A sample preparation process and apparatus are provided for samples to be analyzed subsequently, such as by liquid chromatography. The sample is passed in contact with an ion exchange polymer which is characterized by being capable of facilitating removal of one or more undesired ions from the sample to be replaced with an ion transferred from the bound exchange site of the polymer and through the polymer. The polymer is prewashed with water to remove substantially all leachable species from the polymer. In one embodiment, the polymer is coated with a color indicator capable of changing color when the polymer is depleted of the ion to be transferred therefrom. The ion exchange capacity of the apparatus can be significantly expanded by using a counter ion donating solution capable of replacing the bound ions at the ion exchange sites as they become exchanged for the undesired ions from the sample.

This invention relates to a process and apparatus for preparing samples to be analyzed for ionic species such as by liquid column chromatography.
At the present time, it is known that several typical liquid samples containing ionic species cause serious problems when analyzed by ion chromatography apparatus. Included in these samples are those having a pH value greater than pH 10 or lower than pH 4, samples with high carbonate concentration and samples containing high concentrations of divalent cations such as calcium and/or magnesium. Presently these samples are prepared for subsequent analysis by adding thereto acidic or basic solutions in order to permit identification of the ionic species for which the analysis is being made without interference by other ionic species in solution. These sample preparation processes are undesirable since they introduce significant interference from the counter ions from the added acid (anions) or base (cations). This can cause considerable interference which can limit the capability of the analysis apparatus to properly determine the individual constituents and their amounts in the sample.
Attempts to utilize ion exchange resin beads to remove undesired ions is an improvement in that it eliminates the addition of excessive counter ions as these counter ions are covalently bound to the bead. In this process, the sample volume selected for analysis is passed through, on or over the polymeric like structure which includes counter ions bonded to either a silicate or an organic polymer bead. The potentially interfering counter ions are sufficiently bonded to the beads as to preclude direct analytical interference. However, the beads are themselves a source of organic and inorganic contamination. Even a repeated and very extensive precleaning of the ion exchange resin beads does not prevent sample contamination at the levels detachable by presently available ion chromatography apparatus. In addition, the resin beads have adsorption-desorption capacity so that a portion of the ions being analyzed are adsorbed into the pores of the resin beads. The net effect is the possibility of skewing and/or loss of the resultant data during the analytical process thereby negating any anticipated advantage by selecting these materials as a means for improving the chromatographic analytical process.
It has also been known prior to this invention to utilize hollow fibers having an ion exchange capacity to purify a continuous stream of a gas passing therethrough.
A hollow fiber is defined as a seamless thin walled member of essentially tubular geometry with an inlet and outlet means where the constituent to be purified or reacted upon is communicated into the center of the tubular membrane system through the inlet, subsequently acted upon in a chemical manner by the tubular portion itself and/or by other reacting mechanism(s) present during the time the constituent is residing in the tubular portion of the fiber and subsequently removed through or passed from the tubular geometry by or through the outlet means. Such hollow fiber systems may be of singular or multiple path geometries and may also be immersed in solutions and/or gasses or connected with systems designed to promote the exchange process. An example is the use of sulfuric acid surrounding a hollow fiber to promote the exchange of protons across the hollow fiber tubular member portion. Such an added solution to a hollow fiber system component in this way is defined as a counter ion donating solution or CIDS. However, it is also known that the solution comprising the source of regenerated ions can penetrate the hollow fibers such that the proton donator, e.g., sulfuric acid, contaminates the liquid by passing sulfate ions through the hollow fiber.
Accordingly, it would be desirable to provide a method for effecting sample preparation for ion analysis without the need for adding an acidic or basic solution to the sample since such prior art methods introduce significant interferences into the sample. In addition, it would be desirable to provide such a method wherein impurities from the ion exchange medium into the sample are eliminated. Furthermore, it would be desirable to provide such a sample preparation means which can be used with a wide variety of liquid samples. In addition, it would be desirable to provide a sample preparation means which can rapidly process a large number of samples before being replaced. Also, it would be desirable to provide a sample preparation means which provides a simple means by which the operator can replace depleted ion exchange polymer.

Process for analyzing samples for ion analysis


An inverter circuit having a primary circuit with a first choke for periodically connecting a primary winding to a DC voltage present at an input of the inverter circuit, a secondary circuit with a secondary winding, the secondary winding arranged in series with a first capacitor and connected via a full bridge consisting of four switching elements to a AC voltage present at an output of the inverter circuit via a second choke, and a transformer, wherein the primary circuit and the secondary circuit are electrically isolated by the transformer.

A large number of inverter circuits with different possible applications are known from the prior art. These use various basic types of electronic converters such as boost converters, buck converters or buck-boost converters and combinations thereof. Examples may be found in a publication in the periodical EDN of 17 Oct. 2002 "Slave converters power auxiliary outputs", Sanjaya Maniktala, which describes various possible combinations of basic inverter types.
Different inverter circuits and their electronic control circuitry are also known e.g. from C. M. Penalver et al. "Microprocessor Control of DC/AC Static Converters"; IEEE Transactions on Industrial Electronics, Vol. IE-32, No. 3, August 1985, pp. 186-191.
Inverter circuits are used, for example, in photovoltaic systems to convert the direct current generated by photovoltaic cells so that it can be fed into public utility grids. Particularly in photovoltaic systems, high efficiency inverter circuits are required in order to enable this alternative source of power to be used cost-effectively. In addition, various conditions imposed by the power utilities and authorities must be met, e.g. the injection of a sinusoidal current or electrical isolation between photovoltaic cells and utility grid.
The publication: Heinz van der Broeck, "Interactive Inverter for Photovoltaic Applications", Institute for Automation Technology, Cologne University, Cologne (2006) gives details of various inverter circuits for use in photovoltaic systems. The disadvantage with these topologies, however, is the number of components required, particularly of electronic switches, because this means increased switching losses and component costs.

Inverter circuit and method for operating the inverter circuit


In at least one embodiment, the present invention relates to a modular vehicle interior component system which comprises a base having a channel defined at least in part by a latching lip, a vehicle interior component, and a release latch mechanism for slidably and releasably securing the component to the base.

1. Field of the Invention
The present invention relates to modular vehicle interior component systems and release latch mechanisms for use with such systems.
2. Background Art
Vehicles today are increasing designed to carry a wide variety of cargo. In addition to carrying large items which may be stored in a rearward portion of the vehicle, passenger compartments are also configured to carry, and provide access to, a wide variety of accessories and components, including entertainment devices and area-specific environmental controls. In addition, vehicle consoles often provide empty space that can be used to store a variety of different items.
One limitation of many of these designs is that the vehicle console is a static structure—i.e., the vehicle occupant must accept the configuration of the console, and cannot tailor it to his or her specific needs. Attempts to address this issue include the development of reconfigurable consoles for vehicles.
There exists a need for a modular vehicle interior component system where in the components can be selectively positioned as desired by the vehicle occupant at any location along the base.

Modular vehicle interior component system and release latch mechanism for use with the system

International Automotive Components Group North America, Inc.


A washing machine appliance includes a sump for collecting wash fluid, a water supply valve for supplying the wash fluid during a fill cycle, and a water level detection system including a pressure sensor for measuring sump pressures/fill levels. A controller is configured for operating the supply valve to fill the sump until a target volume is reached and obtaining a fill volume using the water level detection system. The controller determines that a fault condition exists based on a difference between the target volume and the fill volume, e.g., such as when the difference exceeds a predetermined fault threshold, and initiates a fault abatement process in response to determining that the fault condition exists.

Washing machine appliances generally include a tub for containing water or wash fluid, e.g., water and detergent, bleach, and/or other wash additives. A basket is rotatably mounted within the tub and defines a wash chamber for receipt of articles for washing. During normal operation of such washing machine appliances, the wash fluid is directed into the tub and onto articles within the wash chamber of the basket. The basket or an agitation element can rotate at various speeds to agitate articles within the wash chamber, to wring wash fluid from articles within the wash chamber, etc. During a spin or drain cycle, a drain pump assembly may operate to discharge water from within sump.
Conventional washing machine appliances may include water level detection systems for detecting the amount of water dispensed into the tub during a fill cycle or the amount of water remaining within the sump after a drain cycle. For example, water level detection systems may include pressure sensors coupled to pressure hoses on the sump for detecting the water pressure for determining the water level. Such systems can use this information to detect fill or drainage issues, such as a drain pump failure, and to ensure the ideal amount of water is in the tub for performing a particular wash cycle. However, in certain situations, the pressure sensor may become partially blocked or may otherwise malfunction, resulting in erroneous pressure readings and/or a delayed response. Failure to compensate for such variations in pressure readings can result in overfilling or underfilling the tub.
Accordingly, a washing machine appliance having improved water level detection systems would be desirable. More specifically, a water level detection system with fault detection would be particularly beneficial.

Fault detection for a water level detection system of a washing machine appliance


Solid catalyst components for the preparation of catalysts capable of producing polymers and copolymers of ethylene with ultra high molecular weight are obtained in the form of particles having an average diameter of less than 10 micrometers, by way of reaction, in the presence of H.sub.2 O, between:. 1) a liquid obtained by reacting: PA1 A) a titanium compound containing at least one Ti--OR bond, where R is a C.sub.1 -C.sub.20 alkyl, C.sub.3 -C.sub.20 cycloalkyl, or C.sub.6 -C.sub.20 aryl radical; with PA1 B) a magnesium compound selected from the group consisting of: halides; compounds comprising at least one --OR or--OCOR group bonded to the magnesium, where R is a C.sub.1 -C.sub.20 alkyl, C.sub.3 -C.sub.20 cycloalkyl, or C.sub.6 -C.sub.20 aryl radical; organometallic compounds; products of the reaction between the above mentioned compounds and electron-donor compounds; and PA1 2) a compound or composition capable of halogenating and optionally reducing (A).

