A Viterbi decoder is configured for outputting a prescribed plural number of decoded bit pairs upon execution of each backtracing operation based on accessing a second prescribed number of state history table entries from a surviving state history table. The outputting of more bits per backtrace operation lowers the number of memory accesses, and enables the Viterbi decoder to maintain a high throughput of data flow while maintaining an acceptable bit error rate.

1. Field of the Invention
The present invention relates to implementation of a Viterbi decoder in a wireless receiver, for example a IEEE 802.11a based Orthogonal Frequency Division Multiplexing (OFDM) receiver.
2. Background Art
Local area networks historically have used a network cable or other media to link stations on a network. Newer wireless technologies are being developed to utilize OFDM modulation techniques for wireless local area networking applications, including wireless LANs (i.e., wireless infrastructures having fixed access points), mobile ad hoc networks, etc.. In particular, the IEEE Standard 802.11a, entitled "Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications: High-speed Physical Layer in the 5 GHz Band", specifies an OFDM PHY for a wireless LAN with data payload communication capabilities of up to 54 Mbps. The IEEE 802.11a Standard specifies a PHY system that uses fifty-two (52) subcarrier frequencies that are modulated using binary or quadrature phase shift keying (BPSK/QPSK), 16-quadrature amplitude modulation (QAM), or 64-QAM.
Hence, the IEEE Standard 802.11a specifies an OFDM PHY that provides high speed wireless data transmission with multiple techniques for minimizing data errors.
A particular concern in implementing an IEEE 802.11 based OFDM PHY in hardware involves providing a cost-effective, compact device the can be implemented in smaller wireless devices. Hence, implementation concerns typically involve cost, device size, and device complexity.
For example, a forward error correction technique, known as convolutional coding with Viterbi decoding, has been used to provide encoded data to reduce bit errors. The purpose of forward error correction (FEC) is to improve the capacity of a wireless channel by adding some carefully designed redundant information to the data being transmitted through the channel. The process of adding this redundant information is known as channel coding. Convolutional coding and block coding are the two major forms of channel coding. Convolutional codes operate on serial data, one or a few bits at a time. Block codes operate on relatively large (typically, up to a couple of hundred bytes) message blocks. There are a variety of useful convolutional and block codes, and a variety of algorithms for decoding the received coded information sequences to recover the original data.
Convolutional codes are usually described using two parameters: the code rate and the constraint length. The code rate, k/n, is expressed as a ratio of the number of bits into the convolutional encoder (k) to the number of channel symbols output by the convolutional encoder (n) in a given encoder cycle. The constraint length parameter, K, denotes the "length" of the convolutional encoder, i.e. how many k-bit stages are available to feed the combinatorial logic that produces the output symbols. Closely related to K is the parameter m, which indicates how many encoder cycles an input bit is retained and used for encoding after it first appears at the input to the convolutional encoder. The m parameter can be thought of as the memory length of the encoder.
Viterbi decoding has the advantage that it has a fixed decoding time. It is well suited to hardware decoder implementation. But its computational requirements grow exponentially as a function of the constraint length K. In particular, the convolutional encoding of the data is accomplished using a shift register (composed of a prescribed number of flip flops) and associated combinatorial logic that performs modulo-two addition (e.g., XOR addition).
A significant characteristic of the convolutional encoding is that an input bit to the convolutional encoder (having, for example, two flip flops) has an effect on three successive pairs of output symbols. In particular, the state of a two-flip-flop register transitions to a prescribed new state in response to the next input; consequently, the output symbols of the convolutional encoder will follow a prescribed transition to one of two states (from a domain of 2(K-1) possible states) based on: (1) the state of the shift register, and (2) the input data. For example, in the case of a ½ convolutional encoder having 6 flip flops with a state of "19" (decimal) (i.e., 110010, left-most bit being the least significant bit and right-most bit being the most significant bit), an input bit having a value of "1" or "0" would cause the shift register to change to a state of "39" or "38", respectively. Both the state transitions of the flip flops and the output symbols, also referred to as auto-correlation of the input data, can be characterized by respective output tables having 2(K-1) rows, and 2k columns, where K is the constraint length and k is the number of bits input to the encoder for each cycle.
The maximum size code word for IEEE 802.11a packets is 215 bits, and the ½ convolutional encoder (n=2, k=1) has 64 possible states based on a constraint length K=7 (i.e, based on the convolutional encoder having six (m=6) flip flops). In particular, given N bits for an input data stream, there are a possible 2N state transitions that may occur by the encoded data during the encoding of the data stream.
The Viterbi decoder determines the most likely state (i.e., encoded value) based on evaluating the sequence of received encoded code words. In other words, the Viterbi decoder determines, given an initial zero state of the encoder, the most probable value for a given encoder state relative to the respective transitions from other detected states; determining a state transition implicitly identifies the encoded data and vice versa. In summary, the Viterbi decoder, in response to receiving a pair of channel symbols, stores the received channel symbol pair and determines a distance metric (also referred to herein as an error metric) between the received channel symbol pair and the possible channel symbol pairs (which map to the respective possible encoder states). The mapping of an existing encoder state to a new state based on the input bit value is often illustrated using a Trellis diagram. As successive channel symbol pairs are received, the respective error metrics are applied to the prior possible encoder states to determine which of the prior possible encoder states become surviving predecessor states having the lowest respective accumulated errors.
The accumulated error value for each encoder state at each iteration (i.e., each instance of receiving a corresponding channel symbol pair) is stored in an accumulated metric table that specifies the accumulated error metric, for each possible encoder state, at each time instance. The surviving predecessor state for each encoder state at each iteration (i.e., each instance of receiving a corresponding channel symbol pair) is stored in a surviving state history table that specifies the surviving predecessor state, for each possible encoder state, at each time instance. Once the accumulated metric table and the surviving state history table has been populated with the respective values generated from stream of channel symbol pairs, a traceback algorithm recovers the original encoded stream based on tracing back from the state having minimum accumulated error in the accumulated metric table for a given instance (starting with the last time instance representing the last received channel symbol pair), to the prior state specified in the surviving state history table. Additional details of Viterbi decoding are described by Fleming, "A Tutorial on Convolutional Coding with Viterbi Decoding", 2001, available on the World Wide Web at the exemplary web pages http://pw.netcom.com/˜chip.f/viterbi/tutorial.html, http://pw.netcom.com/˜chip.f/viterbi/algrhms.html and http://pw.netcom.com/˜chip.f/viterbi/algrthms2.html.
A particular problem of conventional Viterbi decoders involves the large number of computations required over the entire length of the convolutional encoded data stream. Since a code word can have a length of up to 4095 bytes, the storage of all state transitions during decoding of an entire code word could require at least 2-3 Mbytes of memory. One solution is to utilize a prescribed minimum number of instances (i.e., the traceback depth) to decode the first pair (i.e., two bits) of channel symbols. For example, the above-referenced Fleming document suggests a traceback depth of K×5 for Viterbi decoding a pair of channel symbols. Hence, a traceback decoding window having a depth of K×5 is used to decode a pair of convolutionally-encoded data bits.
However, even the use of a traceback decoding window of depth K×5 to decode a pair of convolutionally-encoded data bits may be insufficient for providing an economical implementation of an ODFM PHY capable of decoding the high data rates specified by IEEE 802.11a (e.g., 54 Mbps). In particular, use of a 25-instance window (50-bit window) (K=5) in a Viterbi decoder using a 40 MHz clock limits the output data rate to 3.2 Mbps (2/(25/40 MHz)=3.2 Mbps), assuming a single read port state history table.
Further, conventional implementations require complex addressing schemes to overcome memory access latencies caused by the substantially large number of data accesses required per decoding cycle. For example, assuming a backtracing window depth of D=30 instances, typically a Viterbi decoder, upon storing the first 30 pairs of samples, would retrieve the first 30 pairs of encoded data bits (e.g., pairs 0-29) to obtain the first pair of decoded data (e.g., for instance 0); the decoder would then retrieve the 30 pairs (e.g., pairs 1-30) needed for the next decoding sequence (e.g., instance 1). Hence, the generation of 30 pairs of decoded data would require 900 memory accesses.

Viterbi decoder utilizing partial backtracing


A bidirectional voltage translator (102) includes a first port (200/400), a second port (202/402) and a bidirectional translator circuit (208-215/404-408, 410, 412-415) coupled between the first and second ports (200/400,202/402). The first and second ports (200/400,202/402) communicate signals at a first voltage level and a second voltage level, respectively. The second voltage level is different from the first voltage level. When a first port signal input at the first voltage level at the first port (200/400) is detected, the bidirectional translator circuit (208-215/404-408, 410, 412-415) translates the first port signal into the second voltage level at the second port (202/402) and disables translation of a signal at the second port (202/402) to the first port (200/400). When a second port signal input at the second voltage level at the second port (202/402) is detected, the bidirectional translator circuit (208-215/404-408, 410, 412-415) translates the second port signal into the first voltage level at the first port (200/400) and disables translation of a signal at the first port (200/400) to the second port (202/402).

Electronic systems employ voltage translators to interface electronic devices that operate at different voltage levels. Such voltage translators are sometimes bidirectional to facilitate transferring of data. Existing bidirectional voltage translators utilize a read/write control line to control the direction of data communication. The read/write control line is controlled by one of the electronic devices coupled to the bidirectional voltage translator. Due to hardware limitations, some electronic devices are unable to accommodate the read/write control line. Existing off-the-shelf cabling also does not accommodate the read/write control line. What is needed, therefore, is a bidirectional voltage translator that does not utilize a read/write control line.
It is also beneficial to implement a bidirectional voltage translator using low cost discrete components.


