An oligomer of alpha olefin is produced in a three step process comprising 1) oligomerization to a vinylidene, 2) hydroformylation to a primary alcohol, and 3) dimerization of the alcohol. The final product can be hydrogenated to form a branched alkane with improved lubricating oil properties.

Poly Alpha Olefins (PAOs) are known and used as lubricating oils or in lubricating oil formulations. PAOs are typically dimers, trimers and tetramers of 1-octene, 1-decene and/or 1-dodecene and are made by a two-stage process such as that described in U.S. Pat. No. 4,045,507. Alpha olefins can also be oligomerized by metallocene catalyst, as described in U.S. Pat. No. 4,658,078 and U.S. Pat. No. 7,129,197. Other synthetic lubricating oils are esters or alkylated naphthalenes. Highly refined fractions of crude oil are also used as lubricating oils.
Each of these classes of lubricating oil have physical and chemical properties that make them useful as a lubricating oil. Nonetheless, there is still a need for lubricating oils with improved properties. This is particularly the case as the demands on lubricating oils increase.


A virtual media tray causes a print device to perform one or more operations in response to a request to print a document. The operations may include storing, emailing, or faxing a copy of the document to another location. The operations may also include adding text in the form of a header, footer, or watermark when the document is printed. An operation associated with a virtual print tray may also have an associated condition such that the operation is performed when the associated condition is satisfied.

Many business environments establish policies and/or procedures associated with documents generated within a company. Such policies may include definitions of standard text or watermarks that are printed on documents, policies that require copies of printed documents be stored in a document management system, or policies that require copies of documents be emailed or faxed to management or other individuals.
Networked printers provide a centralized print device that is available to users of any number of computer systems that are connected to the network. Many printers also have multiple print media trays, which allow users to print documents to different media (e.g., legal or letter size paper, colored paper, transparencies, etc.). Networked printers may also be configured to automatically implement document policies and/or procedures to be applied to documents that are sent to the printer.

Hewlett-Packard Development Company, L.P.


A new cultivar of Streptocarpus plant named ‘Spirit’ that is characterized by a large quantity of violet-blue flowers with a darker purple center venation.

The present invention relates to a new and distinct cultivar of Streptocarpus plant botanically known as Streptocarpus and hereinafter referred to by the cultivar name 'Spirit'.
'Spirit' was discovered by the inventor in March of 2005 in Vaihingen/Enz, Germany. 'Spirit' was discovered as a naturally occurring whole plant mutation in a bed of Streptocarpus 'Targa' (not patented) within a glass greenhouse.
Asexual reproduction of the new cultivar 'Spirit' first occurred by leaf cuttings in July of 2005 in Vaihingen/Enz, Germany. Since that time, under careful observation, the unique characteristics of the new cultivar have been uniform, stable and reproduced true to type in successive generations of asexual reproduction.


An intermediary system operates as an intermediary between content servers and user devices, and provides services for improving page load times as seen by end users. One such service involves converting a retrieved content page (e.g., web page) into a number of encoded layers that can be decoded and rendered by the user device. The intermediary system determines a suitable encoding technique for each of the layers. The intermediary system sends the encoded layers to a browser component running on the user device for rendering by the GPU.

When a user requests a web page or other content page via a browser, the user typically experiences a noticeable delay before the page is fully or even partially displayed. Various factors can contribute to this delay. These factors include, for example, (1) the speed of the wireless or wired connection between the user's device and the Internet, (2) the location of, and load on, the origin server that hosts the page, (3) the size of the page, including any embedded graphics, (4) whether, and the extent to which, the page includes embedded objects that need to be separately retrieved (possibly from different domains) once the page's HTML has been loaded, (5) the complexity of the page's coding, including any scripts, and (6) the processing power of the user's device. When the delay is significant (e.g., several seconds or more), the task of browsing can be frustrating for users.
Various methods exist for reducing the delay experienced by users. Some methods include the use of caching proxy servers, which store recently-retrieved versions of content and provide the content to users faster than origin servers may be able to do so. For example, a caching proxy may be located closer (in either a geographic or networking sense) to a client device, or the caching proxy may have a faster network connection to the client device. Origin servers may also deploy certain content onto content delivery network ("CDN") servers. Client devices requesting the content may be directed to the closest CDN server or to a CDN server that can otherwise provide the requested content faster than the origin server. Other methods of reducing the delay experienced by users include the use of proxy servers or other intermediary systems that compress or re-format content. Such processed content may be transferred to client devices faster, or may require less processing by the client devices to render the content.

Split browser architecture capable of determining whether to combine or split content layers based on the encoding of content within each layer


A seeding machine having at least one tool bar, a plurality of row units and a processing circuit. Each of the plurality of row units are connected to the toolbar. Each of the row units have a seed metering device, a seed placement device and a seed sensor. The seed metering device includes a seed disk providing a metering action to a plurality of seeds. The seed placement device receives the seeds from the seed metering device. The seed sensor is positioned to detect the passage of seeds through either the metering device or the seed placement device. The seed sensor producing a signal indicative of the passage of the seeds. The processing circuit is receptive of the signal from each of the seed sensors of each of the plurality of row units. The processing circuit determines a seed placement parameter dependent upon the signal, the processing circuit alters the metering action of the seeds dependent on the seed placement parameter.

An agricultural seeding machine, such as a row crop planter or grain drill, places the seed at a desired depth within a plurality of parallel seed trenches formed in soil. In the case of a row crop planter, a plurality of row crop units are typically ground driven using wheels, shafts, sprockets, transfer cases, chains and the like. Each row crop unit has a frame, which is movably coupled with a tool bar. The frame may carry a main seed hopper, herbicide hopper and insecticide hopper. If the granular herbicide and insecticide are used, the metering mechanisms associated therewith for the dispensing of the granular product into the seed trench are relatively simple. On the other hand, mechanisms necessary to properly meter seeds at a predetermined rate and to place the seeds at a predetermined relative locations and depth within the seed trench are relatively complicated.
The mechanisms associated with metering and placing of the seeds generally can be divided into a seed metering system and a seed placement system, which are in communication with each other. The seed metering system receives the seeds in a bulk manner from a seed hopper carried by the frame. Different types of seed metering systems can be used such as seed plates, finger plates and seed disk. In the case of a seed disk metering system, a seed disk is formed with a plurality of seed cells spaced about the periphery thereof. Seeds are moved into the seed cells with one or more seeds in each seed cell depending upon the size and configuration of the seed cell. A vacuum or positive pressure airflow may be used in conjunction with the seed disk to assist in movement and retention of the seeds in the seed cells. The seeds are singulated and discharged at a predetermined rate to the seed placement system.
The seed placement system may be categorized as a gravity drop system or a power drop system. In the case of a gravity drop system, a seed tube has an inlet end, which is positioned below the seed metering system. The singulated seeds from the seed metering system merely drop into the seed tube and fall by way of gravitational force from a discharge end thereof into the seed trench. The seed tube may be curved in a rearward manner to assist in directing the seed into the seed trench
A seed placement system of the power drop variety generally can be classified as a seed conveyor belt drop, rotary valve drop, chain drop or air drop. These types of seed placement systems provide somewhat consistent placement of the seeds along a predetermined path at a desired spacing.
Certain seed types, such as flat corn seed with insecticide or other treatments thereon are difficult for vacuum meters to singulate. Poor singulation of difficult seed types is characterized by doubles, skips and bunches of seed carried by the disk. Doubles and skips refer to multiple seeds and no seed, respectively, in each seed cell. Bunches are multiple seeds carried by the seed pool accelerators, which protrude from the surface of the seed disk. These seed types generally are best planted with a flat seed disk in combination with a doubles eliminator.
What is needed in the art is an agricultural seeding machine having an accurate positive seed spacing monitor and an efficient adjustment of a seed metering system.


The present invention provides a resin composition containing a filler poor in affinity for fluororesins as uniformly dispersed therein and a method of producing such resin composition and, further, a resin composition containing, as fillers, a nucleating agent for foaming and suited for producing foamed moldings with fine foam cells uniformly distributed therein and a method of producing such resin composition as well as a foamed molding formed from either of such resin compositions. The present invention is related to a resin composition comprising a fluororesin (A) and a filler (X) low in affinity for said fluororesin (A), wherein the filler (X) has a d99 value of not more than 15 μm.