In the art it is already known, particularly from U.S. Pat. Nos. 4,218,339 and 4,296,223, how to prepare solid catalyst components by way of reaction, in various combinations, between:
A) a titanium alcoholate or a titanium halogen alcoholate (i.e., haloalcoholate); PA1 B) a magnesium halide, or a magnesium organic or organometallic compound, or their reaction products with an electron-donor compound; PA1 C) a compound or composition capable of halogenating and optionally reducing compound (A). PA1 A) the reaction product of a magnesium dihalide and a titanium tetraalcoholate. PA1 B) the reaction product of an aluminum trihalide and a silicon tetraalcoholate. PA1 1) a liquid obtained by reacting: PA1 2) compound or composition capable of substituting in compound (A) at least one --OR group with a halogen atom, and optionally reducing the titanium of compound (A) to an oxidation state lower than 4, PA1 ethylene pressure=5-20 atm; PA1 temperature=50.degree.-85.degree. C.; PA1 polymerization time=1-5 hours.
When said catalyst components are activated with an aluminum alkyl compound, they produce catalysts which are active in the (co)polymerization of .alpha.-olefins, and in particular of ethylene.
Moreover, with said catalyst components, and particularly with those described in U.S. Pat. No. 4,218,339, one can obtain homopolymers of ethylene with a narrow molecular weight distribution.
In the case of copolymers of ethylene with .alpha.-olefins, the catalyst components of the above mentioned types allow one to obtain physico-mechanical properties which are very high when compared to the low comonomer content, as described in published European patent application 7647.
Said results can be attributed to a particularly good distribution of the comonomer in the polymer chains.
One of the preferred techniques for the preparation of said catalyst components consists in causing them to precipitate from a liquid phase (either using the reagents as such, when possible, or in solution), under particular mixing conditions, in order to obtain particles with a morphology as regular as possible, and a controlled particle size distribution.
The catalysts deriving from catalyst components obtained in such a manner, due to the well known phenomenon of morphologic replica on the part of the polymer (wherein the morphology of the polymer particle substantially replicates that of the catalyst particle), allow one to obtain polymers in the form of particles with a regular and controlled morphology and high flowability.
Said polymers, therefore, have a high processability during polymerization and recovery from the polymerization reactors, and can easily be fed to the processing apparatus.
However, as indicated in published European patent application 7647, by operating with the above mentioned technique of precipitation from a liquid phase, one cannot generally obtain catalyst component particles with a diameter smaller than 10 micrometers.
When used in the (co)polymerization of ethylene, said particles produce polymers in the form of particles having a diameter from 100 to 500 micrometers, and, therefore, an average diameter well over 100 micrometers, and usually from 200 to 400 miorometers.
It is also known that in the case of .alpha.-olefin polymers, particularly ethylene, having very high molecular weight (i.e., having an intrinsic viscosity [.eta.] in tetralin at 135.degree. C. higher than or equal to 10, and generally from 10 to 30 dl/g), it is particularly advantageous to have especially fine polymer powders with good compactness and flowability.
In fact, given the high viscosity that said high molecular weight polymers maintain in the molten state even at high temperatures, the standard molding processes which use melted polymer are inadequate for the manufacture of articles.
A valid solution in this case is compression molding, by which one obtains, by cohesion and compaction of the polymer powders at high temperatures, a finished product whose physico-mechanical properties generally improve the finer the particles of the initial polymer powders are, said particles having a regular form and a controlled particle size distribution. For good processability and finished product quality, it is also helpful if the polymer particles are adequately porous.
The finished products obtained from high molecular weight polyethylene are particularly suitable for a number of uses where high mechanical properties are needed (for example in the manufacture of gear parts or components for arthroprostheses)
Published European patent application 317200 describes a process for the preparation of polyethylene with ultra high molecular weight in the presence of a catalyst comprising a solid catalyst component obtained from the reaction between:
However, in spite of the fact that one of the objectives of the above process is to obtain a polymer in the form of very fine particles, the average diameter of said particles, in the examples, does not go below 195 micrometers.
Therefore, it would be an advantage if there were catalyst components of the above mentioned type in the form of very fine particles, with a regular morphology and controlled particle size distribution, capable of producing, by replica, polymer powders with good form, density and flowability characteristics, especially suitable to be used in processes for the manufacture of sheets (compression molding) or rods (ram extrusion).
This objective cannot be best reached by grinding the solid catalyst component or polymer powders, since grinding produces powders with too many different dimensions, an irregular form, and a particle size distribution which cannot be controlled. Moreover, grinding also causes a decreased consistency and porosity of the polymer particles.
Said morphologic irregularities cause poor flowability of the polymer powders, and usually a deterioration of the physico-mechanical properties of the products obtained by compression molding.

Components and catalysts for the polymerization of ethylene


A dual-rate drive coupling (20) for use in transmitting drive torque between drive and driven members. The first torque rate is near zero for no-load and near no-load conditions. A pair of flexible elastomeric arms (24, 26) which is preferably bonded to the inner member (22) are received in recessed portions (44, 46) in the outer member (40) and provide the coupling with this first very low torque rate. When higher torque loading produces a relative rotation between the outer member (40) and the inner member (22) of at least about 15.degree., a pair of snubbing arms (28, 30) of the inner member (22) interact with surfaces of openings (48, 50) of the outer member (50). The contact surfaces of these second snubbing arms (28, 30) are coated with an elastomer to snub all contact between the inner member (22) and the outer member (40) to inhibit vibration induced rattling. In a second preferred embodiment, the elastomeric arms are curved in opposite directions and the metal arms are skewed away from drive engagement such that a relative rotation of at least about 25.degree. is needed to bring the second pair of arms (28, 30) into driving engagement with the outer member (40).

This invention is directed to a dual-rate coupling and bonded component therefor for transmitting drive torque to between drive and driven members. More particularly, the present invention is directed to a dual-rate coupling which has near zero stiffness at low torque loadings.
Drive couplings are known which transmit torque through an elastomer member, such as described in U.S. Pat. Nos. 4,772,245, 4,634,391, 4,516,956, 2,195,993, and 1,941,061. Single stage couplings have the problem in that at no-load or near no-load torques, a rattle may be produced between the drive and driven components that manifests itself as noise in the drive assembly. In addition to the obvious auditory irritation, the rattle produces accelerated wear on the chattering parts. To solve this, a low torsional stiffness is desired. However, the concomitant result of low torsional stiffness is large torsional windup. To solve this dilemma, dual-rate couplings have been developed which limit torsional deflections yet, at the same, time provide low initial stiffnesses. Such multi-rate couplings are described in U.S. Pat. Nos. 5,573,562, 5,522,747, 3,727,431, 3,438,222, 3,386,264, and 2,822,676. Notably, known dual-rate couplings may still provide an initial stiffness that is too great for some applications.
The dual-rate drive coupling of the present invention solves this rattle problem by providing very low, near zero stiffness at no-load or near no-load torques, yet provides a high stiffness for transmitting torques, when needed at higher torques.
Accordingly, the dual-rate drive coupling of the present invention comprises an inner member including a pair of snubbing arms; a pair of elastomeric arms extending outwardly from the inner member, each of the elastomeric arms having a length, a width and a thickness, where the length is greater than the thickness; and an outer member including a first pair of openings which receive the pair of elastomeric arms and a second pair of openings receiving the pair of snubbing arms, the pair of elastomeric arms interconnecting to said outer member at outer portions thereof whereby the pair of elastomeric arms exhibit near zero torsional stiffness and the pair of snubbing arms drivingly interconnect with the second pair of openings as torque increases above said minimum threshold torque level.
In another aspect, the pair of snubbing arms are coated on all surface portions engaging the second pair of openings with elastomer to prevent metal-to-metal contact. Preferably, the metallic portion of each of pair of snubbing arms tapers toward an outer end and a coating of elastomer is shaped to render the second pair of arms generally rectangular. In another aspect, the elastomer arms have at their terminus an enlarged portion which is received in similarly configured recesses formed in the outer member. Preferably, these enlarged portions are compressed within the similarly configured portions. To further prevent rotation, the enlarged protrusion preferably has an hyperextended portion which engages in a notch in a similarly configured portion of said outer member to provide an orientation feature. In another aspect of the invention, each of the pair of elastomer arms is compressed along their length in order to further reduce torsional stiffness. In yet another aspect, the elastomer arms have a slight curvature which skews the pair of radially extending snubbing arms within the second pair of openings, in a zero load condition, away from contact between a pair of drive surfaces on said pair of snubbing arms and said second pair of openings and a driven surface on said second pair of openings. This skewing of said pair of radially extending snubbing arms may be, at least in part, due to a characteristic premolded into said pair of elastomer arms.
Various other features, advantages and characteristics of the present invention will become apparent after a reading of the following detailed description of the preferred embodiments of the present invention.

Dual-rate coupling exhibiting an ultra-soft initial spring rate and bonded component therefor


A navigation apparatus including a central processing unit, an imaging module, a GPS module, a tire pressure monitoring module, and a storage module is provided. The imaging module captures an image signal. The central processing unit controls the imaging module to capture the image signal for generating image data, and further stores the image data in the storage module. The central processing unit executes the electronic map software stored in the storage module and receives the positional data generated by the GPS module for generating route guidance. The central unit receives the digital tire pressure signal received by the tire pressure monitoring module to generate tire pressure data and further identifies whether or not the tire pressure data is in compliance with a safety value.

