The present invention relates to the production of oil and fat containing acylglycerol esters including diacylglycerols, medium-chain and long-chain fatty acid triacyglycerols comprising esterification reaction between an acyl group donor and an acyl group acceptor in the presence of a heterogeneous chemical catalyst consisting of an ion-exchange resin preparation to obtain a reaction fluid that is further subjected to dehydration and at least one separation method, thus producing diacylglycerols and/or medium-chain and long-chain fatty acid triacyglycerols at a high yield in a short period of time.

Glycerol molecule provides three sites for combining with fatty acids to make ester products. Common oils and fats are triesters of glycerol called triacylglycerols, mono- and diacylglycerols are partial glycerol esters that are being increasingly used as emulsifiers in both foods and pharmaceuticals. Currently there is a growing need to make tri- and diacylglycerols that contain specific nutritionally important fatty acids at specified positions on the three-pronged glycerol backbone.
Diacylglycerols are widely used in a variety of applications such as additives for improving plasticity of oils and fats, as well as edible oils in the food industry, and as a base material for the production of cosmetics, drugs, etc. Generally, the preparation of such diacylglycerols involves an esterification reaction of glycerol with its corresponding fatty acid, an alcohol interchange reaction of glycerol with oil or fat, or the like, with the use of an alkali catalyst, or an enzyme such as a lipase, or the like. The use of an enzyme catalyst has been claimed to be the preferable choice, as compared to the chemical reaction process, from the viewpoints of the yield and purity of the diacylglycerols synthesized and energy savings. However, this is only true if the chemical reaction processes make use of conventional alkali catalyst, high reaction temperature and pressure.
Japanese Patent Application No. 71495/1989 discloses lipase-catalysed reaction processes in which a fatty acid or the like is reacted with glycerol in the presence of a 1,3-position selective lipase while removing water formed by the reaction outside the system, to obtain a diacylglycerol at high yield and purity. PCT Patent Application No. WO 99/09119 by Kao Corporation discloses a process for producing high-purity diacylglycerols at a low cost and more efficiently than conventional esterification and glycerolysis processes, which comprises partially hydrolyzing an oil or fat, followed by esterifying the resultant product with glycerol. Japanese Patent Application No. 234391/1998 discloses processes in which a mixture of a fatty acid or the like and glycerol or the like is reacted in a flow tube type reactor filled with a lipase while controlling the superficial velocity of the mixture in the reactor to at least 0.05 cm/s. Japanese Patent Application No. 330289/1992 discloses processes in which glycerol is added in an equimolar amount or more to a fatty acid to react, the reaction is stopped when the concentration of a diacylglycerol has been enhanced, insoluble glycerol is separated, and the reaction is further conducted while dehydrating, thereby synthesizing diacylglycerol at a high esterification reaction rate by improving dehydration efficiency. U.S. Pat. No. 6,361,980 discloses a process for preparing a diacylglycerol, comprising: an enzyme-packed tower comprising an immobilized lipase preparation, carrying out an esterification reaction between: (1) an acyl group donor selected from the group consisting of a fatty acid, a lower alcohol ester thereof, and a mixture thereof; and (2) an acyl group acceptor selected from the group consisting of glycerol, a monoacylglycerol, and a mixture thereof; to obtain a reaction fluid from said enzyme-packed tower; reducing a water content or a lower alcohol content in said reaction fluid; and subsequent to said reducing, re-circulating the reaction fluid to said enzyme-packed tower, wherein a residence time of said reaction fluid in said enzyme-packed tower is 120 seconds or less; to obtain a diacylglycerol, wherein said reducing comprises dehydrating or de-alcoholising said reaction fluid is by feeding said reaction fluid though a spray nozzle, in a dehydration process. United States Patent Application No. 2003/0104109 discloses a method for producing 1,3-diacylglycerol oil from triacylglycerol, comprising mixing the triacylglycerol containing oil with glycerol and a homogenous chemical catalyst comprising an alkali metal salt or alkali earth metal salt of a monocarboxylic acid or a dicarboxylic acid, or a mixture thereof, to achieve glycerolysis, wherein the 1,3-diacylglycerol oil is produced.
Among the above-described processes, however, the technique disclosed in Japanese Patent Application No. 71495/1989, PCT Patent Application No. WO 99/09119, Japanese Patent Application No. 234391/1998, Japanese Patent Application No. 330289/1992 and U.S. Pat. No. 6,361,980, make use of expensive lipases as catalyst for the reaction, and therefore, are difficult to produce diacylglycerol at a low cost; the technique disclosed in Japanese Patent Application No. 330289/1992 involves technical difficulties such as the necessity of stopping the reaction at a specific time when the concentration of diacylglycerol reaches a peak; the technique disclosed in Japanese Patent Application No. 234391/1998 could not obtain sufficient purity of diacylglycerol; the technique disclosed in United States Patent Application No. 2003/0104109 requires an immediate removal of the homogenous chemical catalyst after the reaction by means of neutralization, which is not easy to operate at an industrial level and may lead to diacylglycerol oil loss.
Obesity is a well-known lifestyle disease that is widespread in affluent nations and rapidly on the rise in developing countries. It is often related to many diseases such as diabetes, hyperlipemia, hypertension and ischemic heart diseases. One of the reasons of the onset of obesity lies in the excessive intake of fat in our daily diet, which results in the increased accumulation of body fat.
In view of this situation, numerous fat substitutes or low-calorie fats have been developed to replace or reduce the use of conventional fats. Examples of such fats include sucrose fatty acid esters, alkyl glycoside fatty acid polyesters, dialkyl dihexadecylmolonate, esterified propoxylated glycerol and long-chain and short-chain fatty acids of triacylglycerols. However, such fats do not satisfy important characteristics such as nutritional safety, desirable physical property, heat stability, and flavour; all of which are critical for the fat to be acceptable by consumers. Medium-chain and long-chain fatty acid triacylglycerols have been shown to satisfy all of the above criteria and to lower body fat accumulation, and the production is therefore desirable.
United States Patent Application No. US2004/0191391 discloses a lipase-catalysed reaction process in which an edible oil or fat is transesterified or acidolysed with medium-chain fatty acids or medium-chain fatty acids triacylglycerol. This process makes use of expensive lipases as catalyst for the reaction, and therefore, is difficult to produce medium-chain and long-chain fatty acids triacylglycerol at a low cost.
European Patent Application No. EP1642959 discloses a 3-stage process for preparing high purity symmetrical triacylglycerols comprising of medium-chain fatty acids at sn-1 and sn-3 positions and a long-chain fatty acid at sn-2 position in which, (1) a medium-chain fatty acid triacylglycerol is randomly transesterified with a long-chain fatty acid triacylglycerol in the presence of an enzyme or a chemical catalyst to obtain a reaction product containing a triacylglycerol comprising a medium-chain fatty acid and a long-chain fatty acid, (2) reaction product from (1) is transesterified with an alcohol monoester of a medium-chain fatty acid in the presence of a 1,3-position specific enzyme, and (3) separating the alcohol monoester of the medium-chain fatty acid and the alcohol monoester of the long-chain fatty acid monoester to obtain the symmetrical triacylglycerol composing of medium-chain fatty acids at the sn-1 and sn-3 positions and a long-chain fatty acid at the sn-2 position. This process also makes use of expensive lipases as catalyst and alcohol monoesters of medium-chain fatty acids as raw materials for the transesterification reaction, and therefore, makes the process difficult to produce medium-chain and long-chain fatty acid triacylglycerols at a low cost.
United States Patent Application No. US2004/0171127 discloses a process for producing medium-chain and long-chain fatty acid triacylglycerol comprising of medium-chain fatty acids esterified to the sn-1 and sn-3 positions and a ω-6 series polyunsaturated long-chain fatty acid having 18 or more carbon atoms and 2 or more double bonds, but not containing ω-3 series polyunsaturated fatty acid, esterified to the sn-2 position of the triacylglycerol molecule, by means of enzymatic transesterification of medium-chain fatty acids and an oil or fat containing at least one polyunsaturated fatty acid of the abovementioned type, using an immobilized lipase. Similarly, this process also involves the use of expensive lipases as catalyst, and therefore, increases the overall production cost of medium-chain and long-chain fatty acid triacylglycerols.
In view of the above, it is advantageous to provide a method of producing fats and oil containing acylglycerol esters. This method would be desirable to produce diacylglycerols and/or medium-chain and long-chain fatty acid triacyglycerols at a high yield and low cost in a short period of time, which has potential applications in the continuous commercial production of diacylglycerols and/or triacylglycerols having medium-chain and long-chain fatty acids at industrial level.


The present invention discloses a system and method for simultaneously installing a pipe loop and a grout pipe in a wellbore. In another aspect such a system is then used to grout the wellbore by releasing the grout pipe from the pipe loop or from a bottom member connected with the pipe loop and then introducing grout through the pipe into the wellbore as the grout pipe is removed upwardly from the wellbore. In another aspect a drilling-grouting system is provided with which while one hole is being drilled a previously-drilled hole is being grouted.