The effects of addition of a filler to fluororesins are greatly influenced by the morphology, particle diameter and chemical properties of filler particles. Generally, an improvement in filler dispersibility produces beneficial effects on mechanical strength characteristics, for example tensile strength, rigidity, and hardness. Further, an improvement in filler dispersibility is highly effective in producing improvements in thermal conductivity, chemical resistance, and workability, for instance.
For improving the dispersibility of a filler having low affinity for fluororesins, the filler is surface-modified, for example, by treatment with a silane coupling agent or by fluorination treatment to provide it with affinity for fluororesins.
However, such filler surface modification requires the use of a complicated equipment and, in addition, unfavorably results in an increase in filler production cost. Therefore, a method of uniformly dispersing, in fluororesins, a filler having low affinity for fluororesins without surface modification is demanded.
For example, conductive wires to be used for transmitting electronic signals are required to be isolated so that accurate transmission may be secured. Such isolation is realized, for example, by melting a resin and extruding it around a conductive wire to form a covering material. Judiciously used as such resin are fluororesins because of their being low in permittivity, lightweight and excellent in heat resistance, flame resistance and smokelessness, among others.
For attaining improvements in electrical characteristics, the covering material for conductive wires is desired to have a reduced permittivity. For reducing permittivity, it is effective to mold the covering material in a foamed moldings. Foamed moldings made from a resin are generally produced by foam molding, namely molding a molten resin while allowing a gas to be present therein. For obtaining foamed moldings uniform in shape and characteristics, it is desirable that the foam cells in the foamed moldings are fine and uniformly distributed.
For the purpose of rendering foam cells fine and uniformly distributed, there is a method known which comprises causing a nucleating agent for foaming to be present in resins so that the agent may form the origins for foam cell formation in the step of foam molding. Preferably used as the nucleating agent for foaming to be added to such resins as fluororesins is boron nitride (BN) since this is thermally stable, chemically inert and low in toxicity and has favorable electrical properties, for example it causes only slight changes in permittivity due to addition thereof.
As regards the technology of obtaining foamed moldings by incorporating BN as a nucleating agent for foaming in resins such as fluororesins, there are the following disclosures about BN, among others:
Japanese Kokai Publication Hei-8-12796 discloses that the combination of BN and zeolite is optimal among the combinations of ceramics or starting materials thereof with zeolite as nucleating agents for foaming.
Japanese Kokai Publication Sho-63-24503 and Japanese Kokai Publication Sho-63-110508 disclose methods which use BN as a nucleating agent for foaming.
Japanese Kokai Publication Sho-59-11340 discloses a method comprising adding BN having a surface area of 5 to 10 m2/g as a nucleating agent for foaming.
Japanese Kokoku Publication Hei-6-89166, U.S. Pat. No. 4,877,815 and U.S. Pat. No. 5,023,279 disclose the combined use of BN having a surface area of 8.6 m2/g with a sulfonic acid, a phosphonic acid or a salt thereof.
Japanese Kokoku Publication Hei-07-121999 and Japanese Kokai Publication (U.S. Pat. No. 4,764,538) disclose the combined use of BN having a surface area of about 8 m2/g with a thermally stable inorganic salt composed of a metal cation and a polyatomic anion and satisfying a certain relation, for example sodium tetraborate.
U.S. Pat. No. 3,072,583 discloses that the use of BN having an average particle diameter smaller than 10 μm is preferred in forming foamed fluororesin moldings and that the resin and BN is ground in an appropriate mill.
Japanese Kokai Publication Hei-10-195216 discloses a method which comprises mixing up a resin powder capable of foaming by decarboxylation, BN and a metal salt to give a blend, granulating the blend with a compactor and then with a hammer mill or a like grinder to give a powder, or pelletizing the blend with a pellet mill, and the pellets to an extruder and, according to the disclosure, the use of a Henschel mixer (product of Purnell International) is preferred in blending.
Japanese Kokai Publication Hei-10-45931 discloses a foaming method comprising using a processable fluorine-containing polymeric substance and BN in combination with a sulfonic acid or phosphonic acid or an acid salt thereof and/or a polyatomic-anion-containing inorganic salt, said BN having a form of crystals grown to a final size with an average particle size of not larger than 12 μm. It is described that this BN is prepared not by mechanical grinding of crushing individual crystals but by deagglomeration in case of occurrence of agglomeration of individual grown crystallites.
However, in any of these methods of obtaining foamed moldings by incorporating a nucleating agent in resins, there is no attention paid to the particle size distribution of the nucleating agent material or, further, to the particle size distribution of the nucleating agent in resin compositions.
These prior art technologies are not fully satisfactory in the existing circumstances in which a covering material further improved in electrical characteristics is demanded as a result of the increase in the volume of information to be transmitted at a time as resulting from the increase in the speed of communication owing to the recent advances in information-related technologies.

Resin composition, process for production thereof, and foam-insulated electric wire


A physical layer device for interfacing with multiple computing devices includes a digital core and first and second analog front ends. The digital core is operative to perform one or more functions of the physical layer device. Each of the first and second analog front ends is operative to perform signal conversion between a digital domain and an analog domain. The physical layer device further includes a digital switching circuit coupled to the digital core and to the first and second analog front ends. The digital switching circuit is operative to electrically connect the digital core to the first analog front end or the second analog front end as a function of a control signal applied to the digital switching circuit.

In modern computer networking applications, particularly those involving portable computing devices, a gigabit Ethernet (GE) port (e.g., RJ-45 connector) is typically provided on a portable computer (e.g., laptop computer, etc.), for portable use, and on a docking station adapted to receive the portable computer, for desktop/home base use. In order to provide a network connection to the portable computer when used in both docked and undocked states from a single GE physical layer (PHY) port, an analog local area network (LAN) switch is typically employed. In this arrangement, one side of the LAN switch is connected to an analog output of the GE PHY port. The other side of the LAN switch provides two sets of analog output pins (e.g., media dependent interface (MDI) pins) for connection to the GE port connectors (e.g., RJ-45) associated with the portable computer and the docking station, respectively. Although two separate GE PHY ports can be alternatively utilized, such approach would be significantly more expensive and thus undesirable.
The use of an analog LAN switch to provide multiple GE port connections has a number of disadvantages that become exacerbated as integrated circuit (IC) process technology scales to smaller geometries and lower voltages. Specifically, the LAN switch adds significant resistance and capacitance to a network signal path (e.g., typically about 8 to 12 ohms per pair of MDI pins). This results in substantial attenuation of a signal conveyed through the signal path from the pins of the single PHY port to the GE port connectors. This problem is particularly difficult for the docking station GE port connector as there are, by necessity, long printed circuit board (PCB) traces used for conveying networking signals, and other signals, as they are routed through the docking station connector.
With each advance in IC process technology, transistors sizes shrink and operating voltages decrease. This results in significant savings in both IC area and overall power consumption, thereby resulting in lower cost. However, with smaller transistors it also becomes more difficult to generate high input/output (I/O) voltages often required for many standard networking protocols. I/O voltages have dropped from about 5 volts to about 3.3 volts, and are now trending towards 2.5 volts and lower. For instance, 10 Base-T MDI signal levels are typically about 2.5 volts.
IC integration is heavily driven by process technology migration, which allows a far greater number of digital gates to be integrated at a very low cost. However, to take full advantage of process advances, analog IO functions must also be integrated (e.g., GE PHY function). The use of an analog LAN switch for providing dual GE port connectivity, and the additional parasitic impedances introduced by the analog LAN switch, make it more difficult to take full advantage of process technology migration and corresponding cost savings.

Physical layer interface for computing devices


An image data compression device includes a quantization section, a FIFO buffer section, an encoded data generation section, and a rate control section. The quantization section quantizes image data by a quantization step which changes based on a quantization parameter. The FIFO buffer section stores the quantized data for at least N frames (N is an integer greater than one) from the quantization section. The encoded data generation section generates encoded data by encoding the quantized data read asynchronously from writing into the FIFO buffer section. The rate control section calculates the quantization parameter by using an average data size of encoded data for previous N frames. The quantization parameter is calculated to be equal to or less than an upper threshold of the quantization parameter which is set or canceled based on the number of assignable bits which can be assigned to the compression processing and the number of remaining frames.

The present invention relates to an image data compression device and an encoder.
Moving Picture Experts Group Phase 4 (MPEG-4) has been standardized as a general-purpose coding method for multimedia information such as image data of a still image or a moving image and sound data. A recent portable instrument implements encoding and decoding of image data conforming to the MPEG-4 standard, and can perform moving image reproduction and transmission/reception through a network.
In the MPEG-4 standard, compressed data obtained by encoding image data of a moving image must be generated at a constant rate. However, when compressing image data of a moving image, the compression efficiency changes to a large extent depending on the type of image data. MPEG-4 Visual Part (Recommendation ISO/IEC 14496-2: 1999 (E) Annex L) describes a rate control for generating compressed data at a constant rate by controlling the amount of code to be generated so that such a change is limited within a predetermined range.
When performing MPEG-4 encode (compression) processing, a series of processing may be entirely performed by hardware. However, since this increases the circuit scale, it is difficult to achieve a reduction of size when integrating circuits in an IC (semiconductor device or integrated circuit). In particular, a portable instrument such as a portable telephone cannot satisfy a demand for a reduction of the size of the instrument.
A series of encode processing may be entirely performed by using software. However, this increases the load imposed on a central processing unit (CPU) which processes the software. Therefore, the time necessary for the CPU to perform another processing is limited, whereby the performance of an instrument provided with the CPU is decreased. Moreover, the processing time of the CPU is increased, whereby power consumption is increased. In particular, a portable instrument such as a portable telephone cannot satisfy a demand for a reduction of power consumption in order to maintain battery life.
Therefore, a series of encode processing may be allocated between hardware and software. However, as a result of studies conducted by the inventors of the present invention, it was found that the rate control disclosed in MPEG-4 Visual Part (Recommendation ISO/IEC 14496-2: 1999 (E) Annex L) cannot be performed when optimizing the allocation of a series of encode processing between hardware and software. Therefore, optimization of allocation of image data compression processing between hardware and software and generation of compressed data at a constant rate cannot be achieved together.
According to the rate control described in MPEG-4 Visual Part (Recommendation ISO/IEC 14496-2: 1999 (E) Annex L), even if the generation rate of compressed data can be controlled, block noise is generally displayed in the image generated by decompressing the compressed data, whereby the display quality may deteriorate.
On the other hand, the amount of compressed data is increased in order to prevent deterioration of display quality, whereby a desired bit rate may not be maintained. When performing encode processing in order to maintain a desired bit rate, the maximum encoding size which can be generated as a result of encoding is determined by giving the encoding time. In this case, when a large number of bits are used in the first half of the encode processing, the bit rate likely overshoots, whereby it becomes difficult to maintain a desired bit rate.