1. Field of the Invention
The present invention relates to a navigation apparatus, and more particularly to a navigation apparatus that concurrently records image data and tire pressure data, and a method for monitoring vehicle safety via the navigation apparatus.
2. Description of Related Art
The Global Positioning System (GPS) is a system that receives satellite signals and analyzes satellite orbiting data to find the location of a satellite, and then computes the positional data including longitude and latitude coordinates, direction, and speed of a receiver via a trigonometric positioning algorithm. Since GPS is a high-precision positioning system which is unaffected by location and time, the GPS service and its related products are widely used. In a variety of different new products, GPS is used as navigation apparatus for obtaining positioning information and providing route guidance.
Referring to FIG. 1 a schematic view of the system architecture of a conventional navigation apparatus 10 is shown. The navigation apparatus 10 includes a GPS module 11, a central processing unit 13, a memory unit 15, and a display interface 17. The GPS module 11 includes an antenna 111 and a signal processing unit 113. The antenna 111 receives a satellite signal and transmits the satellite signal to a signal processing unit 113 for amplifying, filtering and digitizing the signal, and then transmits the digital satellite signal to the central processing unit 13. The memory unit 15 is provided for storing software, receiving data, and processing programs, navigated formula computation programs and electronic maps, wherein the electronic map is a vector map composed of longitude and latitude coordinates. The central processing unit 13 executes the aforementioned software to compute and analyze the satellite signals, unload the electronic map from the memory unit 15, superimpose the received positional data on the map, output the result through the display interface 17, and provide route guidance for the user.
At present, automobile navigation apparatuses are divided into two main models: a model that embeds a GPS module and an electronic map into a motor vehicle and integrates them with a computer and a display device of the motor vehicle, and a second model that affixes a portable navigation apparatus near the driver's seat. Since the price of a motor vehicle increases if the navigation apparatus is built into the motor vehicle and older models of motor vehicles seldom come with navigation functions, the most common method is the second model of affixing a portable navigation apparatus in a motor vehicle to serve as an automobile navigation apparatus.
As we all know, car accidents generally cause tremendous damage the vehicles and injury or death to those involved. Some drivers install a camera at the front side of the motor vehicle to take pictures as the motor vehicle is driving that records images of an accident for evidence. Furthermore, the number of motor vehicles is continuously increasing, and thus driving safety is becoming a more important issue. Since the tire pressure monitoring system (TPMS) that is based upon micro electro-mechanical system (MEMS) technology was introduced, the tire pressure and temperature of a motor vehicle can be monitored. When, as an example, a tire leaks or the pressure of the tire becomes low, an alarm signal will be issued to warn the driver about the condition of the tire, so as to help prevent accidents. Since tire pressure is indispensably related to driving safety the tire pressure monitoring system has gradually become a necessary piece of equipment for all motor vehicles.
Since communication and network technologies are currently developing rapidly, navigation apparatuses further have begun to include communication and network functions to provide diversified services to users. The navigation apparatuses of this sort not only satisfy a user's entertainment requirements, but also bear a hidden risk in that they can distract a driver and lead to car accidents. There is no portable navigation apparatus currently available in the market that integrates the aforementioned image recording and tire pressure monitoring functions. In view of this situation, the inventor of the present invention intends to integrate image recording and tire pressure monitoring functions into a navigation apparatus, so as to enhance the navigation apparatus and improve driving safety.

Navigation apparatus and method for monitoring vehicle safety


An inventive method tracks IC devices through the assembly steps in a manufacturing process. Prior to die attach, a laser scribe marks the lead frame of each of the devices with a coded hole matrix that gives each device a unique ID code. During die attach, an optical hole reader retrieves the ID code of each of the IC devices, and a computer system stores the retrieved ID codes in association with the lot numbers of the ICs attached to the lead frames. The ID codes of the devices are then read at each step in assembly so the devices can be tracked through assembly individually, rather than by lots. As a result, the devices can proceed through assembly in a more efficient, continuous manner (i.e., without breaks between lots).

1. Field of the Invention
This invention relates in general to methods for manufacturing integrated circuit (IC) devices. More specifically, the invention relates to non-lot based IC device manufacturing methods in which individual devices can be uniquely identified during their assembly, which enables individual tracking of the devices through assembly and, in turn, enables assembly of the devices in a substantially continuous manner.
2. State of the Art
As shown in FIG. 1, a process 10 for manufacturing integrated circuit (IC) devices typically begins with ICs being fabricated on the surfaces of wafers 12 of semiconductor material, such as silicon. Less typically, ICs may also be formed in layers of silicon deposited on layers of sapphire known as Silicon-on-Sapphire (SOS), Silicon-on-Insulator (SOI), or Silicon-on-Glass (SOG).
Once fabricated, ICs are electronically probed to determine whether they are functional (i.e., "good") or nonfunctional (i.e., "bad"). A computer then stores electronic wafer maps 14 of the wafers 12 identifying the locations of the good and bad ICs on the wafers 12.
After being probed, ICs are sawed from their wafers 12 into discrete IC dice (also known as "chips") using high-speed precision dicing equipment. IC dice identified as good by their wafer maps 14 are then each "picked" by automated equipment from their sawed wafers 12 and "placed" on an epoxy coated bonding site of one of a set of lead frames 16, while IC dice identified as bad are discarded into a scrap bin 18. The epoxy attaching the good IC dice to their lead frames 16 is allowed to cure, and the attached dice are then wire bonded to their lead frames 16 using high speed bonding equipment. At this point in the process 10, the lead frames 16 of IC dice are still interconnected.
Once wire bonded, IC dice and their lead frames 16 are formed into IC packages using a hot thermosetting plastic encapsulant injected into a mold. Leads of the lead frames 16 project from the IC packages after encapsulation, and these leads are dipped in a cleansing chemical bath in a process referred to as "de-flash." After de-flash, IC packages are cured to set their plastic encapsulant, and their projecting leads are then electroplated with a lead/tin finish.
After lead finishing, connections between the lead frames 16 of different IC packages are cut to "singulate" the IC packages into discrete IC devices, and the leads projecting from each IC device are then trimmed and formed into their final form. The IC devices are then tested in a simple electronic test that checks for "opens" (i.e., no connection) in the devices where connections should exist and "shorts" (i.e., a connection) where connections should not exist. Devices that fail the opens/shorts test are discarded into the scrap bin 18, and devices that pass proceed to extensive back-end test procedures where they are tested for functionality before being shipped to customers.
ICs are typically tracked by lot number through the fabrication, probe, assembly, and back-end test steps described above so the location of particular lots of ICs within the manufacturing process 10 can be determined. Lot numbers are first assigned to ICs when they are fabricated on semiconductor wafers 12. Typically, a group of 20–50 wafers 12 receives a unique lot number (e.g., 36/1/9970). As the group of wafers 12 proceeds to probe, the wafers 12 are typically split into several sub-lots, with each sub-lot being assigned a new lot number (sometimes referred to as a "sub-lot" number) that is a modified form of the group's original lot number (e.g., 36/1/9970/0, 36/1/9970/1, . . . ). As the group continues through the manufacturing process 10, sub-lots are split and re-split for a variety of reasons until the group is typically split into many sub-lots, all having a unique lot number that is a modified form of the group's original lot number.
An example of ICs being tracked through a portion of assembly using lot numbers is shown in FIG. 2. In the example, ICs are first processed on molding equipment to encapsulate them. Once encapsulated, ICs are fed into output carriers 20, each of which has a unique carrier number (e.g., a bar code). The lot numbers of ICs fed into a particular output carrier 20 are stored in association with the carrier number of the carrier 20 in a data store 22, such as a computer memory system. The output carriers 20 containing the encapsulated ICs are then placed on shelves, with the carrier number of each output carrier 20 being stored in the data store 22 in association with a unique shelf number of the shelf on which the output carrier 20 is placed (e.g., by scanning in the bar code of each output carrier 20 and a bar code of the shelf on which it is placed). Later, selected ICs are retrieved by lot from the shelves for processing on de-flash equipment by first identifying the output carriers 20 associated in the data store 22 with the lot number of the selected ICs, then identifying the shelves associated in the data store 22 with the carrier numbers of the identified output carriers 20, and finally retrieving the identified output carriers 20 from the identified shelves for processing.
Unfortunately, the conventional lot-based tracking procedure described above is not as efficient as desired, as is illustrated by FIG. 3. In a typical assembly step 24, a sub-lot (e.g., sub-lot H) is received from an input queue 26 where sub-lots wait to proceed through the assembly step 24. The assembly step 24 may be any step in the IC assembly process of FIG. 1, including, for example, wafer saw, die attach, die cure, wire bond, molding, de-flash, lead finish, trim and form, and opens/shorts testing.
As a sub-lot advances through the assembly step 24, data 28 related to the assembly step 24 is generated. Such data 28 may include, for example: an identification of the processing equipment and the operating personnel for the assembly step 24; information regarding the set-up of the assembly step 24; and the time and date the sub-lot advanced through the assembly step 24.
Once a sub-lot has advanced through the assembly step 24, a process report 30 is manually or automatically generated based on the generated data 28. To associate the process report 30, and hence the data 28, with the ICs in the sub-lot, and thus track the ICs through the assembly step 24, the process report 30 lists the lot number (e.g., "H") of the ICs in the sub-lot. Typically, the process report 30 (often referred to as a "lot traveler") also physically accompanies the sub-lot through the remainder of the manufacturing process to ensure that the data 28 is correlated with the ICs in the sub-lot.
With the process report 30 generated, a processed sub-lot (e.g., sub-lot H) is cleared from equipment associated with the assembly step 24 to an output queue 32 to prepare the assembly step 24 for processing the next sub-lot (e.g., sub-lot I). Once the processed sub-lot is cleared, the next sub-lot can be processed. This "clearing" process is necessary because if two sub-lots (e.g., sub-lots H and I) proceed through the assembly step 24 in a continuous manner, the conventional lot-based tracking procedure described above is unable to correlate the data 28 and the process report 30 generated as each of the two sub-lots proceeds with the correct sub-lot. Instead, the data 28 for the two sub-lots is mixed, causing the conventional tracking procedure to fail to uniquely track the two sub-lots through the assembly step 24.
Thus, the described conventional lot-based tracking procedure is inefficient because it makes inefficient use of often very expensive manufacturing equipment and other resources by leaving sub-lots "parked" in input queues while process reports are generated and the equipment is cleared of already processed sub-lots. In assembly steps which use multiple machines in parallel to process a sub-lot (e.g., wire bond), some machines may be idle while other machines finish their allotment from the sub-lot being processed and the next sub-lot waits in an input queue. In addition, generation of the process reports, as well as clearing a processed sub-lot from equipment, often requires laborious manual work by operating personnel. Also, the conventional tracking procedure is not as reliable as desired, because the process reports that must physically accompany sub-lots through the manufacturing process can be lost or damaged.
As described in U.S. Pat. Nos. 5,301,143, 5,294,812, and 5,103,166, some non-lot based methods have been devised to aid quality control personnel in tracking ICs undergoing failure analysis back to the wafer from which they come. By tracking the ICs back to their wafer, test data related to the ICs can be correlated to the wafer to pinpoint possible problems with the wafer. Such methods take place off the manufacturing line, and involve the use of electrically retrievable identification (ID) codes, such as so-called "fuse ID's," programmed into individual ICs to identify the ICs. Fuse ID's and other electrically retrievable ID codes are typically programmed into ICs by blowing selected fuses or anti-fuses in circuitry on the ICs so that the circuitry outputs the ID code when accessed. Unfortunately, none of these methods addresses the inefficiency and reliability problems associated with the conventional lot-based tracking procedure described above.
Therefore, there is a need in the art for a non-lot based procedure for tracking ICs through an IC assembly process that uses manufacturing resources more efficiently. Such a procedure should not leave equipment idle while ICs wait to be processed. In addition, such a procedure should achieve a level of reliability not reached by conventional tracking procedures.

