The present invention is directed to lubricating oils exhibiting improved resistance to oxidation and deposit/sludge formation comprising a lubricant base oil and catalytic antioxidants comprising an effective amount of a) one or more polymetal organometallic compound; and, b) effective amounts of one or more substituted N,N′-diaryl-o-phenylenediamine compounds or c) one or more hindered phenol compounds or both, to a method for improving the antioxidancy and the resistance to deposit/sludge formation of formulated lubricating oil compositions by the addition thereto of an effective amount of the aforementioned catalytic antioxidants, and to an additive concentrate containing the aforementioned catalytic antioxidants.

Oxidation causes buildup of particulate matter in lubricating oils. This buildup thickens the lubricating oil and causes deposits in engine parts. When the level gets too high, the increase in viscosity results in poor lubrication and an inefficient operation of the engine system. Such inefficiencies result in loss of fuel economy and increased exhaust emissions.
Currently, lubricating oil formulations are rendered resistant to oxidative degradation by the addition to the lubricating oil formulations of free radical scavenger antioxidants such as sterically hindered phenols, hindered amines and mixtures thereof and hydroperoxide decomposers such as zinc dialkyldithiophosphate.
Most of such antioxidants as are presently used are consumed by the oxidation promoters in the oil (the prooxidants) on a stoichiometric basis. Antioxidants can be added to lubricating oil formulations only in limited quantities and consequently even if and when the maximum practical amount is added they are quickly consumed and disappear, with the undefended oil rapidly oxidizing with their disappearance.
Other antioxidants such as copper acetylacetonates, while consuming the prooxidants on a more than stoichiometric basis are still themselves used-up at a rate of less than about 10:1 and therefore, while superior to the phenolic and aminic antioxidants are still not sufficiently long lived or suitable for the next generation of extended drain lube oils or sealed for life/filled for life lubricant environments.
Prooxidants are continuously generated in the lubricant during routine use or added/introduced into the oil by blow-by gases, or exhaust gas recirculation as during the operation of internal combustion engines.
U.S. Pat. No. 4,867,890 teaches oil soluble organo copper compounds as antioxidants. U.S. Pat. No. 5,650,381 teaches a lubricating oil composition which contains from about 100 to 400 ppm of molybdenum from a molybdenum compound which is substantially free of active sulfur and about 750 to 5,000 ppm of a secondary diaryl amine, which provide improved oxidation control and friction modifier performance. U.S. Pat. No. 6,121,211 teaches a lubricating oil composition comprising a base oil of lubricating viscosity and at least one thiocarbamate containing a divalent metal and a sludge preventing and seal protecting amount of at least one aldehyde or epoxide or mixture thereof. JP 53024957 teaches the liquid phase oxidation of cyclohexane into cyclohexanol by oxidizing the cyclohexane with an oxygen containing gas in the liquid phase in the presence of metal salts selected from the group consisting of Cr, V and W of an organic acid or a chelate compound as a catalyst.
U.S. Pat. No. 4,766,228 teaches a metal dihydrocarbyldithiophosphoryl dithiophosphate material containing a metal selected from zinc, cadmium, lead and antimony or an oxygen and/or sulfur-containing molybdenum complex useful as a lubricant additive (see also U.S. Pat. No. 4,882,446). U.S. Pat. No. 5,439,604 teaches compositions containing metal salts of polyalkenyl substituted monounsaturated mono- or dicarboxylic acids which may be used as a compatibilizing material for mixtures of dispersants, detergents, anti-wear and antioxidant materials. U.S. Pat. No. 3,707,498 teaches antioxidant additives comprising a mixture of a metal dialkyldithiocarbamate and a tertiaryalkyl primary amine, where the metal is from Group IIb, IVa and Va.
U.S. Pat. No. 3,351,647 teaches a composition useful as an oil additive that functions as an antioxidant and antiwear agent having the general formula:
wherein R is a substantially hydrocarbon radical; M is a metal selected from the group consisting of zinc, calcium, copper, nickel, cobalt, chromium, lead, and cadmium; A, B and C are radicals selected from the class consisting of hydrogen and substantially hydrocarbon radicals; x is the valence of M; y is from about 0.5 to about 6. U.S. Pat. No. 4,427,560 teaches a formulation containing among other additives an oxidation inhibitor. The oxidation inhibitors comprising sulfur bridge, bis hindered phenols effectively limit or prevent the attack of oxidants on copper/lead metal and preferably comprise bis(dithiobenzyl) metal derivatives having the formula:

U.S. Pat. No. 3,764,534 teaches a composition comprising a lubricating oil and at least one thioorganometallic complex of the formula:
in which M is selected from the transition metals and zinc, cadmium, tin, lead, antimony and bismuth; n is the oxidation degree of M, R1 and R2 are each a monovalent hydrocarbon radical having one to 20 carbon atoms and 0 to 3 heteroatoms selected from the group consisting of halogen, oxygen, sulfur and nitrogen; Y is selected from the hydrogen atom and the radicals R′, R′O, R′S and R′CO in which R′ is a hydrocarbon radical of 1 to 20 carbon atoms; Y and R1 or R2 may form a divalent hydrocarbon radical containing 1 to 20 carbon atoms and 0-3 heteroatoms selected form oxygen, sulfur and nitrogen; and each atom Z is oxygen or sulfur, at least one of the 2n atoms Z being sulfur. It is recited that these materials exhibit high antioxidancy activity even at high temperature. They can be used with base oils of petroleum origin as well as with synthetic base oils. See also GB 1,322,699.
GB 1,358,961 teaches that 9,10-dihydroanthracene acts synergistically with certain metal β-diketone complexes to provide antioxidancy. The metal β-diketone complexes are of the formulaM(-O—CR1═CR2—CR3═O)n wherein M is a metal, n is 2 or 3, R2 is hydrogen or an alkyl group having 1 to 20 carbon atoms and R1 and R3 are alkyl, aryl or alkoxy groups having 1-10 carbons. U.S. Pat. No. 4,849,123 teaches drivetrain fluids comprising oil soluble transition metal compounds which address low temperature thickening of automatic transmission fluids (ATFs) and high temperature thickening or gear oils. When used in combination with zinc dialkyl dithiophosphates, the quantity of metal compound in the ATFs or gear lubricants is important to obtaining the combination of antioxidant and antiwear properties needed for the extended life of the fluids.
U.S. Pat. No. 4,705,641 teaches the combination of copper and molybdenum salts as being an effective antioxidant and antiwear additive for hydrocarbons such as lube oils. The copper salt preferably is selected from the group of carboxylates consisting of oleates, stearates, naphthenates and mixtures thereof and the molybdenum salt preferably is selected from the group of carboxylates consisting of naphthenates, oleates, stearates and mixtures thereof.
U.S. Pat. No. 4,122,033 discloses an oxidation inhibitor and a method for using the oxidation inhibitor for hydrocarbon materials, particularly lube oils. One or more transition metal containing compounds can be utilized in combination with one or more peroxide decomposer compounds selected from aliphatic amines, alkyl selenides, alkyl phosphines and phosphates wherein the aliphatic and alkyl portions of said compound each contain from about 1 to about 50 carbon atoms as oxidation inhibitors in organic compositions subject to auto-oxidation. Among the transition metal compounds useful according to the patent are the salts of scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, yttrium, zirconium, niobium, molybdenum, tellurium, ruthenium, rhodium, palladium, and silver, to mention a few.
U.S. Pat. No. 5,631,212 teaches an engine oil of improved wear resistance and antioxidancy comprising base oil, an oil soluble copper salt, an oil soluble molybdenum salt, a Group II metal salicylate and a borated polyalkenyl succinimide. Molybdenum salts are the oil soluble salts of synthetic or natural organic acids, preferably C4 to C30 saturated and unsaturated fatty acids, e.g., molynaphthanate, molyhexanate, molyoleate, molyxanthate and molytallate.
U.S. Pat. No. 4,066,561 teaches organometallic complexes of the formula:
wherein, as defined in the patent, n is an integer of from 1 to about 10, preferably from 1 to about 5; A is an aromatic moiety, preferably phenyl or naphthyl; M is a polyvalent metal, such as, for example, Be, Mg, Ca, Ba, Mn, Co, Ni, Pd, Cu, Zn and Cd; X is a radical selected from the group consisting of organophosphoro, organocarboxyl, organoamino, organosulfonyl, organothio, organooxy, nitrate, nitrite, phosphate, sulfate, sulfonate, oxide, hydroxide, carbonate, sulfite, fluoride, chloride, bromide and iodide; R1 and R2 are alkyl of from 1 to about 10 carbon atoms, aryl, hydrogen,
or a combination thereof; R′ is alkyl of from 1 to about 10 carbon atoms, aryl or hydrogen; R3, R4, R5 and R6 are hydrogen, alkyl of from 1 to about 200 carbon atoms, aryl, alkyl-substituted aryl where the alkyl substituent is comprised of form 1 to about 200 carbon amounts, carboxyaryl, carbonylaryl, aminoaryl, mercaptoaryl, halogenoaryl or combinations thereof. The metal complexes reportedly stabilize the lubricant to which they are added against oxidation.
U.S. Pat. No. 5,824,627 teaches a lube oil composition containing a major amount of a lube base oil and a minor amount of an additive having the formula M4-yMOyS4LnQz and mixtures thereof, wherein M is a metal selected from Cr, Mn, Fe, Co, Ni, Cu, and W, L is independently selected organic groups selected from dithiophosphates, thioxanthates, phosphates, dithiocarbamates, thio-phosphates and xanthates, having a sufficient number of carbon atoms to render the additive soluble or dispersible in the oil, and Q is a neutral electron donating compound, y is 1 to 3, n is 2 to 6, and z is zero to 4, and the L provide a total charge sufficient to neutralize the charge on the M4-yMOyS4 core.
U.S. Pat. No. 3,649,660 teaches silylorganometallocenes as being useful antioxidants for organopolysiloxane fluids. The silylorganometallocenes are selected from the class of    (a) polymers having structural units of the formula
    (b) copolymers composed of structural units of the formula
and at least one unit of (a), and    (c) disiloxanes of the formula
where R is a monovalent hydrocarbon radical, R″ is a divalent hydrocarbon radical, and (C5Q4)M(C5Q5) is an organometallocene, where Q is selected from hydrogen, an electron donating organic radical, and an electron withdrawing organic radical and M is a transition metal, a is a whole number equal from 0 to 2 and b is a whole number equal from 0 to 3.
Transition metal is defined to include all metals of Group III to VIII of the Periodic Table capable of forming a π complex with a cyclopentadienyl radical to form a metallocene. The transition metals that are operative in the present invention are, for example, metals having atomic numbers 22 to 28, 40 to 46, and 71 to 78, such as titanium, vanadium, chromium, manganese, iron, cobalt, nickel, zirconium, columbium, molybdenum, technetium, ruthenium, rhodium, palladium, hafnium, tantalum, tungsten, rhenium, osmium, iridium and platinum (see also U.S. Pat. No. 3,745,129).
U.S. Pat. No. 5,015,402 teaches basic metal and multi-metal dihydrocarbyl-phosphorodithioates and phosphoromonothioates as antioxidant additives. These materials are represented by the general formula:[Z]d[RO)2PSS]yMaXb  (I)wherein M and X represent different metal cations selected from the group consisting of zinc, copper, chromium, iron, copper, manganese, calcium, barium, lead, antimony, tin and aluminum; Z is an anion selected from oxygen, hydroxide and carbonate; R is independently a linear or branched alkyl group of 1 to about 200 carbon atoms, or a substituted or unsubstituted aryl group of 6 to about 50 carbon atoms; a and b are integers of at least one and are dependent upon the respective oxidation states of M and X; y is a whole integer which is dependent upon the oxidation states of M and X; and d is an integer of 1 or 2.
As a consequence of more stringent and demanding performance and environmental requirements on lubricating oils, for example fill for life oils, sealed bearings oils and greases, or modern extended drain engine lubricating oils to perform better, for longer periods and under more severe conditions of temperature and load over longer times as manifested by current and future lubricating oil specifications, particularly engine oil classifications for diesel lubricants (PC7 and PC8) and passenger car lubricants (GF-3 and GF-4), more efficient, longer lasting and more robust antioxidants are required for use in the lubricants. Increased performance results in improved fuel economy and reduced exhaust emissions in engine systems, e.g., gasoline engine systems and diesel fuel engine systems, where the diesel fuel has a sulfur content ranging in the amount of about 5-1,000 ppm.