An inexpensive and easily maintained gas burner assembly achieves the manufacturing and maintenance advantages of the conventional sand pan burner design in addition to the heat output and fuel efficiency of more complex burner designs. The invention comprises a tray having a bottom wall and sidewalls defining an interior and an open top. A cover channel having a midsection segment and at least two downwardly depending flanges is adapted to fit in the interior of the tray to form a mixing chamber between the cover channel and the tray. The downwardly depending flanges are spaced away from the sidewalls of the tray to form gaps suitable for filling with a noncombustible granular substance, such as sand or crushed pumice stone. The cover channel additionally comprises at least one projection extending above the top segment and defining at least one burner port. The projection is preferably a longitudinal ridge defining a plurality of burner ports.

Because of the availability and comparatively low cost of gaseous hydrocarbon fuels, such as natural gas, propane and butane, they have become widely used in the United States. For example, they are commonly used to fuel appliances such as fireplaces, furnaces, water heaters, stoves, and ovens. Natural-gas, which is composed primarily of methane with small amounts of various heavier gaseous hydrocarbons, is particularly advantageous within the home.
Fuel efficiency is of course an important consideration in the design and operation of any gas fired appliance. By maintaining efficient combustion, heat output is maximized and the production of undesirable and potentially hazardous by-products of combustion, such as carbon monoxide, is minimized. It is well known that complete and efficient combustion of gaseous hydrocarbon fuels is achieved through the use of a relatively small, blue-colored flame. The use of this type of flame is not a significant problem in the design of most gas fired appliances.
However, flame appearance is a major consideration in the design of fireplaces fueled by gaseous hydrocarbon fuels. In such fireplaces, it is desirable to simulate as accurately as possible the flickering, multicolored flame normally produced by a natural log fire. The natural flame is of course very different from the uniform, blue-colored flame which produces complete and efficient combustion. Thus, in the design and operation of hydrocarbon gas fueled fireplaces, a tradeoff exists between efficient combustion on the one hand and a natural looking log fire on the other.
The prior art discloses several approaches that have been taken in the design of gas burner assemblies for fireplaces intended to have a natural looking appearance. One general approach is exemplified by U.S. Pat. No. 344,808 issued in 1886 to Bradberry; U.S. Pat. No. 4,838,240 issued in 1989 to Rieger; and U.S. Pat. No. 4,890,601 issued in 1990 to Potter. These patents disclose the use of what is known in the art as a "sand pan burner." In this type of burner, the gas output ports are buried beneath the surface of a granular, noncombustible substance, such as sand or crushed pumice stone. The gas exiting the burner ports is dispersed as it flows upwardly through the granular substance, and it ignites when it mixes with oxygen in the atmosphere surrounding the burner. The result is a flame pattern which is dispersed along the upper surface of the granular material. In addition, one or more artificial logs may be placed directly on the surface of the granular substance and at other locations within the surrounding firebox to produce a simulated log fire in which the logs are resting on a bed of sand. Furthermore, because of their relatively simple design, gas burners of the sand pan variety are generally inexpensive to manufacture and maintain.
Unfortunately, while sand pan burners produce relatively natural looking fires, they also tend to produce incomplete combustion and poor fuel efficiency. Since the hydrocarbon gas must be forced to flow through the sand or other granular substance, a relatively high back pressure develops which prevents the addition of air (known as "primary air") to the gas in the supply line. Therefore, all of the oxygen for combustion must be supplied from air in the immediate vicinity of the flame (known as "secondary air"). The supply of secondary air is often insufficient to allow for complete combustion. In addition, the flame of a sand pan burner cannot be easily controlled, and often comes into contact with the granular substance or other objects within the firebox. That contact reduces the flame temperature and hampers the combustion process.
As a result of the incomplete combustion, sand pan burners tend to produce unacceptably high levels of carbon (in the form of soot) and carbon monoxide. Emission and Safety Standard Z-21.50 of the American National Standards Institute ("ANSI"), which has been adopted by the American Gas Institute ("AGI"), sets a maximum emission level of 400 parts per million of carbon and carbon monoxide when burning natural gas. It is common for conventional sand pan burners to produce carbon and carbon monoxide at levels very near this limit. Thus, due to high carbon and carbon monoxide emissions, conventional sand pan burners have significant disadvantages when used in a home fireplace.
Another approach in the design of gas burner assemblies is exemplified by U.S. Pat. No. 4,930,490 issued in 1990 to Allan; U.S. Pat. No. 4,940,407 issued in 1990 to Rehberg et al.; U.S. Pat. No. 5,000,162 issued in 1991 to Shimek et al.; and U.S. Pat. No. 5,052,370 issued in 1991 to Karabin. Gas fireplaces of this general approach typically utilize a relatively complex grate structure to position artificial logs so that the unnatural looking, blue-colored flame is largely hidden from view. They also typically utilize complex burner designs having numerous individual parts. Fireplaces of this general type offer the advantage of high fuel efficiency and high heat output with a minimal production of undesirable by-products. Because of their complex design, however, they are often very expensive to manufacture and difficult to maintain.
A need therefore exists for an inexpensive and easily maintained gas burner assembly which can be used to produce a natural looking simulated log fire and which maximizes heat output while avoiding the production of excessive amounts of carbon and carbon monoxide due to incomplete combustion.

Gas burner assembly for simulating a natural log fire


The present invention relates to a level gauge, and more particularly, to a level gauge provided on a device such as an engine or transmission of a vehicle to discharge aft from the device and prevent a foreign substance from being introduced therein. In addition, the level gauge and an oil net can be integrated into a single module, to thereby save costs.

In general, a mechanical device such as an engine or a transmission of a machine (hereinafter, referred to as "vehicle") such as an automobile or a construction machine requires that oil should be supplied to a sliding part in order to perform a smooth operation of an operating part and maintain the lifespan of the operating part for a long period of time.
Viscosity and lubrication properties of the oil supplied to the engine of a vehicle are deteriorated over time due to oxidation by the contact between the oil and the air, abrasion of the sliding part, or the mixture of the oil and impurities introduced into the engine from the outside. Thus, a driver or an operator must check the state of the oil periodically to exchange the oil at the appropriate times.
FIG. 1 is a view showing the installation state of a conventional level gauge in accordance with the prior art, and FIG. 2 is a view showing the configuration of a conventional level gauge in accordance with the prior art.
Referring to FIGS. 1 and 2, the conventional level gauge includes a pipe (hereinafter, referred to as "tube") 30 made of a metal material that is mounted on a swing decelerator 10 of a vehicle and a gauge part 50 that is accommmodatably joined to the tube to measure the level of oil.
The gauge part 50 includes a hand grip 53, a sealing member 55, and an inspection part 57.
The hand grip 53 refers to a part that is gripped by an inspector's hand so that the inspector separates the gauge part 50 from the tube 30 to check the state of oil or couples the gauge part 50 to the tube 30. The sealing member 55 refers to an element that allows the gauge part 50 to be securely fixed to the tube 30 and simultaneously hermetically seals the tube 30. The inspection part 57 refers to an element that longitudinally extends inside an oil tank and allows for collection of an oil sample needed to check the state of the oil contained in the oil tank
In the above configuration, the inspector pulls up the hand grip 53 to separate the gauge part 50 from the tube 30, and then identifies the state of the oil sample collected at a lower end of the inspection part 57 so that the inspector can check the state of the oil contained in the oil tank.
The gauge part 50 has concavo-convexes 56 formed on the outer circumferential surface of the sealing member 55 and the sealing member 55 is insertingly fitted into an upper end of the tube 30 in a press-fit manner.
However, the conventional level gauge entails a problem in that since the sealing member 55 is press-fittingly coupled to the tube, air inside the decelerator 10 is not easily discharged to the outside. In addition, the air inside the decelerator is expanded over time by heat generated in the operation process of the engine to cause the internal pressure of the engine to be increased, resulting in damage of a packing member or deterioration of operating efficiency of the machine.
Conventionally, in an attempt to solve such a problem, a discharge groove (not shown) is formed on the outer circumferential surface of the sealing member 55 in juxtaposition with the inner circumferential surface of the tube 30 so as to discharge the air heated to the outside through the discharge groove. However, such a conventional level gauge still encounters a problem in that foreign substances or moisture is introduced into the oil tank from the outside, resulting in deterioration of the quality of the oil and reduction of the lifespan of the machine.


A system for transferring data includes structure (i.e, hardware, software, a combination thereof) for requesting data from a second bus, which data is destined for a first bus; and structure for gaining ownership of the second bus for the purpose of transferring the data from the second bus to the first bus, which structure includes substructure for waiting a programmably variable amount of time to see if additional data is requested by the first bus, before relinquishing control of the second bus.