1. Field of the Invention
The present invention is directed to underground heat exchange systems and to apparatus and methods for installing a loop of pipe in a hole in the earth.
2. Description of Related Art
The prior art discloses a variety of systems and apparatuses for installing ground heat exchange pipe loops in a wellbore. In certain prior art systems a wellbore is drilled, e.g. a drill rig drills a vertical four to four-and-a half inches in diameter hole, e.g. to a depth of about 250 feet. In one aspect a single piece of polyethylene pipe attached to a sinker bar is introduced into the hole and then pulled out of the hole manually while grout is introduced into the hole. In another aspect a polyethylene pipe loop is pushed to the bottom of the hole by a wire-line retrievable sinker bar. When the sinker bar is removed, a series of 2 inch PVC tremmie pipes are screwed together and lowered to the bottom of the hole. A bentonite clay mixture called grout is then batch mixed at the surface and pumped into the tremmie pipe. As each batch is pumped into the hole the tremmie pipe string is raised and one 20 foot section of pipe is removed from the hole and laid on the ground. When the hole is filled to the surface and all of the tremmie pipe has been removed the drill rig is moved to another drilling position, usually at least 15 feet away. When all of the pipe loops have been installed (e.g. one loop for each ton of heating and cooling equipment), the drill rig is removed from the site. A trench (e.g. about four feet deep) is then dug to contain pipes that interconnect all of the pipe loops. Once the trenching is completed the connecting pipe is laid into the trench and heat fused to each of the vertical pipe loops. The connection pipe is then pressure tested and buried and becomes a circulating manifold which carries water between the earth and a heat pump located within an adjacent building. The trenching and manifolding of the surface pipe typically takes as much time as the wellbore drilling and pipe installation.
The prior art discloses numerous in-ground heat exchanger systems (e.g. see U.S. Pat. Nos. 5,244,037; 5,261,251); and grouting systems (see, e.g. U.S. Pat. No. 5,435,387).


A circuit for clamping a TV signal includes an input capacitor coupled to the TV signal, an analog-to-digital converter that outputs a digital signal corresponding to TV signal, a comparator that compares the digital signal to a black level signal, and a high impedance driver that charges the input capacitor in response to an output of the comparator.

1. Field of the Invention
The present invention relates to a clamping circuit for our use in a color television circuit, and more particularly, to a high impedance clamping circuit for use in digital television circuit.
2. Related Art
FIG. 1 shows a standard NTSC composite video signal. According to IRE (Institute of Radio Engineers) standard, 1 Volt Peak to Peak Video is divided up into 140 IRE units. This is done to make numbers for luminance levels easier to communicate. The amplitude of the video signal from blanking (zero volts) to peak white is 0.714286 volts or 100 IRE units. Synchronization signals extend from blanking to −1.285714 volts/−40 IRE units.
A horizontal sync is the −40 IRE pulse occurring at the beginning of each line. This pulse signals the electronic beam of the picture monitor to go back to the left side of the screen and trace another horizontal line picture information. The horizontal sync (HSYNC) signals the beginning of each new video line.
Luminance is a signal which represents brightness, or the amount of light in the picture. This is the only signal required for black and white pictures, and for color systems it is obtained as a weighted sum (Y=0.3R+0.59G+0.11B) of the R, G and B signals.
Chroma is the characteristics of color information, independent of luminance intensity. Hue and saturation are qualities of chroma. The chroma signal consists of two quadrature components modulated on to a carrier at the color burst frequency. The phase and amplitude of these components determine the color content at each pixel.
The horizontal sync is followed by a back porch, which is used as a reference level to restore the DC component (i.e., brightness) of an otherwise floating AC-coupled video signal. This process of DC level restoration is named "clamping", and takes place during the back porch. In color systems, a burst (called "color burst") of sub-carrier frequency is located on a back porch of the composite video signal, as shown in FIG. 1. The back porch represents a black level of the video signal, while the color burst serves as a color synchronizing signal to establish a frequency and phase reference for the chrominance signal. Thus, the color burst is a high-frequency region that provides a phase and amplitude reference for the subsequent color information.
A clamp is a circuit that restores the DC component of a signal. A video clamp circuit, usually triggered by the horizontal synchronizing pulses, re-establishes a fixed DC reference level for the video signal. A major benefit of clamping is the removal of low-frequency interference, especially power line hum.
In a digital system, an A/D converter must sample the analog composite signal before the luma and chroma are separated into their respective channels. The clamp, or a DC restore circuit, is needed to keep the analog signal within the dynamic range of the A/D converter. The blank level is measured during the color burst area (after a digital low pass filter), but the clamp pulse cannot be applied to the incoming analog signal during this same time. The analog burst must be maintained because it is used to demodulate the chroma into its baseband signal. Adding a pulse during the back porch is difficult due to tolerance on the 10.8 μs from sync to active video and extra long bursts for copy protection (Macrovision).

High impedance digital full line video clamp


A versatile and highly effective massage device has an active surface for bringing into contact with tissue to be treated, and means for driving the active surface in an oscillating pivoting movement about an axis. The active surface has, in cross section, different radii perpendicular to the axis in different directions and can be rotated parallel to the axis in order to bring in each case different zones of the active surface into contact with the tissue.

The present invention relates to a massage device for treating acute and chronic microcirculation disorders in warm-blooded beings.
DE-A 4 408 867 discloses a massage device which, on a housing that can be held and guided in the hand, has an active surface which is connected to the housing so as to pivot about an axis. This active surface is cylindrical, the axis of rotation of the cylinder coinciding with the pivot axis. When the active surface is pressed against a body area that is to be treated, the skin touched by the active surface, and the underlying tissue, are set in oscillation by friction parallel to the body surface. The amplitude of the oscillation is predetermined here by the structure of the massage device.
DE 4 443 756 D1 describes a massage device with an active surface whose radius, measured from a pivot axis of the device, differs in different directions. This device is a large-format fixed device in which the patient places an entire body part such as the lower leg on the active surface, so that the body part to be treated essentially as a whole follows the movement of the active surface. Since the position of the patient relative to the device cannot be readily changed during treatment, the movement transmitted from the device to the body part to be treated is always the same during a treatment session.
The object of the present invention is to create a versatile and therapeutically highly effective massage device. According to the invention, this object is achieved with the features of claim 1. Advantageous embodiments are defined in the dependent claims.
The present invention makes it possible, by means of simply changing the orientation of the active surface of the massage device with respect to the tissue to be treated, to modify the amplitude of the pivoting movement. Surprisingly, this modulation of the amplitude permits a considerably longer-lasting and deeper therapeutic action, in the treatment of disorders associated with impaired microcirculation, than is possible with the conventional techniques. Tests revealed significant relief or even total disappearance of the symptoms, even in patients who did not respond to the conventional methods.
Indicated uses for the device according to the invention are therefore cases of painful or tensed musculature, musculoskeletal disorders of the nervous system, support and movement apparatus, chronic abuse of alcohol, medication and drugs, acute traumas, following surgical interventions, but also in cases of chronic diseases of the rheumatic type, psychiatric disorders, chronic fatigue syndrome, osteoporosis, multiple sclerosis, gout, diabetes, cellulite, Sudeck""s syndrome, brain pressure, vertigo, Mxc3xa9nixc3xa8re""s disease, circulation problems, pain, tumors, apoplexy, tactile and sensory hypesthesias and paresthesias, sensory stimulation, environmentally induced diseases and all changes affecting the matrix.
It is preferable that the radius of the active surface changes continuously over at least one area thereof. This makes it possible to exert on the tissue, in addition to the surface-parallel movement, an oscillating pressure of identical frequency. This pressure is not distributed uniformly over the patient""s body surface contacted by the active surface, but instead increases in the direction of greater radii of the active surface. In this way, a pressure gradient is generated rhythmically in the tissue, by means of which tissue fluid is pumped through the tissue parallel to the surface. This pump action makes it possible to increase the throughput of body fluids such as blood or lymph through the treated tissue zones, and thus to significantly improve the supply of nutrients to the tissue and the breakdown of metabolic waste products.
The invention can be designed as a fixed device as well as a hand-guided device. A particular advantage of the hand-guided device is that the user can, with the same hand guiding the device, detect the hardened area of the treated tissue and, by simply turning the massage device about the axis of the active surface, adapt the amplitude of the massage movement to the detected degree of hardening or rhythmically vary the amplitude.

Massage device having an oscillating active contact surface


The present disclosure relates to a lithium-ion battery anode comprising a flexible and free-standing carbon nanotube film, and a plurality of titanium dioxide nanoparticles uniformly adsorbed on a surface of each of the plurality of carbon nanotubes. The flexible and free-standing carbon nanotube film comprises a plurality of carbon nanotubes. A particle size of each of the plurality of titanium dioxide nanoparticles is less than or equal to 30 nanometers. The present disclosure also relates to a lithium-ion battery comprising the lithium-ion battery anode.

Carbon nanotube are a novel carbonous/carbonaceous material formed by one layer or more layers of graphite. A distance between two layers of graphite in the carbon nanotube is about 0.34 nanometers, which is greater than the distance between two layers in natural graphite. Thus, carbon nanotube is a suitable material for using as the anode of the lithium battery.
However, an energy density of conventional carbon nanotube anode is small, and conventional carbon nanotube anodes exhibit a large lattice change and a small operating voltage during a process of lithium insertion/extraction. Therefore, conventional carbon nanotube anodes can not avoid a collapse of electrodes and suppress a formation of solid electrolyte interface (SEI) layers, and lithium dendrites will appear in conventional carbon nanotube anodes.