ExxonMobil Research and Engineering Company


An assisting suspension arrangement for suspending a monitoring device, comprising a hook member, a blocking member, and a resilient member is disclosed. The suspension arrangement is configured to adopt an open state and a closed state. The suspension arrangement is configured such that when the monitoring device is suspended by the suspension arrangement, the hook member is adapted to carry the weight of the monitoring device and thereby to move toward the open state; and such that when the load of the weight of the monitoring device is released from the hook member, the resilient member is adapted to move the hook member toward the closed state. A monitoring device comprising such a suspension arrangement is also disclosed.

A suspension arrangement may be used in various applications for providing suspension of devices such as equipment, fixtures or decorations. The suspension may be temporary, such as when moving a piece of equipment by a crane, or permanent such as when installing a lamp by suspending it in a ceiling.
One type of suspension arrangement is adapted for suspending a monitoring device. The monitoring device may be a surveillance camera adapted for outdoor mounting. The monitoring device may be attached to a mounting bracket, which in turn is fixed to a wall or roof structure. The installation of such a monitoring device, which can be large and heavy, may be facilitated by first attaching the monitoring device to the mounting bracket such that the monitoring device is suspended and can hang on its own. An assisting suspension arrangement may be used for this purpose. The suspension arrangement may be integrated on a top surface of the monitoring device's housing.
The suspension arrangement may comprise a hook member attached to the monitoring device. The hook member may be configured to receive a safety wire with a loop extending from the mounting bracket. Thereby the monitoring device can hang on its own while the person installing the monitoring device, also referred to as the monitoring device fitter, connects necessary cables between the monitoring device and the mounting bracket.
When the monitoring device is connected as required, the monitoring device may be fixedly attached to the mounting bracket by screws or the like. The suspension arrangement need not be detached and may function as a safety arrangement if the primary attachment fails or is actively removed. An example of such a suspension arrangement may be seen in the appended FIG. 1.
The suspension arrangement may be equipped with a leaf spring for preventing unintentional unhooking of the safety wire from the hook member. The hook member may be configured to be arranged in an open position for receiving the wire by depressing the leaf spring so as to create a gap, between the leaf spring and the hook member. The safety wire is passed through the gap. It may be relatively easy to hook onto the safety wire, but the small gap obtainable by depressing the leaf spring can make unhooking difficult. Tests also show that in some situations the hook member may break, for example because the safety wire hooks onto a part of the leaf spring instead of the hook.
From the above discussion, there is evidently a need for improvement of existing suspension arrangements which are suitable for suspending a monitoring device.

Suspension arrangement, and a monitoring device having a suspension arrangement


Methods and apparatus to monitor media exposure in vehicles are disclosed. An example implementation includes collecting audience measurement data with a media monitoring device fixed in a vehicle and transmitting the audience measurement data from the media monitoring device to a shuttle located within the vehicle, the shuttle being incapable of collecting audience measurement data independent of the media monitoring device.

Determining size, demographics, and media exposure and/or consumption patterns of a media audience helps media providers to understand their audience and better tailor their media content. Further, accurate media exposure demographics allow advertisers to target media content to audiences of a desired size and/or audiences comprising members having a set of common desired characteristics (e.g., income level, lifestyles, interests, etc.) associated with typical buyers of the advertised product or service.
In order to collect demographics of audiences, an audience measurement company may enlist a number of media utilizing households and/or consumers (e.g., panelists) to cooperate in an audience measurement study for a period of time. The media usage habits of these panelists, as well as demographic data about these panelists, are collected using automated and/or manual collection methods. The collected data is subsequently used to generate informational statistics related to media exposure, including, for example, audience sizes, audience demographics, audience preferences, the total number of hours of media exposed per audience member and/or per region, program ratings, etc.
Traditional audience measurement systems have employed a client/server architecture wherein the client (e.g., a metering device) and server (e.g., a data collection unit to collect data from the metering device) are in different physical locations. For example, in a typical system, the client is located near an audience member being monitored (e.g., attached to or otherwise in proximity to a television, included in a portable device carried by the audience member, etc.). The server is typically located at an off-site location that is away from the client (e.g., a central office of an audience measurement company such as the Nielsen Company, etc.) The client typically collects audience measurement data and transmits the same to the server. The server then analyzes audience measurement data from a number of panelists to identify ratings, trends, etc.


A variable gain amplifier is disclosed, comprising a pair of differential MOS transistors M1 and M2 and a current mirror. The sources of the differential MOS transistors M1 and M2 are connected to a constant voltage terminal. Since a DC voltage Vc is added to input signals, output signals that are theoretically free of a distortion are obtained. The gain can be controlled from infinitesimal. Since the gain is directly proportional to the control voltage, it can be easily controlled. Since a single output current is free of a distortion, even if amplifiers are connected on many stages, an output signal that is free of a distortion can be obtained.