1. Field of the Invention
The present invention relates to apparatus and methods for transferring data between devices in a computer system. More particularly, the present invention relates to apparatus and methods for maintaining a data stream between devices that handle data differently.
2. Description of the Related Art
In computer systems, there frequently arises a need to transfer data efficiently between devices. Meeting this need may be complicated by various factors.
One complicating factor may be use of different formats--e.g., big-endian versus little-endian--for ordering data. In computer systems where the central processing unit is an Intel 80.times.86 processor, the data format used is typically the little-endian format. Nonetheless, peripheral devices which are based on the big-endian format are sometimes used in the 80.times.86-processor-based computer systems. To function properly, there must be "bridging" circuitry capable of performing little-endian/big-endian data format conversion.
Another complicating factor may be different data handling speeds. It is, for example, difficult to efficiently stream data from a bus in which data is moving at a first speed, to a bus on which data moves at a second, different speed.
Yet another complicating factor may be difficulties that arise in respecting continuity of data. For example, if the total length of an intended transfer of data is unknown; for example, in a case where data is sent in bursts on the one hand, and transferred in a clocked stream on the other; it is difficult to systematically detect and maintain contiguous blocks of data.
Complicating factors such as those set forth above have hampered efforts to design perfectly efficient apparatus and methods for transferring data between devices in computer systems. At the same time, development of devices that reflect improvements in data handling, and that have an associated end to be coupled to preexisting devices, has created many situations in which improved data transfer schemes would be helpful. A prime example of this has arisen in the Fibre Channel/computer interface arena. In that interface it is necessary to bridge data between a Peripheral Component Interconnect ("PCI") bus and a Tachyon System Interface ("TSI") bus. Towards this end, Hewlett Packard has published a "Tachyon TSI to PCI Bus Gasket Application Note," ver. 1.0, the express purpose of which is "to present an intermediate discrete solution to interface Hewlett-Packard's Tachyon Fibre Channel Controller to a standard version 2.0 compliant PCI bus." This application note prescribes a three chip solution, presented with the statement that "t!he interface is not intended to be an end-all solution but is intended to be a starting point for developing a fibre channel solution that includes Tachyon." Thus, it is clear that even Hewlett-Packard itself, the manufacturer of the Tachyon Fibre Channel controller, recognizes the need for, but is not yet satisfied with, TSI/PCI bridges. Bridging TSI and PCI buses requires providing a solution to all three complicating factors mentioned above, that is, data format conversion, speed conversion, and recognition of continuous or contiguous data so that bandwidth can be used efficiently. Although, frankly, several good solutions have been proposed for the big-endian/little-endian conversion requirement, good solutions have not yet been developed for the "speed" and "recognition" problems mentioned above.
In light of the foregoing it is a shortcoming and deficiency of the prior art that there has not heretofore been developed apparatus and methods especially well suited for efficiently bridging certain buses, such as the PCI and TSI buses, especially insofar as speed conversion and respect for continuity of data are important components of such apparatus and methods.

Apparatus and method for combining data streams with programmable wait states


Hydrazino, oxyamino and carbonyl-based reagents and methods for incorporation into oligonucleotides during their solid phase synthesis are provided. Modified oligonucleotides are provided that incorporate the reagents provided here in. Immobilized oligonucleotides and oligonucleotide conjugates that contain covalent hydrazone or oxime linkages are provided. Methods for preparation of surface bound oligonucleotides are provided. Methods for the preparation of oligonucleotide conjugates are also provided.

Oligonucleotides functionalized 3′, 5′ or internally with reactive moieties have been used for a variety of therapeutic and diagnostic purposes. For example, modified oligonucleotides incorporating targeting moieties have been prepared to increase activity of antisense oligonucleotides for therapy. Functionalized or modified oligonucleotides have been prepared to permit conjugation to supports and also for preparation of conjugates.
Methods have been described for achieving these purposes, but in many cases these methods have inherent disadvantages and do not satisfy all the criteria required by currently developing technologies. Methods in which a functional moiety can be incorporated into an oligonucleotide during its synthesis on a solid support are limited.
There is a need to develop methods to site-specifically bind oligonucleotides to surfaces for a variety of purposes, such as for identification of genes for pharmacogenomic, diagnostic and therapeutic purposes.
Functional groups that can be added directly to a growing oligonucleotide on a solid support include amines and thiols. Direct binding of amino or thiol-functionalized oligonucleotides to solid surfaces require that the surface be modified with a moiety that reacts directly with an amino or thiol function. The reactive moieties succinimidyl esters and maleimides have been used for this purpose. The coupling efficiency of these moieties suffers from their inherent instability and ease of hydrolysis (for maleimides and succinimidyl esters).
Biotin monomers that can be added to the 5′-end of an oligonucleotide on a solid support have been described, as well as coupling of biotinylated oligonucleotides to surfaces and other molecules that have been modified to incorporate either avidin or streptavidin protein. This method is functional but requires the use of a protein that is expensive, may lead to non-specific binding, and has at most four biotin binding sites per molecule. Also, incorporation of large molecules on biotin reduces the binding affinity and the number of accessible binding sites on avidin. The density of oligonucleotide per mm2 is limited due to the use of a protein having a molecular weight of about 14000.
These same limitations exist for the preparation of oligonucleotide conjugates. The incorporation of activated functionalities, such as succinimidyl esters or maleimides, of the conjugation partner (compound to be conjugated to the oligonucleotide) can be costly, and not even possible in some instances.
Table 1 below lists the available reactive couples to bind oligonucleotides to solid surfaces.
TABLE 15′-oligonucl otideSurfacemodificationmodificationaminoN-hydroxysuccinimidyl ester(NHS), isothiocyanates (ITC)thiolMaleimide, bromoacetyl, activatedthiol (to form disulfide)disulfidethiolbiotinavidin
Due to the limitations of available methods, there is a need for efficient crosslinking agents for immobilization of oligonucleotides on solid surfaces, and for preparation of biopolymer conjugates.
Therefore, it is an object herein to provide reagents and methods for immobilization of oligonucleotides on solid surfaces without the need for post-synthetic modification of the oligonucleotide. It is also an object herein to provide reagents and methods for synthesis of biopolymer conjugates, including oligonucleotide, protein, oligosaccharide, glycoprotein and/or protein nucleic acid (PNA) conjugates. A further object herein is to provide modified, immobilized or conjugated oligonucleotides.

Functional biopolymer modification reagents and uses thereof


A tape cartridge in which it is possible to suppress warping otherwise produced in a lower cartridge half in its entirety on insert molding a meal plate on the lower cartridge half. A reel lock unit 21 having a reel lock member 37 and a mistaken recording inhibiting member 39 is mounted on a backside outer peripheral wall section 16. Formed adjacent to the corners intermediate between the reel lock unit 21 and the corners are cut-outs 16C, 16D in the outer peripheral wall section 16. The cut-outs 16C, 16D are of cut-out depths coincident with the boundary line of a label area L bonded on the backside of the main cartridge body portion 2.

1. Field of the Invention
This invention relates to a tape cartridge in which a pair of tape reels each having wound thereon a tape-shaped medium such as a magnetic tape are housed within the inside of a man cartridge body portion and in which a metallic plate is insert-molded on a lower cartridge half constituting the main cartridge body portion.
2. Description of the Related Art
In general, in a conventional tape cartridge for a video tape recorder or DAT, a main cartridge body portion is formed by a lower cartridge half and an upper cartridge half each in the form of a shallow rectangular saucer opened on its front side. Within this main cartridge body portion are rotatably housed a pair of tape reels having wound thereon a magnetic tape, while a loading spacing is defined on the open front side. When the tape cartridge is loaded on a loading unit of a recording/reproducing apparatus, tape loading means provided on the recording/reproducing apparatus is intruded into this loading spacing. This loading spacing is opened or closed by a lid rotatably supported by the main cartridge body portion.
Meanwhile, such tape cartridge is known in which a metallic base plate is insert-molded in unison on a bottom surface of a lower cartridge half constituting the main cartridge body portion. This tape cartridge, having the base plate, is improved in mechanical strength against warping or torsion, while being increased in overall weight. If vibrations of a tape driving mechanism driving tape reels are applied to the tape cartridge, there is no risk of the tape cartridge being oscillated to affect the running of the magnetic tape, thus assuring high-precision recording/reproduction of information signals.
In a lower cartridge half 104, making up the tape cartridge, shown in FIG. 1A, a base plate 106 may be deemed to be substantially rigid with respect to a resin material when the lower cartridge half is thermally contracted following injection molding, so that the amount of contraction of the portion of a resin part 116 neighboring to the base plate 106 is substantially zero. On the other hand, the portion of the resin part 116 remote from the base plate 106 is contracted significantly, on thermal contraction following injection molding, as compared to the portion thereof neighboring the base plate 106.
That is, when the base plate 106 is insert-molded on the lower cartridge half 104, the portion of the lower cartridge half neighboring to the base plate 106 undergoes only small contraction, while the portion thereof remote from the base plate 106 undergoes significant contraction. The result is that the lower cartridge half 104 is subjected to tension in the longitudinal direction of the outer peripheral wall section due to such differential contraction as indicated by arrow in FIG. 2A. Thus the lower cartridge half 104 undergoes warping in its entirety as indicated in FIG. 2B. Such warping in the entire cartridge half is produced significantly in particular in the longitudinal direction of the lower cartridge half 104.


Implementations generally relate to color corrections to photos. In some implementations, a method includes determining a face profile from a plurality of photos of a face. The method further includes receiving a target photo of the face. The method further includes matching the face in the target photo with the face in the plurality of photos. The method further includes performing one or more color adjustments to the face in the target photo based on the face profile.

The popularity and convenience of digital cameras as well as the widespread of use of Internet communications have caused user-produced images such as photographs to become ubiquitous. Image editing systems for various consumer electronic devices and personal computers enable a user to manipulate images. Digital cameras typically apply a white balance correction to photos, which is often inaccurate. Users can manually correct the white balance correction if the digital camera correction is inaccurate.


An apparatus for diverting wastewater in septic system comprises a top, a side adjoining and extending downwardly from the top, the top and the side form an inner volume and a partially open bottom. The bottom can be fully open. A first opening extends upwardly from the partially open bottom. A second opening, having a perimeter, is also on the side. The apparatus can be placed at outlet end of a trench to receive the trench pipe. The first opening, the open bottom and the inner volume permit the apparatus to be placed over a pipe without adjustments or modifications.

