A photoacoustic sensor (100) is capable of detecting a predefined target gas in an area (Um). A process is capable of detecting the target gas with the use of such a sensor (100). A sample chamber (3) holds a gas sample (Gp) to be tested. Electromagnetic waves (eW) from a radiation source (1) pass through the sample chamber (3) and the detection chamber (4). The waves elicit in the detection chamber (4) an acoustic effect, which is measured by an acoustic sensor (7). The acoustic effect is correlated with the concentration of the target gas in the sample chamber (3). The detection chamber (4) is fluid-tightly sealed, is free from target gas and is filled with a replacement gas (Eg). The transmission of the replacement gas (Eg) has a spectral response similar to that of the transmission of the target gas in a predefined target gas wavelength range.

Various photoacoustic sensors have become known.
DE 10 2012 217 479 B3 describes a gas sensor 1, which is capable of determining the concentration of a target gas in a gas mixture, namely, the concentration of a hydrocarbon, especially methane, in the exemplary embodiment described there. A test gas volume 11 is capable of accommodating a gas sample containing the target gas. A fluid-tight reference gas volume 12 with a housing 120 holds a mixture of the target gas and a buffer gas. The buffer gas improves the speed of response or the sensitivity or the accuracy of the gas sensor 1. For example, the buffer gas has a gas mixture between 1% and 20% and is, for example, sulfur hexafluoride (SF6). A radiation source 3 emits narrow-band or broad-band electromagnetic radiation 30. The radiation 30 passes through the test gas volume 11 and the reference gas volume 12. The radiation 30 elicits in the reference gas volume 12 an acoustic effect, and a resonance body 2 consisting of a piezoelectric material or a microresonator 20 is capable of measuring the acoustic effect.
A photoacoustic sensor, which measures the concentration of carbon dioxide (CO2) in the ambient air, is described in a document of the Fraunhofer-Institut für Physikalische Messtechnik (IPM) entitled "Miniaturized Photoacoustic Gas Measuring Systems," available under https://www.ipm.fraunhofer.de/content/dam/ipm/de/PDFs/produktblaetter/GP/ISS/photokustisehe-gas-messysteme-miniaturisiert.pdf, downloaded on May 18, 2020. A thermal emitter emits modulated electromagnetic waves in the infrared range into a measuring path. The IR waves pass through the measured path and impact a detection chamber, which is likewise filled with carbon dioxide and optionally with an admixture of noble gases. A microphone at the detection chamber detects an acoustic effect in the form of pressure fluctuations, which are generated by the modulated waves. The gas in the detection chamber absorbs a part of the IR waves. The absorption in the measured path is more intense and a signal generated by the microphone is consequently weaker when the ambient air in the measured path has a higher concentration of CO2.
Requirements imposed on an anesthesia workplace are listed with reference to EN740 in H. Gehring: "Monitoring of Ventilation During Anesthesia," Volume 27: Refresher Course, Current Knowledge for Anesthesiologists, Deutsche Akademie für Anästhesiologische Fortbildung, 2001, pp. 81-105. The anesthetic gas concentration is to be measured in the gas fed by inhalation, in the patient port or in the Y-piece at the tube. For example, photoacoustic spectroscopy is used for this purpose. Infrared light of a defined wavelength is sent in a pulsed form through the measuring chamber, as a result of which a "characteristic gas" is excited. The absorption of the light brings about changes in temperature, the latter lead to an increase in volume, and this in turn leads to pressure fluctuations, which are detected as sound waves and are processed electronically. Gases and gas concentrations can be measured hereby. N2 can also be detected.
A photoacoustic sensor is also described in M. El-Safoury: "Miniaturized photoacoustic detection of organofluorine-based refrigerants," Journal of Sensors and Sensor Systems, Vol. 9, Mar. 5, 2020, pp. 89-97.
A device and a process for the in-situ calibration of a photoacoustic sensor are described in DE 10 2016 216 875 A1. Calibration information that is obtained during the operation of the photoacoustic sensor is used for this purpose.

Photoacoustic sensor with replacement gas and detection process using such a sensor


Methods are disclosed for grouping search results into a profile page. A search engine accepts a user search string and generates a first set of results. In response to the first set of results, a query generator generates queries corresponding to a number of entities sharing a common name. The search engine executes the queries, returning responsive data sets. An entity resolver merges the data sets to ensure that each unique entity is represented by a single data set. A threshold may be defined such that results meeting a certain level of similarity are merged. A profile generator creates a profile page for each unique entity using biographical data contained in the respective datasets and generates a results page containing links to each unique profile. The results page is then sent to the user for display on a graphical user interface.

Embodiments of the disclosure relate to the field of search engines. More specifically, embodiments of the disclosure relate to generating a specific profile page for each unique entity sharing a common name with other entities, and presenting links to each profile page as a list of search results responsive to a user search string specifying the common name.

This patent is subject to a terminal disclaimer.

Grouping search results into a profile page

International Business Machines Corporation


An adjustable radial piston machine (pump or motor) is described whose drive mechanism (10) has a comparatively compact structure and an especially good mechanical efficiency. The drive mechanism (10) has a bearing ring (19) which is arranged concentric to a rotor (11) and which can be swung or pivoted about a symmetry axis (Q,H) different from its rotation axis for adjustment of the radial piston machine. An adjusting device (22) for pivoting the bearing ring extends axially parallel to the bearing ring (19) and acts on a facing surface of the bearing ring (19). Working pistons (13) guided in the cylinders in the rotor perform two motion cycles per revolution of the rotor, which are equal, but in opposite directions, over respective 180.degree. angular intervals. Cylinders (12) on opposite sides of the rotor are acted on by identical pressures so that the forces on the rotor are balanced and the rotor rotates largely free of friction.

The present invention relates to an adjustable radial piston machine, especially a pump or motor, and, more particularly, to an adjustable radial piston machine comprising a housing having an interior space, a drive mechanism arranged in the interior space and comprising a rotor coupled nonrotatably to a drive shaft or driven shaft outside the housing and provided with a plurality of radially arranged cylinders and working pistons movable in the respective cylinders, a stationary control pivot on which the rotor is rotatably mounted and which is provided with at least one feed duct and/or at least one outlet duct opening into respective control cavities, a bearing ring surrounding the rotor on which the working pistons bear and an adjusting device with which the bearing ring cooperates for adjustment of the operation of the radial piston machine.
A radial piston machine of this type is for example described in German Patent Application DE 41 43 152.9 A1. This radial piston machine has a drive mechanism, which is formed by a rotatably mounted rotor including radially arranged working cylinders. Pistons are guided movably in the working cylinders, which bear on a bearing or piston ring, which surrounds the rotor. The bearing ring is movable as a whole in a straight line relative to the housing for adjustment of the radial piston machine and cooperates with a hydraulic piston-cylinder device for that purpose. The eccentricity present between the bearing ring and the rotor is appropriately adjusted by an appropriate control of the hydraulic piston-cylinder device and thus the operating parameters of the radial piston machine are changed.
The disadvantage to this prior art arrangement is that the hydraulic forces on the rotor produced by the operating cylinders during operation of the radial piston are not balanced. Because of that the rotor bearings are loaded with frictional forces which impair the mechanical efficiency of the radial piston machine. Moreover the frictional forces lead to heating and/or to wear which in the extreme case can lead to seizing and/or to mechanical destruction of the drive mechanism components.