1. Field of the Invention
The present invention relates to a variable gain amplifying circuit for processing an analog signal in a MOS type semiconductor integrated circuit.
2. Description of the Related Art
In recent years, as digital units have been widely used and digital signal processing technologies have been advanced, CMOS type integrated circuits suitable for processing digital signals have shared most part of integrated circuits in the semiconductor market.
However, since video signals and audio signals are inputted and outputted as analog signals, they can be easily processed as analog signals. When such signals are processed as digital signals, analog circuits are required for an A/D converter, a D/A converter, filters, an oscillator for a clock signal, and so forth.
A bipolar type integrated circuit is suitable for an analog circuit. A CMOS type integrated circuit is not suitable for an analog circuit except for part of circuits such as an analog switch and a sample hold circuit. However, the fabrication process for a bipolar type integrated circuit and a Bi-CMOS type integrated circuit is relatively expensive. In addition, it is desired to structure one chip CMOS type integrated circuit that has both a digital circuit and an analog circuit. Thus, CMOS type integrated circuits that process analog signals have been intensively developed.
A circuit that is frequently used and that largely affects the performance of a final product is a "variable gain amplifier". As a bipolar type integrated circuit, a hybrid transistor circuit named "gain cell" has been used. When a variable gain amplifier is structured with such a "gain cell", a circuit that has a gain proportional to the ratio of two bias currents can be easily accomplished.
When a variable gain amplifier is structured with a CMOS type integrated circuit, if the bipolar type integrated circuit is substituted with a CMOS type integrated circuit or a modification circuit, a large secondary distortion always takes place. FIG. 9 shows the structure of a variable gain differential amplifier composed of a CMOS type integrated circuit that is disclosed in Japanese Patent Laid-Open Application No. 8-298416. Next, with reference to the CMOS type variable gain differential amplifier, problems of the conventional circuit will be described.
The circuit shown in FIG. 9 comprises a first differential transistor circuit and a second differential transistor circuit. The first differential transistor circuit is composed of MOS transistors M1 and M2 and a current source I1. Likewise, the second differential transistor circuit is composed of MOS transistors M3 and M4 and a current source I2. In each of the first differential transistor circuit and the second differential transistor circuit, a pair of source coupled transistors are biased with a current source. Next, the first differential transistor circuit composed of the MOS transistors M1 and M2 and the current source I1 will be described. However, for simplicity, it is assumed that input signals are fully-differential signals, both the transistors operate in a saturation region (pinch-off region) and that a short channel effect is not considered.
At this point, the characteristic of each MOS transistor can be represented with a principal parameter k and a threshold voltage Vth as follows. EQU I=(k/2)(VGS-Vth).sup.2
where k is a constant represented by .mu.CoxW/L (W represents the gate width; L represents the gate length; Cox represents the gate capacitance; .mu. represents the carrier mobility of channel). With the formula, the operations of the MOS transistors M1 and M2 are expressed as follows. EQU M1:I11=(k/2)(VGS1-Vth).sup.2 (1) EQU M2:I12=(k/2)(VGS2-Vth).sup.2 (2)
When Eq. (1)-Eq. (2) is calculated, the following result is obtained. ##EQU1## where VGS1 represents the gate-source voltage of the MOS transistor M1; VGS2 represents the gate-source voltage of the MOS transistor M2; and Vin represents the differential input voltage. Since it is assumed that input signals are fully-differential signals, when the mid-point voltage of the input signals is denoted by VB, the input voltages supplied to the input terminals are expressed by VB+Vin/2 and VB-Vin/2.
The source voltage VA of the differential transistor pair is calculated as follows. EQU VGS1=VB+Vin/2-VA EQU VGS2=VB-Vin/2-VA
Thus, assuming that VB-VA-Vth=A, by adding Eq. (1) +Eq. (2), ##EQU2## Substituting the above expressions into Eq. (3), the trans-conductance Gm1 [=(I11-I12)/Vin] can be obtained as follows. ##EQU3## Likewise, the trans-conductance Gm2 [=(I21-I22)/Vin] of the second differential transistor circuit composed of the MOS transistors M3 and M4 and the current source I2 is obtained as follows. ##EQU4## However, it is assumed that the parameter k and the threshold voltage Vth for the MOS transistors M3 and M4 are the same as those for the MOS transistors M1 and M2. Since the output signals with reverse polarities of the two differential transistor circuits are connected, the resultant trans-conductance Gm is obtained by the difference between Eq. (5) and Eq. (6). ##EQU5## As is clear from Eq. (7), the trans-conductance Gm dynamically varies corresponding to an instantaneous amplitude value Vin of the input signals. In other words, the output signals have a distortion. Since the trans-conductance Gm includes a square term of the differential input voltage Vin, the distortion in the output signals is mainly a secondary distortion. With a load that is a linear device such as a resistor or a load that is an MOS transistor with a secondary characteristic, the secondary distortion cannot be canceled. In this case, the distortion of the waveform is very complicated. When a variable gain amplifier is structured with CMOS transistors, a large distortion inevitably takes place and thereby, the quality of the output signal deteriorates.


A substrate processing chamber component demonstrates reduced erosion in an energized gas. The component has a ceramic structure composed of aluminum oxide with a surface exposed to the energized gas in the chamber. The erosion of the surface by the energized gas is substantially reduced by erosion resistant properties of the ceramic structure, which arise from a ratio of the total area of the grains GSA to the total area of the grain boundary regions GBSA in the ceramic structure of from about 0.25 to about 2.5. Also, at least about 80% of the grains in the ceramic structure have a grain size in the range of from about 1 micron to about 20 microns. The ceramic structure also has a purity of at least about 99.8% by weight to further reduce erosion of the surface.

Embodiments of the present invention relate to substrate processing chamber components that exhibit resistance to erosion.
In the processing of substrates, such as semiconductor wafers and displays, a substrate is placed in a process chamber and exposed to an energized gas to deposit or etch material on the substrate. During these processes, process residues are generated and deposited on internal surfaces in the chamber. For example, in chemical vapor deposition processes, deposition material can deposit on component surfaces in the chamber, such as on deposition rings and shadow rings. In subsequent process cycles, the deposited process residues "flake off" from the chamber component surfaces to fall upon and contaminate the substrate. Consequently, the deposited process residues are periodically cleaned from the chamber surfaces.
However, the exposed surfaces of the chamber components are often eroded during the cleaning processes or when exposed to other erosive gases. For example, during a dry-cleaning process, the components may be exposed to energized halogenated cleaning gases, such as NF3 or CF4, that can rapidly erode the component surfaces. The cleaning gases are typically activated by microwaves or RF energy. Other erosive gases, such as for example etching gases, can also undesirably erode the surfaces of the chamber components. Erosion of the chamber components is undesirable, as particles of the eroded component often flake off from the component and fall upon and contaminate the substrates being processed in the chamber.
In one version, the erosion resistance of the components is improved by providing components comprising an erosion-resistant ceramic material, such as for example, aluminum oxide. Ceramic materials such as aluminum oxide typically exhibit good resistance to erosion in energized gases, and can reduce the generation of particles in the chamber. For example, U.S. Pat. No. 6,083,451 to Gupta et al., describes an alumina ceramic material that is resistant to fluorine-containing plasma. However, even these materials do not provide sufficiently good results, as the ceramic materials can still become eroded by some gas formulations. When they do get eroded, the components can typically be cleaned and re-used in the chamber only a few times before they become too eroded for use and need to be replaced, a practice that can be both costly and result in downtime of the processing apparatus.
The chamber components can also be eroded by chemical solutions that are used to clean the components. Wet cleaning processes can use harsh cleaning chemicals, such as for example solutions comprising hydrofluoric acid, are sometimes used to clean process residues having compositions that are compositionally hard or otherwise difficult to clean. The surfaces of the chamber components are easily excessively eroded by such cleaning solutions, requiring the frequent replacement of the component.
Thus, there is a need for chamber components having improved resistance to erosion by energized gases, such as for example etching and cleaning gases, and cleaning solutions. There is a further need for such erosion resistant components to be made of ceramic materials, and methods of manufacturing such components.

Erosion resistant process chamber components


A home office communication system (10) has a control and display system (16). A modem (12) is controlled by the control and display system (16) and connected to a telephone line (14). A multiplexer (18) is connected to the modem (12) and multiplexes a plurality of outgoing data streams in a predefined format and demultiplexes an incoming data stream from the modem (12). A speech encoding system (20) generates a plurality of speech packets to form one of the plurality of outgoing data streams. A telephone line control system (22) generates a plurality of control packets forming one of the plurality of outgoing data streams and an information channel (24) forms one of the plurality of outgoing data streams.

An executive working from home or his hotel room, commonly needs to communicate with his office. This can include calling for voice mail messages, downloading email messages, receiving faxes and talking to his coworkers. In addition, the executive may need to download files from the company's project server. Commonly it will require a separate call to get the voice mail messages, email messages, faxes and telephone conversations. In addition, these telephone call may each be long distance telephone calls.
Thus there exists a need for a home office communication system that does not require multiple telephone calls to receive voice mail messages, email messages, faxes and telephone conversations.

Home office communication system and method


Process for the separation of a mixture comprising at least one hydrofluoroalkane and hydrogen fluoride, according to which a hydrofluoroalkane/hydrogen fluoride mixture is reacted with at least one chlorinated or chlorofluorinated precursor of the hydrofluoroalkane. Process for the preparation of a hydrofluoroalkane comprising such a separation, in combination with a catalytic reaction stage. Azeotropic compositions.

Hydrofluoroalkanes can be prepared by reaction of an appropriate chlorinated precursor with hydrogen fluoride, as disclosed, for example, in Patent Applications EP-A1-0,699,649 and WO-A1-97/15540 (on behalf of Solvay) and in Patent Application WO-A1-97/05089. In such a process, at the outlet of the reactor, the mixture of reaction products comprises, in addition to the desired hydrofluoroalkane, hydrogen chloride originating from the removal of the chlorine atom or atoms from the starting chlorinated precursor, hydrogen fluoride, chlorofluorinated intermediates, generally unconverted chlorinated precursor, possibly inert diluents, and various byproducts in small amounts. Given that the operation is usually carried out with an excess of hydrogen fluoride with respect to the chlorinated precursor, unconverted hydrogen fluoride is generally present in the mixture of reaction products. Whereas the majority of the constituents of the mixture of reaction products can be easily and completely separated by distillation, complete separation between the hydrofluoroalkane and the hydrogen fluoride is generally very difficult to achieve by distillation, this being because these compounds often form azeotropic mixtures.
Patent Application WO-A1-97/05089 discloses a process for the purification of hydro(chloro)fluoroalkanes (in particular 1,1,1,3,3-pentafluoropropane or HFC-245fa) from azeotropic mixtures with hydrogen fluoride by an azeotropic distillation technique comprising two successive stages of distillation at different temperatures and at different pressures.
However, this azeotropic distillation technique exhibits the disadvantages of requiring a large difference in temperature or in pressure between the two columns, so as to have available a sufficient separation potential (difference in composition between the low pressure/temperature azeotrope and the high pressure/temperature azeotrope), and of producing a high recycling flow rate between the two columns.
Patent Application WO-A1-97/13719 discloses a process for the separation and recovery of hydrogen fluoride from its (azeotropic) mixtures with, inter alia, hydrofluoroalkanes comprising from 1 to 6 carbon atoms (in particular HFC-245fa). The mixture is brought into contact with an alkali metal fluoride (in particular, potassium fluoride or caesium fluoride) solution and the organic phase is separated from the phase comprising the hydrogen fluoride and the alkali metal fluoride.
Through this known process, contamination of the organic phase by the potassium fluoride or caesium fluoride and the risk of decomposition of the hydrofluoroalkanes which this contamination might bring about may be feared. Moreover, these alkali metal fluorides, and more particularly caesium fluoride, are very expensive.