Image data compression device and encoder


Methods for the real-time, reversible compression of high dynamic range videos, allowing high dynamic range videos to be broadcast through standard dynamic range channels. The methods include streaming pixel values from at least one image sensor through a pipeline on a processor. The pipeline includes an HDR function that combines the streaming pixel values in real-time into an HDR stream and a transfer function that converts the HDR stream to an SDR video stream. The method further includes transmitting the SDR video stream to a receiver in real time for display as a video.

Humans can see brightness variations over a dynamic range of about 10,000:1 simultaneously within a scene. Some cameras are able to capture images over that dynamic range and preserve the dynamic range by encoding the images digitally by storing pixel brightness values 14 bits per color. Human visual perception has a non-linear relationship to brightness, and brightness is often encoded digitally using a non-linear power law known as a gamma function.
Early research and technology such as cathode ray tubes suggested that video signals should be digitized using a gamma function using 8 bits per pixel for brightness. Accordingly, much contemporary digital video for consumer equipment and computer graphics uses 8 bit encoding. Existing television, cable, and satellite channels typically operate with 8 bit signals defining the standard dynamic range. Thus, while some modern cameras capture images at a higher dynamic range, video is typically broadcast and displayed at 8 bit standard dynamic range.


In the method of programming a phase change memory cell, having a lower resistive state and a higher resistive state, to the lower resistive state, the memory cell is heated to first temperature. Subsequently, the memory cell is heated to second temperature, which is greater than the first temperature.

Solid state memory devices that use a structural phase-change material as the data storage mechanism (referred to here simply as 'phase-change memories') offer significant advantages in both cost and performance over conventional charge storage based memories. The phase-change memory is made of an array of constituent cells where each cell has some structural phase change material to store the cell's data. This material may be, for instance, a chalcogenide alloy that exhibits a reversible structural phase change from amorphous to crystalline. A small volume of the chalcogenide alloy is integrated into a circuit that allows the cell to act as a fast switching programmable resistor. This programmable resistor can exhibit greater than 40 times dynamic range of resistivity between a relatively crystalline phase (low resistivity) and a relatively amorphous phase (high resistivity). The data stored in the cell is read by measuring the cell's resistance. The chalcogenide alloy cell is also non-volatile.
FIGS. 1A and 1B illustrate an example of a phase change memory cell. As shown, the memory cell 10 includes a phase change material 12 disposed between a bottom electrode 14 and a top electrode 16. A bottom electrode contact 18 provides for electrical contact between the bottom electrode 14 and the phase change material 12. A transistor 20 selectively supplies a current to the memory cell 10 to selectively change the state of the phase change material. FIG. 1A illustrates the state of the phase change material 12 when reset (i.e., when in the amorphous state), and FIG. 1B illustrates the state of the phase change material 12 when set (i.e., in the crystalline state). As will be appreciated from FIG. 1A, the phase change material 12 is not completely changed to the amorphous state when reset, and the phase change material 12 may not be complete changed to the crystalline state when set.
A conventional technique for programming a phase-change memory cell is to apply a rectangular pulse of current (having a constant magnitude throughout the pulse) to the cell 10, at a voltage greater than a switching threshold for the phase change material 12, which leaves the cell 10 in the reset state (the phase change material 12 is relatively amorphous and has high resistivity). To change the state to a set state (the phase change material 12 is relatively crystalline and has low resistivity), a rectangular lower current pulse, also at a voltage greater than the switching threshold, is applied to the memory cell 10. The reset pulse has a higher magnitude of current than the set pulse so that the temperature of the phase change material 12 is raised to an amorphizing temperature, before the phase change material 12 is rapidly cooled down or quenched by the very sharp decrease in current at the trailing edge of the reset pulse; thereby leaving the phase change material 12 in the amorphous phase. To change into the crystalline phase, the phase change material 12 can be heated to a temperature, which is lower than the amorphizing temperature, using a rectangular current pulse of smaller magnitude, and then rapidly cooled down again, this time leaving the phase change material 12 in the crystalline (low resistance) phase. Here, the set pulse is considerably longer than the reset pulse.
It is also known to change the phase change material 12 into the crystalline phase by heating the phase change material up to the amorphizing temperature and slowly reducing the applied current to reduce the temperature of the phase change material 12. As the temperature of the phase change material 12 slowly decreases, the phase change material 12 crystallizes. This method of setting the memory cell also requires a significant amount of time.

Method and driver for programming phase change memory cell


An electrosurgical cutting device comprises an instrument body, and first and second cutting blades, at least one of which is pivotally mounted on the body to execute a scissor action with respect to the other blade. Electrical supply conductors associated with the body supply an electrosurgical voltage to the first and second blades. The first blade is a composite blade comprising a conductive outer electrode, an inner conductive layer, sandwiched between the outer electrode and the inner layer, an insulating layer. The supply conductors are connected respectively to the outer electrode and to the inner layer.

This invention relates to an electrosurgical cutting device having a pair of blades which are mounted so as to execute a scissor action whereby, when an electrosurgical voltage is applied, the device acts simultaneously to desiccate and shear living tissue.
It is known to perform surgical cutting using a scissor instrument having a pair of blades mounted at the end of an elongate shaft, each blade being rotatable about an axis which is transverse to the shaft in response to movement of a control rod extending between the blades and a handpiece at the other end of the shaft. The two blades are electrically insulated from each other and have ceramic coatings on their opposing surfaces so that they can be connected to a source of bipolar electrosurgical power without electrical short-circuiting. Tissue trapped between the blades is subjected to passage of electrosurgical current distally of the intersection of the cutting edges of the blades so as to desiccate the tissue prior to mechanical parting as the blades are closed together.


In a TDMA system whereby the TDMA system comprises a plurality of subscriber units and a plurality of base radios, a method and system for providing access to a channel for voice transmissions where the first subscriber unit determines whether it is provisioned for polite access to the channel. In addition, the first subscriber unit is characterized by a first color code and a first talkgroup ID. The first subscriber unit also examines the voice transmissions on the channel for voice transmissions that are from a second subscriber unit with a second color code and a second talkgroup ID. If the first color code and the second color code match and if the first talkgroup ID and the second talkgroup match, then the first subscriber unit is allowed access to the channel for voice transmissions even though the channel is being used for voice transmissions by the second subscriber unit.

A wireless communications system may generally comprise a set of "subscriber units," typically subscriber units are the endpoints of a communication path, and a set of "base radios," typically stationary and the intermediaries by which a communication path to a subscriber unit (SU) may be established or maintained. One such type of system is a time division multiple access (TDMA) communication system where the radio medium is divided into time slots to carry the communications of the system. Because the radio medium is a shared medium, there is a need for managing access to the radio medium and allowing the SUs to utilize the radio medium for voice communications.
Specifically, for a SU to make a transmission, the SU must first activate a base radio (BR) and acquire synchronization. Once synchronization is obtained, the SU requests that a call be setup and then transmits on the radio medium. Because activating a BR and synchronization are necessary, extra time is required to place a call. Thus, it is desirable to avoid these procedures to decrease the amount of time it takes to place a call. Further, there are cases where certain SUs need preferential access to the radio medium and need to be given access to the radio medium to transmit during the context of an active call.
Thus, there exists a need for providing access to a channel for voice communications.
It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements are exaggerated relative to each other. Further, where considered appropriate, reference numerals have been repeated among the figures to indicate identical elements.

Method for allowing a subscriber unit to access a channel for voice transmissions


In the preparation of a film by melt-extrusion process of thermoplastic polyimide, static charge is applied to a molten film, primary cooling is carried out by adhering the film to a cooling roller having a surface temperature in the range of from the glass transition temperature of said polyimide -50.degree. C. to the glass transition temperature -15.degree. C., the film is successively cooled to 60.degree. C. and less without bringing the film into contact with rollers, and is taken up under tension to give a polyimide film.