The invention relates to a method for the quantitative determination of a chemical substance S from a sample using a mass spectrometer having at least one detector. In line with the invention, a sample which may contain the substance S of interest, or a conversion product of the sample, is analyzed in the mass spectrometer. For the analysis the mass spectrometer is alternately set at least for masses SM1, SM2, so that each of the masses is detected multiple times and all of said masses are detected by the same detector. The masses SM1 and SM2 are fictitious neighboring masses for a mass CM of the substance S with a particular isotope content. The quantity of the mass CM is ascertained by means of calculation from the measured values for the masses SM1, SM2.

By way of example, quantitative analyses are performed in order to determine toxic or otherwise undesirable substances, such as halogen compounds. In this case, the aim is to ascertain the proportion of a particular substance—or substance class—within a sample, for example in micrograms per gram (=ppm) or nanograms per gram (=ppb).
The sample or a conversion product thereof can be temporally resolved using a chromatographic method, so that the sought substance in the eluate is in available at the outlet of the chromatographic device for analysis by mass spectrometry.
The mass spectrometer may have the usual design, namely with an inlet system, an ion source, a mass analyzer, a detector and a data system. The eluate from the chromatographic method is supplied to the inlet system of the mass spectrometer.
It is also possible to perform mass spectrometric analysis without a preceding chromatographic method. This frequently results in a greater level of uncertainty in the results. The sample or a conversion product thereof is supplied, directly to the inlet system of the mass spectrometer.
Numerous substances in an organic sample—such as pollutants, valuable nutrients or other target substances—have complex molecular structures with mass-to-charge ratios of more than 100 or more than 250, in particular. Depending on the elements contained, each substance has its own characteristic isotope pattern. It is therefore possible for the mass spectrometer to be used to detect various masses with a different respective isotope content for the same substance. In this case, the various masses of the same substance are in a relatively constant ratio with one another which is characteristic of said substance. It is therefore also possible to take the quantitative determination of a single target mass or of few target masses of the sought substance and to determine said substance quantitatively overall.
For the substances which are sought, the isotope patterns and accordingly also the various (exact) masses and the proportions thereof are known generally. The user knows what he is looking for and can therefore use the known isotope pattern to choose the masses of the sought substance which are able to be detected best.
An example of the method on which the invention is based and the methodology relating thereto are described in a document from the US environmental authority EPA (Environmental Protection Agency). The document is available on the Internet at http://www.epa.gov/region03/1613.pdf. It explains the quantitative determination of specific dioxins and furans by isotope dilution in conjunction with gas chromatography and mass spectrometry. The document and the method disclosed therein are cited as EPA 1613.
The principle of the isotope solution technique is that one or more "internal standards" (i.S.) are added to a sample before the further conditioning. These are usually isotope-marked by substitution of all C atoms for 13C isotopes. In this case, the internal standard is thereby 12 units of mass heavier than the analyte referred to as "native". The known admixture of the internal standard with the sample can be used to determine the content of the sought "native" analyte in the sample by forming a ratio between the measured value for the "native" analyte and the measured value for the internal standard. Normally, the most toxic dioxins are added as the internal standard and directly quantified by means of comparison. In addition, further dioxins found or fragments thereof which are formed in the ion source are frequently quantified simply as a sum. If appropriate, further standards are added after the sample conditioning in order to quantify the efficiency of the sample conditioning.
The invention is not limited to the determination of the cited pollutants. In principle, it is possible to determine any target substances contained in a sample using the method according to the invention.
Besides the substance which is being sought, the sample normally contains further known or unknown substances. The masses and dwell times thereof may be close to those of the substance which is being sought. The measured values for the selected masses of the sought substance can therefore be distorted by interference with other parts of the sample.
Interference between adjacent masses is visible during mass spectrometric analysis depending on the resolution of the mass spectrometer and the peak width of the respective mass. The area below the peak of the analyzed mass is a measure of the quantity of sample containing said mass. If a peak for an adjacent mass now coincides with the peak of the selected mass of the sought substance, the result is an excessive measured value for the selected mass of the sought substance, since for the selected mass not only the ions of the sought substance but also ions of the adjacent mass are included in part. The user usually does not know beforehand whether such interference is present and how great the interference is. This applies to appliances with only one detector as well as to multicollector mass spectrometers with a magnetic sector.
In order to prevent interference and hence to confirm an expected isotope pattern, it is sufficient for many applications if the ratio of two dominant mass peaks relative to one another is determined. At the same time, the target substance is often quantified only using one of the two mass peaks. For this reason, it is usual to refer to one mass (one mass peak) as the quantification mass QM and to the other mass (the second mass peak) as the comparison mass RM. This type of nomenclature is also used subsequently if appropriate for reasons of clarity. Naturally, it is possible and in many cases also expedient for both masses QM and RM to be used for the quantification. Accordingly, the terms "quantification mass QM" and "comparison mass RM" are not intended to restrict the scope of protection of the invention.
In order to detect the interference, DE 103 51 010 A1 (corresponding to WO 2004/047143) discloses the practice of splitting an ion beam into two separate ion beams using a reflecting electrode in the direction of the mass dispersion. The separate ion beams formed in this manner are directed at two separate detectors. If the signals from the two detectors differ significantly, the ion beam (before the split) has interference ions. This method requires additional hardware, namely the reflecting electrode and an additional detector. It is also necessary for the additional electrode to be aligned extremely precisely in order to ensure clean and even splitting of the ion beam. The two detectors need to be calibrated to one another. In addition, the division of the ion beam and the division ratio are permanently present.

Method for quantitatively identifying a substance by mass spectrometry


A modular bulkhead assembly is provided for a convertible roof system for an automobile. The convertible roof system is mounted to the bulkhead or wall member including left and right linkage assemblies, an electronic control unit, and a hydraulic control system. The bulkhead module can then be assembled into a vehicle as a modular unit. The electronic control unit can then be connected to the vehicle power supply by connection of wire harnesses from the electrical control unit.