A packing element for mass transfer column or towers and/or heat transfer columns or towers through which a gas and/or a liquid flows, is provided herein. The packing element possesses a plurality of exchange surfaces. The exchange surfaces of the packing element are formed by the surfaces of half-wave-shaped strips or wave-shaped strips. The packing element also possesses at least one first group of strips containing at least one half-wave-shaped strip or wave-shaped strip having a first periodic length, and at least one second group of strips adjoining thereto and containing at least one half-wave-shaped or wave-shaped strip having a second periodic length. Preferably, at least one outer side of the packing element is formed as a boundary element joining at least some of the strips of a group of strips.

(i) Field of the Invention
The invention relates to a packing element for mass transfer or heat transfer columns or towers through which a gas and/or a liquid flows.
(ii) Description of the Prior Art
Such packing elements are known and are used in systematically structured packings in mass transfer and/or heat transfer columns, especially in such columns operated according to the counter-current principle, e.g., distillation, rectification or absorption towers. In such applications, the packing elements consist of lamellae arranged vertically in the direction of flow, the packing element possessing undulations or folds oriented at an angle to the direction of flow. In the packed state, the lamellae of adjacent packing elements intersect and are in contact with each other.
EP 0 158 917 describes a packing element which possesses narrow slits, regularly arranged in each case on the flanks of the undulations or folds, while the edges of the peaks and valleys of the undulations and folds are left unslit. The purpose of this design is to achieve a uniform, and thus optimum, distribution of the counter-current flowing media, and thus to obtain an optimum exchange of media. These known packing elements are effective and create little loss in pressure. However, they possess the disadvantage that this type of packing element, with its regularly arranged slits, is relatively expensive to manufacture.
EP 0 130 745 describes a packing element that can be manufactured from expanded material, which is expanded after the slits have been cut in it. However, such slits then open up disadvantageously in a non-uniform manner. When undulations and folds are subsequently formed in the packing elements, some of the slits are positioned on the peaks or valleys of the undulations or folds, which again results in further irregular opening of the slits. This disadvantageously results in non-uniform distribution of the gas and/or liquid flows. Instead, the flows are arbitrarily distributed and locally different pressure losses occur. In addition, the geometry of the exchange surfaces formed by the surfaces of the packing elements undergoes continual change.

Packing element for mass transfer heat transfer columns


The invention relates to an electrical connector comprising, a female terminal, including a terminal base body; one or more pairs of terminal plates facing each other, protruding in an insertion direction from the edge of the terminal base body, for receiving and connecting to a mating male terminal and the one or more pairs of terminal plates facing each other being adapted to form recesses for receiving the mating male terminal and to provide a clamping compressive force against the mating male terminal; and one or more tilting restriction elements, a connector cavity for building the female terminal in, and an opening of the electrical connector for inserting a mating male terminal for connecting the mating male terminal with the female terminal, wherein the connector cavity includes one or more contacting portions corresponding to the tilting restriction elements.

Technical Field of the Invention
The invention relates to an electrical connector with the female terminal movable inside the electrical connector cavity and a motor with such an electrical connector.
Brief Description of the Related Art
Electrical connectors have been developed for the motor industry. In the motor industry an electrical connector that comprises a female terminal inside a connector housing is used. Such a connector housing is sometimes integrally formed with a motor cover or a brush holder plate and therefore a female terminal is built into the connector housing portion of a motor cover or a brush holder plate. Terminals may be made from conductive metal, such as copper. Technical norms require that the female connector should be able to move inside the electrical connector cavity in all directions, to allow the expansion of the female terminal, particularly because the female terminal spreads out when the female terminal receives the mating male terminal or because the female terminal is swollen when temperature increases. This ensures, in turn, less friction oxidation on the point where the female terminal contacts the electrical connector cavity.
The patent publication U.S. Patent Application Publication No. 2012/0129407 describes an electrical connector for connecting to a male blade terminal. The electrical connector comprises a female terminal including one or more pairs of opposing beams for compressing against the male blade terminal. Clamping means are provided. However this patent publication does not disclose any feature that the female terminal inside the electrical connector cavity does not always contact any part of the side wall of the electrical connector cavity and therefore the female connector is movable inside the electrical connector cavity. Such a feature can avoid friction oxidation of the female terminal especially when the mating male terminal is inserted into the female terminal.
In case the electrical connector cavity is large but the terminal is too small, the female terminal is movable inside the electrical connector cavity and tilts inside the electrical connector cavity and can avoid friction oxidation of the female terminal when the mating male terminal is inserted into the female terminal. However due to too much space in the electrical connector cavity, the female terminal can be misaligned from the opening of the electrical connector where the mating male terminal is inserted into. The terminals can be damaged when the mating terminal is inserted.
One solution is making the electrical connector cavity smaller in order to reduce the female terminal movement. However, the smaller electrical connector cavity creates an interference condition when the mating male terminal is inserted into the female terminal, and the female terminal expands outward, and the expanded female terminal prevents the female terminal from moving inside the electrical connector cavity. This increases the risk of friction oxidation.
An object of the present invention is to provide an improved electrical connector with a female terminal which can keep the female terminal movable inside an electrical connector cavity.
Another object of the present invention is to provide an electrical connector with a female terminal which has durability against the pressure at the time of insertion of the mating male terminal into the female terminal.
Still another object of the present invention is to provide for an electrical motor having such an electrical connector with a female terminal.

Electrical connector with female terminal and motor with such an electrical connector


The conventional holding mechanism for foldable side rails have such problems that the release lever can be accidentally pressed for release action and that if a double lock is employed for preventing it, automatic holding action cannot be performed.

Various rails have been proposed as side rails of beds. Among them, a conventional technique of foldable side rails that have plural stanchion members pivotally rotatably connected between an upper horizontal rail member and a lower horizontal rail member, to form a parallel link mechanism, wherein a holding mechanism is provided for keeping the stanchion members erect is described, for example, in Japanese Patent No. 3029026.
In the foldable side rails described in the patent document, the holding mechanism is provided at an end of the upper horizontal rail member and comprises a mechanism support member connected with the stanchion member provided at the end; the mechanism support member has a stopper pin set biased in the advancing direction by a spring; the stanchion member has a fitting hole capable of having the stopper pin set fitted in it when the stanchion member is kept erect; a release action site for allowing the stopper pin set to recede against the force of the spring is provided directly at the rear of the stopper pin set; and the bottom side of the release action site is exposed downward from the bottom of the mechanism support member. Further, the mechanism support member has a lock member capable of being moved between the release preventing position and the release allowing position for the release action site.
In the above constitution, when the stanchion members are kept erect, with the tip of the stopper pin set fitted in the fitting hole, the side rails have the upper horizontal rail member kept at the highest position in the state of use. In this constitution, a slope face for allowing the stopper pin set to slide on it is formed near the fitting hole, so that when the horizontal rail members are raised to keep the stanchion members erect, the stopper pin set can be automatically fitted into the fitting hole.
In the case where the lock member is set at the release preventing position with the stopper pin set fitted in the fitting hole, even if the release action site exposed downward from the bottom of the mechanism support member is accidentally touched to apply a force in the release allowing direction, the release action site is prevented from moving by the lock member and cannot move. Therefore, the tip of the stopper pin set remains fitted in the fitting hole, and the stanchion members and the horizontal rail members are kept in the state of use safely.
The conventional foldable side rails as described above have the following disadvantages.
1. The release action site provided of the stopper pin set is exposed downward from the bottom of the mechanism support member. So, if a force in the release allowing direction is applied owing to an accidental touch in the case where the lock member is not set at the release preventing position, it can dangerously happen that the stopper pin set is disengaged from the fitting hole and that the stanchion members fall while the upper horizontal rail member drops.
2. In the stowed state where the stanchion members fall while the upper horizontal rail member is kept at the lowest position, if the lock member is moved to the release preventing position and the horizontal rail members are raised to keep the stanchion members erect, then the stopper pin set is kept projected to interfere with the stanchion member having the fitting hole. Therefore, the stopper pin set cannot be automatically fitted into the fitting hole.
The object of this invention is to solve the above problems.

Holding mechanism for foldable side rails

Abstract: This invention proposes a holding mechanism for foldable side rails, characterized in that the holding mechanism 4 is provided at an end of an upper horizontal rail member 1u and comprises a mechanism support member 5 connected with the stanchion member provided at said end; the mechanism support member 5 has a stopper pin set 12 capable of advancing and receding; the stopper pin set 12 is biased in the advancing direction by a spring 13; the stanchion member has a fitting hole 10 allowing the stopper pin set 12 to be fitted in it when the stanchion member is kept erect; the mechanism support member further has a release lever 6 engaged with a mechanically driven trigger site 15 provided in connection with the stopper pin set for making the stopper pin set recede against the force of the spring; a play mechanism is provided between the release lever and the mechanically driven trigger site; and the mechanism support member further has a release prevention mechanism for preventing the movement of the release lever in the release allowing direction.


Statistical pattern recognition relies on substantial amount of annotated samples for better learning and learning is insufficient in low resource scenarios. Creating annotated databases itself is a challenging task, requires lot of effort and cost, which may not always be feasible. Such challenges are addressed by the present disclosure by generating synthetic samples through automatic transformation using Deep Autoencoders (DAE). An autoencoder is trained using all possible combination of pairs between a plurality of classes that could be formed from a limited number of handful samples in a low resource database, and then the DAE is used to generate new samples when one class samples are given as input to the autoencoder. Again, the system of the present disclosure can be configured to generate number of training samples as required. Also, the deep autoencoder can be dynamically configured to meet requirements.

Statistical machine learning systems require enough samples for its better learning and often face problem of under training, mainly due to lack of samples in training dataset. Creating a comprehensive training dataset involves human efforts, time and cost. In addition to that, sometimes, even if enough samples exist, the machine learning systems fail to learn class information properly, mostly because of non-representativeness of the samples over the class information space.