Lithium-ion battery anodes and lithium-ion batteries using the same


A system and method to measure channel quality in terms of signal to interference plus noise ratio for the transmission of coded signals over fading channels in a communication system. A Viterbi decoder metric for the Maximum Likelihood path is used as a channel quality measure for coherent and non-coherent transmission schemes. This Euclidean distance metric is filtered in order to smooth out short term variations. The filtered or averaged metric is a reliable channel quality measure which remains consistent across different coded modulation schemes speeds. The filtered metric is mapped to the signal to interference plus noise ratio per symbol using a threshold based scheme. Use of this implicit signal to interference plus noise ratio estimate is used for the mobile assisted handoff in a cellular system, power control and data rate adaptation in the transmitter.

The present invention relates generally to digital communication systems and, more particularly, to communications systems which utilize digital transmission schemes.
As communication systems continue to grow worldwide at a rapid pace, the need for frequency spectrum efficient systems that accommodate both the expanding number of individual users and the new digital features and services such as facsimile, data transmission, and various call handling features is evident.
As an example, current wireless data systems such as the cellular digital packet data (CDPD) system and the IS-130 circuit switched time division multiple access data system support only low fixed data rates that are insufficient for several applications. Since cellular systems are engineered to provide coverage at the cell boundary, the signal to interference plus noise ratio (abbreviated as SIR, SNR, or C/(I+N)) over a large portion of a cell is sufficient to support higher data rates. Existing adaptive data rate schemes using bandwidth efficient coded modulation are currently being proposed for increasing throughput over fading channels such as those encountered in mobile radio wireless systems. However, these schemes do not dynamically adjust the coded modulation to adapt to the channel conditions.
Coded modulation schemes with different bandwidth efficiencies have different error rate performances for the same SIR per symbol. As result, at each SIR, the coded modulation scheme that results in the highest throughput with acceptable retransmission delay is desired. Therefore, the detection of channel quality in terms of SIR or achievable frame error rate is very important. As an example, fast and accurate methods to measure either the SIR or to estimate the FER are not available for cellular systems. Thus, there is a need to determine the channel quality based on the measurements, or metrics, of the SIR or the achievable frame error rate (FER) for the time varying channel.
The difficulty in obtaining these metrics in communications systems such as cellular systems is based on the time varying signal strength levels found on the cellular channel. These time varying effects, referred to as fading and distance dependent loss, are the result of the movement of the mobile station (cellular phone) relative to the base station (also known as a cell site). Some recent schemes propose a short-term prediction of the FER, but not the SIR, using the metric for the second best path in a Viterbi decoder. This metric is computationally very intensive and reacts to short term variations in fading conditions. Therefore, there is a need, for an efficient and accurate method for measuring the channel quality in terms of the SIR in a communication system.
Thus, there is a need to determine the channel quality of a communication system based on the measurements (metrics) of the SIR or the achievable frame error rate (FER) for the time varying channel in a digital transmission scheme to obtain a quick and reliable indicator of SIR in noise limited, interference limited and delay spread environments. This need extends for example, to coherent schemes such as M-ary phase shift keying (M-PSK) signaling and non-coherent schemes such as M-DPSK signaling
It is also important to measure channel quality, in terms of SIR or FER, for the purpose of mobile assisted handoff (MAHO) and power control. However, FER measurements are usually very slow for the purpose of rate adaptation, power control and handoff. FER as a channel quality metric is slow because it can take a very long time for the mobile to count a sufficient number of frame errors. Therefore, there is a need for a robust short-term channel quality indicator that can be related to the FER.
As a result, channel quality metrics such as symbol error rate, average bit error rate and received signal strength measurements have been proposed as alternatives. The IS-136 standard already specifies measurement procedures for both bit error rate and received signal strength. However, these measures do not correlate well with the FER, or the SIR, which is widely accepted as the meaningful performance measure in wireless systems. Also, received signal strength measurements are often inaccurate and unreliable. Thus, the SIR is a more appropriate as a handoff metric near the cell boundary where signal quality is rapidly changing.
The present invention is directed to overcoming, or at least reducing the effects of one or more of the problems set forth above.

System and method for measuring channel quality information in a communication system


This invention provides a heating/cooling system including a heating/cooling apparatus, the apparatus comprising a blower unit connected to a heat exchanger unit and both units are enclosed within a duct structure which is continuous from an upstream input end to a downstream output end. The blower unit comprises an electric motor direct-coupled to an impeller and the heat exchanger unit comprises a heat transfer assembly and both blower and heat exchanger units are of a size and configuration as to facilitate their mounting within the space defined by, for example, a pair of building floor joists. The space between the floor joists may be enclosed to function as a return air duct to the apparatus. The heating/cooling apparatus may be adapted for humidifying and dehumidifying air being pumped through the apparatus by the blower unit.

In the art of heating and cooling of building spaces, the units which provide the conditioned air for such spaces are conventionally of a size and capacity as to require that they be installed at locations which are relatively remote from the spaces to be heated and/or cooled. For example, heating and cooling units for single and/or multiple family dwellings are conventionally located in the basement of these type of buildings and they are specified so as to supply conditioned forced air to multiple spaces via ducts which are installed in conjunction with the heating/cooling units. While these units may be of a similar configuration for various type building constructions, the required supply and return ducts are configured according to the architectural design of the particular building. For most heating/cooling installations, the ducts must be customized to a particular building design and this tends to increase the cost of the total heating and cooling system. In many cases the cost of the ducts and their installation may exceed the cost of the heating/cooling unit. This, of course, relates directly to the length and complexity of the duct runs necessary to reach the spaces to be heated and cooled. In this respect also, multi-story commercial buildings are usually designed to have a distance between the floors of about twelve feet allowing for an eight-to-ten foot ceiling height and the remaining two-to-four feet are allocated to the installation requirements of the heating and cooling ducts and other elements of the building construction.
While many advances have been made in the heating and cooling industry as it pertains to heating/cooling unit efficiency and capacity, not much has been accomplished in the elimination of ducts which are necessary to move conditioned air to and from building spaces which are remotely located with respect to a centrally located heating/cooling unit. In this respect also, the specifications made for heating/cooling units which are applied to a particular building construction are usually greater than necessary to heat and/or cool the volume spaces of the building. This is, of course, largely due to the length and complexity of the duct runs. Thus, it is the present practice to use large capacity heating/cooling units to supply conditioned air to multiple building spaces via ducts and this arrangement has not changed irrespective of the other advances in the industry.
It is, therefore, in accordance with one aspect of the present invention an object to provide a heating/cooling system which eliminates much of the ductwork that is required in presently configured heating and cooling systems.
According to another aspect of the invention it is an object to provide a heating/cooling system wherein the unit apparatus may be located in close proximity to the building spaces to be heated and/or cooled.
According to still another aspect of the invention it is an object to provide a heating/cooling apparatus which exhibits an efficiency, capacity, and cost such that multiples of the apparatus may be installed to meet multiple building space requirements, and this, irrespective of the the building design and/or configuration.
In accordance with another aspect of the invention it is an object to provide a heating/cooling apparatus comprised of in-line positioned blower and heat exchanger units which are configured for mounting within the volume space which normally exists between adjacent floor joists of a building structure such that the volume space between adjacent joists may be enclosed to function as the supply and return ducts of the heating/cooling apparatus.
According to still another aspect of the present invention it is an object to provide a heating/cooling apparatus which may be specified to meet varying heating and cooling requirements of various type building spaces.
Finally and in accordance with another aspect of the present invention it is an object to provide a heating and cooling apparatus which facilitates ease of servicing and replacement and the cost of which is dramatically lower than the large sized and high capacity units which are presently being offered by the heating and cooling industry.


In a foreign matter inspection apparatus for a semiconductor wafer, a PMT which detects reflection light, an amplifier which amplifies a signal detected by the PMT and in which response characteristics of amplification are controlled by a control signal, an A/D converter which converts the signal amplified by the amplifier into a predetermined code and outputs the code, a control circuit which generates a control signal based on information of the semiconductor wafer having a correlation with the reflection light, and a data processing circuit which detects a foreign matter on the semiconductor wafer based on the code output from the A/D converter are provided.

A detection circuit of a conventional foreign matter inspection apparatus for a semiconductor wafer examined by the inventors of the present invention as a premise of the present invention will be schematically described with reference to FIG. 5. FIG. 5 is a diagram schematically showing the detection circuit of the conventional foreign matter inspection apparatus for a semiconductor wafer.
More specifically, in the conventional foreign matter inspection apparatus for a semiconductor wafer, laser light 101 is irradiated as irradiation light onto a rotating semiconductor wafer 101, scatter reflection light 102 from a foreign matter or the like present on the semiconductor wafer 104 is detected by a photo multiplier tube (PMT) 103.
The PMT 103 multiplies the incident light by the photo multiplier effect and outputs a current in accordance with the incident light intensity, and it outputs the foreign matter detection signal current based on the scatter reflection light 102 from a foreign matter or the like.
In a detection unit including an I-V conversion circuit 200 and a detection circuit 300, the I-V conversion circuit 200 including a resistor 201 and an operational amplifier 202 performs the conversion to a detection voltage signal based on the foreign matter detection signal current.
Further, in the detection circuit 300, the detection voltage signal is amplified by an amplifier 301 and the voltage is converted into a digital value by use of an A/D converter 302. Thereafter, the digital value is output to a data processing circuit (not shown) as an output code to determine the foreign matter or the like.
It is generally said that the intensity of the scatter reflection light from the foreign matter with a minute diameter is proportional to the sixth power of the diameter of the foreign matter. Therefore, when the foreign matter is to be detected by the light irradiation and the scatter reflection light thereof, the detection signal becomes minute as the size of the foreign matter on the semiconductor wafer to be inspected becomes smaller, and the wide dynamic range is required in accordance with the amplitude range of the detection signal in the detection circuit 300 to detect the detection signal.
Further, when the rotation speed of the semiconductor wafer is increased in order to shorten the inspection time of the semiconductor wafer, the scanning speed on the surface of the semiconductor wafer is also increased, the change ratio of the detection signal per unit time is increased, and the speeding-up is also required in the detection unit.
Incidentally, since the basic trade-off relation exists between the speed and the dynamic range in the A/D converter 302 in general, the dynamic range of the A/D converter 302 is reduced and the minimum resolution is increased as the speed is increased.
Accordingly, as the conventional technology, Japanese Patent Application Laid-Open Publication No. 8-145899 (Patent Document 1) proposes the method in which a plurality of amplifiers that amplify the detection current at different amplification factors are disposed in parallel, and the dynamic range is expanded by the output of the appropriate range of the plurality of amplifier outputs.