Rigid hard-top convertible roofs have been used on a variety of motor vehicles. Some of these conventional convertible hard-top roofs are stored in a generally vertical orientation, and some are stored in a predominantly horizontal orientation. Furthermore, some of these conventional hard-top roofs fold in a clam shelling manner while others are collapsible in an overlapping manner. Most convertible hard-top roofs, however, employ a complicated linkage arrangement to couple the forward most hard-top roof section to either the vehicle body or the rear hard-top roof section. This is often due to the weight and moment arm effect of the front roof section during retraction. For example, many of these known mechanisms use an elongated balance link coupling the body to the front roof section, or an elongated sliding or track guide secured to the vehicle body and coupled to a link. Notwithstanding, such mechanisms may pose packaging and assembly obstacles in the typically tight confines of the vehicle body. The additional time required for assembly of these complicated linkage assemblies into a vehicle can substantially affect the cost of a vehicle having a convertible roof.
Examples of traditional hard-top convertible roofs are disclosed in the following patents: U.S. Pat. No. 5,979,970 entitled "Roof Assembly for a Convertible Vehicle" which issued to Rothe et al on Nov. 9, 1999; U.S. Pat. No. 5,785,375 entitled "Retractable Hard-Top for an Automotive Vehicle" which issued to Alexander et al on Jul. 28, 1998; U.S. Pat. No. 5,769,483 entitled "Convertible Motor Vehicle Roof" which issued to Danzel et al on Jun. 23, 1998; U.S. Pat. No. 5,743,587 entitled "Apparatus for Use in an Automotive Vehicle Having a Convertible Roof System" which issued to Alexander et al on Apr. 28, 1998; and EPO Patent Publication No. 1 092 580 A1 which was published on Apr. 18, 2001, each of which is herein incorporated by reference.

Bulkhead module for an automotive vehicle having a convertible roof


A cogeneration system of the present invention includes: an electric power generator (5); a cooling circuit (10) configured to cool the electric power generator (5) with a first heat transfer medium; a heat exchanger (16) provided on the cooling circuit (10); an exhaust heat recovery circuit (12) through which a second heat transfer medium that exchanges heat with the first heat transfer medium via the heat exchanger (16) flows; a heat storage unit (20) connected to the exhaust heat recovery circuit (12) and configured to store the second heat transfer medium that has undergone a heat exchange by the heat exchanger (16); and a controller (21), wherein a first temperature sensor (17), and a heater to which electric power is supplied from the electric power generator (5), are connected, in this order, downstream of the heat exchanger (16) in a direction in which the second heat transfer medium flows, and the controller (21) controls a flow rate of a circulating pump (13) so that, based on a temperature detected by the first temperature sensor (17), the detected temperature becomes a predetermined target temperature. In addition to preventing water temperature decrease in heat recovery and ensuring safety, this configuration can keep water temperature high at all times.

A conventional cogeneration system is disclosed in, for example, Patent Reference 1. FIG. 7 is a block diagram illustrating an overview of the configuration of the conventional cogeneration system.
As illustrated in FIG. 7, this cogeneration system 500 comprises an exhaust heat exchanger 54, a heater 56, a heat exchanger 57, and an exhaust heat pump 55, which are connected in series by an engine exhaust heat recovery circuit 51. The exhaust heat exchanger 54 is connected to an exhaust passage 53 of a gas engine 52 serving as an electric power generator. A hot water storage tank 59 (heat storage unit), a heat exchanger 57, a circulation temperature sensor 61, and a circulating pump 60 are connected in series by a hot water passage 58. The heat exchanger 57 is configured so that a heat exchange can be performed between water (first heat transfer medium) in the engine exhaust heat recovery circuit 51 and water (second heat transfer medium) in the hot water passage 58.
The following describes an operation of the cogeneration system 500. An electric power generator (not shown) provided therein, which is driven by the gas engine 52, generates electric power and supplies it to a household or the like. The heat produced by the generation of electric power is transferred to the water in the engine exhaust heat recovery circuit 51 via the exhaust heat exchanger 54 connected to the exhaust passage 53. The exhaust heat pump 55 causes the water in the engine exhaust heat recovery circuit 51 to circulate, whereby the heat recovered with the exhaust heat exchanger 54 is transferred to the water in the hot water passage 58 via the heat exchanger 57. The circulating pump 60 causes the water in the hot water passage 58 to circulate, whereby the heat recovered by the heat exchanger 57 is stored in the hot water storage tank 59 in the form of hot water. This configuration makes it possible to use the electric power generated by the gas engine 52 and simultaneously to use the hot water stored in the hot water storage tank 59 for hot water supply or heating in the household or the like, thereby serving the function as a cogeneration system.
Next, the following describes the water temperature controlling method of the cogeneration system 500. The water in the hot water passage 58 is heated by the heat exchanger 57, and at this time, the circulation flow rate of the circulating pump 60 is controlled so that the water temperature detected by the circulation temperature sensor 61 becomes a target value (for example 70° C.) that is the highest temperature that can be recovered. For example, the following feedback control is performed; if the amount of heat transferred by the heat exchanger 57 from the engine exhaust heat recovery circuit 51 becomes less (specifically, the temperature detected by the circulation temperature sensor 61 becomes less than the target value), the flow rate of the circulating pump 60 is reduced so that the temperature detected by the circulation temperature sensor 61 can be kept at a high temperature. The water heated by the heat exchanger 57 is supplied into the hot water storage tank 59 from an upper part of the tank. The water supplied to the heat exchanger 57 is taken out from a lower portion of the hot water storage tank 59. By such a water temperature controlling method, the interior of the hot water storage tank 59 performs what is called "stacked heating", in which high-temperature hot water is stored in the upper part. With this system, the water temperature in the upper part can be kept high even when the entire water in the hot water storage tank 59 is not at high temperatures. High-temperature hot water can be used at any time by taking out the hot water from the upper part. To make use of this feature, it is important to keep the temperature of the portion at the circulation temperature sensor 61 high at all times in the above-described water temperature controlling method.
On the other hand, when supplying the electric power generated by the gas engine 52 to the household or the like, the system is generally connected to a power supply system (not shown) built by, for example, an electric power company, so that what is called system interconnection is implemented. By the system interconnection, electric power is supplied from outside if the power loads of, for example, the household cannot be covered by the power generation capability of the gas engine alone. When the system interconnection is implemented, what is called an inverse load flow occurs, in which electricity flows toward the power supply side if the power loads of the household or the like is small relative to the power generated by the gas engine 52. To prevent this inverse load flow, the conventional cogeneration system performs a process in which excessive electric power is converted into thermal energy by passing electricity through the heater 56.
[Patent Reference 1] Japanese Laid-Open Patent Application Publication No. 2004-263589


A method of stabilizing a fluorine-containing acid amplifier. The method is provided to include the step of dissolving a fluorine-containing acid amplifier in an organic solvent thereby producing a solution of the fluorine-containing acid amplifier, the fluorine-containing acid amplifier being represented by general formula (1):

