A correlated quadruple sampling processor for improved signal-to-noise ratio in the output of a charge-coupled device (CCD) is comprised of: switching means for momentarily clamping a CCD signal line at a first reference level A before a CCD data pulse and then obtaining a first data sample B with respect to the reference A during a CCD data pulse, and storing the positive sample B-A; switching means for momentarily clamping the CCD signal line a second time at the level C during the presence of the CCD data pulse and then obtaining a second data sample D with respect to the reference level C after the CCD data pulse, and storing the negative sample D-C; and means for obtaining the difference between the stored samples +(B-A) and -(D-C), thus increasing the net signal amplitude by a factor of about 2 while the noise would be increased by only a factor of .sqroot.2 since there will be no correlation in the noise between the double samples +(B-A) and -(D-C) effectively added.

This invention relates to a method and apparatus for sampling data pulses, such as at the output of a charge-coupled device (CCD), and more particularly to improving the signal-to noise ratio in the sampled data.
The development in recent years of charge-coupled semiconductor devices as a result of the MOS-FET technology has led to making analog data registers practical. An article by Gilbert F. Amilio entitled "Charge-Coupled Devices," pages 23-31 in Scientific American, Volume 230, No. 2, February 1974 explains the structure and analyzes operation of such a charge-coupled device (CCD). Another teaching of such devices can be found in U.S. Pat. No. 3,814,955 issued to Yokichi Itoh et al in 1974. Briefly, a CCD consists of a silicon dioxide layer deposited on a silicon substrate material. A plurality of metal transfer electrodes are deposited on the silicon dioxide layer. In N-channel devices, an N-material input diode is formed in the P-type silicon substrate to provide a diode charge-coupling into the device, and an N-material output diode is formed in the P-type silicon substrate to provide a diode charge-coupling out of the device, or a floating gate can be used to sense the charge. By pulsing the transfer electrodes in sequence, it is possible to move potential charges of minority carriers along the surface, or in a buried channel of the silicon substrate. Packets of electrons may be transferred into and out of potential wells of these charge-coupled devices virtually intact, and from potential well to potential well and out through the output diode.
Charge-coupled devices have been used not only in implementing radar data processing components, but also more recently in image sensing elements in a matrix for a full frame of image picture elements (pixels). A major advantage of charge-coupled devices is that once a frame has been stored as charge packets proportional to light intensity of the pixels, they may be read out serially from one CCD by shifting the last row out serially, and shifting the rows down in parallel, or simply queuing all of the rows for full serial-shift readout. In either case, a CCD is read out in response to a clock pulse from a stable source used for synchronization in a CCD data processing system. The problem has been achieving a sufficiently high signal-to-noise ratio to make CCD imaging effective for very faint image sources, such as in sensing stellar visual images. The output of CCD systems is conventionally obtained by a sampling technique using a double sampling technique.

CCD Correlated quadruple sampling processor

Frosch; Robert A. Administrator of the National Aeronautics and Space Administration, with respect to an invention of


An apparatus to support a rotor of a turbine engine disposed upon a support surface is disclosed. The apparatus includes a housing, a rotor support bearing disposed within the housing, and a support leg in operable communication with the housing and in direct structural connection with the support surface.

The present disclosure relates generally to turbines, and particularly to turbine rotor supports.
Current gas turbine engines utilize a bearing to support a rotor therein. The bearing is disposed within a bearing housing that is attached to an inner structure of an exhaust frame. The inner structure of the exhaust frame is located interior to an annular flow area of exhaust gases and is connected to an outer structure located exterior to the annular flow area of the gas turbine via a plurality of struts. The exhaust frame, including the inner and outer structure and struts, are made from structural steel and support the rotor and provide stiffness to the bearing housing. Each strut that projects from the inner structure to the outer structure creates an aerodynamic obstacle to a flow of exhaust, and an accompanying contribution to efficiency loss. Accordingly, an engineering compromise exists between rotor support stiffness and operational efficiency. Further, because the structural steel is not capable of withstanding turbine exhaust temperatures, cooling air is generally required. The cooling air is often provided via auxiliary blowers that are powered by the engine and therefore result in further engine efficiency losses.
Accordingly, there is a need in the art for a turbine rotor bearing support arrangement that overcomes these limitations.

Turbine rotor support apparatus and system


3,7-Dimethyl-2,6-octadien-1-al of formula I is prepared continuously by: ##STR1##. thermally cleaving, in the presence or absence of an acid catalyst, 3-methyl-2-buten-1-al diprenyl acetal of formula II: ##STR2## PA1 thereby eliminating 3-methyl-2-buten-1-ol of formula III and yielding cis/trans-prenyl 3-methylbutadienyl ether of formula IV: ##STR3## PA1 thermally rearranging the resultant butadienyl ether of formula IV thereby yielding 2,4,4-trimethyl-3-formyl-1,5-hexadiene of formula V: ##STR4## PA1 subsequently rearranging intermediate (V) thereby yielding citral product of formula I, which comprises: PA1 as the reaction proceeds, continuously distilling the reaction mixture thereby continuously removing prenol, which is formed by degradation of acetal II, and the intermediates of formula IV and V and any citral product which is formed during the reaction; and PA1 thermally rearranging said intermediates of formula IV and V at a temperature of 100-200.degree. C. in the absence or presence of said prenol to form citral product.

1. Field of the Invention
The present invention relates to an improved process for preparing 3,7-dimethyl-2,6-octadien-1-al (citral) by thermal cleavage of 3-methyl-2-buten-1-al diprenyl acetal.
2. Description of the Background
Disregarding the improvements according to the invention, this reaction has already been disclosed in its essential features, Inter alia, by DE 24 11 530 and EP 210 074 B1.
This is a highly complex reaction which proceeds via three stages, as follows from the reaction diagram below.
1. Thermal cleavage of the acetal of the formula II into 3-methyl-2-buten-1-ol (prenol) of the formula III and the cis/trans-prenyl 3-methylbutadienyl ether (dienyl ether) of the formula IV ##STR5## PA0 2. Thermal rearrangement of the dienyl ether of the formula IV in a Claisen rearrangement to give 2,4,4-trimethyl-3-formyl-1,5-hexadiene (formylhexadiene) of the formula V ##STR6## PA0 3. Thermal rearrangement of the dienyl ether of the formula V in a Cope rearrangement to give the desired citral of the formula I ##STR7##
Citral is used as a scent and, furthermore, is of great importance as a starting material for other scents, such as geraniol, and as a starting material for vitamins, for example vitamin A.
Since not only the starting compound of the formula II but also the desired citral, the byproduct prenol and the citral precursors of the formulae IV and V are sensitive substances which can react further in an undesirable manner, the preparation of citral initially succeeded only with yields of from 60 to 70%. Better citral yields by far were obtained, even on an industrial scale, in accordance with the process of EP 0 021 074 B1. This describes a process for preparing citral from the acetal of the formula II, which comprises continuously distilling off from the reaction mixture, during the reaction, the prenol formed as byproduct. The citral and the citral precursors of the formulae IV and V are retained in the reaction mixture in this case by a distillation tower. The continuous removal of the prenol from the reaction mixture increased the citral yield to about from 85 to 90%. To increase the citral yield further, in EP 0 021 074, in addition, the conjoint use of a substance having a boiling point between that of prenol and that of citral and the citral precursors of the formulae IV and V (what is termed the intermediate boiler) was recommended. This measure increased the citral yield to approximately 95% of theory.
A disadvantage of the process described, which is very good per se, is that the process is only suitable for a batchwise procedure and requires long residence times (about 6 hours) and therefore large apparatuses. A further disadvantage of the known process is that an auxiliary, that is to say the intermediate boiler, must be introduced into the system, which means additional resources for metering the auxiliary, for monitoring its concentration and removing it.


Digital processing of a 525 line N.T.S.C. color television signal is achieved by digitizing (40) with a sub-Nyquist sampling frequency f.sub.s which has a mean value 2 f.sub.sc .+-.1/2 f.sub.F, or more generally m f.sub.L .+-.(p+1/2) f.sub.F (where f.sub.sc, f.sub.L and f.sub.F are the subcarrier, line scan, and field scan frequencies, and m and p are integers). Conveniently the sampling frequency is exactly 2 f.sub.sc during each field and suffers a 180.degree. phase shift between fields. After processing, the signal is converted back to analogue form (50) and, to remove alias components, is comb filtered (30) over the frequency range f.sub.s -f.sub.v to f.sub.v (where f.sub.v is the maximum video frequency in the original signal) by averaging across a 262 line delay (24'), or more generally a delay of a field minus half a line. Preferably a second comb filter (10) is included before the digitizer (40); the two filters (10, 30) are then so arranged that the overall delay suffered over the whole frequency range is substantially the same. Digital comb filters can be used in which case the filters and converters are reversed in position and the initial sampling is at twice the required frequency f.sub.s. Improved diagonal luminance and vertical chrominance resolution is obtained with stationary pictures, and alias components are reduced.