Detection circuit and foreign matter inspection apparatus for semiconductor wafer


In a color liquid crystal display apparatus of twisted nematic type, thicknesses of the liquid crystal layer is made different for different color picture elements, thereby optical rotatory dispersion which has been the cause of undesirable light transmittance at 0 voltage input is minimized, so that contrast, range of reproduced color, view angle dependency, etc. are improved, and a color liquid crystal display apparatus capable of displaying splendid picture quality is provided.

1. Field of the Invention
The present invention relates to an improvement in a color liquid crystal display apparatus, and particularly concerns a color liquid crystal display apparatus having twisted nematic liquid crystal combined with a number of color filter elements.
The present invention is usable for color picture display apparatus for a television receiver set, a monitor in a videotape recorder, a view finder of a television camera or a display apparatus of a computer terminal machine.
2. Description of the Prior Art
A color fluid crystal display apparatus has such a characteristics as having small thickness, operable with low voltage power source and consumes very small power, and accordingly its market is large. Furthermore, demand is rapidly growing these years as a flat type display apparatus. Developing from the conventional monocolor type liquid crystal display apparatus, color liquid crystal display apparatuses which uses a number of color filter elements are about to be introduced into actual use.
As operation modes of such color liquid crystal display apparatus for use in color displaying, dynamic scatterinc mode (hereinafter is referred as DSM), twisted nematic mode (hereinafter is referred as TN) and guest-host mode (hereinafter is referred as GH) are considered. Among these modes, TN liquid crystal has a characteristic of small driving power, high contrast and bright display.
Now description is made on the conventional color liquid crystal display apparatus configurated by a TN liquid crystal and color filter elements of red (hereinafter is referred as R), green (hereinafter is referred as G) and blue (hereinafter is referred as B).
Next, let us enter into the configuration of optical characteristic of TN liquid crystal which is an essential matter for the present invention is described.
FIG. 1 shows principle of display by transparent type TN liquid crystal display apparatus. A liquid crystal 1 of nematic type, a pair of paralelly disposed transparent substrates 2a and 2b and a liquid crystal 1 combined therebetween together constitute a liquid crystal cell, and a pair of polarizer 3a and 3b disposed with the polarizing axises in each other vertical relation are provided on the substrates 2a and 2b, respectively. A thick white arrow indicates direction of incident light and its polarization.
In the device of FIG. 1, in a 0 voltage impression state, the liquid crystal stops light as shown in FIG. 1(a). When a voltage above a threshold value (hereinafter is referred as V.sub.th) is applied, the liquid crystal is realigned in the direction of the electric field (provided) that the dielectric constant anisotropy of the liquid crystal is positive), and incident light from the upper substrate passes through the liquid crystal apparatus. Accordingly by application or removal of voltage across the electrodes, contrast of brightness and darkness is obtainable. The above-mentioned type the liquid crystal apparatus wherein a dark state is represented at non-impression of voltage across the electrodes on both substrates is defined as "normally black" type.
In actual apparatus, transmittance T at 0 volt impression is not 0. As a result of the optical rotatory dispersion, a linearly polarized light incident to the cell changes into elliptically polarized wave light and hence passes the cell. Transmittance of parallel light incident normally to the liquid crystal cell at the 0 volt impression state is given by the following equation (C. H. Gooch, H. A. Tarry: J.Phys.D:Appl.Phys.8,1575(1975)): EQU T=(1+u.sup.2).sup.31 1 sin .sup.2 [.theta.(1+u.sup.2).sup.1/2 ](1),
wherein EQU u=.pi.d.DELTA.n/.theta..lambda. (2),
wherein d is thickness of the liquid crystal layer, .DELTA.n is defraction anisotropy of the liquid crystal, .theta. is twist angle of the TN liquid crystal and .lambda. is wavelength of incident light.
Then, by providing .theta.=.pi./2, the value of u which satisfy T=0 of the equation (1) is given by: ##EQU1## wherein m is a positive integer.
In general, the defraction anisotropy .DELTA.n of the liquid crystal has a dependency on the wavelength of the incident light. FIG. 2 shows the wavelength-dependency of the defraction anisotropy .DELTA.n of a liquid crystal, for example, LIXON 9150 manufactured by Chisso Kabushiki Kaisha. FIG. 3 is a graph made by plotting for the example of d=5 .mu.m and d=8 .mu.m from the equation (1) by Gooch-Tarry of a spectral transmittance characteristic for 0 volt impression in a TN liquid crystal cell having the twist angle .theta. of 90.degree..
As shown in FIG. 3, the spectral transmittance characteristic shows about 10% transmittance at its peak in a visible range (400-700 nm) and can not completely stop the light. Accordingly, the cell of d=5 .mu.m shows reddish colors and the cell of d=8 .mu.m shows yellow colors. But the 5 .mu.m thick cell can stop the light around the wavelength of 570 nm and the 8 .mu.m thick cell can stop the light around 440 nm.
As shown in this actual example, when using the TN mode liquid crystal, there is problems of insufficient light stopping and resultant coloring in displaying. Apart from mono-color displaying wherein such insufficient light stopping and coloring is only little problem, these problems induce a great obstacle for full color displaying.
FIG. 4 shows a sectional view of a conventional color liquid crystal display apparatus. As shown in FIG. 4, the apparatus has a color filter having R, G and B color filter elements disposed in a matrices as shown in FIG. 5, and the apparatus has alignment films 6a and 6b formed on the inner wall of the substrate so as to control initial alignment of the liquid crystal at 0 volt impression state. Therefore by impressing a voltage above the threshold voltage V.sub.th across the transparent conductive film 5a and 5b, the molecular alignment of the liquid crystal is changed, so as to modulate light passing through the liquid crystal cell. Accordingly, by impressing appropriate voltages above the threshold value V.sub.th for respective electrodes responding to the R, G, B color filter elements of the picture elements, a full color displaying can be made by red, green and blue addition color mixing method. FIG. 6 shows one example of spectral transmittance characteristic of the color filters of R, G and B color used in this conventional apparatus. In the conventional exmaple, the problems to consider are leak and undesirable coloring of light at 0 voltage impression. Since a contrast ratio is defined as [light transmittance for bright state]/ [light transmittance for dark state], in the apparatus of the conventional configuration the existance of light leaking in the dark state, i.e., 0 volt impression state results in lowering of the contrast ratio.
In the conventional configuration where the thickness d of the liquid crystal layer is uniform for all parts of color picture elements for R, G and B, when for example d is 5 .mu.m, in the elements of the color filters G and R the lights are almost stopped at the 0 voltage impression, while the light cannot be stopped at the elements of the B filter parts as is obvious in FIG. 3 and FIG. 6. Accordingly the apparatus shows blue or violet color as a whole at the 0 voltage impression instead of a perfect black. This phenomenon is a grave obstacle in full color displaying by the color liquid crystal display apparatus.
As can be understood from the Gooch-Tarry's equation (1), as the thickness of the liquid crystal layer increases, (e.g. above about 10 .mu.m ) , the above-mentioned light leakage at 0 voltage impression decreases, and accordingly the coloring at the 0 voltage impression becomes small. However, when the thickness "d" increases, such problems are induced that elongation of response time of the liquid crystal for ON-OFF switching of the voltage impression, decrease of view angle and negative display voltage region as will be mentioned later which induces shift of color by variation of the view angle. Accordingly, such liquid crystal display apparatus becomes quite poor in color performance characteristics.
Since a color liquid crystal display apparatus using the TN mode liquid crystal is expected to have good response speed and wide view angle, the apparatus is liable to be designed with the relation between d and .DELTA.n to fulfil u.perspectiveto..sqroot.3 for green light, namely with as short thickness d as possible. However, when such a thin liquid crystal layer is used, there is a problem that light transmittance for having wavelength of the condition apart from u=.sqroot.3 becomes dominant, and then the display apparatus shows undesirable and unnatural colors.
As far as the liquid crystal layer of uniform thickness for different color parts is used, resolving of the above-mentioned various problems is impossible.

Matsushita Electric Industrial Co., Ltd.


A system for assessing the test effectiveness of a test tool for testing a computer system is described. The computer system is first subdivided into a plurality of functional components. For each of the functional components, a set of numbers is determined, each number corresponding to a plurality of factors indicating the effectiveness of the test tool. Based on the determined numbers, a normalized weight of the set of numbers for each of the functional components is computed. Then, based on the normalized weight for each of the functional components, a component test value for the test effectiveness of the test tool in testing each of the functional components is computed. Based on the normalized weight and the component test value for each of the functional components, an overall test value for the test effectiveness of the test tool in testing the computer system hardware is computed. Finally, the test tool is modified to improve the test effectiveness, based on the component test values and the overall test value. The system could be applied to identify weak areas of test coverage for the purpose of re-allocating coding efforts and resources.