This patent is subject to a terminal disclaimer.

Non-lot based method for assembling integrated circuit devices


Disclosed herein are a device for electrostatic protection and circuit thereof. According to the present invention, a device for electrostatic discharge protection comprises first to third wells formed on a semiconductor substrate, a first device, which includes a well pick-up region, a source region and a double diffused drain region, which are formed in predetermined regions on the first well, and a gate formed in a predetermined region on the semiconductor substrate, a second device, which includes a source region, a double diffused drain region and a first active region, which are formed in predetermined regions on the second well, and a gate formed in a predetermined region on the semiconductor substrate, and a second active region formed on the third well, wherein the gate, the source region and the well pick-up region of the first device are connected to a ground pad; the drain of the first device, and the source and the gate of the second device are connected to a power source pad; and the drain and the first active region of the second device, and the second active region are connecter to an I/O pad. Therefore, a single ESD protection device can cope with ESD stress of six modes, which can occur in each of I/O cells. Accordingly, a layout area necessary for ESD protection can be reduced.

1. Field of the Invention
The present invention relates to a device for electrostatic discharge (hereinafter, referred to as "ESD") protection and circuit thereof, and more specifically, to a device for ESD protection and circuit thereof in which one ESD device can cope with the whole ESD stress of various modes, which can occur in respective I/O cells (or input cells and output cells), thereby reducing a layout area.
2. Discussion of Related Art
A conventional method of constructing an ESD protection circuit in which an ESD protection device is used in each of I/O cells (or input cell, output cell) is shown in FIGS. 1a and 1b.
FIG. 1a shows the configuration of a common ESD protection circuit for I/O cells (or input cells and output cells). FIG. 1b shows the configuration of a plurality of I/O cells, input cells and output cells.
An electrode constituting the respective I/O cells (or input cells and output cell) is composed of a power source pad 11, a ground pad 12, and an I/O pad 13. Furthermore, an input pad 14, which is composed of a first PMOS transistor P11 and a first NMOS transistor N11, is connected between the power source pad 11 and the ground pad 12. The gate of each of the first PMOS transistor P11 and the first NMOS transistor N11 is connected to the I/O pad 13. Also, an output pad 15, which is composed of a second PMOS transistor P12 and a second NMOS transistor N12, is connected between the power source pad 11 and the ground pad 12. The drain of each of the second PMOS transistor P12 and the second NMOS transistor N12 is connected to the I/O pad 13. In this configuration, ESD stress current can flow randomly between two electrodes of three electrodes. Therefore, the ESD stress type, which can occur in all electrode combinations of individual I/O cells, can be classified into the following six modes.
(1) Ground pad positive, power source pad floating, I/O pad ground
(2) Ground pad: ground, power source pad: floating, I/O pad positive
(3) Ground pad: floating, power source pad ground, I/O pad positive
(4) Ground pad: floating, power source pad: positive, I/O pad ground
(5) Ground pad: positive, power source pad: ground, I/O pad floating
(6) Ground pad: ground, power source pad: positive, I/O pad floating
In addition, there is pin-to-pin mode ESD stress in which ESD stress is added between the I/O cells and the I/O cell. Accordingly, an ideal ESD protection circuit can protect against all the six ESD stress modes and the pin-to-pin mode ESD stress. The most common ESD protection circuit has the configuration in which three individual ESD protection devices are disposed for each of electrode combinations, as shown in FIG. 1a.
A first ESD protection device 16 for protecting ESD of the power source pad 11 and the I/O pad 13 is connected between the power source pad 11 and the I/O pad 13. A second ESD protection device 17 for protecting ESD of the ground pad 12 and the I/O pad 13 is connected between the ground pad 12 and the I/O pad 13. A third ESD protection device 18 for protecting ESD of the power source pad 11 and the ground pad 12 is connected between the power source pad 111 and the ground pad 12.
This kind of the mode is advantageous in that it can implement relatively stable ESD protection for the entire I/O cells, but is disadvantageous in that two ESD protection devices have to be separately disposed in one I/O cell. Moreover, there is a problem in that lots of a layout area is taken because an ESD protection device such as a power clamp must be disposed between the power source pad and the ground pad. Furthermore, if the power clamp is not properly disposed between the power source pad and the ground pad, there is a possibility that problems can be generated in a core circuit because ESD stress applied between the two pads is introduced into the core circuit.
Accordingly, the conditions that an ESD protection device and an ESD protection structure, which need to be developed in order to solve the problems of the existing ESD protection structure, are as follows.
(1) It is required that one ESD protection device can protect the six ESD stress modes, which can occur in the respective I/O cells. More particularly, it is required that one ESD protection device cope with ESD protection between the power source pad and the ground pad even without the power clamp.
(2) It is required that the current immunity level of an ESD protection device corresponding to the six ESD stress modes be sufficiently high.
(3) It is required that the output buffer and the input buffer of the I/O cells be efficiently protected against the six ESD stress mode. To this end, a triggering voltage of the ESD protection device has to be similar to a BJT triggering voltage of a PMOS transistor and an NMOS transistor of each output buffer in a corresponding ESD stress mode. It is also required that an ESD stress voltage be lowered lower than the breakdown voltage of a gate oxide film.
(4) Additionally, it is required that a core circuit, an output buffer and an input buffer be protected against the pin-to-pin mode ESD stress in which ESD stress is added between the I/O cells and the I/O cell.

Device for electrostatic discharge protection and circuit thereof


The water-soluble electrically-conductive polyaniline of this invention is such that the aromatic rings of the skeleton thereof are substituted by an average of 0.1-4 sulfonic acid (salt) groups and an average of 0-3.9 H's or other substituents (providing that the total of the number of sulfonic acids (salts) and that of other substituents is 4) per aromatic ring and 0.025-1 nitrogen atom of each of the nitrogen atoms in the main skeleton is doped with an external dopant. It is obtained by causing polyaniline to react with chlorosulfuric acid and then subjecting the reaction product to hydrolysis.. The antistatic agent of this invention is formed by using a water-soluble electrically-conductive polymer which has been doped with an external dopant.

