et al. report, in Nature (384, 1996, p. 147), an application of a carbon nanotube to STM and AFM. According to their report, the carbon nanotube prepared by the arc discharge process was an SWNT having a diameter of about 5 nm at the leading end. Because of a thin tip and flexibility, even the bottom of a gap of a sample could be observed, and there was available an ideal tip free from a tip crash.
(3) Hydrogen Storing Material
A. C. Dillon et al. report, in Nature (vol. 386, 1997, p. 377-379), that the use of an SWNT permits storage of hydrogen molecules of a quantity several times as large as that available with a carbon generated from a pitch-based raw material. While their study on application has just begun, it is expected to serve as a hydrogen storing material for a hydrogen car or the like.
In the configuration and manufacturing method of a carbon nanotube in the conventional art, diameters and directions of resultant carbon nanotubes are very random, and after growth, an electrode is not connected to the carbon nanotube. More specifically, upon application of the carbon nanotube, it is necessary to collect after synthesis for purifying, and form it into a particular shape in compliance with the shape for application.
For example, when it is to be used as an election source, A. G. Rinzler et al. teaches the necessity to take out a carbon fiber and to bond an end thereof to an electrode, as reported in Science (vol. 269, 1995, p. 1550-1553).
Further, as reported in Science (vol. 270, 1995, p. 1179-1180) and Science (vol. 1, 268, 1995, p. 845-847), Walt A. de Heer et al. discloses the necessity to provide a step of purifying a carbon nanotube prepared by the arc discharge process, and then placing upright the carbon nanotube on a support by the use of a ceramic filter. In this case, an electrode is not positively bonded to the carbon nanotube. Further, the carbon nanotubes in application tend to get entangled with each other in a complicated manner, and it is difficult to obtain devices fully utilizing characteristics of the individual carbon nanotubes.
The present invention was developed in view of the problems as described above, and has an object to provide a carbon nanotube device, in which a carbon nanotube has a strong directivity, giving a large quantity of electron emission when it is used, for example, as an electron emission device.
Another object of the invention is to provide a manufacturing method of carbon nanotube device in which the carbon nanotube binds to a conductive surface so that conduction is maintained therebetween, and the carbon nanotube has a high directivity.
Further, the invention has an object to provide an electron emission device giving a large quantity of electron emission and having a high performance.
Specifically, there is provided a carbon nanotube device comprising a support having a conductive surface and a carbon nanotube, one of whose terminus binds to said conductive surface at a site so that conduction between said conductive surface and said carbon nanotube is maintained, wherein a root of said carbon nanotube where said carbon nanotube binds to said conductive surface is surrounded by a wall.
Forming the barrier with a layer containing alumina or silicon is preferable with a view to achieving a higher density of the carbon nanotubes binding to the conductive surface. The wall containing alumina is available, after forming an aluminum thin film on the conductive surface, for example, by anodically oxidizing aluminum. At this point, the conductive surface should preferably comprises a layer containing at least one element selected from the group consisting of titanium, zirconium, niobium, tantalum, molybdenum, copper and zinc. It is not necessary that the conductive surface be previously protected even during anodic oxidation of the aluminum thin film.
There is also provided, a manufacturing method of a carbon nanotube device comprising a support having a conductive surface and a carbon nanotube, one of whose terminus binds to said conductive surface at a site so that conduction between said conductive surface and said carbon nanotube is maintained, wherein a root of said carbon nanotube at the site where said carbon nanotube binds to said conductive surface is surrounded by a wall, said method comprising the steps of:
(i) forming a plurality of carbon nanotube binding sites isolated from each other by walls on said conductive surface; and
(ii) forming carbon nanotubes at the sites.
Additionally, there is provided an election emitting device comprising:
a carbon nanotube device, which itself comprises a support having a conductive surface and a carbon nanotube, one of whose terminus binds to said conductive surface so that conduction between said conductive surface and said carbon nanotube is maintained, wherein a root of said carbon nanotube where said carbon nanotube binds to said conductive surface is surrounded by a wall;
an electrode located at a position opposite to said conductive surface; and
means for impressing a potential to a space between said conductive surface and said electrode.
According to the invention as described above, it is possible to control growth direction of the carbon nanotube by means of the wall. As a result, it is possible to provide an electron emitting device having excellent electron emitting properties, and a carbon nanotube device suitable for a probe of an STM or an AFM which gives a satisfactory image and has a high strength.
In the case where the wall comprises a layer containing alumina or silicon, it is possible to efficiently form a carbon nanotube device having a configuration in which a plurality of carbon nanotubes bind to the conductive surface, and binding sites of the individual carbon nanotubes are isolated from each other by the wall. The device of the invention, provided with carbon nanotubes whose growth directions are almost the same, and each of which have a uniform directivity isolated from each other at a high density, is suitably applicable for an electron emitting device or a probe such as an STM or an AFM.
When the conductive surface comprises a layer containing at least one material selected from the group consisting of titanium, zirconium, niobium, tantalum, molybdenum, copper and zinc, it is possible to easily form a carbon nanotube of the invention. More specifically, an alumina thin film having a narrow hole is formed through anodic oxidation also when forming the barrier by anodic oxidation of an aluminum thin film. The anodic oxidation carried out so that the bottom of the narrow hole serves as the electrode surface never damages the conductive surface, and as a result, it is possible to easily form a carbon nanotube binding conductively to the conductive surface.
In the various features of the present invention as described above, the expression xe2x80x9ca terminus of the carbon nanotube binds conductively to the conductive surface of the supportxe2x80x9d include, in addition to the embodiment in which the carbon nanotube binds directly to the conductive surface, an embodiment in which the carbon nanotube is conductively connected to the conductive surface under a tunnel effect via an insulating layer, and an embodiment in which the carbon nanotube binds conductively to the conductive surface through an insulating layer including a path containing an element composing the conductive surface. | {
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1. Technical Field
The present invention relates generally to a system for tracking and monitoring the performance of tools in a multi-user environment and more specifically to a system which networks information from several databases to efficiently associate data to individual tools.
2. Discussion
Tool monitoring systems which monitor the repeatability of tools at an operation level are well known in the art and are commonly used in high-volume automotive factories. These systems largely function at an xe2x80x9coperational levelxe2x80x9d as all data is correlated to the operation which is being performed, rather than to the individual tool performing the operation. This approach has several drawbacks which have not as of yet been identified by the users of such systems.
One drawback of these systems concerns the inability to track and monitor individual tools. The ramifications of this inability affect the integrity of the data collected for an operation, the ability with which the user is able to verify the performance of the tool, the capability to verify that a tool is in a desired location and the ability to perform preventative maintenance on the tool.
The integrity of the data collected for an operation is typically dependent not only on the operation of the tool, but also on the ability of the tool to impact a workpiece in a desired manner. In fastening operations for example, it is not uncommon for different tools to exhibit the same repeatability as measured on test fixtures as measured by dynamic torque checks with in-line torque transducers but have differing impacts on the workpiece due to differences in the design or control of the tool. A common example of one such difference is the speed with which the fastening tools rotate. Significant differences between the rotational speed of two tools may render the impact (i.e., performance) of a tool unacceptable. In system where only the repeatability of the tool is monitored at the operational level, the inability to track and monitor at the tool level leaves the system vulnerable to inadvertent changes in tool assignments, and thus compromises the integrity of the system since only a portion of the information relevant to the quality of the workpiece is monitored.
Another drawback concerns the cross-referencing of information between various disciplines to permit the scheduling of performance verification testing and preventative maintenance. Monitoring and tracking at an operational level does not provide a flexible and current system which permits the user to schedule selected tools for testing and/or maintenance. Tracking at the operation level requires all tools at a given operation to be tested or maintained simultaneously. Such requirements have not been found to be workable as they are highly disruptive to the production environment employing the tool. In an attempt to improve the ability with which tools are tested or maintained, manual systems are often utilized. These manual system typically required substantial duplicative data entry efforts and lacked the ability to automatically update when changes to tool assignments were made. Consequently, changes in tool assignments were not readily incorporated into the schedules for testing and/or preventative maintenance. Therefore, the act of scheduling tests and maintenance on selected tools, as well as the process of maintaining these schedules was extremely labor intensive and fraught with opportunities for error.
Yet another drawback concerns the labor and accuracy with which periodic performance verification tests are configured. Periodic performance verification tests are frequently employed to ensure that a tool is functioning in a desired manner. Configuration of the test for a given tool requires that certain base-lining information be available for use in the analysis of the test data. Examples of this base-lining information include the specification target and the upper and lower specification limits. As this information was not linked to individual tools, manual systems are typically utilized. These manual systems typically required substantial duplicative data entry efforts and lacked the ability to automatically update when changes to tool assignments or specifications were made.
Accordingly, there remains a need in the art for a system for monitoring and tracking tools in a multi-user environment that utilizes information in a network manner to track information to and monitor the location of specific tools.
It is therefore one object of the present invention to provide a system for monitoring and tracking tools in a multi-user environment that utilizes information in a network manner to track the location of specific tools and monitor information at the tool level.
It is another object of the present invention to provide a system for monitoring and tracking tools in a multi-user environment to reduce the effort associated with the scheduling of specific tools for testing and/or maintenance.
It is still another object of the present invention to provide a system for monitoring and tracking tools in a multi-user environment to permit test data to be correlated to a specific tool to permit the tool operation to be compared with the tool performance.
A tracking and monitoring system for tools in a multi-user environment is provided. The system assigns a unique identification number to each tool used in the system which permits the tool to be tracked for purposes of performing operations on the tool, such as periodic performance verification testing and/or preventative maintenance. The system user programs the frequency and time at which the operation is to be periodically performed on a tool, such as performance verification testing or preventative maintenance. The system generates routes which enable the operation to be scheduled and performed on selected tools. Data collected from the operation may be uploaded to the system, permitting the system to monitor the performance and/or operation of the tool. In a preferred embodiment, the system compares tool performance to tool operation and calculates tool set-up parameters to tune the performance of the tool to desired levels.
Additional advantages and features of the present invention will become apparent from the subsequent description and the appended claims, taken in conjunction with the accompanying drawings. | {
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1. Technical Field
Present invention embodiments relate to performing analytics on data stored within data systems, and more specifically, to optimizing performance of analytics by compression of patient centric or patient defined measures within a specified schema that performs such data analytics.
2. Discussion of the Related Art
Healthcare networks have very complicated organization structures. An organization typically comprises multiple source systems (e.g., a source of electronic medical records including electronic health records (EHR), records from a claims system, lab feed, various data sources implementing the HL7 standard, patient satisfaction survey, etc.). Clinically integrated networks (CIN) or galaxies (e.g., a group of organizations) are collections of individual healthcare systems with data sharing agreements. Analytics are applied to various electronic records within the source systems to obtain relevant data based upon queries by end users. Data analytics can be performed within the source systems to determine measures for particular patient populations, where the measures are defined by specifications within a schema used to analyze the data (e.g., an XML type language). However, due to the nature of human defined documents, duplicate codes and/or extraneous codes as well as other types of codes within the measure defined specifications may result in inefficiencies in processing of such specifications. | {
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The present disclosure relates to an X-ray tube, and more particularly, to an X-ray tube generating an X-ray, having a simple structure from which a element necessary for focusing an electron beam, such as a magnetic lens, is removed, and having a nanometer-scale focal spot.
An X-ray source (a nano focus X-ray source) having a nanometer-scale focal spot is required for a non-destructive inspection of an object having a microstructure, such as a semiconductor chip.
In general, a nano focus X-ray source includes an electron source (cathode) generating an electron beam, a focusing unit focusing the electron beam emitted from the electron source, and a target (anode) enabling the focused electron beam to collide with each other to generate an X-ray. Herein, since the electron beam travels inside the X-rays source which is in a vacuum state, a proper vacuum is maintained in a path from the X-rays source to the target by a vacuum container.
The focusing unit is composed of a lens for focusing an electron beam, etc. Since an electrostatic lens has a limitation in demagnification due to an aberration etc., a magnetic lens having one or more stages for high focusing of electron beams is used to focus the electron beam in a nano meter size. The focused electron beam collides with a target of metal material and generates a nano focus X-ray.
In general, a magnetic lens is bulky and heavy, and continuously consumes current in order to form a magnetic field. Thus, the related arts of using the magnetic lens as a focusing unit have a limitation in that an X-ray source has a bulky and heavy shape due to the magnetic lens. | {
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The present invention generally relates to an apparatus for measuring the thickness of a paint coating on a substrate such as a metallic sheet or the like, and more particularly to an apparatus for continuously measuring the thickness of a paint coating by using infrared rays.
Conventionally, color painted metallic sheets and the like have been widely employed in various industrial fields for producing products such as building materials, appliances, food cans, etc. In the case of painting on such metallic sheets, it is important to achieve a desired precise thickness of the paint coating, so that a measuring apparatus with high accuracy has been required for this purpose.
Up to the present, there have been provided measuring apparatuses utilizing radiation, for example, of X rays or .beta. rays. However, these apparatuses have such disadvantages that owing to the strict legal requirements imposed on them, they cannot be readily operated or utilized by unqualified persons, while the measuring accuracy obtainable thereby is not necessarily so high, and therefore, these measuring apparatuses have been extremely limited in their applications.
Recently, there has been provided a measuring apparatus utilizing infrared rays instead of X rays and .beta. rays, for example in the U.S. Pat. No. 3,973,122. This type of measuring apparatus utilizes the characteristic properties such that some part of the infrared rays including a specific wave length can be absorbed by the paint coating comprising high polymer when the rays pass through the paint coating.
The measuring apparatus shown in said U.S. patent comprises a black-body radiator for emitting beams of infrared rays of a predetermined wave length to a film laminated on a substrate, and an electronic pyrometer for receiving the beams of the infrared rays reflected from the surface of the substrate and measuring the thickness of the paint coating on the basis of the intensity of the reflected infrared rays, some part of which has been absorbed by the paint coating in the passage therethrough.
However, the conventional measuring apparatus as described above still has a disadvantage in that a high measuring accuracy cannot be constantly obtained with respect to various kinds of paint coatings. | {
"pile_set_name": "USPTO Backgrounds"
} |
1. Field of the Invention
The present invention relates to a torque transmission device, in particular for a drive train of a motor vehicle driven by an internal combustion engine. The device includes an input part and an output part having a common axis of rotation, around which the input part and the output part are jointly rotatable and twistable relative to one another to a limited degree, and a spring damper arrangement that has at least one energy store and a friction device and is effective between the input part and the output part.
2. Description of the Related Art
DE 10 2009 035 916 A1 discloses a torsional vibration damper, in particular a dual mass flywheel, including a primary mass and a secondary mass that are coupled to each other with respect to relative rotation between the two by a friction device, which friction device includes a support plate, a support disc, and a diaphragm spring, and wherein multiple tabs are arranged on the inner circumference of the diaphragm spring to improve the centering of the friction device during assembly of the friction device.
In accordance with DE 10 2009 035 916 A1, the dual mass flywheel includes a primary mass and a secondary mass that are rotatable relative to each other against the force of an arc spring assembly. The dual mass flywheel has an axis of rotation. The secondary mass includes arcuate cutouts in which the arc spring assembly is supported. The primary mass has channel-like arcuate expansions in which the arc spring assembly is situated.
In accordance with DE 10 2009 035 916 A1, the friction device damps the relative rotation between the primary mass and the secondary mass by dry friction. The damping device includes a support plate that is firmly connected, for instance riveted, to the primary mass, and a support disc that is fixed with respect to rotation about the axis of rotation relative to the support plate, but is displaceable in the axial direction relative to the support plate. A friction control disc is arranged between the support plate and the support disc. The friction control disc is connected to the secondary mass by teeth so as to be axially displaceable and fixed against relative rotation. The friction control disc is in surface contact with the support plate and with the support disc. Thus rotation of the friction control disc relative to the support plate and relative to the support disc is possible against the dry friction between the contacting surfaces. The support disc is pressed onto the friction control disc and the support plate, respectively, by a diaphragm spring, causing the friction control disc to be clamped between the support plate and the support disc. Fingers of the support disc pass through corresponding openings in the support plate. Likewise, fingers of the diaphragm spring pass through openings of the support plate.
The present invention has as an object providing a torque transmission device of the kind described above having a design that is adapted to/optimized in terms of the installation space. | {
"pile_set_name": "USPTO Backgrounds"
} |
This invention relates to a lens-adjustable flash camera and particularly concerns a camera provided with a flashing device and a lens-adjusting means and further capable of changing beam angle of flash light, so as to illuminate appropriate photographic scene corresponding to a photographing angle of a photographing lens.
Flash cameras provided with built-in strobo-flash device have been widely used. With such cameras, photographings in dark scene become very much easier than with conventional standard cameras wherein a flash device must be mounted on a camera and stop of lens and exposure time must be selected taking account of distance of the object. Namely, with the flash cameras, the adjustments of stop and exposure time in relation with the distance have been automatically made.
However, in such camera with built-in flash device, the flash device has been designed for use only with a standard lens of standard focal length. Accordingly, when an auxiliary or adaptor lens for converting the focal length of the photographing lens of the camera or photographing angle of the photographing lens are used, and a photography of narrower scene or wider scene than the standard scene by the standard lens is taken with the built-in flash device unadjusted, the angle of flash light beam is too narrow or too wide for the scene by the adjusted lens. Therefore, defective photographing with flash light illumination only at central part of the scene or too long exposure time due to redundant wide angle lighting takes place. | {
"pile_set_name": "USPTO Backgrounds"
} |
1. Field of the Invention
This invention relates to the manufacture of gaseous mixtures comprising H.sub.2 and CO, e.g., synthesis gas, fuel gas, and reducing gas by the partial oxidation of pumpable slurries of solid carbonaceous fuels in a liquid carrier or liquid or gaeous hydrocarbon fuel. In one of its more specific aspects, the present invention relates to an improved burner for such gas manufacture.
2. Description of the Prior Art
Annulus-type burners have been employed for introducing liquid hydrocarbonaceous fuels into a partial oxidation gas generator. For example, coassigned U.S. Pat. No. 3,528,930 shows a single annulus burner, and coassigned U.S. Pat. Nos. 3,758,037 and 3,847,564 show double annulus burners. However, in such burners, only one pair of reactant feedstreams are mixed downstream from the burner face, and missing are the high turndown, pre-mix, and soot-blowing or de-slagging features of the subject burner.
To obtain proper mixing, atomization, and stability of operation, a burner for the partial oxidation process is sized for a specific throughput. With prior-art burners, should the required output of product gas change substantially, shut-down of the system is required in order to replace the burner with one of proper size. This problem is avoided and costly shut-downs are avoided by the subject burner which will operate at varying levels of output while retaining efficiency, stability, and axial symmetry.
The more complex process for preheating a gas generator by means of a preheat burner, removing the preheat burner from the gasifier, and inserting a separate production burner is described in coassigned U.S. Pat. No. 4,113,445. In contrast, the subject burner may be used for both preheating and production without being removed from the gas generator. | {
"pile_set_name": "USPTO Backgrounds"
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Multi-threshold voltage IC devices are often utilized in the semiconductor integrated circuit (IC) industry to optimize delay or power. A multi-threshold voltage IC device may include several different devices, each having a different threshold voltage (i.e., operating voltage). For example, the multi-threshold voltage IC device may include a low threshold voltage device and a high threshold voltage device. One approach to achieving the different threshold voltage devices includes channel and halo implantation optimization. This implements heavy implantations to achieve the higher threshold voltage devices, and separate masks for each desired threshold voltage. It has been observed that the heavier implantation processes can cause mobility degradation and junction leakage current, and using a separate mask for each desired threshold voltage incurs unnecessary cost. For example, band-to-band tunneling current is high under heavy implantation such that the OFF current is increased. Carrier mobility degradation decreases the ON current.
Another approach, which has been used in conjunction with the channel/halo implantation optimization, includes enlarging a channel length of the higher threshold voltage devices. However, as technology nodes continue to decrease, functional density (i.e., the number of interconnected devices per chip area) has generally increased while geometry size (i.e., the smallest component (or line) that can be created using a fabrication process) has decreased. Enlarging channel lengths to accommodate higher threshold voltage devices thus consumes valuable IC device space, limiting the amount of devices that can be fabricated on a single chip. Furthermore, longer channel length reduces the ON current as well as increases capacitance, hence reducing the speed of device operation.
Accordingly, although existing approaches for fabricating multi-threshold voltage devices have been generally adequate for their intended purposes, they have not been entirely satisfactory in all respects | {
"pile_set_name": "USPTO Backgrounds"
} |
I. Field of the Invention
The present invention pertains generally to the field of communications, and more particularly to generating pilot strength measurement messages in a wireless communication system.
II. Background
In the field of wireless communications, several technology-based standards exist for controlling communications between a mobile station, such as a cellular telephone, Personal Communication System (PCS) handset, or other remote subscriber communication device, and a wireless base station. These include both digital-based and analog-based standards. For example, among the digital-based cellular standards are the Telecommunications Industry Association/Electronic Industries Association (TIA/EIA) Interim Standard IS-95 series including IS-95A and IS-95B, entitled xe2x80x9cMobile Station-Base Station Compatibility Standard for Dual-Mode Wideband Spread Spectrum Cellular System.xe2x80x9d Similarly, among the digital-based PCS standards are the American National Standards Institute (ANSI) J-STD-008 series, entitled xe2x80x9cPersonal Station-Base Station Compatibility Requirements for 1.8 to 2.0 GHz Code Division Multiple Access (CDMA) Personal Communication Systems.xe2x80x9d Other non-CDMA based digital standards include the time-division multiple access (TDMA) based Global System for Mobile Communications (GSM), and the U.S. TDMA standard TIA/EIA IS-54 series.
The spread spectrum modulation technique of CDMA has significant advantages over other modulation techniques for multiple access communication systems. The use of CDMA techniques in a multiple access communication system is disclosed in U.S. Pat. No. 4,901,307, issued Feb. 13, 1990, entitled xe2x80x9cSPREAD SPECTRUM MULTIPLE ACCESS COMMUNICATION SYSTEM USING SATELLITE OR TERRESTRIAL REPEATERS,xe2x80x9d assigned to the assignee of the present invention, of which the disclosure thereof is incorporated by reference herein.
Space or path diversity is obtained by providing multiple signal paths through simultaneous links from a mobile user through two or more cell-sites. Furthermore, path diversity may be obtained by exploiting the multipath environment through spread spectrum processing by allowing a signal arriving with different propagation delays to be received and processed separately. Examples of path diversity are illustrated in U.S. Pat. No. 5,101,501, issued Mar. 31, 1992, entitled xe2x80x9cSOFT HANDOFF IN A CDMA CELLULAR TELEPHONE SYSTEM,xe2x80x9d and U.S. Pat. No. 5,109,390, issued Apr. 28, 1992, entitled xe2x80x9cDIVERSITY RECEIVER IN A CDMA CELLULAR TELEPHONE SYSTEM, xe2x80x9d both assigned to the assignee of the present invention and incorporated by reference herein.
The deleterious effects of fading can be further controlled to a certain extent in a CDMA system by controlling transmitter power. A system for cell-site and mobile unit power control is disclosed in U.S. Pat. No. 5,056,109, issued Oct. 8, 1991, entitled xe2x80x9cMETHOD AND APPARATUS FOR CONTROLLING TRANSMISSION POWER IN A CDMA CELLULAR MOBILE TELEPHONE SYSTEM,xe2x80x9d Ser. No. 07/433,031, filed Nov. 7, 1989, also assigned to the assignee of the present invention. The use of CDMA techniques in a multiple access communication system is further disclosed in U.S. Pat. No. 5,103,459, issued Apr. 7, 1992, entitled xe2x80x9cSYSTEM AND METHOD FOR GENERATING SIGNAL WAVEFORMS IN A CDMA CELLULAR TELEPHONE SYSTEM,xe2x80x9d assigned to the assignee of the present invention, of which the disclosure thereof is incorporated by reference herein.
The aforementioned patents all describe the use of a pilot signal used for acquisition in a CDMA wireless communication system. At various times when a wireless communication device such as a cellular or PCS telephone is energized, it undertakes an acquisition procedure which includes, among other things, searching for and acquiring the pilot channel signal from a base station in the wireless communication system. For example, demodulation and acquisition of a pilot channel in a CDMA system is described in more detail in copending U.S. patent application Ser. No. 08/509,721, filed Jul. 31, 1995, entitled xe2x80x9cMETHOD AND APPARATUS FOR PERFORMING SEARCH ACQUISITION IN A CDMA COMMUNICATION SYSTEM,xe2x80x9d now U.S. Pat. No. 5,805,648, issued on Sep. 8, 1998, assigned to the assignee of the present invention and incorporated herein by reference. When more than one pilot channel can be acquired by the wireless communication device, it selects the pilot channel with the strongest signal. Upon acquisition of the pilot channel, the wireless communication device is rendered capable of acquiring additional channels from the base station that are required for communication. The structure and function of these other channels are described in more detail in the above referenced U.S. Pat. No. 5,103,459 and will not be discussed in detail herein.
The acquisition procedure for searching and acquiring the pilot channel signals from base stations has the purpose of detecting potential candidate base stations for handoff. The viable base station candidates can be divided into four sets. These sets are used to prioritize the pilots and increase the efficiency of searching. The first set, referred to as the Active Set, comprises base stations that are currently in communication with the mobile station. The second set, referred to as the Candidate Set, comprises base stations that have been determined to be of sufficient strength to be of use to the mobile station. Base stations are added to the candidate set when their measured pilot energy exceeds a predetermined threshold TADD. The third set is the Neighbor Set which is the set of base stations which are in the vicinity of the mobile station (and which are not included in the Active Set or the Candidate Set). And the fourth set is the Remaining Set that consists of all other base stations.
In an IS-95A communication system, the mobile station sends an autonomous Pilot Strength Measurement Message (PSMM) when the mobile station finds a pilot of sufficient strength that is not associated with any of the Forward Traffic Channels currently being demodulated or when the strength of a pilot that is associated with one of the Forward Traffic Channels being demodulated drops below a threshold for a predetermined period of time. The term pilot refers to a pilot channel identified by a pilot sequence offset and a frequency assignment. The mobile station sends an autonomous PSMM following the detection of a change in the pilot strength when one of the following conditions are met:
1. The strength of a Neighbor Set or Remaining Set pilot is found above the threshold (TADD).
2. The strength of a Candidate Set pilot exceeds the strength of an Active Set pilot by more than a threshold (TCOMP)xc3x970.5 dB, and a PSMM carrying this information has not been sent since the last Handoff Direction Message (HDM) or Extended Handoff Direction Message (EHDM) was received.
3. The strength of a pilot in the Active Set of Candidate Set has fallen below a threshold (TDROP) for greater than a predetermined time period (TTDROP), and a PSMM carrying this information has not been sent since the last HDM or EHDM was received.
TADD is threshold above which the received signal is of sufficient strength to effectively provide communications with the mobile station. TDROP is a threshold value below which the received signal energy is insufficient to effectively provide communications with the mobile station.
In an IS-95B communication system, the mobile station sends an autonomous PSMM according to one of two sets of rules as chosen by the base station. The first set of rules is the same as the rules specified in IS-95A. The second set of rules uses a dynamic threshold defined as: T DYN = SOFT_SLOPE 8 xc3x97 10 xc3x97 log ∑ i ∈ A ( Pilot xe2x80x83 Ec / Io ) i + ADD_INTERCEPT 2 ,
where the parameters SOFT_SLOPE and ADD_INTERCEPT are specified by the base station and the summation is performed over all pilots in the Active Set. Ec/Io is the ratio of pilot energy per chip to the total received spectral density of noise and signals.
According to the second set of rules of IS-95B, the mobile station sends an autonomous PSMM if any of the following conditions occur:
1. The pilot strength of a Candidate Set pilot is found to be above TDYN, and a PSMM carrying this information has not been sent since the last EHDM or General Handoff Direction Message (GHDM) was received;
2. The pilot strength of a Neighbor Set pilot or Remaining Set pilot is found to be above max(TDYN, TADD/2);
3. The pilot strength of a Candidate Set pilot exceeds the strength of any Active Set pilot by TCOMPxc3x970.5 dB and is above TDYN, and a PSMM carrying this information has not been sent since the last EHDM or GHDM was received;
4. The handoff drop timer of an Active Set pilot has expired and a PSMM carrying this information has not been sent since the last EHDM or GHDM was received.