This invention relates to the processing of N.T.S.C. colour television signals in digital (e.g. pulse code modulated) form, In particular the invention relates to methods of and apparatus for generating a digital N.T.S.C. colour television signal from an analogue composite N.T.S.C. signal, and regenerating an analogue N.T.S.C. signal from such a digital signal.
It is known that in general where a signal is sampled, a certain minimum sampling frequency is required if all the information conveyed by the signal is to be correctly transmitted. This minimum frequency limit is known as the Nyquist limit, and, for a baseband signal, is equal to twice the highest frequency component in the signal. Any frequency component f.sub.p in the signal will combine with the sampling frequency f.sub.s to generate a component of frequency f.sub.s -f.sub.p. As long as the sampling frequency f.sub.s is at least twice the highest signal frequency f.sub.v, all the components f.sub.s -f.sub.p will be of frequency higher than f.sub.v and can be removed by low-pass filtering. However, if f.sub.s falls below 2 f.sub.v, then some of the components f.sub.s -f.sub.p will fall in the signal frequency band. These unwanted frequency components are called `alias` components.
For transmitting PAL colour television signals, the use of sub-Nyquist sampling frequencies has been described in British patent specification Nos. 1,511,230 and 1,524,749 and 1,580,724. The techniques there described rely on the particular format of the PAL system, and furthermore alias components generated by the PAL chrominance signal must be allowed to pass through a comb filter in the receiver, whereas with N.T.S.C. signals the chrominance alias components should be rejected by this comb filter.
N.T.S.C. signals have proved to be more difficult to digitise with a sub-Nyquist frequency, even in the light of the methods successfully proposed for PAL. For transmitting N.T.S.C. colour television signals, it has been proposed by JOHN P. ROSSI in a paper entitled "Sub-Nyquist-Encoded PCM NTSC Color Television" published in SMPTE Journal Vol.85, No.1, January 1976, pages 1 to 6, to take advantage of the fact that the liuminance and chrominance components tend to cluster around specific frequencies related to the line frequency f.sub.L. That is, the luminance components tend to cluster around integral multiples of the line frequency, i.e. frequencies given by kf.sub.L where k is an integer, and the chrominance components tend to cluster around odd integral multiples of half the line frequency, i.e. frequencies given by (k+1/2) f.sub.L. Rossi proposes the use of a sub-Nyquist sampling frequency of the form (m.+-.1/4)f.sub.L, where m is an integer, together with a comb filter at the receiver. This filter is arranged to remove all frequencies above the highest video frequency f.sub.v, to pass all frequencies below f.sub.s -f.sub.v, where f.sub.s is the sampling frequency, and to act as a comb filter in the range f.sub.s -f.sub.v to f.sub.v. The comb filter response has nulls at frequencies given by (n.+-.1/4)f.sub.L, where n is an integer, thus removing the highest energy alias components, and has minimum attenuation at frequencies given by nf.sub.L /2, which are the central frequencies for the clusters of wanted luminance or chrominance components. Such comb filtering can be achieved by combining video signals from alternate (not adjacent) time sequential television lines, i.e. lines separated by two line scan periods.
With Rossi's sub-Nyquist process, wanted high frequency components occurring at frequencies given by (n.+-.1/4)f.sub.L are removed by the comb filter, but they generate alias components which pass through the comb filter as they occur at frequencies given by nf.sub.L /2. A further improvement in the ratio of wanted-to-alias components is obtained by removing wanted components at (n.+-.1/4)f.sub.L prior to sampling by means of a second comb filter similar to that described above.
As described by Rossi, preferred sampling frequencies for this method of sub-Nyquist sampling are 2 f.sub.sc +1/4 f.sub.L or 2 f.sub.sc -1/4f.sub.L, where f.sub.sc is the chrominance subcarrier frequency; both these frequencies are of the form (m.+-.1/4)f.sub.L since for N.T.S.C. signals, 2f.sub.sc is an odd integral multiple of f.sub.L. Alternatively, the video signal can be sampled at a frequency which remains constant at precisely 2f.sub.sc during any one line period accompanied by a phase shift of 180.degree. at the start of every alternate time sequential line period. This is described by Rossi in a second paper entitled "Sub-Nyquist Sampled PCM NTSC Color TV Signal Derived from Four Times the Color Subcarrier Sampled Signal" read at the International Broadcasting Convention 1978, and published as IEE Conference Publication No.166 at pages 218 to 221. This latter sampling technique, involving a 180.degree. phase shift, has the advantage that the required samples can be extracted at precisely 4f.sub.sc. This sampling frequency has been recommended as a standard.
The main impairments introduced by the N.T.S.C. sub-Nyquist sampling technique described above have proved to be:
(a) reduction of high frequency diagonal luminance resolution, PA1 (b) reduction of vertical chrominance resolution, and PA1 (c) introduction of alias components into the output signal on diagonal high frequency luminance detail or non-vertical chrominance detail.

Digital processing of N.T.S.C. color television signals


A device, assembly and method for clamping single fibers that utilizes snubbing surfaces simultaneously with magnetic gripping action are described. The device can be fabricated at miniature sizes with very low mass and volume, which are desirable requirements for testing of small fibers in highly sensitive force-transducing load frames. Advantageously, the combined use of snubbing surfaces and magnetic gripping greatly reduces the probability of slippage or fiber failure at the grip during testing.

The ability to test the tensile strength and other mechanical properties of single fibers is of great importance for researchers, engineers, and manufacturers. Single fiber testing can be used to isolate trends and modes of failure for materials, such as for fundamental materials investigations or product-line quality control testing. During development of new fiber materials, the new fibers are often available in very small quantities due to complex processing or exotic materials. In these cases, multi-filament yarn-level testing is not practical. Instead, it is desired to generate mechanical properties of individual filaments.
Developments in capacitive load cells, electromagnetic load cells, and stepper motor technology have led to the commercialization of compact load frames with extremely sensitive force (for example, nanoNewton (nN) sensitivity) and displacement (for example, nanometer (nm) sensitivity) measurement capabilities. These miniature load frames are ideally suited for testing single fibers.
Standard testing procedures for single fibers[1] call for directly gripping single fibers in clamping action grips, or gluing the fibers onto cardboard tabs that are then gripped in clamping action grips. The first technique, direct clamping, concentrates stresses at the grip point and often leads to failure at the fiber grips[2]. Grip failure is undesirable during fiber characterization, and these results are generally not accurate, and, thus, are not reportable. The second technique, bonding fibers onto cardboard tabs, relies on strong bonding between the fiber and a dollop of adhesive. For fibers that are difficult to bond to, such as aramid, polyethylene, or ultrahigh molecular weight polyethylene, it is common to observe fiber slippage from the adhesive. These results are also not accurate and, thus, are not reportable, and generally prevent loading the fiber to failure. In addition, the time and complication associated with utilizing curable adhesives adds considerable inconvenience, especially considering that many test repetitions are required to establish statistically significant data. Accordingly, there is a need for a method, a device and/or an assembly for clamping or otherwise securing a fiber in a tensile testing device.
For testing yarns, it is common to use capstan grips (also called roller grips) or contour/horn grips (also called half-capstan grips)[2, 3]. In these designs, from the primary loading gage section of the yarn the yarn is passed over a series of "snubbing" surfaces which gradually reduce the tensile load on the yarn due to frictional interactions of the yarn with the snubbing surfaces. The snubbing surfaces are curved gently to induce normal forces on the yarn without creating stress concentrations that can fail the yarn. After passing over these snubbing surfaces, the yarn is gripped mechanically, typically using mechanical or pneumatic clamping action. Because the tensile loading on the yarn has been gradually reduced, the total stress on the yarn at the grip point is significantly less likely to lead to failure at the grip.
The present invention improves upon previous single fiber techniques by providing a single fiber clamping device that can reliably grip single fibers and decrease slippage and/or failure at the grips. In addition, no adhesive is required, so that gripping is fast and uncomplicated. Furthermore, the device uses magnetic clamping action to grip the fibers, so that the total mass and volume of the clamping device are minimized. Maintaining low clamping device mass is desirable for operation in sensitive load frames, since the total load limits (including clamp weight) are typically very low for these miniature load frames (for example, 1 N maximum force capacity). For these applications, traditional clamping approaches such as mechanical action or pneumatics are undesirable because they are either impractical or cumbersome to implement.

Fiber snubbing clamp using magnetic gripping action

The United States of America as represented by the Secretary of the Army


Techniques for use in a wireless device which is configured to operate as a group owner (GO) in a peer-to-peer (P2P) network are described. The group owner sends a first multicast message to one or more first P2P devices in the P2P network. The first multicast message includes first notice of absence (NoA) data. The group owner also sends a second multicast message to one or more second P2P devices in the P2P network. The second multicast message includes second NoA data. Partitioning in the P2P network in this fashion may be set based on the different types of communications established with the P2P devices (e.g. different traffic classes or Quality of Service (QoS) types).

1. Field of the Technology
The present disclosure relates generally to communication devices configured for wireless communications, such as IEEE 802.11 based communications, including techniques for use in communicating in a peer-to-peer (P2P) network.
2. Description of the Related Art
A wireless communication device, such as a portable wireless telephony device or smartphone, may be configured to communicate in wireless communication networks. For example, such a device may communicate via access points (APs) of wireless local area networks (WLANs) in accordance with IEEE 802.11 standards or the like. Such devices may also communicate using peer-to-peer communication techniques, for example, in accordance with the Wi-Fi Peer-To-Peer (P2P) Technical specification, and/or be certified as a "Wi-Fi Direct" device.
There is a need for efficiently facilitating communications in these and similar environments.