Automatic generation of synthetic samples using dynamic deep autoencoders


A semiconductor device according to embodiments includes: a first conductivity-type first semiconductor layer set to a first potential; a second conductivity-type second semiconductor layer stacked on the first semiconductor layer and set to a second potential; an interlayer insulating film disposed on a main surface of the second semiconductor layer; a resistor disposed above the first semiconductor layer while interposing the second semiconductor layer and the interlayer insulating film therebetween; and a terminal electrically connected to the second semiconductor layer.

In a semiconductor device in which a semiconductor integrated circuit is formed on a semiconductor substrate, a high voltage generated inside the semiconductor device is sometimes used for the semiconductor integrated circuit. For example, in a semiconductor device including a nonvolatile semiconductor storage element, a high voltage ranging approximately from 10 V to 35 V is generated in the semiconductor device during an operation thereof. Under a condition where such a high voltage is used, a resistor having a high resistance value and a high withstand voltage is used. In order to obtain a stable output, it is necessary that the resistance value of the resistor to which the high voltage is applied be stable.


An apparatus that combines the functionality of a walker with that of a single crutch is herein disclosed. The apparatus provides for one crutch that comes up from the side support of the walker and thus the side of the user's body and is adjustable in height, as is the walker support handles, such that the invention can be customized for any sized user. The adjustment is facilitated by use of spring pin slip fittings, and thus can be adjusted in a matter of minutes without tools. The crutch support can be easily moved from the right to left hand side of the walker by use of a removable clamp system. It is also envisioned that certain models of the invention can provide crutches on both the right and left hand side of the walker simultaneously, based upon the needs of the patient. When not in use or not needed, the invention folds up in a manner similar to a conventional walker thus providing a low profile for ease of storage.

Walkers are used everyday by the elderly, the disabled, and those recovering from surgery or illness. Walkers assist with ambulation and mobility, while providing independence and safety to the user. The usage of a walker requires that the user have use of both of their arms in order to move and place the walker with each step. Should the usage of one arm not be available, a person with limited ambulation is typically forced to utilize a wheelchair, which while providing some mobility, limits independence and may lengthen recovery time due to the lack of exercise associated with walking with a walker. Accordingly, there is a need for a means by which the heath benefits, mobility and independence associated with a walker can be provided to those users who have limited or no use of one arm or both arms. The development of the invention herein described fulfills this need.
U.S. Pat. No. D 535,220 issued to Wu discloses a walker with arm handles. This design patent does not appear to disclose a crutch walker that has a similar design to the instant invention nor does it appear to disclose an apparatus that supports a user by the axillary region of the body.
U.S. Pat. No. D 437,679 issued to Lisowski et al. discloses an adjustable walker cane. This design patent does not appear to disclose a crutch walker that has a similar design to the instant invention nor does it appear to disclose a walker with a crutch attachment.
U.S. Pat. No. 5,411,044 issued to Andolfi discloses a patient transfer walker which provides a crutch like support and a walker with wheels. It does not appear that this patent discloses a unitary walker embodiment with a crutch mechanism that is adaptable to one or both sides of the walker utilizing the mechanism disclosed herein. It also appears that the referenced patent discloses an apparatus that has its object the transfer of a user from the standing to seated position.
U.S. Pat. No. 4,993,446 issued to Yarbrough discloses a combination walker and crutch which appears to be two crutches joined together to form a walker. This patent does not appear to disclose a walker with a crutch attachment on the upper surface of the walker nor does it appear to disclose an apparatus capable of employing a crutch that can be utilized by only one side of a user.
U.S. Pat. No. 4,830,035 issued to Liu discloses a seesawly-controlled foldable walker. This patent does not appear to disclose a walker with a crutch attachment that can be employed on one side or both sides to assist a user in ambulation.
U.S. Pat. No. 4,748,994 issued to Schultz discloses a reversible walker device which appears to be a walker with handles to control the movement of the walker. This patent does not appear to disclose a device that possesses crutch attachment(s) to assist a user in support while ambulating.
U.S. Pat. No. 4,251,105 issued to Barker discloses a mobility aid. This patent does not appear to disclose a walker with crutch attachment to assist in supporting users while ambulating with the walker.
U.S. Pat. No. 4,248,256 issued to Thomas discloses a platform crutch attachment for an invalid walker. This patent does not appear to disclose a crutch attachment that supports a user by the axillary area of the user.
U.S. Pat. No. 3,625,237 issued to Wertz discloses an arm support for invalid walkers. This patent does not appear to disclose a crutch walker that supports a user by the axillary area of the user.
U.S. Pat. No. 2,796,916 issued to Womble discloses a folding walking aid. This patent does not appear to disclose a crutch walker with the ability to provide different configurations with respect to the crutch position nor does it appear to disclose a crutch attachment with two supports.
U.S. Pat. No. 2,759,525 issued to Ries discloses a multiple purpose invalid walker. This patent does not appear to disclose a crutch walker with the ability to provide different configurations with respect to the crutch position nor does it appear to disclose a crutch attachment with two supports.
The prior art appears to disclose various apparatus that support users while ambulating utilizing walkers, some of which provide support for the upper extremities. The prior art does not appear to describe a crutch walker with the ability to conform to user deficit in the upper extremities in the manner specified by the instant invention nor does the prior art appear to provide the upper body support that the instant invention possesses.

Crutch walker and associated use therefor


An encoder 13 determines the remaining travel distance of a stacker crane to perform deceleration control. When a linear sensor 8 determines an absolute distance from the stop position, the linear sensor 8 performs deceleration control, and when a mark sensor 26 detects a mark 36, the mark sensor 26 performs stop control. Likewise, deceleration control is performed based on the remaining elevation distance determined by an encoder 19. When a linear sensor 9 determines an absolute distance from the stop position, the linear sensor 9 performs deceleration control, and when the mark sensor 26 detects the mark 36, the mark sensor 26 performs stop control.

In operating a movable object such as a stacker crane or a hand of a robot, it is necessary to stop the movable object correctly and swiftly at a large number of stop positions. In this regard, according to the disclosure of Japanese Laid Open Patent Publication No. 3-267206, a mark is provided at each shelf of an automated warehouse, and a sensor of the stacker crane recognizes the mark. Stop data for stopping the stacker crane at each shelf is stored in a memory. However, if there is any change in a drive-train over time such as abrasion of travel wheels, or if deformation of the shelf occurs, it is not possible to stop the movable object at a correct position using the stop data stored in the memory. Therefore, there is a demand for the control which makes it possible to stop the movable object correctly and swiftly at the stop position even if there is any change over time on the moveable body side or on the stop position side.


A circuit for combining and dividing a high frequency power including a first transmission line connected between a first port and a third port, a second transmission line connected between a second port and the third port, and a circuit section having one end connected between the first port and the first transmission line and the other end connected between the second port and the second transmission line, the circuit section including a resistor and at least one capacitor connected in series.

The present invention relates generally to a circuit for combining and dividing high frequency power, and more particularly to a microwave power combiner/divider for use in a microwave communication apparatus, etc.
There is known a power combiner/divider for use in a microwave band, which comprises as a basic structure a so-called Wilkinson type power combiner/divider circuit. This circuit is advantageous in that the circuit configuration is simple and it has an impedance conversion function. By virtue of the advantage, this power combiner/divider circuit is widely used, for example, as an output matching circuit in a high output power amplifier.
FIG. 1 shows an equivalent circuit of a conventional Wilkinson type power combiner/divider.
As is shown in FIG. 1, one end of a first transmission line 11 is used as a first signal port (division port) 21, and one end of a second transmission line 12 is used as a second signal port (division port) 22.
The other end of the first transmission line 11 and the other end of the second transmission line 12 are connected at a third signal port (combining port) 23. The first signal port 21 and second signal port 22 are connected via a resistor (isolation resistor) 31.
The length of each of the first and second transmission lines 11 and 12 is set at about 1/4 of the wavelength of the input signal. The characteristic impedance of each transmission line 11, 12 and the value of the resistor 31 are determined by the impedances of the first to third signal ports 21, 22 and 23.
It is known that the characteristic impedance should ideally be set at (2R.sub.L .multidot.R.sub.g).sup.1/2 and the resistance at 2R.sub.L in the case of a circuit wherein the impedances of the first and second signal ports 21 and 22 (division ports) and the impedance of the third port 23 (combining port) are set at R.sub.L and R.sub.g respectively and a signal input from the third signal port 23 is divided into equal-level signals to the first and second signal ports 21 and 22.
When the circuit shown in FIG. 1 is actually used, power amplifier circuits, for example, are connected to the first and second signal ports 21 and 22. As a matter of course, when such amplifier circuits are connected, the first signal port 21 and second signal port 22 need to be disposed away from each other at a predetermined distance.
Although the resistor connected between the first signal port 21 and second signal port 22 should ideally be a lumped-parameter device, as mentioned above, the resistor is influenced by a parasitic element occurring due to the increased distance between the first and second signal ports 21 and 22.
FIG. 2 shows an equivalent circuit in a case where there is a distance between the first and second signal ports 21 and 22.
In the circuit diagram, the influence of the parasitic element at the resistor can be expressed by transmission lines 32 and 33 connected to the resistor 31. Suppose that in the equivalent circuit of the power combiner/divider circuit, as shown in FIG. 2, microstrip lines are provided on a GaAs semi-insulative substrate with a thickness of 30 .mu.m, and the distance between the first signal port (division port) 21 and second signal port (division port) 22 is 530 .mu.m and the width of each microstrip line (i.e. first and second transmission lines 11 and 12) is 150 .mu.m. In this case, two wiring elements having a length of 190 .mu.m are needed to connect the resistor 31. FIG. 3 shows a simulation result, in which a parasitic effect in this case is taken into account.
The abscissa in FIG. 3 indicates the frequency (GHz) and the ordinate indicates the isolation and return loss (dB). The center frequency is 29.5 GHz, the impedance of each of the division ports (first and second signal ports) and that of the combining port (third signal port) are respectively 3.OMEGA. and 50.OMEGA., and the isolation resistance of 6.OMEGA. is connected to the microstrip lines with a width of 20 .mu.m.
As is understood in FIG. 3, the return loss and isolation of the division port, which can be obtained, are at most about 7 dB at the center frequency.
As has been described above, the effect of the resistor itself is considerably deteriorated by the addition of the parasitic element to the resistor portion, and the isolation between the first signal port 21 and second signal port 22 is degraded.