The rules according to IS-95A and IS-95B are designed for single carrier systems that use a 1.25 MHz channel on both the forward link and the reverse link. However, in a multi-carrier system, the mobile station receives the pilot channel of a base station on multiple carrier frequencies simultaneously. For example, a 3xc3x97/1xc3x97 multi-carrier system may use three 1.25 MHz channels on the forward link and one 1.25 MHz channel on the reverse link. Another example is a 3xc3x97/3xc3x97 multi-carrier system using three 1.25 MHz channels on the forward link and a 3.75 MHz channel on the reverse link. In either example, one can see short term fading that varies from one carrier frequency to another. In such a situation, the IS-95 rules that govern the autonomous transmission of a PSMM are inadequate in the presence of pilots on multiple pilot channels. Hence, there is a present need to determine when a mobile station transmits an autonomous PSMM according to the receipt of multiple pilot signals from base stations in multi-carrier systems.
The present invention is directed to a method and apparatus for generating an autonomous Pilot Strength Measurement Message (PSMM) by a mobile station in a multi-carrier wireless communication system, comprising the steps of receiving a plurality of pilots at a mobile station, wherein the plurality of pilots are transmitted from at least one base station; using a first pilot strength definition from a set of pilot strength definitions to determine a pilot strength associated with at least one of the plurality of pilots; checking a set of rules, wherein the set of rules is for generating the PSMM by manipulating the first pilot strength definition; and generating the PSMM for transmission from the mobile station.
In one aspect of the invention, differing pilot strength definitions are used in the set of rules by applying one pilot strength definition in one rule while applying a different pilot strength definition in another rule. In another aspect of the invention, the PSMM generated by the mobile station carries pilot strength information that was not used to generate the PSMM. | {
"pile_set_name": "USPTO Backgrounds"
} |
1. Field of the Invention
The present invention relates to urological warming and cooling devices and more particularly to a warming catheter and method of warming the urethra of a patient during ablative surgery. The apparatus is particularly useful in cryosurgery to prevent damage to tissues surrounding a surgical site from the extremely cold temperatures employed therein. The apparatus is especially useful during transperineal cryoablation of the prostate gland in human males to maintain the temperature of the urethral tissues and thereby prevent urethral sloughing. The apparatus may also have utility where it is desired to lower the temperature of surrounding tissues, such as during laser ablation.
2. Description of the Related Art
Cryosurgical probes are used to treat a variety of diseases. The cryosurgical probes quickly freeze diseased body tissue, causing the tissue to die after which it will be absorbed by the body, expelled by the body or sloughed off. Cryothermal treatment is currently used to treat prostate cancer and benign prostate disease, breast tumors and breast cancer, liver tumors and liver cancer, glaucoma and other eye diseases. Cryosurgery is also proposed for the treatment of a number of other diseases.
The use of cryosurgical probes for cryoablation of the prostate is described in, for example, Onik, Ultrasound-Guided Cryosurgery, Scientific American at 62 (January 1996). Cryosurgical probe systems are manufactured by present assignee, Endocare, Inc. of Irvine, Calif. In cryosurgical ablation procedures generally several cryosurgical probes are inserted through the skin in the perineal area (between the scrotum and the anus), which provides the easiest access to the prostate. The probes are pushed into the prostate gland through previously placed cannulas. Placement of the probes within the prostate gland is typically visualized with an ultrasound imaging probe placed in the rectum. The probes are quickly cooled to temperatures typically below −120° C. The prostate tissue is killed by the freezing, and any tumor or cancer within the prostate is also killed. The body absorbs some of the dead tissue over a period of several weeks. However, other necrosed tissue may slough off and pass through the urethra, often causing undesirable blockage. Thus, it is often desirable to avoid cryoinjury to the urethra during cryoablation of the prostate. This may be done by placing a warming catheter in the urethra and continuously flushing the catheter with warm fluid to keep the urethra from freezing.
Devices for warming the urethra have been available for quite some time. In 1911, U.S. Pat. No. 1,011,606 issued for an “Appliance For Subjecting Portions Of The Human System To Heat Or Cold.” This device was a coaxial dual lumen catheter intended for the application of therapeutic cooling or heating to the urethra and bladder. Devices for warming other body parts have also been proposed, such as U.S. Pat. No. 4,244,377, issued Jan. 13, 1981 to Grams entitled “Ear Probe For Use In Closed-Loop Caloric Irrigation”, which shows a coaxial dual lumen cannula intended for the application of therapeutic heating inside the ear.
U.S. Pat. No. 5,437,673, issued on Aug. 1, 1995 to Baust, et al., entitled “Closed Circulation Tissue Warming Apparatus and Method of Using the Same in Prostate Surgery” illustrates use of a urethral warming catheter which is used to protect the urethra from cryothermal damage during cryosurgical treatment of the prostate for benign prostate hyperplasia. The Baust patent discloses a coaxial three lumen catheter in which warm saline passes through an outside lumen and is returned through a coaxial second lumen. A third lumen is a urinary drainage lumen centrally disposed within the other two lumens. The catheter is used to heat the urethra while the prostate is being frozen with cryosurgical probes.
A very similar device to that disclosed in U.S. Pat. No. 5,437,673 is disclosed in U.S. Pat. No. 5,624,392, issued on Apr. 29, 1997 to Saab, entitled “Heat Transfer Catheter and Methods of Making and Using Same.”
U.S. Pat. No. 5,257,977, issued on Nov. 2, 1993 to Eshel, entitled “Technique for Localized Thermal Treatment of Mammals,” shows a catheter that delivers heated saline flow to provide therapeutic hyperthermia treatment of the prostate. Like the Baust patent, Eshel shows a three lumen catheter with a centrally located urinary drainage lumen.
Still other devices have been described for importing fluid into the body and allowing a means for removing fluid from the body. One such device is described in U.S. Pat. No. 3,087,493, issued Apr. 27, 1960 to Schossow, entitled “Endotracheal Tube”. Schossow describes a device employed to intubate the human trachea. The device is connected with ducts and/or tubes outside the patient for the purpose of, for example, drawing off from the patient's respiratory tract undesirable liquids and/or introducing beneficial liquids into the trachea. The device comprises an outer tube, which fits inside the patient's trachea, and a two layered inner tube. The lumen of the inner tube is open to be connected with devices or ducts through which suction may be applied or fluids injected into the trachea. The distal portion of the inner tube is vented with ports or openings that create a “sprinkler” effect inside the tube.
During cryoablation, the prostate tissue is killed by freezing temperatures in the cryogenic temperature range, typically −120° C. and below. The hot fluid used for the warming catheter is supplied at about 30° C. to 50° C. Warm fluid is pumped through the urethral warming catheter, such as the catheter described in Baust et al. Using this catheter, as the warm fluid travels the length of the urethral catheter disposed within the cryosurgically-cooled urethra, it is cooled by the surrounding freezing tissue. By the time the hot water has traveled from the bladder neck sphincter to the external sphincter, it has been significantly cooled by the surrounding frozen prostate. As a result, the urethral tissue near the bladder neck sphincter (near the hot water outlet) is heated more than the urethral tissue near the external sphincter, creating a strong thermal gradient in the prostatic urethra and an uneven heating effect. By the time the hot water reaches the external sphincter, it may have lost so much heat to the upper region of the urethra that it is not warm enough to protect the external sphincter from freezing. In order for the tissue at the bladder neck sphincter to be adequately warmed, hotter water must be pumped in, risking urethral damage due to scalded tissue, or more water must be pumped at higher rates and pressures, increasing the material requirements of the hot water supply system and the warming catheter.
U.S. Pat. No. 6,017,361, issued to Mikus et al, entitled “Urethral Warming Catheter,” discloses an improved method and means for maintaining the temperature of urethral tissues during cryoablation of the prostate gland and thereby eliminates or reduces the sloughing of dead cells into the urethra. Diffuser holes or ports, much like a “sprinkler,” are drilled into the inner tube of the warming catheter. The holes create an advantage over the prior art of achieving improved uniformity of fluid flow and temperature, utilizing a lower initial temperature and resulting in a more even application of thermal treatment to the urethral tissues. The apparatus may find additional utility in other areas of surgery where thermal treatment or maintenance of tissues is required with or without the capability of drainage. | {
"pile_set_name": "USPTO Backgrounds"
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In many densely populated urban centers, most notably in New York, public pressure has resulted in recently enacted statutes which require the pet owner to clean up after his pet. This legislation has created a need for a convenient litter retrieving device which allows the pet owner to remove the offensive material with a minimum of effort and to do so as remotely as possible. Devices which are currently available have many drawbacks in their use. They cannot be used after the pet has littered without stooping. The danger exists that the litter would soil the retriever, his clothes, or unintended portions of the retrieving device. Disposal of the litter and/or litter bag again presents an opportunity to befoul oneself. The prior art litter devices generally require use of both hands to effect retrieval of the litter. Previous devices also develop odors if the retrieved litter could not be disposed of immediately after use. Notwithstanding the array of currently available pet litter retrieving devices, there remains a need for a simple, efficient device which eliminates these failings of the prior art. | {
"pile_set_name": "USPTO Backgrounds"
} |
1. Technical Field
The present invention relates to a method and system for performing a maintenance process associated with a communication system.
2. Related Art
A system for connecting multiple devices together typically does not provide much flexibility for detecting a malfunction and providing a solution. Accordingly, there exists a need in the art to overcome at least some of the deficiencies and limitations described herein above. | {
"pile_set_name": "USPTO Backgrounds"
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This invention relates to a process for the preparation of organic fluoride compounds, and in particular, to a process for the liquid phase replacement of halogen atoms with fluorine in organic compounds.
A variety of fluorination processes are known wherein fluorine replaces one or more halogen substituents of a halogenated organic compounds. Such known process include both vapor phase fluorination reaction and liquid phase fluorination reactions. Typically, such processes involve the reaction of a halocarbon compound with a fluorination agent, sometimes in the presence of catalyst, such as antimony pentachloride, at atmospheric or super-atmospheric pressures. Many of the known processes, while suitable for laboratory investigations and experiments, are unsuitable for commercial use for various reasons, such as the low purity or yield of produce, the need for containment of high pressures, the high cost of equipment which must be employed, or the need for freguent replacement of the catalyst, due to loss or deactivation. One of the common difficulties encountered in vapor phase fluorination reactions results from the highly exothermic nature of such reactions. The heat evolved frequently results in a temperature rise sufficient to cause thermal decomposition of some of the organic starting materials and a resultant carbonization of the catalyst. Furthermore, such vapor phase reactions commonly require the use of substantial stoichiometric excess of hydrogen fluoride with the attendant problem of disposal of the hazardous hydrogen fluoride containing effluent gases.
Some of the problems associated with vapor phase fluorination processes may be avoided through the use of liquid phase fluorination. However, although atmospheric liquid phase fluorination processes are known and are used in laboratory preparations, they have not received widespread acceptance for larger scale commercial use for various reasons. Heretofore, the most widely used catalyst for liquid phase fluorinations has been antimony pentachloride or a mixture of antimony pentachloride and antimonly trichloride. However, antimony chlorides, although highly effective in the catalysis of many fluorination reactions, are very volatile materials. To avoid the problems associated with the volatility of antimony chlorides, such fluorination reactions are often carried out in closed systems under super-atmospheric pressure, necessitating the use of pressure equipment. In addition it has been found that to obtain desirably high yields, antimony chloride catalysts must be employed in relatively large concentrations. Thus, although antimony chlorides provide an effective catalyst for many fluorination reactions, a need exists for a still more effective catalyst that will overcome the aforementioned disadvantages.
A wide variety of other fluorination catalysts are known and have been used for various fluorination processes. However, the efficacy of a particular catalyst is highly specific and may depend on the nature of the reactants, that is the specific compound to be fluorinated and the particular fluorinating agent employed as well as the condition of the fluorination reaction, such as temperature, pressure, and physical phase of reactants.
It is an object of the present invention to provide an improved process for the liquid phase fluorination of organic halides. It is a further object to provide an improved catalyst for fluorination reactions that is relatively low in cost, of low volatility, and that may be effectively employed at relatively low concentrations. It is a further object to provide an improved process for the fluorination of organic halides in the liquid phase by reaction with hydrogen fluoride, wherein the hydrogen fluoride may be employed in either concentrated or dilute form. It is a still further object to provide a multi-step fluorination process comprising both a vapor phase and a liquid phase reaction wherein substantial improvements in the effective utilization of hydrogen fluoride reactant are achieved and the amount of hydrogen fluoride waste product is substantially reduced. | {
"pile_set_name": "USPTO Backgrounds"
} |
1. Field of the Invention
The present invention relates to a circuit arrangement for determination of a measuring capacitance.
2. Description of the Related Art
For measuring very small capacitance values or capacitance variations it has been known in the art, for example, to use capacitive proximity switches which have been known since the late sixties. They operate on the principle of influencing an alternating electric field by a dielectric of an object or a medium clearly greater than the dielectric of air or vacuum. Placing such a dielectric in the near field of one or more sensing electrodes leads to a corresponding concentration of electric field lines in that area and, accordingly, to amplification of the electric field. This has the effect to increase capacitance, for example of a plate capacitor in which the dielectric has been placed between its plates, by a small amount. That capacitance variation is evaluated in an evaluation circuit. The evaluation circuit emits a switching signal, for example, when the capacitance rises above a predefined value.
Such capacitive proximity switches are used for applications in the most diverse technical fields. Such applications include, for example, uses for monitoring limit levels of media of any kind, for example aqueous media, granulates, powders, oils and the like. They may be used in submerged condition for determining, for example, the filling level or, in a contactless way, for example by arranging them on the outside of a non-metallic wall of a container for determination of the filling level inside the container for example. Another application consists in scanning and detecting objects over a certain distance, for example in detecting a paper stack, a metallic object, a glass or the like.
Capacitive sensors are operated using electronic circuit arrangements whose functioning modes fall into two main groups, subdivided by their operating principles.
On the one hand, there are oscillating methods where as a rule the oscillating conditions of an oscillator, acting as a closed-loop amplifier, is controlled via an electrode system shortly before oscillation commences. In that case, the electrode system mostly is formed by a capacitive voltage divider, with the measuring capacitance as an integral component. The value of the measuring capacitance influences the overall amplification factor, the phase position and, thus, the oscillatory characteristics. Such oscillator circuits used for detecting small capacitance values and capacitance differences, intended for use in capacitive sensors, have been disclosed, for example, by DE 101 56 580 A1 or DE 1 673 841 A1. Such circuit arrangements and methods permit high sensitivity and/or switching intervals of the capacitive sensors and excellent “sensory qualities”, such as compensation for adhering medium residues, to be achieved with little circuitry input. A disadvantage of such oscillating methods is seen, however, in high susceptibility to interference by alternating electric fields in a wider or narrower bandwidth around the oscillating frequency. Such sensors therefore in many cases fail to meet the EMC immunity requirements, Part IEC61000-4-6.
Other methods for operating the sensors, that exist in addition to the before-mentioned oscillating methods, may be described as “driven ” methods where a generator controls a measuring circuit according to different principles, for example as capacitive bridges, oscillating amplifiers, charge-balancing methods, phase comparators, or the like.
Capacitive sensors that operate on that principle have been disclosed, for example, by DE 199 49 985 A1, DE 197 01 899 C2, EP 1 093 225 B1 or by DE 10 2005 057 558 A1. Although in many cases capacitive sensors that are operated in this way are less sensitive to inference voltage in a wide frequency spectrum it is, however, a disadvantage that such sensors can be realized only with considerably higher circuitry input and in most cases with poorer sensory quality. As used in the present application, the term “sensory quality” relates to the following values or properties: a large adjustable and usable sensitive range, i.e. a large span between the minimally and the maximally adjustable switching interval; little temperature dependence of the switching interval; the capability to compensate for wet, conductive adhering media, in the case of filling level applications; series stability, or independence from component variations.
Presently, there do not exist any capacitive sensors that provide those properties in combination with high EMC immunity. For example, the sensor for contactless detection of the filling level of a highly conductive liquid and adhering medium, such as blood, through a non-metallic container wall of a container, as described by DE 10 2005 057 558 A1, and the method disclosed by that publication actually provide for excellent compensation for adhering media in filling level applications, combined with high interference immunity. But on the other hand, that sensor and the method for contactless detection of the filling level of liquid media do not reach the high switching intervals required in distance sensor technology.
While the method for detection and evaluation of a capacitance variation disclosed by DE 199 45 330 A1, and the sensor described in that publication, permit, for example, high switching intervals to be achieved and high interference levels to be compensated, that sensor does not provide for compensation for adhering ionizing media. | {
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In connection with navigation or route planning, the term “points of interest”, or POIs in short, refers to locations that are of particular interest due to their services, leisure offerings or tourist attractions. Examples for POIs are filling stations, pharmacies, cash dispensers, vehicle repair shops, accommodations, museums, cinemas or other tourist attractions. Modern navigation devices or route planners indicate POIs along a route to be travelled using different multimedia channels and multimedia formats. For instance, POIs may be output in form of visual symbols, sorted POI lists, voice output and so on.
Navigation devices may be configured to provide a continuous POI search along a route to be travelled. The POI search is in this case based on search areas or search corridors of predetermined sizes. One problem associated with the use of search areas of fixed size is that the number of found POIs may vary considerably from search to search depending on the POI distribution along the route. For instance, POI searches along routes going through urban areas may result in large numbers of found POIs, whereas POI searches performed along routes or route portions involving highways or interconnecting roads between towns or cities may only reveal a few POIs.
Further, POI searches in areas of high POI density require a lot of processing resources and may unnecessarily increase the search time. In order to save processing resources and in order to further increase the search performance, search algorithms may be provided with an exit condition so that the search can automatically be aborted. Such an exit condition may constitute the exceeding of a predetermined threshold value for the found number of POI hits. However, depending on the search algorithm, the set of POIs found before aborting the POI search may not be optimal with regard to distance to the route or distance to a user position. Thus, POI search results and POI search performance may strongly depend from route to route.
In addition, when a route is used for navigation, a POI search can be repeated regularly with different sets of results (due to POIs that have already been passed disappearing from the search result, or due to other POIs appearing in the search result that were previously not found because of an exit condition, or due to the route partially or completely changing because of traffic, user deviation from the original route or user input). Due to the local character of POI distributions, the aforementioned problems are likely to reoccur on subsequent repetitions of the search if performed from a position geographically close to the original search. | {
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This invention generally relates to removal of polymer residues following an etching process and more particularly to a method for protecting a wafer backside to prevent etching damage in a wet polymer stripping (PRS) process whereby polymer residues are removed following a metal etching process.
In the fabrication of semiconductor devices multiple layers are required for providing a multi-layered interconnect structure. During the manufacture of integrated circuits it is common to place material photoresist on top of a semiconductor wafer in desired patterns and to etch away or otherwise remove surrounding material not covered by the resist pattern in order to produce metal conductor runs or other desired features. During the formation of semiconductor devices it is often required that the conductive layers be interconnected through holes in an insulating layer. Such holes are commonly referred to as contact holes, i.e., when the hole extends through an insulating layer to an active device area, or vias, i.e., when the hole extends through an insulating layer between two conductive layers. The profile of a hole is of particular importance since that it exhibits specific electrical characteristics when the contact hole or via is filled with a conductive material. In addition, metal interconnect lines may be formed by selectively anisotropically etching away areas (gaps) in a layer of metal to leave metal interconnect lines which are subsequently covered with a layer of dielectric insulating material to fill the gaps.
In anisotropic etching processes, such as those using halocarbon containing plasmas, polymer deposition on the sidewalls and bottom surface of the feature being etched occurs simultaneously with the etching of the oxide or the metal, as the case may be. Surfaces struck by the ions at a lower rate tend to remove the nonvolatile polymeric residual layer at a lower rate, thereby at steady state, leaving a layer of nonvolatile polymeric or metal-polymeric residue on surfaces such as the sidewalls of the etched features, thereby protecting such surfaces against etching by the reactive gas. As such, etching is performed preferentially in a direction perpendicular to the wafer surface since the bottom surfaces etch at a higher rate than the polymeric residue containing sidewalls (i.e., anisotropic etching). If metal is being etched, for example, in etching metal lines, metal will simultaneously deposit with the polymer thus forming a metal-polymer residue on the sidewalls of the etched opening.
In a typical process, for example, an overlying photoresist layer is photolithographically patterned to anisotropically etch the semiconductor features in an underlying layer, for example a metal layer for metal interconnect line etching or an insulating dielectric layer for etching damascene features such as vias or contact holes. After the features are etched, the photoresist mask which remains overlying the upper surface of the etched features may be removed by a reactive ion etch (RIE) process also referred to as an ashing process, for example, carried out in a quartz chamber using a plasma of O2 or a combination of CF4 and O2 to etch the photoresist material.
It has been the practice in the art to remove at least a portion of the photoresist in-situ by an ashing process following an RIE etching procedure where metal is exposed, for instance after anisotropically etching the metal conductive layer, since exposure of the metal to atmospheric conditions can cause metallic corrosion. In such an in-situ ashing process, the photoresist removal may take place by a reactive ion etching (RIE) method using an oxygen containing plasma in an ashing chamber module of a multiple chamber metal etcher.
A processing difficulty arises, however, when a metal-polymer residue forms upon etching a semiconductor feature. In a typical RIE etching process, for example, in etching via openings, etching takes place through the inter-metal dielectric (IMD) layer to expose an underlying metallic contact. Typically the metallic portion is over etched to assure adequate contact of the via opening (which will later be filled with a metallic material) with the underlying metal contact layer. As a result, during the etching process, a metal-polymer residue is formed on the sidewalls of the etched opening that cannot be removed by the RIE ashing process.
Further, the RIE ashing process to remove the overlying photoresist may tend to oxidize the metal-polymer residue formed on the sidewalls of an etched opening thereby making it even more resistant etching in an RIE ashing process. As a result, the metal-polymer residue formed on the sidewalls of an etched opening cannot be successfully removed by an in-situ ashing process and must be additionally cleaned by an ex-situ wet etching process, for example, a wet polymer strip process (PRS).
For example, in a typical wet polymer strip process (PRS) bench configuration wafers are transferred for processing at one or more wet chemical bench process lines. The wafers are typically sequentially immersed in various solutions for a period of time including a primary solvent (wet etching solution) of, for example, ACT available from Ashland Chemical and composed of DMSO (Dimethyl-sulphur-oxide), MEA (Mono-Ethyl-Amine) and catechol typically provided at an elevated temperature. The process wafers are then typically immersed in a neutralizing intermediate solvent solution, for example, n-methyl pyrrolidone (NMP) followed by rinsing solutions of deionized water.
One problem with the prior art wet chemical polymer stripping process is that the wet etching solution including, for example, ACT etches the exposed silicon on the backside of the process wafer. As a result, the backside of the process wafer experiences preferential etching, for example, believed to be related to the dipping or immersion process in the etchant solution carried out in the wet chemical polymer stripping process. As a result, the backside of the process wafer surface is adversely affected by the preferential etching causing difficulties and errors in subsequent photolithographic photomasking patterning steps requiring a level or flat backside surface. For example, due the non-flatness of the process wafer backside following a wet chemical polymer stripping process, leveling difficulties are experienced in the photomasking process leading to defocusing of the photomasked pattern on the process surface. Consequently, semiconductor wafer yields are reduced and wafer manufacturing quality suffers.
There is therefore a need in the semiconductor processing art to develop a method whereby the backside of semiconductor process wafers are protected during a wet chemical polymer stripping process thereby preserving wafer backside flatness.
It is therefore an object of the invention to provide a method whereby the backside of semiconductor process wafers are protected during a wet chemical polymer stripping process thereby preserving wafer backside flatness while overcoming other shortcomings and deficiencies in the prior art.
To achieve the foregoing and other objects, and in accordance with the purposes of the present invention, as embodied and broadly described herein, the present invention provides a method for protecting a silicon semiconductor wafer backside surface during a wet etching process for removing polymer containing residues from a wafer process surface.
In a first embodiment, the method includes providing a silicon semiconductor wafer having a process surface and a backside surface said process surface including metal containing features said process surface at least partially covered with polymer containing residues and said backside surface including exposed silicon containing areas; forming an etching resistant oxide layer over the exposed silicon containing areas; and, subjecting the silicon semiconductor wafer to a series of cleaning steps including a wet etchant corrosive to the exposed silicon containing areas whereby the etching resistant oxide layer protects the backside surface from wet etching.
These and other embodiments, aspects and features of the invention are better understood from a detailed description of preferred embodiments of the invention which are described in conjunction with the accompanying Figures. | {
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In recent years, applications have been developed relating to social networking, Internet of Things (IoT), wireless docking, and the like. It may be desirable to design low power solutions that can be always-on. However, constantly providing power to a wireless local area network (WLAN) radio may be expensive in terms of battery life. | {
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1. Field of the Invention
The present invention relates to an image processing apparatus, an image processing method, and an image processing system which changes a tone of an image.
2. Description of the Related Art
In recent years, with the widespread use of digital cameras, storing photos as digital image data is now quite common. Photos can be browsed in a digital camera used for capturing an image or in a personal computer storing captured image data and thus, there have been changes in how to enjoy photos. First, such technology and the evolution of a photo culture will briefly be described with reference to patent documents.
In the environment described above, so-called digital photo frames have been realized and popularized to be able to enjoy image data in the same manner as printed photos (see, for example, Jpn. Pat. Appln. KOKAI Publication No. 2009-141678).
In such a digital photo frame, photos may be reproduced and enjoyed at a time when one chooses, shown as a slideshow. The digital photo frame can be used as an album terminal to save image data.
Moreover, a digital photo frame capable of connecting to a network and transmitting/receiving mail is proposed (see, for example, Jpn. Pat. Appln. KOKAI Publication No. 2010-61246).
Also, a digital photo frame that allows plural persons to browse so that the display is changed depending on the browsing person by registering information about the number of persons is proposed (see, for example, Jpn. Pat. Appln. KOKAI Publication No. 2010-86194).
Further, a technology (photo-to-painting conversion technology) that enables generation and display of a tone of an image of a different taste (for example, a painting tone), though based on an original photo, by performing image processing thereon is proposed (see, for example, Jpn. Pat. Appln. KOKAI Publication No. 08-44867, U.S. Pat. No. 5,621,868).
Further development of the technology of Jpn. Pat. Appln. KOKAI Publication No. 08-44867 leads to a technology to convert a photo into an artwork of high artistic quality by extracting features such as color information and brush touch information from an image of a painting actually painted by a painter and adding extracted features to a captured photo (see, for example, Jpn. Pat. Appln. KOKAI Publication No. 2004-213598).
Also, a technology to change a quality of image data whose tone such as a painting tone has been converted is proposed (see, for example, Jpn. Pat. Appln. KOKOKU Publication No. 01-46905).
Further, a technology capable of, when plural images are sequentially switched and displayed like a slideshow, effectively preventing an image inappropriate for display from being inadvertently displayed is proposed (see, for example, Jpn. Pat. Appln. KOKAI Publication No. 2009-288507).
On the other hand, because a memory card has increasingly more capacities and lower prices, a case when a family takes photos in plural memory cards by plural digital cameras and piles up photos so that the memory cards are not sorted out is increasing. If it is unknown who took what photo in which memory card, it becomes necessary to check each memory card by reproducing the memory card in a camera or digital photo frame and then to sort out photos for separate folders for storage in a personal computer or the like.
Thus, a technology to automatically sort out photos for each folder according to preset conditions to efficiently sort out photos according to the sorting content when a large amount of images is stored in a personal computer is proposed (see, for example, Jpn. Pat. Appln. KOKAI Publication No. 2009-87099).
Such a conventional digital photo frame has an issue of missing something because only images contained the digital photo frame or recorded in a memory card are simply displayed.
Thus, a proposal is made to connect a digital photo frame to the Internet to deliver various content images for a charge or free of charge (see, for example, Jpn. Pat. Appln. KOKAI Publication No. 2003-91675).
According to the technology of Jpn. Pat. Appln. KOKAI Publication No. 2003-91675, delivery of plural genres of free or charged content such as news and advertisements can be received by the digital photo frame.