1. Field of the Invention
This invention relates to a water-soluble electrically-conductive polyaniline and a method for the production thereof. The aqueous solution of the water-soluble electrically-conductive polyaniline is useful for preparing a commercially acceptable thin films by such a simple procedure such as spin coating, dip coating, or bar coating. The water-soluble electrically-conductive polyaniline can be utilized for various antistatic devices, transparent electrodes, shields against electromagnetic radiation, photovoltaic elements, organic electroluminescent elements, organic electrochromic elements, corrosion inhibitors, semiconductor photocatalysts, photoresists, nonlinear optical materials, and the like.
This invention further relates to an antistatic agent using a water-soluble electrically-conductive polymer. The aqueous solution of the antistatic agent is useful for preparing commercially acceptable thin films with fast and strong adhesion to polymer films, polymer fibers, and moldings of polymer resins by a simple procedure such as spin coating, dip coating, or bar coating. Further, the antistatic agent manifests excellent antistatic effects even under low humidity.
2. Description of the Prior Art
First, since the doped polyaniline is stable as an electrically-conductive polymer and derives from inexpensive raw materials, the development of the applications thereof to film electrodes, secondary batteries, capacitors, antistatic agents, shields against electromagnetic radiation, etc. is being promoted. However, the insoluble and infusible character of polyaniline prevent easy formation or fabrication. The solubilization of the polyaniline, therefore, is significant from the commercial point of view. From the standpoint of handling in a factory, solubility in water provides many advantages over solubility in other solvents.
Second, since polymer films, polymer fibers, moldings of polymer resin, etc. are electrical insulators, they tend to buildup static electricity to the extent of breaking electronic components, attracting dust, and possibly causing a fire. Thus, a solution of these issues is essential. Heretofore, surfactants have been mainly used as antistatic agents. Since surfactants show ionic conduction by moisture in the air, it is difficult to lower the surface resistance below 10.sup.9 (.OMEGA.,.quadrature.) and still keep the antistatic effect tinder the condition of low humidity.
Another electron-conductive antistatic agent has also been known, where carbon black, fine powder of metals such as aluminum, copper, or silver, and fine powder of semiconductors such as indium tin oxide or fluorine-doped tin oxide are dispersed as fillers in a general-purpose polymer. Using these fillers, however, causes problems such as (1) fairly large amounts of fillers are required, (2) controlling the electric resistance is difficult because the electric resistance may suddenly decrease at certain amounts of filler addition, (3) the fillers will gradually come out to the surface of a coating film with age, preventing the film from acquiring a smooth surface, (4) the film has inferior transparency, and (5) the strength of the coating film is low.
Though the electrically-conductive polymers have a bright prospect of solving these problems, they are generally at a disadvantage in being neither moldable nor processible because of their insolubility and infusibility. The doped polyaniline, among other electrically-conductive polymers, features stability in the air, inexpensiveness of the raw materials and suitability for the development of applications. Polyaniline is insoluble and infusible, however, like other electrically-conductive polymers. Therefore, the solubilization of polyaniline is commercially significant. From the view points of handling in a factory, using water to dissolve polyanitive provides many advantages such as cost and safety compared to using organic solvents.
For the doped polyaniline which is useful for film electrodes, secondary batteries, capacitors, antistatic agents, shields against electromagnetic radiation, etc. and for the electrically-conductive polymers, particularly the doped polyaniline, which are useful for polymer films, polymer fibers, molding of polymer resin, etc., the necessity for improving the solubility of polyaniline in water has been getting attention.
For the purpose of improving the solubility of polyaniline in water, various methods for the introduction of a sulfonic group to the polyaniline have been proposed in recent years. Methods for polymerizing aminobenzene sulfonic acid as a monomer have been known such as, for example, synthesizing sulfonated polyaniline by electrochemically copolymerizing aniline with o- or m-aminobenzene sulfonic acid (Journal of Japan Chemical Society, 1985, p. 1123 and JP-A-02-166,165), copolymerizing aniline with aminobenzene sulfonic acid by chemical oxidation (JP-A-01-301,714 and JP-A-06-56,987), sulfonating the copolymer of aniline with aminobenzene sulfonic acid and a derivative thereof (JP-A-05-18, 989), polymerizing o-, m-aminobenzene sulfonic acid by electrochemical oxidation (Glossary II of Lecture Prescripts of the 64th Autumnal Annual Meeting of Japan Chemical Society, p. 706, 1992), and polymerizing o-, m-aminobenzene sulfonic acid and a derivative thereof by chemical oxidation (JP-A-07-324,132 and JP-A-08-41,320).
Further, methods for introducing a sulfonic group into the polyaniline through the medium of a sulfonating agent have been proposed such as, for example, sulfonating an emeraldine salt by the use of sulfuric anhydride/triethyl phosphate complex (JP-A-61-197,633), sulfonating undoped polyaniline (emeraldine base) by the use of fuming sulfuric acid (WO91-06887, J. Am Chem. Soc., 1990, Vol. 112, p. 2800, J. Am. Chem. Soc., 1991, Vol. 113, p 2665), sulfonating undoped polyaniline (emeraldine base) in chlorosulfonic acid (Polymer, 1991, Vol. 33, p 4410), and a method for sulfonating the polyaniline of a leucoemeraldine base with fuming sulfuric acid (J. Am. Chem. Soc., 1996, Vol. 118, p 2545).
The method for copolymerizing aminobenzene sulfonic acid and a derivative thereof with aniline by electrochemical or chemical oxidation, however, is barely capable of introducing sulfonic groups at a ratio of one sulfonic group to five aromatic rings. The product of this method, has a solubility problem because it is insoluble in water while it is slightly soluble in aqueous alkalis. Then, the method which further sulfonates such a copolymer is shown to introduce sulfonic groups at a ratio of slightly over one sulfonic group to two aromatic rings. The product of this method also has a solubility problem because it is insoluble in water though it is soluble in aqueous alkalis.
The method for polymerizing o-, m-aminobenzene sulfonic acid by electrochemically oxidation, in spite of the previous statement that the method has produced a water-soluble electrically-conductive polymer, has such problems that the method is not suitable for the manufacture on a commercial scale because the polymerization is an electrode reaction and isolation of the product is difficult. When the method for polymerizing o-, m-aminobenzene sulfonic acid and a derivative thereof in an acidic solution by chemical oxidation or a basic solution by chemical oxidation is verified, it is found to yield a reddish brown oligomer and to not form a sulfonated polyaniline in the state of an emeraldine salt as the repeating unit thereof. It is generally difficult to obtain a polyaniline of high molecular weight with green color which is characteristic for the emeraldine salt by polymerizing an aniline monomer possessing a substituent.
In the methods for introducing a sulfonic group by the use of a sulfonating agent, the method which sulfonates a polyaniline by the use of a sulfuric anhydride/triethyl phosphate complex barely introduces sulfonic groups at a ratio of one sulfonic group to five aromatic rings. The compound produced by this method, shows no solubility in water in the doped state. The method of the sulfonation by the use of fuming sulfuric acid affords a self-doped polyaniline with sulfonic groups at a rate of one sulfonic group to two aromatic rings. The polyaniline, however, is insoluble in neutral to acidic aqueous solutions because the sulfonic groups are utilized for doping the aniline. It, therefore, must react with an alkali to become soluble in the aqueous solutions. The polyaniline generally turns into an insulator when it reacts with an alkali. The self-doped polyaniline, therefore, does not fully satisfy needs of moldability and processibility because it must be redoped after processing.
The method of sulfonation by chlorosulfuric acid affords a self-doped polyaniline with four sulfonic groups per five aromatic rings. This polyaniline, however, is insoluble in neutral to acidic aqueous solutions because the sulfonic groups are utilized for doping the aniline and must react with an alkali to become soluble in the aqueous solutions. Thus, it is not suitable for processing. The method which sulfonates the polyaniline of a leucoemeraldine base with fuming sulfuric acid yields polyaniline with three sulfonic groups per four aromatic rings. Since this product is a self-doped one, it is only slightly soluble in water and is problematic in terms of solubility and processibility.
Further, in the methods of the sulfonation by the use of fuming sulfuric acid and chlorosulfuric acid mentioned above, since they use a large excess of the sulfonating agent relative to the amount of polyaniline, they have the problem of having to dispose a large amount of used acid.
Water-soluble polyanilines in the electrically conductive state have been known, including, namely in the doped state, N-sulfonated polyaniline resulting from the chemical oxidative polymerization of diphenyl amine-4-sulfonic acid (Polymer, 1993, Vol. 24, p. 158), N-propane sulfonic acid-substituted polyaniline resulting from the reaction of polyaniline with 1,3-propane sultone (J. Am. Chem. Soc., 1994, Vol. 116, p. 7939 and J. Am. Chem. Soc., 1995, Vol. 117, p. 10055), and phosphonated polyaniline resulting from oxidative polymerization of o-amino-benzyl phosphonic acid (J. Am. Chem. Soc., 1995, Vol. 117, p. 8517).
The isolation of the N-sulfonated polyaniline, however, is extremely complicated because the polymer possesses such high solubility as to necessitate high-speed centrifugation after the polymerization. Then, since the N-propane sulfonic acid-substituted polyaniline is a self-doped polyaniline and is insoluble in water in the doped state, it cannot be soluble in water in the doped state unless by a method of treating the aqueous solution of a sodium salt thereof with an ion-exchange resin. Thus, it has the problem of having no alternative but to use a very complicated procedure in terms processiblility. The phosphonated polyaniline has the problem of being unusually complicated from the commercial point of view because the production of the o-aminobenzyl sulfonic acid, the raw material for polymerization, requires several steps of reactions.
A water-soluble polyaniline in the conducting state, namely in the doped state, a method for producing this polyaniline with a simple procedure, and an antistatic agent using such a water-soluble electrically-conductive polymer as the polyaniline have never been heretofore known to the art.
The first object of this invention, therefore, is to provide a novel water-soluble electrically-conductive polyaniline and a method for the production thereof.
The first object of this invention also resides in providing a polyaniline which is soluble in water in the state having high electrical conductivity, namely in the doped state, and a method for the production thereof.
The second object of this invention is to provide, by using preferably the novel water-soluble electrically-conductive polyaniline (such as, for example, sulfonated polyaniline) mentioned above as a polymer soluble in water in the state having high electrical conductivity, namely in the doped state, an antistatic agent with lower resistance which retains the effect thereof even at and lower humidity than prevalent heretofore, excels in coating property and adhesiveness to a substrate, and enjoys fully satisfactory strength, transparency, and waterproofness after application to a surface.

Water-soluble electrically-conductive polyaniline and method for production thereof and antistatic agent using water-soluble electrically-conductive polymer


A device is configured to detect that a user device has failed to receive a call attempt for a call intended for the user device and from a calling party, and determine, based on the detection, that the calling party has not left a voicemail message associated with the call. The device is configured to store missed call information, associated with the call, and send a first missed call notification to the user device, where the first missed call notification includes the missed call information. The device is configured to detect that the user device has not received the first missed call notification, and send a second missed call notification to the user device, where the second missed call notification includes the missed call information.