1. Field of the Invention
The present invention relates to a process for the preparation of a film essentially consisting of thermoplastic polyimide. More particularly, the invention relates to a preparation process of a thermoplastic polyimide film comprising cooling a molten film under specific conditions and taking-up the film under tension in an extrusion process.
2. Description of the Prior Art
Industrial machinery in various fields has recently been directed toward miniaturization and weight reduction. The parts for constituting the machinery are also required to have reliability over prolonged periods in the areas of heat resistance, mechanical properties and dimensional stability. Plastic films used for the above industrial machinery are also required to have the above performance.
At present, film materials having the highest heat-resistance designed to meet the above requirement are various polyimide films such as Upilex.TM. (a product of Ube Industries Co. Ltd.) and Kapton.TM. (a product of E. I. Du Pont De Nemours & Co.). Since hot molding of the above polyimide is difficult, films are prepared by a so-called solution casting method where a polyamic acid precursor solution is cast and heat-treated to form a polyimide film.
On the other hand, hot-moldable polyimides such as polyetherimide and polyimide which are disclosed in Japanese Patent Laid-Open Publication SHO No. 62-205124(1987) have been developed. Using the thermoplastic polyimide, films can be prepared by a so-called extrusion process where polyimide is heat-melted in an extruder and the molten polyimide delivered from a die is cooled solidified by contact with a cooling roller.
In order to obtain high quality film by an extrusion process, adhesion of the molten film to the cooling roller is important in the cooling and solidifying step of the extruded molten material from the die.
The methods for improving adhesion include:
(1) A method for blowing air out of a slit nozzle (air knife method).
(2) A method for mechanically pressing the molten film with a rubber roller at the contact point of the molten film with the cooling roller (rubber roller method).
(3) A method for applying static charge to the molten film and electrostatically influencing the film into close contact with the cooling roller (static charge application method).
However, in the extrusion process of the above thermoplastic polyimide, the air knife method has a drawback in that it is difficult to evenly provide the whole film with sufficient pressure to uniformly adhere the molten film to the cooling roller. Consequently, cooling becomes non-uniform and has caused problems such as defects in flatness and spot variation in the thickness of the solidified film.
As to the rubber roller method, for example, Japanese Patent Laid-Open Publication SHO No. 62-290515(1987) discloses a method for assuming the glass transition point (Tg) of the resin to be processed as the reference temperature, setting the surface temperature of the cooling roller in the range of (Tg)-50.degree. to (Tg)-10.degree. C., and nipping the film with a rubber roller having a surface hardness of 70 degrees or less under a specific range of linear pressure. However, the rubber roller deforms during use even though the roundness of the roller is extremely accurate in the initial stage, which leads to irregularity in linear pressure of the rubber roller and has caused problems such as spot variation in the thickness of the film.
As to the static charge application method, for example, Japanese Patent Publication HEI No. 1-53620(1989) describes a method for preparing an amorphous film having low optical strain by applying static charge to a molten film, uniformly adhering the film to a cooling roller having a temperature of the glass transition point (Tg)-10.degree. C. and transmitting the film without tension by using a second roller having a slightly lower peripheral speed then that of the cooling roller. The static charge application method provides good adhesion of the film to the cooling roller. In the method, however, it is difficult to maintain flatness of the film and to prevent generation of creases because electrostatically adhered film is released from the cooling roller without tension.
Further, the film obtained has been defective in that very small flaws are observed over the whole surface of the film.


The invention provides a wire bond bonding a wire to a connection pad of an electronic device, and a method of forming the wire bond. A first stitch bond is formed on the connection pad, and a second stitch bond is next formed on the connection pad that is contiguous with the first stitch bond.

During semiconductor assembly processes, there is sometimes a necessity to make electrical connections between connection pads of electronic devices. The electrical connections can be formed by using conductive wires to establish linkages between the connection pads. The most widely used wire materials are Gold (Au) and Aluminum (Al), but Silver (Ag) and Copper (Cu) are also used. The connection pads may comprise metallized bond sites on a semiconductor chip or on interconnection substrates. A wire bond secures the wire to the connection pad in order to ensure that the electrical connection is secure and the wire is not easily dislodged from the connection pad.
There is typically a first bonding position where a first wire bond is made and a second bonding position where a second wire bond is made. Generally, the wire bonding process involves feeding a conductive wire through a capillary of a wire bonding device and using the capillary to manipulate and bond the wire.
A typical wire bonding process is hereinafter described. The capillary is first located over a first bonding position. A clamp controlling the wire opens and wire extends out of the capillary. An electro flame-off spark is generated to create a free air ball at a tail of the wire and the capillary moves towards the first bonding position with the free air ball. The free air ball is placed onto the first bonding position, and ultrasonic energy and pressure is applied onto the ball to create a first wire bond between the wire and the connection pad at the first bonding position.
After the first bond is made, the capillary moves away from the first bonding position and wire is extended by the capillary as the capillary is moved towards the second bonding position in order to form a wire loop. The capillary moves to the second bonding position and presses the wire onto second bonding position. Ultrasonic energy and pressure is applied onto the wire and stitch bonding is performed to the wire at the capillary tip, thereby stitching the wire to the connection pad at the second bonding position. After the second bond is made, the capillary moves away from the connection pad at which point the wire has been bonded between two points. As the capillary moves away from the second bonding position, the clamp is closed such that the wire is pulled and severed from the wire bond made at the second bonding position.
It may be difficult to form a sufficiently strong stitch bond at the second bonding position for certain types of connection pads using conventional stitch bonding. The stitch pull tolerance of the wire bond, which is the amount of pulling force the wire bond can withstand before dislocation, is usually small and the stitch quality is not good, especially when conventional stitch bonding is utilized for ultra-fine pitch wire bonding. If the bond is not strong, the wire may be easily pulled away from the connection pad, leading to unreliability of the electrical connection made. In order to increase the bond strength, special bonding techniques were developed, such as the so-called ball bond on stitching ("BBOS") or ball stitching on bond ("BSOB").
BBOS involves placing a ball bump on top of the stitch bond already made at the second bonding position. The process is described in U.S. Pat. No. 5,960,262 entitled "Stitch Bond Enhancement for Hard-to-Bond Materials". On the other hand, BSOB involves first forming a ball bump at the second bonding position, before placing a stitch bond on top of the ball bump. This process is described in U.S. Pat. No. 5,328,079 entitled "Method and Arrangement for Bond Wire Connecting Together Certain Integrated Circuit Components". Both these methods assist in increasing a contact area between a wire bond and a connection pad so as to increase their degree of intermetallization.
However, the said BBOS and BSOB techniques present some problems. Although they serve to improve the strength of the second stitch, they may cause sway wire or snake wire problems due to the construction of the bonds. Sway wire refers to a tendency for the wire loop to deviate from a straight line passing through the connection pads at the first and second bonding positions and therefore threaten to contact adjacent wire loops, which might cause a short-circuit. This is sometimes due to the fact that the ball bump does not sufficiently anchor the wire to prevent sideways motion. Snake wire refers to a tendency of the wire in the capillary to recoil after a wire is broken at the second bond position when forming a ball bump, thus affecting the linearity of the wire for the next bond. There is at present no effective way to solve these problems with the BBOS and BSOB techniques. Furthermore, the BBOS and BSOB techniques require a longer bonding cycle time because of the need to form a ball bump in addition to forming a stitch bond.

Method of fabricating a wire bond with multiple stitch bonds


The present invention is a signaling device for indicating passage of a pig through a pipeline. The device attaches to the pipeline by means of a nipple welded to the pipeline. As a pig travels past the device, an actuator of the device which hangs down into the pipeline is pushed upward by the pig. The actuator causes a spring biased plunger located within the device to move upward, causing a polar magnet attached to the plunger's upper end to approach a rotatable magnetic indicator ball. The ball is colored black on an upper half which is initially visible through a clear dust cover provided on the device and is colored yellow on a lower half. The upper half of the ball is of opposite polarity and the lower half is of like polarity to the polar magnet. As the polar magnet approaches the rotatable magnetic ball, the yellow half of the magnetic indicator ball is repelled by the like polarity of the polar magnet, causing the magnetic indicator ball to rotate 180 degrees so that the yellow half is now visible through the dust cover. After the pig has passed, the plunger springs back to its original lower position and the ball can be reset to its original position by means of a reset lever attached to the ball. An alternate embodiment replaces the magnetic indicator ball with a proximity switch which is activated when the polar magnet approaches the proximity switch as the plunger moves upward.

1. Field of the Invention
The present invention relates to a device for detecting and signaling the passage of a pig past a point in a pipeline. More specifically, the present invention relates to a device employing a magnetic field to initiate either a visual or an electronic signal to indicate passage of the pig.
2. Description Of The Related Art
In the pipeline industry it is common practice to utilize a movable plug or a pig (hereinafter referred to as a pig) within a pipeline either to travel between and separate different products as they flow consecutively through a single pipeline or to travel through the pipeline in order to service it by cleaning it, mapping it, etc. Whenever a pig is being used, it is necessary to be able to detect its location. One way this is done is to utilize a device which remains stationary relative to the pipeline and is provided with means for detecting and signaling passage of the pig past the device.
Previous devices for detecting and signaling passage of a pig can be categorized as one of two general types. The first type, as exemplified by U.S. Pat. No. 3,109,410 issued on Nov. 5, 1963 to inventor Burton Ver Nooy, employs a trigger mechanism internally disposed within the pipeline which is physically tripped by passage of a pig. The physical movement of the trigger is transmitted by a variety of gears or other types of mechanical means through a sealing mechanism in an enclosure of the device to a signaling device located exterior to the enclosure.
One of the main problems with this type of device is that leakage occurs around the movable element which connects the internal trigger to the external signaling device. This type of device can be problematic because of its sealing method when used on high pressure pipelines and when used on pipelines transporting materials corrosive to the materials used in the sealing mechanism.
The second type of device for detecting and signaling passage of a pig is represented by U.S. Pat. No. 4,638,278 issued on Jan. 20, 1987 to inventor Mark E. Bullock. This second type of device employs a specially designed pig, usually one to which magnets have been attached. This special pig is magnetically detected by a sensing unit located external to the pipeline. The sensing unit normally employs a magnetically triggered switch which can be used to operate a signaling device.
One of the main problems with this type of device is that the pig must be constructed of a magnetically detectable material or must be retrofitted with magnetically detectable material, such as magnets, in order for the sensing unit to detect its passage. Use of magnetically detectable material in a pig adds to the pig's weight and the magnetically detectable material can be chemically degraded by corrosive materials contained within the pipeline.
The present invention addresses these problems by providing a device which combines the reliability of mechanical triggering with the non-intrusiveness of magnetic sensing. Specifically, the present invention utilizes an enclosed and sealed trigger mechanism provided with a polar magnet on its upper end and provided with an actuator on its lower end which extends down into the pipeline. A passing pig engages the actuator, causing the trigger mechanism and the attached polar magnet to move upward where a magnetic field associated with the polar magnet passes through a sealed enclosure housing the trigger mechanism and can either activate a visual signal device or, optionally, can activate a proximity switch.