Methods and apparatus for use in communicating in a peer-to-peer (P2P) network


An electronic camera for capturing and storing images includes an image capture section and an image processing section. The image capture section includes an image sensor for capturing an image and producing pixel data representative of the captured image, an analog-to-digital (A/D) converter for digitizing the pixel data, and a horizontal shift register responsive to applied vertical clock signals for receiving lines of the pixel data from the image sensor and responsive to applied horizontal clock signals for sequentially transferring the lines of pixel data to the A/D converter, the time between the application of horizontal and vertical clock signals providing for a vertical transfer interval wherein pixel data is prevented from being output from the horizontal shift register. The image processing section includes a first-in-first-out (FIFO) memory coupled to the A/D converter for temporarily storing the digitized pixel data, a digital signal processor coupled to the FIFO memory for processing the digitized pixel data, and a storage device coupled to the digital signal processor for storing the processed digitized pixel data. The electronic camera further includes a clock generator for producing the vertical and horizontal clock signals and a FIFO write signal for causing the digitized pixel data from the A/D converter to be transferred to storage locations in the FIFO memory at a first frequency, and a master pixel clock signal. The camera further includes circuitry for producing a FIFO read signal in response to the master pixel clock signal for transferring the digitized pixel data from the FIFO memory to the digital signal processor at a second frequency for processing the digitized pixel data, and after processing, for transferring the processed pixel data to the storage device. The second frequency is selected to be lower than the first frequency.

The present invention relates generally to the field of electronic imaging, and in particular, to an electronic camera having dual clocked line memory.
Many video cameras provide real-time digital processing of images from charge-coupled device (CCD) sensors. The signal processing circuits operate at the same clock frequencies as the sensor and are, therefore, unused during the sensor vertical transfer intervals. In a digital still camera, it is desirable to provide as high a frame rate as possible by reading out the image sensor data as quickly as possible, while still minimizing the clock frequency of the real-time digital processing circuitry, to minimize the cost and power consumption.
Commonly-assigned U.S. Pat. No. 5,016,107, entitled xe2x80x9cElectronic still camera utilizing image compression and digital storage,xe2x80x9d teaches an electronic camera that includes multiple image buffers to allow non-real time processing of the images. By storing the images in frame memories, it is possible to process previously captured images during the vertical transfer intervals associated with the readout of newly captured images. However, this design requires multiple, expensive frame memories and does not allow real-time processing of an image during the vertical transfer interval of that same image.
Accordingly, it is an object of the present invention to provide a digital image camera with increased throughput from the image sensor to image processing to final storage.
This object is achieved by an electronic camera for capturing and storing images, comprising:
(a) an image capture section including:
(i) an image sensor for capturing an image and producing pixel data representative of the captured image;
(ii) an analog-to-digital (A/D) converter for digitizing the pixel data; and
(iii) a horizontal shift register responsive to applied vertical clock signals for receiving lines of the pixel data from the image sensor and responsive to applied horizontal clock signals for sequentially transferring the lines of pixel data to the A/D converter, the time between the application of horizontal and vertical clock signals providing a vertical transfer interval wherein pixel data is prevented from being output from the horizontal shift register; and
(b) an image processing section including:
(i) a first-in-first-out (FIFO) memory coupled to the A/D converter for temporarily storing the digitized pixel data;
(ii) a digital signal processor coupled to the FIFO memory for processing the digitized pixel data; and
(iii) storage means coupled to the digital signal processor for storing the processed digitized pixel data;
(c) clock generator means for producing the vertical and horizontal clock signals and a FIFO write signal for causing the digitized pixel data from the A/D converter to be transferred to storage locations in the FIFO memory at a first frequency, and a master pixel clock signal;
(d) means responsive to the master pixel clock signal for producing a FIFO read signal for transferring the digitized pixel data from the FIFO memory to the digital signal processor at a second frequency for processing the digitized pixel data, and after processing, for transferring the processed pixel data to the storage means; and
(e) wherein the second frequency is selected to be lower than the first frequency.
An advantage of the present invention is to provide an effective way for an electronic camera to increase the throughput by changing the timing of various operating clocks. More particularly, during the time of vertical transfer, pixel data are transferred from the FIFO memory to the digital signal processor. Preferably, all of the pixel data in FIFO memory are transferred during this vertical transfer interval.
Another advantage of the present invention is that the digital signal processor can run slower, and therefore, can consume less power.

Electronic camera having dual clocked line memory


A lateral DMOS FET device which has a small on resistance. The device includes a cell structure formed by a plurality of unit cells, each unit cell including: a source region of first conduction type formed on one side of a substrate of first conduction type; a channel region of second conduction type formed around the source region; and a plurality of drain contact regions of first conduction type located around the channel region; and a source electrode, a gate electrode, and a drain electrode, all of which are formed on the same one side of the substrate. Alternatively, each unit cell may includes: a drain contact region of first conduction type formed on one side of a substrate of first conduction type; a channel region of second conduction type formed around the drain contact region; and a plurality of source regions of first conduction type located around the channel region.