The present invention relates to a method of stabilizing a fluorine-containing acid amplifier.
With the recent development of digital devices such as computers, it has become common to process an enormous amount of operational data or two- or three-dimensional image data. There is a need to provide large-capacity high-speed memories and high-performance microprocessors for quick processing of such enormous information. Further, the processing power required of the digital devices is estimated to increase more and more as the broadband spreads with the development of network systems such as the Internet.
In order to meet this need, various devices such as semiconductor devices are required to achieve higher density and higher integration. The requirements for photolithography processes, which enable fine patterning, are particularly becoming more stringent year by year. For example, photolithography process using ArF excimer laser radiation (wavelength: 193 nm) has been put into use in response to the requirement for patterning techniques with a minimum line width of 0.13 μm or less for production of 1 Gbit or higher-capacity DRAMs. The development of photolithography process using extreme ultraviolet (EUV) radiation has also been pursued for finer patterning.
For the purpose of improving line edge roughness in these wavelength regions, studies of additives for photoresists such as photoacid generators had been eagerly made. In extreme ultraviolet (EUV) region, however, it is sometimes difficult to sufficiently improve line edge roughness only by photoacid generators because of poor energy from light source. In response to the increasing requirements for finer patterning by photoresist, there have been reported such fluorine-containing acid amplifiers as to form a secondary acid from acid generated by a photoacid generator thereby allowing improvement of line edge roughness of photoresist pattern (Non-Patent Publications 1 and 2).

Method of stabilizing fluorine-containing acid amplifier

The Research Foundation for the University of New York


A pulse generator for generating pulses for modulation onto a carrier or subcarrier of a composite television signal is provided. The pulse generator includes a memory such as an EPROM for storing one or more waveshapes. Each stored waveshape is defined by a sequence of addressable values representing the amplitude of the waveshape as a function of time. A selecting circuit such as a microprocessor selects one of the waveshapes in the memory. A counting circuit responsive to a clock signal controls the address lines of the memory to read the amplitude values corresponding to the selected waveshape from the memory. The amplitude values are supplied to a digital to analog converter to convert the amplitude values to an analog pulse. The pulse may then be filtered to remove clock noise. The resultant signal is supplied to an amplitude modulator for modulating the signal onto a carrier or subcarrier of a composite television signal.

1. Technical Field
The present invention generally relates to a method and apparatus of transmitting information in a television system and, more particularly, to a pulse generator including a memory for storing pulses for modulation onto a carrier or subcarrier of a composite television signal.
2. Description of the Prior Art
In conventional cable television systems, information may be transmitted from a headend location to individual terminal units in the system. This information provides a variety of information, for example, describing how a composite video signal is being scrambled, as well as other information useful to the terminal unit as is well-known in the art. Ways of transmitting such information include amplitude modulating the FM sound carrier, a subcarrier, or an out-of-band carrier signal with the information.
FIG. 1 illustrates adjacent NTSC television channels. Each television channel has a bandwidth of 6 MHz, within which a composite video and audio signal are transmitted. The video portion is transmitted as signals amplitude modulating a picture carrier and occupying 5.5 MHz of the channel, while the audio portion is transmitted in a 50 KHz band as a frequency modulated signal on a sound carrier 4.5 MHz above the picture carrier frequency. A color subcarrier is located 3.58 MHz above the video carrier. The sound carrier of the first channel is centered 0.25 MHz below the upper end of the second channel. It is important to ensure that when information is amplitude modulated onto the sound carrier of the first channel, interference with the second channel is not generated. The transmission of information by amplitude modulating a square wave pulse with its sharp transitions is desirable in terms of detection by a receiver. However, when the sound carrier of the first channel is amplitude modulated using the square wave pulses illustrated in FIG. 2A, the resulting spectrum 25 can be seen to interfere with the second channel. Wave shaping techniques may be used to reduce this interference. For example, the spectrum 30 generated by amplitude modulating the audio subcarrier of the first channel with the sine squared pulses illustrated in FIG. 2B does not significantly interfere with the second channel.
A circuit arrangement for amplitude modulating the sound carrier using the sine squared pulses of FIG. 2B is illustrated in FIG. 3A. The circuit arrangement includes a control circuit 40, a logic gate 45, a sine squared shaping filter 50, and an amplitude modulator 55. Control circuit 40 such as a microprocessor applies control signals to logic gate 45, such as a TTL gate, in accordance with the data to be transmitted. Logic gate 45 outputs square wave pulses in response to the control signals, one such pulse designated as 47. Square wave pulse 47 is supplied to sine squared shaping filter 50, such as a fourth order sine squared shaping filter, which shapes pulse 47 to a sine squared pulse 52. Sine squared pulse 52 has a sufficiently sharp transition to permit detection by receivers, but avoids the interference problems associated with rectangular pulses. Sine squared pulse 52 is supplied to audio modulator 55 which amplitude modulates the sine squared pulse onto an intermediate frequency sound carrier. The output of audio modulator 55 is supplied to a modulator (not shown) for generating a television signal suitable for transmission, for example, over a cable television system. A terminal unit in the cable television system receives the television signal and recovers the information amplitude modulated onto the sound carrier in order, for example, to descramble scrambled video information.
The amplitude modulation of pulses onto the sound carrier may also be used in an effort to defeat the ability of unauthorized or pirate terminal units from recovering the transmitted descrambling information to thereby obtain access to premium programming. Accordingly, pulses may be transmitted which unauthorized terminal units incorrectly detect as descrambling information, but which authorized terminal units ignore. This may be accomplished, for example, by transmitting pulses 40 and 42 as illustrated in FIG. 2C. Unauthorized terminal units may detect pulses 40 and 42 as timing pulses, thereby inhibiting the ability of the unauthorized terminal unit to recover the proper timing information necessary to descramble the scrambled picture. Authorized terminal units would ignore pulses 40 and 42. It will be appreciated that compatibility among various systems sensitive to data amplitude modulated on the sound carrier may be achieved if, for example, certain pulses modulated onto the sound carrier by a scrambler of a first system are not detected by receivers designed for use in a second system. Again referring to FIG. 2C, a scrambler designed to transmit data to a receiver of a first system may nonetheless be compatible with receivers of a second system if, for example, pulses 40 and 42 have an amplitude sufficient to be detected by receivers of the first system, but not by receivers of the second system.
Pulses such as those in FIG. 2C may be generated by the circuitry of FIG. 3B which includes control circuit 66, logic gate 67, pulse modification circuit 68, first and second sine squared shaping filters 70 and 72, timing control 75, gain adjustment circuit 80, and amplitude modulator 81. Control circuit 66 applies control signals to logic gate 67 in accordance with the data to be transmitted. Logic gate 67 outputs square wave pulses in response to the control signals. Pulse modification circuit 68 may be included to shift the level of the square wave since pulses of different amplitudes are to be generated. First and second sine squared shaping filters 70 and 72 shape the pulses. Gain adjusting circuitry 80 is utilized to adjust the gain of the signal in one path relative to the signal in the other path. Timing control 75 switches between the outputs of filters 70 and 72 at appropriate times. Amplitude modulator 81 modulates the pulses onto a sound carrier at an intermediate frequency. While such circuitry may be implemented, the timing control may be difficult to implement in practice and the sine squared filters must be specifically designed to defeat each different pirating technique or to achieve compatibility with each different system.
The amplitude modulation of signals on the sound carrier at the line rate of 15.734 KHz (f.sub.H) can also interfere with the second audio program (SAP) of a stereo transmission. The second audio program is modulated onto a subcarrier having a frequency five times the line rate f.sub.H. If a high quality demodulator is not utilized, AM to FM conversion of the energy modulated onto the audio subcarrier at the line rate f.sub.H can result in the false detection of a second audio program or, more likely, a distortion of the second audio program. This problem may be addressed, for example, by providing a notch filter in the receiver to remove the fifth harmonic of the signal modulating the sound carrier at the line rate. However, such an arrangement can be difficult to implement and further adds group delay to the filtered signal.