A kind of content delivery delivers live video of remote live cameras. If the content delivery technology and the above photo-to-painting conversion technology are combined, live video can also be converted into pictorial video. Live video includes image data of real-time dynamic images or still images switched at fixed intervals uploaded to the server and video of a predetermined period, for example, five minutes, displayed repeatedly to provide a sense of dynamism.
In the foregoing, the evolution of a photo culture and the technical background of digital photo frames have been described. In the trend thereof recently, instead of standalone products, products that can be connected to a network are increasing (see, for example, Jpn. Pat. Appln. KOKAI Publication Nos. 2010-61246 and 2003-91675).
Also, a printer that, in addition to viewing in a screen, prints photo-to-painting converted images is proposed (see, for example, Jpn. Pat. Appln. KOKAI Publication No. 10-84520).
Thus, doing photo-to-painting conversion and printing as illustrated by Jpn. Pat. Appln. KOKAI Publication Nos. 08-44867, 2004-213598, 01-46905, and 10-84520 by using a network can be considered.
However, photo-to-painting conversion has a problem that a longer time is needed for conversion processing with a higher level of algorithm.
Also, a standalone personal printer has a problem that it is difficult for the printer to express a photo-to-painting converted image beautifully, and takes a long time to print. | {
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Field of the Invention
The present invention is generally directed to systems and method for cooling electronics within a computer rack. More specifically, the present invention provides for liquid cooling of assemblies within a computer rack.
Description of the Related Art
Functionality within computing systems in the data center today is being increased. This increase in functionality frequently causes more heat generating electronic components to be included inside of computer racks that house compute blades, such as blade servers of computing equipment. Since more components are being added to computers, less space is available for air flow to cool those components. Since air flow in modern computer systems is limited and electronic components within these systems are at risk of overheating as the density of electronics in a compute blade are increased, what is needed are new methods and systems for cooling electronic components contained within computer systems and within computer racks. | {
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The present invention relates to communication systems in general, and in particular to systems for recording address changes.
With the current advancements in communication technology, most people now have several methods by which they can be contacted. These methods include telephones, fax machines, electronic mail accounts, pagers, etc. In general, each of these devices has a number or address that associates the device with a particular individual or location.
As will be appreciated, the task of updating a list of numbers or addresses used to reach a desired individual can be time-consuming and prone to error. For example, area codes are often modified or people move from one location to another thereby rendering their old telephone number out of date. Currently, most address changes are recorded by a trial and error process. A user calls or attempts to send a message to an old number or address. In the case of a telephone number that has been changed, an error message is played indicating that the number has been changed and the user must record the new number by hand. However, in the case of some technologies, like electronic mail, an error message may be produced that indicates that a message could not be delivered but does not indicate a new address that should be used.
Given the shortcomings in the prior art, there is a need for a method of simplifying the task of maintaining an address book with telephone numbers and/or addresses of desired recipients.
The present invention is a communication system that operates to automatically communicate a change in a number or address of a source communication system. A memory associated with the source communication system stores the numbers or addresses of those destination communication systems that communicate with the source communication system. A new number or address message is generated that indicates the new number or address for the source communication system and the message is transmitted to each of the destination communication systems. The destination communication systems read the new number or address message and update a memory with the new number or address of the source communication system. The destination communication systems preferably transmit an acknowledge signal to the source communication system if they were able to read the message and update the source communication system""s number or address. For those systems unable to read the new number or address message, a voice or text message is generated by the source communication system and transmitted to the destination communication systems in order to inform a human operator of the change in the number or address of the source communication system. The voice or text message may also be transmitted to the destination communication systems that were able to read the new number or address message in order to inform a user that the memories of their communication system have been updated.
The present invention can be used to update the numbers or addresses of a variety of communication systems including telephone systems, facsimile machines or computer systems having an e-mail or Internet Protocol address. | {
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The present invention relates to a plasma processing apparatus and a plasma processing method, and in particular to a plasma processing method of conducting a matching operation with respect to a radio frequency (RF) power supply having periodical repetition of a high output period and a low output period.
In recent years, further high precision of working has been demanded in etching processing using plasma with the progress of miniaturization and integration of semiconductor devices. As a solution for such a problem, it has been known from the past that selectivity of a film of a processing target formed in advance on a top surface of a sample can be improved by changing with lapse of time (temporally), the magnitude or frequency of RF power applied to a sample or electrodes within a sample stage which holds the sample, in order to form bias potential over the sample, or changing power which forms an electric field supplied to form plasma, i.e., conducting the so-called modulation, during processing of the sample of the etching processing target.
Furthermore, it has been known that the amount of deposits which adhere to an inner wall of a processing chamber within a vacuum vessel where plasma is formed and processing on a sample is performed, during processing of the sample, or peeling off of the deposits can be reduced, by periodically repeating increase or decrease of the magnitude (amplitude) of RF power for forming a bias. For example, it has been known to conduct etching by conducting amplitude modulation on RF power for forming bias potential during etching processing with repetition of a high output period and a low output period
As such related art, a technique disclosed in JP-A-2013-012624 is known. JP-A-2013-012624 discloses a plasma processing apparatus or a plasma processing method that facilitates control and cleaning of dust particles by using RF power for forming bias potential having periodical repetition of a high output period and a low output period and thereby causing a quality of material of a film deposited on a surface of a working shape such as grooves and holes of the film of the processing target during processing to become amorphous. | {
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1. Field of the Invention
The present invention relates to a device for sticking a protective sheet on the substrate surface.
2. Description of the Prior Art
When the back face of a semiconductor wafer (also referred to simply as wafer hereinafter) is ground and polished, it is necessary to protect the front face of the substrate in order to avoid damage, and contamination caused by ground dust generated during the grinding work, grinding fluid, or the like. Moreover, the wafer after grinding and polishing has a problem in that it tends to be broken rather easily even by a slight external force because of its surface being irregular due to device pattern, in addition to its being thin and fragile.
For the purpose of protecting the surface during such a wafer processing, a method of sticking a plastic protective tape (protective sheet) made of resin on the surface is well-known as a general technology. Such a technique is disclosed in, for example, Japanese Patent Applications Laid Open, No. Hei 8-148452.
Now, the surface of a wafer in recent years has a conspicuous irregularity due to a pattern formed on the surface. For example, in a wafer with a polyimide film, the thickness of the film is 5 to 20 μm, and the regions of removal of the polyimide film extend even to the outer periphery of the wafer, in an electrode pad section formed in the outer peripheral portion of the pattern for establishing connection with the distributed wires, and in grooves (scribe lines) for chip dicing. Here, the width of the groove is about 50 to 100 μm.
However, even though the surface of the wafer is bonded with a protective surface according to the conventional technique as described in the above, the sheet cannot follow the irregularity of the surface of the semiconductor substrate, resulting in an incomplete adhesion between the protective sheet and the wafer surface.
Referring to FIG. 8, this situation will be described. FIG. 8A is a plan view of a wafer with a protective sheet stuck on, and FIG. 8B is a sectional view at the outer periphery of the wafer. As shown in FIG. 8A, the entire surface of a wafer 101 is bonded with a hatched surface protective sheet 102 by a pressure bonding technique.
When a region 103 shown in FIG. 8A is cut along the outer periphery of the wafer and enlarged, it looks as shown in FIG. 8B. A passivation film 104 composed of a polyimide film is formed on the surface of the wafer 101, and a scribe line 105 is formed in the passivation film 104. The passivation film 104 is bonded from above-by the surface protective sheet 102 consisting of an adhesion layer 106 and a protective layer 107.
However, in the scribe line 105 part having an irregularity, the wafer surface is not fully bonded with the adhesive layer 106, and a gap 108 is thus created. Because of this, during grinding and polishing of the back face of the wafer, the surface of the electrode pad is contaminated by the ground dust or grinding fluid that infiltrates through the gap 108. Presence of such a contamination leads to frequent occurrence of connection failure between the electrode pad and the distributed wires.
Under these circumstances, Japanese Patent Applications Laid Open, No. 2000-038556 discloses a means of filling in the irregularity, in which a sheet having a pressure sensitive adhesion layer that can be melted at a specified melting point and can follow the irregularity is stuck on the wafer, and the entire surface of the wafer is heated.
Since, however, the heating method adopted by the disclosure is one in which all the irregularities are filled by heating the entire surface of the wafer, the adhesive strength of the sheet is enhanced to such an extent that the possibility of cracking the wafer at peeling of the sheet is increased under the condition that the thickness of the wafer after the grinding and polishing is small. Moreover, since the electrode pad for bonding the distributed wires at assembly is formed of a metal with low resistance (mainly aluminum), its surface is oxidized by being heated, forming an insulator layer of metal oxides, which becomes the cause of conduction failure. | {
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The present invention relates to method for increasing the data rate without impairing the signal quality in a communications system for signaling over electric distribution lines from the customers' premises to the distribution substation. This inbound signaling concept has been described in detail in United Kingdom Pat. No. 1,575,026 complete specification published Sept. 17, 1980, the disclosure of which is hereby incorporated by reference.
The basic inbound signaling pattern described in said United Kingdom Pat. No. 1,575,026 occupies two cycles of 60 Hz. FIGS. 1A, 1B, 1C, 2A, 2B, and 3 are reproduced from the corresponding figures in said United Kingdom patent. In order to create a signal pattern for FIG. 1A or 1B a pulse of current is drawn at the customer's meter (on the utility side of the meter) for a very brief period just before the voltage zero-crossing in one of these two cycles; this current does not occur at the same time in the adjacent cycle. Current must flow from the substation to supply this current pulse on the customer's premises; thus the signal can be sensed by examining the current pulse at the substation as shown in FIG. 3. The current pattern produced is very different from that of normal loads that tend to remain the same in successive cycles. Detection of the signal at the substation is performed by subtracting the current in one cycle from the current in the next cycle. If only normal loads are present these currents will be the same in the two cycles and the difference will be zero. In the case of a signal the current pulse is present in one cycle and not in the other. Subtraction leads to either a positive or a negative difference between the two cycles.
To guard against mistaking a change of loads for a genuine signal, the signal pattern is repeated four times to transmit each bit of information reliably. Two current pulses are actually used in the basic signaling pattern. The locations of these pulses within the two cycles of the signaling pattern are shown shaded in FIG. 1C.
An experimental facility designed along the lines described in the referenced U.K. patent was created at the West Methuen substation of Massachusetts Electric Company. Testing revealed that the signal strength attained in this facility was in excess of that required to achieve high quality signaling; it was judged that reliable communication could be achieved using a signal of half the strength used in the test at West Methuen.
By halving the signal strength one could expect to double the data rate. This improved data rate could be realized either by shortening the bit pattern to four cycles wherein the basic pattern of FIG. IC was repeated only twice, or by maintaining the eight-cycle bit but employing therein only the signaling pattern of FIG. 1A or 1B. In this latter option the doubling of the data would be achieved through the use of two simultaneous transmissions. One should note that this approach which employs a single type of signal in each pattern can be implemented using a transmitter with only one silicon controlled rectifier for switching the signaling resistor--by contrast the four-cycle bit approach would require two SCR's to produce the two types of signal pulses.
Emerson Electric Company of St Louis Mo. has been granted a license to build and sell communications equipment based on the technologies pioneered by New England Power Service Co. and described in said United Kingdom Pat. No. 1,575,026 and in U.S. Pat. Nos. 4,106,007 and 4,105,897. An account of the equipment was given recently in a paper entitled "TWACS--the 60 Hz Power-Line System" presented to the Pacific Coast Electric Association on Mar. 13, 1980 by Julius Orban.
The Orban paper describes the technology based upon a bit of duration corresponding to eight periods of the 60 Hz waveform--this is the duration of the bit used as West Methuen test site. The paper reports that more than one inbound message can be transmitted simultaneously (such as might be achieved using the patterns of FIGS. 1A and 1B for two types of bits--as explained above). The paper reports that "up to four" simultaneous messages can be used in the "inbound" (load-to-source) direction presumably by employing the patterns of FIGS. 1A, 1B, 2A and 2B for the four types of messages.
The technology described herein permits signal strength equal to twice that achievable through the use of any one of the signaling patterns of FIGS. 1A, 1B, 2A and 2B in the manner suggested by the Orban paper. In addition it provides up to fourteen simultaneous binary messages with the preferred configuration being up to seven simultaneous messages in quaternary code, using eight-cycle characters.
One may understand the essential feature of the present invention by references to the aforementioned patents and the power-line communication systems described therein. However, one should recognize that the invention is capable of wider application than the specific application detailed above. In fact, it is applicable to any signaling scheme wherein each signaling event is capable, at least in principle, of representing a bit of intelligence. As used herein the term "signaling event" denotes the single application and the subsequent removal of a signaling load. One finds, for example that this invention can be applied to increase signal quality and to simultaneously improve data rate in the "outbound" signaling scheme which is marketed by General Electric Company, Ltd. of England under the name "Cyclotrol". On the other hand, this invention is not applicable to the signaling scheme of Haberly, as described in U.S. Pat. No. 3,509,537, since in that scheme one requires a plurality of signaling events to represent a single bit of intelligence.
In the present invention the signaling patterns can be organized in such a manner that a four-fold increase in signal strength can be realized by lengthening the bit to eight cycles rather than the basic two cycles, and that by lengthening the duration of each pattern one can actually realize an increase rather than a decrease in data rate. This seeming contradiction that the data rate can be increased by employing patterns of longer duration arises from the use of orthogonal patterns of signaling events over intervals that persist for an even multiple of the basic signaling event.
At this point, some attention should be given to the properties of these patterns which have been described previously as "orthogonal". These patterns occur in pairs; the cycles which contain signaling events for one member of the pair do not contain signaling events for the other member, and vice-versa. The signal that is sensed when a member of a pair is detected will be the maximum signal that can be accumulated from the signaling events therein--which implies that all of the samples from cycles containing signaling events are accumulated in the same sense. The signal sensed from the two members of the pair will be equal in magnitude but opposite in sign.
The orthogonal feature is that the detection mode appropriate to the sensing of the members of one pair of patterns will accumulate no net signal if it is applied to any pattern from another pair of patterns. This property must prevail for all detection modes and the associated pairs of patterns--thus, clearly, there will be a limited number of such pattern pairs that can be associated with patterns of a given duration. The totality of the pairs of patterns and their properly associated detection modes which exhibit this orthogonal property can conveniently be referred to as an orthogonal family.
It is contrary to one's intuition that an increased data rate is to be realized through the use of patterns which prolong the duration of individual bits--it is obvious that one can attain an enhanced signal quality through the use of longer patterns, but one would normally expect this to be associated with a reduction in data rate as was the case in the teaching of the above-mentioned United Kingdom patent.
The present invention relates to the manner in which one can attain this simultaneous enhancement of signal quality and of data rate.
The principal object of the invention is the realization of improved data rate while improving signal quality in communication technologies wherein each signaling event is capable, at least in principle, of representing a bit of digital intelligence.
An object of the invention is the realization of simultaneous, synchrous transmissions of multiple noninterfering messages over the same communication medium.
It is a feature of the present invention that number bases greater than two are used in the transmitted messages to produce messages of shorter duration.
It is another object of the invention to achieve an enhanced data rate in transmissions where it is not possible to provide the synchronization needed to permit transmissions from a multiplicity of transmitting sites. | {
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1. Field of the Invention
The present invention generally relates to a display device and more particularly relates to a non-emissive display device that conducts a display operation using the light emitted from a backlight unit.
2. Description of the Related Art
Examples of non-emissive display devices include liquid crystal displays (LCDs), electrochromic displays, and electrophoretic displays. Among other things, LCDs are currently used extensively in personal computers, cell phones and many other electronic devices.
An LCD is designed to display images, characters and so on by changing the optical properties of its liquid crystal layer at the openings of its picture element electrodes, which are regularly arranged in a matrix pattern, with drive voltages applied to those electrodes. Also, in the LCD, each picture element includes a thin-film transistor (TFT) as a switching element in order to control the respective picture elements independently of each other.
However, if each picture element includes a transistor, then the area of each picture element decreases and the brightness drops.
Furthermore, considering their electrical performance, manufacturing techniques and other constraints, it is difficult to reduce the sizes of switching elements and interconnects to less than certain limits. For example, an etching precision achieved by a photolithographic process is usually about 1 μm to about 10 μm. Accordingly, as the definition of an LCD has been further increased and as the size thereof has been further decreased, the picture element pitch becomes smaller and smaller. As a result, the aperture ratio further decreases and the brightness further drops.
To overcome this low-brightness problem, according to a proposed method, a collecting element may be provided for each of the huge number of picture elements of an LCD so that the light emitted from a backlight unit is collected on each of those picture elements.
For example, Japanese Laid-Open Publication No. 2-12224 discloses a transmissive color LCD that uses microlenses. In the LCD of that type, a number of microlenses are arranged as densely as possible on a two-dimensional plane, thereby realizing a bright display as shown in FIG. 15B. Since the microlenses are arranged in such a densest possible pattern, R, G and B color filters (and their associated picture elements) are arranged in a delta pattern such that every set of RGB color filters on a row is shifted from its associated set of RGB color filters on the previous row by one and a half pitches as shown in FIG. 15A. That is to say, the ratio of the picture element pitch in the x direction (i.e., row direction) to the picture element pitch in the y direction (i.e., column direction) is 2: √{square root over ( )}3.
However, to realize the microlens arrangement disclosed in Japanese Laid-Open Publication No. 2-12224, the picture elements of an LCD need to be arranged in the delta pattern at the predetermined pitch.
An LCD with such a delta picture element arrangement achieves the display of a natural video, and therefore, can be used effectively in TV sets, camera finders and so on. However, to present characters, figures and other objects including a lot of lines on personal computers, cell phones and so on, the LCD preferably adopts not so much the delta arrangement as a striped arrangement. In the striped arrangement, normally three rectangular R, G and B picture elements make up one substantially square pixel as shown in FIG. 16. The microlens arrangement of Japanese Laid-Open Publication No. 2-12224 cannot be applied to any LCD with this striped arrangement.
There is an increasing demand for further improvement of optical efficiency in various other non-emissive display devices as well, not just the LCDs described above. | {
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1. Field of the Invention
This invention pertains an ultraviolet fire detection device for detecting fires which uses a phosphor to translate energy from ultraviolet wavelengths down into visible and near infrared wavelengths for detection by a photo-sensitive solid state device which can sound an alarm upon detection of the ultraviolet wavelengths associated with flames. In one embodiment a two window approach is used, the reference window being opaque to ultraviolet wavelengths. In the second embodiment, a prism or diffraction grating is used to separate the light source into its various wavelengths.
2. Description of the Prior Art
In the present state of the art, electro-optical sensing devices, such as silicon solar cells (photovoltaic cells), cadmium selenide and the like are not responsive to light in the ultraviolet region of the spectrum. Those photo-sensitive cells which are enhanced to be sensitive to ultraviolet wave-lengths are also extremely sensitive to emissions in the visible and infrared ends of the spectrum and thus lack the capability of discriminating ultraviolet emissions. Hence, there are no solid state electro-optical devices which can serve as ultraviolet detectors in fire detection devices.
In the present state of the art in ultraviolet fire detection devices, photodiodes are used for detection of ultraviolet light. The vacuum photodiode is essentially a vacuum tube with cesium sulfide or some other cesium salt in it, and it is operated at a very high voltage (from 200 to 300 volts). When a photon enters the quartz envelope of the photodiode, it causes an ionic avalanche of current between the two electrodes of the photodiode. This current is then passed through a resistor which creates a voltage drop. The voltage drop is then amplified and converted into a detection signal.
Photodiodes present many problems in fire detection systems. As vacuum tubes, they are somewhat unreliable. An ultraviolet fire detector must be able to operate under a wide range of temperature extremes. Quartz-enveloped photodiodes are not rugged and cannot withstand temperature extremes. They are susceptible to static electricity, even small amounts. They are too sensitive and will respond to lightening, arc welding and similar phenomena, thus causing false alarms. Because of these problems, a fire detection system using photodiodes must include an elaborate test and diagnostic procedure to be performed regularly to discover devices whose photodiodes have failed. The reliability of a tube degrades raidly because of the loss of hermiticity. When the tube fails, there is no indication of failure from the detector. As the tube loses its vacuum over time, it becomes less and less sensitive. Even though it works with a test lamp, it can be so insensitive as to be useless.
To solve the problems of present ultraviolet fire detection systems, the present invention provides a solid state detection system which eliminates the inherent unreliability of the photodiode vacuum tube and provides a means to translate ultraviolet wavelengths of light to visible wavelengths which can be easily detected by photo-sensitive solid state devices. One can make the photodiode sensitive to any desired frequency from 200 nanometers to 1500 nanometers by adjusting the voltage across the diode and adjusting jthe phosphor element inside the photodiode. The frequency is inversely proportional to the wavelength; the higher the frequency, the higher the energy and the shorter the wavelength. Silicon photovoltaic cells are available which are responsive from 300 to 1000 nanometers. Sunlight is filtered out at 280 nanometers by the ozone layer which acts as a low-pass filter. This layer filters out ultraviolet radiation above 280 nanometers. Thus, if a photosensitive solid state device such as a silicon photovoltaic cell is responsive to 300 nanometers and lower in frequency or from 300 nanometers to 1500 nanometers in wavelength, then the cell is responsive to sunlight. If the cell were used in a fire detection system, the sunlight would be a source of false alarms. To overcome this problem, the present invention utilizes a hosphor layer in conjunction with a solid state photosensitive device, the phosphor serving to translate the wavelength of the ultraviolet radiation into a longer wavelength which can be reliably detected by a photosensitive solid state device.
Various phosphors are available which will fluoresce when exposed to ultraviolet radiation, which has wavelengths shorter than 280 nanometers. In particular one phosphor fluoresces from 210 to 290 nanometers, which is an acceptable range for ultraviolet fire detectors. The phosphor receives an ultraviolet photon which has a relatively high energy and captures it in its crystal structure. The phosphor removes some of the energy and reemits the photon. The reemitted photon, having less energy comes out at a different wavelength of light. The energy surplus is dissipated in the crystal as heat. The phosphor receives irradiation in the ultraviolet range and will glow with a yellow-green color, even though the ultraviolet radiation is imperceptible. The wavelength of light emitted from the fluoresced phosphor is sufficiently long enough to be detected by a solid state photosensitive or photodetection device. Thus, the phosphor translates ultraviolet light in the 220 nanometer range to a yellow light which is in the 580 nanometer range. This latter range is in the middle of the response curve for some silicon photovoltaic cells which are very responsive to light in this color range. Thus, the photovoltaic cell can be made responsive through this translation of the ultraviolet light in the 220 nanometer range to a yellow light in the 580 nanometer range, even though the photosensitive device is not responsive to the untranslated ultraviolet light. Thus, using a phosphor as a wavelength translation means, one can characterize the general band of wavelengths desired, for example, the ultraviolet energy emitted from a flame.
The present invention provides two embodiments which use the ultraviolet wavelength translation phenomenen discussed above in solid state ultraviolet fire detectors. In the first embodiment, two windows are utilized, one of glass and one of quartz. Glass is used in the reference window because it is opaque to ultraviolet radiation. A layer of phosphor is deposited behind the both windows. A photosensitive device is positioned behind each window. The outputs of the photosensitive devices are compared in an operational amplifier. In the presence of normal ambient light, sunlight or artificial illumination, both photo-sensitive cells will detect the same amount of light energy, both outputs are the same, and no alarm will be sounded. However, if there is a flame in the environment, the ultraviolet radiation from the flame will pass through the quartz window, cause the phosphor to fluoresce and cause the resulting yellow light to be detected by the photosensitive cell behind the quartz window. At the same time, the glass window which is opaque to ultraviolet radiation will not permit the phosphor behind it to fluoresce, but will detect only the ambient light in the environment. Hence, the glass window and its phosphor layer will cause its photosensitive cell to send a reference signal relative to the ambient light to the operational amplifier. Since the photosensitive cell behind the quartz window will detect both the ambient light and the yellow light from the fluorescent phosphor, this photo-sensitive cell will send a different signal with a greater output to the operational amplifier. The operational amplifier will then cause an alarm.
In the second embodiment, phosphor is also used as the ultraviolet wavelength translation medium. In this embodiment, a quartz prism or diffraction medium is used to separate the wavelengths of light and to project them on a phosphor coated screen. A photosensitive cell positioned behind the screen will detect the fluorescense of the phosphor in the presence of ultraviolet radiation and its output will then exceed a threshold level, causing an alarm to sound. Using a plurality of cells behind a plurality of locations on the prism or diffraction medium, the photosensitive detectors can detect various selected wavelengths of light and thus distinguish between different types of fires such as a hydrogen fire, a butane fire or a propane fire. The fire detection device can be further utilized to select the appropriate extinguishing agent for the type of fire detected.
In all embodiments, the invention used solid state photosensitive devices to detect ultraviolet light of specific frequencies by using a phosphor to translate the wavelength of the ultraviolet radiation to a wavelength in the response range of the photosensitve device. Changes in basic ambient light are ignored by use of a reference cell. When ultraviolet light is present in the spectrum, that light impinging on the quartz sampling cell will be enhanced by the emissions from the phosphor, this enhancement providing a greater output causing the operational amplifier to sound an alarm. | {
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An output node (FBN) of a conventional PMIC can merely output an identical direct current (DC) level. When it is desired to control a low level VGL (e.g., different voltage levels are required at the start-up moment and during the operation, or the low level VGL is required when detecting different images or different temperatures), a printed circuit board assembly (PCBA) needs to be provided with an additional control circuit. At this time, the circuits on the PCBA and the layout thereof need to be changed, and more space needs to be provided for elements on the PCBA. | {
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1. Field of the Invention
The present invention relates to a liquid crystal sealant, a liquid crystal display device using the same, and a method for producing the device. More particularly, it relates to a heat-curable liquid crystal sealant which is excellent in screen printability in producing a liquid crystal display device and can provide a liquid crystal display device high in reliability in moisture resistance, a liquid crystal display device produced using the sealant, and a method for producing the device.
2. Description of the Related Art
In producing a liquid crystal display device using a heat-curable liquid crystal sealant, the upper and lower substrates are laminated by a process which comprises coating the liquid crystal sealant on the substrates by a dispenser or a method such as screen printing, then usually pre-curing (volatilization of solvent) the coat by heating, thereafter putting the upper and lower substrates together in high precision using an alignment mark, and then hot pressing the sealant.
Recently, in producing liquid crystal display devices, substrates become larger in size and tact time (time required for one step) is shortened for further increasing the mass-productivity. The registration step for the upper and lower substrates in laminating the upper and lower glass substrates of a color filter substrate and an array substrate after the pre-curing step is also required to be high in speed and precision. With increase in the size of substrates, especially in the case of beveling for liquid crystal panels of portable telephones, the coating area of the liquid crystal sealant increases, which requires a large torque at the time of registration to cause increase of tact time.
Furthermore, in producing liquid crystal display devices, there is a step of carrying the laminated upper and lower substrates to the subsequent processing step in such a state as the liquid crystal sealant being uncured after the steps of lamination, registration and pre-curing of the upper and lower glass substrates of a color filter substrate and an array substrate. When they are carried by vacuum chucking the upper substrate of the laminated upper and lower substrates which is called vacuum chucking method, there sometimes occur slippage or separation of the laminated upper and lower substrates from each other owing to low tackiness of the liquid crystal sealant. This problem becomes serious with increase of the weight of substrates caused by the recent increase of the size of substrates.
Moreover, with recent increase in minuteness of liquid crystal display devices and response speed of liquid crystal compositions and narrowing of frames, liquid crystal sealants are demanded to have high adhesion and reliability in moisture resistance. Unless the liquid crystal sealants are excellent in reliability in moisture resistance, water contained in air infiltrates through the liquid crystal sealants to contaminate the liquid crystal composition in the liquid crystal display device, resulting in inferior display.
Liquid crystal sealants excellent in adhesion and reliability in moisture resistance are disclosed, for example, in JP-A-11-15005. However, since these liquid crystal sealants disclosed in Patent Document 1 are high in viscosity after pre-curing, operability of registration after lamination of the substrates is insufficient or they are inferior in tackiness after pre-curing, and hence there is a possibility of occurrence of slippage of the upper and lower substrates during vacuum chucking type carrying operation.