1. Field of the Invention
The present invention relates to a type of a MOSFET device called lateral DMOS FET device.
2. Description of the Background Art
There are two types of a conventional power DMOSFET device, including a vertical DMOSFET (VDMOS) which has a drain electrode on a back side of a substrate, and a lateral DMOSFET (LDMOS) which has a drain electrode formed on a top side of a substrate.
Now, an example of a conventional n-channel type VDMOS shown in FIG. 1 will be described.
In this n-channel type VDMOS, an n.sup.+ -type diffusion layer 4 is formed inside a p-type diffusion layer 3, which is formed inside an n-type epitaxial layer 2 formed on an n.sup.+ -type silicon substrate 12. Also, on a top side of the n-type epitaxial layer 2, a gate electrode 7 is formed on a gate insulation film 6 formed over the p-type diffusion layer 3 functioning as a channel region and the n.sup.+ -type diffusion layer 4 functioning as a source region. The gate electrode 7 is covered by an interlayer insulation film 8, over which a source electrode 16 is formed. In addition, on a back side of the n.sup.+ -type silicon substrate 12 which functions as a drain region, there is formed a drain electrode 13.
In such a VDMOS, the source electrode 16 and the drain electrode 13, which are main passages for the current, are separately provided on the top and back sides of the substrate 12, so that there is no need to collect the current planewise. As a result, the resistance and the area loss due to these components are reduced such that there has been an advantage that the on resistance can be lowered considerably.
However, such a VDMOS has been associated with the following problems.
First, because the drain region is formed by the n.sup.+ -type silicon substrate 12, it has been difficult to form a plurality of VDMOSs on a single substrate, and operating each of them independently, or to form a VDMOS along with other devices such as a CMOS or a bipolar IC.
Secondly, the on resistance is parasitically introduced into the substrate resistance in such a VDMOS.
It has recently become popular in the VDMOS to reduce the on resistance by using finer p-type diffusion layer 3 and n.sup.+ -type diffusion layer 4 manufactured by the improved fine manufacturing technique. There is a device of less than 100 V voltage capacity, which has the on resistance of less than 1 m.OMEGA..multidot.cm.sup.2. Such a device is disclosed by Krishina Shenai et al. in "Blanket LPCVD tungusten Silicide technology for Smart Power Applications", IEEE EDL Vol. 10, No. 5, June 1989.
However, when the finer manufacturing is used, although the channel resistance can be reduced, the resistance of the substrate which makes up the majority of the chip thickness becomes unignorable. Namely, the on resistance R.sub.on can be expressed in terms of the channel resistance R.sub.ch, accumulation resistance R.sub.ac, epitaxial layer spreading resistance R.sub.epi, and substrate resistance R.sub.sub as: EQU R.sub.on =R.sub.ch +R.sub.ac +R.sub.epi +R.sub.sub ( 1)
This implies that the substrate resistance R.sub.sub becomes 30-40% of the entire on resistance R.sub.on for a cell size of 10.times.10 .mu.m, using a gate oxide film thickness=500 .ANG., a gate effective voltage=15 V, an epitaxial layer specific resistance=0.4 .OMEGA..multidot.cm, an epitaxial layer thickness=6.5 .mu.m, a substrate specific resistance=0.04 .OMEGA..multidot.cm, and a substrate thickness=380 .mu.m.
The substrate resistance can be reduced by increasing the impurity density or by thinning the substrate thickness, but the former has a problem that the deterioration of the crystallization property of the epitaxial layer can also be caused, while the latter has a problem of a wafer cracking due to the reduced mechanical strength. Thus, there is a limit to an extent that the on resistance can be reduced.
On the other hand, an example of one type of a conventional n-channel type LDMOS is shown in FIG. 2, which will now be described.
In this n-channel type LDMOS, an n.sup.+ -type diffusion layer 4 is formed inside a p-type diffusion layer 3, which is formed inside an n-type epitaxial layer 2 formed on a p-type silicon substrate 1. Also, on a top side of the n-type epitaxial layer 2, a gate electrode 7 is formed on a gate insulation film 6 formed over the p-type diffusion layer 3 functioning as a channel region and the n.sup.+ -type diffusion layer 4 functioning as a source region. The gate electrode 7 is covered by an interlayer insulation film 8, over which a source electrode 16 is formed. In addition, there is provided an n-type diffusion layer 15 which is making a contact with an n.sup.+ -type buried layer 14 formed between the p-type silicon substrate 1 and the n-type epitaxial layer 2, and an n.sup.+ -type diffusion layer 5 is formed inside the n-type diffusion layer 15, such that a drain electrode 17 can be formed over the n.sup.+ -type diffusion layer 5 on a top side of the p-type silicon substrate 1.
In such an LDMOS, because it is entirely formed on the grounded p-type silicon layer 1, there has been advantages that such an LDMOS can be formed along with the other electrically isolated devices or LDMOSs, and the effect of the substrate resistance on the on resistance is very small.
However, there has also been a problem that the device area have to be enlarged in order to incorporate the n-type diffusion layer 15 and the drain electrode 17. The area required for this reason needs to be as large as that covered by the source electrode, in order to have the drain current flow.
In this type of LDMOS, the source electrode 16 and the drain electrode 17 are arranged as shown in FIG. 3. As shown, the source electrode 16 and the drain electrode 17 are shaped in comblike shapes and are arranged to be gearing with each other, in contrast to the case of VDMOS in which these components are formed over the entire front and back sides. These source and drain electrodes 16 and 17 are also shaped such that their width becomes wider toward positions of bonding pads 18 and 19. The width in a vicinity of the bonding pads 18 and 19 have to be greater for the device of larger current capacity, and therefore the dead space in the device increases as its current capacity increases.
Now, the reduction of the on resistance by using the improved fine manufacturing technique, popularly exercised for a VDMOS as already mentioned above, is not effective in reducing the dead space in the LDMOS, so that the extent by which the on resistance can be reduced has been rather limited in the LDMOS.
Also, in this type of LDMOS, there has been a problem that although the substrate resistance is very small, the parasitic drain resistance due to the resistance of n-type diffused layer and n.sup.+ -type buried layer is large. This parasitic drain resistance can be reduced effectively by enlarging the total area of the n-type diffusion layer 15 so as to reduce the distance that the current have to travel through the n.sup.+ -type buried layer 14. However, this in turn increases the dead space in the LDMOS.
Thus, the on resistance in this type of the LDMOS has usually been over twice as large as the VDMOS of the same device area. For this reason, the use of this type of the LDMOS has been limited to cases involving a small or medium amount of current only. For a case involving a large amount of current such as that over 10A, the device area of the LDMOS becomes practically too large.
There is also another type of an LDMOS in which the current flows along the substrate surface, which is shown in FIG. 4 and will now be described.
In this LDMOS of FIG. 4, a p-type diffusion layer 3 functioning as a channel region and an n.sup.+ -type diffusion layer 5 functioning as a drain contact region are formed inside an n-type epitaxial layer 2 formed on a p-type silicon substrate 1. Inside the p-type diffusion layer 3, n.sup.+ -type diffusion layer 4 functioning as a source region is formed. Also, on a top side of the p-type silicon substrate 1, a gate electrode 7 is formed on a gate insulation film 6 formed over the p-type diffusion layer 3 and the n.sup.+ -type diffusion layer 4. The gate electrode 7 is covered by an interlayer insulation film 8, over which a source electrode 16 is formed. In addition, over the n.sup.+ -type diffusion layer 5, a drain electrode 17 is formed on a top side of the p-type silicon substrate 1.
In such an LDMOS, just as in the LDMOS of FIG. 2 described above, because it is entirely formed on the grounded p-type silicon layer 1, there is an advantage that such an LDMOS can be formed along with the other electrically isolated devices or LDMOSs.
Furthermore, in this type of the LDMOS, the parasitic drain resistance can be reduced as there is no n.sup.+ -type buried layer 14 through which the current have to pass.
However, this type of the LDMOS is also associated with the problem of the enlargement of the device size due to the inclusion of the n.sup.+ -type diffusion layer 5 and the drain electrode 17, which gives rise to the problem of the larger dead space for the larger current capacity, as in the LDMOS of FIG. 2.
In addition, because the source electrode 16 and the drain electrode 17 are in comblike shapes and also because the source region 4 and the drain connector region 5 have to be arranged adjacent to each other, the source region 4 have to be in stripe-shape which runs parallel to the comblike shape of the source electrode 16, such that the cell arrangement commonly utilized in the VDMOS has not been applicable to the LDMOS. The stripe arrangement is known to have the smaller channel width per unit area, so that there is a limit to which the on resistance can be reduced in the stripe arrangement, compared with the cell arrangement.
Thus, the on resistance in this type of the LDMOS has also usually been over twice as large as the VDMOS of the same device area.
Therefore, two types of the conventional LDMOS described so far are known to be advantageous in that they are suitable for being integrated with the other devices or made into multiple output configuration, as it has the drain electrode on the top side of the substrate, but they also have the problem of having the higher on resistance compared with the VDMOS which has the drain electrode on the back side of the substrate, such that they are less desirable in terms of costs, as well as in terms of the limit on the current capacity.
Also, in the LDMOS, since the current flows mostly on the top side of substrate, the effect of the substrate resistance becomes small. However, the device area have to be enlarged in order to incorporate the n-type diffusion layer 15 and the drain electrode 17, and the resulting increase of the wirings reduces the cell density.
As an effective cell pattern for LDMOS which can resolve the problems of the conventional LDMOS described above, a mesh-gate structure shown in FIG. 5 has been known conventionally.
In this mesh-gate structure, source openings 105 and drain openings 106 are formed by square cuttings on the gate electrode 107, and are arranged one next to another. The drain and source electrodes 113A and 116A are arranged over the source and drain openings 105 and 106 in a stripe pattern running obliquely.
On the source openings 105, the p-type channel region 103 and the n-type source region 104 are formed by using the diffusion self-align technique. On the drain openings 106, high density n-type impurities are doped in order to obtain the low Ohmic contact with the electrode.
In this mesh-gate structure, the on resistance can be reduced efficiently as the source and drain are separated in each unit cell. However, since the source openings 105 and the drain openings 106 have the same area, there is a problem in reducing the on resistance further.
Namely, the on resistance R.sub.on in this case can be expressed in terms of the channel resistance R.sub.ch, accumulation resistance R.sub.ac, epitaxial layer spreading resistance R.sub.epi, and substrate resistance R.sub.sub as: ##EQU1## where the first term on the right hand side of the equation (2) R.sub.ch, largely depends on the size of the source openings 105, while the second term on the right hand side largely depends on the size of the drain openings 106.
However, since the source openings 105 and the drain openings 106 have the same area, these first and second terms on the right hand side are automatically determined when the resistance of each part is determined from other conditions on the device such as the voltage capacity.
In particular, when the values of the first term and the second term are largely different, the larger one makes a dominant contribution to the on resistance, and sets the limit to an extent by which the on resistance can be reduced.

Lateral DMOS FET device with reduced on resistance


A glyceride product is prepared by interesterifying a glyceride mixture in the presence of a lipase as a catalyst with a dihydric alcohol, a trihydric alcohol, or mixture thereof, said glyceride mixture being composed of at least two different glycerides or at least one glyceride and at least one fatty acid.

1. Field of the Invention
The present invention relates to a method of producing an improved glyceride product by interesterification with lipase.
2. Description of the Prior Art
Interesterification and hydrogenation are techniques which have been useful in the preparation of glyceride products for use in the manufacture of butter and margarine. In the conventional interesterification reaction, interesterification is conducted in the presence of a catalyst such as sodium, sodium methylate, or the like. However, the conventional reaction is not selective with respect to esterification of a fatty acid substrate at a reactive position with glycerine. On the other hand, an interesterification process conducted in the presence of lipase as a catalyst (Japanese Published Unexamined Patent Application No. 104506/1977) is know, however, this process requires the presence of water to activate the lipase. The presence of water causes hydrolysis of interesterified glycerides with resultant decreases in yield of the glyceride product. Therefore, a need continues to exist for a method of improving the yield of glyceride products by an interesterification reaction.

Method of producing improved glyceride by lipase


In a clamping lock for antiskid chains with a housing supporting an actuating lever which has a catch position in which a clamping rope which can be pulled through a housing opening into the housing for purposes of clamping can be locked against its clamping direction and has a release position in which the clamping rope can be released from this locking, the clamping rope is connected inside the housing to a winding device which is pretensioned in the wind-up direction.