Communication devices, such as cellular phones, may receive calls from other communication devices via a communication network. A receiving communication device may fail to connect to a calling communication device when the receiving communication device is not connected to the communication network at the time of the call. For example, the receiving communication device may be powered off, malfunctioning, and/or outside of a network service area.


Aspects of this disclosure provide techniques for generating a viseme and corresponding intensity pair. In some embodiments, the method includes generating, by a server, a viseme and corresponding intensity pair based at least on one of a clean vocal track or corresponding transcription. The method may include generating, by the server, a compressed audio file based at least on one of the viseme, the corresponding intensity, music, or visual offset. The method may further include generating, by the server or a client end application, a buffer of raw pulse-code modulated (PCM) data based on decoding at least a part of the compressed audio file, where the viseme is scheduled to align with a corresponding phoneme.

Traditional methods for learning a language, in particular a foreign language, are typically not enjoyable for students. Students may spend most of the time learning rules of grammar and syntax and memorizing words in the target language (the language being learned). The students are generally not exposed to correct pronunciation except for a recording of the target language. This type of approach generally does not enable the language learner to converse fluently in the target language.


A cooling system of a battery which efficiently cools a high voltage battery which is mounted in an electric vehicle or a hybrid vehicle so as to maintain battery performance by using a refrigeration cycle of an air-conditioning system, which is provided with an electric compressor, outside heat exchanger, inside heat exchanger, and a control device. A refrigerant path of the air-conditioning system for running refrigerant is provided with a branch path having a heat exchanger which bypasses the inside heat exchanger, a medium path connected to the heat exchanger runs another refrigerant for cooling the battery, control valves are provided which adjust the amounts of the refrigerant which flows to the refrigerant path and the branch path, and, when the control valves run the refrigerant to both the refrigerant path and the branch path, the control device increases the speed of the electric compressor.

1. Field of the Invention
The present invention relates to a cooling system of a battery which cools a battery, which supplies electric power to a drive-use electric motor, by utilizing a refrigerant of an air-conditioning system which is mounted in the vehicle. A vehicle which mounts a drive-use electric motor is either an electric vehicle or a hybrid vehicle. The present invention relates to a cooling system of a battery which is designed to not detract from the comfortable feeling of air-conditioning given to the passengers by the air-conditioning system.
2. Description of the Related Art
In recent years, electric vehicles (EV) and hybrid vehicles (HV) have been commercialized. Along with this, the capacity of the batteries which supply electricity to the drive-use motors which are mounted in these vehicles has become larger and the output voltage has become higher. Further, an HV or EV carries a large number of batteries for use as sources of drive power, so the battery performance is important. To enable the batteries to exhibit their performance in full, it is important to hold the battery temperature at a suitable level.
On the other hand, in an HV or an EV, heat is generated at the time of charging the battery. In such a case, sometimes the battery becomes high in temperature. To secure the battery performance, the battery has to be cooled. For cooling the battery of a vehicle powered by a conventional internal combustion engine, air cooling by the natural flow of air was sufficient, but for cooling a high voltage battery with a voltage of 12V or higher which is mounted in an HV or an EV, air cooling by the natural flow of air is not sufficient.
Therefore, a battery cooling system which uses a refrigeration cycle of a vehicular air-conditioning system in an HV or EV so as to efficiently cool the battery is disclosed in Japanese Patent Publication (A) No. 2001-105843. In the battery cooling system which is disclosed in Japanese Patent Publication (A) No. 2001-105843, a battery cooler which is comprised of a base and a plurality of heat conduction fins is prepared, the battery is placed between two heat conduction fins, and the refrigerant which is used in the refrigeration cycle of the air-conditioning system is branched off and run to a refrigerant passage which is provided inside of the base so as to thereby cool the battery.
However, in the battery cooling system which is disclosed in Japanese Patent Publication (A) No. 2001-105843, while the refrigerant which is used in the refrigeration cycle of the air-conditioning system is being run to the battery cooler, the refrigerant is not being run to the air-conditioning system side. For this reason, in the battery cooling system which is disclosed in Japanese Patent Publication (A) No. 2001-105843, there was the problem that the cooling capacity of the air-conditioning system ended up falling at the time of cooling the battery and the venting temperature of the cooling air to the passenger compartment from the air-conditioning system ended up rising.


An electronic device may be provided with a display. Backlight structures may be used to provide backlight for the display. The backlight structures may include a light guide plate. A rectangular ring-shaped chassis may have a rectangular opening that receives the light guide plate. One or more edges of the chassis may be provided with an array of notches that receive light-emitting diodes or other light sources. The light sources may launch light into edge portions of the light guide plate. The chassis may include a first plastic structure such as a light reflecting structure formed from a material such as white plastic. The first plastic structure may surround two or more peripheral edges of the light guide plate. The chassis may also include a second plastic structure such as a light blocking structure formed from a material such as black plastic that helps prevent light leakage.

This relates generally to electronic devices and, more particularly, to displays for electronic devices.
Electronic devices such as cellular telephones, computers, and media players often contain displays. For example, electronic devices often include backlit displays such as backlit liquid crystal displays.
Backlit displays generally include a light distribution layer called a light guide plate. The light guide plate is typically formed from a rectangular sheet of clear plastic that has been injection molded, extruded, or die cut from a sheet of plastic. Light from an array of light-emitting diodes may be launched into the edge of the light guide plate. The light guide plate distributes light across the back of a display panel by total internal reflection. Light that exits the planar upper surface of the light guide plate serves as backlight for the display panel.
The light guide plate is typically mounted within a white plastic chassis structure that is sometimes referred to as a p-chassis or moldframe. The white plastic of the p-chassis forms reflective sidewalls around the periphery of the light guide plate. Light that exits the edges of the light guide plate is reflected back into the light guide plate by the reflective sidewalls of the p-chassis. The reflected light may therefore serve as additional backlight for the display.
The use of reflective white plastic to form the p-chassis can improve backlight efficiency. However, the white plastic that forms the sidewalls of the p-chassis is generally unable to block all of the light that strikes the sidewalls. As a result, some of the light from the light guide plate can leak into undesired areas of an electronic device. If care is not taken, for example, leaking light may cause unwanted illumination in locations that are visible to a user of an electronic device.
It would therefore be desirable to be able to provide improved display backlight structures such as improved chassis structures for light guide plates in display backlights.


It has a gradation voltage generation circuit 1 for generating a plurality of voltage values suited to gamma characteristics of a liquid crystal and so on, a digital image data storage circuit 3 for storing digital image data displayed on a display device, a gradation voltage selection circuit 2 for selecting one value according to digital data stored by the digital image data storage circuit 3 from the plurality of voltage values generated by the gradation voltage generation circuit 1, an amplifier 4 for receiving a voltage selected according to the digital image data and driving a data line of the liquid crystal and so on at a predetermined voltage, a voltage detection circuit 7 for detecting voltage variations of the amplifier 4, a correction data storage circuit 6 for storing a state of the voltage variations of the amplifier 4, and a voltage correction circuit 5 for correcting output voltage variations of the amplifier 4.