Thus, it is strongly demanded to develop liquid crystal sealants which are excellent in adhesiveness and reliability in moisture resistance, high in registration operability at the time of lamination, and do not cause slippage or separation of substrates in vacuum chucking type carrying operation. | {
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The present invention is contemplated for use with underground channel boring systems, the invention being adapted to simplify and expedite the installation of pipes into such underground channels. In typical applications, underground channels are bored between two predetermined points, which points are typically exposed to the surface for access by personnel and/or equipment. A particular such channel boring operation provides for initial boring by a linearly-driven pilot tube, which pilot tube establishes a pathway for which channel boring augers may follow from a starting point to an end point.
Preferably, the starting and ending points for channel boring are defined by personnel/equipment shafts which extend upwardly to the ground surface. In such a manner, boring equipment and pipes may be staged, assembled, or disassembled within respective personnel/equipment shafts. Typically, however, the bored channels are too long for a single pipe section to be brought into the respective personnel/equipment shafts and subsequently positioned within the bored underground channel. Therefore, the underground pipes must be assembled from a plurality of pipe sections that are sequentially inserted into the underground channel. Systems available today for installing such pipe sections are relatively time consuming and expensive. In addition, available means for holding adjacent pipe sections together during the pipe insertion process are typically not strong enough to reliably insert such pipe sections into a bore having an inner diameter substantially similar to the outer diameter of the sectioned pipe. Forces exerted on the sectioned pipe, particularly at the respective connection points, can result in undesired separation of the pipe sections.
Therefore, it is a primary object of the present invention to provide a means for installing a plurality of mutually secured pipe sections into an underground channel in an expeditious and cost-effective manner.
It is a further object of the present invention to provide a means for internally grasping and maintaining adjacent pipe sections in axially connected relationship with one another during insertion thereof into a bored channel.
It is a still further object of the present invention to provide an internal tensioning means for selectively and repositionably grasping adjacently connected pipe sections, which tensioning means is configured so as to be manipulated by existing equipment used for boring underground channels. | {
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The present application relates to a semiconductor device.
The losses associated with switch mode power supplies depend on the resistance of the FETs used in the circuit as well as the charge utilized by the driver during the switching event. At higher frequencies, the losses associated with charge, Qg, Qgd, etc., become large, while at high currents, the losses associated with resistance becomes large. The resistance of a device decreases with larger device width and smaller pitch (because of reduced channel and contact resistance), while the switching charge increases, which leads to a trade off between resistive and switching losses. When deciding on optimal device size, performance is generally evaluated by the R*Q product of a device. There are a few strategies for changing the RQ product. One strategy is to change the density of the two-dimensional gas (2-DEG) over the entire wafer during the formation of the III-nitride heterojunction, which leads to a penalty in drift resistance and associated RA product. Another approach is to change the 2-DEG charge in the entire region under the gate during device fabrication. Reducing the charge under the gate lowers the threshold voltage and capacitance. There are a number of ways to reduce the charge under the gate including, recess etching of the gate region, shallow implantation, and using p-type gate materials. The current processes, such as gate recessing, are difficult to control. A standard etching tool will have 10-20% variation across a wafer, which leads to a similar variation in threshold voltage across the wafer.
The invention disclosed here addresses a fundamental limitation to power management in the switch mode power supplies. Specifically, according to an aspect of the present invention, the gate charge is charged without changing the device gate width. More specifically, in a device according to the present invention, instead of reducing the charge under the gate to reduce the gate charge, the gate area is reduced by interrupting conduction under the gate which will reduce both the gate capacitance and conductivity with a smaller impact on resistance since the total ohmic contact area has not been affected. Furthermore, in a device according to the present invention, the size and the density of the ohmic contacts do not need to be adjusted as would be required when there is a blanket reduction of charge in the channel. Moreover, there will be no change in the threshold voltage of the device as may be the case when the charge is reduced in the entire region under the gate. Threshold voltage will not change since the charge density under the unaffected gate area has remained the same. Thus, the threshold voltage, gate charge, and device resistance can be tuned independently.
Advantageously, a process for fabricating a device according to the present invention will be easer compared to processes that require blanket gate charge density reduction. Moreover, the approach disclosed herein is dramatically reduces process influence on device characteristics.
Other features and advantages of the present invention will become apparent from the following description of the invention which refers to the accompanying drawings. | {
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This invention relates to hair treatment compositions. In particular the invention relates to hair treatment compositions comprising a phase formed from a particular type of gel.
A suspending agent is commonly employed in hair treatment compositions to improve stability against phase separation and settling of suspended materials.
Examples of commonly used suspending agents include crystalline suspending agents (such as ethylene glycol distearate) and inorganic structurants (such as swelling clays). Although these materials are effective for suspending particulate matter, they can adversely affect lathering performance and impart an undesirable cloudy appearance to the composition. Furthermore, during use of the composition they tend to get co-deposited along with the ingredients it is desired to deposit, which can lead to dulling of the hair through excessive build up and reduced performance.
The prior art also proposes the use for suspending purposes of hydrophilic polymers which disperse in aqueous media. Natural polymers have been used for this purpose, and in particular xanthan gum has been used. Personal washing products, especially shampoos, containing xanthan gum are described for example in U.S. Pat. No. 5,286,405 and GB-A-2188060.
A problem is that the resulting products often have an unacceptable xe2x80x9cstringyxe2x80x9d texture and a slimy feel.
One category of synthetic polymers used for suspending purposes are carboxyvinyl polymers. The carboxyvinyl polymers are colloidally water soluble polymers of acrylic acid cross-linked with polyallylsucrose or polyallylpentaerythritol, obtainable under the CARBOPOL trademark from B F Goodrich. U.S. Pat. No. 5,635,171 describes a transparent or translucid gel based on such polymers, in which the gel is rigidified by the incorporation of a very small quantity of an aqueous solution of galactomannan (carob, guar or tara gum). This rigidification enables the stabilization of suspended phases.
A problem is, however, that carboxyvinyl polymers of the above described type can be difficult to formulate because of, inter alia, their sensitivity to pH and ionic strength and their incompatibility with ethoxylated surfactants.
A number of polymers of biological origin, when in aqueous solution, have the ability to form so-called reversible gels which melt when heated but revert to a gel when cooled down subsequently. One well known example of a polysaccharide which forms reversible gels is agar. An aqueous solution containing a small percentage of agar is a mobile liquid when hot, but when left to cool it forms a gel with sufficient rigidity to maintain its own shape. Other naturally derived polymers which can form reversible gels are carrageenan, furcelleran, gellan and pectin.
The formation of gels by natural polysaccharides arises from interaction between the polymer molecules. Reversible gels generally display a melting temperature or temperature range, referred to as the gel point. This is the temperature at which, on slow heating, the gel is observed to melt as this interaction largely disappears. Thus, above the gel point, the hot solution of polymer is mobile. When it cools below its gel point, the interaction of polymer molecules enables them to form a continuous and branched network which extends throughout the sample. In contrast with the formation of a continuous, branched network, some other materials which thicken water do so through merely local, transient entanglement of molecules. A discussion of polysaccharide gels, including their range of mechanical properties, is found in xe2x80x9cGels and Gellingxe2x80x9d by Allan H Clark which is Chapter 5 in Physical Chemistry of Foods, Schwartzberg and Hartel, editors; published by Marcel Dekker 1992. In some instances there is hysteresis and the melting and setting temperatures are not identical.
The melting temperature of a gel can suitably be measured by placing a steel ball, having a diameter of approximately 1 mm, on the surface of a sample which is fully set, then raising the temperature slowly, e.g., in a programmable water bath. The gel melting point is the temperature at which the ball begins to sink through the sample. Apparatus to facilitate such determinations is available, for example as a Physica AMV200 rolling ball viscometer from Anton Paar KG.
A reversible gel also displays a transition temperature at which, upon slow temperature increase, all ordering, be it of microscopical or macroscopical extent, has disappeared completely. This transition temperature (from order to disorder) can be measured by means of differential scanning calorimetry (DSC). The transitions temperature of a reversible gel, as measured by DSC, usually approximately coincides with gel melting, observable visually.
EP-A-355908 teaches that polysaccharides which are capable of forming a reversible gel can be used to form viscous, yet mobile, fluid compositions by subjecting the composition to shear while gel formation takes place. The resulting compositions can be termed xe2x80x9cshear gelsxe2x80x9d.
We have now found that hair treatment compositions comprising a continuous phase formed from such shear gels display excellent resistance to phase separation and settling of suspended materials. The shear gels are tolerant to the presence of surfactant, and may under some circumstances boost the conditioning performance of the hair treatment composition.
WO98/08601 describes aqueous compositions such as liquid personal cleansers containing large hydrogel particles formed by two different water soluble polymers. The hydrogel particles trap water insoluble benefit agents in a network formed by these two polymers. The system is not a shear gel since it is prepared by first forming elongated polymer gel noodles which after gel formation are subsequently cut/broken into the desired gel particle size. The second polymer (which is typically an acrylic polymer such as CARBOPOL referred to above) is required to modify gel strength in order to help stabilize benefit agent in the polymer hydrogel system.
WO95/12988 refers to suspensions or dispersions of gelled and hydrated biopolymer particles for use in food or personal care products to impart a fatty-like character to the product. This system is not a shear gel since particulation of dry material at a temperature equal to or above T(gel) is followed by hydration of the particles at a temperature lower than T(gel), the term xe2x80x9cT(gel)xe2x80x9d denoting the temperature at which, upon cooling, an aqueous solution of the biopolymer concerned, sets to a gel.
In a first aspect, the present invention provides a hair treatment composition which has a thickened fluid form comprising:
(i) a first (shear gel) phase comprising at least one naturally derived polymer which is capable of forming a reversible gel, which polymer is present in the composition as a shear gel (i.e., a multiplicity of separate gel particles which have been formed by subjecting the polymer to shear while gel formation takes place), and
(ii) a second (suspended) phase suspended therein.
In a second aspect, the invention provides the use of a shear gel as a suspending system in a hair treatment composition.
In the present specification, the expression xe2x80x9cthickened fluidxe2x80x9d is used to denote a composition with viscosity greater than that of water.
In order that the gel particles remain stable in the presence of surfactant (which will normally be present in hair treatment compositions of the invention), it will generally be desirable that the polymer does not require polyvalent cations in order to form the precursor aggregates that are subsequently capable of intermolecular association leading to formation of a gel network. Consequently, it is desirable that the polymer is capable of forming a reversible gel when dissolved at a sufficient concentration in hot distilled or demineralised water and allowed to cool to an ambient temperature of 20xc2x0 C.
Compositions embodying this invention may be made with viscosities in a wide range. At one extreme, the compositions may be freely mobile, self-levelling and pourable, although thicker than water. On the other hand, they may be made as viscous liquids which can be squeezed from a collapsible container, and yet which are too viscous to pour, except very slowly.
They are shear-thinning, which can be a useful property in hair treatment compositions such as shampoos and conditioners, because the user can perceive the product as thick and viscous, and yet find it easy to apply. An advantage of viscous shear gels is that they are good at retaining the shape which has been squeezed out, and so can be dispensed by methods other than simple pouring such as from flexible or deformable squeeze tubes.
If the compositions are heated to a temperature above the melting and transition temperatures, the individual gel particles will melt and will not reform as separate particles on cooling, but this will not be a problem in ordinary use, because reversible gels generally have melting temperatures well above normal room temperatures.
Viscosity of compositions embodying this invention can be measured using the same techniques as are used to measure viscosities of other thickened liquid compositions. One suitable apparatus is the Haake Rotoviscometer, another is the Carri-Med CSL 500 viscometer.
Many compositions of this invention will display a viscosity in a range from 0.1 Pa.s to 1000 Pa.s at a shear rate of 10 secxe2x88x921 measured at 20xc2x0 C.
One route for the preparation of the sheared gel particles required for this invention starts with the provision of an aqueous solution of the polymer, at a temperature above the gel melting temperature (and probably also above its order to disorder transition temperature), then cooling the solution to a temperature below the gel setting temperature, while applying shear to the composition. Generally, the solution will be subjected to shear while cooling from 60xc2x0 C. or above to 25xc2x0 C. or less.
On a small scale, this may be carried out in a beaker with a mechanical stirrer in the beaker, providing vigorous stirring while the contents of the beaker are allowed to cool.
We prefer to carry out the preparation using a scraped surface heat exchanger. This may be equipped to operate under a partial vacuum to reduce the incorporation of air bubbles into the composition as gel formation takes place.
Another possibility for preparing the gel particles is to form a bulk quantity of the gel and then break this up into small particles, for instance by pumping it through a homogeniser.
We have found that for many polymers gel formation is inhibited by the presence of surfactant (which is normally a component of hair treatment compositions), and yet gel particles which have already been formed remain stable if surfactant is added subsequently.
Therefore, generally it will be desirable to form the gel particles by cooling an aqueous solution of the gel-forming polymer in the substantial absence of surfactant, and then add surfactant subsequently. An alternative approach is to incorporate surfactant into the aqueous composition before the step of cooling under shear, but this is not possible for all gel-forming polymers.
Thus, in a further aspect, this invention provides a method of preparing a hair treatment composition as set forth above which comprises forming a hot, mobile aqueous solution of the polymer, cooling the solution through its gel temperature, subjecting it to shear during or after cooling, and incorporating surfactant possibly before but preferably after cooling through the gel temperature.
A laboratory-scale scraped surface heat exchanger which we have used successfully is the ESCO Labor mixer available from ESCO Labor, CH-4125, Reihen, Germany.
Scraped surface heat exchangers and homogenisers are used in the commercial production of margarine and other spreadable foodstuffs and such apparatus may be used to produce compositions of this invention on a larger scale. A discussion of such heat exchangers is given by Harrod in Journal of Food Process Engineering 9 (1986) pages 1-62. Suppliers of such apparatus include Armfield Ltd, Ringwood, Hampshire, England, Contherm Corporation which is a division of the Alfa-Laval Group, USA and APV Projects (Crepaco) Ltd, Crawley, West Sussex, England.
After the formation of gel particles, the addition of surfactant or other ingredients, probably as a liquid concentrate, can be carried out using conventional mixing apparatus, operating at low shear. Possibly a scraped surface heat exchanger used to form the gel particles can also be used for a subsequent mixing operation, especially if run more slowly, so as to give lower shear. A mixing operation should not be allowed to heat the composition sufficiently to cause the melting of the gel particles. If necessary, a composition containing gel particles should be cooled before and/or during any subsequent mixing operation. | {
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With the enhancement in the quality of multimedia contents, a high quality multichannel audio signal, such as a 7.1 channel audio signal, a 10.2 channel audio signal, a 13.2 channel audio signal, and a 22.2 channel audio signal, having a relatively large number of channels compared to an existing 5.1 channel audio signal, has been used. However, in many cases, the high quality multichannel audio signal may be listened to with a 2-channel stereo loudspeaker or a headphone through a personal terminal such as a smartphone or a personal computer (PC).
Accordingly, binaural rendering technology for down-mixing a multichannel audio signal to a stereo audio signal has been developed to make it possible to listen to the high quality multichannel audio signal with a 2-channel stereo loudspeaker or a headphone.
The existing binaural rendering may generate a binaural stereo audio signal by filtering each channel of a 5.1 channel audio signal or a 7.1 channel audio signal through a binaural filter such as a head related transfer function (HRTF) or a binaural room impulse response (BRIR). In the existing method, an amount of filtering calculation may increase according to an increase in the number of channels of an input multichannel audio signal.
Accordingly, in a case in which an amount of calculation increases according to an increase in the number of channels of a multichannel audio signal, such as a 10.2 channel audio signal and a 22.2 channel audio signal, it may be difficult to perform a real-time calculation for playback using a 2-channel stereo loudspeaker or a headphone. In particular, a mobile terminal having a relatively low calculation capability may not readily perform a binaural filtering calculation in real time according to an increase in the number of channels of a multichannel audio signal.
Accordingly, there is a need for a method that may decrease an amount of calculation required for binaural filtering to make it possible to perform a real-time calculation when rendering a high quality multichannel audio signal having a relatively large number of channels to a binaural signal. | {
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1. Field of the Invention
The present invention relates to a mousepad, and more particular to a multi-function wireless power induction mousepad.
2. Description of the Prior Art
A mousepad is essential to computer peripheral devices. Through the special design of the surface of the mousepad, the mouse can slide correctly on the mousepad to bring accurate movement of the cursor so that the user can input commands through the mouse.
However, the mousepads on the market only provide the function that the mouse slides thereon, without other additional functions. If the mousepad has other functions to enhance its added value, the user may have more interest in purchasing the mousepad. Accordingly, the inventor of the present invention has devoted himself based on his many years of practical experiences to solve these problems. | {
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Heat pump HVAC units have been used for some time to heat and cool spaces that people occupy such as the interior of buildings. Heat pumps have also been used for other purposes such as heating water and providing heat for industrial processes. Heat pumps are typically more efficient than alternative heat sources, such as electrical resistance heating, because heat pumps extract heat from another source, such as the environment, in addition to providing heat produced from the consumption of electrical power. As a result, heat pumps often reduce energy consumption in comparison with alternatives.
More broadly speaking, a heat pump is a machine or device that transfers thermal energy from one location, at a lower temperature, to another location, which is at a higher temperature. Accordingly, heat pumps move thermal energy in a direction opposite to the direction that it normally flows. Thus, air conditioners and freezers are also types of heat pumps, as used herein. Some types of heat pumps are dedicated to refrigeration only, some types are dedicated to heat only, and some types perform both functions, for instance, depending on whether heating or cooling is needed at the time. Further, in some applications, the heating and the cooling are both put to beneficial use at the same time.
In many applications, heat pumps extract heat from air, such as outdoor air, when a heat pump is being used to provide heat. In other examples, heat pumps extract heat from air that is being cooled such as air in a freezer when the heat pump is being used to cool the freezer. When a heat pump is used to extract heat from outdoor air, if the outdoor air temperature is close to or below freezing, moisture in the air can be deposited onto the outdoor air heat exchanger of the heat pump forming frost on the heat exchanger. The same may occur on a heat exchanger used to cool a freezer or refrigerator, as other examples. Build up of frost on the heat exchanger can interfere with heat transfer from the air to the refrigerant in the heat pump. Specifically, frost can insulate the heat exchanger, or can even block air flow through the heat exchanger. To address this problem, heat pumps have been operated in a defrost mode during a brief defrost cycle, during which the heat exchanger is warmed to melt the frost.
For example, heat pumps that are used in an HVAC application to heat and cool a building, when being used in a heating mode, may interrupt the heating mode periodically to run a defrost cycle. In the defrost cycle, the heat pump may be operated in the cooling mode, except without the outdoor air fan running. In this mode, hot refrigerant gas is delivered to the outdoor air heat exchanger heating the heat exchanger and melting frost that has accumulated on the heat exchanger. After the defrost cycle has been completed, the heat pump returns to the heating mode until another defrost cycle is initiated.
In recent years, microchannel heat exchangers have replaced other types of heat exchangers in various applications including automobile air conditioning. Microchannel heat exchangers typically have a first header, a second header, and multiple cross tubes extending from the first header to the second header. See U.S. patent application Ser. No. 12/561,178, Publication 2010/0071868, for example. Usually, each of the multiple cross tubes directly connects at one end to the first header and each of the multiple cross tubes directly connects at the other end to the second header. Moreover, in microchannel heat exchangers, the first header is often parallel to the second header, the multiple cross tubes are often parallel to each other, the headers are often perpendicular to the cross tubes, and the multiple cross tubes typically each include multiple contiguous parallel refrigerant passageways therethrough (e.g., extending from the first header to the second header). These refrigerant passageways are typically smaller than refrigerant passageways in prior heat exchanger designs (e.g., tube and fin heat exchangers), which is the origin of the name “microchannel”. Furthermore, most microchannel heat exchangers include multiple fins between the cross tubes, and the fins are typically bonded to the cross tubes. Microchannel heat exchangers generally offer a relatively high effectiveness relative to their cost and the restriction that they provide, in comparison with prior heat exchangers used for similar purposes. Microchannel heat exchangers generally also require less refrigerant, in comparison with prior heat exchangers used for similar purposes, and are also generally smaller and lighter in weight than alternative heat exchangers providing equivalent performance.
Microchannel heat exchangers have also been used in place of other types of heat exchangers in residential air conditioning units. In heat pump HVAC units, however, it has been found that microchannel heat exchangers do not defrost as well as certain prior heat exchangers. For example, if during a defrost cycle, hot refrigerant gas is introduced into the first header and travels though the cross tubes to the second header, the second header and the ends of the cross tubes that are connected to the second header often have not gotten warm enough to melt all of the frost there within a desired amount of time. As a result, frost or ice may remain on this portion of the heat exchanger after the defrost cycle is ended, or it may be necessary to extend the defrost cycle and remain in the defrost mode for a longer time.
Microchannel heat exchangers have been know for years to offer performance advantages, particularly relative to cost, size, weight, and the amount of refrigerant that is needed, in comparison with other types of heat exchangers. A long-felt need has existed to use microchannel heat exchangers in HVAC applications, but attempts to use microchannel heat exchangers for outdoor air heat exchangers in heat pumps have failed due to problems defrosting this type of heat exchangers. Others have taken many different approaches to resolving these problems, but none of their efforts have been successful and no heat pumps have been marketed that use a microchannel heat exchanger for the outdoor air heat exchanger.
U.S. Pat. No. 4,407,137 (Hayes) concerns a method and apparatus for defrosting a heat exchanger (50) having multiple rows (52 and 54) of cross tubes (Abstract, FIGS. 1 and 2, col. 3, lines 7-31). In Hayes, a solenoid valve (92) is opened during the defrost cycle to allow the hot refrigerant gas to bypass the second row (54) of the heat exchanger to the first row (52) of the heat exchanger to better defrost the first row where most of the frost typically accumulates in the tube and fin type of heat exchanger shown (col. 4, lines 45-52). Hayes uses three vertical headers on one side of the heat exchanger (FIG. 1 and col. 3, lines 25-26), which include an intermediate header (70) connected with feeder tubes (64 and 66) to the two rows (52 and 54) of cross tubes of the heat exchanger (50). The intermediate header is connected to each of the other headers (60 and 80) by horizontal cross tubes (rows 52 and 54) that pass through vertical fins (58, FIG. 1) and by feeder tubes (62, 64, 66, and 68). In Hayes, the refrigerant delivered to the second header through solenoid valve 92 and refrigerant conduit (hot gas bypass line) 90, passes through the cross tubes of coil row 52 before reaching header 60 (analogous to the second header of various embodiments herein). Hayes does not teach or suggest passing refrigerant through a header (e.g., 60, 70, or 80) of heat exchanger 50 without also passing that refrigerant through the cross tubes of coil row 52.
In various applications, in the defrost mode, as hot refrigerant gas is delivered to the heat exchanger, a portion of this heat will be transferred to the environment surrounding the heat exchanger. In particular, heat may be transferred via convection to air around the heat exchanger. Heat that is transferred to the air is not available or is less available to defrost the heat exchanger, especially for portions of the heat exchanger that are physically below the location where the heat is transferred to the air. As mentioned, in prior heat pumps, the outdoor air fan was typically turned off during the defrost cycle, which avoids heat loss to the surrounding air through forced convection. Natural convection still occurs, however, under such circumstances, carrying the hot air and heat upward where the heat is lost to the environment. For example, air heated by the heat exchanger can travel upward through the fan, pushed up by buoyancy forces from denser colder air, and colder air tends to flow through the heat exchanger to replace the warm air that has risen. This colder air flowing through the heat exchanger continues to cool the heat exchanger, cooling the refrigerant and taking heat away from the intended purpose of melting the frost. As a result, frost has remained on the heat exchanger, particularly on the lower portion of the heat exchanger, after a defrost cycle is completed, and it has been necessary to extend the defrost cycle and remain in the defrost mode for a longer time in order to defrost a heat exchanger completely or adequately.
Extending the defrost cycle in HVAC applications, for example, is undesirable because the heat pump delivers cold air to the space during the defrost cycle, which may lower the temperature in the space significantly below the thermostat set point temperature, may cause a cold draft and discomfort to the occupants of the space during the defrost mode, may cause the occupants of the space to believe that the heat pump is not working properly, or a combination thereof, for instance. Extension of defrost cycles and less effective defrost cycles may be undesirable in other applications (besides HVAC) as well, among other things, because heating or cooling is unavailable during the defrost cycle and because energy used during the defrost cycle does not contribute to the heating or cooling that is intended to be produced by the heat pump.
As a result, needs or potential for benefit or improvement exist for defrost cycles for heat pumps and methods of defrosting heat exchangers of heat pumps that are more effective, that direct hot refrigerant gas to areas of the heat exchanger that otherwise would not get warm enough, that take less time to complete, that work effectively with microchannel heat exchangers, or a combination thereof, as examples. In addition, needs or potential for benefit or improvement exist for defrost cycles for heat pumps, and methods of defrosting heat exchangers, that reduce the amount of heat loss to the air from the heat exchanger during the defrost cycle, that reduce natural convection during the defrost cycle, or a combination thereof, as examples. Needs and potential for benefit or improvement also exist for heat pumps and methods of defrosting heat exchangers that that are inexpensive, that can be readily manufactured, that are easy to install, that are reliable, that have a long life, that are compact, that are efficient, that can withstand extreme environmental conditions, or a combination thereof, as examples.
Further, needs or potential for benefit or improvement exist for methods of controlling, manufacturing, and distributing such heat pumps, HVAC units, buildings, systems, devices, and apparatuses. Other needs or potential for benefit or improvement may also be described herein or known in the HVAC or heat pump industries. Room for improvement exists over the prior art in these and other areas that may be apparent to a person of ordinary skill in the art having studied this document. | {
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A. Field of the Invention
The present invention relates to a method and device for selecting data symbols to be transmitted in a digital communication system. Although the invention provides a method of signal point mapping and may be applied to any data communication system, it is particularly well suited for use in systems where the selection of constellation points is subject to relatively strict criteria, e.g., where signal points within a constellation are not equally spaced, or where a constellation or constituent sub-constellations may contain a number of points that is not a power of two. The method described herein is also well suited for the case where the number of elements within the constellations varies from symbol to symbol.
Such restrictions are encountered in communication systems that use the public digital telephone network where one side of the communication link (typically a server) has direct digital access to the network. In such a system the constellation selection is limited in part by the presence of Robbed-Bit-Signaling (RBS) and/or a Network Digital Attenuators (NDA), and power constraints imposed by government (e.g., FCC) regulations. These techniques also can be used to help minimize the impact of RBS/NDA on the data rate over such channels.
B. Description of the Related Art
As stated above, the signaling method and device described herein may be used in many types of digital communication systems. Generally, modulation techniques for the transmission of digital information involve modulating the amplitude and phase of a carrier frequency. A baseband signal (an unmodulated information sequence such as a train of pulses of various amplitudes) may be used to modify the amplitude of a carrier frequency sine wave. Because a carrier may also be separated into orthogonal cosine and sine components (also referred to as inphase (I) and quadrature (Q) channels), a modulated carrier may be thought of as the sum of a modulated sine wave and a modulated cosine wave.
As is well known in the art, a two-dimensional plane, or I-Q plane, is used as a shorthand notation to represent the amplitude and phase of the carrier. The signals that make up a signal constellation are represented as points in the I-Q plane, which are usually set out in a grid-like fashion. A particular signal point may be specified as a coordinate pair in the I-Q plane. The points in the I-Q plane arc also generally referred to as a baseband representation of the signal because the points represent the amplitudes by which the sine and cosine components of a carrier will be modified. Each "signal point" is also referred to herein as a "symbol."
While the invention described herein is applicable to systems that use modulated carriers as described above, the preferred embodiments are essentially baseband systems that do not involve the modulation of a carrier. Consequently, the signal points are selected from a single-dimensional signal space, as opposed to a two-dimensional inphase/quadrature signal space. The system for which the invention is particularly well suited uses the public digital telephone network.
1. Digital Telephone Network
For many years the public digital telephone network (DTN) has been used for data transmission between modems. Typically, a modulated carrier is sent over a local loop to a service provider (e.g., a Regional Bell Operating Company), whereupon the service provider quantizes the signal for transmission through the DTN. A service provider that is located near the receiving location converts the digital signal back to an analog signal for transmission over a local loop to the receiving modem. This system is limited in the maximum achievable data rate at least in part by the sampling rate of the quantizers, which is typically 8 kHz (which rate is also the corresponding channel transmission rate, or clock rate, of the DTN).