Bidirectional pipeline pig signaling device


The present invention relates to a light valve image projector with a disposition for improving the contrast of an optical image projected on a screen by that projector. The projector comprises at least one illumination system, at least one field lens, at least one set consisting of a polarizer, an LCD and an analyzer and at least a projection lens, and presents at least one optical axis which includes an angle .alpha. with the optical axis of the projection lenses. The invention consists in positioning the analyzer so that it includes an angle larger than .alpha. with the LCD, at least for the light rays that pass through the contrast limited area of the LCD. The invention consists furthermore in placing the polarizer so that it includes an angle larger than .alpha. with the LCD. Both the analyzer and/or the polarizer may have a flat or a curved surface.

For an enlarged projection of images on a screen by means of a light valve projector, an optical image is put on a light valve and bundled light is sent through said light valve. Said light then passes through an appropriate projection lens system, which focuses an image on the screen. An appropriate light valve for such a projection system is a liquid crystal display, commonly referred to as an "LCD".
Two kinds of liquid crystal light valve projectors exist: OFF-axis projectors and ON-axis projectors.
FIG. 1 shows the optical path in an OFF-axis projection system. Said projection system comprises an OFF-axis projector 1 and a screen 2. The OFF-axis projector 1 comprises an illumination system 3, a field lens 4, a polariser 5, an LCD 6, an analyser 7 and a projection lens 8. The illumination system 3 comprises a lamp, a reflector, and an integrating system which converts the circular and non-uniform light distribution coming from the reflector into a rectangular and uniform illumination of the LCD 6. The field lens 4 images the illumination system into the entrance pupil of the projection lens 8. In this way, it ensures that the light with which the LCD 6 is illuminated is directed into this entrance pupil of the projection lens 8. The projection lens 8 images the illuminated LCD 6 on the screen 2. The line through the optical centres of the illumination system 3, the field lens 4 and the projection lens 8 is further called the optical axis 9 of the projector 1.
In case the OFF-axis projector 1 is a multi-light valve projector (for example a projector with three light valves), the optical path is more complex, because by means of a set of dichroic mirrors the light is splitted into 3 colours (red, green and blue), and after modulation of the light, these colours are recombined again. The OFF-axis projector then comprises an illumination system, three field lenses, three sets consisting of a polariser, an LCD and an analyser, and a projection lens. A line through the optical centres of the illumination system, one of the field lenses and the projection lens is an optical axis of the projector. The schematic description of the illumination and imaging system shown in FIG. 1 is not altered by these colour-splitting mirrors. In what follows the state of the art is described as if there were only one illumination system, one field lens, one set consisting of a polariser, an LCD and an analyser, and one projection lens.
The direction of the optical axis 9 of the projector 1 is different from the direction of the optical axis 10 of the projection lens 8. Both optical axes 9 and 10 include an OFF-axis angle .alpha. as shown in FIG. 1. This angle .alpha. can have any positive value, but in the most common OFF-axis configuration, the projector 1 is set up in such a way that the optical axis 10 of the projection lens 8 intersects with the bottom of the image of the screen 2.
If the OFF-axis angle .alpha. is zero, or in other words, if the direction of the optical axis 9 of the projector 1 is equal to the direction of optical axis 10 of the projection lens 8, the projector is called an ON-axis projector. FIG. 10a shows the minimum configuration of an ON-axis liquid crystal light valve projection system. It comprises an ON-axis projector 11 and a screen 2. The ON-axis projector 11 comprises the same parts as the OFF-axis projector 1 described hereinabove. Said same parts have been denoted by means of the same reference numerals.
FIG. 2 shows an image source of as well OFF-axis and ON-axis liquid crystal light valve projectors 1 and 11. Said image source comprises a polariser 5, an LCD 6 and an analyser 7. Although represented in FIG. 2 as three separate parts, two of the parts or the three parts can form one unit. The polariser 5 and the analyser 7 are both light polarising elements and have in their planes each an absorbing direction and a non-absorbing direction, the absorbing direction being perpendicular to the non-absorbing direction.
The LCD 6 comprises, with reference to the light direction, a front glass plate 15, a back glass plate 16 and sealed in between both glass plates 15, 16 a twisted nematic liquid crystal layer. The sides of the glass plates 15 and 16 not touching the twisted nematic liquid crystal layer, each have a layer with transparent image forming pixel electrodes. The twisted nematic LCD (TN-LCD) may be addressed with an active matrix. In such an active matrix TN-LCD, a switching device, such as a thin film transistor or a number of thin film diodes, is integrated on each pixel.
In FIG. 2, the non-absorbing direction 17 of the polariser 5 is perpendicular to the rubbing direction 18 of the front glass plate 15 of the LCD 6. Said rubbing direction 18 defines the preferred direction of the liquid crystal molecules at the interface with the front glass plate 15. The non-absorbing direction 19 of the analyser 7 is perpendicular to the rubbing direction 20 of the back glass plate 16. In a twisted nematic liquid crystal display, the rubbing directions at the opposite glass plates are perpendicular, and therefore the molecules form a 90 degrees twisted helix in the bulk as shown in FIG. 3a and FIG. 3b. FIG. 3a shows the distribution of the molecules 21 in a twisted nematic LCD between the front glass plate 15 and the rear glass plate 16 in the bright state. FIG. 3b shows the corresponding distribution in the dark state.
To obtain an optimum black level in an image projected by a projection system containing a polariser, an LCD and an analyser, the non-absorbing directions of these three elements must be correctly matched. Therefor, the analyser or the polariser may be installed rotatable around their normal.
The contrast of the image obtained with an LCD as light valve depends strongly on the angle of incidence of the light entering the LCD. It is by consequence LCD area and, by consequence, screen area dependent, what is explained by the following.
FIG. 4 shows the typical viewing angle characteristics of a twisted nematic LCD. The graphs are lines of equal contrast between the bright and dark state at the two corresponding driving voltages, with relative values between 3 and 300. The vertical axis shows the vertical angle of incidence between -40.degree. and 40.degree.. It presents the component of the light ray within the plane perpendicular to both the plane of the LCD and the horizontal image scanning direction of the LCD. The horizontal axis gives angles of incidence between -40.degree. and 40.degree. and is the component of the light ray within the plane perpendicular to the plane of the LCD and the vertical image scanning direction of the LCD.
FIG. 4 thus demonstrates the dependence of the contrast in function of the incident angle of the light which enters the LCD. The contrast changes much more in the vertical direction than in the horizontal direction of the screen. Moreover, the maximum contrast is not obtained for light rays with normal incidence but for light rays having a small incident angle in the vertical direction. This angle corresponds with the angle .alpha..sub.v shown on FIG. 3b. The angle .alpha..sub.v corresponds very well with the remaining tilt at dark state of the molecules in the twisted nematic liquid crystal layer.
FIG. 1 and FIG. 10a show that light rays enter the LCD under different angles. As a consequence of the phenomena shown in FIG. 4, without further measures being taken, an image projected by a projector using as light valve a twisted nematic LCD, will be non-uniform, which is differently contrasted in vertical direction.
FIG. 5 shows in another way how the LCD light transmission (vertical axis) depends on the angle of incidence (different graphs) and on the LCD drive voltage (horizontal axis). For angles of light incidence larger than 0.degree., the light transmission graphs show a minimum. This minimum determines the maximum obtainable contrast at that angle of incidence, as for higher drive voltages the contrast is negative. For larger positive angles of incidence, the minimum transmission value is higher and so the maximum obtainable contrast is lower. For smaller positive angles of incidence, the location of the minimum on the graph is shifted to a higher drive voltage and to a lower transmission value or higher obtainable contrast. For zero and negative angles of incidence of light, there is no minimum of transmission.
Another representation of the contrast dependence of the angle of incidence, also including the behaviour of the LCD in function of its drive voltage, is given by the graphs "0" in figures FIGS. 6a, 6b and 6c. The normalised intensity on the screen is displayed on these figures in function of the LCD drive voltage for a projection system as illustrated by FIG. 1. FIG. 6a shows the intensity measured at the top of the display screen; FIG. 6b shows the intensity in the middle of the screen; FIG. 6c shows the intensity measured at the bottom of the screen.
FIG. 6a shows that in areas of the image where the angle of incidence of light is larger, the intensity of the projected image has a minimum value for a specific drive voltage of the LCD. This is the case at the top of the image in a projection system as illustrated in FIG. 1. For drive voltages above the voltage of minimum intensity, the contrast is even negative. If otherwise the drive voltage should be equal all over the LCD, such an intensity minimum will appear on the screen at a specific angle of incidence and be visible as horizontal darker bar.
FIG. 6b and FIG. 6c show that in areas of the image where the angle of incidence is smaller, such a minimum of intensity (or in other words maximum of contrast) does not occur. There, the limitation is determined by the maximum LCD drive voltage allowed.
For the above reasons, in practice the LCD drive voltages are chosen so as to get a uniform black level or minimum intensity all over the screen. The limit is thereby determined by what can be obtained in the area of larger angles of incidence, and so does not result in the best contrast possible in other areas of the screen.
In order to obtain a better contrast and better uniformity of contrast without loss of other picture quality, various methods of contrast enhancement and apparatus with improved contrast are known.
Various apparatus have additional physical items with reference to the minimum projector set-up as described in FIG. 1.
In U.S. Pat. No. 5,576,854, a quarter-wave compensator plate is disposed between the polariser and the liquid crystal light. This solution is only suitable for the reflective set-up described in the patent and is not applicable for projection with TN-LCDs.
In U.S. Pat. No. 5,371,559, a stop is disposed inside the projection lens, forming an aperture of the lens assembly decentered from the optical axis of the lenses of the projection lens assembly in the vertical scanning direction of the liquid crystal panel. The blocking of the light rays at the entrance pupil of the lens reduces the efficiency of the projection system, resulting in a lower light output of the projector.
In U.S. Pat. No. 5,375,006, contrast improvement in a projector using TN-LCDs is obtained by using (uniaxial) birefringent films. In some of the claims, the films are even inclined with respect to the optical axis. This solution however complicates the complete stack of elements of the LCD light-modulating device, because two new optical surfaces are introduced. This leads to light loss due to extra reflections. If the films are optically coupled to minimise this light loss, then the LCD itself becomes thicker, and more difficult to cool. Moreover, these thin birefringent films are also sensitive to temperature changes and mechanical stress caused by the temperature differences in a high light-output projector.