Pulse generator including a memory for storing pulses for modulation on a carrier of a television signal


A circuit arrangement that controls the increase in voltage output of an operating voltage source such that a voltage dip during connection (or reconnection after repair) of a pluggable unit remains higher than the minimum allowable value and controls the decrease in voltage output to a normal operating voltage after a predetermined time interval. The increase can occur manually by a switch or automatically thru the use of sensors.

The invention relates to a circuit arrangement for supplying an operating voltage to a number of connectable and detachable circuit units from an operating voltage source.
Connectable and detachable circuit units include circuits such as subscriber terminal circuits or groups of subscriber terminal circuits as used in telephone switching exchanges. Generally, a common voltage transformer supplies an operating voltage of approximately 5 volts to the circuit units.
In applications involving circuit units there is a need to exchange an older unit with a newer unit or connect additional units without disturbing the operation of the other existing units. Such additional connections are difficult, because the units also contain capacitors. The capacitors need to be charged. Therefore in the first moment of the connection, an increased load of the operating voltage occurs due to charging processes of the capacitors. In situations where the current efficiency of the voltage transformer is limited, the supply lines to the voltage transformers are not generally low-resistance, and a rapid compensation of the current surge cannot be carried out problem free, thus a dip in the operating voltage is expected. At a supply voltage of 5 V, a typical voltage dip lies in the range from 0.3 to 0.7 V, and the time duration lies in the microsecond (.mu.s) range.
Switching circuits used in the subscriber terminal circuits operate securely only in the range from 4.5 to 5.5 V. In this voltage range disturbances in the operation of the circuit units often occurs. A possible solution to this problem is to provide the circuit units with what is called a leading contact pin. A special voltage is applied to the leading contact during the connection and before the actual operating voltage is applied. The special voltage charges the capacitors of the unit in a delayed fashion. The special voltage is derived from the normal operating voltage and is supplied via a centrally provided inductor to the charge pulse.
In the unit itself, a diode decouples the mentioned special voltage from the standard operating voltage. This solution is undesirable because of the high costs associated with the special contacts, the central coil and the decoupling diodes.
If a decoupling diode is defective, i.e. it is short-circuited or interrupted, the operation of the circuit is adversely affected. Even in units that are not sensitive to the voltage dips, but cause such voltage dips, it is not possible to forego the mentioned individual measures if overall a combination of units existing in the system that are sensitive to operating voltage dips.

Circuit arrangement for supplying an operating voltage from an operating voltage source to a plurality of connectable and detachable circuit units


A method and apparatus for generating accurate estimates of a radar target's azimuth and elevation angles for a phased-phased array rotating radar. Scan modulated coherently integrated (SMCI) monopulse curves are generated from a measured one-way transmit antenna pattern and three receive antenna patterns. The SMCI monopulse curves are calculated in advance for the expected beam steers. To utilize the SMCI monopulse curves, two-way Sum, Delta-Azimuth and Delta-Elevation target returns are coherently integrated, the target's monopulse ratios calculated, and the SMCI monopulse curves or polynomials used to calculate the target's U-offset and V-offset sine-space angles, which are added to the radar's beam steer to get an improved estimate of the target's sine-space angular position denoted as Utgt and Vtgt. A coordinate system transformation transforms Utgt and Vtgt to azimuth and elevation angles in a non-rotating coordinate system.