A well designed septic system will meet several basic requirements. First, the system will effectively collect, treat and transport wastewater throughout a drainfield. Second, the septic system will be simple to install and its components designed to reduce or eliminate installer error. Finally, a septic system will be easy to maintain. Poor design, improper installation and inadequate maintenance contribute to, or cause, poor drainage, blockages, or inefficient treatment of waste from a dwelling. Properly designed septic systems therefore integrate required performance attributes (i.e. collection, treatment and distribution of waste) with easy installation and a mechanism to simplify maintenance.
Several attempts have been made to accomplish such an integration. Particular attention has been given to the distribution of wastewater over a drainfield. Two systems that are available to distribute wastewater over a drainfield are equal distribution and serial distribution. An equal distribution system equally divides wastewater from a septic tank through a distribution box to several absorption trenches located in the drainfield. In a serial distribution system, wastewater travels through a series of linked absorption trenches in a sequential manner. Serial distribution systems are often used where the elevation of a septic tank is higher than the drainfield. Because wastewater travels sequentially through a serial distribution system, the linkages between two given trenches are important to the efficient operation of the septic system.
Conventional approaches linking two subsequent trenches in a serial distribution system are "step-down" and "drop-boxes." The step-down can have three parts: an inlet, an elbow junction and a discharge arranged so that the elbow junction is elevated higher in the trench than either the inlet or discharge. This arrangement requires an upward incline leading up to the elbow junction of the step-down. In normal operation of step-down wastewater can accumulate in a trench pipe and flow upwards through the inlet, over the elbow junction, and through the discharge towards the next trench. When a step-down is improperly installed, or when the inlet and/or the elbow junction contains blockage, wastewater can flow backwards in the trench pipe causing undesirable backfill. A step-down is a closed system requiring precise linkages between the inlet, elbow junction and discharge. A "drop-box" can be a closed structure with an access lid, an inlet, outlets positioned close to the bottom of the drop-box, and an overflow outlet positioned close to the top. Wastewater enters the drop box and, after wastewater accumulates to rise to the height of the overflow outlets, is distributed to one or several subsequent trenches. Step-downs typically are constructed at the septic site, making proper installation imperative.
If installed improperly, both the step-down and drop-box can lead to malfunctions in the subsequent trenches. For step-downs, the possibility exists that the elbow junction will not properly accommodate for elevation changes between the two trenches. Less than precise measuring, cutting and fitting can lead to blockages and possible back-fill. When this occurs, the land owner or installer may incur substantial repair or replacements costs. Drop-boxes are typically prefabricated prior to installation and can unfortunately be easily installed backwards. For example, a pipe from a septic tank can be accidentally inserted into the overflow outlet of the drop-box. When water has accumulated the trenches, the wastewater will exit the overflow outlet first and causing undesirable backfill into the septic tank. Thus, improperly installed drop-boxes lead to back fill and blockages thus inhibiting the discharge of wastewater from the septic tank. Even when properly installed, both step-down and drop-box systems are subject to fatigue and excessive loads leading to ruptures or breaks. These breaks may disrupt wastewater flow and the delicate balance of a septic system. These attempts have failed to serve the primary goals of septic tank systems, i.e., to efficiently collect, treat and dispose of wastewater and to provided ease of maintenance and repair. The invention, however, efficiently collects and distributes wastewater in a septic system and can replace the step-down and drop-boxes currently used.


A biomechanically adapted dual direction sportsboard. This stance-specific sportsboard accommodates a rider's stance, whether they are a “regular-foot” or a “goofy-foot.” This stance-accommodating dual direction sportsboard allows the rider much greater control since the board accommodates the specific biomechanics of the rider's dominant stance, whether their preference is to ride with their left foot in front or their right foot in front. The dual direction sportsboard has rails which are offset from each other, which allows for a rider with fixed foot positions to significantly change the trim of the board by shifting from heel-side rail to toe-side rail or back to heel-side rail. This provides the rider much greater control over the board while performing surfing-style maneuvers, especially with the board attached to their feet. Additionally, for kiteboarding, the offset rails allow for greater windward ability than with legacy designs.

When riding a sportsboard, riders need to shift the force of their weight to make different maneuvers. They need to lean forward at times, and lean back at times. They also need to engage the rails of the boards, because that is how a sportsboard is turned at speed. The rails are the outer edges of the board that run longitudinally. For example, to execute a toe-side carve maneuver on the toe-side rail of the board, and to fully engage the rail the rider must lean forward and over the toes of their forward foot, thereby transmitting the force of their weight onto the half of the board and its rail that is ahead of the forward or front foot and toes of the rider. This maneuver is akin to a "bottom turn" that a surfer makes on a wave.
Conversely when a rider wants to transition from a "bottom turn maneuver" to a "cutback maneuver," thereby executing a heel-side carve maneuver, the rider must lean back and transmit the force of their weight onto the heel-side rail and the half of the board that is behind the heel of the back foot. This maneuver is akin to a "cutback" that a surfer makes on a wave.
Legacy sportsboards, whether they are "directional boards," where the nose section is distinct from the tail section, as with surfboards, or with "dual direction boards," where the board is designed to be ridden in either direction wherein which end is the nose and which end is the tail is then determined by which direction the board is traveling. Unfortunately, these legacy sportsboards make no accommodation for the dominant stance of a rider; whether they are a left-foot-forward rider or a "regular-foot," or a right-foot-forward rider or a "goofy-foot." What is needed is a sportsboard design that accommodates the differing dominant stances of either a "regular-foot" or a "goofy-foot" rider, and thereby provides significantly greater control when the rider is executing the aforementioned maneuvers.
Moreover, these legacy approaches introduce yet additional problems to be solved. The design constraints inherent in the shaping of symmetrical legacy boards have been further reinforced because surfboard and sportsboard designers ("shapers") have been slavishly tied to a long history of symmetry in design for two reasons: 1) a need to conform their designs to work equally well for regular-foot riders as for a goofy-foot riders; and 2) amongst the relatively small and elite profession of surfboard shapers who still shape by hand, it has been, and still currently is, a matter of professional pride to shape a symmetrical board; since a lack of symmetry is indicative of a lack of shaping ability.
Additionally, shapers have worked to create surfboards adapted to different types of waves, and to different surfing styles. However, almost all legacy surfboard designs, and all legacy dual direction sportsboard designs, are constrained by the need to compromise under the mandates of symmetry.
Moreover, the fairly recent introduction of computer aided design and correlative computer-controlled milling machines to the profession of sportsboard shaping has exacerbated the legacy problem of reinforcing symmetry in sportsboard shaping. This is because precise computer controlled milling machines are replacing fallible human hands, and computers create precisely symmetrical shapes.
This further creates the additional problem to be solved, in that the increasingly ubiquitous use of these machines and computer aided designs has begun to replace the innate human creativity that flows from the hands of a shaper. Especially for the shaper who rides the sportsboards which he is sculpting, with the direct understanding of how the board will perform under circumstances that he has experienced; and through this experience has acquired the tactile knowledge of what works and what doesn't.
What is needed is a revolutionary design approach that breaks away from the long-held constraints and inherent limitations of symmetry. What is needed is a design approach which provides a framework within which a shaper may design a sportsboard that is more closely tailored to the biomechanical needs of the individual rider, thereby providing the rider with much greater control.
Additionally, a new problem in the sport of kiteboarding has emerged that is also in need of a solution. This is the need for greater control over a kiteboard while rapidly accelerating and carving through a turn. This new technique, developed by this author and coined by this author as "power looping," cannot be solved by legacy approaches.
Power looping is a method whereby a kiteboarder may generate tremendous power when transitioning from one direction to the other by creating a radical increase in the speed of the flow of "apparent wind" over the kite's surface. Apparent wind, as opposed to "true wind," is the wind that is created by an object's relative movement through the true wind. True wind is the actual, unadulterated speed of the wind over a relatively stationary surface area.
The application of apparent wind is now commonly demonstrated by very fast sailing craft like windsurfers, fast multihulls, hydrofoils and iceboats. Apparent wind enables high-speed wind driven vehicles to achieve much greater speeds than what speed the true wind is blowing.
Additionally, what makes the use of a traction kite unique among all other sailing craft, including the aforementioned high-speed sailing craft, is that the motive force of the kite is separate from the vehicle being moved, since the kite is actively being flown on lines. Thus, traction kites allow for much great power generation, even when the person flying the kite is stationary. This is because the power of the kite is directly related to the speed of the apparent wind that is crossing the airfoil or kite canopy. An easy way to understand this principle is to visualize a large propeller, and then visualize the kite as the surface near the tip of the propeller. Thus, the center of the propeller may remain relatively stationary while the propeller tip generates force.
An important additional consideration is that the ratio of the increase of wind-force to wind-speed, is exponential and not linear. Thus, a wind of twenty knots generates considerably greater force than merely twice the force of a breeze of ten knots. Additionally, a traction kite can go from a stationary position directly above the kiteboarder to a tremendous speed in a matter of a moment, especially when it is accelerated by gravity.
Another principle to understand is that a traction kite can only be flown within a "wind window" which is the half-sphere area within which a traction kite can be flown (e.g. see FIGS. 15 and 16). The size of a given wind window is determined by the length of the flying lines. The "power zone" is a zone that is horizontal to the water and along the base of the half-sphere of the wind window that is downwind from the kiteboarder. When the traction kite is flown across the power zone, the kite is close to perpendicular from the kiteboarder, and thus at an angle of about ten degrees off the surface. Most kiteboarders fly their kites at about a forty-five-degree angle, to avoid the power zone which otherwise puts the kite perpendicular to the force of the wind, and thus allows the full spread of the kite's canopy to generate force.
The traditional legacy method of performing a kiteboarding transition, when a kiteboarder jibes from one tack to the other, is done by flying the kite upwards and then in the opposite direction (e.g. FIG. 15). Since most kiteboarders generally fly their traction kites at about a forty-five-degree angle, the kite is already relatively high in the air, but gravity will slow the kite down and provide for a slower speed in the transition.
However, to perform a power loop: instead of flying the kite up and then overhead against the slowing forces of gravity (e.g. FIG. 16), the kiteboarder swoops the kite from on high towards the water's surface, thereby rapidly accelerating the kite and creating an exponential increase in apparent wind force; and then, just before impact, the kiteboarder pivots the kite to fly horizontally across the "wind window" and through the power zone from one side of the wind window to the other (e.g. FIG. 16), while at the same time performing a carving turn on the rail of the kiteboard.
Another way to perform a power loop can be done by flying the kite more horizontally across the water, and then instead of just using the control bar to steer the kite, the author grasps one of the steering lines near the bar with one hand and pulls on the line, which makes the kite rapidly pivot before it shoots across the wind window through the power zone. Grasping the lines like this is considered heretical to most kiteboarders. However, this technique allows the author to actually control the pivot speed of the kite and momentarily also decrease its power by reducing the speed of the apparent wind that is flowing across the canopy, before the tremendous surge of power that comes from flying the kite across the power zone. This momentary decrease in power is accomplished when the directional flow of the apparent wind across the canopy is interrupted when the kite is pivoted on its own axis.
Of additional consideration while power looping is that the forward movement of the rider adds to the apparent wind that is generated as the rider swoops the kite forward and towards the water. This is the opposite of what occurs when a rider performs a traditional transition wherein the kite is flown upwards and away from the direction of travel.
To emphasize the tremendous power generated by "power looping," the movement and power of the kite can be compared to what is commonly known in kiteboarding as an accidental "death looping." Death looping occurs when a kiteboarder loses control over their traction kite and the kite loops uncontrollably through the air while dragging the unfortunate kiteboarder behind it. The name "death loop" is well deserved, because quite a few kiteboarders have lost their lives because their kites were death looping while they failed to release the kite before it dragged them into an immovable object.
In sum, what is needed for aggressive carving and especially for the new technique of power looping is a dual directional sportsboard that offers greater control than what the legacy designs provide.