Furthermore, the analog-to-digital (A/D) and digital-to-analog (D/A) conversions are typically performed in accordance with a non-linear quantizing rule. In North America, this conversion rule is known as .mu.-law. A similar non-linear sampling technique known as A-law is used in certain areas of the world such as Europe. The non-linear A/D and D/A conversion is generally performed by a codec (coder/decoder) device located at the interfaces between the DTN and local loops.
It has been recognized that a data distribution system using the public telephone network can overcome certain aspects of the aforesaid limitations by providing a digital data source connected directly to the DTN, without an intervening codec. In such a system, the telephone network routes digital signals from the data source to a client's local subscriber loop without any intermediary analog facilities, such that the only analog portion of the link from the data source to the client is the client's local loop (plus the associated analog electronics at both ends of the loop). The only codec in the transmission path is the one at the DTN end of the client's subscriber loop.
FIG. 1 shows a block diagram of a data distribution system. The system includes a data source 10, or server, having a direct digital connection 30 to a digital telephone network (DTN) 20. A client 40 is connected to the DTN 30 by a subscriber loop 50 that is typically a two-wire, or twisted-pair, cable. The DTN routes digital signals from the data source 10 to the client's local subscriber loop 50 without any intermediary analog facilities such that the only analog portion of the link from the server 10 to the client 40 is the subscriber loop 50. The analog portion thus includes the channel characteristics of the subscriber loop 50 plus the associated analog electronics at both ends of the subscriber loop 50. The analog electronics are well known to those skilled in the art and typically include a subscriber line interface card at the central office that includes a codec, as well as circuitry used to generate and interpret call progress signals (ring voltage, on-hook and off-hook detection, etc.). In the system of FIG. 1, the only D/A converter in the transmission path from the server 10 to the client 40 is located at the DTN 20 end of the subscriber loop 50. It is understood that the client-side, or subscriber-side, equipment may incorporate an A/D and D/A for its internal signal processing, as is typical of present day modem devices. For the reverse channel, the only A/D converter in the path from the client 40 to the server 10 is also at the DTN 20 end of the subscriber loop 50.
In the system of FIG. 1, the server 10, having direct digital access to the DTN 20 may be a single computer, or may include a communications hub that provides digital access to a number of computers or processing units. Such a hub/server is disclosed in U.S. Pat. No. 5,528,595, issued Jun. 18, 1996, the contents of which is incorporated herein by reference. Another hub/server configuration is disclosed in U.S. Pat. No. 5,577,105, issued Nov. 19, 1996, the contents of which is also incorporated herein by reference.
In the system shown in FIG. 1, digital data can be input to the DTN 20 as 8-bit bytes (octets) at the 8 kHz clock rate of the DTN. This is commonly referred to as a DS-0 signal format. At the interface between the DTN 20 and the subscriber loop 50, the DTN 20 codec converts each byte to one of 255 analog voltage levels (two different octets each represent 0 volts) that are sent over the subscriber loop 50 and received by a decoder at the client's location. The last leg of this system, i.e., the local loop 50 from the network codec to the client 40, may be viewed as a type of baseband data transmission system because no carrier is being modulated in the transmission of the data. The baseband signal set contains the positive and negative voltage pulses output by the codec in response to the binary octets sent over the DTN. The client 40, as shown in FIG. 1, may be referred to herein as a PCM modem.
FIG. 3 shows a .mu.-law to linear conversion graph for one-half of the .mu.-law codeword set used by the DTN 20 codec. As shown in FIG. 3, the analog voltages (shown as decimal equivalents of linear codewords having 16 bits) corresponding to the quantization levels are non-uniformly spaced and follow a generally logarithmic curve. In other words, the increment in the analog voltage level produced from one codeword to the next is not linear, but depends on the mapping as shown in FIG. 3. Note that the vertical scale of FIG. 3 is calibrated in integers from 0 to 32,124. These numbers correspond to a linear 16-bit A/D converter. As is known to those of ordinary skill in the art, the sixteenth bit is a sign bit which provides integers from 0 to -32124 which correspond to octets from 0 to 127, not shown in FIG. 3. Thus FIG. 3 can be viewed as a conversion between the logarithmic binary data and the corresponding linear 16-bit binary data. It can also be seen in FIG. 3 that the logarithmic function of the standard conversion format is approximated by a series of 8 linear segments.
The conversion from octet to analog voltage is well known, and as stated above, is based on a system called .mu.-law coding in North America and A-law coding in Europe. Theoretically, there are 256 points represented by the 256 possible octets, or .mu.-law codewords. The format of the .mu.-law codewords is shown in FIG. 4, where the most significant bit b.sub.7 indicates the sign, the three bits b.sub.6 -b.sub.4 represent the linear segment, and the four bits, b.sub.0 -b.sub.3 indicate the step along the particular linear segment. These points are symmetric about zero; i.e., there are 128 positive and 128 negative levels, including two encodings of zero. Since there are 254 non-zero points, the maximum number of bits that can be sent per signaling interval (symbol) is just under 8 bits. A .mu.-law or A-law codeword may be referred to herein as a PCM codeword. It is actually the PCM codeword that results in the DTN 20 codec to output a particular analog voltage. The codeword and the corresponding voltage may be referred to herein as "points."
Other factors, such as robbed-bit signaling, digital attenuation (pads), channel distortion and noise introduced by the subscriber loop, and the crowding of points at the smaller voltage amplitudes and the associated difficulty in distinguishing between them at the decoder/receiver, may reduce the maximum attainable bit rate. Robbed Bit Signaling (RBS) involves the periodic use of the least significant bit (LSB) of the PCM codeword by the DTN 20 to convey control information. Usually the robbed bit is replaced with a logical `1` before transmission to the client 40. In addition, due to the fact that a channel might traverse several digital networks before arriving at the terminus of the DTN 20, more than one PCM codeword per 6 time slots could have a bit robbed by each network, with each network link robbing a different 1 sb.
To control power levels, some networks impose digital attenuators that act on the PCM codewords to convert them to smaller values. Unlike most analog attenuators, a network digital attenuator (NDA) is not linear. Because there are a finite number of digital levels to choose from, the NDA will be unable to divide each codeword in half. This causes distortion of the analog level ultimately transmitted by the codec over the subscriber loop 50. RBS and an NDA can coexist in many combinations. For example, a PCM interval could have a robbed bit of type `1`, followed by an NDA followed by another robbed bit of type `1`. This could happen to a byte if a channel goes through a bit-robbed link, then through an NDA, then another bit-robbed link before reaching the DTN 20 codec.
It is evident that the above-described data transmission system imposes many constraints on the points that may be used to form a signal constellation. Inter alia, the octets will always be converted to non-linearly spaced voltage pulses in accordance with .mu.-law or A-law conversion; 1 sbs may be robbed during some time slots making some points unavailable in that time slot; digital attenuators may make some points ambiguous; and noise on the local loop may prevent the use of closely spaced points for a desired error rate.
2. Shell Mapping
Shell mapping is a prior art technique of assigning transmit data bits to constellation points, or symbols. Shell mapping requires that an encoder group symbols together in mapping frames, typically consisting of eight symbols. The constellation is divided into a set of rings that are generally concentric, with an equal number of points per ring. A block of transmit data bits is then used to select a sequence of ring indices and to select the points to send from each of the selected rings.
For purposes of determining the most desirable sequence of rings to select, each ring is assigned a cost value associated with its distance from the origin. The costs are generally representative of the power needed to transmit a point from within that ring. For each possible sequence of rings, a total cost is calculated. The ring index selector/encoder is designed to prefer the least-cost ring sequences, i.e., low-powered point sequences are preferred over high-power point sequences. Note that the above scheme of eliminating certain ring sequences is only possible when there is signal set redundancy. This requires the constellations to be larger than would otherwise be required in systems that do not utilize shell mapping. Furthermore, because the excluded ring sequences are those that include large numbers of outer rings and the favored ring sequences are those that include large numbers of inner rings, the transmitted constellation points will have a non-equi-probable distribution. As a result, the shell mapping technique tends to reduce average power for a given spacing between points (called d.sub.min), thereby increasing the peak-to-average power ratio (PAR).
The reduction in average power (compared to an equi-probable point distribution) can be exploited in an average power constrained system by increasing the distance between points until the average power is equal to an equivalent system with equi-probable point distribution. The receiver sees points with improved d.sub.min that are easier to detect in the presence of noise. Generally, the possible improvement is less than 2.0 dB, and the practically realizable benefit is about 0.5 to 1.0 dB.
The advantage of shell mapping applies to a system where the points are equally distributed within the signal space. This means that the spacing between points in the center of the constellation is the same as the spacing between points at the outer edge. This is not the case in PCM modems where the constellation points are inherently unequally spaced. There is a strong incentive to minimize constellation size in such a scenario. As shown in FIG. 3, the codes in a PCM codec are arranged in segments of 16 members each, with each higher amplitude segment having twice the spacing of the next lower segment. Constellation expansion involves adding more low-power points that are spaced closer together than high-power points. In some cases, the addition of a single point can reduce minimum spacing dramatically. Thus the idea of expanding the constellation to achieve better d.sub.min in may have the opposite effect, and reduce it.
It is clear that shell mapping has disadvantages when utilized in a system having constraints on signal point selection that are inherent in PCM modems. Described herein is an improved shell mapping method that includes the features of Multiple Modulus Conversion to obtain an effective signal mapping technique. | {
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1. Field of the Invention
The present invention relates to a seedling transfer tools and more particularly pertains to handling seedlings in a tender and convenient manner.
2. Description of the Prior Art
The use of apparatus for handling seedlings of various designs and configurations is known in the prior art. More specifically, apparatus for handling seedlings of various designs and configurations heretofore devised and utilized for the purpose of transporting seedlings through various methods and apparatuses are known to consist basically of familiar, expected, and obvious structural configurations, notwithstanding the myriad of designs encompassed by the crowded prior art which has been developed for the fulfillment of countless objectives and requirements.
By way of example, U.S. Pat. No. 5,040,471 to Lamont, Jr. discloses a Hand Vegetable Transplanter With Assembly for Varying Quantity of Liquid Dispensed. U.S. Pat. No. 3,865,055 to Gilbaugh discloses a Plant Transplanter. U.S. Pat. No. 3,210,112 to Glynn discloses a Garden Tool. U.S. Pat. No. 3,596,966 to Shredl discloses a Weeder. U.S. Pat. No. 3,594,931 to Yost discloses an Apparatus for Excavating Plants. Lastly, U.S. Pat. No. 5,398,624 to Caron discloses a Transplanting Tool.
In this respect, the seedling transfer tools according to the present invention substantially departs from the conventional concepts and designs of the prior art, and in doing so provides an apparatus primarily developed for the purpose of handling seedlings in a tender and convenient manner.
Therefore, it can be appreciated that there exists a continuing need for a new and improved seed transporting system which can be used for handling seedlings in a tender and convenient manner. In this regard, the present invention substantially fulfills this need. | {
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1. Field of the Invention
This invention relates to the art of tooth maintenance for large animals and more particularly to a set of tools which may be used under powered motion for care and maintenance such as removing a selected portion of the exposed surface of teeth, such as equine teeth, with the powered hand being guided into the mouth of the horse. The powered tool is partially guarded so as to protect fleshy portions of the horse's mouth from being engaged by the powered tool. The tool may have a rotary cutting surface of a selected size and shape, sometimes commonly called a burr, or the tool may be a rotary cut-off disk. The selected tool, either the burr or cut-off disk, is supported and partially enclosed in a protective guard formed as a hand piece that may be guided into the mouth of a horse to perform care and maintenance on a selected portion of the teeth. The hand piece fabricated according to the teaching of this invention provides for quick on and off attachment of a selected cutting surface for maintenance of a preselected portion of teeth within the same hand piece or another hand piece sized to ease access to the next selected portion of the horse's mouth. The selected cutting surface is mounted within the protective guard/hand piece arrangement that may further incorporate a vacuum channel whereby the tooth dust and debris created by the powered cutting surface removing a portion of tooth is sucked out of the mouth of the horse. The motion of the tooth surface removal tool may be changed from rotary to powered reciprocating motion for a selected portion of the teeth. Attaching the powered drive to the rotary cutting surface by means of an adjustable clutch further enhances protection from injury to the inside of the mouth of the horse.
2. Description of the Prior Art
Throughout the life of the horse, the teeth continue to extend from the gums. When non-domesticated horses graze on the ground, they pick up sand and hard particles in the grass, which would naturally reduce the growth of the horse's teeth.
In order for domesticated horses to properly chew their food, which consists mostly of preprocessed grain and formula, the teeth require periodic maintenance. Without the natural wearing of the teeth from grazing on the ground, the teeth may grow uneven and too long, thus interfering with normal eating.
In the past, regular dental care to remove points, hooks or ridges that have grown or worn into the teeth required the use of a specially designed rasp-like tool to remove them, a process called floating the teeth. Because of the structure of the teeth, the horse does not have nerves extending upward in the teeth and therefore feels no pain when the teeth are filed to reshape them.
A grown horse uses 36 teeth to eat. The 6 upper incisors and the 6 lower incisors are for shearing grass and leaves, which are masticated by 12 premolars, and 12 molars located on both sides of the upper and lower jaws. These molars must align for the horse to chew properly.
The majority of dental problems are associated with the molars and premolars. However, if the incisors are to long, opposing molars and premolars may be prevented from engaging properly.
In the prior art, hand tools similar to metal files or rasps were used to remove a selected portion of the tooth surface. These tools consisted of several shaped handles with pads mounted on one end. The pads accepted plates having an abrasive or specially designed file or rasp-toothed surface selected by the user. The mounted abrasive or rasp on the handle was then inserted into the horse's mouth and positioned against the tooth structure that needed to be altered. The user then manually applied pressure and movement to the handle until the selected portion of the tooth structure was removed.
Some prior solutions to the problem were to add motor power to the burrs to provide a “power dental tool” to replace the manual rasps. These solutions ease the manual work but introduced other problems such as the uncontrolled creation of dust and debris as well as the danger of injury to the horse and user from exposed high speed reciprocating or rotary burrs or rasps which may engage soft tissue such as the cheek, tongue, or gums inside the horses mouth.
Thus, there has long been a need for an arrangement that allows the user, usually a veterinarian, an owner or an equine dentist, to easily perform the removal of preselected material from the exposed surface of the horse's teeth without danger to the horse or the person doing the job.
It is desired that the arrangement allow the user to access the full array of teeth with a set of preselected shaped and surfaced files, rasps or other tools such as diamond cut-off blades.
It is further desired that the arrangement be motor driven but provide safety to the user and horse.
It is further desired to provide preselected shaped covers or guards around selected portions of the rotary tool to allow the system to be used in all parts of the mouth of the horse.
It is further desired to provide a clutch between the motor and the rotary tool. The threshold of disengagement of the rotary power applied by means of the clutch may be adjustable with access for adjustment that does not require dismantling the system.
It is further desired that the arrangement be able to remove accumulation of debris from the inside of the horse's mouth during the procedure.
It is desired that a simple latching or unlatching movement engage and disengage the selected tool within the rotary driven arrangement.
It is desired that a simple latching or unlatching movement engage and disengage selected guards around the rotary tool.
It is further desired that during the operation of the arrangement for the removal of material from inside the mouth the inadvertent engagement of soft tissue inside the mouth not adversely affect the user or the horse.
It is desired that reconfiguration of the arrangement be accomplished even if the users hands are slippery.
It is further desired that the motor be separated from the rotary tool by a drive train so that the user need not support the weight of the motor during the procedure.
It is further desired that the arrangement be easily adapted to a “power dental tool” motor or handle the user may presently own. | {
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The invention relates to a central release device for a hydraulic clutch actuation system. The invention relates in particular to a central release device of a hydraulic clutch actuation system for a motor vehicle clutch.
A conventional hydraulic clutch actuation system for motor vehicles has a master cylinder which is connected to a compensating reservoir filled with hydraulic fluid and which can be actuated via a clutch pedal. The master cylinder is hydraulically connected via a pressure line to a slave cylinder, so that the pressure produced in the master cylinder by depressing the clutch pedal can be transmitted to the slave cylinder via the fluid column in the pressure line. The release bearing of the clutch is as a result subjected by the slave cylinder to an actuating force in order to separate the clutch pressure plate from the clutch driving disc and thus the engine from the transmission of the motor vehicle.
In order to guarantee smooth clutch actuation with a small space requirement for the slave cylinder, the prior art has proposed forming the slave cylinder as an annular cylinder which is disposed around the clutch or transmission shaft and attached to the transmission. An annular piston is disposed in sliding fashion in the axial direction of the clutch or gear shaft in the annular cylinder and is connected for operation to the release bearing of the clutch. When the annular cylinder is acted upon hydraulically via the pressure line, the annular piston acts via the release bearing on the release lever of the clutch in order to release the latter. Because they are disposed concentrically with the clutch or transmission shaft, slave cylinders of this kind are also called central release devices.
The prior art is not lacking in proposals as to how such central release devices should be formed (e.g. EP 0 095 841 B1, EP 0 168 932 B1, DE 41 09 125 A1, DE 43 13 346 A1, DE 197 42 468 A1). A feature common to the central release devices considered here is the fact that they have a housing which comprises a through-bore, is cut out of a metallic material or injection moulded from a plastics material and can be attached to a transmission wall in the motor vehicle. A drawn steel sleeve is provided coaxially with the housing in the bore, this sleeve comprising at the end a flange which extends in the radial direction and is disposed between the housing and the transmission wall when the central release device is in the mounted state. In this prior art the inner circumferential face of the bore defines, together with the radial flange and the outer circumferential face of the steel sleeve, the pressure chamber containing the annular piston which is guided on the steel sleeve and provided with a sealing element.
In order to seal off the pressure chamber, an elastomeric sealing ring is generally provided between the housing and the flange of the steel sleeve. The steel sleeve is also connected in a fixed fashion at its flange to the housing by means of a screwed connection (EP 0 095 841 B1), by caulking the housing (EP 0 168 932 B1), by means of a retaining ring (DE 41 09 125 A1), by a welded joint, riveting, through-fitting or a rolling connection (DE 43 13 346 A1) or by means of a snap connection (DE 197 42 468 A1), so that the sealing ring between the housing and the flange of the steel sleeve and the sealing element at the annular piston are not accessible and therefore cannot be damaged. However this prior art has the disadvantage of entailing a high expenditure to form the connection between the housing and the flange of the steel sleeve, and this constitutes a significant proportion of the production costs of this mass-produced article.
As compared with the prior art according to EP 0 168 932 B1, which constitutes the type in question, the object of the invention is therefore to provide a simply formed central release device which can be produced more conveniently without the risk of functional problems.
This object is solved by central release device for a hydraulic clutch actuation system, with a housing and a sleeve provided with a flange, which together define a pressure chamber for accommodating an annular piston, by means of which a release bearing guided on the sleeve can be displaced, wherein a spring, which braces the housing and the release bearing apart, subjects the housing to a force directed at the flange, and a seal is provided between the housing and the flange to seal off the pressure chamber, wherein there is a retaining element, which can be detached to operate the central release device and which, when the central release device is in the non-mounted state, forms a stop for the housing and prevents the housing alone from moving against the force of the spring away from the flange of the sleeve beyond a predetermined amount.
According to the invention, given a central release device for a hydraulic clutch actuation system which comprises a housing and a sleeve provided with a flange, which together define a pressure chamber for accommodating an annular piston, by means of which a release bearing guided on the sleeve can be displaced, wherein a spring, which braces the housing and the release bearing apart, subjects the housing to a force directed at the flange, and a seal is disposed between the housing and the flange to seal off the pressure chamber, a retaining element, which can be detached to operate the central release device, is provided which, when the central release device is in the non-mounted state, forms a stop for the housing and prevents the housing alone from moving against the force of the spring away from the flange of the sleeve beyond a predetermined amount.
In other words, there is no fixed connection between the housing of the central release device and the sleeve, so that the production of the central release device is simplified overall. In this respect the invention utilises the knowledge that the systems known from the prior art for attaching the sleeve to the housing are only actually required until the central release device is mounted in the housing, as when the central release device is in the mounted state the flange of the sleeve is secured on one side between the housing of the central release device and on the other side a housing wall or a housing cover of the transmission, to which the housing of the central release device is attached, e.g. by means of screws. The detachable retaining element is provided according to the invention for the purpose of packing, storing, transporting and mounting the central release device, which element, being assisted by the claimed securement of the housing in relation to the flange of the sleeve, preventsxe2x80x94via the spring already provided in the prior art for reasons relating to function and noisexe2x80x94the seal between the housing and the flange of the steel sleeve or the sealing element at the annular piston from being accessible and in this connection damaged, which could result in leakages during operation of the central release device. The retaining element, which is to be detached to operate the central release device after it has been mounted in the motor vehicle, can advantageously be reused or is repeatedly reusable. A further advantage lies in the fact that the seal between the housing and the flange of the sleeve can easily be replaced should this appear necessary on account of material ageing, for example.
Preferably, the housing is expediently provided at its end face which is turned towards the flange of the sleeve or the flange of the sleeve is provided at its end face which is turned towards the housing with an annular groove which accommodates the seal, the thickness of which is greater in the non-deformed state than the depth of the annular groove, wherein the predetermined amount by which the housing can move away from the flange of the sleeve when the central release device is in the non-mounted state is less than or equal to the depth of the annular groove. Therefore, when the central release device is handled outside of the vehicle as mentioned, the retaining element reliably prevents the seal from sliding out of its predetermined position and being damaged between the end face of the housing and the end face, lying opposite this, at the flange of the sleeve.
There are various preferred arrangement variants for the retaining element, in which the release bearing is in each case guided on the sleeve by a sliding sleeve, which is held at the sleeve by means of a stop, and the retaining element is formed as a cross slide. According to claim 3, this cross slide can advantageously be secured positively and non-positively at the sleeve in an annular gap between the sliding sleeve and the housing. The cross slide may alternatively be secured positively and non-positively at the sliding sleeve in a groove made in the outer circumference of the sliding sleeve or at an offset made at the outer circumference of the sliding sleeve. This arrangement variant relates to central release devices in which the sliding sleeve always, i.e. even in the completely withdrawn state when lying against the stop of the sleeve, engages in the annular gap between the housing and the sleeve with its end which is turned towards the flange of the sleeve (see, e.g. EP 0 168 932 B1). According to a further alternative, the cross slide may be secured positively and non-positively at the housing in a groove made in the outer circumference of the housing or at an offset made at the outer circumference of the housing and comprises a stop face for a protective sleeve which is attached to the sliding sleeve and surrounds the housing telescopically, as known, for example, from EP 0 095 841 B1, or for an abutment, attached to the sliding sleeve, for the spring.
Preferably, the cross slide expediently comprises a handle part from which two arms extend which, viewed in a plan view, essentially form a C shape. In order to improve handling of the cross slide, the handle faces of the handle part may each be provided with a profile.
The arms of the cross slide can spring out elastically and comprise a part-cylindrical inner circumferential face, wherein the clearance between the arm ends is slightly smaller than the diameter of the part-cylindrical inner circumferential face, so that, depending on the arrangement variant, the cross slide engages behind the sleeve, the sliding sleeve or the housing like a snap connection in the mounted state. As a result, the cross slide is advantageously prevented, in a simple manner, from unintentionally separating from the central release device.
Preferably, the arm ends are provided at the sides which are turned towards one another with a respective fitting bevel, which makes it easier to fit the cross slide to the central release device.
The securing element or cross slide can be produced particularly easily and inexpensively if it consists of a plastics material. Finally, preferably, the housing of the central release device advantageously consists of a plastics material, while the sleeve is made of steel. | {
"pile_set_name": "USPTO Backgrounds"
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Given a user query, an information retrieval (IR) system, for example a search engine, produces a ranked list of results that are most likely to satisfy a users needs and in the example of a search engine, the results may be web pages or images. In another example, the IR system may be an online shopping service and in this case the results may be suggestions of other items to buy based on a single purchase made by a user, or the IR system may be an online advertising system where the results are the advertisements displayed to a user.
To improve the relevance of the results provided, an IR system may tailor results based on the preferences of other users. For example in online shopping a user may be told ‘users who bought X also bought Y’. In search applications, users may re-rank the results (or the revised rank may be inferred based on whether a user clicks on a particular link or not) and this information may be used to improve results provided to other users. There are, however, security considerations with this sharing of data. In particular, the privacy of a user (i.e. ensuring that other users do not learn about a user's exact search patterns or retrieved documents) and the quality of the shared data (i.e. ensuring that the system cannot be overly influenced by a user that maliciously injects information to manipulate the results provided).
Some IR systems use social networks to create a personalized social search which determines the ranking of documents based on the preferences within a group of friends. An example method of personalized social search allows users to designate search mates with whom they share their search preferences. Privacy is maintained by enabling a user to specify who can see their preference data and further privacy features can be provided through the ability to perform private searches, delete previous searches or through enabling opting-in or opting-out of personalized searching.
The embodiments described below are not limited to implementations which solve any or all of the disadvantages of known preference propagation systems. | {
"pile_set_name": "USPTO Backgrounds"
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1. Field of the Invention
The present invention relates to electostatographic copying and printing machines of the type having electronic imaging, and more particularly to improving the quality of images such machines produce by automatically adjusting process control parameters.
2. Description of the Prior Art
In electrostatographic machines such as printers and copiers, image contrast, density, and color balance can be adjusted by changing certain process control parameters. Such process control parameters most frequently include initial charge V.sub.0, exposure E.sub.0, and developer bias voltage V.sub.bias. Other process control parameters which are less frequently used, but which are effective to control the copy contrast, density, and color balance include the concentration of toner in the developer mixture and the image transfer potential.
The existing techniques for regulation of electrostatographic machine process control parameters are either very expensive or user-unfriendly. For example, a test patch or patches may be formed and developed on non-image areas of an image transfer member. The resulting toner densities of the patches are used to control at least some of the process control parameters, but such a system is expensive to build.
Another technique involves operator-adjustable knobs for setting process control parameters. Although less expensive, this technique involves an iterative operator adjustment of several variables, and usually requires multiple test runs. Since the process control parameters are interrelated, their proper adjustment by an operator would require considerable skill and judgement on his or her part. | {
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In some prior art tool bodies, strain gauges are installed for getting the twisting forces applied to the tool body. However generally, theses strain gauges have no sufficient sensitivities for providing a precise twisting force value. Thereby it will cause that the tool body with precise control cannot be used.
In one improvement, the tool body is formed with a round recess and the strain gauge is installed in the recess. However since the recess has a round shape and the strain gauge is installed at a center of the recess, but is operation, the stresses of the tool body are concentrated on the lateral wall of the recess and thus as a result, the deformation of the strain gauge is smaller and thus it cannot provide a precise value about the measured twisting force. Thereby this way can be effectively increase the sensitivity of the strain gauge.
In another improvement, U.S. Pat. No. 4,006,629, two sides of a handle tool are formed with grooves and four strain gauges are installed in the grooves. However in the patent, a conductive wire for a display of the handle tool is exposed out. It is easy to be collided or broken so as to make the strain gauges cannot work. Thereby the structure is complicated and four strain gauges are used. These all increase the cost of the handle tool. | {
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Embodiments of the invention relate to file systems, and in particular, to a switch-aware parallel file system.
A file system is a management structure for storing and organizing files and data. File systems are software components that use storage subsystems to maintain files and data. File systems impose a logical structure on a storage subsystem to allow client computers to create, store, and access data on the storage subsystem. A Distributed File System is a file system that supports sharing of files and storage resources for multiple clients over a network. An Internet-Scale File System is a distributed file system designed to run on low-cost commodity hardware, which is suitable for applications with large data sets. A cluster file system is a type of distributed file system that allows multiple compute nodes in a computing cluster to simultaneously access the same data stored within the computing cluster. A parallel file system is a type of distributed file system that distributes file system data across multiple servers and provides for concurrent access for multiple tasks of a parallel application.
A computing cluster includes multiple systems that interact with each other to provide client systems with data, applications, and other system resources as a single entity. Computing clusters typically have a file system manage data storage within the computing cluster. Computing clusters increases scalability by allowing servers and shared storage devices to be incrementally added. Computing clusters use redundancy to increase system availability and withstand hardware failures.