Contrast improvement in liquid crystal light valve projectors


Methods and systems for directly and securely transferring encrypted medical data between two remote locations, such as an imaging site and a diagnostic site, wherein the diagnostic site is not within a data transfer network utilized by the imaging site. The invention allows the diagnostic site to receive medical data and view the data using a thin client viewer, and allows the diagnostic site to register as an in-network site.

It is common place in today's environment to find medical care providers with an assortment of medical devices that produce digital images that need to be subsequently analyzed by specialist to identify potential health issues with the highest confidence. Examples fields making use of medical imaging would include radiology, cardiology imaging, and radiotherapy device (X-ray, CT, MM, ultrasound, etc.), and increasingly in devices in other medical domains such as ophthalmology and dentistry. Transmission of these images, or studies, are complicated by the fact that they are subject to HIPAA requirements, whereby all entities that take possession of the studies, even when ephemeral, must be pre-qualified as HIPAA compliant. One solution to this problem is to establish a VPN between the medical provider and the diagnostic lab. However, this solution suffers from complexity and cost. Installing a VPN between two providers commonly means segregating the network at both ends to limit what each of the other parties can see. While doing this between a single set of providers may seem straightforward, it quickly become less tractable when a single provider needs to communicate over VPN with a plurality of other providers. This means creating a separate zone for each of the other providers, and installing a separate VPN for each of the other providers.
Another popular method of transmitting the imaging data is to store it on a CD, DVD, or other media and mail through the postal system or other transportation provider. In previous years, when networks were generally slower, this method held appeal. However, it suffers from lack of immediacy given that it is generally quicker to send data over todays network than to suffer the delays in physical transit for all but the largest of transmissions. Physical media is also prone to being damaged, stolen, or lost in transit.
What is needed is a system that is quick and easy to install and configure, complies with all regulations regarding privacy and security, and provides for immediate delivery with confirmation and traceability.

This patent is subject to a terminal disclaimer.

Methods and systems for transferring secure data and facilitating new client acquisitions


A method for illuminating a liquid crystal display device, a back-light assembly for performing the same and a liquid crystal display device using the same can improve the front luminance and production yield. Lights from a lamp is incident to a LCD panel side, which are then primarily diffused for a uniformity of the luminous flux of the incident lights. The luminous flux of the primarily diffused lights is condensed with respect to a first orientation component on a plane in parallel with the LCD panel, and then partially and secondarily diffused for extending a view angle of pixels of the LCD panel. After the luminous flux of the secondarily diffused lights is condensed with respect to a second orientation component perpendicular to the first orientation on the parallel plane, the condensed lights are illuminated onto the LCD panel. A diffusion sheet for secondarily diffusing the luminous flux and a condensing sheet for condensing the second orientation component are formed by a single sheet to reduce the manufacturing process of the liquid crystal display device. Also, a defect produced from respective sheets is minimized to enhance the yield.

1. Field of the Invention
The present invention relates to a method for illuminating in a liquid crystal display device, a back-light assembly for performing the same and a liquid crystal display device using the same, and more particularly, to a method for illuminating a liquid crystal display device and a liquid crystal display device using the same. The method for illuminating a liquid crystal display device enhances the front luminance of the liquid crystal display device, reduces the manufacturing process steps and renders a thin and light liquid crystal display device.
2. Description of the Related Art
Generally, a liquid crystal display device applies a voltage to a specific molecular arrangement of a liquid crystal to convert its molecular arrangement. Then, the liquid crystal display device converts the changes of the optical properties such as birefringence, optical linearity, dichroism and optical scattering characteristics of liquid crystal cells that emits light according to the molecular arrangement, and uses the modulation of the light of the liquid crystal cells.
The liquid crystal display device is largely sorted into a TN (Twisted Nematic) type and a STN (Super-Twisted Nematic) type. The liquid crystal display device is, according to the driving method, sorted into an active matrix display type, which uses a switching device and a TN liquid crystal, and a passive matrix type, which uses an STN liquid crystal.
A distinguishable difference of two types is that the active matrix display type is a TFT-LCD that drives an LCD by using a TFT and that the passive matrix display type does not have such a complicated circuit associated with a transistor because it has no transistor.
Since the liquid crystal display device is a passive light element incapable of emitting light itself, the images are displayed by using a back-light assembly attached to the rear plane of the liquid crystal panel.
Recently, there are several structures developed for contriving the slim and light products so as to have the leading edge of the competitiveness. Especially, the light-weight becomes a more important factor in view of the adoption chiefly to a portable computer, etc.
In such a liquid crystal display device, the role and function of the back-light assembly have been considered as increasingly important, because the dimension, light efficiency and so on differ depending on the back-light assembly structure to affect on overall mechanical/optical characteristics of the liquid crystal display device.
A structure of a general back-light assembly used in the liquid crystal display device is disclosed in U.S. Pat. No. 5,467,208.
FIG. 1 schematically shows the foregoing back-light assembly of the conventional liquid crystal display device. FIG. 2 schematically shows an illuminating process via the back-light assembly of the conventional liquid crystal display device.
Referring to FIGS. 1 and 2, the liquid crystal display device includes a lamp 1 for generating lights, a light guide plate 4 for guiding the lights from the lamp 1, and a lamp housing 2 installed to the side plane of the light guide plate 4 surrounding the lamp 1.
The lamp 1 employs a cold cathode, and the lights generated from the lamp 1 are incident via the side plane of the light guide plate 4.
The lamp housing 2 is formed with a reflection plate 6 on the inner surface thereof to reflect the lights from the lamp 1 toward the side plane of the light guide plate 4, thereby enhancing the efficiency of the lights from the lamp 1.
The light guide plate 4 is formed of a transparent material of plastics such as acrylic resin for forming a panel shape having a sloped lower plane and a horizontal upper plane (alternatively, a sloped upper plane) to allow the lights generated from the lamp 1 to advance toward an LCD panel (not shown) seated on the upper portion after passing through the upper plane of light guide plate 4. Accordingly, the lower plane of light guide plate 4 is formed with various patterns such as a minute dotted pattern printed for changing the advancing direction of the lights from lamp 1 into toward the LCD panel side.
A reflection plate 6 is formed under the lower plane of light guide plate 4, and a diffusion sheet 8, a first prism sheet 10, a second prism sheet 12 and a protecting film 14 are sequentially stacked on the upper plane of light guide plate 4.
The reflection plate 6 again reflects the lights that are not reflected by the minute dotted pattern in the lights which have been generated from the lamp 1 to advance toward the lower plane of the light guide plate 4 toward the upper plane of the light guide plate 4, thereby improving the consistency of the lights transmitted to the upper plane of the light guide plate 4 while decreasing the optical loss of the lights incident to the LCD panel. As described above, the light guide plate 4 and the reflection plate 6 guide the lights generated from the lamp 1 toward the upper plane of the light guide plate 4.
At this time, the lights passing through the upper plane of the light guide plate 4 include the lights outgoing by being to be sloped at various angles as well as the lights outgoing perpendicularly to the upper plane thereof.
The diffusion plate 8 placed between the light guide plate 4 and the first prism sheet 10 scatters the incident lights from the light guide plate 4 to prevent the partial concentration of the lights. Additionally, the diffusion plate 8 decreases the sloped angle of the lights advancing toward the first prism sheet 10 with respect to the first prism sheet 10.
The first prism sheet 10 and the second prism sheet 12 are formed in a manner that triangular bar-shaped prisms are formed to respective upper planes in a regular arrangement, and the prism arrangement of the first prism sheet 10 and that of the second prism sheet 12 are provided to cross each other at a predetermined angle.
The first and second prism sheets 10 and 12 respectively serve for condensing the lights diffused by the diffusion plate 8. By doing so, the vertical incidence with respect to the protecting film 14 of the lights having passed through the first and second prism sheets 10 and 12 becomes most favorable.
For this reason, almost all lights passing through the first and second prism sheets 10 and 12 advance perpendicularly, so that the luminance distribution over the protecting film 14 is uniform.
The protecting film 14 formed on the second prism sheet 12 not only protects the surface of second prism sheet 12 but also diffuses the lights for uniform distribution of lights. The LCD panel 15 is installed on the protecting film 14.
In other words, in the back-light assembly structure of the conventional liquid crystal display device, as shown in FIG. 2, the lights are generated from the lamp to be incident to the LCD panel 15 placed on the protecting film 14 of the back-light assembly via the path provided by the diffusion, condensing, condensing then to diffusion.
However, when applying the illuminating method of the back-light assembly, the above-mentioned conventional liquid crystal display device requires several sheets for condensing/diffusing the lights on/from the upper portion of the light guide plate to therefore complicate the assembling process. Furthermore, the plurality of sheets used for the device may render high probability of puckering to degrade reliability of products and increase the manufacturing cost.
In addition, in the conventional diffusion plate, a plurality of beads are distributed over the front plane and rear plane of the same density to distribute the lights incident from the light guide plate to the rear plane of the diffusion plate.
When constructing the diffusion plate having the aforesaid structure, the precision of condensing function conducted by the first and second prism sheets stacked on the diffusion plate is degraded to lower the front luminance when the lights incident from the lower portion of the diffusion plate are aslant.
Moreover, in the conventional liquid crystal display device, if the protecting film is eliminated to decrease the number of sheets stacked in the back-light assembly, the lights condensed by the first and second prism sheets having the triangularly-shaped section are concentratedly condensed only to the direction that is nearly perpendicular to the plane of the LCD panel to be incident to the LCD panel. The lights condensed as described above cause interference with the pixels of the LCD panel, which in turn incites a moiré phenomenon of producing wave pattern throughout the screen.