1. Field of the Invention
This invention relates generally to a rotating phased-phased array radar, and in particular to a method of generating accurate estimates of azimuth and elevation angles of a radar target using pre-calculated monopulse curves for a rotating monopulse radar using coherent integration of pulse returns.
2. Description of Related Art
An antenna of a mechanically rotating radar moves in azimuth relative to a target as pulses are transmitted and received. As a result, the pulse returns are scan-modulated by the radar's two-way antenna patterns. In other words, the pulses experience dissimilar antenna pattern gains as the array rotates. Coherent integration of the pulse returns is done to increase the signal-to-noise ratios (SNRs) of the received signals prior to detection and target angle estimation. Non-rotating radars frequently employ the monopulse method for angle measurement. This process involves forming monopulse ratios and mapping those ratios to a target angle estimate using a pre-calculated monopulse curve or polynomial. The monopulse process has not been employed for rotating radars using coherent integration because the monopulse ratios do not map to the correct target angles when curves developed for a stationary array are used.
The performance of an angle estimation technique can be gauged by its beam-splitting ratio (BSR). The BSR is defined as the antenna pattern's two-way 3-dB beamwidth divided by the standard deviation of the angle error at 20 dB SNR. Previous rotating radars employing coherent integration, such as the U.S. Government's AN/SPS-49 Long-Range Air Surveillance Radar, have measured target azimuth angle using an algorithm to locate the centroid of the detected signal envelope. However, centroiding algorithms require multiple detections using mini-dwells and are characterized by small BSRs on the order of 2 to 4. The technique described herein is applicable for radars that want to coherently integrate the whole dwell for optimum performance and achieves BSRs on the order of 8 to 10 which is over twice the typical BSR of a centroiding
U.S. Pat. No. 5,017,927, issued May 21, 1991 to Ashok K. Agrawal et al., and assigned to General Electric Co. of Morristown, N.J., discloses a technique for using phase shifters and variable gain amplifiers within the transmit-receive (TR) processor of each antenna element to compensate for errors in the internal circuitry of the sum, azimuth difference and elevation difference beam formers. This invention is designed for a non-rotating radar and is an improved hardware implementation of the original monopulse method. However, it does not correct for the effects of rotation on a radar employing coherent integration (CI).
U.S. Pat. No. 5,986,605, issued Nov. 16, 1999 to Leslie A. Priebe et al., and assigned to Raytheon Company of Lexington, Mass., discloses a new method of monopulse processing that only requires two receiver channels and does not form the traditional monopulse ratios. The antenna is still subdivided into four quadrants. Quadrant pairs are formed from the top two quadrants, the bottom two quadrants, the left quadrants and the right quadrants. The signals received on the quadrant pairs are multiplied together to form two correlation beams. The estimated elevation and azimuth angles are the phase angles of the correlation beams. Target detection is performed by thresholding the magnitude of either correlation beam. This patent disclosure is an entirely new method of monopulse processing that was designed for a non-rotating radar, and does not correct for the effects of rotation on a radar employing CI.
U.S. Pat. No. 6,618,008, issued Sep. 9, 2003, to John Arthur Scholz and assigned to Nederlandse Organisatie of Delft, Netherlands, discloses a variation on the traditional monopulse antenna architecture. The antenna is still subdivided into four quadrants and the signals received on these quadrants are still summed, differenced and divided to form monopulse ratios. However, the antenna quadrants in this invention are not fixed in place. Instead, the quadrants rotate so that the difference pattern nulls are either aligned or perpendicular to the returns from the target tracks. The inventors claim these "virtual" quadrants reduce the complication and expense of the RF hardware required and allows the target to be tracked along any angle instead of the traditional azimuth and elevation angles. This invention is designed for a non-rotating radar and is an architectural variation on the original monopulse method. However, it does not correct for the effects of rotation on a radar employing CI.
U.S. Pat. No. 6,680,687 issued Jan. 20, 2004 to Michel Phelipot and assigned to Thales of Paris, France discloses a variation on the traditional centroiding algorithm used by 2-dimensional (2D) rotating radars for estimating target azimuth. A transmitted N-pulse burst is split into two N/2-pulse half-bursts. These half-bursts are then processed to associate a signal amplitude and azimuth angle with each half-burst. Coherent integration is used to determine amplitude and centroiding is used to determine azimuth. The two half-burst measurements of amplitude and azimuth are then combined using a mathematical formula to generate an improved estimate of target azimuth. However, coherently integrating half-bursts result in a factor N/2 improvement in SNR. Coherently integrating the entire N pulse burst, as the present invention does, results in a factor N improvement in SNR. Thus, the present invention achieves 3dB more SNR. Furthermore, U.S. Pat. No. 6,680,687 is intended for a 2D radar. A 2D radar measures only range and azimuth as opposed to a 3D radar which measures range, azimuth and elevation. The present invention will work for either a 2D or 3D radar and takes into account any cross-coupling between the azimuth and elevation measurements.

Method of generating accurate estimates of azimuth and elevation angles of a target for a phased—phased array rotating radar


In the method for configuration negotiation in a data communication system, an access network receives an access request and a token from an access terminal. The token includes at least one bit associated with a parameter group type, and the bit indicates whether the access terminal is operating according to a default parameter group for the associated parameter group type. The access network sends information to and receives information from the access terminal according to the default parameter group without negotiating a parameter group of the associated parameter group type when a portion of the access network communicating with the access terminal operates according to the default parameter group for the associated parameter group type and the bit indicates the access terminal operates according to the default parameter group for the associated parameter group type.

1. Field of the Invention
The present invention relates to the field of communication, and more particularly, configuration negotiation in a data communication system.
2. Description of Related Art
In a data communication system, access terminals (e.g., a mobile station, modem, etc.) communicate with an access network (analogous to the base station/mobile switching center network of a wireless communication system). Typically, parameters (e.g., parameters of communication protocols such as access protocols, power control protocols, etc.) governing the communication between the access terminal and the access network are communicated to access terminals over a control channel.
As the number of parameters required for the communication protocols increases, more control channel bandwidth is required. To save control channel bandwidth, some data communication standards have specified that some parameters should be communicated over a traffic channel. Each time an access terminal enters a new cell or sector of the access network or another access network, the parameters are negotiated because the portions of the access network serving different cells or sectors can operate according to different parameters. Unfortunately, this can significantly increase the time it takes to set up communication between an access terminal and the access network because instead of broadcasting the parameters on the control channel, the access network has to send parameters to individual access terminals. Specifically, in response to an access request from an access terminal, the access network must communicate each parameter to the access terminal over the traffic channel and wait for a response to each communication from the access terminal. The communication of messages from the access network and confirmation responses from the access terminal is called negotiation of the parameters.
As explained above, each parameter is negotiated. This can significantly increase the set up time, and may result in set up failures. Accordingly, a demand exists for a methodology to reduce the negotiation process and therefore the set up time.

Method for configuration negotiation in a data communication system


A storage tank having an inner vessel suspended within the outer vessel. One or more stiffening members support portions of the outer vessel. The use of the stiffening members limits deformation of the outer vessel due to the suspension of the inner vessel therein.

Typical multi-layered vacuum super insulated cryogenic tanks utilize a pair of cylindrical inner and outer tanks that are arranged concentrically with the inner tank residing in an interior of the outer tank. There are multiple radiant heat shields, approximately 30-80, coiled around the inner tank between the inner and outer tanks. A high vacuum exists between the inner and outer tanks to further prevent heat transfer. This type of thermal insulation is called a multi-layered vacuum super insulation. These storage tanks are capable of storing fluids at cryogenic temperatures.
The inner tank is positioned within the outer tank so that the inner tank does not contact the outer tank and so that thermal conduction paths between the inner and outer tanks are minimized. In one type of cryogenic storage tank, the inner tank is suspended within a central segment of the outer tank by four rigid tensile rods or sticks at each end that extend radially to central segment of the outer tank. The rods are individually preloaded to suspend the inner tank within the outer tank. The use of four rods on each end statically overconstrains the inner tank thereby resulting in an undefined stress distribution due to the preload and when the inner tank is loaded with a fluid. The extra rods also provide extra parasitic heat leaks. Furthermore, the use of the rods imparts localized stress concentrations on the central segment of the outer tank due to the suspending of the inner tank therein. The localized stress concentrations can deform portions of the central segment and impede the attachment of the end caps of the outer tank to the central segment.
Thus, it would be advantageous suspend the inner tank within the outer tank in a manner that does not impede the attachment of the end caps. It would also be advantageous if the suspending of the inner tank within the outer tank facilitated assembly of the storage tank.

Liquid hydrogen storage tank with radial stiffening


Surgical articles, implants and components suitable creating composite slings are described. Novel procedures for assembling and utilizing composite slings are also detailed.