a) Field of the Invention
Clamping lock for an antiskid chain with a housing to which is fitted an actuating lever having a catch position in which a clamping rope which can be pulled through a housing opening into the housing for purposes of clamping can be locked against its clamping direction and having a second position in which it can be released from this locking.
b) Description of the Related Art
Such clamping locks are used in antiskid chains in order to prevent the clamping member which can be formed of a length of chain or, e.g., a flexible wire, from running back in an undesirable manner opposite to the clamping direction when clamping the chain netting after mounting and, accordingly, to ensure that the displacements of the clamping rope caused in the pulling or tightening direction cannot be canceled, i.e., to ensure that the clamping rope is held in the clamping position that has been achieved.
In known clamping locks, the clamping rope is guided through the clamping lock and along a deflecting element that is arranged inside the housing of the clamping lock, whereupon it exits again from the housing of the clamping lock and can be grasped by the user in order to exert the desired pulling action. When the chain netting is clamped, the portion of the clamping rope hanging out of the housing on the pull-out side is then suitably hooked into the outer side chain (usually with the intermediary of an elastically stretchable link at the end of the clamping rope) or elsewhere in the chain netting on the side of the chain external to the vehicle.
A clamping lock of this type is known from EP-B-0 385 057. In this case, an actuating lever is provided at the housing and is pretensioned in a catch position by means of a spring and has a catch nose by which it engages in the catch position in a link of the clamping member formed as a length of chain, wherein the latter is locked in position against the clamping direction and is released in a positive-locking manner when the clamping member is moved in the clamping direction due to the special configuration of the catch nose. This enables a movement of the clamping member through the clamping lock in the pulling direction, while an automatic locking is effected opposite to the pulling direction. However, the user can cancel the locking when desired by pressing on the actuating lever and can accordingly make it possible for the clamping member to run freely through the clamping lock, e.g., in order to cancel the clamping of the chain netting when removing the chain.
In another known clamping lock (DE-A-40 39 665) which is likewise constructed in the manner mentioned above, the clamping rope can be introduced into the housing laterally via an insertion slot extending along the entire height of the housing of the clamping lock, which facilitates insertion of the clamping rope into the housing, while the clamping of the chain netting is carried out in the same manner as that of the known clamping lock described above.
In clamping locks of this type, the clamping force must be applied manually to the clamping member by the user who must pull with suitable force in the clamping direction on the end of the clamping rope running out of the housing until achieving the desired clamped position of the chain netting on the wheel. The end of the clamping rope hanging out on the pulling side must then be fastened in a suitable manner on the outside of the chain netting, likewise accompanied by tension, so that a clamped fit is finally achieved overall. In this way, the user can initially achieve a tight fit of the chain while clamping it to the wheel, but when the vehicle is moved, the occurring forces cause the chain to settle on the circumference of the wheel so that the applied tension is reduced and it becomes necessary to tighten the clamping rope again after traveling a certain distance. Only in this way can the chain be prevented from assuming a loose fit on the wheel with all of the consequent disadvantages (such as inadequate effect, loud chain noise during driving, risk of damage to the chain or to other parts of the vehicle by loose chain components) in spite of an initial firm clamping due to the settling movements of the chain itself.


A method and apparatus for inspecting a repeating pattern on an object using an optical inspection system to detect variations in the pattern. The object is illuminated with substantially monochromatic light. A diffracted beam is formed. The diffracted beam has a plurality of polarization components. At least one of the polarization components of the diffracted beam is blocked. Variations in the pattern are detected as light intensity variations in the polarization components that are not blocked.

1. Field of the Invention
The present invention relates to optical inspection systems, and in particular, to optical systems for inspecting repeating patterns.
2. The Related Art
In the manufacture of integrated circuits (ICs), it is well known to apply a pattern to a substrate by masking a portion of the substrate corresponding to a pattern, and by selectively depositing or removing material on the substrate to form the lines and devices of the IC. Variations in the pattern, including both pattern width and pattern depth, may occur for a variety of reasons. For example, they may occur due to variations in the application of masking material, exposure and development. To achieve the desired accuracy in the ICs, the patterns are often checked during the processing (for end point detection), as well as after completion of circuit processing.
The determination of the shape, depth and width of sub-micron structures on semiconductor wafers can be a difficult task. With sub-micron sized patterns, it has become a common practice to destructively test samples using a scanning electron microscope. This is a time consuming process. It is often desirable to test whether a structure has been formed properly by comparison to a known structure or measurement signature. Such a comparison is useful as an end point detection mechanism, or as an indication of the success of the formation process.
U.S. Pat. No. 4,303,341 to Kleinknecht et al. discusses an inspection method in which a diffraction grating is applied to the substrate being tested. The diffraction grating includes a pattern of evenly spaced lines having a pitch of about 20 micrometers and a line width of 5 micrometers. The substrate is illuminated by a beam of light to form a reflected beam and to form first and second order diffracted beams, having respective intensities I.sub.1 and I.sub.2. The ratio of I.sub.2 /I.sub.1 is calculated. The width of the lines is then calculated from the ratio of I.sub.2 /I.sub.1.
Another method for inspecting repeating patterns has been proposed in Giapis, K. et al., "Use of Light Scattering in Characterizing Reactively Ion Etched Profiles," J. Vac. Sci. Technol. A, Vol. 9, No.3, May 1991, involves the measurement of scattered light intensity. A repeating pattern is illuminated with a laser beam to produce a plurality of diffraction orders. The repeating pattern is spaced widely, with a pitch of approximately 32 micrometers. The large pitch ensures that there are many diffraction orders available for evaluation. The intensity of each diffraction order is then measured. Deviations in the intensity profile are an indication of changes in the repetitive structure.
A disadvantage of the method described above is that, in order to achieve closely spaced diffraction orders, the repeating structures are placed relatively far apart, i.e., 32 micrometers. The patterns on the integrated circuits that are being inspected, however, are closely spaced. This means that the repeating circuit patterns themselves produce very few diffraction orders (when visible wavelengths are used). To overcome this limitation, the inspection method described by Giapis et al. has been performed on test patterns in the form of diffraction gratings on the substrate, instead of using the actual circuit patterns themselves.
Ellipsometry is a different technique that has been used for nondestructively measuring the thicknesses of films, given the complex index of refraction for the film and bare substrate. In ellipsometry, light of a known polarization and incident angle is reflected from the substrate, and relative shifts in the polarization state are measured. In a typical configuration the incident beam is a monochromatic beam that is passed through an adjustable polarizer (e.g., a polarizer and a compensator). The incident beam has both P and S polarizations (parallel to and perpendicular to the plane of incidence, respectively). The reflected beam is passed through an analyzing polarizer, and on to a detector. The adjustable polarizer is adjusted until the light reaching the detector is nulled. The setting of the adjustable polarizer that nulls the detected light determines the field reflection coefficients.
Ellipsometry is useful for analyzing the average film thickness value over an area. Scattering within the reflected beam causes the light from the repeated pattern and from the variations to be intermingled, which achieves averaging. This is a disadvantage, however, if the purpose of the measurement is to detect the variations, as opposed to detecting the average. For spatial resolution over a broad area using ellipsometry, one solution has been to focus the beam on a small portion of the surface and to scan the beam over the surface, one portion at a time. For a large surface this process may involve the scanning of thousands of portions, and may take hours to complete.
Cohn, R. et al., "Dynamic Imaging Microellipsometry; Theory, System Design and Feasibility Demonstration", in Applied Optics/Vol. 27, No. 22, November, 1988 and Cohn, R. and Wagner, J., "Mapping of Surface Film Parameters with Dynamic Imaging Microellipsometry", Quantitative Nondestructive Evaluation, Vol. 8B, discuss imaging ellipsometry devices. In each case, the reflected beam has an angle with respect to the surface normal, and part of the image is out of focus.

Method and apparatus for inspecting patterned thin films using diffracted beam ellipsometry

International Business Machines Corporation


A process of making a mixed salt of a polymer containing an anhydride, acid or ester side groups therein which comprises:. (a) forming a reaction mixture of the polymer, mixed salt compounds and water, in a predetermined proportion, as a paste or slurry, PA1 (b) reacting and extruding the paste or slurry at a predetermined temperature to form the mixed salt of the polymer, and PA1 (c) drying the resultant reaction product.

1. Field of the Invention
This invention relates to reactive extrusion, and, more particularly, to a continuous process for manufacturing mixed salts of polymers containing an anhydride, acid or ester side groups under reactive extrusion conditions.
2. Description of the Prior Art
Mixed salts of copolymers of maleic anhydride and methyl vinyl ether, for denture adhesive applications generally are made by batch process, a neutralization reaction, in a dilute aqueous solution of the copolymer and suitable mixed salt compounds. However, it is desired to provide an improved process for making such products, preferably in a continuous and rapid manner, and under high solids conditions.

Reactive extrusion process for making mixed salts of polymers containing an anhydride, acid or ester side groups


An illumination optical system comprises a light source lamp (1), a light mixing element (3) for mixing light emitted from the light source lamp (1), a DMD element (5) having a plurality of pixels, a transmission optical system (4) for bringing a light-exit surface (3a) of the light mixing element (3) into optical conjugation with a to-be-illuminated surface (5S) of the DMD element (5), and a field lens (6) located in front of the DMD element (5). The focal length of the field lens (6) can be changed so that an illuminance distribution that varies according to the application of the illumination optical system can be achieved on the to-be-illuminated surface (5S).