Method for illuminating liquid crystal display device, a back-light assembly for performing the same, and a liquid crystal display device using the same


A system for transporting messages that originate potentially with a third party to one or more other parties each of which is communicating with the other over a transmission system and videophones is disclosed. The messages in the form of video images remain on both videophone displays for a variable length of time. The system enables viewing of an important message by a significant number of individuals over their videophones. The system utilizes the captive time that two parties experience during the setup and connection period for a real time communication.

1. Field of the Invention
This invention pertains to the field of communication systems. More particularly, this invention relates to a method and a means for distributing important messages for viewing via a pathway that is independent of traditional broadcast mediums such as television.
2. Art Background
Public broadcast systems such as the radio or television are commonly employed for the distribution of messages having key importance. For example, such broadcast systems are usually employed to provide warning of an impending hurricane threat to a coastal area. Typically, such emergency warning messages are continuously played over the radio and television as interruptions on regular programming, or in the form of official commercials. In the past, such broadcast systems have permitted transmission of a single message to multiple listeners or viewers relatively efficiently.
However, the continual development of alternative transmission systems for both audio and video information, such as wide area networks, and the development of cable television systems that provide hundreds of channels along with sophisticated "personal agents" to select the images viewed on a particular channel is eroding the capability of message originators to efficiently reach a large audience. Given such increased capability by viewers to select from all the available information sources and to select the information to be received, a message originator may encounter increasing difficulty in ensuring that messages are viewed by the appropriate viewers.
Some prior messaging systems suffer from such limitations due to a reliance on a primarily single direction broadcast mode. Such systems include, for example, the radio or television networks that currently exist. Other prior messaging systems are limited due to a reliance on a communication mode that requires a first party to specifically send a message only to a second party, often at a specific request of the second party.
For example, in U.S. Pat. No. 4,734,765, Okada et. al. describe a center-to-end type information system. Such a system permits the transmission of several messages stored in one location to multiple users, but only if a subscriber requests access to a server system and requests information.
In U.S. Pat. No. 5,132,992, Yurt et. al. also describe an audio and video transmission and receiving system. Yurt et. al. describe various forms of audio and video information that can be sent between a source library that stores data and multiple subscribers. Yurt et. al. allow for transmission over standard telephone, cable or satellite broadcast channels. However, the system of Yurt et. al. requires that a requesting party specifically log on and access the desired information. Unfortunately, such a system does not ensure that a person who is not looking for specific information will be alerted to an important public service message.
Brandon et. al, in U.S. Pat. No. 4,924,303 describe a system for the retrieval of television still frame and audio segments. Brandon et. al. require that two signal networks be used simultaneously, including the telephone system for control and audio information and a separate signal network for the video information. Unfortunately, the system of Brandon et. al. requires that a user request access and select a specific image and audio message and a one way type transmission system.
Auber in U.S. Pat. No. 4,896,347 describes an interactive video communications system wherein an information server is connected by the public switched telephone network. However, the system of Auber requires the aid of control signals that enable a user or subscriber who specifically connects to the server to access information and messages.
In U.S. Pat. No. 4,685,122, Deveron et. al. describe an interface circuit and a method that permits interactive audio/visual demonstrations controlled by DTMF tones from a telephone and permits viewing of pre-recorded messages via telephone control. Unfortunately, the system of Deveron et al. requires that a party specifically request the messages. Moreover, the control signals and not the actual message is transmitted over the various networks in the system of Deveron et al.
Jones et al. in U.S. Pat No. 5,193,110 describe a multi-port switching hub to provide a plurality of application ports or messages to a number of users through the telephone system. However, Jones et. al. teach of a single user receiving information by request only.
A system for receiving messages for viewing over a videophone is discussed in relation to a videophone answering machine by Hasimoto U.S. Pat. No. 4,829,555.
The above systems, however, do not address the problem of providing messages for viewing by parties that are not necessarily responsible for the message content.

Apparatus and method for utilizing display phone set-up time to provide third party controlled messaging


A multi-layer article includes a first polymer layer bonded to a barrier layer, which is bonded to a second polymer layer. The first polymer layer can include a fluoroelastomer. The second polymer layer can be a non-fluorinated polymer layer. The barrier layer can include a polymer derived from vinyl acetate.

Fluorine-containing polymers (also known as "fluoropolymers") are a commercially useful class of materials. Fluoropolymers include, for example, crosslinked fluoroelastomers and semi-crystalline or glassy fluoroplastics. Fluoroplastics are generally of high thermal stability and are particularly useful at high temperatures. They can also exhibit extreme toughness and flexibility at very low temperatures. Many of these fluoroplastics are almost totally insoluble in a wide variety of solvents and are generally chemically resistant. Some have extremely low dielectric loss and high dielectric strength, and can have unique non-adhesive and low friction properties. See, e.g., F. W. Billmeyer, Textbook of Polymer Science, 3d ed., pp. 398-403, John Wiley & Sons, New York (1984).
Fluoroelastomers, particularly the copolymers of vinylidene fluoride with other ethylenically unsaturated halogenated monomers such as hexafluoropropylene, have particular utility in high temperature applications such as seals, gaskets, and linings. See, e.g., R. A. Brullo, "Fluoroelastomer Rubber for Automotive Applications," Automotive Elastomer & Design, June 1985; "Fluoroelastomer Seal Up Automotive Future," Materials Engineering, October 1988; and W. M. Grootaert et al., "Fluorocarbon Elastomers," Kirk-Othmer, Encyclopedia of Chemical Technology, vol. 8, pp. 990-1005 (4th ed., John Wiley & Sons, 1993).
In the automotive industry, increased concern with evaporative fuel standards has led to the need for fuel system components that have improved barrier properties. This helps reduce the permeation of fuel vapors through automotive elements such as fuel filler lines, fuel supply lines, fuel tanks, and other elements of an automobile fuel system. Multi-layer tubing and other articles containing a fluoropolymer layer have been used in such automotive elements to provide a chemically resistant permeation barrier.
Also, certain fuels may include additional components, such as oxygenating agents or other additives. Such multicomponent fuels may react in a less than optimum way with individual component materials of an article, which can lead to incomplete permeation protection.

Multi-layer articles including a fluoroelastomer layer and a barrier layer and method of making the same


A process for making an adhesive comprising allowing a carrier web coated with a thermal free-radically polymerizable mixture to remain in a heat exchange medium for a time sufficient to subdue the reaction exotherm and maintain a reaction temperature by thermal contact of the polymerizable mixture with the heat exchange medium and to affect conversion of the coating to an adhesive layer, preferably to a pressure sensitive adhesive layer, wherein the coating is a substantially solvent-free thermally initiated polymerizable mixture comprised of at least one free radical monomer, at least one thermal initiator, optionally, at least one cross-linker and optionally, at least one co-monomer.