1. Field of the Invention
The present invention relates to a driver circuit of a display device, and in particular, to the driver circuit of the display device of a self-luminous type such as an organic EL (Electro Luminescence) of which output precision is required.
2. Description of the Prior Art
It is a known fact in recent years that an information electronics device such as a portable telephone is widely used in the world. It is also well known that the information electronics device has a self-luminous type display device such as an organic EL as its display apparatus. A matrix type display device is also well known as one of the representatives of the self-luminous type display devices such as the organic EL.
The display device shown in FIG. 1 or FIG. 2 is also known as such a matrix type display device, for instance.
The matrix type display device in the past 2100 shown in FIG. 1 has a configuration wherein a plurality of data lines (not shown) connected to a data line driver circuit 2103 and a plurality of scanning lines connected to a scanning line side driver circuit 2102 are provided, and a display panel 2101 having a liquid crystal, the organic EL and so on is provided at each intersection thereof.
The matrix type display device in the past 2200 shown in FIG. 2 has a configuration wherein a plurality of data lines (not shown) connected to a data line driver circuit 2203 and a plurality of scanning lines connected to a scanning line side driver circuit 2202 are provided, and a display panel 2201 having the liquid crystal, organic EL and soon is provided at each intersection thereof.
FIG. 3 is an equivalent circuit diagram of a TFT (Thin Film Transistor) liquid crystal cell 1701 using a TFT 1703 as an active element, wherein transmittance is controlled by voltage. FIG. 4 is an equivalent circuit diagram of an organic EL cell 1801 using two TFTs (1803, 1806), wherein luminance is controlled by voltage. FIG. 5 is an equivalent circuit diagram of a simple matrix type organic EL cell 1901, and FIG. 6 is an equivalent circuit diagram of an organic EL cell 2001 using four TFTs (2003, 2006, 2008, 2009), wherein luminance is controlled by currents.
A voltage-control type data driver circuit 1400 of the matrix type display device in the past selects on a gradation voltage selection circuit 2 one voltage value, according to digital image data, of a plurality of voltages generated on a gradation voltage generation circuit 1 (refer to FIG. 7) so as to drive the data lines via an amplifier 4.
When the number of bits of the digital image data increases, the gradation voltage selection circuit 2 increases impedance in order to reduce the area of constituting elements because a chip-occupied space thereof becomes larger in proportion to the number of bits. For that reason, the data lines are driven by having the voltage selected on the gradation voltage selection circuit 2 impedance-converted by an amplifier 4.
In general, a liquid crystal display has a driving voltage range of 3 to 5V, and the digital image data is 4 to 6 bits in the case of the portable telephone and so on.
And a current-control type data driver circuit drives the data lines with a plurality of weighted current sources 31 as shown in FIG. 8.
The data driver circuit of the display device is generally integrated, and has the same number of output terminals as the number of horizontal data lines of the display device. Or in the case where a plurality of data lines are connected to one driver circuit in parallel as shown in FIG. 2, the data driver circuit of the display device has the number of output terminals which is the number of pixels/the number of parallels added thereto, so that the number of the output terminals thereof becomes a few tens to a few thousands or more. As for semiconductor equipment and so on, manufacturing variations cause voltage variations and current variations.
For that reason, Japanese Patent Laid-Open No. 4-142591 proposes a method of, in order to reduce output voltage variations of the data driver circuits of the liquid crystal display device, having the data of which output voltage variations are to be corrected stored by storage circuit in advance and driving the liquid crystal with a signal wherein the data of the storage circuit in synchronization with a clock signal is added to a picture signal.
However, the following problem arises as to the method of adding the digital image data and correction data as with the data driver circuit of the liquid crystal display described in Japanese Patent Laid-Open No. 4-142591.
In the case of the liquid crystal display, a voltage difference capable of recognizing display variations of the liquid crystal is approximately 5 mV or so. In the case where the driving voltage range of the liquid crystal is 3V, it is 3000 mV/5 mV=600 and precision of 9 bits (512-value) or higher is required. To be more specific, 9-bit or more correction data is necessary to correct the voltage variations of the driver circuits.
Even in the case where the digital image data is 6 bits, the circuits from an addition circuit onward are 9 bits or more, and so the circuit scale of the data driver circuit becomes larger.
In addition, a voltage-to-transmittance property of the liquid crystal (FIG. 9) and a voltage-to-luminance property of the organic EL (FIG. 10) are nonlinear and so a correction amount is different according to the voltage. Therefore, as the digital image data cannot be simply added to the correction data, the correction data for each piece of the digital image data is required and thus a correction data storage circuit becomes even larger.
An organic EL display device has a luminance-to-current property which is linear, and so it is driven by the plurality of weighted current sources. In this case, as can be easily presumed from Japanese Patent Laid-Open No. 4-142591, there is a thinkable method of correcting the current value by storing the data for correcting output current variations in advance. However, there are the cases where, as each of the weighted current sources varies independently, a monotone increase property is lost, and the correction data storage circuit becomes enormous because each bit of the digital image data requires the correction data.
Furthermore, the variations at the time of manufacturing are stored in an ROM or the like in order to store the variations in the driver circuits as the correction data in advance, so that the variations cannot be corrected against the change in use conditions (change in temperature and change over time)


Apparatus for extracting light from an optical waveguide (12) by bending the waveguide to such an extent that a portion of any light propagating in the waveguide leaks therefrom comprises a bending unit (10) for bending a portion of the waveguide in dependence upon a control signal (S) and providing a detection signal (Pd) proportional to light leaked from the waveguide. A control unit (14) varies the control signal (S) in response to the detection signal (Pd) to cause the bending unit (10) to progressively decrease the bending angle and has a processor unit (46) which computes a rate of change (dPd/dR) of the detection signal (Pd) with respect to bending radius (R) and causes the bending unit to maintain that bending radius at which the aforesaid rate of change is substantially equal to a predetermined value.

It is often necessary to be able to detect a signal in an optical waveguide by extracting a portion of the light being guided. For example, it is useful to be able to distinguish between live (signal carrying) and dark (no signal) optical waveguides, to be able to extract a signal for sampling, to perform an approximate measurement of the guided optical power, to perform accurate differential measurements of the guided optical power before and after a possible localized loss such as a splice, and to determine the direction of traffic. It is desirable to perform these operations without disrupting, overly attenuating or distorting the signal, especially in telecommunications systems, as the margins with which many such systems operate often do not permit more than about one decibel of additional attenuation without the risk of inducing errors to the transmission, thereby leading to potential traffic interruptions and even system shutdowns.
It is well known that light can be extracted from an optical waveguide such as an optical fiber by bending it so that a fraction of the guided light leaks from the waveguide. The extracted light is known as the bending loss. Devices for bending optical fibers to extract light in this way are often referred to as "optical fiber taps" and may use "micro-bends" or "macro-bends". U.S. Pat. No. 5,708,499, for example, discloses the use of both micro-and macro-bends,
However, in most central office and outside plant applications, optical fiber is cabled, i.e. protected by one or both of a buffer material (typically silicon or epoxy resin) and a plastic jacket (usually PVC or polyethylene). Various cable types are common, but jacketed cables with a 3-mm diameter and tight-buffered fiber with a 900-micrometer nominal diameter are among the most common. It is not practical to apply micro-bends to such a jacketed or buffered fiber.
Macro-bends have a radius of curvature that is much larger than the waveguide diameter. When such a bend is applied to an optical fiber, it causes a significant amount of the light to leak out, even if the fiber is cabled. Moreover, in most cases, both the buffer coating and jacket materials have some degree of transparency at the near-infrared wavelengths used in telecommunication systems, permitting a non-negligible fraction of the leaked light to be detected externally.
For a given fiber, the degree of macro-bending required to detect a certain amount of leaked light is strongly dependent upon the wavelength. Less bending is required for longer wavelengths and more bending is required for shorter wavelengths. For a given wavelength, the required detection sensitivity is also dependent upon fiber type and the types and colors of the coatings and jackets protecting the fiber. The performance of a macro-bending device for signal detection is largely dependent upon the amount of light that is extracted, which is directly proportional to the induced attenuation of the guided light ("insertion loss"). Clearly, if the guided signal power is low, it is desirable to bend the waveguide to a relatively tight radius so as to extract as much signal as possible, but without exceeding the loss margin of the system, distorting the signal or even causing physical damage to the fiber. It is desirable, therefore, to control the bending radius carefully.
It is known for so-called "clip-on" devices to employ macro-bending means to extract a portion of the guided light from an optical waveguide and detection means to determine the amount of extracted light. However, almost all of the prior art is limited to macro-bending introduced by a fixed bending structure, i.e. where the bend radius is either not changed, or where a portion of the escaping light detected is not detected while the bend radius is changed (during the cable clamping process, for instance).
Among this fixed-bending-structure prior art, macro-bending devices are known which take account of the different fiber, jacket, and coating types. One such device is marketed by EXFO Electro-Optical Engineering Inc. under the product name LFD-200 live Fiber Detector. This clip-on device comprises a so-called "fixed" bending means with a set of interchangeable heads of different shapes and sizes over which the fiber is bent to a fixed bending radius. A disadvantage of this approach is that the insertion loss caused by this fixed macro-bending is strongly dependent upon wavelength, making it impractical to optimize both the insertion loss and sensitivity when the wavelength of the propagating light could be, say, 1310 or 1550 nm. Another disadvantage of this device is that the technician who is using the device has to change the device head manually for each fiber type. The use of the device is therefore limited to the set of cable types and wavelengths for which the set of interchangeable heads are designed.
In another known macro-bending device, disclosed in U.S. Pat. No. 4,671,653, the level of detected light is compared to a predetermined threshold determined by the fixed bending structure, and, if this threshold is reached, an indicator light turns on. A disadvantage of this device is that the level of detected light will be dependent upon factors such as the optical power in the fiber, the fiber type, and the wavelength, as well as the amount of absorption and scattering that occurs as the light passes through coatings and jackets. Hence, the choice of a threshold value is very approximate and depends, upon the particular application. Moreover, there is, in general, no information as to the macro-bending-induced insertion loss.
U.S. Pat. No. 5,781,285 discloses an optical fiber tap which, in order to avoid mechanical damage to the fiber, progressively decreases the bending radius of the fiber under test by means of a probe that pushes laterally against the fiber. The primary purpose of this device is to detect the presence or absence of light in the fiber. This device can be used with various fiber types, as several different concave areas having different radii of curvature may be offered on the bottom plate of the instrument to introduce respective macro-bends. A probe is used to push against the fiber, and a detector is located in the probe. It is noted that the use of different concave areas is functionally equivalent to the use of interchangeable heads in the aforementioned EXFO instrument. In the absence of knowledge of fiber type, wavelength, and optical power in the fiber, the macro-bending-induced insertion loss of this device could lead to excessive loss and hence possible system failure.
European patent No. 0639762 also discloses an optical fiber tap which applies a macro-bend, but makes use of a damping mechanism to limit the abruptness with which this macrobend is applied, thereby reducing the chance of fiber damage and, in the case of a live transmission system, thereby reducing the risk of an error burst during application. However, there is no information as to the macro-bending-induced insertion loss and this device could lead to excessive loss and hence possible system failure.
Other known macro-bending devices involve winding the optical fiber around a mandrel. European Patent No. 0361962 discloses such a fiber tap which winds the fiber around a conical mandrel. The bending radius is gradually reduced as the mandrel is rotated about its axis until some leaked light is detected by a detector, or until a predetermined maximum level of bending is reached. A disadvantage of this device is that, after the fiber has been bent enough for some light to be extracted, light is being leaked along a section of fiber that is longer than necessary for detection purposes. As a result, a large proportion of this light is not detected and is therefore wasted. As before, any measurements taken with this device must be calibrated for fiber type and wavelength, as well as jacket and buffer coating type, and, in the absence of any of this knowledge, it is not possible to derive the macrobend-induced insertion loss.
More recently, U.S. patent application Ser. No. 2005/0041902 (Frigo et al.) disclosed a method and apparatus for identifying an optical fiber by applying time-varying modulation to an optical signal propagating through the fiber. A transmitter, for example a vibrating piston contacting the fiber laterally, applies the time-varying modulation at a first location, and a downstream receiver extracts light by bending the fiber around a mandrel to extract a portion of the signal, and detects the time-varying modulation in the extracted portion.
As in the case of the aforementioned EXFO device, Frigo et al.'s primary embodiments use interchangeable mandrels or "anvils", each characterized by a different radius of curvature. As explained above, the use of such mandrels is inconvenient in the field, particularly when the technician is not certain of the wavelength or power level in the fiber under test.
Frigo et al.'s primary aim is to detect the presence of the modulation signal on the light propagating in the fiber while minimizing the intrusiveness of the measurement. Consequently, they seek to extract a minimal amount of the light from the fiber, i.e., only enough to enable detection of the time-varying signal, so as to ensure that insertion loss limits are not exceeded. In the absence of knowledge of the optical power in the fiber, the fiber type and wavelength information, however, it is not possible to derive the actual value of the macrobend-induced insertion loss and, hence, be assured that insertion loss limits are not being exceeded.