The normal practice in the use of test tools has been in the automatic generation, management and execution of test cases. Current test tools can shorten test duration, or increase the scope of the test by the use of several and possibly overlapping test tools. Test coverage tools are used in software, but are not currently suitable for use on hardware.
Accordingly, it would be desirable to provide a system for assessing the effectiveness of a test tool used to test a computer system, and mathematical modelling can be used to make the assessment.
The following publications provide background for the invention, and are cited in full in the following section. A brief discussion of each follows.
R. E. Skibbe (1) presents a tool (PACE) for evaluating microprograms which can be used to measure testing coverage of microprograms. PACE provides a useful technique for measuring the coverage of of microprograms, or software, but it is highly unsuitable for measuring hardware functions.
K. Woollard (2) discusses verification topics for testing Broadband Networks. The article emphasizes the semi-automatic generation of tests, and the problems associated with the test generation.
E. D. Shockley (3) discusses the BRAVE II tool and test cases for testing and test automation.
G. Van Asten (4) discusses the BRAVE tool for testing and test automation.
R. C. Hatch (5) discusses the development of an integrated test environment, which consists of a test case manager, test case library system, test case migration facility, for the development, execution, storage and migration of test cases.
O. Rafiq (6) investigates the applicability of the Astride Testing Approach by using the ISO Conformance Testing Terminology.
M. S. Abadir (7) provides an overview of a knowledge-based testability insertion guidance expert system for creating complex and testable designs. The system identifies testability problems, formulates a test strategy for the design, and plans the invocations of gate-level test tools.
Unlike our proposed invention, these articles (2-7) do not address mathematical modeling for assessing the test effectiveness of test tools.
N. Vidovic (8) discusses software design and verification. The use of several test tools and software test techniques as well as data collection and analysis are also discussed.
E. B. Holloway (9) discusses the work of the Open System Testing Consortium, which ensures the conformance of test services and the recognition of test results between test members.
C. A. Bering and J. H. Covey (10) discuss the use of test objectives, test documentation requirements, and automated test tools in the testing process.
F. de Jong (11) addresses test pattern generation, the data flow around this generation software, and the format of test vectors in board-level circuit design.
The author presents a program for checking correctness of vectors and PC-based Boundary Scan Testing (BST) validation tool for addressing the needs of designers.
J. F. Faga (12) discusses a process for program (software) understanding (comprehend the logic, flow, and structure of source program code) for the purpose of design recovery, re-engineering, test tools and design tools development, etc.
M. Roberts (13) discusses improvements in the development and use of test tools running under the UNIX Platform by using Windows.
The coverage of these articles (8-13) is different than our invention because they do not address methods for assessing test coverage effectiveness of test tools for testing the hardware and software of computer systems.
None of the mentioned prior art references teaches, claims or even suggests mathematical modelling for assessing the effectiveness of a test tool which is used to test a computer system.
Prior art: Publications and Other
1. R. E. Skibbe, "PACE-A Microprogram Evaluation System," Proceedings of the 15th Annual IEEE Workshop on Microprogramming, Palo Alto, Calif., October, 1982, pp 181-191.
2. K. Woollard, "Verification and Testing," British Telecom Technology Journal, Vol. 11, No. 1, January 1993, pp. 158-167.
3. E. D. Shockley, "Guide to Writing BRAVE II Exercisers," IBM Technical Report TR-54.744, Boca Raton, Fla., unpublished.
4. G. Van Asten, "Multi-Interface Verification Software Process," IBM Technical Report TR-54.716, Boca Raton, Fla., unpublished.
5. R. C. Hatch, et al., "An Integrated Testcase Development and Execution Environment," IBM Technical Report TR-77.0258 Boulder, Colo., unpublished.
6. O. Rafiq, "Astride Testing Approach. Principles, Tools and Carrying Out," Computer Standard Interfaces, Vol. 11, No. 2, 1990, pp. 85-94.
7. M. S. Abadir, "TIGER: Testability Insertion Guidance Expert System," IEEE International Conference on Computer Aided Design," 1989, pp. 562-565.
8. N. Vidovic, "Cross-Development Software Needs Muscle," Electronic Engineering Times, Aug. 16, 1993, p. 46-49.
9. E. B. Holloway, "Open System Testing Consortium," British Telecommunication Technology Journal, Vol. 11, No. 1, January 1993, pp. 153-157.
10. C. A. Bering and J. H. Covey, "Software Testing--Concepts and Approach," IEEE Proceedings of the National Aerospace and Electronics Conference, Vol. 2, 1991, pp. 750-756.
11. F. de Jong, "Boundary Scan Test Used at Board Level: Moving Towards Reality," Proceedings-International Test Conference, 1990, pp.235-242.
12. J. F. Faga, "A Data Model for Program Understanding," IBM Technical Report TR-03.415 Sterling Forest, N.Y., unpublished.
13. M. Roberts, "Protocol Test Tools: Maintaining Quality and Competitiveness," Telecommunications (Int. Ed.) (USA), Vol. 26, No. 11, November 1992, p. 48, 52, 54.

International Business Machines Corporation


In an optical connection board, a first clad layer is formed on a flat surface of a substrate and a core layer is formed on the first clad layer and is extended in a propagation direction of an optical signal. The core layer is covered with a second clad layer. A termination mirror having a reflection face is so buried in the clad layer as to reflect the optical signal guided in the core layer, to the outside of the optical connection board.