High frequency power divider and high frequency power combiner


A semiconductor integrated circuit device with a built-in photosensor is provided with a light shielding aluminum film which is formed on a whole surface of the semiconductor integrated circuit device continuously to prevent faulty operation of the semiconductor integrated circuit because of incident light. In order to reduce parasitic capacity generated between a light shielding aluminum film and a wiring for transmitting a high-frequency signal or other elements whereto a high-frequency signal is applied, a light shielding aluminum film is partially removed on the wiring and other elements as well as a photosensor and a pad.

1. Field of the Invention
The present invention relates to a semiconductor integrated circuit device with a built-in photosensor (referred to as "IC with a built-in photosensor" hereinafter), and more particularly relates to techniques for improving electric characteristics of the IC with a built-in photosensor.
2. Description of the Background Art
A frequency of an analogue signal which is employed in an IC for a compact disk player to detect a light signal has been about 5 MHz. Recently, however, a request for processing a high-frequency signal of 20 MHz is increasing, particularly in an IC for a laser disk. Consequently, it is necessary to improve frequency characteristics of an IC with a built-in photosensor to a high-frequency signal. A conventional IC device with a built-in photosensor will be described with reference to FIG. 8. FIG. 8 is a plan view of a chip of an IC with a built-in photosensor employed in an IC for an optical pickup of a compact disk player and the like.
In the figure, numeral 1 denotes a light shielding aluminum film, numeral 2 denotes a pad for connecting a lead wire, numerals 3, 4 denote photosensors for detecting light. In the conventional IC device with a built-in photosensor, the whole chip except the photosensors 3, 4 for sensing light and the pad 2 is shielded from light with the light shielding aluminum film 1 to prevent faulty operation of a circuit because of an incident light.
Next, an outline of part of an integrated circuit for processing light signals detected by the photosensor 3 of the IC device with a built-in photosensor shown in FIG. 8 will be described with reference to FIG. 9. FIG. 9 is a block diagram showing a structure of an integrated circuit for processing a signal detected by a photosensor. In the figure, numeral 5 denotes a wiring, one end of which is connected to an output end of the photosensor 3, for transmitting a signal detected by the photosensor 3, numeral 6 denotes a capacitor, which is connected to the other end of the wiring 5, and a signal detected by the photosensor 3 is applied thereto, numeral 7 denotes a current-voltage converter circuit, an input end of which is connected to the wiring 5, for converting a signal detected by the photosensor 3 into a voltage, numeral 8 denotes a wiring for transmitting a signal passing through the capacitor, numeral 9 denotes a high-frequency amplifier for processing a high-frequency signal detected by the photosensor 3, numeral 10 denotes a wiring for transmitting a signal from the photosensor 4 and B1 through B8 denote signal processing blocks for processing an output signal from the photosensors 3, 4; B1 through B4 denote blocks for detecting a signal outputted from the photosensor 3, B5 denotes a high pass filter which passes only high-frequency signals among signals detected by the photosensor 3, B6 denotes a block for processing a high-frequency signal and B7 and B8 denote blocks for detecting if the photosensor 4 senses light. Accordingly, a high-frequency signal outputted from the photosensor is inputted to the high-frequency amplifier 9 passing through the wiring 5, the capacitor 6 and the wiring 8.
FIG. 10 is an enlarged view of the photosensor 3 and its vicinities. In FIG. 10, numeral 11 denotes a pad for connecting the photosensor 3 and the wiring 5. FIG. 11 is a perspective view taken along the lines C--C of FIG. 10 observed in the direction of the arrows. In FIG. 11, numeral 1 denotes a conductive light shielding film, numeral 15 denotes a layer insulating film and k1 denotes a peripheral region of the wiring 5. Other identical numerals with FIG. 8 indicate the same or corresponding parts of FIG. 8. As shown in the figure, parasitic capacity is generated between the wiring 5 and the aluminum light shielding film 1 in the region k1.
Generally, an overlapping portion of conductive layers, such as the conductive light shielding film 1 and the wiring 5 with the layer insulating film 15 in between shown in FIG. 12, can be regarded as equivalent to a parallel-plate capacitor consisting of two parallel conductive plates 20 shown in FIG. 13. Assuming the symbol C represents capacity of this capacitor, the symbol .epsilon..sub.r the relative dielectric constant of a substance in between two flat plates 20, the symbol d the distance between two flat plates 20, the symbol S the area of the flat plate 20 and the symbol .epsilon..sub.O the dielectric constant of vacuum, the following relation holds: EQU C=.epsilon..sub.O .multidot..epsilon..sub.r .multidot.S/d (1)
Accordingly, when the area wherein parasitic capacity can be generated becomes larger by employing a relatively large capacitor, long wiring or the like, parasitic capacity increases, so that the influence becomes great.
Next, FIG. 14 is a sectional view of a capacitor formed on a substrate. In the figure, numeral 21 denotes an aluminum electrode, numeral 22 denotes an N type semiconductor diffused layer, numeral 23 denotes a P type semiconductor diffused layer, numeral 24 denotes a nitride film, numeral 25 denotes an epitaxial growth layer and other identical numerals with FIG. 11 indicate the same or corresponding parts of FIG. 11. Parasitic capacity is generated at a region k2 where the aluminum electrode 21 and the light shielding aluminum film 1 are facing each other in this capacitor.
Since the conventional semiconductor integrated circuit device is structured as mentioned above, the light shielding aluminum film 1 covering over the whole chip generates parasitic capacity between itself and an element such as a wiring or a capacitor formed thereunder, as shown in FIG. 12. Particularly, since the high-frequency amplifier 9 formed in the IC is an amplifier for a light signal picked up by the photosensor 3 and the input impedance of the high-frequency amplifier 9 is high-impedance, there is the disadvantage that circuit characteristics such as frequency characteristics or the like are greatly deteriorated by the parasitic capacity in a line connected to an input end of the high-frequency amplifier 9.


A light source is disclosed for use an optical printer illuminating a spatial light modulator to efficiently and uniformly project light onto a photosensitive medium while providing a simpler design of the spatial light modulator in the optical printer. The light source uses light emitting diodes opposed across a light pipe. The light from the light emitting diodes propagates in the light pipe until striking a redirection structure which redirects the light out of lateral surface of the light pipe.

The present invention relates generally to electro-photographic printing and film recording apparatus, such as light emitting optical printers. More particularly, the invention relates to an efficient light emitting diode ("LED") light geometry for printing images optically by exposing a photosensitive recording medium to a light generated by light emitting diodes where the light is redirected substantially transverse to an axis of the light emitting diodes.
Optical printers make use of a variety of exposure devices such as lasers, spatial light modulators, and cathode ray tubes. All have been applied to expose photographic film as the photosensitive medium. FIG. 1 shows a prior art optical design with a light source 2 which can be any one of the aforementioned light generating devices. Light 3 is projected from the light source 2 in a conical shape where the edges of the cone have an angle .theta. relative to a central axis 9. The cone passes through a lens 4 where the central axis 9 is also the center of the lens 4 such that the cone is inverted through a spatial light modulator("SLM"), also known as a liquid crystal display, panel 5. The light 3 then passes through a projection lens 6 and is imaged onto a photosensitive medium 7. This optical system is well known in the art to have a problem in that the light has an intensity distribution over the photosensitive medium 7 according to a cos.sup.4 .theta. function. The distribution is shown in a graph 8 where the highest intensity of the light 3 is along the central axis 9 and quickly falls off towards the edges of the photosensitive medium 7. This non-uniform light distribution detrimentally affects the printed output since the image appears darker toward the edges of the photosensitive medium.
A further problem that is encountered with standard light sources 2 is with respect to the SLM panel 5. Conventional printhead designs use an SLM panel 5 that is row and column addressable and therefore each of the pixels in the SLM panel 5 are selectively turned on or turned off as is required for the particular image at any given time. A problem with this type of design is that the SLM panel 5 itself has to have electronics that can control a row and column addressing scheme for each individual pixel. As SLM panel designs get more complex, currently on the order of 1 million pixels per SLM panel, this addressing is taking up more and more valuable space on the SLM panel 5 and is becoming more and more complex. A further problem with such a design is that SLM panels are susceptible to leakage, where a pixel that is in an off state still allows some light to leak through, thereby decreasing a contrast ratio between neighboring pixels.
Another problem with conventional light sources is that, in practice, the actual radiation pattern is not the conical shape 3 that was previously described. The conical shape is a common approximation but the actual radiation pattern is an elliptical shape. Therefore, radiation projected outside the conical shape 3, which was described in the conventional optical system, is lost as unusable light, thereby decreasing the efficiency of the light source. Also, if the cone angle through the SLM is made large to increase light efficiency, then the contrast ratio of SLM will decrease.
The conventional optical system shown in FIG. 1 also illustrates another problem with currently available light sources. The light sources generally must be fixed behind a lens 4 at a distance that allows the light 3 to optimally project through the lens 4. Requiring such a distance makes the optical design more spaced out, which takes up valuable space within a printer.
Accordingly, it is an object of this invention to provide a light source for an optical printer that is compact to decrease required space within an optical printer.
It is another object of this invention to provide a light source that illuminates efficiently and uniformly so as to optimize printed output out of the optical printer.
It is still another object of the invention to simplify printhead design to allow use of less complex SLM panels in the optical printer.
It is a further object of the invention to increase contrast ratio between neighboring pixels to allow the optical printer to project sharper images onto the photosensitive medium.
These and other objects of the invention will be obvious and will appear hereinafter.