Method and apparatus for extracting light from an optical waveguide


The present invention relates to oil toilets where oil is used as a sealant to isolate unpleasant smell produced by waste materials. Waste materials enter oil in the storage container and sink since both solid waste and urine have specific gravity that is higher than that of oil. Excess oil is collected in the overflow container. It has a component for collection of fumes that are formed by the waste materials collected in the toilet. A cleaning means is utilized to remove waste materials from the toilet while at the same time it could be modified to reuse a substantial amount of the oil present in the toilet.

This invention relates to a waste storage systems and particularly to toilets for humans and pets.
Toilets have been in use for centuries. They provide a convenient way for attending to biological needs and for storing away of waste materials. However, most cat litter boxes are only marginally effective in isolation of unpleasant odors. This problem is also present in many types of portable toilets for human use. In addition, regular toilets used in people""s homes operate on principle of using large amounts of water to flush waste products. Therefore, there exists a problem with prior art toilets due to a fact that they are either ineffective in containment of unpleasant odors or utilize a lot of water. In addition, most cat litter boxes require manual cleaning which exposes person cleaning them to unpleasant odors.
What is needed is a simple, easy to use toilet that could be modified to be used for either pets or humans and which would prevent escape of unpleasant odors into ambient environment. A desired toilet should use little or no water so as to conserve water supplies. Moreover, such toilet should be easy to clean, requiring minimal and simple maintenance.
This invention satisfies the above needs. A novel toilet is provided.
The claimed toilet is based on a principle of using any type of oil for containment of the waste materials. The oils is used as a sealant. Waste materials enter oil and sink since both solid waste and urine have specific gravity that is higher than that of oil. Thus there is creation of a layer of oil over the waste materials making oil into a sealant that prevents escape of unpleasant odors into the ambient environment. In addition, present invention is designed to collect excess oil to prevent it from spilling out of the toilet. It has a component for collection of fumes that are formed by the waste materials collected in the toilet. A cleaning means is utilized to remove waste materials from the toilet while at the same time allowing for reuse of a substantial amount of the oil.

Self-cleaning, waste storing, odorless, environmentally friendly toilet for humans and animals


An automatic injection device has an insertion needle configured to be inserted into a patient and a drug container which contains a pharmaceutical product. The drug container includes a stopper. The automatic injection device also has a fluid path which fluidly connects the drug container to the insertion needle. The automatic injection device further has a drive system configured to cause parallel linear movement of the stopper to force the pharmaceutical product into the fluid path. The drive system has a driving element and a movable element. The automatic injection device additionally has electronics configured to provide a signal to the drive system to move the stopper and have means for sensing the stopper position. The movable element has an outer magnet at least partially surrounding the drug container and an inner magnet inside the drug container.

Injection devices are used to deliver pharmaceutical products such as biologics and medications to a patient (i.e., a person or animal). A syringe and needle is an example of a widely-used injection device. This basic system typically involves a person manually moving a stopper portion of the syringe to force the pharmaceutical product through the needle and into the patient. Other injection devices have been developed to deliver pharmaceutical products automatically at the touch of a button or the actuation of a switch. These devices are advantageous in that they allow a patient to more easily self-administer the pharmaceutical product. Moreover, some automatic injection devices allow for slow or periodic delivery of the pharmaceutical product as needed, which is typical procedure for patients dependent on insulin injections, for example.
However, there is a need for automatic injection devices to provide injection control in a compact device such that the device is easy to handle and discrete for a patient who may wear the device for an extended period of time.
The present disclosure is directed to an automatic injection device which addresses these needs and the associated problems of the prior art.

Automatic injection device having a magnetic drive system


The present invention is directed to a removable magnetic clasp for eyeglasses. The eyeglasses have a right temple bar and a left temple bar pivotally attached to an eyeglasses frame body. The magnetic clasp comprises: a first connector and a second connector; a first magnet being positioned on the first connector and a second magnet being positioned on the second connector. A channel extends through a portion of each connector and the channel is configured to so as to allow a temple bar to slide through the channel. The removable magnetic clasp, when attached to eyeglasses, allows for the first and second magnets to remain in attractive magnetic communication when the temple bars are closed but separated by clothing material, the attractive magnetic communication imparting a gripping force on the clothing material sufficient enough to substantially prevent relative movement between the temple bars and the clothing material.

Typical eyeglasses consist of a frame body that houses two lenses on either side of a nose piece. Attached to the frame body are two temple bars that extend from two ends of the frame body. The temple bars pivot between an open position perpendicular with the frame body and a closed position parallel with the frame body. Sometimes attached to the temple bars are separate ear pieces, or temple tips. The temple bars and nose piece support the frame on the head of the wearer.
Individuals often remove their eyeglasses temporarily. They may put them down and not recall where, they may hang them around their neck where they bounce against their chest, or they may put them in a pocket and have them fall out and/or get damaged.
To solve this problem, the prior art teaches using mechanical clasps to clip eyeglasses to a garment worn by the user. These are cumbersome and, like all mechanical clasps, may come loose. Some mechanical clasps also depend on the availability of a shirt pocket, a cap visor, belt, holder, straps, or the like. In addition, clips may work well initially, but fatigue can cause metal clips to weaken and lose their ability to hold eyeglasses securely. Moreover, clips can break, thereby causing the eyeglasses to come loose, fall and break, or be lost. U.S. Pat. No. 6,017,120 to McCormick teaches a mechanical clip attached to the hinged end of the temple bars. Eyeglasses using such mechanical clips may not be securely held in place when inverted, such as when a person bends over at the waist. Another problem with such clips arises when a person in a sitting position bends forward, and the eyeglasses are pushed upward while clasped inside a shirt pocket. In that situation, the clip may be pushed up from the bottom of the pocket, thereby disengaging the clip and causing the eyeglasses to fall from the pocket.
The use of magnets on eyeglass frames for various purposes is also well known in the art. For example, a number of eyeglass frames have magnets that magnetize the wearer for health benefits. Other eyeglass frames use magnets to hold eyeglass frame sections together, thereby facilitating disassembly and reassembly in a new configuration, with auxiliary frames, lenses, or the like. U.S. Pat. No. 6,168,273 B11 to Dupraz et al. teaches the use of magnets on eyeglass frames to temporarily affix the eyeglasses on a support article having magnetic means. Because the magnets in Dupraz et al. are attached to the temple bar near the hinges, however, its teaching cannot be used as a magnetic clasp, nor was it intended as such.
It would be desirable to provide a removable magnetic eyeglasses clasp that could be easily attached to eyeglasses frames that would provide a gripping force on clothing material sufficient enough to substantially prevent relative movement between the temple bars and the clothing material.


A lens axis alignment device is provided for use in a lens-surfacing machine. The device has a lens carrier for a blocked lens and means for locking the blocked lens on the carrier. The lens axis alignment means is provided to align the blocked lens axis with respect to the carrier. The invention enables optical retail stores to provide 1-hour service for multifocal lenses using only one machine at the retail point.

Speedy service is becoming the norm for many consumer products such as spectacles or optical lenses. To meet this demand, optical retail stores glaze and fit stock lenses into frames and advertise a 1-hour service. But the provision of multifocal or varifocal lenses presents difficulties. Approximately 80% of multifocal patients need a cylinder correction, and until recently there was no alternative to sending the prescription away to an optical laboratory for processing. A quick look at the existing options for speedy service in retail practice lens-making reveals the need for a high level of investment, either in cash or in experienced personnel, to be sure of quality lenses in the short time cycles desirable.
One solution has been for an optical practice to buy thin lens wafers and then assemble two such wafers together to provide a bi-focal lens according to the prescription. The wafers are bonded with UV sensitive adhesive and cured. Although relatively fast, this method ties the practice to a narrow range of lens forms obtained only from the original supplier. Another solution is to buy equipment which permits cast lenses to be made as they would be cast in a factory. However, curing such lenses takes at least three hours by water or overnight by air, and an inevitable proportion of rejects will leave some customers still disappointed. Moreover, the equipment requires an investment of about $70,000.
The most popular option at the present time, due to the sophisticated machine tools produced by several specialist optical engineering companies and a pool of skilled labor available from existing optical wholesalers, is to use traditional lens-surfacing machines and methods. However, a thousand square feet of floor space, ample power points, water supplies with good drainage and ideally three staff members makes for a major project. An investment of nearly $100,000 is called for by this option.

Lens axis alignment device for use in a lens-surfacing machine