A method of a transceiver arranged to operate according to a Radio Access Technology, RAT, in a cellular communication system is disclosed. The method comprises determining (100) a position value for the transceiver; accessing (104) a database based on the determined position value, wherein a transceiver parameter set corresponding to the position value is acquired, wherein the transceiver parameter set is arranged to adapt operation of the transceiver for the determined position within the RAT; and applying (106) settings of the transceiver according to the acquired transceiver parameter set. A transceiver and a computer program are also disclosed.

The increase of traffic in cellular communication systems the last few years very much relates to mobile internet and mobile broadband. The traffic increase in turn makes it important to optimize the capacity and performance in the cellular network. Therefore a throughput and connection robustness has increased in importance also for transceivers of the cellular network, since optimized radio performance will not only be a benefit for the end user but also for the operator which by better transceiver performance can improve the spectral efficiency and hence also the capacity in the network.
Cellular communication systems like HSPA and LTE is and will be deployed by hundreds of operators all over the world, all operating in different radio environments. From a terminal point of view, a transceiver parameter settings, like selectivity filter coefficients, Radio Resource Management filter parameters, etc, optimized for, say operator A, will typically not optimize the performance for operator B, or even for operator A in another region/country or geographical position. WO 2010/062630 discloses an approach for acquiring information of a suitable Radio Access Technology (RAT) to use for a certain position, and information on certain settings specific for the advised RAT. A typical traditional solution is to use parameter settings that are a trade off, implying good but not optimized performance for most scenarios. Updates of parameter settings are then typically made only on event basis, for instance when a certain problem have occurred in a certain area for a certain operator. Then a retuning of parameters are made, which may solve/optimise the performance for that specific area/operator. However this typically will worsen the performance in another area.
Therefore there is a need for an approach for optimised radio performance regardless of operator and/or geographical position.

Method of adapting the parameter set of a mobile terminal transceiver based upon its geographical position


A pillbox loading device receives a pillbox and has a top opening alignable with the pillbox compartments. Channels extend from the top opening and define funnels that guide the pills into the pillbox.

Pillboxes are multi-compartment containers having lids or tops that individually open and close the compartments. Pills are placed in the open compartments and the compartments are then closed. When it is time to take a pill, a compartment is opened and the pill is removed for use.
Pillboxes are normally designed to hold pills sufficient for some specific dosage regimen. The pillbox compartments are typically arranged to extend side-by-side along the length of the pillbox, with the number of compartments based on the frequency the pills are to be taken. One common pillbox, for example, has seven transparent compartments labeled to identify each day of the week and are intended to store a week's worth of pills separated by day of the week. Another common pillbox has four transparent compartments labeled to identify different parts of the day—for example, morning, noon, evening, bedtime—and are intended to store a day's worth of pills that are taken at different times of the day.
A user knows whether or not he or she has taken a pill for that day of the week or time of day by simply looking to see whether or not that day's compartment contains pills.
Some pillbox users have physical limitations that makes it difficult for them to place pills into the open compartments of a pillbox. There is a need for a pillbox loading device that allows for easier loading of pillboxes.


A photochemical reactor system employing an optical fibers in the form of a cable to transmit light to solid-supported TiO.sub.2 -containing photocatalyst is disclosed. Light energy is transmitted to TiO.sub.2 -containing particles, chemically anchored onto one or more quartz fiber cores, via radial refraction of light out of each fiber. TiO.sub.2 -containing coating layer minimizes the interfacial surface area of the quartz core and TiO.sub.2 -containing particles and operation with incident irradiation angles near 90.degree. enhance light propagation along the fibers. A maximum quantum efficiency of .phi.=1.1% for the oxidation of 4-chlorophenol was achieved. Fiber efficiency permits the light source to be separated from the photocatalyst.