1. Field of the Invention
The present invention relates to an illumination optical system using a reflecting light valve such as a digital micromirror device (referred to as xe2x80x9cDMDxe2x80x9d hereinafter) or a reflecting liquid crystal display. It also relates to a projection display (e.g., projector) including the illumination optical system.
2. Description of the Background Art
FIG. 14 is a schematic diagram of an illumination optical system applied to a conventional projection display disclosed in Japanese Patent Application Laid-open No. 2000-241755. In FIG. 14, reference numeral 31 designates a light source and reference numeral 32 designates a parabolic mirror that reflects light from the light source 31 and makes the reflected light generally parallel to an optical axis of illumination. Reference numeral 33 designates a first lens array, reference numeral 34 designates a convex lens constituting the first lens array 33, reference numeral 35 designates a second lens array, and reference numerals 36 and 37 designate convex lenses constituting the second lens array 35. Further, reference numeral 38 designates a collective lens and reference numeral 39 designates a to-be-illuminated surface.
Light emitted from the light source 31 and then reflected by the parabolic mirror 32 is generally made parallel; however, in the open end of the parabolic mirror 32, the light intensity distribution in the periphery is higher than that in the center because of the influences of optical properties of the light source 31 such as light emission and light distribution. The illumination optical system of FIG. 14 has the functions of reducing such a deviation of the illumination light distribution and illuminating the central portion of the to-be-illuminated surface more brightly than the peripheral portion. Now, the operation of the illumination optical system in FIG. 14 will be briefly described.
The first lens array 33 is formed of an array of a plurality of convex lenses 34 having the same focal length. The second lens array 35, on the other hand, is formed of an array of alternate convex lenses 36 and 37 having two different focal lengths. The focal length of the convex lenses 36 is determined so as to adjust, in combination with the condenser lens 38, the focus of their corresponding convex lenses 34 in the first lens array 33 on the to-be-illuminated surface 39. From this, light passing through half of the convex lenses 34 in the first lens array 33 is superimposed on the to-be-illuminated surface 39, and even if the light intensity distribution in the open end of the parabolic mirror 32 is not uniform, the to-be-illuminated surface 39 can be provided with a uniform illuminance distribution.
The focal length of the convex lenses 37, on the other hand, is determined to be greater than that of the convex lenses 36; therefore, even in combination with the condenser lens 38, the focus of their corresponding convex lenses 34 in the first lens array 33 cannot be adjusted on the to-be-illuminated surface 39. That is, light passing through the convex lenses 37 has a convexly curved illuminance distribution on the to-be-illuminated surface 39, with the central portion being higher in illuminance than the peripheral portion.
As above described, the illuminance distribution on the to-be-illuminated surface 39 is formed by a combination of (i) the uniform illuminance distribution of the light passing through the convex lenses 36 and (ii) the convexly curved illuminance distribution of the light passing through the convex lenses 37. That is, the illuminance distribution on the to-be-illuminated surface 39 gently changes within an effective illuminated area on the to-be-illuminated surface 39, with the central portion being higher in illuminance than the peripheral portion. This achieves a projection display capable of making improvement on uniform illumination that is not suitable for TV image display, for example.
In the above conventional projection display illustrated in FIG. 14, however, the light passing through the convex lenses 37, which account for one half of the total lenses in the second lens array 35, is not focused on the to-be-illuminated surface 39. Accordingly, a light source image to be formed on the pupil of a projection lens (not shown) is out of focus as well. Considering efficiency of light utilization, the light source image on the pupil should be in sharp focus. From this, the conventional projection display in FIG. 14 has a problem that the positive provision of the convex lenses 37 causes defocusing as above described, thereby resulting in unavoidable energy loss.
A first aspect of the present invention is directed to an illumination optical system comprising: a light source; a light mixing element mixing light emitted from the light source; a reflecting light valve having a plurality of pixels; a transmission optical system located between the light mixing element and the reflecting light valve and bringing a light exit surface of the light mixing element into optical conjugation with a to-be-illuminated surface of the reflecting light valve; and a field lens located between the transmission optical system and the reflecting light valve, wherein a focal length of the field lens is determined so that an illuminance distribution which varies according to the application of the illumination optical system can be achieved on the to-be-illuminated surface.
According to a second aspect of the present invention, in the illumination optical system of the first aspect, the focal length of the field lens is determined so that an illumination margin takes on a value in the neighborhood of 1.0, and a diagonal dimension of a to-be-illuminated area on the to-be-illuminated surface is equivalent to the product of a diagonal dimension of the to-be-illuminated surface and the illumination margin.
According to a third aspect of the present invention, in the illumination optical system of the first aspect, the focal length of the field lens is determined by obtaining at least one of a radius of curvature of the field lens and the type of a glass material forming the field lens on the basis of the illuminance distribution which varies according to the application of the illumination optical system.
According to a fourth aspect of the present invention, in the illumination optical system of the first aspect, the light exit surface of the light mixing element and the to-be-illuminated surface of the reflecting light valve are generally similar in shape.
According to a fifth aspect of the present invention, in the illumination optical system of the first aspect, the plurality of pixels in the reflecting light valve each are configured of a micromirror having a variable angle of inclination.
According to a sixth aspect of the present invention, in the illumination optical system of the first aspect, the light mixing element is formed in the shape of a hollow rod, using its inner surface as a reflecting surface.
According to a seventh aspect of the present invention, the illumination optical system of the first aspect further comprises: a rotary color filter located either in front of or behind the light mixing element to pass the light emitted from the light source.
According to an eighth aspect of the present invention, in the illumination optical system of the first aspect, the field lens is a planoconvex lens having a plane surface on the side of the to-be-illuminated surface of the reflecting light valve.
According to a ninth aspect of the present invention, in the illumination optical system of the first aspect, the field lens has at least one aspherical surface.
According to a tenth aspect of the present invention, in the illumination optical system of the first aspect, the field lens is a Fresnel lens.
An eleventh aspect of the present invention is directed to a projection display comprising: the illumination optical system of the first aspect; a screen; and a projection lens system located between the reflecting light valve and the screen.
The first, second, and eleventh aspects of the present invention can achieve the effect of, by simply changing the focal length of the field lens located in front of the reflecting light valve, easily achieving various illuminance distributions depending on applications of the illumination optical system on the reflecting light valve, without reducing the efficiency of light utilization.
The third aspect of the present invention can achieve the effect of, by simply replacing the field lens, achieving different illuminance distributions on the reflecting light valve without giving any change to the optical elements other than the field lens and to the structural members holding the optical elements.
The fourth aspect of the present invention can achieve the effect of allowing easy design of the light mixing element and minimized optical losses.
The fifth aspect of the present invention can achieve the effect of providing a low-cost, light-efficient device.
The sixth aspect of the present invention can achieve the effect of simplifying the ways of cooling and holding the light mixing element.
The seventh aspect of the present invention can achieve the effect of providing a compact, light-efficient device.
The eighth aspect of the present invention can achieve the effect of facilitating the settings of the relative positions of the field lens and the reflecting light valve.
The ninth and tenth aspects of the present invention can achieve the effect of achieving high image performance while correcting high-order off-axis aberration such as distortion, coma, and astigmatism.
The present invention has been made in view of the aforementioned conventional problems and an object thereof is to achieve, on a reflecting light valve, various illuminance distributions depending on applications of the illumination optical system or projection display, while improving the efficiency of light utilization without energy loss. More specifically, the principal object of the present invention is to achieve (i) a uniform illuminance distribution on a to-be-illuminated surface of the reflecting light valve and conversely (ii) a non-uniform illuminance distribution on the to-be-illuminated surface of the reflecting light valve.
These and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.

Illumination optical system with reflecting light valve


An apparatus for turning up and down seats for a telescopic seating system includes as essential components a foot on which a single seat is fixedly mounted, a base frame having a support shaft inserted therethrough in the transverse direction so as to allow the foot to be turned up and down about the support shaft, a center shaft extending through the base frame in parallel with the support shaft and including an extension outside of the housing, a guide arm turnably mounted on the extension of the center shaft, a pair of first coil springs mounted on the support shaft within the interior of the base frame so as to allow the foot to be normally biased in the turning-up direction, a second coil spring mounted on the extension of the center shaft so as to allow the guide arm to be normally turnably biased in the forward direction, and a pair of tongue-shaped projections fixedly mounted on the center shaft within the interior of the base frame, a link plate bridged between a front shaft on the foot and a rear shaft on the tongue-shaped projections. When the telescopic seating system is in use, turning movement of the guide arm induced by forward movement of a movable platform at the lower stage is transmitted to the foot via the center shaft, the tongue-shaped projections and the link plate, whereby the foot is turned up to assume the upright standing attitude.

Field of the Invention
The present invention relates generally to an apparatus for turning up and down a number of seats for a telescopic seating system. More particularly, the present invention relates to an apparatus for turning up spectators' seats to assume the upright standing attitude before using the telescopic seating system and turning down them to assume the horizontally laid attitude after completion of the practical use of the same.

Apparatus for turning up an down seats for telescopic seating system


A binding tool for assisting in the task of folding and pressing bindings and ruffles and to a method of use thereof. The binding tool has a tool body having a top side and a bottom side and a slot disposed through the body for receiving a strip of cloth to be folded. The binding tool is used by placing the body member onto the top of an ironing board whereby the slot extends from the top of the ironing board upwardly through the body member. One end of a strip cloth is folded and then threaded through the slot from the top of the body down so that it extends between the body and the top of the ironing board. A heated iron is placed on a portion of the folded strip of cloth and then the strip of cloth is pulled through the slot whereby it is folded and simultaneously pulled under the iron and between the iron and the ironing board whereby it is pressed. The binding tool body also has a mechanism thereon for adjusting the effective width of the slot to correspond approximately to the width of the cloth in a folded condition thereof. Straps are provided for attaching the binding tool body securely to the top of an ironing board, although other fastening devices can be used instead.

The traditional way of folding and pressing a binding or ruffle is shown in FIG. 10 of the drawings whereby a first portion of a strip of cloth is first folded by hand and then this folded portion is pressed on an ironing board. Then a second portion of the strip of cloth is folded and then pressed just like the first portion until the entire strip of cloth is folded and pressed. This manual folding and pressing process is a difficult, slow and tedious process.
Attempts have been made to pull a funnel-like member over a strip of cloth, to fold the cloth and then to press the strip of cloth. Such attempts and devices do not hold cloth down onto the ironing board so the pressing is not as precise as is desired. Also, to perform this process, a user must buy and use different sizes for different widths of binding cloth. This is a problem also because these devices are available only in standard sizes and it is sometimes desired to fold non-standard sizes.
Accordingly, there is a need in this industry to have methods and devices for solving the aforementioned problems.