1. Field of the Invention
The present invention relates to an optical interconnection circuit board and a method of manufacturing the circuit board. More particularly, the invention relates to an optical interconnection circuit board having an optical waveguide for optically connecting different LSIs at high speeds and to a method of manufacturing the circuit board.
2. Description of the Related Art
Recently, electronic devices as bipolar transistors and field-effect transistors have been improved in terms of their performance. The clock frequency of the LSI has increased so that the LSI may operate at a remarkably high speed. However, the operating speed of a printed circuit board with LSIs mounted thereon is designed to operate at a speed lower than the operating speed of each LSI. The operation speed of the rack on which the printed circuit board is mounted is suppressed to be even lower. This is because the clock frequency must be lowered to prevent the deterioration of signals. In this regard, it should be noted that the transmission loss in the wires, the signal noise and the electromagnetic trouble increase as the operation clock frequency increases. To reduce the deterioration of the signal it is necessary to lengthen the wires that connect the LSIs. In view of this, the operation frequency cannot be raised as high the internal operation clock frequency of the LSI. Even if the LSIs, which are active devices, can operate high speeds, there is no way but decreasing the operating speed of an electronic wiring module.
In views of the aforementioned problem of the electronic wiring module, several optical connection modules for connecting the LSIs have been proposed. The optical connection module virtually has no frequency dependency, in terms of loss in a frequency region from DC to tens gigahertz or more. It has no electromagnetic troubles or causes no noise even if the ground potential change in the wiring path. Therefore, the optical connection module can transmit signals at tens of Gbps is possible. The optical connection module can operate at a very high speed on printed circuit boards or on the rack holding a printed circuit board.
To provide such an optical connection module, it is necessary to connect LSIs by optical waveguides or optical fibers. Generally, the optical connection in an optical connection module is achieved by aligning and connecting substrates, each having a flat optical waveguide, or by aligning and connecting optical fibers. Since it takes much time to align the substrates or optical fibers, the productivity of the optical connection module is inevitably lower that that of the electronic wiring module that comprises LSIs. To mount an electronic element, such as a semiconductor laser, a photodiode or the like, on an optical connection module, a notch is made in the optical waveguide and the electronic element is set in the notch. The position of the notch and the kind of the element set in the notch differ from module to module. This means that optical connection modules need to be designed, one by one.
The substrate of the optical connection module is generally flat. The light input/output part therefore extends at right angels to the substrate. An optical-path angle converter for changing the optical path by 90° is provided in the optical waveguide, and the optical components are mounted on the substrate. However, no optical-path angle converters have been realized, which are highly productive and efficient.
Hitherto, various methods have been practiced to mount the optical components. In one method, the optical waveguide is mechanically cut at 45° to reflect a light beam at right angles. In another method, a 45°-mirror is mounted at an output port of the optical waveguide. The method of cutting the optical waveguide at 45° can be used, but only at the ends of the connection module. A method of cutting the optical waveguide obliquely by dicing or laser process is generally employed. Another method of grinding the optical waveguide obliquely for each substrate is well known.
Of the methods of providing the 45°-mirrors, the method of aligning micro 45°-mirrors with an optical terminal is the simplest. To reduce mechanical arranging process, a new method has been proposed. In this method, the optical waveguide board and the micro mirrors are produced separately and bonded together. (See, for example, Society of Photo-Optical Instrumentation Engineering: SPIE Vol. 3288, p. 79).
FIG. 1 shows the optical waveguide board provided with micro mirrors described in the above document. As FIG. 1 shows, the micro 45°-mirrors 3 are provided on the mirror board 1. Note that reference numeral 15 denotes an optical waveguide board, reference numeral 4 designate an optical waveguide core layer, and reference numerals 2 and 5 represent clad layers. In FIG. 1, the arrows indicate the direction in which optical signals travel. Optical devices, LSIs and the like are mounted on the substrate 15 and electrically connected.
In these methods, an optical beam can undergo orthogonal transform. With the method of cutting the optical waveguide, however, it is difficult to form an optical input/output portion at any position and in any direction in the substrate. If many optical input/output portions are provided, the productivity will decrease. In the method of mounting external mirrors, not only the substrate becomes complicated, but also mounting failure or pollution is likely to occur because these mirrors are mechanically mounted. The problems described above hamper an increase in the productivity of the optical connection modules, rendering it difficult to manufacture highly general-purpose optical connection modules at low cost.
Jan. Pat. Appln. KOKAI Publication No. 2000-114581 discloses a method, in which active devices, such as semiconductor laser, photo diode and driving IC, are buried in the optical interconnection circuit board. The active devices are electrically connected to an electric wiring substrate. The electric-wiring substrate is mounted on the optical connection board. Another method is proposed in Society of Photo-Optical Instrumentation Engineers: SPIE Vol. 3288, p. 133. In this method, the substrate is made rough at one surface to deform its lower clad layer, and a mirror is mounted on the deformed portion.
In the first-mentioned method, the LSI is mounted by ordinary electric connection. An ordinary mounting scheme such as soldering reflow can therefore be applied. However, the active devices are buried in the mounting substrate, the structure can hardly enlarged to tens of centimeters due to thermal distortion, and wiring for the mounting is not suitable for general purpose. In the second-mentioned method, the optical waveguide and electric wiring are formed on the optical connection board, without performing any other treatment. The structure can be easily enlarged, and its mounting wiring pattern can be altered by changing the photolithography mask to another.
FIG. 2 shows the structure based on Society of Photo-Optical Instrumentation Engineers: SPIE Vol. 3288, p. 133. In FIG. 2, reference numeral 1 designates a substrate, reference numeral 2 a cladding layer of the optical waveguide, reference numeral 4 a core layer of the optical waveguide, reference numeral 5 a cladding layer of the optical waveguide, and reference numeral 3 denotes a buried mirror provided directly in contact with the optical waveguide core layer 4. As shown in FIG. 2, the substrate 1 and the cladding layer 2 have an uneven surface. The buried mirror 3 is formed by vapor-depositing metal on a slope corresponding to the border of the unevenness of the cladding layer 2. With this conventional structure, the light wave traveling through the optical waveguide is partially picked up. In the structure of FIG. 2, the intermediate terminal of optical bus functions as an optical tap. Here, the mirror 3 functions as an optical split mirror.
In this conventional structure, the height of the split mirror 3 is less than the thickness of the optical waveguide core layer 4. The split mirror 3 is buried in the optical waveguide core layer 4. Therefore, the mirror 3 splits a part of guided light wave, and the remaining part of the light wave can be distributed to a following optical waveguide to guide the light wave from the split mirror 3. Since the optical waveguide is a multi-mode waveguide, the light wave split by the mirror 3 can mix with the light wave passing over the mirror 3. Hence, optical distribution can be designed easily by simulating the traveling of the light wave. Further, the light wave thus guided can be input to the optical split portion from outside. The basic function as a signal bus can therefore be realized with a simple structure.
However, the substrate 1 and the lower clad layer 3 have an uneven surface in this conventional structure. The core layer 4 inevitably has an uneven surface. The energy loss in the light wave traveling through the optical waveguide is large. That is, the guided light wave produces a mode transformation loss at the border of the unevenness or at a bent portion of the core layer 4. The loss is greater than in a flat optical waveguide. This conventional structure is disadvantageous in that the energy loss in the guided light wave is too large. Since the buried mirror 3 is designed to achieve partial splitting, it, used as an optical path transformation mirror for optical transmission, reduces the opening area of a light incident section to a value less than the sectional area of the optical waveguide. Assume that vertical splitting efficiency of the buried type mirror 3 is 10% ( 1/10 split). Then, the sectional area of the optical transmission beam needs to be 1/10 the sectional area of the optical waveguide.
Generally, converging light beam results in an increase in the divergent angle of the beam. In view of this, it is no use to converge the beam so much that an angle exceeds a numeral aperture of an optical waveguide. Here arises the problem that optical coupling efficiency of the optical transmission portion may fall in some cases. This problem cannot help but be accepted as necessity. Nonetheless, it leads to an energy loss in the optical transmission of a one-way distribution of signal. Further, at an end portion of the optical waveguide, the guide light wave other than split light may emerge from the waveguide or may be reflected in an opposite direction. In this case, crosstalk will occur with other optical waveguide, or multi-reflection will take place in the optical waveguide. This generates a delay noise signal.
In the conventional structure described above, the split mirror or the buried mirror 3 is inclined due to deformation of the substrate. It is therefore required that the unevenness be made in the substrate and, hence, in the lower clad layer, too. This structure imposes restrictions on the material, size and the like of the substrate material. Consequently, the process of controlling the unevenness and the depth therefore is complicated, and the manufacturing method is difficult to control. To avoid this problem, the substrate may be made by molding. This method can indeed applied to mass-produce the same substrates. However, it requires a large initial investment for the mold, and the wiring pattern cannot be altered easily. In other words, this method is not a general-purpose one.
As described above, in the optical connection board for optically connecting LSIs, a highly practical 90°-optical path transform mechanism has not been yet realized. The productivity cannot be raised, and the manufacturing cost cannot be lowered.

Optical interconnection circuit board and manufacturing method thereof


A piezoelectric ceramic plate which is slightly deformed by firing, includes a plate-shaped substrate, and an electronic component. The piezoelectric ceramic plate has a pair of main surfaces, a pair of opposing first side surfaces, and a pair of opposing second side surfaces. The pair of first side surfaces are baked surfaces, and the distance between the pair of first side surfaces measured at the center in the longitudinal direction is denoted by Lc and the distance between the pair of first side surfaces measured at ends in the longitudinal direction is denoted by Le. The ratio of the difference ΔL between Le and Lc to Lc (ΔL/Lc) is 1.0% or less. The piezoelectric ceramic plate is suitably used as a piezoelectric ceramic plate having an area of each of the main surfaces of 360 mm2 or more and a thickness of 150 μm or less.

Piezoelectric ceramic plates are used for a variety of electronic components, such as a piezoelectric actuator, which utilize, as a mechanical driving source, displacement or force generated via a piezoelectric phenomenon. With broadened use of piezoelectric actuators, multi-layer piezoelectric actuators from which larger displacement or larger generated force can be obtained at lower voltages have become increasingly used.
Since conventional piezoelectric ceramic plates develop significant deformation (variation in shrinkage) after firing, such piezoelectric ceramic plates are subjected to processing, such as cutting and polishing, after firing in order to control the shape and dimensions of the piezoelectric ceramic plates into prescribed ranges (see, for example, Patent Literature 1).

Piezoelectric ceramic plate, plate-shaped substrate and electronic component


This invention relates to a semi-batch process for producing low molecular weight polyoxyalkylene polyols. These polyoxyalkylene polyols are characterized by hydroxyl numbers of from 200 to 500. In accordance with the invention, the first alkylene oxide block used to activate the DMC catalyst comprises from 50% to 100% by weight of propylene oxide and from 0% to 50% by weight of ethylene oxide; and the second alkylene oxide block comprises from 50% to 100% by weight of propylene oxide and from 0% to 50% by weight of ethylene oxide. A continuously added starter is present. Optionally, a third alkylene oxide block can be added. The addition of the second alkylene oxide block and of the third alkylene oxide block when present is completed with a space time yield of greater than or equal to 250 kg/m3/hr.