Heterogeneous photocatalysis on metal oxide semiconductor particles has been shown to be an effective means of removing organic and inorganic pollutants from water and air streams. The effects of photocatalyst composition, structure, crystal size, band gap energy, incident light intensity, and the nature of the electron donors and acceptors on photocatalytic reactivity have been investigated.
Photochemically-excited semiconductor particles can catalyze the reduction and/or oxidation of a variety of chemical species. Charge-pair generation is achieved by the absorption of a photon with an energy greater than or equal to its band gap energy. The absorbed photon promotes an electron from the valence band into the conduction band, and in doing so, creates a positively charged valence band hole. Excited-state electrons and holes can either: (i) recombine with the release of heat; (ii) migrate through the lattice structure to various trapped sites; or (iii) migrate to the particle surface and participate in electron transfer reactions as reported by Hoffmann, et al., Chem. Rev., 1995, 95, 69. Surface-trapped conduction band electrons can reduce surface-bound oxidants (+0.5 V to -1.5 V vs NHE depending on the semiconductor and pH), while valence-band holes are capable of oxidizing a wide range of electron donors (+1.0 V to +3.5 V vs NHE).
Hydroxyl radicals, formed from the oxidation of vicinal water or bound hydroxyl groups, are generally believed to be the principal reactive species responsible for the photo-oxidation of organic compounds in semiconductor photocatalysis. In some cases, direct hole transfer (h.sup.+.sub.vb) via a photo-Kolbe mechanism has also been shown to be an important oxidation pathway. Surface-bound OH.circle-solid. radicals are produced by the oxidation of titanol groups by valence band holes as follows: EQU >Ti(IV)OH+h.sub.vb.sup.+ .fwdarw.>Ti(IV)OH.sup..circle-solid.+( 1)
Direct electron transfer (i.e., hole transfer) may occur as follows: ##STR1##
Charge neutrality of the particle is maintained by concurrent reduction via conduction band electrons. In an aerated system, oxygen is reduced and forms superoxide and/or hydroperoxyl radicals. These species can be further reduced to form hydroxyl radicals. EQU >Ti(IV)OH.sub.2.sup.+ +O.sub.2 .revreaction.>Ti(IV)OH.sub.2.sup.+ . . . O=O(3) EQU >Ti(IV)OH.sub.2.sup.+ . . . O=O+e.sub.cb.sup.- .fwdarw.>Ti(III)OH.sub.2 . . . O=O (4) EQU >Ti(III)OH.sub.2 . . . O=O.fwdarw.>Ti(IV)OH.sub.2.sup.+ . . . O-O.sup..circle-solid.- ( 5)
In addition to oxygen, other species present in the liquid phase (e.g., CCl.sub.4) may be reduced if the reduction potential of the species is more positive than the conduction band energy.
Practical application of metal oxide semiconductors as photocatalysts often requires immobilization of the photocatalyst in a fixed-bed reactor configuration that allows the continuous use of the photocatalyst for treating aqueous or gaseous effluent streams by eliminating the need for post-process filtration. In conventional fixed-bed reactors, the photocatalyst is coated on the walls of the reactor, on a support matrix, or around a casing containing the light source. However, these configurations present several drawbacks such as low light utilization efficiencies due to absorption and scattering of the light by the reaction medium and restricted processing capacities due to mass transport limitations. A novel approach to solving these problems employing optical fibers as a means of light transmission and distribution to solid-supported photocatalysts was first proposed by Ollis and Marinangeli in their papers, AIChE J., 1977, 23, 415 and AIChE J., 1980, 26, 1000. However, they predicted that photocatalytic optical fiber reactor systems would not be practical due to catalyst deactivation caused by heat buildup in a bundled array. Hofstadler, et al. in their paper reported at Environ. Sci. Tech., 1994, 28, 670, have shown recently that TiO.sub.2 -coated quartz fiber rods fixed in a tubular reactor configuration using a light source adjacent to the reactor can be used to carry out oxidation of 4-chlorophenol. They reported effective quantum yields of 0.0002. In a 1991 masters thesis by D. C. Gapen, "Photocatalytic Degradation of Chlorinated Hydrocarbons", Univ. of Wis., use of an optical fiber cable reactor (hereinafter "FOCR") for photocatalytic oxidation was investigated. Problems with delamination of the TiO.sub.2 coating resulted in partial degradation of 3-chlorosalicylic acid. However, a maximum quantum efficiency of 0.069 for the partial photolytic and photocatalytic oxidation of 3-chlorosalicylic acid was estimated.
Optical fibers in an FOCR can be treated as elementary waveguides having a core with an outer reactive layer. In this case, light in the form of a plane wave propagating in the core medium (designated by the subscript "1") having a refractive index n.sub.1, and which is incident on an interface with the outer medium (designated by the subscript "2") having a refractive index n.sub.2, is partially reflected and partially refracted. Snell's Law states that the ratio of the sine of the wave's incident angle, .theta..sub.i, and the sine of the wave's refracted angle, .theta..sub.refr, is constant. This ratio is equal to the ratio of the wave's velocities in the respective mediums and the inverse ratio of the refractive indices according to the formula, ##EQU1##
For fibers in which n.sub.1 is higher than n.sub.2, the propagating wave will be reflected within the fiber with 100% efficiency when the angle of incidence exceeds the critical angle. This critical angle, .theta..sub.c, is defined as the arcsine of the ratio of the refractive indices of the core and outer mediums. Some refraction will occur if the angle of incidence is less than the critical angle. However, if n.sub.1, is less than n.sub.1, then refraction will occur for all incident angles.
If the interface of the core and outer mediums absorbs the incident light with an absorption coefficient .alpha., in units of inverse length, n.sub.2 is replaced with a complex refractive index, n.sub.2 : EQU n.sub.2 =n.sub.2 (1-.kappa..sub.2) (7)
The attenuation index, .kappa., is related to .alpha. by EQU n.kappa.=.alpha.c/4.pi.v (8)
where c and v are the velocities of the light wave in a vacuum and in the medium, respectively.
For all wavelengths, the index of refraction of a single TiO.sub.2 rutile crystal is greater than that for quartz, which is constant at about 1.4 (personal communication between the inventors and R. H. French of DuPont Co., 1994). Values for n for wavelengths that are not absorbed by TiO.sub.2 (.lambda.>375 nm) are constant at about 2.8. As the wavelength approaches the absorption onset of the photocatalyst, the index of refraction of the TiO.sub.2 crystal increases, reaching 5.5 at about 300 nm. Values for .kappa. similarly increase from 0 to about 1.5. As a consequence, incident light will be refracted to some degree for all incident angles. The ratio of the energy transmission to the TiO.sub.2 coating to the incident radiation at each reflection depends on the incident angle, the wavelength, and the refractive indices according to the Fresnel equations: ##EQU2## where E.sub.r and E.sub.i are the energies of the refracted and incident radiation, respectively, and the subscripts .perp. and // refer to the transverse electric and magnetic (TE and TM, respectively) polarizations of the incident light. The refraction for perpendicular polarizations monotonically decreases from a given value at normal incidence (0.degree.) to zero at the grazing angle, parallel to the quartz-coating interface. The refraction for parallel polarizations increases as the incident angle increases, reaching a maximum of 100% at Brewster's angle, (.theta..sub.B =tan.sup.-1 n.sub.1 /n.sub.2), and then falls sharply to zero as the incident angle approaches the grazing angle. The shapes of these curves are a function of the indices of refraction for quartz and the TiO.sub.2 particles (complex) and the extinction coefficient of the photocatalyst. Light incident upon a quartz-water or quartz-air interface, representative of a coating pore interface, will be totally internally reflected for incident angles greater than the corresponding critical angle with no refracted transmission of energy because the refractive index of the quartz core is greater than that of air and water. This assumption is an oversimplification of the system since the wavelength is probably at least an order of magnitude greater than the interfacial pore surface area. In this case, the interaction between the pore interface and the photon is a function of the "effective" refractive index of the pore interface. In the 1986 work by W. M. Bruno ("Powder Core Dielectric Wave Guides," Caltech Thesis, Pasadena, 1986) it has been postulated that for a powder material composed of particles, which are small compared to the incident wavelength, the refractive index of the material will be a statistical composite of the refractive indices of the particles and the void material (e.g., H.sub.2 O). In addition, the absorption of the material increases significantly as the packing fraction of the powder increases.

TiO.sub.2 -coated fiber optic cable reactor


An amplifier is driven by DC voltage from a switchmode power supply, whereby the switchmode power supply includes on the primary side a primary winding and bias supply winding. The bias supply winding supplies a reflected voltage from a secondary winding to a bias supply capacitor. The bias supply capacitor drives the control circuit and provides a sensing to the control circuit. The power supply further includes an active clamp circuit for controlling the voltage stress on a main switch. In another embodiment, boost inductors and a balancing transformer are added on the primary side of the transformer to prevent overvoltage conditions at light loads.

Amplifiers are used to increase the voltage and current levels of a signal in order to drive a load. All amplifiers use a power supply that supplies the energy required to perform this task. The power supply converts the AC line voltage into DC voltages suitable for the amplifier. The power supply also isolates the line voltage from the DC output voltages for safety purposes. This is accomplished by the transformer. A conventional power supply in an amplifier includes a transformer that works directly off the 60 Hz line voltage, and tends to be relatively heavy and bulky. The output of many prior art AC to DC power supplies completely unregulated, with no current limiting. In many prior such power supplies, the input current typically has a power factor of less than 0.7, not meeting most international regulations.
To resolve these problems, the use of switching power supplies was implemented. Now there was both line and load regulation, and current limiting. Power factor was still less that 0.7, and generally they could not work over the universal input voltage range of 90-265 VAC without some sort of adjustment. The supplies were implemented with voltage fed topologies such as the half bridge topology.
To remedy the switching supply problems, a boost PFC (power factor correction) stage was added to the input of the power supply. The boost stage consists of a boost inductor coupled to a boost switch. The boost stage can be controlled to yield a high power factor. The resulting supply is fully regulated, overload protected, and power factor can exceed 0.95, with a fully universal input voltage range. Unfortunately, the addition of the PFC stage reduces the efficiency of the supply. Additional circuitry is necessary to limit inrush current. It also became apparent that in many cases with audio amplifiers that the fully regulated output voltage did not sound as good as the unregulated output of the conventional supply. This may be partly due to the use of large energy storage capacitors being located in the transformer primary side of the power supply, with only small filtering capacitors on the output or secondary side. This limits the instantaneous current available to the amplifier. The added stage also increases the parts count and complexity of the design. The present invention resolves these detriments associated with known switchmode supplies while maintaining their advantages.


An uneven portion is formed on a substrate extending in a linear shape stripe pattern, convex portions of an insulating film that intersects with a crystalline semiconductor film divided into island shapes are removed, and an amorphous semiconductor film is formed on the insulating film. The semiconductor film is melted and flows into concave portions of the insulating film, where it crystallizes, and the semiconductor film that remains on the convex portions of the insulating film is removed. A semiconductor film divided into island shapes is then formed from the semiconductor film formed in the concave portions, the convex portions of the insulating film are removed in portions where channel forming regions are to be formed, thus exposing side surface portions of the semiconductor film. A gate insulating film and a gate electrode contacting the side surface portions and upper surface portions of the semiconductor film are then formed.

1. Field of the Invention
The present invention relates to a semiconductor device formed by using a semiconductor film having a crystalline structure, and to a method of manufacturing the semiconductor device. In particular, the present invention relates to a semiconductor device containing a field effect transistor in which a channel forming region is formed by a crystalline semiconductor film formed on an insulating surface, and to a method of manufacturing the semiconductor device.
2. Description of the Related Art
Techniques of forming an amorphous silicon film on an insulating substrate such as glass, crystallizing the amorphous silicon film, and then forming semiconductor elements such as transistors have been developed. In particular, techniques of crystallizing amorphous silicon films by irradiating laser light have been applied to techniques of manufacturing thin film transistors (TFTs). Transistors manufactured by using a semiconductor film having a crystalline structure (crystalline semiconductor film) are applied to liquid crystal display devices, typically flat surface type display devices (flat panel displays).
The application of laser light in semiconductor manufacturing processes has developed in techniques of recrystallizing damaged layers and amorphous layers formed in a semiconductor substrate or a semiconductor film, and techniques of crystallizing an amorphous semiconductor film formed on an insulating surface. A suitable laser oscillator apparatuses normally use a gas laser, typically an excimer laser, or a solid state laser, typically a YAG laser.
An example of crystallizing an amorphous semiconductor film by laser light irradiation is polycrystallization as disclosed in JP 62-104117 A, in which the laser light scanning speed is at high speed, equal to or greater than the beam spot size×5000/sec, and the amorphous semiconductor film thus does not reach a completely melted state. A technique of effectively forming a single crystal region by irradiating elongated laser light to a semiconductor film formed into an island shape is disclosed in U.S. Pat. No. 4,330,363. Alternatively, a method is known for processing laser light into a linear shape beam by using an optical system and then irradiating the beam, as in a laser processing apparatus disclosed in JP 8-195357 A.
In addition, a technique for manufacturing a transistor by irradiating the second harmonic of laser light, emitted using a solid state laser apparatus such as an Nd:YBO4 laser, to an amorphous semiconductor film, thus forming a crystalline semiconductor film having a large grain size compared to conventional crystalline semiconductor films, is disclosed in JP 2001-144027 A.
However, polycrystals result if crystallization is performed by irradiating laser light to an amorphous semiconductor film formed on a level surface, defects such as crystal grain boundaries are formed arbitrarily, and crystals with aligned orientation cannot be obtained.
Grain boundaries are included as crystal defects, and the crystal grain boundaries become carrier traps, and causes for lowering the mobility of electrons or holes. Furthermore, semiconductor films in which distortions and crystal defects do not exist cannot be formed because of volumetric contraction of the semiconductor film, thermal stress with a base, lattice mismatching, and the like that accompany upon crystallization. Unless otherwise using a particular method in which a laminated SOI (silicon on insulator) is used, it has not been possible to obtain a quality equivalent to that of a MOS transistor, which is formed on a single crystal substrate, in a crystalline semiconductor film that is formed on an insulating surface and then crystallized or recrystallized.
The aforementioned flat panel display devices and the like have built-in transistors in which a semiconductor film is formed on a glass substrate, but it is nearly impossible to dispose the transistors so as to avoid arbitrarily formed grain boundaries. That is, unintentionally included crystal grain boundaries and crystal defects have not been able to be excluded by strictly controlling the crystallinity of transistor channel forming regions. In short, not only do the electrical characteristics of the transistor degrade, but also this becomes a cause of dispersion in the characteristics of individual elements.