Supercomputers (e.g., IBM General Parallel File System) use parallel file systems to transfer large amounts of data at high speeds, which reduces a likelihood of any one storage node becoming a performance bottleneck. However, uses of supercomputers in commodity data centers are limited because data striping creates a many-to-many architecture of storage nodes to compute nodes, which requires expensive networking hardware to achieve acceptable performance.
Performance bottlenecks would arise in modern data centers that use smaller commodity switches, if parallel file systems were used. Commodity switches lack sufficient buffer space for each port, which causes packets to be dropped if too many packets are directed towards a single port. Commodity switches also have a limited number of ports, necessitating a hierarchy of switches between compute nodes and storage nodes. Consequently, more nodes must share a decreasing amount of available bandwidth to the parallel file system with each successive level in the hierarchy.
Cheaper commodity-based computing clusters do not match performance of supercomputers due to inherent limitations of low-end hardware. Cloud computing and software frameworks (e.g. MapReduce) for processing and generating large data sets enable use of inexpensive commodity-based computing clusters in data centers. Many data center use internet-scale file systems that rely on co-locating compute processing and required data. The internet-scale file systems avoid bottlenecks created by parallel file systems by striping data in very large chunks (e.g. 64 MB), directly on compute nodes with each job performing local data access. However, compute and data co-located creates other limitations in system architecture. For example, data needs to be replicated on multiple nodes to prevent data loss and alleviate I/O bottlenecks, which increase availability and integrity while proportionally reducing available disk space. In addition, general or traditional applications cannot utilize these file systems because of their lack of Portable Operating System Interface for Unix (POSIX) support and data sharing semantics and their limited support for remote data access using Network File System (NFS) or Common Internet File System (CIFS) protocols.
Typical data centers use multi-tier trees of network switches to create computing clusters. Servers are connected directly into a lower tier consisting of smaller switches with an upper tier that aggregates the lower tier. The network infrastructure will be oversubscribed by using large switches in the upper tiers. The oversubscription is due to cost limitations for typical data centers. Accordingly, the oversubscription creates inter-switch bottleneck that constrains data access in data centers. | {
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Modern electronic devices such as a notebook computer comprise a variety of memories to store information. Memory circuits include two major categories. One is volatile memories; the other is non-volatile memories. Volatile memories include random access memory (RAM), which can be further divided into two sub-categories, static random access memory (SRAM) and dynamic random access memory (DRAM). Both SRAM and DRAM are volatile because they will lose the information they store when they are not powered. On the other hand, non-volatile memories can keep data stored on them. Non-volatile memories include a variety of sub-categories, such as read-only-memory (ROM), electrically erasable programmable read-only memory (EEPROM) and flash memory.
ROM is a type of solid state memory. Each ROM cell is fabricated with a desired logic state. In other words, a bit of binary data is permanently stored in a ROM cell either in a logic state of “0” or “1” depending on whether there is a conductive path between a bit line and a VSS line. In accordance with a definition of a ROM cell's logic, when a logic state of “1” is stored in a ROM cell, there is a connected path from a bit line to a VSS line. On the other hand, when a logic state of “0” is stored in a ROM cell, there is no connected path from the bit line to the VSS line. The definition of “0” and “1” described above can be swapped depending on different applications.
As technologies evolve, semiconductor process nodes have been scaled down for high density ROM integrated circuits. As a result, the form factor of ROM integrated circuit has been improved from shrinking the semiconductor process node (e.g., shrink the process node towards the sub-20 nm node). As semiconductor devices are scaled down, new techniques are needed to maintain the electronic components' performance from one generation to the next. For example, low leakage current transistors are desirable for high density and high speed ROM integrated circuits.
Fin field-effect transistors (FinFETs) have emerged as an effective alternative to further reduce leakage current in semiconductor devices. In contrast to the prior planar MOS transistor, which has a channel formed at the surface of a semiconductor substrate, a FinFET has a three dimensional channel region. In a FinFET, an active region including the drain, the channel region and the source protrudes up from the surface of the semiconductor substrate upon which the FinFET is located. The active region of the FinFET, like a fin, is rectangular in shape from a cross section view. In addition, the gate structure of the FinFET wraps the active region around three sides like an upside-down U. As a result, the gate structure's control of the channel has become stronger. The short channel leakage effect of conventional planar transistors has been reduced. As such, when the FinFET is turned off, the gate structure can better control the channel so as to reduce leakage current.
The three-dimensional shape of the FinFET channel region allows for an increased gate width without increased silicon area even as the overall scale of the devices is reduced with semiconductor process scaling, and in conjunction with a reduced gate length, providing a reasonable channel width characteristic at a low silicon area cost.
Corresponding numerals and symbols in the different figures generally refer to corresponding parts unless otherwise indicated. The figures are drawn to clearly illustrate the relevant aspects of the various embodiments and are not necessarily drawn to scale. | {
"pile_set_name": "USPTO Backgrounds"
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1. Field of the Invention
The present invention relates to a button telephone apparatus (key-system) and an Internet communication system, in particular, those that bidirectionally exchange telephone audio packets between a conventional Internet network (in a narrow sense) and a button telephone apparatus (key-system) through a public telephone network corresponding to the ISDN (Integrated Services Digital network).
2. Description of the Related Art
Conventionally, from a view point of low cost of a long distance communication, as an audio communication network, a system using an Internet network has been developed.
Internet networks are roughly categorized as an Internet network in a broad sense and an Internet network in a narrow sense. In the former Internet network, various networks are connected regardless of their modes. On the other hand, in the later Internet network, with a source of ARPT (Advanced Research Projects Agency) NET, IP (Internet Protocol) is used as a common protocol. The above-described Internet network is categorized as the latter (namely, an Internet network in a narrow sense).
As a first related art reference of an audio communication system using the latter type Internet network, a technology of a service provider that provides the user with a connection service to an Internet network is disclosed as Japanese Patent Laid-Open Publication No. 10-98548. In the first related art reference, the delay time of transmission/reception packets in the Internet network is measured by comparing the transmission time of the packets with the reception time thereof. When the delay exceeds a predetermined time period (in other words, if a call cannot be transmitted through the Internet network due to congestion), as a user service, the service provider informs the user of a message that represents xe2x80x9cSERVICE IS CURRENTLY NOT AVAILABLExe2x80x9d.
As a second related art reference disclosed as Japanese Patent Laid-Open Publication No. 10-164129, a delay time is detected in a similar manner as the first related art reference (Japanese Patent Laid-Open Publication No. 10-98548). In the second related art reference, corresponding to the amount of the delay time, part of received packets are deleted.
In the above-described audio communication system, only the Internet network is used as a communication medium.
In other words, in such related art references, a structure of which the Internet network is used as a new communication network along with the conventional telephone exchange network is not used.
Thus, countermeasures against congestion of the Internet network are required. When the Internet network is used, depending on the congestion thereof, packets cannot be transmitted and received. Alternatively, the data quality of a call may remarkably deteriorate.
Although the above-described related art references disclosed as Japanese Patent Laid-Open Publications Nos. 10-98548 and 10-164129 are technologies against such countermeasures, they do not provide substantial solutions against deterioration of communication environment due to congestion of the network.
In other words, if the user should make an urgent call, the technology of the first related art reference disclosed as Japanese Patent Laid-Open Publication No. 10-98548 does not satisfy the user""s needs. In addition, when the user hears a message xe2x80x9cSERVICE IS CURRENTLY NOT AVAILABLExe2x80x9d, he or she cannot know the thing to do next.
In the second related art reference disclosed as Japanese Patent Laid-Open Publication No. 10-164129, since part of audio data of the user is discarded. In this case, an important part of the audio data may be lost. In other words, the system cannot determine which of part of data is important for the user.
Thus, it cannot be said that such related art references provide the user with sufficient services. In other words, low cost communication has tradeoffs of urgent communication request and important data. Consequently, the user cannot be satisfied with such a service.
To solve such a problem, according to the present invention, a conventional telephone exchange network is still used. In addition, the Internet network can be selectively used. When audio data should be transmitted on real time basis, if it cannot be transmitted through the Internet network, the conventional telephone exchange network that has a stable communication quality is used. Thus, the user""s convenience can be consistent with high quality of data communication.
The present invention is made from the above-described point of view. An object of the present invention is to provide an Internet communication system that allows audio data to be securely to be received and transmitted without a fluctuation of data quality depending on a time zone.
A first aspect of the present invention is an Internet communication system, comprising a plurality of ISDN (Integrated Services Digital network) lines, an Internet network connected to said ISDN lines using IP (Internet Protocol) as a common protocol, at least one button telephone apparatus connected to said ISDN lines, and at least one telephone unit connected to said button telephone apparatus, wherein said button telephone apparatus has a selecting means for selecting a conventional telephone function or an Internet telephone function, wherein when the selecting means selects the Internet telephone function, said button telephone apparatus converts dial data received from said telephone unit into an IP address, the dial data representing a call destination, converts data of the audio signal received from said telephone unit into IP packets, and transmits the IP packets to said Internet network, and wherein when said button telephone apparatus determines that said Internet network of the call destination is in a congestion state, the selecting means selects the conventional telephone function and re-transmits the audio data received from said telephone unit to the same call destination.
A second aspect of the present invention is a button telephone apparatus, connected to at least one telephone unit, for communicating with a plurality of ISDN (Integrated Services Digital network) lines and with an Internet network connected to the ISDN lines with IP (Internet Protocol) as a common protocol, comprising selecting means for selecting a conventional telephone function or an Internet telephone function, wherein when said selecting means selects the Internet telephone function, said button telephone apparatus converts dial data received from said telephone unit into an IP address, the dial data representing a call destination, converts data of the audio signal received from said telephone unit into IP packets, and transmits the IP packets to said Internet network, and wherein when said button telephone apparatus determines that said Internet network of the call destination is in a congestion state, said selecting means selects the conventional telephone function and re-transmits the audio data received from said telephone unit to the same call destination.
In other words, according to the present invention, the button telephone apparatus has two functions that are a conventional telephone function and an Internet telephone function. The user can selectively use one of these functions. When the user uses the Internet telephone function, the apparatus detects the delay of transmitted packets so as to determine whether or not the Internet network congests. When the congestion state of the Internet network exceeds a predetermined level, the apparatus automatically switches the Internet network to a ISDN line exchange network. Corresponding to dial data that was used for the Internet network, the call is re-dialed to the line exchange network. Thus, the audio data of the user can be automatically re-originated. | {
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The present application relates generally to the field of child strollers. More particularly, the present invention relates to a foldable stroller having an adjustable leg support extension that is pivotally secured to the stroller and a mechanism that retains the last adjustment support extension position when the stroller is moved between folded and unfolded conditions.
Foldable strollers are well known in the art, including many designed to be easily and conveniently operated. Foldable strollers having adjustable calf support extensions are also well known in the art. Most such calf support extensions employ a ratchet mechanism that returns to an initial position when the stroller is moved from an unfolded to a folded condition and requires adjustment by the user after the stroller is returned to the unfolded condition. In current designs, the calf support arms are forced upward by the bottom frame during folding. The support arms are able to rotate upward since the ratcheting teeth are ramped to allow rotation in one direction. However, the ratcheting teeth prevent the support arms from moving downward to a desired position after the stroller is unfolded, hence the calf support arms stay in the up position every time the stroller is opened and remain there until manually repositioned by a user.
There is a need for a foldable stroller having an adjustable calf support extension that retains the last adjustment position when the stroller is moved between a folded and unfolded condition to eliminate the extra calf support extension adjustment step following each unfolding. | {
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The present invention relates to a laser control apparatus, more particularly, an apparatus which carries out power control of a semiconductor laser employed for an optical recording/reproducing apparatus, and can control the optical power stably even when an output light is modulated at high speed at the high-speed recording.
A semiconductor laser is generally employed as an optical pick up and the like in an optical recording/reproducing apparatus such as a CD player, a writable CD-R drive, an erasable CD-RW drive and the like. The power of a semiconductor laser varies greatly in accordance with a temperature change or changes with passage of time(lifetime), and therefore, it is necessary to carry out power control for stabilizing the power when employing a semiconductor laser as a light source in an apparatus for performing recording/reproduction into/from an optical recording medium such as an optical disk and the like.
Such prior art semiconductor laser power control apparatus is disclosed in Japanese Published Patent Application No. Hei. 1-204224 in detail.
FIG. 9 is a block diagram for illustrating a prior art semiconductor laser power control apparatus. In figure, numeral 10 denotes a semiconductor laser for radiating laser light to an optical disk; numeral 1 denotes a photodiode for receiving the irradiation light of the semiconductor laser 10; numeral 2 denotes a monitor circuit for monitoring the output of the photodiode 1; numeral 20 denotes a bottom hold circuit for holding a bottom level of the output from the monitor circuit 2; numeral 21 denotes a sample-hold circuit for sample-holding the output from the monitor circuit 2; numeral 22 denotes a peak hold circuit for holding a peak level of the output from the monitor circuit 2; numeral 19 denotes a control circuit for outputting a first, a second and a third digital signals corresponding to a bias reference voltage, an erase power reference voltage and a peak power reference voltage, respectively; numeral 26 denotes a D/A converter for converting the first digital signal outputted by the control circuit 19 to a bias reference voltage; numeral 27 denotes a D/A converter for converting the second digital signal outputted by the control circuit 19 to an erase reference voltage; numeral 28 denotes a D/A converter for converting the third digital signal outputted by the control circuit 19 to a peak power reference voltage; numeral 23 denotes a servo amplifier for comparing the bias reference voltage outputted by the D/A converter 26 with the bottom level which is held in the bottom hold circuit 20 to amplify the error; numeral 24 denotes a servo amplifier for comparing the erase reference voltage outputted by the D/A converter 27 with a sample-hold level which is held in the sample-hold circuit 21 to amplify the error; numeral 25 denotes a servo amplifier for comparing the peak power reference voltage outputted by the D/A converter 28 with the peak hold level which is held in the peak hold circuit 22 to amplify the error; numerals 7,8 and 9 denote current sources for generating the currents corresponding to the outputs of the servo amplifiers 23,24 and 25, respectively; numeral 11 denotes a switch means for disconnecting the current source 8 with the semiconductor laser 10 in accordance with data EFM1; numeral 12 denotes a switch means for disconnecting the current source 9 with the semiconductor laser 10 in accordance with data EFM2.
Next, the operation will be described. A portion of the output light from the semiconductor laser 10 is received by the photodiode 1 and the generated photoelectric current is converted to a voltage in the monitor circuit 2.
At reproduction from the optical disk, the reproduction power reference voltage VR which is outputted by the D/A (Read/Bias) converter 26 serving as a reference voltage source and a voltage which is obtained by the bottom hold circuit 20 by sample-holding the output of the monitor circuit 2 are compared by the servo amplifier 23 and a current is passed through the semiconductor laser 10 by the current source 7 which is controlled by the comparison result of servo amplifier 23 so that a reproduction power PR corresponding to the reproduction power reference voltage VR is constantly outputted.
At recording into an optical disk, as shown in FIG. 2, the power of the semiconductor laser 10 is modulated into the three values of bias power PB, erase power PE, and peak power PP, thereby recording is performed into the optical disk. Then, a portion of the output light from the semiconductor laser 10 is received by the photodiode 1, and a signal corresponding to the optical output is outputted from the monitor circuit 2. The signal from the monitor circuit 2 is held by the bottom hold circuit 20, the sample-hold circuit 21, and the peak hold circuit 22 respectively, and the bottom level, the erase level and the peak level of the optical output are detected respectively. Initially, the bias power PB can be obtained by switching the output of the D/A (Read/Bias) converter 26 serving as a reference voltage source in FIG. 9 to switch over from the VR to the bias power reference voltage VB corresponding to the bias power PB. The bias power reference voltage VB and the voltage which is held in the bottom hold circuit 20 are compared by the servo amplifier 23, and a current is passed through the semiconductor laser 10 by the current source 7 which is controlled by the comparison result of servo amplifier 23 so that the bias power PB corresponding to the bias power reference voltage VB is constantly outputted.
Next, the erase power PE is obtained by comparing the erase power reference voltage VE outputted by the D/A(Erase) converter 27 serving as a reference voltage source and the output from the sample-hold circuit 21 by the servo amplifier 24 and by passing an erase power current through the semiconductor laser 10 with the erase power current superposed on the bias power current by the current source 8 which is controlled by the comparison result of servo amplifier 24.
Further, the peak power PP is obtained by comparing the peak power reference voltage VP outputted by the D/A(Peak) converter 28 serving as a reference voltage source and the output from the peak hold circuit 22 by the servo amplifier 25 and by passing a peak power current through the semiconductor laser 10 with the peak power current further superposed on the erase power current by the current source 9 which is controlled by the comparison result of servo amplifier 25.
Meanwhile, the erase power PE and the peak power PP are turned on and off by the switch means 11 and 12 which are switched by data EFM1 and EFM2, respectively, and therefore the power of the semiconductor laser is modulated between the bias power PB, the erase power PE and the peak power PP. As shown in FIG. 3, the interval at which the modulation is performed between the bias power PB and the peak power PP is the interval at which pits are formed on the track, and when the switch means 11 and 12 are in the state of on and off, respectively, the intervals at which the value of the erase power PE is maintained are the intervals where the space between pits are erased and spaces are formed. The three power values (the value of the bias power PB, the value of the erase power PE, and the value of the peak power PP) can obtain the desired power values by changing the respective reference voltages of D/A converters 26, 27 and 28 serving as the reference voltage sources.
The conventional semiconductor laser power control apparatus is constructed as above, and it can perform such a control that the powers of peak and bottom of the semiconductor laser should be predetermined by detecting the powers of peak and bottom of the semiconductor laser.
By the way, in a CD-R drive, a CD-RW drive or the like, the recording of data into an optical disk is performed at high speed by such as so-called double-speed recording which performs recording of data at an average rotation speed which amounts to N times (N is an integer of 2 or above) of the reproduction rotation speed of a music CD player as a reference, thereby, it is necessary to increase the modulation speed of the laser to a higher one, and for controlling the laser power at such high-speed modulation, the conventional construction requires to detect the bias power PB, the erase power PE, and the peak power PP, respectively, and therefore a monitor circuit, a bottom hold circuit, and a peak hold circuit which can perform high-speed responses are required, thereby resulting in an increase in costs.
That is, even when the laser is modulated at high speed and the high speed modulated light is incident on a monitor photodiode, if a photodiode and a monitor circuit having low response speeds are used, delays or unsharpening of signals would be generated therein and unsharpening of a monitor output signal would also occur, and therefore, as shown in FIG. 3, the optical output waveform cannot be correctly reflected on the monitor output and even if an output signal of the monitor circuit has become of high speed, as the signal becomes of higher speed, the detection efficiency of the bottom hold circuit and the peak hold circuit are lowered, thereby making it difficult that the peak output level and the bias output level should be detected correctly. In addition, in order to avoid these problems, it is required for a monitor circuit, a bottom hold circuit, and a peak hold circuit to have the capability of high-speed response, thereby resulting in an increase in costs.
The present invention is made to solve the above-mentioned problems and has for its object to provide a laser control apparatus which can perform a stable power control even at a high-speed modulation even though employing a monitor photodiode and a monitor circuit which operate at a relatively low speed.
According to Claim 1 of the present invention, there is provided a laser control apparatus which controls a power of a semiconductor laser in an optical recording/reproducing apparatus for performing recording/reproduction into/from an optical recording medium by a semiconductor laser, comprising: a reproduction power monitor means for monitoring an output of the semiconductor laser at reproduction just before recording; a bias power setting means for setting a bias power which is a minimum power outputted by the semiconductor laser at recording of pits into the optical recording medium, to a semiconductor laser driving means on the basis of a monitor value of the reproduction power monitor means; an erase power monitor means for monitoring an erase power which is a power outputted by the semiconductor laser at erasing between pits of the optical recording medium by sample-holding; an erase power setting means for setting the erase power to the semiconductor laser driving means on the basis of a monitor value of the erase power monitor means; and a peak power setting means for setting a peak power which is a maximum power outputted by the semiconductor laser at recording of pits into the optical disk to the semiconductor laser driving means, by operating a monitor value of the erase power monitor means.
According to Claim 1 of the present invention, the laser control apparatus is constructed as above, and therefore detects a power at reproduction just before recording and operates a bias power, and, as for an erase power, detects the power by a sample-hold and operates a peak power on the basis of the detected value of the erase power, and even if a low speed monitor photodiode and a low speed monitor circuit are employed, since the time when the erase power is being outputted is relatively long, the erase power can be correctly detected by the sample-hold and therefore the stable power control can be realized even at the high-speed modulation.
As described above, since the time when an erase power is being outputted is relatively long, the erase power can be detected correctly by a sample-hold, and by utilizing this, a laser control apparatus can realize the power control stably even at the high-speed modulation, even when a low speed monitor photodiode and a low speed monitor circuit are employed.
According to Claim 2 of the present invention, there is provided a laser control apparatus which controls a power of a semiconductor laser in an optical recording/reproducing apparatus for performing recording/reproduction into/from an optical disk by a semiconductor laser, comprising: a photodiode for detecting a light of the semiconductor laser; a current/voltage conversion means for converting a current of the photodiode to a voltage and outputting the voltage; a reference voltage source for deciding a reproduction power of the semiconductor laser; an error detection means for detecting an error between the voltage outputted by the current/voltage conversion means and the reference voltage; a current source for passing a current through the semiconductor laser; a reproduction power control system for connecting an output of the error detection means to the current source, and controlling the reproduction power of the semiconductor laser; a bias current setting means for deciding a bias current to be passed through the semiconductor laser; a switch means for selectively switching between an output of the error detection means and an output of the bias current setting means, and at the reproduction, connecting an output of the error detection means to the current source to form the reproduction power control system and, at the recording, connecting an output of the bias current setting means, instead of the output of the error detection means, to the current source; a sample-hold means for sample-holding the output voltage of the current/voltage conversion means at the recording; an erase current setting means for deciding an erase current to be passed through the semiconductor laser; a peak current setting means for deciding a peak current to be passed through the semiconductor laser; and an operation means for operating set values of the erase current setting means and the peak current setting means on the basis of an output value of the sample-hold means.
According to Claim 2 of the present invention, the laser control apparatus is constructed as above, and therefore controls a bias power with using an automatic power control (Automatic Power Control; hereinafter, referred to as APC) value at reproduction just before recording, and, as for an erase power, detects the power by the sample-hold and subjects the power to APC directly, and controls a peak power on the basis of the control value of the erase power, and, even when a low speed monitor photodiode and a low speed monitor circuit are employed, since the time when the erase power is being outputted is relatively long, the erase power can be correctly detected by the sample-hold, and therefore the power control can be realized stably even at the high-speed modulation.
As described above, a bias power is controlled by using an APC control value at the reproduction just before recording, an erase power is controlled by the power being detected by the sample-hold, and a peak power is controlled on the basis of the control value of the erase power, and thereby a laser control apparatus which can realize power control stably even at the high-speed modulation can be provided even when a low speed monitor photodiode and a low speed monitor circuit are employed.
According to Claim 3 of the present invention, there is provided a laser control apparatus which controls a power of a semiconductor laser in an optical recording/reproducing apparatus for performing recording/reproduction into/from an optical recording medium by a semiconductor laser, comprising: a semiconductor laser power monitor means for monitoring an output of the semiconductor laser; an output error detection means for detecting an error between an output power reference value which is to be outputted by the semiconductor laser at reproduction just before recording and an actual output power value at the reproduction, which value is detected by the semiconductor laser power monitor means; a semiconductor laser power control means for setting an output power target value to a semiconductor laser driving means on the basis of a detected result of the output error detection means; and an output power target value correction means for correcting the output power target value on the basis of a monitor value of an output of the semiconductor laser driving means after the output power target value is set.
According to Claim 3 of the present invention, the laser control apparatus is constructed as above. Thereby, it obtains an error between an actual output and an output reference value of a semiconductor laser when the state is changed from the reproduction state into the recording state, and sets, in accordance with the error, an output power target value to the semiconductor laser driving means, and monitors the output of the semiconductor laser driving means so as to correct the output power target value. Therefore, it is possible to set a bias power appropriately in accordance with a reproduction power as a reference.
As described above, the laser control apparatus which can appropriately set a bias power in accordance with a reproduction power as a reference can be obtained.
According to Claim 4 of the present invention, there is provided a laser control apparatus which controls a power of a semiconductor laser in an optical recording/reproducing apparatus for performing recording/reproduction into/from an optical disk by a semiconductor laser, comprising: a photodiode for detecting a light of the semiconductor laser; a current/voltage conversion circuit for converting a current of the photodiode to a voltage, and outputting the voltage; a reference voltage source for deciding a reproduction power of the semiconductor laser; an error amplifier for amplifying a difference between the voltage outputted by the current/voltage conversion circuit and the reference voltage; a current source for passing a current through the semiconductor laser; a reproduction power control system for connecting an output of the error amplifier to the current source, to control the reproduction power; a D/A conversion circuit for deciding a current to be passed through the semiconductor laser; a switch means for selectively switching between an output of the error amplifier and an output of the D/A conversion circuit, to make a control signal of the current source; and an A/D conversion circuit for selecting one of an output voltage of the error amplifier and an output voltage of the D/A conversion circuit, and subjecting the voltages to digital conversion, in which a digital value of the D/A conversion circuit is decided on the basis of a digital value of the A/D conversion circuit, and at the recording, the output of the error amplifier is switched over to the output of the D/A conversion circuit and the current of the current source is controlled.
According to Claim 4 of the present invention, the laser control apparatus comprises: a reproduction power APC system for controlling the reproduction power to make the power constant at the reproduction; an A/D converter for detecting a current control voltage at reproduction; a D/A converter for controlling a bias current at the recording; a switch circuit for switching the control to switch over from a reproduction power APC system to D/A converter at the recording; and an operation circuit for operating the D/A value on the basis of the A/D conversion value, and makes a bias current value controlling a bias power equal to a reproduction current value controlling a reproduction power and can set the bias power to be equal to the reproduction power.
As described above, a laser control apparatus which can make a bias current value controlling a bias power equal to a reproduction current value controlling a reproduction power by detecting a reproduction current value and a bias power current value, and can set the bias power to be equal to the reproduction power, can be obtained.
According to Claim 5 of the present invention, there is provided a laser control apparatus which controls a power of a semiconductor laser in an optical recording/reproducing apparatus for performing recording/reproduction into/from an optical disk by a semiconductor laser, comprising: a photodiode for detecting a light of the semiconductor laser; a current/voltage conversion circuit for converting a current of the photodiode to a voltage, and outputting the voltage; a reference voltage source for deciding a reproduction power of the semiconductor laser; an error amplifier for amplifying a difference between the output voltage of the current/voltage conversion circuit and the reference voltage; a current source for passing a current through the semiconductor laser; a D/A conversion circuit for deciding a current to be passed through the semiconductor laser; a switch means for selectively switching a control signal of the current source to switch between an output of the error amplifier and an output of the D/A conversion circuit; an A/D conversion circuit for subjecting an analog signal outputted from the current/voltage conversion circuit to digital conversion, and outputting the converted signal; and an operation circuit for, in a period during which recording is not performed, outputting a digital signal to the D/A conversion circuit, reading changes in the output signal of the A/D conversion circuit, obtaining a change amount in power in response to a change amount in the current of the semiconductor laser, and at the recording, outputting the digital signal value obtained above to the D/A conversion circuit.
According to Claim 5 of the present invention, the laser control apparatus comprises: a reproduction power APC system for controlling a reproduction power to make the power constant at the reproduction; an A/D converter for detecting a current control voltage at the reproduction; a D/A converter for controlling a bias current at the recording; a switch circuit for switching the control to switch over from the reproduction power APC system to the D/A converter at the recording; and an operation circuit for operating the D/A value on the basis of the A/D conversion value, and decides a bias current value to control a bias power with using a reproduction current value to control a reproduction power and can set the bias power freely.
As described above, a laser control apparatus which can obtain a bias power corresponding to a bias power current value previously, and can set the bias power freely, can be provided.