Method and apparatus for folding and pressing bindings and ruffles


A wire having a terminal crimped to one end thereof and an electrodeposited metal emanating from either the terminal or the wire electrically bridging the wire and the terminal. A process for making the aforesaid wherein the terminal and the wire comprise dissimilar metals having different oxidation potentials in the presence of an electrolyte and wherein the joint between the terminal and the wire is contacted with an electrolyte to deplate the more anodic metal and deposit it on the more cathodic metal.

It is well known to mechanically crimp terminals onto the end of electrical wires. Crimping provides a permanent electrical and mechanical connection between the wire and the terminal. Such connections are common in single and multi-strand wires. The terminals typically include a nest portion that receives the wire and at least one wing portion which overlies the wire and is crimped thereto along with the body of the terminal defining the nest portion so as to securely hold the wire therebetween.
One of the problems with crimped connections is that, following the crimping step, the wing(s) will frequently spring back somewhat resulting in a somewhat looser grip on the wire than occurs while the wire/terminal are in the jaws of the crimper. Such spring back often leaves small air gaps between the terminal and the wire. The electrical resistance between crimped terminals and their associated wire typically increases with time as the wires and terminals oxidize and contaminants accumulate in the air gaps that are formed between the wire and the terminal. This problem is more acute in multi-strand wires where the crimping operation also tends to separate some of the strands forming small gaps therebetween and providing a higher surface area exposed to such oxidation/contamination then would otherwise occur if the bundle of wires had not been squeezed in the crimper.
One way to eliminate the aforesaid problem and provide a permanent low-resistance connection is to solder the terminal to the wire. The solder forms a stable metallurgical bond to both the terminal and the wire which precludes subsequent oxidation/contamination from occurring in the gaps and forms a conductive metallic bridge between the wires and terminals which provides a long term, low-resistance connection. Unfortunately, crimped and soldered connections are expensive to manufacture, and often difficult to control, process-wise. It would be desirable if an inexpensive technique could be developed to provide a conductive metal bridge between a wire and a terminal crimped thereon which, in turn, produces a long term, low-resistance connection.
It is an object of the present invention to provide an unique low-resistance, crimped-on, wire-terminal connection having a low resistance, metallic bridge between the terminal and the wire, and a simple, inexpensive technique for making such a connection.
This and other objects and advantages of the present invention will become more readily apparent from the detailed description thereof which follows.

Galvanically enhanced crimped connection


A box for connecting a ribbon output conductor of a solar panel with a feed cable has a base mountable on the solar panel and formed with a first hole for the ribbon output conductor and a second hole for the feed cable, a removable cover fittable with the base and forming when fitted with the base a substantially closed compartment, and two holders at the first hole oriented at a predetermined angle to each other and adapted to hold a conductive part of the feed cable in either of two positions offset by the predetermined angle relative to the first hole.

A standard connection box for a solar panel has a cover and a base. The base has a first opening for a ribbon panel-output conductor and a second opening for a feed cable to be coupled to the panel-output conductor. This feed cable has a lead projecting into a compartment formed by the base to which the panel-output conductor is mounted so as to form therewith an electrical connection. Holders secure the feed cable inside the connection box in a stable manner.
Standard prior-art solar panels are known that are equipped with ribbon or strip panel-output conductors to conduct electricity generated by the panel to the feed cables. These panel-output conductors are fitted into the connection boxes and mounted there on leads of the feed cables. The leads can be components of the feed cables themselves, such as, for example, a core conductor, or also contacts provided on the feed cable. The leads are typically held in a stationary fixed fashion in the base.
Depending on the type of solar panel, the panel-output conductors extend through opening in different orientations. This means that the ribbon-type panel-output conductor is oriented horizontally in a first embodiment, while in a second embodiment it is vertical. In other words, the ribbon-type panel-output conductor in the second embodiment is angled 90° offset to the first embodiment. As a result, a supply of different connection boxes must be made that differ specifically in terms of the arrangement of the incoming leads or conductors.


Methods and systems for vehicle sensor compensation are provided. A sensor is configured to at least facilitating obtaining sensor data pertaining to an object in proximity to the vehicle. The sensor data includes a measured azimuth angle value for the object. A processor is coupled to the sensor. The processor is coupled to the sensor, and is configured to at least facilitate estimating a misalignment angle for the sensor using the sensor data and generating a correction factor for the measured azimuth angle value using the misalignment angle.

Many vehicles today have sensors that obtain data pertaining to objects that may be in proximity to vehicles. For example, many vehicles today use radar sensors, cameras, and/or light detection and ranging (LIDAR) devices for obtaining data pertaining to such objects, which may include, for example, other vehicles, other moving objects, and/or fixed objects in proximity to the vehicle. However, in certain cases there can be a misalignment of such sensors, which could affect the data pertaining to the objects.
Accordingly, it is desirable to provide techniques for using data from vehicle sensors, such as radar, camera, and LIDAR sensors of vehicles, for example in the event of misalignment of such sensors. It is also desirable to provide methods, systems, and vehicles utilizing such techniques. Furthermore, other desirable features and characteristics of the present invention will be apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.

This patent is subject to a terminal disclaimer.


A method and apparatus for compensating for media shift due to spiral groove roller tape guide is disclosed. The lateral tape shift is measured. Then the control of the coarse actuator is adjusted for the lateral tape shift so that the movement of the coarse actuator follows the tape shift.