Semiconductor device having insulating stripe patterns

Semiconductor Energy Laboratory Co., Ltd.


A memory cell includes a selection transistor and a trench capacitor. The trench capacitor is filled with a conductive trench filling on which an insulating covering layer is arranged. The insulating covering layer is laterally overgrown, proceeding from the substrate with a selectively grown epitaxial layer. The selection transistor is formed in the selectively grown epitaxial layer, comprises a source region connected to the trench capacitor and a drain region connected to a bit line. The junction depth of the source region is chosen so that the source region reaches as far as the insulating covering layer. Optionally, the thickness of the epitaxial layer can be reduced to a thickness by oxidation and a subsequent etching. Afterwards, a contact trench is etched through the source region down to the conductive trench filling, which trench is filled with a conductive contact and electrically connects the conductive trench filling to the source region.

Integrated circuits (ICs) or chips contain capacitors for the purpose of storing charge, such as, for example, a dynamic random access memory (DRAM). In this case, the charge state in the capacitor represents a data bit.
A DRAM chip contains a matrix of memory cells, which are arranged in the form of rows and columns, and are addressed by word lines and bit lines. The reading of data from the memory cells or the writing of data to the memory cells is realized by activating suitable word lines and bit lines.
A DRAM memory cell usually contains a transistor connected to a capacitor. The transistor is referred to as a selection transistor and comprises, inter alia, two doping regions isolated from one another by a channel which is controlled by a gate. Depending on the direction of current flow, one doping region is referred to as the drain region and the other as the source region. The source region is connected for example to the trench capacitor, the drain region is connected to a bit line and the gate is connected to a word line. By the application of suitable voltages to the gate, the transistor is controlled in such a way that a current flow between the source region and the drain region through the channel is switched on and off.
The charge stored in the capacitor decreases over time on account of leakage currents. Before the charge has decreased to a level below a threshold value, the storage capacitor must be refreshed. For this reason, these memories are referred to as dynamic RAM (DRAM).
The central problem in known DRAM variants based on a trench capacitor is the production of a sufficiently large capacitance for the trench capacitor. This problem will be aggravated in future by the advancing miniaturization of semiconductor components. The increase in the integration density means that the area available per memory cell and thus the capacitance of the trench capacitor decrease ever further.
Sense amplifiers require a sufficient signal level for reliably reading out the information situated in the memory cell. The ratio of the storage capacitance to the bit line capacitance is crucial in determining the signal level. If the storage capacitance is too low, the ratio may be too small for generating an adequate signal.
A lower storage capacitance likewise requires a higher refresh frequency, because the quantity of charge stored in the trench capacitor is limited by its capacitance and additionally decreases due to leakage currents. If the quantity of charge falls below a minimum quantity of charge in the storage capacitor, then it is no longer possible for the information stored therein to be read out by a connected sense amplifier, the information is lost and read errors arise.
One way of avoiding read errors is to reduce the leakage currents. Leakage currents can be reduced on the one hand by transistors and on the other hand by dielectrics, such as the capacitor dielectric, for example. An undesirably reduced retention time can be lengthened by these measures.
Stacked capacitors or trench capacitors are usually used in DRAMs. In this case, a trench capacitor has a three-dimensional structure which is formed in a silicon substrate, for example. An increase in the capacitor electrode area, and thus, in the capacitance of the trench capacitor, can be achieved, for example, by etching more deeply into the substrate, and, thus by deeper trenches. In this case, the increase in the capacitance of the trench capacitor does not cause the substrate surface occupied by the memory cell to be enlarged. However, this method is also limited, since the attainable etching depth of the trench capacitor depends on the trench diameter, and, during fabrication, it is only possible to attain specific, finite aspect ratios between the trench depth and trench diameter.
As the increase in the integration density advances, the substrate surface available per memory cell decreases ever further. The associated reduction in the trench diameter leads to a reduction in the capacitance of the trench capacitor. If the capacitance of the trench capacitor is dimensioned to be so low that the charge which can be stored is insufficient for entirely satisfactory read out by the sense amplifiers connected downstream, then this results in read errors.
This problem is explained, for example, in the document DE 199 41 148, the selection transistor, which is usually arranged next to the trench capacitor, being arranged above the trench capacitor. As a result, the trench of the trench capacitor can take up a part of the substrate surface which was conventionally reserved for the transistor. Through this arrangement, the trench capacitor and the transistor share part of the substrate surface. This arrangement is made possible by an epitaxial layer grown above the trench capacitor.
What is problematic, however, is the electrical connection of the trench capacitor to the transistor. Purely lithographic methods for fabricating the electrical connection require a minimum distance between the trench capacitor and the transistor for the lithographic alignment of the individual lithographic planes with respect to one another. Through purely lithographic methods, the memory cells in the memory cell array require a relatively large area and are unsuitable for integration in a large-scale integrated cell array.
What is disadvantageous about the memory cells known from the prior art is that the resistance of the electrical connection between the trench capacitor and the source region of the transistor has a relatively large value, which slows down the access to the memory cell.
A further disadvantage of the prior art is that a sufficient retention time is only achieved by complex insulation measures which require a large number of processing steps. In this case, the electrical contact is insulated from the substrate in a complex manner.

Dram memory cell with a trench capacitor and method for production thereof


We have fabricated miniature planar IR waveguides of thickness 30-50 .mu.m, consisting of 12-mm long, 2-mm wide strips of Ge supported on ZnS substrates. Evidence for efficient propagation of broadband IR light through these waveguides is provided by the presence of characteristic high and low frequency optical cut-offs of Ge; by the observation of an oscillatory interference pattern in the transmittance spectrum, which exhibits a dependence on waveguide thickness and propagation angle closely matching waveguide theory; and by the detection of strong evanescent-wave absorption from small (2 mm.sup.2) droplets of liquid, e.g. water, on the waveguide surface. As also predicted by theory, the surface sensitivity (detected light absorbance per unit area of sample-waveguide contact) was shown to increase as a function of incidence or bevel angle.

The development of mid-infrared (IR) waveguides has been driven by their use as remote or small-sample-size chemical sensors for surface sensitive spectroscopy. Such waveguides can be thought of as miniaturized multiple reflection elements (MREs) wherein the incident light undergoes total internal reflection at the interface between media of different refractive indices. At each internal reflection within the waveguide, a portion of the optical field, the evanescent wave, extends beyond the high-index waveguide into the adjacent low-index medium, to a depth (d.sub.p) dependent on the angle of incidence and the ratio of the two refractive indices..sup.1 The ability of molecules outside the high-index waveguide, but near its surface, to absorb energy travelling through the waveguide via this evanescent wave makes possible the phenomenon known as attenuated total reflection (ATR) or evanescent-wave spectroscopy (EWS).
In the IR region, high-refractive-index materials as Ge, Si, and KRS-5 (Tl.sub.2 BrI), cut and polished as prisms having trapezoidal or parallelogram cross-sections and dimensions on the order of 50.times.10.times.2 mm, are in common use for EWS measurements. These macroscopic waveguides typically have throughputs matched to commercial FTIR spectrometers, i.e. in the vicinity of 1-10 mm.sup.2 -stearadian. Commercially available IR fiber optics (multimode cylindrical waveguides made of, e.g., chalcogenide glass),.sup.2,3 have more recently been used as EWS sensors..sup.4,5 These optical fibers typically have much lower throughputs than the prism MREs, complicating somewhat their use with commercial IR spectrometers. Nevertheless, when properly coupled to a small-area (low-noise) IR detector, fiber optics display the advantage that miniaturization allows smaller amounts (.mu.L) of sample to be detected..sup.6-9 This advantage arises from the fact that, while the surface sensing area is smaller, the light experiences a larger number of reflection per unit length of waveguide, yielding a concomitant increase in evanescent path length. It would be desirable to see how far this advantage could be extended, i.e. how thin an EWS waveguide or fiber could be made. However, it becomes impractical to make a free-standing IR fiber less than .about.50 .mu.m in diameter. Thus, we are interested in investigating the possibility of using supported thin planar waveguides for EWS applications.
Most thin planar waveguide development has been in the visible region, where low-loss transparent materials (polymers and glasses) are commercially available and easy to manipulate. Such waveguides have generally been used in conjunction with single-frequency lasers, which provide high luminosity, monochromaticity, and fine control over the launch angle, and have been used for absorption, Raman, and fluorescence analytical methods..sup.10-17 In contrast, IR-transmissive materials with the requisite high refractive indices and low attenuation values are either very brittle, or have not had techniques developed to allow them to be deposited (e.g. by evaporation or sputtering techniques) as uniform and well-adhered films of the desired thicknesses of 1-100 .mu.m..sup.18 To our knowledge, there have been only two reports in the literature of mid-infrared transmitting planar waveguides, both utilizing monochromatic (laser) light to demonstrate coupling and guiding, rather than broadband light which is likely to be more suitable for general chemical sensing..sup.19,20
Nevertheless, the same theory should describe both visible and infrared waveguides, and this theory indicates that with appropriate coupling methods it should be possible to use IR supported planar waveguides to perform broadband IR chemical sensing..sup.21 We have now proven this by fabricating supported planar waveguides as thin as 30 .mu.m with good broadband transmission, which demonstrate many of the characteristics predicted by planar waveguide theory..sup.22 In particular, they show a great increase in the sampling sensitivity as compared to previous evanescent-wave absorption measurements.