According to Claim 6 of the present invention, there is provided a laser control apparatus which controls a power of a semiconductor laser in an optical recording/reproducing apparatus for performing recording/reproduction into/from an optical disk by a semiconductor laser, comprising: a photodiode for detecting a light of the semiconductor laser; a current/voltage conversion circuit for converting a current of the photodiode into a voltage, and outputting the voltage; a reference voltage source for deciding a reproduction power of the semiconductor laser; an error amplifier for amplifying a difference between the output voltage of the current/voltage conversion circuit and the reference voltage; a current source for passing a current through the semiconductor laser; a reproduction power control system for connecting an output of the error amplifier to the current source, and controlling the reproduction power; a D/A conversion circuit for deciding a current to be passed through the semiconductor laser; a switch means for selectively switching between the output of the error amplifier and an output of the D/A conversion circuit, to make a control signal of the current source; an A/D conversion circuit for subjecting the output of the error amplifier to digital conversion; and an operation circuit for, in a period during which recording is not performed, outputting a digital signal to the D/A conversion circuit, reading changes in an output signal of the A/D conversion circuit, obtaining a change amount in power in respect to a change amount in the current of the semiconductor laser, and at the recording, outputting a digital signal value obtained in the period during which the recording is not performed, to the D/A conversion circuit.
According to Claim 6 of the present invention, the laser control apparatus takes a correction between an A/D converter detecting a current control voltage at the reproduction and a D/A converter controlling a bias current at the recording, and even when full scales are different or offsets are present between the A/D converter and the D/A converter, the bias power can be set highly precisely.
As described above, a laser control apparatus which, by taking a correction between an A/D converter detecting a current control voltage at the reproduction and a D/A converter controlling a bias current at the recording, can set a bias power highly precisely even when full scales are different or offset are present between the A/D converter and the D/A converter, can be provided.
According to claim 7 of the present invention, there is provided a laser control apparatus which controls a power of a semiconductor laser in an optical recording/reproducing apparatus for performing recording/reproduction into/from an optical recording medium by a semiconductor laser, comprising: a semiconductor laser power monitor means for monitoring an output of the semiconductor laser; an output error detection means for detecting an error between an output power reference value to be outputted by the semiconductor laser at reproduction just before recording and an actual output power value at the reproduction, which value is detected by the semiconductor laser power monitor means; a semiconductor laser power control means for setting an output power target value to a semiconductor laser driving means on the basis of the detected result of the output error detection means; a switch means for making a state between the semiconductor laser power monitor means and the output error detection means OFF at the recording, and making the state ON at the reproduction; and an output error setting means for setting the output of the output error detection means so as to be equal to the output power reference value at the recording.
According to Claim 7 of the present invention, the laser control apparatus is constructed as above. Thereby, it obtains an error between an actual output and an output reference value of the semiconductor laser when the state is changed from the reproduction state into the recording state, and, when an output power target value is set to the semiconductor laser driving means in accordance with the error, it sets the output error to be equal to the output power reference value without transmitting the monitor result of the semiconductor laser power monitor means to the output error detection means at the recording. Therefore, it is possible to avoid a transient response at switching from the recording state to the reproduction state.
As described above, a laser control apparatus which can avoid transient response when the state is switched from the recording state to the reproduction state, can be obtained.
According to Claim 8 of the present invention, there is provided a laser control apparatus which controls a power of a semiconductor laser in an optical recording/reproducing apparatus for performing recording/reproduction into/from an optical disk by a semiconductor laser, comprising: a photodiode for detecting a light of the semiconductor laser; a current/voltage conversion circuit for converting a current of the photodiode to a voltage, and outputting the voltage; a reference voltage source for deciding a reproduction power of the semiconductor laser; an error amplifier for amplifying a difference between the output voltage of the current/voltage conversion circuit and the reference voltage; a current source for passing a current through the semiconductor laser; a reproduction power control system for connecting an output of the error amplifier to the current source, and controlling the reproduction power; a D/A conversion circuit for deciding a current to be passed through the semiconductor laser; a switch means for selectively switching a control signal of the current source to switch between the output of the error amplifier and an output of the D/A conversion circuit; and a switch means for cutting off an input from the current/voltage conversion circuit into the error amplifier, in which at the recording, switching from the output of the error amplifier to the output of the D/A conversion circuit is performed to control the current of the current source, as well as the input from the current/voltage conversion circuit into the error amplifier is cut off, and at the reproduction, switching from the output of the D/A conversion circuit to the output of the error amplifier is performed to control the current of the current source, as well as the output of the current/voltage conversion circuit is connected to the input to the error amplifier, and the voltages of the reference voltage source, which decide the reproduction power, have different values at the recording and at the reproduction and, when switching from recording to reproduction is performed, the voltage of the reference voltage source is changed passing through at least one intermediate value.
According to Claim 8 of the present invention, a laser control apparatus which, being provided with a means for cutting off an input to a servo amplifier from a monitor circuit at the recording, and a means which can change a reference voltage of reproduction APC at switching from the recording state to the reproducing state, changes the reference voltage of the reproduction APC successively when the recording is switched to the reproducing, thereby to avoid the occurrence of an unusual output light according to transient response of the reproduction APC.
As described above, a laser control apparatus which, when the recording is switched to the reproducing, can change a reference voltage of reproduction APC successively, thereby to avoid the occurrence of an unusual output light according to transient response of the reproduction APC, can be provided. | {
"pile_set_name": "USPTO Backgrounds"
} |
It is known practice to dye keratin fibers, such as human hair, with dye compositions containing oxidation dye precursors, such as ortho- or para-phenylenediamines, ortho- or para-aminophenols, and heterocyclic compounds, which are generally referred to as oxidation bases. These oxidation bases, can be colorless or weakly colored compounds which, when combined with oxidizing products, may give rise to colored compounds by a process of oxidative condensation.
It is also known that the shades obtained with these oxidation bases may be varied by combining them with couplers or coloration modifiers, which may be chosen from aromatic meta-diaminobenzenes, meta-aminophenols, meta-diphenols and certain heterocyclic compounds such as indole compounds.
The variety of molecules that can be used as oxidation bases and couplers makes it possible to obtain a wide range of colors.
The “permanent” coloration obtained by means of these oxidation dyes should, moreover, satisfy a certain number of requirements. Thus, it should not have toxicological drawbacks, it should allow shades of the desired intensity to be obtained, and it should have good resistance to external agents such as light, bad weather, washing, permanent waving, perspiration and rubbing.
The dyes may also allow white hairs to be covered and, lastly, they may be as unselective as possible, that is to say that they may allow the smallest possible differences in coloration to be produced over the entire length of the same keratin fiber, which is generally differently sensitized (e.g., damaged) between its end and its root. | {
"pile_set_name": "USPTO Backgrounds"
} |
International Standard ISO-FIX has been established, specifying the method for fixing the child seat to the vehicle seat. Japanese Patent Application Laid-Open No. 2010-155516 (Patent Literature 1) discloses background art of the vehicle seat configured to store ISO-FIX compatible anchor capable of fixing the ISO-FIX type child seat. The vehicle seat disclosed in Patent Literature 1 has been made to accomplish the task of improving the child seat mountability without deteriorating seating feel when the child seat is demounted. The vehicle seat has an anchor member to be engaged with a fixture of the child seat, which is disposed at the back side of the seat main body constituted by the pad material and the skin material for covering the outer side of the pad material, a through path extending from the front surface to the anchor member, and the slit formed in the skin material at the front surface side of an insertion opening of the through path. The above-described vehicle seat includes an extension member provided for the slit, extending to the region outside the insertion opening. | {
"pile_set_name": "USPTO Backgrounds"
} |
1. Technical Field
The present invention relates to an image data producing apparatus and an image forming apparatus for producing image data from data described in the page description language (PDL).
2. Related Art
As for the image forming apparatus, various prior arts have been proposed to execute the process at a high speed in forming a raster image (data) from the data described in the page description language. | {
"pile_set_name": "USPTO Backgrounds"
} |
According to recent publications the morphine metabolite Morphine-6-xcex2-D-glucuronide (M6G) [6] is a more effective and longer lasting analgesic drug than Morphine [5] with fewer side effects1 and, therefore, there is much interest in using M6G, rather than Morphine, as a pain killing drug.2
The traditional approach to glycosylation of 4,5-Epoxymorphinan-6-ols explores Bromoglucuronides as glycoside donor and the Koenings-Knorr procedure for the activation of Bromoglucuronides (Berrang, B., et al., Synthesis, 1997, p. 1165 and references cited therein).
Another approach (Scheinmann, F. et. al., U.S. Pat. No. 5,621,087, see claim 1, 2, 5 and 6, abstract, examples, column 4, line 25-line 45) explores the use of Lewis acids (of the type BF3 and TMSOTf) rather than heavy metals based Lewis acids (March, J., xe2x80x9cAdvanced Organic Chemistryxe2x80x9d, 4-th edition, A Whiley-Interscience publicaiton, pp. 260-3) for the activation of Bromoglucuronides.
Unfortunately, we did not succeed to obtain 4,5-Epoxymorphinan-6-oxyglucuronide from Bromoglucuronides using activators proposed in U.S. Pat. No. 5,621,087 and did not find such examples in the literature.
Unexpectedly we found that the O-glycosylation of 4,5-Epoxymorphinan-6-ols with Bromoglucuronides was accelerated by Zinc containing compounds to give 4,5-Epoxymorphinan-6-oxyglucuronides of formula [1] with high yield.
wherein:
position 7 and 8 can be olefin as shown or dihydro adduct;
R1 are alkyl, haloalkyl, arylmethyl, acyl, alkoxycarbonyl, aralkoxycarbonyl, haloalkoxycarbonyl, vinyloxycarbonyl or allyloxycarbonyl,
R2 is alkyl, haloalkyl or aralkyl;
R3 is alkyl, arylmethyl, allyl, cyclopropylmethyl, cyclobutylmethyl, acyl, alkoxycarbonyl, aralkoxycarbonyl, haloalkoxycarbonyl, vinyloxycarbonyl, allyloxycarbonyl or hydrogen;
R4 is alkyl, haloalkyl, arylmethyl, 2-(4-morpholinyl)ethyl, acyl, alkoxycarbonyl, aralkoxycarbonyl, haloalkoxycarbonyl, vinyloxycarbonyl or allyloxycarbonyl.
We also found that the xcex1 and xcex2 anomeric selectivity of the conjugation product can be controlled by using different O-protecting groups in aglycon and in Bromoglucuronide as well as by varying the ratio between 4,5-Epoxymorphinan-6-ols and Zinc containing compounds.
It is important to note that only the xcex2-anomer of 4,5-Epoxymorphinan-6-oxyglucuronides was obtained according to Koenings-Knorr procedure and U.S. Pat. No. 5,621,087 procedure (but with other than a Bromoglucuronide glycoside donor).
All of the previously disclosed methods have serious drawbacks for producing material to be used as a pharmaceutical drug. A desirable goal, met by the present invention, has been to devise a synthetic procedure without using commercially inaccessible and expensive reagents, and which cleanly produces the desired 4,5-Epoxymorphinan-6-oxyglucuronides, avoiding tedious and expensive purification steps.
The present invention provides a commercially acceptable process for conjugation of 4,5-Epoxymorphinan-6-ols of formula [3] with Bromoglucuronides of formula [2] in the presence of Zinc containing compounds under conditions capable of forming 4,5-Epoxymorphinan-6-oxyglucuronides [1].
wherein
position 7 and 8 can be olefin as shown or dihydro adduct;
R1, R2, R3, and R4, are as defined above.
This novel approach was used for the preparation of the known analgesic agent Morphine-6-xcex2-glucuronide [4] and of its xcex1-anomer.
Other features and advantages will be apparent from the specification and claims.
The present invention is related to a novel process for conjugation of 4,5-Epoxymorphinan-6-ols with Bromoglucuronides.
Particularly, the present invention relates to the use of Zinc containing compounds for the activation of Bromoglucuronides in the O-glycosylation reaction of 4,5-Epoxymorphinan-6-ols.
This novel approach has the following advantages:
Zinc containing compounds as activating reagents of Bromoglucuronides are inexpensive and commercially available.
Use of different O-protecting, groups in the aglycon and in the Bromoglucuronide as well as different ratio of 4,5-Epoxymorphinan-6-ols and Zinc containing compounds enable to obtain high anomeric selectivity and produce at will with a high degree of preference either the xcex1 or the xcex2 anomer.
Although any 4,5-Epoxymorphinan-6-ols are suitable for this O-glycosylation, preferably, compounds of formula [3] are used
wherein
position 7 and 8 can be olefin as shown or dihydro adduct;
R3 and R4 are as previously defined.
More preferably, said 4,5-Epoxymorphinan-6-ols are selected from 3-O-Acylmorphine, 3-O-Acylnormorphine, 3-O-Acylnalbuphine, 3-O-Acylnalorphine, 3-O-Acyldihydromorphine, 3-O-Benzylmorphine, 3-O-Benzyldihydromorphine, N,O3-Dibenzylnormorphine, Codeine, Ethylmorphine, Dihydrocodeine, Pholcodine, 3-O-Alkoxycarbonylmorphine, 3-O-Benzyloxycarbonylmorphine, N,O3-Bis(benzyloxycarbonyl)normorphine.
Although any Bromoglucuronide may be used, it is preferred that compounds of formula [2] are used.
wherein
R1 and R2 are as previously defined.
More preferably the Bromoglucuronides of the present invention are selected from the compounds of formula [2a].
wherein
R are acyl, alkoxycarbonyl, aralkoxycarbonyl, haloalkoxycarbonyl, vinyloxycarbonyl, allyloxycarbonyl;
R2 is as previously defined.
Most preferably Bromoglucuronides of formula [2b] are used.
wherein
R are as previously defined.
Although any Zinc containing compound suitable as activating reagents for this O-glycosylation can be used, preferably, Zinc Bromide is used.
It is preferred that about 0.01 equivalents to about 4 equivalents and especially preferred that about 0.5 equivalents to about 2 equivalents of Zinc containing compound is used.
Preferably about 1 equivalent to about 2 equivalents of the Bromoglucuronide [2] is used. It is specially preferred that about 1 equivalent to about 1.5 equivalents of Bromoglucuronide [2] is used. The said 4,5-Epoxymorphinan-6-ol [3] may be used as an individual compound or alternatively as corresponding salts thereof or complexes. Especially preferred is the use of said Zinc containing salt or complexes of [3] without using additional Zinc containing compounds as promoter for said coupling. It is preferred that the said complexes may be prepared in situ.
It may be also preferred to conduct the said Zinc activated O-glycosylation in the presence of additives to buffer or to promote the said Zinc containing compounds. The above additives may be selected from molecular sieves, tertiary amines, tetraalkylureas, organic and inorganic acids and salts.
Any reaction-inert solvent may be used. As used above and elsewhere herein, the expression xe2x80x9creaction-inert solventxe2x80x9d refers to a solvent which does not react or decompose with starting materials, reagents, intermediates or products in a manner which adversely affects the yield of the desired product. In general, the solvent can comprise a single entity, or contain multiple components. Preferably the sovent is a non-protic reaction inert solvent and it is especially preferred that the solvent is Dichloromethane because of the exellent stereoselectivity it provides. Another solvent may be Chloroform or Dichloroethane.
Any environment or conditions (e.g. temperature, time, solvent) suitable for (i.e., capable of) forming the desired 4,5-Epoxymorphinane-6-oxyglucuronides may be used. However, it is preferred that the reaction occurs at a temperature of about xe2x88x9220xc2x0 C. to about 100xc2x0 C. and preferably from about 40xc2x0 C. to 65xc2x0 C. Below about xe2x88x9220xc2x0 C. the reaction can be slow and above about 100xc2x0 C. undesired side reactions (e.g. anomerisation) can occur. This reaction is conveniently carried out at about 0.5 to about 3 atmospheres, however, the high pressures are espesially preferred for the said coupling.
The present invention could be used as a general method to produce a large number of new compounds. As a result of the said coupling also the salts and complexes of 4,5-epoxymorphinan-6-oxyglucuronides [1] could be obtained in a convenient way.
This invention makes a significant advance in the field of 4,5-Epoxymorphinan-6-oxyglucosides by providing efficient methods of preparing both anomers of 4,5-Epoxymorphinan-6-oxyglucuronides. The deprotected end products are useful as analgesic agents.
It should be understood that the invention is not limited to the particular embodiments shown and described herein, but that various changes and modifications may be made without departing from the spirit and scope of this novel concept as defined by the following claims. | {
"pile_set_name": "USPTO Backgrounds"
} |
Coal, formed from decomposed and compressed vegetable matter, is typically found in substantially horizontal seams extending between sedimentary rock strata such as limestone, sandstone or shale. Surface and underground mining are the primary techniques used to recover this coal.
Surface or strip mining involves the removal of material, known as overburden, overlying a coal seam so as to expose the coal for recovery. In recent years, surface mining has gained prominence over underground mining in the United States. This is due to many factors including:
(a) the increased material moving capacity of surface or strip mining equipment; PA1 (b) lower costs for surface mining than underground mining; PA1 (c) the better safety record of surface mining versus underground mining; PA1 (d) the higher coal recovery percentage for surface mining versus underground mining; and PA1 (e) the fact that geological factors favor extraction of many coal reserves by surface mining.
Surface mining does, however, have its limitations despite the advantages cited above. The primary limiting factor relates to the depth of the overburden. Once the coal seam reaches a certain depth below the surface, the amount of overburden that must be removed to reach the coal simply makes strip mining economically unfeasible.
When this occurs, large quantities of coal may still remain in the ground. Other mining methods must, however, be utilized if economic recovery of this coal is to be achieved. Underground mining application in such an instance is, typically, very limited. This may be due to a number of factors including the existence of poor roof support conditions, the thinness of the seam and/or the presence of insufficient quantities of coal to warrant the large capital investments characteristic of underground operations.
Due to these considerations, auger mining is often used to recover coal following a strip mining operation where the overburden becomes too costly to remove. A large auger is used to bore into the face of the seam and recover the coal from beneath the overburden. Advantageously, auger mining is very efficient providing more tons per man per day than any other form of mining. Auger mining may also be initiated quickly and requires a relatively low capital expenditure when compared to surface and underground mining. Auger mining has also been found to date to be the best method to use in relatively thin seams. Further, auger mining is safer than both surface and underground mining. Thus, auger mining may be used to effectively supplement a strip mining operation and recover small coal deposits that would otherwise be left behind.
Auger mining is, however, also not without its disadvantages. Auger mining provides a relatively low total coal recovery. Coal recovery for the resource area being augured is usually less than about 35%. Some of the lost recovery is due to the pillars of coal that are left standing to support the overburden between adjacent auger holes. The majority of the recovery shortfall, however, is due to the limited penetration depths achievable with auger mining equipment.
More particularly, as penetration depths increase, a greater number of auger flights are required to convey the coal from the cutting head to the seam face for recovery. Each flight adds to the frictional resistance to the turning of the auger through contact with the walls of the bore hole. Additionally, the longer the string of auger flights, the greater the weight of coal being moved by the flights at any one time. As a result, it should be appreciated that auger power requirements increase rapidly with the depth of auger penetration.
Due to the above considerations, holes drilled by conventional auguring equipment are usually only of a depth of 150' with 200' being rarely attainable. Of course, any increase in this figure is desirable as it would greatly improve the coal recovery rate from a resource area. | {
"pile_set_name": "USPTO Backgrounds"
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Apparatus for the separation of air gases is generally supplied with air from at least one isothermal compressor provided with interstage refrigeration, in which the air is cooled by heat exchange with the refrigeration air.
The air leaving the compressor is itself cooled in a final cooler or in an air/water tower, generally associated with a water/nitrogen tower and/or a refrigeration group. This system, generally called "precooling", permits obtaining air at a relatively low temperature (about 15.degree. C.) before directing it toward a dryer, thereby limiting the load on this latter, the quantity of water contained in the air increasing exponentially with temperature. Such systems are described in "Current Alternatives by the Use of CFCs in Air Separation and Liquefaction Processes" by Walter F. Castle, Kryogenika 1996.
It is known to use the heat of the refrigerant of the compressor to reheat the regeneration gas, from JP 62-335691, JP 196772/94, and FR-2 686 405 and JP 7-144114.
However, the compressors used are isothermal compressors.
It is an object of the present invention to decrease the cost of an air separation unit. | {
"pile_set_name": "USPTO Backgrounds"
} |
1. Field of the Invention
This invention relates to a communication system having one or more terminal devices which process content information according to service details, a management device which manages information with regard to service provided by the terminal device, and an information storage device which retains content information. This invention further relates to an information storage device, management device, and terminal device constituting the system.
Priority is claimed on Japanese Patent Application No. 2008-138142, filed May 27, 2008, the content of which is incorporated herein by reference.
2. Description of the Related Art
Communication systems which transmit image data to external equipments (image reception devices, printing devices, and similar) on a network from an image capture device are known. Patent Reference 1 describes a method in such a communication system. In order to monitor the state of external equipment, in which output mode information of a printing device is acquired and managed, an output mode settings screen program which can be displayed on various terminals is generated, and the output mode settings screen program is transmitted to various terminals. Patent Reference 1: Japanese Unexamined Patent Application, First Publication No. 2003-330656 | {
"pile_set_name": "USPTO Backgrounds"
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The present invention relates to optical filters, and more particularly, to tunable Fabry-Perot optical resonators, and filters and lasers constructed therefrom.
Tunable optical resonators are utilized in optical communication systems and in the construction of lasers. Optical filters and lasers based on Fabry-Perot resonators can be constructed using microelectromechanical (MEM) machining techniques, and hence, in principle, can provide an economically attractive tunable filter or tunable laser. In such devices, a Fabry-Perot resonator cavity is formed between two mirrors. One of these mirrors is flat and located on a semiconductor substrate. The other mirror may be curved and is suspended on a number of micro-mechanical cantilevers. Application of a tuning voltage between the cantilevers and the substrate causes the suspended mirror to move towards the fixed mirror on the substrate, thereby reducing the spacing between the two mirrors of the Fabry-Perot resonator. Since the filter""s bandpass frequency is determined by the mirror spacing, a reduction in spacing between the two mirrors causes the resonant optical frequency of the cavity to increase. The shift in the resonant frequency enables the device to be used directly as a tunable bandpass filter. If an optically-pumped or electrically-pumped optical gain medium (active region) is placed in the cavity, the device becomes a tunable laser, with the lasing wavelength controlled by the resonant frequency of the Fabry-Perot cavity.
In many prior art MEM Fabry-Perot resonators the tuning voltage needed to provide a specific resonance frequency depends on the power in the light that is resonating within the cavity. This power dependent tuning makes the use of such resonators difficult in applications in which the power level in the resonator changes with time.
Broadly, it is the object of the present invention to provide an improved MEM Fabry-Perot resonator.
It is a further object of the present invention to provide a MEM Fabry-Perot resonator having a tuning voltage that is independent of the optical power level in the resonator.
These and other objects of the present invention will become apparent to those skilled in the art from the following detailed description of the invention and the accompanying drawings.
The present invention is a tunable optical resonator constructed from a fixed mirror and a moveable mirror. The fixed mirror is attached to a substrate having a first electrically conducting surface. A support member having the moveable mirror supported thereon and a second electrically conducting surface is suspended above the substrate such that the moveable mirror is separated from the fixed mirror. A light output port transmits a light signal of a wavelength determined by the distance between the fixed and moveable mirrors. An optical circuit measures the power level of the light signal and generates an electrical signal that depends on the measured power level. A frequency adjustment circuit, responsive to the electrical signal and a tuning voltage, applies an electrical potential between the first and second electrically conducting surfaces. The electrical potential causes the distance to remain at a value determined by the tuning voltage independent of the power level for power levels less than a predetermined power level. The resonator can be used to construct a laser by incorporating an active layer for amplifying light trapped in the cavity. The resonator can also be used as a tunable optical filter by including an input port for receiving a light signal that is to be filtered. In one embodiment of the invention, a feedback circuit consisting of an optical coupler, photodiode, amplifier, and signal adder is used to generate the potential between the first and second electrically conducting surfaces. | {
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Waterbeds have been in widespread use for many years and consist generally of a flexible, hollow plastic shell and a supporting frame. Waterbeds support the weight of a human body at all points and were first developed for medical use, although they have now gained common acceptance for residential use.
Much development in the use, care, and added accessories for waterbeds has taken place. A fundamental and long-standing problem in the sale and ownership of a waterbed has been in draining the water from the mattress. A number of new inventions have been patented concerning the draining of waterbeds, but these innovations have involved syphon or Venturi type pumps. Examples of such waterbed pumps are found in the U.S. Pat. Nos. of Mollura (3,797,538); Houk (4,332,044) and Callaway (4,399,576). Each of these inventions advanced the art of draining waterbeds, but each failed to provide for any type of electrically assisted pumping.
Heretofore, the normal draining operation of a waterbed could take anywhere from 2 to 6 hours by use of the syphon method. The more efficient pumps require two long hoses to stretch between the waterbed drain-filler neck and a suitable sink, bathtub, or outside drain and uses a large amount of tap water to facilitate the syphoning process. Because a syphon pump requires the drawing of a partial vacuum, the hoses used in these procedures also had to be rigid.
The new innovation presented here includes an electrically enhanced pump. Because of the nature of an electric pump, moreover, a base or boot has been adapted to keep the electric pump in an upright position on the waterbed as the waterbed deflates from the removal of water therefrom.
Although large sized electric bilge pumps have been borrowed from the boat field, these larger pumps are not commercially practical for the average consumer. What was needed heretofore was a light weight yet highly efficient and economical electric waterbed pump. To enable the commercialization of such a pump especially adapted to the waterbed industry, certain modification of existing pump and pumping art are presented herein.
A primary purpose of this invention is to provide a lightweight, highly efficient and economical pump particularly adapted for use on waterbeds.
Another purpose is to provide a commercially feasible pump for a waterbed capable of draining a waterbed in a short period of time, usually under two hours, using electromotive force.
A still further object of the invention is to provide a base or boot for the lightweight waterbed pump that enables said pump to remain in an upright position as the waterbed draws.
Further objects of this invention will become obvious upon reviewing the specification herewith. | {
"pile_set_name": "USPTO Backgrounds"
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1. Field of the Invention
This invention relates to surgical instruments and more particularly to an improved electrosurgical knife.
2. Prior Art
Electrosurgery is a well-known technique in which a high-frequency electrical current is conducted through a surgical instrument into the tissue of a patient to effect electrocoagulation and/or electrocauterization. In electrosurgery, the surgical instrument and the patient are both connected to a source of high-frequency current, and the instrument is provided with a metallic device such as a blade, that functions as an electrode for conducting the high-frequency current to the tissue of the patient. As the surgeon brings the electrode in contact with the tissue, the current passes through the patient to a second electrode connected elsewhere to the body of the patient to complete the current path back to the source of high-frequency current. Because the point of contact between the instrument electrode and the patient is comparatively small, the relative current density and electrical resistance are comparatively high, resulting in electrocoagulation and/or electrocauterization at the point of contact.
One of the advantages of electrosurgery is that it allows the surgeon to perform very exact surgery by touching the electrode blade to the precise area to be treated. A disadvantage of this type of surgery, however, is that the flow of current through the tissue often generates smoke in the vicinity of the electrode. Except in well ventilated areas, the smoke tends to block the view of the surgeon. A more serious concern is that the smoke may be contaminated with viruses from the patient which may be transmitted to anyone who inadvertently inhales the smoke. To protect the medical staff from exposure to the virus of deadly or crippling diseases, it is important to aspirate the smoke from the immediate surgical area before it dissipates into the air breathed by the attendants. To solve this problem, it is sometimes necessary to have a separate attendant hold an aspiration tube adjacent the electrode while the surgeon is performing the operation. The disadvantages of such an arrangement are obvious. The electrosurgical technique may be used for sealing off blood vessels and hence, the surgeon may be required to operate in an area where blood tends to accumulate and particulates may be collected. Accordingly, it is desirable to have a means for removing accumulated blood and particulates as well as smoke from the surgical area. In an analogous fashion, some surgical procedures may require an additional source of light so that the surgeon may be able to adequately view the area to be treated, while in other situations no such additional light is required.