Efficient LED light geometry for optical printers


An ink set is used in one or more recording media selected from a non-ink-absorbing or low ink-absorbing medium, a medium having an arithmetic surface roughness Ra of 20 μm or more, fabric, and plain paper. The ink set contains a glitter ink which is recorded by an ink jet head and contains a glitter pigment and a polymerizable ink which contains an active energy ray polymerizable compound and does not substantially contain a coloring material.

1. Technical Field
The present invention relates to an ink jet recording method, a recorded material, and an ink set.
2. Related Art
In recent years, there has been an increase in demand for recorded materials in which an image having glitter is formed on a recording surface. As a method for forming an image having glitter, recoding has been performed heretofore using, for example, a foil stamping method including preparing a recording medium having a recording surface with high flatness, and then pressing a metallic foil against the recording medium, a method including vacuum depositing metal or the like onto a plastic film having a smooth recording surface, a method including applying a glitter pigment ink to a recording medium, and further performing press processing, and the like.
As an ink containing a glitter pigment (hereinafter referred to as a glitter ink as appropriate) and an ink jet recording method, JP-A-2008-174712 discloses one in which solvents which slightly melt a base material which is a non-absorbing material are used for an ink composition. In the case of such solvents, it has been possible to obtain good glitter in polyvinyl chloride plastic as the non-absorbing material. However, when non-absorbing materials or materials having remarkably low absorbency, such as plastic, metal, and glass with extremely low solubility, are not provided with an ink receiving layer, a solvent and the like convect before the ink dries, so that the surface smoothness of the glitter pigment is lost, which causes problems, such as deterioration of gloss. Even in the case of absorbing materials, when a glitter pigment is recorded by an ink jet method on a recording medium whose surface smoothness is not sufficient, such as plain paper, or a pigment layer whose surface is not smooth and which contains a pigment having an average particle size (average particle size based on a volume, the same applies in the following description) of 200 μm or more, light is irregularly reflected due to insufficient smoothness of the glitter pigment, and therefore it has been difficult to obtain good glitter. When recording is performed on non-absorbing materials or materials having remarkably low absorbency, there has also been a problem in that the adhesiveness of the glitter pigment to the recording medium is not sufficient, so that good friction resistance is not obtained.

This patent is subject to a terminal disclaimer.

Ink jet recording method, recorded material, and ink set


The invention provides a display device having a thin film transistor and a storage capacitor storing a display signal applied to a pixel electrode through this thin film transistor on a substrate, where dielectric strength between electrodes forming the storage capacitor is enhanced for increasing the yield. In the storage capacitor, a lower storage capacitor electrode, a thin lower storage capacitor film, a polysilicon layer, an upper storage capacitor film and an upper storage capacitor electrode are layered. The polysilicon layer is formed by crystallization by laser annealing. The polysilicon layer of the storage capacitor is microcrystalline and thus the flatness of its surface is enhanced. The pattern of the polysilicon layer (storage capacitor electrode) is formed larger than the bottom portion of an opening, and the edge of its peripheral portion is located on a buffer film on the slant portion of the opening or on the buffer film on the outside of the opening.

1. Field of the Invention
The invention relates to a display device having a thin film transistor and a storage capacitor storing a display signal applied to a pixel electrode through this thin film transistor on a substrate and a method of manufacturing the same.
2. Description of the Related Art
An active matrix type liquid crystal display device has a pixel selecting thin film transistor (hereafter, referred to as a "pixel TFT") in each of a plurality of pixels disposed into a matrix on a glass substrate. It also has a storage capacitor formed for storing a display signal applied to a pixel electrode through the pixel TFT.
This liquid crystal display device and a method of manufacturing the device will be described referring to FIG. 5. A light-shielding metal layer 11 as a light-shielding layer made of molybdenum, chromium, or the like for blocking external light incident on a first substrate 10 is formed on a first substrate 10 in a pixel TFT portion. This light-shielding metal layer 11 prevents a light leakage current caused by light entering a pixel TFT 100T. Then, a buffer film 53 made of an insulation film such as a silicon oxide film, a silicon nitride film or the like is formed over the light-shielding metal layer 11 by, for example, PE-CVD (Plasma Enhanced Chemical Vapor Deposition). An amorphous silicon layer is then formed on the buffer film 53. The amorphous silicon layer is then crystallized by laser annealing to form a polysilicon layer 55. The polysilicon layer 55 is etched into an island-like pattern. The polysilicon layer 55 functions as an active layer of the pixel TFT 100T and a storage capacitor electrode in a storage capacitor 100C.
Then, a gate insulation film 56 made of a silicon oxide film or the like is formed over the polysilicon layer 55 by PE-CVD. This gate insulation film 56 serves as a storage capacitor film 56C in the storage capacitor 100C.
Then, a gate electrode 57 made of molybdenum, chromium or the like is formed on the gate insulation film 56 of the pixel TFT 100T. On the storage capacitor film 56C, an upper capacitor electrode 58 made of the same metal as that of the gate electrode 57 is formed. An impurity is then ion-implanted in the polysilicon layer 55 using the gate electrode 57 and the upper capacitor electrode 58 as a mask to form a source and a drain. This impurity is phosphorus or arsenic for an N-channel type thin film transistor. A region between the source and the drain serves as a channel.
Then, an interlayer insulation film 19 is formed over the gate electrode 57 and the upper capacitor electrode 58. Contact holes CH1 and CH2 are provided in the gate insulation film 56 and the interlayer insulation film 19, and a drain electrode 20D and a source electrode 20S are formed through these contact holes CH1 and CH2, being connected with the polysilicon layer 55. Then, according to needs, a passivation film 21 made of a silicon nitride film or the like and a planarization film 22 made of a photosensitive material or the like are formed over the source electrode 20S and the drain electrode 20D. A contact hole CH3 is provided in the passivation film 21 and the planarization film 22, and a pixel electrode 23 made of transparent metal such as ITO (Indium Tin Oxide) or the like is formed through the contact hole CH3, being connected with the source electrode 20S.
Furthermore, a second substrate 30 made of a transparent material such as glass is attached to the first substrate 10, sealing a liquid crystal layer LC. A common electrode 31 made of transparent metal such as ITO is formed on the second substrate 30, being opposed to the pixel electrode 23. A polarizing plate (not shown) is formed on the first substrate 10 and the second substrate 30.
An operation of this display device is as follows. When the pixel TFT 100T turns on in response to a pixel selection signal applied to the gate electrode 57, the alignment of the liquid crystal molecules of the liquid crystal layer LC is controlled in response to a display signal applied to the pixel electrode 23 through the source electrode 20S. At this time, the display signal is applied to the pixel electrode 23 for a predetermined period by being stored in the storage capacitor 100C. In this manner, a transmission amount of light from a backlight BL in a pixel is controlled, thereby making a black or white display. The relevant technology is described in Japanese Patent Application Publication No. Hei 11-111998.
When the polysilicon layer 55 having crystal grain size of 300 to 400 nm is formed by crystallizing the amorphous silicon layer by laser annealing, protrusions occur in a polysilicon grain boundary portion on the surface of the polysilicon layer 55, of which the height is twice the thickness of the polysilicon layer 55. These protrusions cause degradation of the coverage of the storage capacitor film 56C layered on the storage capacitor electrode and reduce dielectric strength between the polysilicon layer 55 (the storage capacitor electrode) and the upper storage capacitor electrode 58, and the yield may reduce. When the polysilicon layer 55 is formed under the condition of enhancing the flatness of the surface, the crystal grain size is reduced and thus the resistance of the storage capacitor electrode is increased. This increases contact resistance between the thin film transistor and the storage capacitor, and the yield may reduce.

Display device and method of manufacturing the same


An external cavity laser has a mirror-based resonant tunable filter, such as a Fabry Perot tunable filter or Gires-Tournois interferometer tuning element, with the tunable filter being preferably used as a laser cavity mirror. A mirror-based resonant tunable filter is selected in which the spectral response in reflection has an angular dependence. A tilt scheme is used whereby by selecting an appropriate angle between the filter's nominal optical axis and the cavity optical axis, a narrowband peak spectral reflection is provided to the laser cavity. This tunable narrowband spectral reflection from the filter is used to lock and tune the laser output wavelength.