Urinary incontinence is a significant health concern worldwide. Millions of people worldwide suffer from this problem. There are many different forms of incontinence. One of the most common is known as stress urinary incontinence (hereafter SUI).
A pubovaginal sling procedure is a surgical method involving the placement of a sling to stabilize or support the bladder neck or urethra. There are a variety of different sling procedures. Descriptions of different sling procedures are disclosed in U.S. Pat. Nos. 5,112,344; 5,611,515; 5,842,478; 5,860,425; 5,899,909; 6,039,686; 6,042,534 and 6,110,101.
Slings for treating incontinence may be constructed from synthetic materials such as polypropylene, polytetrafluoroethylene, polyester and silicone. Slings constructed from non-synthetic materials include allografts, homografts, heterografts, autologous tissues, cadaveric fascia and fascia lata. The strength and other properties of certain non-synthetic sling materials have been reported in the literature. See, Chaikin et al., Weakened Cadaveric Fascial Sling: An Unexpected Cause of Failure, Journal of Urology, Vol. 160, 2151 (December 1998); Choe et al., Autologous, Cadaveric, and Synthetic Materials Used in Sling Surgery: Comparative Biomechanical Analysis; Urology 58 (3), Pps. 482-86; 2001; and Lemer et al., Tissue Strength Analysis of Autologous and Cadaveric Allografts of the Pubovaginal Sling, Neurology and Urodynamics 18:497-503 (1999). While some non-synthetic sling materials are generally preferred by surgeons and patients, the quality of some non-synthetic materials (e.g. cadaveric sling material) varies greatly.
The supply of non-synthetic materials for slings varies greatly. Certain sizes of non-synthetic materials can be especially difficult to secure in a timely fashion. For example, autologous material may be difficult or impossible to harvest from some patients due to a variety of factors, including the health of the patient and the size of the tissue needed for a sling.
Some surgeons prefer synthetic materials, as they are readily available. The influence of various sling materials on tissue has been investigated. See Ulmsten et al., Intravaginal Slingplasty (IVS): An Ambulatory Surgical Procedure For Treatment of Female Urinary Incontinence, Scand. J. Urol. Nephrol 29: 75-82 (1995); Falconer et al., Influence of Different Sling Materials on Connective Tissue Metabolism in Stress Urinary Incontinent Women, Int. Urogynecol. J. (2001) (Suppl. 2): S19-S23; and Bent et al., Tissue Reaction to Expanded Polytetrafluoroethylene Suburethral Sling for Urinary Incontinence: Clinical and Histological Study, Am. J. Obstet. Gynecol., Vol 169, No. 5 Pps. 1198-1204 (1993).
Other relative advantages and disadvantages exist between non-synthetic and synthetic sling materials.
Some surgical procedures for incontinence utilize autologous tissue to provide a sling. See Aldridge, Transplantation of Fascia for Relief of Urinary Stress Incontinence, Am. J. of Obstetrics and Gynecology, v. 44, pages 398-411 (1948). There are significant recovery and morbidity issues associated with harvesting the sling material from the patient. See Sloane et al., Stress Incontinence of Urine: A Retrospective Study of the Complications and Late Results of Simple Suprapubic Suburethral Fascial Slings, J. of Urology, vol. 110, Pps. 533-536 (1973).
Some pubovaginal sling procedures extend a sling from the rectus fascia in the abdominal region, to a position below the urethra, and back again to the rectus fascia. Some slings are anchored in the abdominal fascia by virtue of suturing the sling material to the patient's abdominal tissue (e.g. rectus fascia). See Blaivas, Commentary: Pubovaginal Sling Procedure, Current Operative Urology, Edited by E. D. Whitehead, Philadelphia: J.B. Lippincott Co. Pp. 93-100 (1990) (biologic sling); and Moir, The Gauze-Hammock Operation, The Journal of Obstetrics and Gynaecology of the British Commonwealth, Vol. 75, No. 1, Pps. 1-9 (1968) (synthetic implant). Although serious complications associated with sling procedures are infrequent, they do occur. Complications include urethral obstruction, prolonged urinary retention, bladder perforations, damage to surrounding tissue, and sling erosion.
The Tension-free Vaginal Tape (TVT) procedure (available from Ethicon, of N.J.) utilizes a Prolene™ nonabsorbable, polypropylene mesh. The TVT mesh extends from the rectus fascia in the abdominal region, to a position below the urethra, and back again to the rectus fascia. No suture is recommended to tie the end of the mesh to the rectus fascia. Problems with the TVT procedure are documented in the literature and patents. See PCT publication nos. PCT WO 00/74613 and PCT WO 00/74594, U.S. Pat. Nos. 6,273,852; 6,406,423; and 6,478,727, and published U.S. Patent Application Nos. 2002-0091373-A1, 2002-0107430-A1, 2002-0099258-A1 and US-2002-0099259-A1. See also, Walters, Mark D., Percutaneous Suburethral Slings: State of the Art, presented at the conference of the American Urogynecologic Society, Chicago (October 2001) and PCT International Publication No. WO 02/26108.
Additional sling procedures are disclosed in Published U.S. Pat. Appl. Ser. No. U.S. 2001/0018549A1, and PCT Publication Nos. WO 02/39890 and WO 02/069781.
PCT Published Application No. WO 00/74633 discloses a tape for treating SUI. The tape is a combination of synthetic materials and a natural material centered between the synthetic materials. The natural material may be placed over or incorporated within a generally central portion of the synthetic material. The natural material may be connected to the synthetic material by sewing, a bio-compatible glue or cell culturing techniques.
Published U.S. Pat. Appl. Ser. No. 2002/0099260 discloses an implantable device or tape for use in correcting urinary incontinence. The tape includes sprayed polypropylene fibers that result in a strong implantable device. The tape also has a silicone-coated portion and tapered free ends.
U.S. Pat. No. 6,306,079 discloses a mesh pubovaginal sling comprising two pieces. One piece comprises a polypropylene mesh and a second mesh portion comprises an absorbable material such as poly-dioxanone. One piece may be inserted at the endopelvic fascia and the other in the suprapubic region. The two pieces are then connected via suture to support prolapsed organs so as to relieve urinary stress incontinence.
U.S. Pat. No. 6,355,065 discloses an implantable support that may be used in suburethral stabilization procedures for reducing stress incontinence. Ends of the support are folded to reinforce suture holes and to inhibit fraying or rupturing. Threading mechanisms may be provided to facilitate threading of sutures through suture holes. A removable, elongated clip may be placed on an intermediate portion of the implant to inhibit folding of the implant about its longitudinal axis. This document speculates that longitudinal folding of the implant could cause dead space in which bacteria could collect.
U.S. Pat. No. 6,042,534 discloses a stabilization sling for use in minimally invasive pelvic surgery. The sling may include reinforced suture receiving sites. Ends of the sling may be folded over to reinforce the sling.
PCT International Publication No. WO 02/28312 discloses a sub-urethral supporting assembly for treating female SUI. A junction part is disclosed for connecting two ends of a support tape.
Published U.S. Pat. Application Ser. No. 2002/0028980 discloses a Y-shaped implantable article for use in a sacral colpopexy procedure. Published U.S. Pat. Application Ser. No. 2002/0082619 discloses a reinforcing fastener guide for enhancing the functional longevity of an implant such as a sling.