Support planar germanium waveguides for infrared evanescent-wave sensing


A grill with a removable smoker unit comprises a pan, a body, a pan cover, a smoker unit and a socket unit, wherein the smoker unit comprises a smoker box and a heating tube member with two plug terminals. The smoker unit is removably mounted on one side of the body, wherein there is a hole in the pan where the smoker unit inserts into the body, and a removable insulation lid mounted on the hole. The socket unit is mounted in the body, and provides electrical connection. The socket unit has holes for receiving the plug terminals. The grill with these structures not only has the conventional functions, but also provides an optional smoking function.

Various means in cooking food are known, for example, frying, boiling, grilling, baking, smoking, steaming, etc., and different cooking means bring different food taste. House-hold appliances with various functions such as grills had been used in the kitchen. Conventional grills cook food by electric heating, and are advantageous as they are clean, safe, convenient and fast speed, and as a consequence are favored by consumers. The conventional grill has only the grilling function, and usually comprises a pan, a body, a grill lid and electric heating members, the pan mounted on the body, the electric heating members mounted on the bottom of the pan and embedded in the body, the cover used for covering the pan and forming a closed cooking space with the pan.
Therefore, it is readily apparent that there is a need for a multi-functional grill.

Tsann Kuen (China) Enterprises Co., Ltd.


To determine the total organic carbon content of a flowing liquid in a continuous process, water and oxidizing agents enter lower ports in a continuous column and flow upwardly along a helical path with air gaps as they are mixed. The helical reaction path is formed by a helical glass cylinder between an ultraviolet lamp and outer wall of a continuous glass tube to cause rapid motion of the liquid. An ultraviolet lamp extends downwardly through the center of the column so that the outer confining surface of the helical path is the outer surface of the ultraviolet lamp, causing the liquid to move rapidly in intimate contact with the ultraviolet lamp to receive intense radiation. An air gap permits escape of air and reduces bubble size to reduce plug flow.

This invention relates to apparatuses and methods for sensing impurities in water.
It is known to determine the amount of organic carbon in water being tested by oxidizing the organic carbon in a sample of water and measuring the amount of carbon dioxide obtained by such oxidation. One class of techniques and apparatus for measuring organic carbon are continuous in operation. In a continuous process, the organic carbon in water is oxidized as the water flows through an ultraviolet reactor and the amount of water flowing through the reactor is measured. The carbon dioxide formed by oxidizing the organic carbon in the measured water is also measured to provide an indication of the amount of organic carbon in a unit of water.
In a prior art continuous process for measuring the total organic content of water, each of the stages for oxidation of carbon has its own ultraviolet source and may have its own source of oxidizing agent and/or oxygen or there is a single ultraviolet source in a single stage.
The prior art apparatuses and techniques for measuring the total organic carbon content of water has several disadvantages, such as for example: (1) there is a tendency for some of the carbon dioxide to escape before it is collected and measured; (2) in those embodiments in which several ultraviolet light sources are used, the cost is high; and (3) it is difficult to obtain complete oxidation of the organic carbon.
Certain prior art patents disclose the flow of water in a helical path adjacent to an ultraviolet lamp for the purpose of sterilization or purification of water. However, these patents do not need residence chambers that interrupt the helical flow or bubble-size reduction provisions nor are they carbon measuring apparatus. They are not analytical instruments at all and are not concerned with the completeness of oxidation of carbon as an approach to measuring carbon content.
Some such patents and patent applications are U.S. Pat. Nos. 4,008,045; 5,675,153; 5,069,885; 2,501,290; Canadian Patent 674,555; European patent application 0202891; German Offenlegungsschrift 2,327,084; and French Patent 1,278,161.


Flexible graphite sheet having embedded ceramic fibers extending from its surfaces into the sheet to increase the permeability of the sheet to resin. The resin impregnated sheet is formed into a sealing gasket.

The term "flexible graphite" as used herein represents the exfoliated reaction product of rapidly heated natural graphite particles which have been treated with an agent that intercalates into the crystal-structure of the graphite to expand the intercalated particles at least 80 or more times in the direction perpendicular to the carbon layers in the crystal structure. Flexible graphite and the making thereof is described in U.S. Pat. No. 3,404,061 Shane et al. Expanded, i.e. exfoliated graphite may be compressed into thin sheets (hereinafter referred as flexible graphite "foil") with a density approaching theoretical density, although a density of about 50 to 85 lbs./ft..sup.3 is suitable for most applications, including compression into shapes suitable as seal rings in engine exhaust and other applications.
A common method for making expandable graphite particles, described by Shane et al in U.S. Pat. No. 3,404,061 the disclosure of which is incorporated herein by reference. In the typical practice of this method, natural graphite flakes are intercalated by dispersing the flakes in a solution containing an oxidizing agent e.g., a mixture of nitric and sulfuric acid. The intercalation solution contains oxidizing and other intercalating agents known in the art. Examples include those containing oxidizing agents and oxidizing mixtures, such as solutions containing nitric acid, potassium chlorate, chromic acid, potassium permanganate, potassium chromate, potassium dichromate, perchloric acid, and the like, or mixtures, such as for example, concentrated nitric acid and chlorate, chromic acid and phosphoric acid, sulfuric acid and nitric acid, or mixtures of a strong organic acid, e.g. trifluoroacetic acid, and a strong oxidizing agent soluble in the organic acid. A preferred intercalating agent is a solution of a mixture of sulfuric acid, or sulfuric acid and phosphoric acid, and an oxidizing agent, i.e. nitric acid, perchloric acid, chromic acid, potassium permanganate, hydrogen peroxide, iodic or periodic acids, or the like. Although less preferred, the intercalation solutions may contain metal halides such as ferric chloride, and ferric chloride mixed with sulfuric acid, or a halide, such as bromine as a solution of bromine and sulfuric acid or bromine in an organic solvent. After the flakes are intercalated excess solution is drained from the flakes and after washing with water, the intercalated graphite flakes are dried and are expandable upon exposure to a flame for only a few seconds. The thus treated particles of graphite are hereafter referred to as "particles of intercalated graphite". Upon exposure to high temperature, the particles of intercalated graphite expand in dimension as much as 80 to 1000 or more times its original volume in an accordion-like fashion in the c-direction, i.e. in the direction perpendicular to the crystalline planes of the constituent graphite particles. The exfoliated graphite particles are vermiform in appearance, and are therefore commonly referred to as worms. The worms may be compressed together into flexible sheets which, unlike the original graphite flakes, can be formed and cut into various shapes.
Flexible graphite foil is coherent, with good handling strength, and flexible graphite foil can be wound into rolls and can also be wrapped around metal fixtures such as mandrels, possesses desirable heat transfer properties and is, accordingly, particularly useful for high temperature applications such as engine exhaust seal ring applications. It has been proposed to increase the sealability of flexible graphite sheet or foil by impregnating the same with resin. However, the surface layers of flexible graphite sheet or foil, due to the alignment of exfoliated graphite particles and the constituent layers of atoms parallel to the surface of the flexible sheet or foil, resist resin impregnation when the sheet or foil is immersed in liquid resin. However, due to the well known anisotropy of flexible graphite, resin will flow readily within the flexible graphite sheet in directions parallel to the opposed parallel planar surfaces of the sheet or foil and the planes of the constituent graphite particles of the sheet, i.e. transverse to the "c axis" direction of the graphite particles if penetration into the flexible graphite sheet can first be achieved.
Accordingly, it is an object of the present invention to provide a flexible graphite sheet, or foil, of increased permeability to enable increased resin impregnation.


A construction for sunglasses adapted to be fitted over prescription eyewear having conventional nose pads and eyeglass temples comprises a lens frame having lens rims with corresponding lenses supported therein, a bridge between the lens rims and right and left temples extending rearwardly from corresponding pivots with the lens frame. The lens frame is free of any rearwardly-extending panels along the lower portion of the lens rims in order to avoid interference with the prescription eyewear, the bridge is designed with a nose-encircling edge permitting the sunglasses-prescription eyewear combination to be supported by the nose-pads of the eyewear, and the temples of the sunglasses include concavities adapted to receive the temples of the prescription eyewear, all to insure a more comfortable fit of the sunglasses over the prescription eyewear.

1. Field of the Invention
The present invention is directed to designs and constructions for sunglasses, and specifically to such designs and constructions which permit the sunglasses to be fitted over prescription eyewear when in use.
2. Description of the Prior Art
There are a number of designs and constructions for eyewear which are intended to protect the user from light glare and ultraviolet radiation caused by the sun. It is of course well known to tint the lens of prescription eyewear for use as sunglasses; it is also well known to adapt the construction of the sunglasses so as to fit over a pair of untinted prescription eyeglasses.

Sunglasses for fitting over prescription eyewear