Temperature tuning is one of the most common approaches for controlling the wavelength of semiconductors lasers. This is a relatively simple technique to implement since the semiconductor laser chips are often mounted on thermoelectric coolers. By varying the drive current to a chip's cooler in response to a thermistor signal, for example, the output wavelength from the semiconductor laser chip can be stabilized or modulated.
The problem with temperature tuning is its range limitations. The lasers can usually only be tuned over a relatively small range of a few nanometers. As a result, temperature tuning finds limited application to telecommunications systems or spectroscopy applications in which only a small spectral band is to be accessed.
When wider tuning ranges are required, external cavity laser (ECL) configurations are more common. Semiconductor ECL systems usually combine a semiconductor gain chip and an external tuning element that provides wavelength selective feedback into the semiconductor chip.
Most commonly the semiconductor gain chip used in these ECLs is an edge emitting semiconductor optical amplifier (SOA). Either reflective SOAs, in which one of the facets is coated for reflectivity, or more conventional SOAs, in which both facets of the SOA are antireflection (AR) coated, can be used. These coatings prevent the chip from lasing on its own facet's feedback, allowing for the creation of the external cavity configuration in which the spectral makeup of the feedback is controlled by the tuning element.
There are a large variety of ECL cavity configurations. In some examples, the tuning element is located in the middle of the cavity between the reflectors that define the laser cavity. In other examples, the tuning element is located at one end of the cavity, functioning as both a laser cavity mirror and tuning element.
U.S. Pat. No. 6,345,059, entitled, "Short Cavity Tunable Laser with Mode Position Compensation," and U.S. Pat. No. 6,339,603, entitled, "Tunable Laser with Polarization Anisotropic Amplifier for Fabry-Perot Filter Reflection Isolation" illustrate ECLs using a Fabry-Perot filter tuning element that is located in the middle of the laser cavity.
The location of the Fabry-Perot tuning element in the middle of the cavity can render these ECL designs somewhat complex to manufacture. Isolation is required on either side of the Fabry-Perot tunable filter. This isolation ensures that the laser functions in response to the transmission filter function of the Fabry-Perot tunable filter, rather than its broadband or notch filter function reflection. The transmission of a Fabry-Perot tunable filter spectrally appears as an Airy function with a series of spectrally separated Lorentzian passbands, which are separated by the free spectral range of the filter. Generally, the laser gain chip locks onto one of these passbands to thereby define the wavelength of the ECL. The isolation is important because, in reflection, the Fabry-Perot tunable filter appears as a notch filter, providing very broadband reflection except for the relatively narrow band that is transmitted.
On the other hand, Fabry-Perot tuning elements have some advantages. They can be manufactured using robust micro-electro-mechanical system (MEMS) technologies. Moreover, these ECL cavity configurations can provide relatively broad tuning ranges, only limited by the chip gain bandwidth and the effective bandwidth of the isolation elements.
Isolation for intracavity Fabry-Perot tuning elements, at least those using flat-flat mirrors, can be achieved with simpler configurations. An article by P. Zorabedian, et al. in Optics Letters, Vol. 13, No. 10, October 1988, entitled, "Interference-Filter-Tuned, Alignment-Stabilized, Semiconductor External-Cavity Laser," discloses a semiconductor ECL using an interference or resonant etalon filter. The filter is angled relative to the optical axis of the ECL cavity. As a result, light is reflected at an angle to the laser cavity's optical axis by the interference filter and is therefore not coupled back into the semiconductor gain medium; this angling avoids the need for discrete intracavity isolation elements. In contrast, light that is transmitted through the interference filter, being on resonance, oscillates within the laser cavity and is therefore amplified by the chip gain medium.
A similar system was disclosed in U.S. Pat. No. 4,504,950 to AuYeung. There, a gap was used to form an intra-cavity etalon to create, in combination with a laser diode, an external cavity laser configuration. A micro-electrical and mechanical translator was used to tune this gap and thereby control the wavelength of the output. The gap was angled relative to the laser cavity in order to ensure that the laser diode locked on the resonant feedback transmission from the etalon and not the off-resonance light.
The lasers described in U.S. Pat. No. 4,504,950 and the Zorabedian article use resonant filters that are constructed from two flat mirrors. Such resonant filters support a continuum of plane wave spatial modes. Thus, these filters can be angled tuned as in the Zorabedian article by changing the angle the modal plane wave makes with the optical axis of the resonator. Or, they can be tuned by varying the optical gap, as disclosed in U.S. Pat. No. 4,504,950. In either case, the flat-flat resonator cavities avoid problems stemming from higher order spatial modes from the filters affecting the filter transmission characteristics. The angle isolation strategy, usable with these flat-flat mirror filters, provides a much simpler cavity design and therefore eases the manufacturing challenges over systems as described in U.S. Pat. Nos. 6,345,059 and 6,339,603.
The isolation problems characteristic of these Fabry-Perot based ECLs are not encountered in some other ECL configurations. Another class of ECLs uses grating or holographic tuning elements. Here, the most common ECL configurations are termed Littman-Metcalf and Littrow. In the Littrow design, the emission from a gain element, such as a laser diode or reflective SOA, is directed to a grating. A portion of the light from the grating is reflected to provide narrow band feedback into the SOA through its AR coated facet, whereas another portion of the beam grazes off of the grating to form the output beam. The spatial distribution of the spectrum by the grating presents only narrow band feedback into the semiconductor chip. In the Littman-Metcalf configuration, the output through AR coated facet of a reflective SOA facet is directed to a grating. A portion of the light grazes to form the output beam. Another portion is reflected toward a turning mirror that then retro-reflects the light to the grating and back into the SOA through the AR coated front facet. Tuning in the Littrow configuration is performed by mechanically rotating the grating, which changes its effective pitch. This tuning, however, also changes the position of the output beam. In contrast, in the Littman-Metcalf configuration, the rotating mirror varies the effective grating pitch and tunes the laser. There is little movement in the output beam since the grating is usually not moved, however.
These grating based ECLs are commercially available. Most recently, relatively compact semiconductor laser systems with MEMS grating tuning have been developed and commercialized.
A further class of ECLs is based on coupled cavity configurations. One example is shown in WIPO Publication No. WO 95/13638, in which a resonant filter is formed between a back facet of a laser chip and a MEMS, electrostatically-driven reflecting element. By changing the size of this rear cavity, it is suggested that the output of the laser is tuned. A similar system is disclosed in a paper entitled, "Coupled-Cavity Laser Diode with Micromachined External Mirror," by Yuji Uenishi from NTT Interdisciplinary Research Laboratories in Tokyo, Japan, in IEEE/LEOS 1996 Summer Topical Meetings: Optical MEMS and Their Applications, Keystone CO, pp. 33-34, 1996.

Laser with tilted multi spatial mode resonator tuning element


A drive socket for a male threaded fastener includes a plurality of rounded lobes of equal radius which are located equidistant from the center of the fastener and an equal distance from each other. The drive socket also includes flat surfaces located opposite the lobes and equidistant from the center of the fastener. Another embodiment of a drive socket includes a first set of lobes and a second set of lobes, each lobe being of equal radius and equidistant from the center of the fastener. The lobes of the first set are equidistant apart and the lobes of the second set are also equidistant apart and equidistant apart from the adjacent lobes of the first set on either side of the lobe of the second set. Each of the lobes of the first set includes a flat surface which is adjacent and tangential to the radius portion of the lobe.

1. Field of the Invention
This invention relates generally to structural fasteners, and more particularly relates to drive sockets on threaded male structural fasteners.
2. Description of the Related Art
Threaded male structural fasteners of the type to which this invention is directed include an axial drive socket, or wrench engaging recess, located either on a head (FIG. 1a) of the fastener or on the opposite end of the fastener (FIG. 1b). The drive socket (FIG. 1c) includes a plurality of substantially equally spaced and sized flat surfaces which receive a mating wrench type key, or wrench key. The drive socket may be hexagonally shaped to receive a hexagonal Allen wrench type key, or hex-key driver. During use, an end of the wrench key is inserted into the drive socket in the male fastener and is either held in place to permit a threaded female fastener, such as a nut, to be screwed onto the threads of the male fastener, or the hex-key driver is rotated in order to screw the male fastener into the female fastener or other female threaded hole.
Clearance is required between a hex-key driver and the drive socket which the hex-key driver is inserted into. For example, the clearance between a 2.4 mm ( 3/32-inch) hexagonal drive socket and a 2.4 mm ( 3/32-inch) hex-key driver is 0.04 mm (0.0015 inch) all around. With this amount of clearance, the hex-key driver can rotate approximately three degrees before contacting the mating surfaces of the drive socket (FIG. 1d), resulting in the intersections, or corners, between the surfaces of the hex-key driver contacting the flat surfaces of the drive socket. With the corners between the surfaces of the hex-key driver providing the main driving force from the hex-key driver, high stress concentrations are placed on the corners of the hex-key driver, but there is very little material providing support for the corners. As a result, when a load that is sufficient to set the desired torque between the male threaded fastener and the female threaded fastener or part is applied to a hex-key driver during use, the material at the corners may shear off of the hex-key driver, leaving the hex-key driver in a stripped condition.
Another problem that can occur is that as the hex-key driver is rotated within the drive socket, the hex-key driver may become wedged within the socket, thus causing the hex-key driver to bind within the socket. After setting the desired torque between the male threaded fastener and the female threaded fastener, rotation of the hex-key driver must be reversed to break the bind between the hex-key driver and the socket.
Methods which have been developed to prevent the stripping of hex-key drivers during use include fabricating the hex-key drivers from stronger materials. Yet, making the hex-key driver stronger may lead to stripping the drive socket during high stress applications. Another method of preventing hex-key drivers from stripping includes making the drive sockets in the fasteners deeper. However, making the drive socket deeper may compromise tensile strength of the fastener through the area of the drive socket, especially on fasteners having the drive socket on the end of the fastener opposite the head (FIG. 1b).
One attempt to alleviate the problem of the hex-key drivers stripping within the drive sockets included reconfiguring the drive socket to include six rounded lobes of substantially equal radius, as depicted in FIG. 2a. The lobes are located substantially equidistant from the center of the fastener. Also, adjacent lobes are located substantially equidistant circumferentially from each other. Each of the lobes projects inward toward the center of the fastener. The embodiment also includes curved recesses located between and adjacent each lobe, thereby combining for a total of six recesses. Each of the recesses is blended into its adjacent lobes to form a substantially smooth transition between the lobes and the recesses.
Referring to FIG. 2b, when the hex-key driver is rotated, such as to drive the male threaded fastener relative to a female threaded fastener, a portion of the flats on the hex-key driver contact the lobes while the corners of the hex-key driver remain within the recesses and out of contact with the wall of the drive socket. One problem with the configuration of FIGS. 2a and 2b is that it enlarges the drive socket considerably, thereby weakening the fastener head.
Hence, those skilled in the art have recognized a need for a male threaded fastener having a drive socket that may receive high stress from a hex-key driver and reduce the tendency of the hex-key driver to strip or to bind within the drive socket. The need to configure the drive socket so that it substantially maintains the tensile strength of male threaded fasteners and the strength of the fastener heads has also been recognized. The present invention fulfills these needs and others.