The present invention relates to a semi-batch process for the production of low molecular weight polyoxyalkylene polyols. This semi-batch process oxyalkylates one or more starters in the presence of a DMC catalyst in which the alkylene oxide feed is completed with a space time yield of greater than or equal to 250 kg/m3/hr.
The production of low molecular weight products is important as these can be used directly to replace products made using conventional KOH technology or these can be used as starters to make long chain IMPACT (DMC) or KOH products. One of the challenges of making low molecular weight products with DMC catalysts is deactivation of the catalyst. It is well known that deactivation of the DMC catalyst can be resolved by increasing the catalyst concentration. This is not desirable, however, due to the expense of the catalyst. It is preferred to maintain a constant catalyst level of 60 ppm or lower. It is also preferred to maintain the reaction temperature at 130° C. or lower to minimize potential negative effects of reaction temperature such as color formation.
One advantage of double metal cyanide catalysts is that they do not promote the rearrangement of propylene oxide into propenyl alcohol which acts as a monofunctional initiator in propylene oxide polymerization. The presence of propenyl alcohol promotes the formation of monoalcohols which are an impurity in the process.
Another advantage of double metal cyanide catalysts includes the ability to leave the catalyst residue in the product. This results in lower production cost since the catalyst residues do not have to be removed from the polyoxyalkylene polyol prior to use. This is also another reason that it is desirable to minimize the amount of catalyst used.
While double metal cyanide catalysts provide numerous advantages in preparing polyoxyalkylene polyols, there are, unfortunately, some disadvantages to this type of catalysis. These disadvantages include the tendency of the catalyst to deactivate in the presence of high concentrations of hydroxyl groups, the inability to polymerize in the presence of low molecular weight initiators such as glycerin, and the fact that, in addition to the desired product, DMC catalysts produce a small quantity of a very high molecular weight (i.e. at least 100,000 MW and higher) polymer. This high molecular weight polymer is commonly referred to as high molecular weight tail. High molecular weight tail causes difficulties with the foaming process when reacting a polyol with a polyisocyanate to produce a polyurethane foam.
There have been numerous efforts over the years to improve and extend double metal cyanide catalysis to enable effective oxyalkylation of low molecular weight starters such as glycerin, and to produce low molecular weight polyoxyalkylene polyols. The acidification of starters is one method found to be effective. Another method is to use starters with ultra-low water content.
Low molecular weight or high hydroxyl number polyoxyalkylene polyols are characterized by a high percentage of the starter used to make the final product. As an example, a 400 MW, glycerin based polyoxyalkylene polyol contains 23% by weight of glycerin and 77% by weight of alkylene oxide (weight percent based on the total product); whereas a 3000 MW, glycerin based polyoxyalkylene polyol contains 3% by weight of glycerin and 97% by weight of alkylene oxide (weight percent based on the total product). The 400 MW product requires an overall starter to alkylene oxide ratio of 0.3 while a 3000 MW product requires an overall starter to alkylene oxide ratio of 0.03. As used herein, the starter is the total weight of starter required and the alkylene oxide is the total weight of alkylene oxide required. The higher ratio of starter to alkylene oxide or higher concentration of starter required for the low molecular weight polyoxyalkylene polyols presents challenges in a DMC catalyzed process because of the tendency of the starters to inhibit the activity or deactivate the DMC catalyst. This reduction in activity or deactivation of the DMC catalyst is measured by a pressure increase in the semi-batch reaction caused by elevated free oxide concentration. Pressure increases are often observed after the low molecular starter is introduced to the reactor of a semi-batch process using a Continuous Addition of Starter (CAOS) approach to make low molecular weight polyoxyalklyene polyols. Typically, in such an approach the DMC catalyst is first activated in the presence of an initial starter or heel and reacted with alkylene oxides before the continuous starter is introduced. This is, known as a Pre-CAOS build ratio. The initial pressure increase observed after the introduction of the CAOS feed demonstrates that the DMC catalyst is not fully activated or becomes partially inhibited by the starter introduction. The Pre-CAOS build ratio is part of the process that allows the catalyst to become activated, and thus prevents the batch from completely deactivating. As the reach of DMC technology is extended to products having lower and lower molecular weights, one of the most significant hurdles to be overcome is the tendency of the system to deactivate via elevated free oxide content soon after a high instantaneous starter/alkylene oxide ratio feed commences, and before the catalyst has become fully active. Although extending the Pre-CAOS build ratio will help prevent this, it then becomes necessary to compensate for the delay by feeding at an even higher instantaneous starter/alkylene oxide ratio once the CAOS feed commences as the denominator has decreased. The instantaneous ratio is defined by the total continuous starter weight over the alkylene oxide weight fed during the continuous starter feed.
The second area where the pressure can increase quicker than usual demonstrating an increase in elevated free oxide concentration and thus a reduction in the catalyst activity is at the end of the CAOS feed. This indicates a gradual loss of catalyst activity during the main portion of the oxyalkoxylation as the catalyst concentration in the reaction media decreases.
Thus, a need exists for a method to accelerate the rate at which the DMC catalyst becomes active and a method to maintain catalyst activity. It has recently been discovered that a partial EO co-feed and/or increase in feed rates of alkylene oxides appear to do just that. The fact that EO and/or increased feed rates can accelerate DMC catalyst activation may lead to the development of processes for low molecular weight polyols that do not require special raw material handling (such as ultra-low water levels in the CAOS feeds) which can be difficult to meet on a commercial scale.

Process for the production of low molecular weight polyoxyalkylene polyols


An apparatus for determining at least one size parameter of an object whether it is moving or at rest comprises an optoelectronic measuring system, which comprises an evaluating unit and transmitting and receiving means, which are disposed in a measuring plane that extends substantially at right angles to the longitudinal axis of the object. The measuring plane extends in a measuring portal, which comprises at least two measuring beams, which include a predetermined angle with each other. Each of said measuring beams has a side face which faces said measuring plane and on said side face is provided with at least one row of receiving elements. Associated with each of said rows of receiving elements is a transmitting element, which is disposed in the measuring plane at a fixed distance from the associated measuring beam and is adapted to be periodically activated to emit a fanlike light beam, which is incident on the receiving elements of the associated row thereof.

1. Field of the Invention
This invention relates to an apparatus for determining at least one size parameter of an object whether it is moving or at rest, which apparatus comprises an optoelectronic measuring system, which includes light transmitting and receiving elements disposed in at least one measuring plane that is substantially at right angles to the longitudinal axis of the object, and also includes an evaluating unit, wherein the measuring plane is defined by a measuring portal comprising at least two support beams for the light receiving elements of the measuring system, which include a predetermined angle with each other.
2. Background of the Invention
Austrian Patent Specification 351,282 discloses an apparatus for determining and/or monitoring at least one size parameter of an object whether it is moving or at rest, which apparatus comprises line cameras disposed in two planes, which include an angle of 90.degree., which cameras instead of a film comprise a surface provided with rows of photodiodes for generating an electronic image of the shadow of an object which is disposed in front of a bright background and viewed through an optical system.
That apparatus is rather expensive owing to the provision of the line cameras and has the disadvantage that in dependence on the position of the object being viewed the image of its shadow may be unsharp so that the accuracy of the measurement may adversely be affected.
German Patent Publication 2,019,290 and Published German Application 2,127,751 disclose apparatuses in which the object to be measured is periodically scanned so that an overall image of such object can never be generated at any specific instant. Those apparatuses have also the disadvantage that they require light transmitters or mirrors which are mechanically moved.
Other known apparatuses comprise support beams, in each of which a row of infrared-emitting diodes are closely and regularly spaced apart in a row and an infrared photodiode is associated with each of said rows and is disposed in the measuring plane and centered with respect to the support beam. The infrared-emitting diodes are consecutively activated together with the associated infrared photo-diode after short, equal intervals of time by an evaluating unit.
That apparatus for a periodic scanning has the disadvantage that the adjustment of the infrared-emitting diodes takes a long time and can be effected only with expensive means, such as an oscillograph. Besides, the signals generated by the infrared photo-diodes are relatively weak and must be amplified before they can be processed further. But such amplification may result in a drifting or change or the parameter as a function of time and temperature so that the result of the measurement may be distorted.

Apparatus for determining at least one size parameter of an object whether it is moving or at rest


The invention is directed to a power tool apparatus such as a table saw which includes a housing having a table top with an appropriate opening for a motor driven tool. Pivotally mounted within the housing is an assembly which in the disclosed embodiment includes a frame having a subassembly pivotally mounted therein. A subassembly includes the tool, such as a saw blade, and the means for driving same. A first control includes a lever connected to the subassembly for pivoting same. The pivotal movement effected by the lever allows for quick and coarse setting of the tool at a desired elevation with respect to the tabletop. The control lever further includes a locking arrangement disposed thereon which is manipulatable by the same hand used to coarsely set the tool elevation. The locking arrangement secures the lever to the frame at the desired coarse setting.. A second control means likewise operable by the same hand of the operator, is connected to the subassembly, whereby the subassembly is pivoted independently of the first control. This second control provides a vernier adjustment of the tool. The assembly can be pivoted about its pivot mount in the housing in order to change the relative angle of the tool to the tabletop so that bevel cuts can be made.

Elevating and tilting mechanisms of the general nature described hereinafter have typically employed worm screw arrangements. Such units are described in U.S. Pat. Nos. 2,850,054, 2,852,047 and 2,873,773. Although these units provide for an accurate setting of the tool in relation to the table top, the time necessary for the operator to arrive at the required tool elevation and bevel angle is often times unduly lengthy.
Further, these type mechanisms are generally intricately machined, and thus expensive, cumbersome and typically not conducive for on-site work by contractors or available for the homeowner for use around the house.
Rapid-set, lever-operated, elevating and tilting devices are also known. See, for example, U.S. Pat. Nos. 2,704,560; 2,719,547 and 3,670,788. Although the units described in the aforementioned patents have lever-operated arrangements, none of those cited above disclose a locking mechanism which can be manipulated by the same hand of the operator used to set the elevation of the blade. Further, none of those identified, suggest the inclusion of a vernier adjustment of the tool.
Finally, applicant is aware of a table saw presently marketed overseas, which includes a lever-operated, elevating mechanism having means for locking the lever to the housing at the desired blade elevation setting. Further, this table saw includes a vernier adjust feature which is disposed on the lever and activated through rotation of the lever grip.
The table saw also includes means for varying the angular relationship between the tool and the work surface. However, in this table saw, it is the work surface table portion thereof which is pivotally mounted on the housing. The fact that the work surface tilts, limits the application of such a machine in that relatively long pieces of lumber and the like can't be cut at larger bevel angles because the floor on which the table saw stands, acts as an obstruction. This generally precludes application of such a device to on-site work by the small contractor or homeowner and, hence, limits its general application.
It is, therefore, a primary object of this invention to provide a power tool apparatus which allows for one-hand, coarse and vernier adjustment of the tool elevation setting and which further provides a lever-operated, tilt mechanism wherein the tool support assembly is pivoted relative to a stationary, horizontal work surface.
It is still a further object of this invention to provide a power tool apparatus which achieves the accuracy of worm gear type units, but which provides quick setting of the elevation angle of the tool.
It is yet another object of this invention to provide a locking mechanism, disposed on the elevation setting lever, which is manipulated by the same hand.
It is yet a further object of this invention to provide a power tool apparatus which employs a relatively simple, vernier adjust mechanism.
It is still another object of this invention to provide a power tool apparatus which because of its relatively simple design, is mass producible at a cost which makes it readily available to the small contractor or homeowner.
It is yet another object of this invention to provide in one embodiment, a compact, portable apparatus which is aptly suited for practically all types of on-site work encountered by the small contractor or homeowner.
It is still a further object in one application of the invention to provide the above-mentioned power tool apparatus in the form of a table saw which is low cost, and which meets the needs of the small contractor or homeowner.