Polymeric materials based on acrylic monomers are known in the art, including those whose primary use is for pressure sensitive adhesives (for example, U.S. Reissue No. 24,906). PSAs are typically copolymers of a major proportion of alkyl esters of acrylic acid and a minor portion of at least one modifying monomer, such as (meth)acrylic acid, (meth)acrylamide, (meth)acrylonitrile and the like. Acrylate-based polymers are widely used as adhesives industry for reasons of costs, raw material availability, ease of reaction and properties.
However, some acrylate monomers are highly volatile and require expensive equipment. For example, methyl acrylate is a highly volatile monomer and using such a monomer in an adhesive formulation requires the use of coating equipment that is certified as Class 1, Division 2, Group D for use with flammable volatile materials as designated by the US National Electric Code. Coaters of this type tend to be very expensive and hazardous to operate. A number of polymerization methods have been used, but few, if any deal adequately with the problems of highly volatile monomers.
It is known in the literature and in the industry that there are at least five different feasible methods for the production of acrylic-based pressure-sensitive adhesives (hereinafter "PSAs"). These known methods include solution polymerization, emulsion polymerization, suspension polymerization, irradiation by high energy particulate matter (for example, electron beams or gamma rays), and ultraviolet light (hereinafter "UV") photopolymerization. As explained below, there are disadvantages and/or limitations incurred with the use of each known process.
Solution polymerization is used because it is relatively easy to control the significant reaction exotherm characteristically associated with acrylate polymerization. However, elaborate drying ovens with massive exhaust ducts and high temperatures are required to carry away the volatile organic compounds (hereinafter "VOCs") after coating from solution. Furthermore, to prevent the VOCs from being vented to the atmosphere (with resulting pollution and solvent loss), expensive VOC recovery equipment is necessary. Safety hazards in such operations are also significant, as the VOCs are extremely flammable and precautions must be taken to avoid explosive mixtures in the oven and recovery systems. Further, coatings applied from solution have a limitation as to the thickness of the coating that can be deposited in one pass through the coater. Thus, with coatings above about 0.125 mm, multiple coating layers must be deposited in successive trips through the coater to avoid blistering of the coating due to solvent evaporation.
While emulsion and suspension polymerizations have minimized the problems associated with the handling and evaporation of flammable solvents, heat must be supplied to remove water from the coating and essentially the same equipment must be employed. Though high solids coatings are possible, the higher heat of vaporization of water as compared to VOCs offsets this benefit and about the same total energy for drying is required. Drying times are relatively long, thus limiting production rate. One of the most serious limitations of the emulsion polymerization process is the water sensitivity of the resulting polymers (caused by the emulsifying agent, which is carried along in the process and becomes part of the final adhesive). A further limitation of this process is that highly polar monomers, which are water miscible, are difficult to incorporate into the copolymer during polymerization and considerable homopolymerization of such monomers can occur in the aqueous phase.
More recently, development work has been done with polymerization processes that employ either ultraviolet light or electron beams. One which stresses electron beam curing is U.S. Pat. No. 3,897,295, in which the composition subject to the electron beam includes an acrylate monomer selected from a particular specific group, and a homopolymer or copolymer of a substance or substances selected from the same group. The polymer is dissolved in the monomer and the monomer is ultimately polymerized to bind the adhesive together.
The disadvantage of using polymerization processes involving an electron beam, though, is that, generally, it is a rather indiscriminate polymerization process. In polymerization processes using an electron beam, the particulate bombardment of the polymerizable mixture can lead to chain scission of the developing polymer, resulting in an inability to control the molecular weight of the polymer and the crosslink density into the most desired range.
In order to avoid the above-discussed disadvantages incurred with the use of an electron beam, some have chosen to use a one step low-intensity (for example, 0.1 to 7 mW/cm.sup.2) UV photopolymerization process. See, for example, U.S. Pat. No. 4,181,752. Whereas the use of relatively low intensity UV light is very desirable for building higher molecular weight acrylic PSA's with good performance properties, the use of low intensity UV light leads to low manufacturing rates, so an increase in the speed of the photopolymerization process would be desirable. However, if one attempts to increase the speed of the low intensity UV light-based process by increasing the amount of the photoinitiator employed (for example, benzoin ethers, benzil ketals, etc.), undesirable lower molecular weight polymers will be obtained.
Furthermore, for thick adhesives an uneven polymerization from the front surface to the back surface of an irradiated adhesive composition occurs due to absorption of the UV radiation by the polymerizable mixture through the thickness of the coating. This results in a gradient in the conversion, molecular weight and distribution through the thickness of the cured material, which can lead to inferior performance of the final PSA product. In addition to the above discussed considerations, UV light-based processes generally require rigorous exclusion of oxygen during the polymerization process and are limited to essentially non-volatile acrylic monomers and to constructions that are substantially transparent to UV irradiation. Furthermore, controlling the polymerization reaction exotherm is still necessary.
A number of modifications and variations of the UV light-based processes are known. (See for example, U.S. Pat. Nos. 4,415,615 and 4,513,039). For example, a pressure sensitive adhesive composition is prepared by coating the polymerization mixture onto a web and polymerizing via UV irradiation, wherein the polymerization step is carried out in an inert atmosphere (Japanese Kokai No. HEI 5-5014). Alternatively, the UV light polymerization step is carried out while the coated web is immersed in water Japanese Kokai. No. HEI 4-41576).
In view of the foregoing discussed disadvantages and limitations that exist with the use of conventional polymerization processes, improvements are continuously desired and sought by those within the industry. It was against this background that an improved polymerization process for producing adhesives, and in particular acrylic-based adhesives and tapes was sought.


A distortion compensator updating and selecting a distortion compensation coefficient applied to a digital transmission signal so as to reduce the difference between the digital transmission signal and a digital feedback signal is disclosed. The distortion compensator includes a control part that controls the level of an input signal to an analog-to-digital conversion part outputting the digital feedback signal in accordance with the magnitude of the amplitude of the digital transmission signal.

1. Field of the Invention
The present invention relates generally to nonlinear distortion compensators in radio transmitters, and more particularly to a distortion compensator of a digital pre-distortion type.
2. Description of the Related Art
In this type of technical field, the digital pre-distortion (DPD) technique has been widely used to compensate for the nonlinear distortion of a transmission signal caused by the power amplifier of a radio transmitter.
FIG. 1 is a block diagram showing part of a radio transmitter with a DPD distortion compensation function. Referring to FIG. 1, the radio transmitter includes a DPD unit 102, a digital-to-analog converter part (D/A) 104, a frequency converter part 106, a high frequency amplifier part 108, a distributor part 110, a frequency converter part 112, and an analog-to-digital converter part (A/D) 114. The DPD unit 102 includes an amplitude and phase correction part 116, a look-up table 118, an error detection part 120, and a delay part (D) 122.
A modulated baseband digital transmission signal is input to the DPD unit 102, where the digital transmission signal is corrected by pre-distortion compensation. Thereafter, the digital transmission signal is converted into an analog transmission signal in the D/A 104. The analog transmission signal is frequency-converted to a radio frequency signal by the frequency converter part 106, and is amplified in the high frequency amplifier part 108 to be transmitted by radio from an antenna part (not graphically represented) via the distributor part 110. On the other hand, the transmission signal is extracted by the distributor part 110 as a feedback signal, and is frequency-converted to a baseband signal in the frequency converter part 112 to be input to the A/D 114. The output of the A/D 114 is input to the DPD unit 102. The high frequency amplifier part 108 and the other analog elements may provide distortion to a signal to be transmitted because of not only their own nonlinear characteristics but also their dependence on the environment of use, such as variations in temperature and over time. The distortion is detected in the error detection part 120 of the DPD unit 102 as the difference or error between the digital feedback signal from the A/D 114 and the digital transmission signal, whose timing has been adjusted by being delayed by the delay part 122 so as to be compared with the feedback signal. In the DPD unit 102, the distortion compensation coefficients of the look-up table 118 are adaptively updated so as to reduce the error detected in the error detection part 120. Then, an appropriate distortion compensation coefficient is selected in accordance with the level of the digital transmission signal, and the digital transmission signal is multiplied by the selected distortion compensation coefficient in the amplitude and phase correction part 116. The distortion compensation coefficient functions to predistort the amplitude and phase of the digital transmission signal so as to offset nonlinear distortion components introduced into the transmission signal by the analog elements. For instance, Japanese Laid-Open Patent Applications No. 63-208330, 2001-345718, and 2001-189685 disclose distortion compensators as described above.
The amplitude of the modulated baseband digital transmission signal varies in level from high to low. Therefore, a feedback signal of a high amplitude level is obtained for a digital transmission signal of a high amplitude level, and a feedback signal of a low amplitude level is obtained for a digital transmission signal of a low amplitude level. In this case, if the amplitude level of the analog feedback signal input to the A/D 114 is lowered, the number of bits effectively used in the A/D 114 is reduced. As a result, the accuracy of the digital feedback signal may be reduced.
The lowest amplitude level of a digital transmission signal may be as low as approximately one several-hundredth of its highest amplitude level, or be lower than its highest amplitude level by tens of dB. If the number of bits of the A/D 114 is 12, the A/D 114 may represent 212=4096 amplitude levels. If the highest amplitude level, which is 4096, is reduced to 1/128 (2−7) thereof, the amplitude level becomes 32=25, which is a reduction of approximately 20 dB. When the amplitude level is 32, only five of the 12 bits of the A/D 114 are used, which means that the remaining seven bits are not effectively used. If the number of bits effectively used in the A/D 114 is thus reduced, the accuracy of the digital feedback signal generated therein and the accuracy of the error signal generated in the error detection part 120 may be decreased, resulting in a reduction of the accuracy of distortion compensation.