1. Field of the Invention
This invention relates in general to track following servo control for data storage systems, and more particularly to a method and apparatus for compensating for lateral media shift resulting in forward to backward offset in tape guiding.
2. Description of Related Art
Due to the Internet and the globalization of manufacturing and service-oriented industries, businesses are collecting and analyzing data at an ever increasing rate. As organizations' data warehouses grow, the threat of data loss carries a potentially larger fiscal price. For example, the value of data often exceeds the value of the computer system within weeks of installation of the system. Many factors can cause the loss of data including power brownout, power failure, human error, hard disk failure and other natural disasters. In many cases, the lost data, if not properly backed-up, is simply not recoverable. In other cases, data may still be re-assembled or re-captured from other system either electronically or manually, but both certainly involve a lot of cost and time.
As computing environments have evolved toward data-intensive networks of servers with high system administration costs, the techniques for reliable backup have had to change to meet new needs. The art of data backup has evolved significantly in recent years from individual SCSI drives backing up single computers to automated library systems backing up heterogeneous networks of servers.
Data storage on magnetic tape is well known and tape recorders have been used to record data tracks on magnetic tape. Traditionally, data is recorded in a plurality of parallel data tracks on the magnetic tape. The head is then positioned relative to the tape path by moving the read/write head to different track positions as desired while holding the read/write head stationary. In such a system, the tape tracks must both be sufficiently wide and separated to guarantee that the exposure of the data track to the head is accurate at least to the minimum requirements necessary to reliably read and write the data. The read/write head is positioned at a predetermined fixed point, relative to the magnetic tape path and the data track must accommodate variations of recording track location and tape location variances as the tape feeds past the head. Historically, this accommodation has been accomplished insuring that the track width and the data track separation on the magnetic tape are sufficient for the read/write head to remain positioned over the designated track and at the same time not read magnetically recorded signals from an adjacent track. This arrangement of track width and track separation will accommodate any deviation of the track location from the design norm either due to being recorded on a first recorder and played or rerecorded on a second recorder or due to the wander of the tape as it is spooled past the read/write head from one spool to the other spool of a cartridge.
The definition of the magnetic read/write head and the track width and separations effectively limits the number of data tracks that may be recorded on any given width of tape. Reliance solely on the track width and track separations to insure reliable read/write operations results in a significant waste of magnetic tape surface and thus limits the data density on the tape. Data may be recorded in tracks that are much narrower and still be reliable from a read/write standpoint, but the read/write head must be and remain perfectly aligned with the data track. However, as the track width and the read/write head width narrow in an effort to increase the data capacity of a given tape area, any misalignment of the head with the track may lead to read/write repeatability failures and lost data. Thus, the resolution of the head placement mechanism and the precision of the placement of the tape relative to the read/write head become limiting factors affecting the recording density of data on the magnetic tape surface in tape drives having static read/write heads.
In high track density tape storage devices, a compound actuator is used for track following system. The compound actuator includes a coarse actuator which usually is a stepper motor and a fine actuator which has a linear high bandwidth, limited range of travel. The compound actuator thus has the advantage of high bandwidth and large working dynamic range. Another important aspect of the tape drive is the tape guide which guides the tape over the read/write/servo head in a stable manner to allow reliable track following.
Typically, tape drive systems provide tape guides for controlling the lateral movement of the tape as the tape is moved along a tape path in a longitudinal direction across a tape head. The tape may have a plurality of data tracks extending in the longitudinal direction. More recently, tape drive systems have used a track following servo system for moving the tape head in a lateral direction for following lateral movement of the longitudinal tracks as the tape is moved in the longitudinal direction. The track following servo system may employ servo tracks on the tape which are parallel to the data tracks, and employ servo read heads to read the servo tracks to detect position error and thereby position the tape head at the data tracks and follow the data tracks. This allows the data tracks to be placed closely together and increase the number of data tracks.
The tape is typically contained in a cartridge of one or two reels, and the tape is moved between a supply reel and a take up reel. The reels typically have runout causing the tape to move laterally as the tape is moved longitudinally. Tape guides provide the conventional means for limiting at least the amplitude of the lateral movement of the tape so that it does not exceed the lateral movement capability of the track following servo system.
Typical tape guides may comprise stationary buttons or edges, or flanges at the side of tape guide rollers, positioned against the edges of the tape to control the amplitude of the lateral movement of the tape. In order to increase the total capacity of a tape, the tape is increasingly made thinner to allow more wraps of tape to fit on a given tape reel. As a result, the tape is very weak in the lateral direction, and can easily be damaged at the edge from the tape guide. Thus, the tape guides are typically positioned at a bearing where the tape assumes a cylindrical shape, thus increasing the tape edge ability to support a load. The bearing is also typically designed to have low friction. This arrangement minimizes the potential to distort the edge of the tape as the guides push against the edges of the tape to move the tape to the center of the bearing to reduce the amplitude of lateral displacement of the tape. One example is illustrated in U.S. Pat. No. 5,447,279, which employs an air bearing to reduce the friction of the bearing for stationary tape guides. Roller bearings may also be utilized for reducing the friction of the bearing while the flanges of the roller bearings push against the edges of the tape. One example of a roller bearing or fixed pin with flanges arranged to have low friction is U.S. Pat. No. 4,427,166. Fixed surfaces may also be arranged to have low friction. One example is described in U.S. Pat. No. 4,466,582, where a synthetic resin or metal coated tape guide bearing has a reduced contact area for the tape to lower the friction between the guide surface and the running tape and allow the flanges to stabilize the tape.
However, when wound on a reel, tape is typically subjected to stack shifts or stagger wraps, in which one wrap of the tape is substantially offset with respect to an adjacent wrap. Thus, as the tape is unwound from the reel, there is a rapid lateral transient shift of the tape. Other common sources of rapid lateral transient shifts include 1) a buckled tape edge in which the tape crawls against a tape guide flange and suddenly shifts laterally back down onto the bearing, 2) a damaged edge of the tape which causes the tape to jump laterally when contacting a tape guide, and 3) when the take up reel or supply reel runout is so significant that the reel flange hits the edge of the tape.
As mentioned above, a servo read/write head positioning drive is now typically incorporated into the tape drive system in order to position the head precisely relative to a moving data track on tape. To provide the locational control of the servo read/write head positioning drive, a magnetic read head gap may be placed at a position relative to a servo track on the tape. Then the read head gap is further moved to detect the edge of the servo control track (servo track) recorded on the tape. The read head will provide signals which may be used to indicate the head location relative to the servo track. By using these signals as a basis, the servo control then may produce a positioning signal to drive a servo positioner. The servo positioner moves the read head, causing the read head to track or follow the edge of the servo control track which has been previously recorded on the tape.
The transient response of the tape head track following servo system typically comprises a high bandwidth for a very limited lateral movement, called "fine" track following, for allowing the tape head to accurately follow small displacements of the tape. Larger movement of the tape head is typically conducted as "coarse" track following, which is also employed to shift the tape head from one set of tracks to another set, and is conducted at a slow rate. The occurrence of a lateral transient shift, however, is so rapid that neither the fine track follower nor the coarse track follower is able to respond, with the result that the tracking error becomes so large that writing must be stopped to prevent overwriting an adjacent track and to insure that the tracking error on read back is not so large as to cause a readback error.
One approach has been to make the tape guide edges or flanges closer together to maintain a pressure on both edges of the tape. However, this tends to stress and damage the edges of the tape, reducing its durability. An attempt at reducing the stress comprises spring loaded tape guides, such as the above-mentioned '279 patent. However, although the amplitude of the tape shift may be reduced somewhat by this approach, the speed of the shift is typically not reduced, and the track following servo error still occurs, reducing the performance of the tape drive.
Various attempts have been made to compensate for tape shifts. For example, a tape movement constraint is provided for a tape drive system which moves a tape longitudinally along a tape path across a tape head, the tape having longitudinal tracks and a tape roller bearing is positioned closely adjacent the tape head. The tape roller is rotatable about a central axis parallel to the cylindrical peripheral surface, allowing the tape freedom of movement in the longitudinal direction. The tape roller bearing has a frictional cylindrical peripheral surface for contacting and engaging the surface of the tape and constraining movement of the tape in the lateral direction, thereby reducing the rate of the lateral transient movement of the tape to allow the track following servo system to follow the reduced rate lateral transient movement of the longitudinal tracks. Any potential air bearing that could form between the surface of the tape and the surface of the roller bearing is collapsed to insure that the roller bearing frictionally contacts and engages the surface of the tape.
Nevertheless, a problem is associated with a tape drive that uses a spiral grooved roller tape guide for controlling lateral tape motion transients in the tape path. The grooved roller has the tendency to bias the media toward the direction of forward spiral. This creates offsets in the tape guiding position that depend on the direction of tape motion. For example the tape is biased down to the bottom flange when the guide is rolling clockwise and biased to the top flange when the guide is rolling counter clockwise. This biasing of tape results in relatively large lateral displacement between forward and backward direction and in the tape drive. This movement could shift the tape servo format completely off of the servo head element resulting in loss of servo signal and ultimately failure in acquiring track lock.
It can be seen that there is a need for a method and apparatus for compensating for media shift due to tape guide.

Method and apparatus for compensating for media shift due to tape guide

International Business Machines Corporation


An X-ray imaging apparatus comprises an X-ray source; a housing configured to accommodate the X-ray source; and a plurality of supporting legs each connected to the housing via a movable connecting portion and configured to support the housing, wherein each of the supporting legs can change, by the movable connecting portion, a support angle made by a ground plane and the supporting leg.

1. Field of the Invention
The present invention relates to an X-ray imaging apparatus.
2. Description of the Related Art
In recent years, X-ray imaging aiming at medical diagnosis or the like is used in emergency treatment, at a site of disaster, or the like by reducing the size and weight of an X-ray imaging apparatus including an X-ray source and increasing the portability. Japanese Patent Laid-Open No. 2011-56170 discloses a technique of using an X-ray imaging apparatus vertically hung above the inspection part of an object by a collapsible holder. Japanese Patent Laid-Open No. 2008-79728 discloses an X-ray imaging apparatus including an X-ray shield member that restricts the irradiation range of X-rays emitted by an X-ray source to irradiate an object, and a driving unit that is connected to the X-ray shield member to increase/decrease the X-ray shield area of the X-ray shield member.
However, the X-ray imaging apparatus as disclosed in Japanese Patent Laid-Open No. 2011-56170 necessitates labor and time for assembly and installation of the holder at the time of X-ray imaging. In addition, there is a problem of portability because the X-ray imaging apparatus and the holder are separate. The X-ray imaging apparatus as disclosed in Japanese Patent Laid-Open No. 2008-79728 can neither improve the portability nor facilitate installation.


A belt type fixing device of the invention comprises a fixing belt, a heating panel, a pressure member, and a pressure roller. The heating panel has a curved outer surface in sliding contact with the inner surface of the fixing belt and a curved inner surface on which a resistance heating band element is formed. The resistance heating band element is formed in a zigzag pattern with a plurality of stripes perpendicular to the direction in which the fixing belt moves. The pressure member gives tension to the fixing belt in cooperation with the heating panel and has an elastic body in sliding contact with the inner surface of the fixing belt. The pressure roller rotating in a predetermined direction applies pressure to toner carrying recording paper led into a nip formed by the pressure roller and the pressure member.

1. Field of the Invention
The present invention relates to a belt type fixing device which is used to fix toner in an electrophotographic imaging apparatus such as a photocopier, printer, or facsimile.
2. Description of the Related Art
A conventional fixing device in an imaging apparatus typically used a pair of rollers to heat and press a recording sheet carrying toner. However, as color imaging apparatuses have spread, a belt type fixing device which heats the nip adequately and may be compact has been proposed.
In the belt type fixing device, usually a belt wound and put between two rollers is heated at a point away from the nip and the heat given to the belt is transferred to unfixed toner through circular movement of the belt. In this structure, a heat source need not be located at the nip, more specifically inside a fixing roller, as in the conventional fixing device, so a low-hardness elastic layer with a low thermal conductivity may be provided at the nip. The use of such a low-hardness elastic layer assures a wider nip.
One example of this type of belt type fixing device is disclosed in Japanese Patent Laid-open No. H08-137306. In this prior art, a fixing belt is put between two rotary rollers and an electromagnetic induction coil is located on the belt between the rollers to heat the belt directly. Since these rollers need circularly rotate the belt with a tensile force, they must have a relatively high strength and thus the rollers should have a relatively large thermal capacity. Hence, some of the heat of the belt spreads to the rollers. Since the rollers absorb some of the heat of the belt because of the large thermal capacity in this way, it is difficult to shorten the warming up time further even though the heating efficiency is improved by electromagnetic induction.
Another example is the method disclosed in Japanese Patent Laid-open No. H05-107961 whereby a heating body is in sliding contact with the outer surface of a heating roller in order to shorten the warming up time. Since the sliding contact surface is a fixing plane and vulnerable to scratching, there is the problem of low durability.
Also, there have been attempts to provide anon-rotary heater at the nip for direct heating. In this case, however, the heater must have both a heating function and a pressing function, so it is difficult to provide a wider nip and the heater holder and the heater must be manufactured with a high dimensional precision and accurately assembled, which increases the manufacturing cost.