A device for cutting a strip fed continuously on a roller through a cutting station where a series of at least partial transverse cuts are made successively in the strip by a cutting unit. On the cutting unit, a hollow rotary drum receives a laser beam emitted by a laser source, and focuses the beam at at least one point which, as the drum rotates, moves along an annular trajectory, the plane of which intersects the route of the strip at the cutting station and forms a given angle with a line intersecting the route of the strip.

The present invention relates to a device for transversely cutting lengths of a strip traveling continuously along a predetermined route.
For cutting lengths of sheet material, a strip of the material traveling continuously along a predetermined route is usually cut transversely and at least partially by feeding the strip through a cutting device comprising two rollers, one fitted with a blade and the other with a cutting block or anvil, and by rotating the rollers in opposite directions so that the blade cooperates at regular intervals with the cutting block or anvil for cutting the strip.
One drawback of known cutting devices of the aforementioned type is that they are relatively noisy, due to the blade necessarily striking the cutting block or anvil when cutting the strip. Moreover, continual contact between the blade and the cutting block or anvil results in rapid wear and, consequently, frequent sharpening of the blade.

Device for transversely cutting lengths of a strip traveling continuously along a predetermined route


A heterojunction bipolar transistor (HBT) is disclosed that includes successive emitter, base and collector and sub-collector epitaxial layers and emitter, base and collector contact metals contacting the emitter, base and sub-collector layers respectively. A passivation material is included that covers the uncovered portions of the layers and covers substantially all of the contact metals. The passivation material has a planar surface and a portion of each of the contact metals protrudes from the surface. Planar metals are included on the planar surface, each being isolated from the others and in electrical contact with a respective contact metal. A method for fabricating an HBT is also disclosed, wherein successive emitter, base, collector and sub-collector epitaxial layers are deposited on a substrate, with the substrate being adjacent to the sub-collector layer. The epitaxial layers are etched to provide locations for contact metals and emitter, base and contact metals are deposited on the emitter, base and sub-collector epitaxial layers, respectively. A self-alignment material is deposited on the surface of the substrate around the epitaxial layers and a planarization material is deposited on and covers the top surface of the HBT. The planarization material is then etched so it has a planar surface about the same level as the surface of the self-alignment material and the contact metals protrude from the planar surface. The planar metals are then deposited over the protruding portions of the contact metals.

1. Field of the Invention
This invention relates to semiconductor devices, and more particularly to planarized contacting of semiconductor devices such as high power heterojunction bipolar transistors (HBTs).
2. Description of the Related Art
HBTs are described in general in Wang, Introduction to Semiconductor Technology: GaAs and Related Compounds John Wiley & Sons, 1990, pp. 170-230. Some of the advantages of HBTs over other transistors such as FETs include; short transition times because of their vertical structure, higher current handling capability per unit chip area, which contributes to higher output drive capabilities, and increased transconductance.
There is a continuing need to develop integrated circuits and components, including HBTs, which operate at higher frequency or speeds, with reduced power. This design goal places a greater emphasis on increased component integration and packing density, which results in decreased feature sizes, increased interconnection complexity and use of new or specialized materials.
One of the concerns in fabricating semiconductor devices such as HBTs is reliably making electrical contact to the different epitaxial layers (emitter, base and collector layer for HBTs), and isolating devices electrically by eliminating or rendering inactive the epitaxial layers outside of the transistors. In fabricating conventional HBTs, epitaxial layers are grown vertically to form the HBT's active layers. To contact the HBT's emitter layer a contact metal can be deposited on the device's top surface, which is generally an emitter contact layer. To contact the base layer, the emitter contact layer and emitter layer are etched (except under the-emitter contact) to provide a surface on the base layer for depositing a contact metal. To contact the collector layer, portions of the emitter contact layer, emitter layer, base layer and collector layers are etched to provide a surface on a sub-collector layer for depositing the contact metal.
Before electrical connection to the contact metals, conventional HBTs are covered with a passivation material. The emitter, base and collector metals are then contacted through the passivation material, by etching a via pathway through the passivation material down to each contact metal. A conductive material is then deposited in the etched areas to form conductive vias to the contact metals. Electrical connection is made to the HBT's active layers by connection to the conductive vias.
One disadvantage of this technique is that it cannot be used to reliably contact high speed HBTs. To increase the speed of HBTs, the emitter becomes smaller and the size of the emitter correlates to the size of its contact metal. As the emitter is reduced, a point is reached where the emitter metal cannot be reliably contacted by using conductive vias. The resolution and alignment limits of lithography and etch systems limit how small the device features can be for HBTs. The smallest resolution for etching a via though polymide or BCB over an emitter metal is approximately 0.5 μm. The emitter should be 0.2 μm wider than the width of the via to provide a margin of error in case the via is not perfectly aligned over the emitter metal. Accordingly, the smallest the emitter can be is approximately 0.75 μm wide.
Another concern is that for smaller emitters the via etch may not align with the emitter metal. This can result in the etch extending beyond the emitter metal to the epitaxial layer. When the via etch is filled with the conductive material to form the via, the conductive material can form a short to the epitaxial material that bypasses the emitter metal, emitter contact layer and emitter layer. This naturally results in a greater number of fabrication errors, making the HBTs less reproducible.
Planarization has been used to remedy surface topologies that can create problems for a semiconductor device's performance and survivability [See U.S. Pat. No. 4,996,165 to Chang et al.]. Variations in feature height, topography or morphology can lead to stress in subsequently deposited layers or materials and height variations in one layer can make precise control of the dimensions of subsequent layers difficult. The features of a semiconductor device are formed by depositing a layer of photoresist on an upper layer of the structure and developing it in a desired pattern. After development and etching, some photoresist remains on the upper surfaces of the features. A layer of dielectric material such as SiO is deposited across the semiconductor structure to a depth substantially the same as the height of the tallest features. The remaining photoresist is then removed along with the dielectric deposited thereon. A layer of polymide is deposited on the upper surface of the SiO and features, and extends into depressions between to control the height variations.

Heterojunction bipolar transistor with dielectric assisted planarized contacts and method for fabricating


This specification discloses a method of and an apparatus for controlling electrophotographic images comprising the steps of detecting the contrast voltage between the surface potentials of the light and dark regions of an electrostatic image formed by the electrophotographic image formation process by taking the difference therebetween, modifying the charging conditions so that the detected contrast may assume a predetermined value, and realizing the substantial background region potential at a predetermined level which would not create fog when said electrostatic image is developed into a visible image, substantially without varying the modified contrast.

1. Field of the Invention
This invention relates to a method of and apparatus for stabilizing images in electrophotography. More particularly, it relates to a method of and apparatus for measuring the surface potential of light and dark regions of an electrostatic image and detecting the difference or contrast between said surface potentials to thereby stabilize the image.
2. Description of the Prior Art
It is well known that electrophotography is a method whereby charge and a light image are applied to a photosensitive medium to form thereon an electrostatic latent image corresponding to the light image and imparting powder or liquid developer to such a latent image to visualize the latent image. This method has been widely put into practice as office copiers. However, the image formed by the machine may be unstable due to various factors and are not sufficiently satisfactory to the users. As typical factors for the unstability of the image, mention can be made of the deterioration of the photosensitive medium and fluctuations of charging, usually of corona charger due to temperature and humidity. These fluctuations can be detected by measuring the surface potentials in the step of electrostatic image formation which is an intermediate step of the image formation process, and it is known to change the various conditions for the electrostatic image formation in accordance with the detection signal to thereby form a stable electrostatic image.
For example, U.S. Pat. No. 2,956,487 discloses a method in which a probe is disposed in opposed relationship with latent image to thereby effect sensing signal which is a function of the color value of the latent electrostatic image area to thereby stabilize the developed image. U.S. Pat. No. 3,604,925 discloses an apparatus for automatically controlling the amount of electrostatic charge applied to a plane by controlling the potential applied to a corona wire. U.S. Pat. No. 3,788,739 discloses measurement of the surface potential by a probe which is positioned only in the position of the area which is always light struck, and comparison of the surface potential to a fixed reference in order to provide a control signal for compensation in an electrophotographic reproduction device. Further, U.S. Pat. No. 4,000,944 discloses a built-in electrode at the end of a photoreceptor and a probe disposed in opposed relationship therewith to thereby detect the amount of charging effected by a charger and to control so that the charge may be a desired charge on the drum photoconductive surface.
None of such prior art techniques is directed to the detection of the surface potentials of light and dark regions of an electrostatic image and detection of the difference between these surface potentials to thereby directly detect the contrast of the electrostatic image.
In our copending U.S. Patent Application Ser. No. 832,944 (German Patent Application No. P27 41 713.6; British Patent Application No. 38136/77; French Patent Application No. 77/28016), there is disclosed a method of stabilizing an electrostatic latent image which includes the steps of measuring the dark region potential and the light region potential on the photosensitive medium, comparing the thus measured values with respective predetermined reference potential of the light and dark regions, and when the differences thereof are not within the allowable predetermined ranges, then controlling the necessary factors such as energy source of chargers.

Method of and apparatus for stabilizing electrophotographic images