Examples of patents disclosing prior art electrosurgical instruments are as follows:
U.S. Pat. No. 3,828,780 to C. F. Morrison, Jr. (dated Aug. 13, 1974) describes a combined electrosurgical and suction instrument. The instrument consists essentially of an elongated body having a hollow metal tube with a distal end functioning as the electrode and having a proximal end connected to an electrical wire in the housing. Suction is applied to the proximal end of the hollow metal tube so as to remove fluids through the tube electrode.
U.S. Pat. No. 3,825,004 to J. G. Durden III (dated Jul. 23, 1974) discloses a disposable electrosurgical cautery having a handle constructed of upper and lower halves forming a cavity for accommodating a hollow metal tube. The distal end of the tube is used as the electrode and the proximal end is connected to an electrical wire and a vacuum hose to withdraw fluids through the tube electrode.
U.S. Pat. No. 3,906,955 to R. R. Roberts (dated Sep. 23, 1975) discloses an electrosurgical tool having a housing with an electrode disposed at the distal end of the housing and connected to electrical wiring within the housing. A separate vacuum tube contained within the housing and extending beyond the distal end of the housing is disposed adjacent the electrode to withdraw fluid from the cutting area. The housing is provided with a manually-operable slide which is rigidly attached to the vacuum tube internal to the housing and which may be used to position the distal end of the vacuum tube within the range of travel of the manually-operable slide.
U.S. Pat. No. 3,974,833 to J. G. Durden III (dated Aug. 17, 1976) discloses a surgical knife with a combination cutting electrode and vacuum tube such as that disclosed in U.S. Pat. No. 3,825,004 referenced above, and is further provided with an aperture in the knife handle communicating with an opening in the vacuum tube. By selectively covering the aperture in the handle with a finger, the surgeon controls the amount of suction applied to the surgically treated area.
U.S. Pat. No. 4,562,838 to W. S. Walker (dated Jan. 7, 1986) discloses an electrosurgical knife having a generally cylindrical housing and an electrode extending from a central opening in the housing at the distal end thereof. The housing is provided with a number of ducts at the distal end thereof in communication with a cavity internal to the housing. A hose, which may be either connected to a sterile air-pressure source or a vacuum source, is connected to the fluid cavity within the housing and may be used to aspirate smoke or to distribute an airflow in the area of the surgical blade. The housing is further provided with a mounting channel along its upper edge for slidably receiving a light-transmitting cable of a fiber-optic system to illuminate the region around the cutting blade.
Disadvantages of these and other prior art devices are that the electrosurgical knives have become relatively bulky and complex structures which are not inexpensive to manufacture. The prior art devices are often difficult to hold and lack the flexibility that is desired by many surgeons. Surgeons in a number of hospitals use the less expensive standard electrosurgical knives which do not have the aspirating capability or a separate light source to perform operations in well-ventilated and well-lighted areas, and use the more expensive, specialized knives only when required. This means that the hospitals must have multiple inventories. It is therefore desirable to provide a surgical knife which is inexpensive and optionally provides the capabilities of the more specialized knives.
A particular disadvantage of prior art electrosurgical knives is the inability to withdraw smoke and other fluid and particulates from the immediate vicinity of the electrode when electrodes of different types and lengths are used. The distance of the electrode from the knife handle may vary greatly, e.g., from approximately 1 inch to over 12 inches. The shape of the electrodes may be that of a tube, a flat blade, a loop, a needle, or other configurations. Prior art devices do not provide an electrosurgical knife which is readily adaptable to provide aspiration at the surgical contact area for the various electrodes used in electrosurgery. | {
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1. Field of the Invention
The invention relates to a semiconductor package, and more particularly, to a multi-chip semiconductor package.
2. Description of the Related Art
As electronic products are getting smaller and lighter, the packages for protecting and interconnecting IC chips also have the same trend.
With ever-increasing demands for miniaturization and higher operating speeds, multi-chip packages have become an attractive approach in a variety of electronic device. Multi-chip packages, which contain two or more chips in a single package, can help minimize the limitation in system operation speed. In addition, multi-chip packages are capable of decreasing the interconnection length between IC chips thereby reducing signal delays and access times.
Referring to FIG. 1, a conventional stacked chip package 10 includes a substrate 11 with a chip 12 disposed thereon. The chip 12 is electrically connected to the substrate 11 by a plurality of bumps 14. A chip 13 is stacked on the chip 12 and electrically connected to the chip 12 by a plurality of bumps 15. A sealant 16 is disposed on the substrate 11 and used to encapsulate the chips 12, 13 to protect these chips from damage.
However, the package 10 uses a substrate, not a leadframe to carry chips. Moreover, it is not feasible to stack another package on the package 10.
Referring to FIG. 2, U.S. Pat. No. 6,977,431 discloses a stackable semiconductor package 200. The package 200 includes a metal die pad 110, a plurality of metal leads 115, each of which includes an inner lead portion 120 embedded in a plastic sealant 170 and an outer lead portion 130 that is fully disposed outside of the sealant 170. The die pad 110 includes an approximately planar first surface 111 and an approximately planar second surface 112 that is opposed to the first surface 111. A chip 140 is positioned in the sealant 170 and mounted to the second surface 112 of the die pad 110. A plurality of conductive wires 160 electrically connects the chip 140 to the inner lead portions 120. The first surface 111 of the die pad 110 is fully exposed out of the first surface 171 of the sealant 170.
Referring to FIG. 3, the above-mentioned U.S. patent also discloses that another semiconductor package 300 is capable of being stacked on the first surface 171 of the sealant 170 of the package 200. The package 300 includes a die pad 210 with a chip 230 disposed on the upper surface thereof. A plurality of conductive wires 250 is used to electrically connect the chip 230 to the leads 220 surrounding die pad 210. The chip 230, upper surface of the die pad 210 and upper surfaces of the leads 220 are covered by a sealant 260. The lower surface of the die pad 210 and lower surfaces of the leads 220 are exposed out of the sealant 260. A conductive layer 270 made of such as metal solder or conductive epoxy-based material is disposed between the packages 200 and 300 so as to electrically connect the lower surface of the die pad 210 to the first surface 111 of the die pad 110 and to electrically connect the leads 220 to the inner lead portions 120 of the leads 115.
Although the assembly of the package 200 and package 300 contains two chips 140 and 230, the assembly uses two die pads 110, 210 to respectively carry the chips 140 and 230. This will cause an increase in material cost.
Accordingly, there exists a need to provide a multi-chip package to solve the above-mentioned problems. | {
"pile_set_name": "USPTO Backgrounds"
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1. Field of the Invention
The present invention relates to polyimide-based polymers containing dianhydride moieties having a particular structure in the repeating units thereof, and/or copolymers of the polyimide-based polymers. The present invention also relates to a positive type photoresist composition comprising at least one of the polyimide-based polymers and/or copolymers thereof as a binder resin to achieve high resolution, high sensitivity, excellent film characteristics and improved physical properties.
2. Description of the Related Art
With the recent trend toward higher integration, higher density, higher reliability and higher speed of electronic devices in the field of semiconductors and semiconductor devices, particularly, liquid crystal display devices, considerable research efforts have been made to utilize the inherent advantages of organic materials that are easy to process and purify. However, organic polymers for use in the field of semiconductors and semiconductor devices should be thermally stable even at temperatures as high as 200° C. in the device fabrication processes.
Polyimide compounds have good thermal stability and excellent mechanical, electrical and chemical properties. These advantages have extended the application of photoresists and photosensitive insulating films including polyimide compounds to the field of semiconductors and displays. Under these circumstances, there is a need for polyimide-based polymer compounds that do not undergo film reduction and swelling in the formation of fine patterns, which have previously not been required in conventional polyimide photoresists.
A polyimide polymer is typically prepared by two-step polycondensation of a diamine and a dianhydride in a polar organic solvent, such as N-methyl-2-pyrrolidone (NMP), dimethylacetamide (DMAc) or dimethylformamide (DMF) to obtain a polyimide precursor solution, coating the polyimide precursor solution on a silicon wafer or glass, and curing the coating by baking. Commercially available polyimide products for electronic materials are supplied in the form of polyimide precursor solutions or polyimide films. Polyimide precursor solutions are main forms of polyimide products supplied in the field of semiconductor devices.
Polyimide resins are applied to the production of buffer coating films of semiconductor devices. In a large-scale integrated (LSI) circuit, volume shrinkage of a resin after packaging and thermal stress arising from the difference in the coefficient of thermal expansion between a chip and the resin induce cracks in a passivation film of the chip and damage to metal interconnections. In an effort to solve such problems, a buffer layer composed of a polyimide is formed between the chip and the packaging material. The buffer layer should be as thick as 10 μm to perform its role. The thicker the buffer layer, the better the buffering effect, leading to an improvement in the yield of semiconductor products.
A polyimide layer requires the formation of fine patterns, such as electrode interconnections and wire bonding pads. Via holes are formed in the polyimide layer by coating a photoresist on a conventional non-photosensitive polyimide film, followed by etching. In recent years, many attempts have been made to apply photosensitive polyimides to the formation of via holes. The use of a conventional non-photosensitive polyimide requires etching for processing holes through a photoresist to bond wires and connect metal interconnections, whereas the use of a photosensitive polyimide can eliminate the need for lithography using a photoresist. In the latter case, the buffer coating process is shortened by about 50%, resulting in productivity improvement and cost reduction. The final step of the semiconductor device fabrication process is also shortened, greatly contributing to an improvement in production yield.
Research is being actively undertaken on positive type photosensitive polyimides rather than on negative type photosensitive polyimides for the following reasons.
The first reason is that a positive type photosensitive polyimide has a higher resolution than a negative type photosensitive polyimide. The second reason is that a positive type photosensitive polyimide is exposed in a relatively small area, compared to a negative type photosensitive polyimide, indicating low possibility of defects. The third reason is that the use of a negative type photosensitive polyimide causes problems in terms of production cost and environmental pollution (e.g., waste water treatment) because it requires an organic solvent such as N-methyl-2-pyrrolidone (NMP) or dimethylacetamide (DMAc) as a developer, while the use of a positive type photosensitive polyimide is economically advantageous and environmentally friendly because it requires an alkaline aqueous solution as a developer.
Many methods have been developed to impart polyimide resins with photosensitivity, for example, by chemically bonding cross-linkable functional groups to the polyimide precursors or mixing cross-linkable monomers with the polyimide precursors, in order to use the polyimide resins for the preparation of photoresist compositions.
As another example, a quinonediazide compound is added to a polyamic acid, a polyamic ester having acid functional groups in the side chains thereof or a polyimide having acid functional groups in the side chains thereof. However, high solubility of the polyamic acid in an alkaline developer causes the problem of film reduction upon development, which requires the addition of an amine, etc. Further, the polyimide or the polyamic ester has high resolution, but the acid functional groups remain even after curing, causing the problems of high water absorption or poor alkali resistance of the cured film.
Thus, there is an urgent need in the art to develop high-resolution polyimide compounds that do not suffer from film reduction or swelling during fine pattern formation while possessing appropriate solubility in alkaline developers. | {
"pile_set_name": "USPTO Backgrounds"
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1. Field of the Invention
The present invention relates generally to optics and, more specifically, the present invention relates to modulating optical beams.
2. Background Information
The need for fast and efficient optical-based technologies is increasing as Internet data traffic growth rate is overtaking voice traffic pushing the need for optical communications. Transmission of multiple optical channels over the same fiber in the dense wavelength-division multiplexing (DWDM) systems and Gigabit (GB) Ethernet systems provide a simple way to use the unprecedented capacity (signal bandwidth) offered by fiber optics. Commonly used optical components in the system include wavelength division multiplexed (WDM) transmitters and receivers, optical filter such as diffraction gratings, thin-film filters, fiber Bragg gratings, arrayed-waveguide gratings, optical add/drop multiplexers, lasers and optical switches. Optical switches may be used to modulate optical beams. Two commonly found types of optical switches are mechanical switching devices and electro-optic switching devices.
Mechanical switching devices generally involve physical components that are placed in the optical paths between optical fibers. These components are moved to cause switching action. Micro-electronic mechanical systems (MEMS) have recently been used for miniature mechanical switches. MEMS are popular because they are silicon based and are processed using somewhat conventional silicon processing technologies. However, since MEMS technology generally relies upon the actual mechanical movement of physical parts or components, MEMS are generally limited to slower speed optical applications, such as for example applications having response times on the order of milliseconds.
In electro-optic switching devices, voltages are applied to selected parts of a device to create electric fields within the device. The electric fields change the optical properties of selected materials within the device and the electro-optic effect results in switching action. Electro-optic devices typically utilize electro-optical materials that combine optical transparency with voltage-variable optical behavior. One typical type of single crystal electro-optical material used in electro-optic switching devices is lithium niobate (LiNbO3).
Lithium niobate is a transparent material from ultraviolet to mid-infrared frequency range that exhibits electro-optic properties such as the Pockels effect. The Pockels effect is the optical phenomenon in which the refractive index of a medium, such as lithium niobate, varies with an applied electric field. The varied refractive index of the lithium niobate may be used to provide switching. The applied electrical field is provided to present day electro-optical switches by external control circuitry.
Although the switching speeds of these types of devices are very fast, for example on the order of nanoseconds, one disadvantage with present day electro-optic switching devices is that these devices generally require relatively high voltages in order to switch optical beams. Consequently, the external circuits utilized to control present day electro-optical switches are usually specially fabricated to generate the high voltages and suffer from large amounts of power consumption. In addition, integration of these external high voltage control circuits with present day electro-optical switches is becoming an increasingly challenging task as device dimensions continue to scale down and circuit densities continue to increase. | {
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As methods effective for the prevention of tooth decay, there are several means known to date, such as (1) strengthening the acid resistance of teeth to render their constituents harder to elute in acid, which represents one of the direct causes of dental caries, and (2) facilitating the remineralization process on teeth to compensate for their eluted constituents at a higher rate.
Since fluoride acts to turn hydroxyapatite which is a major constituent of teeth into a fluoroapatite to render the constituent hard to elute in acids and is highly effective for facilitating the formation of hydroxyapatite to thereby facilitate the remineralization of teeth, it has become common at dental clinicals to coat teeth with a fluoride as treatment for preventing dental caries. In such cases, the most commonly used fluoride formulation is an acidulated phosphate fluoride solution (hereinafter referred to as APF).
However, the APF treatment takes a long time to complete the formation of calcium fluoride, because it includes a process which facilitates the double decomposition of teeth by the action of an acid and then exploits calcium contained there to produce calcium fluoride for fluoride uptake into the teeth. Specifically, for this method of treatment, it has been necessary that APF is first applied onto human teeth to be left as it is for 4 minutes, and further, the eating and/or drinking is forbidden for additional 30 minutes or longer. In this case, a person undergoing the care or treatment is required to exercise patience in keeping his or her mouth open for 4 minutes after APF application, and further, such a patient subjected to the treatment may feel rather burdensome because APF has a nasty taste due to its strongly acidic taste. Especially, for patients who are children, such a bad taste might be more burdensome.
On the other hand, as periodontal disease patients increase in number, dentin hyperesthesia caused by a stimulus occurring when eating and/or drinking something hot or cold and transferred directly to pulp nerves due to exposed dentin at dental roots has now become a problem to be seriously dealt with. To prevent or treat this dentin hyperesthesia, it is necessary to block the transmission of external stimulus by heat, acids, or etc. to pulp nerves by obturating dental canaliculi present in dentin.
While it has so far been done as preventive and curative treatment for dentin hyperesthesia to apply a 5% sodium fluoride varnish coating onto teeth, such application treatment is not free from problems yet, in that this method uses calcium contained in teeth and saliva to obturate the dental canaliculi and it takes time for calcium to turn to its fluoride and thus a longer time elapses before the dental canaliculi is effectively obturated, or in that the effect of the treatment has a low persistence after application (cf. the nonpatent literature 1.)
The patent literature 1 given below discloses a product for the remineralization of dental enamel, containing a first separate ingredient containing a water-soluble calcium salt, and a second separate ingredient containing a phosphate and at least one water-soluble fluoride salt that produces fluorine ions. However, the mineralization product disclosed in the patent literature 1 is taught to be “applied as a mixture prepared by mixing the first and second solutions together” (cf. the patent literature 1, page 19, lines 3 to 4).
In this regard, in a case where the first and the second liquids are first mixed together and then the resultant mixture is applied on to the teeth, there has been a problem that it is difficult to form calcium phosphates selectively on a tooth surface, because if the first solution containing a water-soluble calcium salt is mixed with the second solution comprising a phosphate and a water-soluble fluoride salt, such calcium phosphates (including partially fluorinated salts) are formed in the mixture during the course of mixing. Patent literature 1: JP-A-2001-523217 Nonpatent literature 1: “Tooth Wear and Dentin Hyperesthesia” translated by Kenichi Kobayashi, et al., p. 357, Ishiyaku Publishers, Inc., 2003
The present invention provides an oral cavity composition containing a first composition (A) and a second composition (B) given below, said first composition (A) and said second composition (B) being discretely packed from each other so that said two compositions can be alternately used and then come to be mixed with each other at each tooth region when applied thereto: (A) a first composition containing a fluoride ion supplying compound and an inorganic phosphoric acid or a salt thereof; and (B) a second composition containing a calcium salt of organic acid, wherein an organic acid constituting said calcium salt of organic acid has a pKa value ranging from 3 to 11, or at least one pKa value ranging from 3 to 11 when said organic acid has plural pKa values. | {
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As a direct current source used in electronic devices such as a cellar phone, a DC input DC output DC—DC converter, for example, is widely employed. A synchronous rectifying DC—DC converter of a step-down type hitherto known as a type of this DC—DC converter (which will be simply referred to as a DC—DC converter as well). The driver is constituted from a CMOS inverter for switching a power supply voltage (DC input voltage) Vcc. The filter circuit smoothes the output of the driver and outputs a preset desired DC voltage (set DC voltage), and a control circuit controls the CMOS inverter.
In the DC—DC converter of the configuration described above, other components except for the filter circuit are integrated into the circuit and manufactured as the semiconductor integrated circuit for the DC—DC converter.
In a semiconductor integrated circuit for the DC—DC converter, there is a problem that a parasitic transistor is created, so that the DC—DC converter malfunctions due to a parasitic current.
An example of a semiconductor integrated circuit for a negative step-up circuit used in nonvolatile semiconductor storage devices such as a flash EEPROM (Electrically Erasable and Programmable Read Only Memory) is disclosed in Patent Document 1, for example. The semiconductor integrated circuit serves to prevent creation of a parasitic NPN transistor, and as shown in FIG. 9, the semiconductor integrated circuit is configured using an NMOS-type transistor of a triple-well structure. A Deep-N-well 202 is formed on a P-type silicon wafer 201, a P-well 203 is formed on this Deep-N-well 202, and a Deep-N-well terminal 209 having a floating potential is formed over this Deep-N-well 202. An NMOS-type transistor M201 is formed over the P-well 203, and nodes N202 and N203 are also formed over the P-well 203. To the nodes N202 and N203, capacitances C201 and C202 are connected, respectively.
According to the semiconductor integrated circuit of the configuration as described above, the P-well 203 and the Deep-N-well 202 are separated. Thus, each of their potentials can be set to a specific potential or the floating potential. Thus, it is described that even if a parasitic NPN transistor Q201 is created, potentials of a base and a collector thereof become floating ones, so that even if a base current Ib flows from the P-well 203 to the node N202 due to a step-up operation, a constant collector current Ie is not generated, and the parasitic NPN transistor Q201 can be thereby made to be ineffective.
[Patent Document 1]
JP Patent Kokai Publication No. JP-P2001-43690A | {
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} |
Various control schemes are known to sense and diagnose a failure in a refrigeration unit. However, most such schemes can continue to operate the unit only if the failed component is not a critical input or output component of if there is an alternative component that can substitute for the failed one. Component redundancy increases the complexity as well as the cost of the control.
In U.S. Pat. No. 4,327,556, failure of the defrost heater in a refrigerator to cycle is detected by a microprocessor. In response to a failed heater, the microprocessor connects an override relay in circuit with the heater to cycle the heater on and off. This system, however, cannot continue to operate a refrigerator upon a failure of critical input components, such as a food compartment temperature sensor or temperature setting control, or upon a failure of any critical output component, such as a damper, that otherwise would result in spoilage of food.
In another type of refrigeration system, an internal diagnostics routine executed by a microprocessor tests the condition of a temperature sensor in the refrigerator. In response to a fault, i.e., an open circuited or short circuited sensor, the compressor is cycled on and off with a predetermined duty cycle to cool the fresh food and freezer compartments of the refrigerator. This system, although effective to prevent spoilage of food caused by a failed temperature sensor, is not capable of adequately preserving food in the event of other types of component failures, such as a failed baffle, or in the event of multiple component failures, such as a short-circuited temperature sensor and a stuck baffle occurring at the same time.
An object of this invention accordingly is to provide a method of and system for controlling a refrigerator to accommodate the failure of what is usually considered to be an essential input or output device in a manner that continues to preserve the food being stored.
Another more specific object of the invention is to provide a method of and system for detecting the failure of a baffle of a refrigerator and in response operating the refrigerator in a manner to continue to suitably preserve food.
A further object of the invention is to provide a method of and system for detecting multiple component failures in a refrigeration control, identifying the components failed and operating the refrigerator using non-failed components to continue to preserve food.
Another object is to provide an improved system for diagnosing failed critical components of a refrigerator, taking corrective action to continue to preserve food and generating an alarm to identify to service personnel the nature of the failure diagnosed.
An additional object is to provide a microprocessor implemented control for a refrigerator that diagnoses failed critical input and output components of the refrigerator and in response carries out control using non-failed components to continue to preserve food.
A still further object of the invention is to provide fault tolerant control of an appliance without requiring component redundancy.
There is a tendency for control components within a refrigerator to be exposed to sources of electrical noise and to develop internal noise as a result of thermal effects and deterioration over time. Failure diagnosis systems of the prior art have a tendency to misinterpret noise superimposed on a component as a valid signal having a particular instantaneous value and in response take inappropriate action.
A further object of the invention, therefore, is to provide in a refrigerator control system a method of and system for detecting a "noisy" control component.
A still further object is to provide a method of and system for controlling a refrigerator in a manner to continue to preserve food stored therein upon diagnosis of a "noisy" critical control component. | {
"pile_set_name": "USPTO Backgrounds"
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Networks have enhanced our ability to communicate and access information by allowing one personal computer to communicate over a network (or network connection) with another personal computer and/or other networking devices, using electronic messages. When transferring an electronic message between personal computers or networking devices, the electronic message will often pass through a protocol stack that performs operations on the data within the electronic message (e.g., packetizing, routing, flow control).
Internet Protocol Security (IPsec) is a protocol suite for securing Internet Protocol (IP) communications by authenticating and encrypting each IP packet of a communication session. IPsec can include protocols for establishing mutual authentication between agents at the beginning of the session and negotiation of cryptographic keys to be used during the session. In addition, IPsec can be used in protecting data flows between a pair of hosts (host-to-host), between a pair of security gateways (network-to-network), or between a security gateway and a host (network-to-host).
Internet Protocol security (IPsec) uses cryptographic security services to protect communications over Internet Protocol (IP) networks. IPsec can support network-level peer authentication, data origin authentication, data integrity, data confidentiality (encryption), and replay protection. | {
"pile_set_name": "USPTO Backgrounds"
} |
1. Field
Example embodiments relate generally to a touch panel sensor. More particularly, embodiments of the inventive concept relate to a capacitive touch panel sensor, and a touch panel display device having the same.
2. Description of the Related Art
A mobile device (e.g., a smart-phone) mostly includes a touch panel sensor according to a mobile convergence trend. The touch panel sensor may be classified into a capacitive touch panel sensor, a resistive touch panel sensor, a light sensing touch panel sensor, etc. Recently, the capacitive touch panel sensor that detects capacitance changes caused by a touch of an external electric conductor, such as a finger, is widely used as the touch panel sensor.
Generally, the capacitive touch panel sensor is coupled to a display device (e.g., over the display device or under the display device). In addition, the capacitive touch panel sensor performs a sensor driving operation in synchronization with the display device. Thus, a display driving operation that is performed by the display device may change (i.e., may influence) capacitance between transmitting (TX) electrodes and receiving (RX) electrodes of the capacitive touch panel sensor. As a result, touch sensitivity of the capacitive touch panel sensor may be degraded. | {
"pile_set_name": "USPTO Backgrounds"
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Generally described, user computing devices may facilitate the playback or display of items of content, such as audiobooks, electronic books, songs, videos, television programs, computer and video games, multi-media content, and the like. For example, an electronic book reader computing device (“e-reader”) may display an electronic book on a screen and/or play an audiobook through speakers or headphones.
In some instances, a user may be interested in consuming multiple items of content at the same time. For example, a user may wish to read an electronic book while listening to an audiobook of the same title, such as The Adventures of Tom Sawyer. The electronic book and the audiobook (or more generally, any group of two or more items of content related to the same content title) may be referred to as “companion” items of content.
However, in many current approaches, the user must manually line up the two companion items of content so that the words narrated in the audiobook correspond to what the user is reading in the electronic book. For example, the user may find it necessary to pause the audiobook manually during portions of the electronic book that have no counterpart in the audiobook. Likewise, the user may find it necessary to manually fast-forward the audiobook during portions of the audiobook that have no counterpart in the electronic book. This scheme can prove frustrating and inconvenient for users. | {
"pile_set_name": "USPTO Backgrounds"
} |
1. Field of the Invention
The present invention relates generally to semiconductor integrated circuit devices, and more specifically to output driver devices.
2. Description of the Prior Art
As is well known, a phenomenon known as power supply line noise inductance effects can significantly decrease the potential output performance of an integrated circuit device. This phenomena, which results from the inductance on various signal lines both on chip and from chip to package, is proportional to both the inductance and to the rate of change of the current with respect to time (di/dt), and causes the output signal and the power supply lines to oscillate or bounce.
Since the output of the chip is not output until the power supply lines have settled down, the power supply line noise inductance has the effect of slowing down the potential output performance of an integrated circuit device. Many different design techniques have been developed in an attempt to limit di/dt and simultaneously increase the output performance of the chip.
A common approach to this problem is to limit the di/dt for all output drivers. Limiting di/dt both allows the power supply line to stabilize faster and increases the amount of time taken by an output driver to change states. However, with appropriate di/dt limiting, this tradeoff can still result in a decrease in the access time at the output pins of the integrated circuit package, which is an increase in device performance.
Limiting di/dt has been accomplished by several methods. One method is to add resistors to the power supply lines of the output transistors or the stage driving the output transistors. The resistors uniformly reduce the rate of switching of the output drivers. Another method to limit di/dt is to use an output driver designed to drive the load with a constant di/dt. Another approach is to provide power buses for the output drivers which are separate from the rest of the circuit.
It is known that the outputs at the output pins of the integrated circuit package do not all change state at the same time. Since the chip cannot be validly accessed until the slowest output pin is ready, a wait time exists between the time at which the fastest output pin changes state and the time at which the slowest output pin changes state.
Currently available methods for di/dt limiting increase device operating speed by minimizing power supply oscillations, but the methods do not attempt to reduce the wait time. Thus, overall device operating speed is less than the theoretical maximum speed.
It would be desirable to increase device operating speed beyond that currently achievable through the reduction of the power supply oscillation settling time without suffering wait time delays to the extent of the prior art. | {
"pile_set_name": "USPTO Backgrounds"
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In the manufacture of printed circuit boards in the electronics industry there is a need for an ink for marking printed circuit boards and electronic components which will not be removed by the solvent baths and vapor degreasers used to clean the completed printed circuit boards in the final stages of manufacture. At the present time the only inks which do this are (1) Thermosetting inks or (2) Epoxy inks.
The thermosetting inks are satisfactory for individual components which are designed to stand the baking temperatures but not for marking on assembled printed circuit boards where there are also components which will not stand the baking temperatures. The epoxy inks must be mixed at the time of use and have a pot life usually of less than one hour. They also require periods of more than an hour to harden to the point the printed circuit boards may be handled without smearing the ink. Epoxy inks also do not stand extended solvent vapor degreaser action with good predictability. They may come off some surfaces and stick on others. It is desirable also that there be a method of removing the ink without destroying other markings on the component or printed circuit boards.
In hospitals and chemical laboratories there is a need for an ink for bottles and specimens which will not be attacked or dissolved by organic solvents in the bottles or used in processing. | {
"pile_set_name": "USPTO Backgrounds"
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