Pelvic floor implant system and method of assembly


A method of allocating communication resources to terminals in an MF-TDMA telecommunication system is provided, in which digital data is transmitted in selected time intervals on each of a plurality of carriers. The resources for each terminal are allocated to frames grouped into superframes. The pattern of resources (time intervals and carriers) allocated to the terminal for the transmission of real-time data in each frame of a given rank in a superframe remains the same throughout the various superframes of the call relating to the real time data. Accordingly, the transmission of real time data is virtually free of jitter.

1. Field of the Invention
The invention relates to a method of allocating communication resources in an MF-TDMA telecommunication system, in particular, although not exclusively, a system using a transparent geosynchronous satellite.
2. Description of the Prior Art
It is known in the art that diverse types of communication resources, in particular frequencies, time slots and codes, can be used to transmit a multiplicity of digital calls simultaneously.
Multiple frequency time division multiple access (MF-TDMA) transmission, which uses a multiplicity of frequencies and time slots simultaneously, provides a high data bit rate. This is why it is used in the DVB-RCS standard, currently in preparation, which concerns the transmission via satellite of digital data (audio, video, Internet, etc.).
In the above type of telecommunication system, each carrier, which has a particular frequency, offers a given number of time slots per frame, the number of time slots per frame being equal to 1 or to a power of 2, for example (4, 8, 16, 32, 64, 128 time slots per frame).
Messages are transmitted in superframes containing a particular number of frames. A frame, which comprises a particular number of carriers and time slots, is transmitted during a particular time and a superframe extends over a number N of frame durations and includes a number N1 of carriers.
During a frame, the same message may be transmitted on several different types of carrier, that is to say with time slots of different duration.
As a general rule, MF-TDMA calls can be "star" calls, i.e. calls made through the intermediary of a base station. In other words, a terminal communicates with another terminal via the base station. It is also possible to effect calls directly between terminals, without passing through the base station, and this type of call is called a "meshed" call. It is also possible to combine star calls and meshed calls.
It has been found that, for real-time data, star or meshed MF-TDMA transmission can cause errors. In the case of video signals the errors can be visible and in the case of audio signals the errors can be audible. It has been found that these errors are the result of temporal instability (jitter), leading to inaccuracy in the times separating the various packets of the same call.

Method of allocating communication resources in an MF-TDMA telecommunication system


A hand tool includes a handle with a shank and a fixing member is connected to the shank. An isolation layer is coated on the outside of the shank and an annular groove is defined between the isolation layer and the fixing member. A socket has a lip having a positioning member to be engaged with a notch of the fixing member. A guide member is located beside the positioning member. A ring-shaped locking member is connected to the socket and has a recess with which the guide member is engaged. The locking member has two flexible blocks. A positioning member has a protrusion inserted into the through hole of the locking member and has a ridge contacting the lip of the socket. The protrusion has two passages, which are engaged with the two blocks. A bit is inserted into the reception hole of the positioning member.

1. Fields of the Invention
The present invention relates to a hand tool, and more particularly, to a hand tool with a connection device at the distal end of the shank so as to quickly connect a bit to the connection device, or release a bit from the connection device.
2. Descriptions of Related Art
The conventional screwdriver has a handle and a shank integrally extending from the handle, the shank has a function end such as the keystone tip, cabinet tip or Phillips head. However, each conventional screwdriver can only drives a specific type of the screw head. Therefore, the user has to carry multiple screwdrivers with him/her.
U.S. Pat. No. 7,467,575 B2 discloses a hand tool that has a handle, a fixing member, an adjustment member and a bit, wherein a reception hole is defined axially in the handle and the fixing member is fixed to one end of the reception hole to restrict the adjustment member. The fixing member has a positioning hole in which the bit is inserted. The fixing member has at least one slot communicating with the positioning hole. The adjustment member has a block which is inserted into the positioning hole via the at least one slot to position the bit. By operating the adjustment member, the block is removed from the positioning hole to release the bit. However, the connection device is located at one end of the handle and the bit is connected to the connection device, the length of the bit is limited so that the bit cannot reach the object at a deep hole.
The present invention intends to provide a connection device at the distal end of the shank so as to quickly connect a bit to the connection device, or release a bit from the connection device.

Connection device for connecting bit to hand tool


A hermetic package particularly adapted for high density interconnect (HDI) electronic systems employs a ceramic substrate which serves as a base for the hermetic package. The substrate comprises a cofired body including buried conductors which provide electrical continuity between a set of inner contact points and a set of outer contact points bridging a seal ring that comprises either a solder seal or a weldable seal for the hermetic package lid. The outer contact points may be directly connected to a leadframe. The leadframe leads, after severing, can be directly attached to a printed circuit board.

The present invention relates generally to integrated circuit packaging and, more particularly, to hermetically packaged electronic systems embodying a high density interconnect (HDI) structure.
Hermetically sealed packages have long been used to package semiconductor devices for use in high reliability systems and in hostile environments. A primary advantage of a hermetically sealed package for a sensitive electronic device or circuit is that the hermetic seal ensures that no outside contaminants or other deleterious materials can reach the sensitive device, component or circuit. This ensures that a device which, after hermetic sealing, meets specifications during testing, will not deteriorate as a result of contamination or the introduction of other deleterious materials. This assurance is particularly important in systems which must exhibit high reliability.
While production of a container for an electronic circuit which can be hermetically sealed does not seem, at first glance, to be a particularly complicated process, this initial perception can be misleading, especially when a new container configuration is required. Lead time for fabrication of a new container configuration normally runs at least 4-6 months and often more. If changes are required, the same period of time is needed for revisions. Consequently, when a new system is designed, it must either be designed to fit into an existing hermetic enclosure or substantial lead time must be provided for designing and fabricating the hermetic enclosure for that system.
As disclosed in Eichelberger et al. U.S. Pat. No. 4,783,695, and related patents, a high density interconnect (HDI) structure which has been developed by General Electric Company offers many advantages in the compact assembly of digital and other electronic systems. For example, an electronic system such as a microcomputer which incorporates between thirty and fifty integrated circuit chips, or even more, can be fully assembled and interconnected on a single HDI substrate which is fifty mm long, fifty mm wide and 1.27 mm thick.
This HDI structure can be disassembled for repair or replacement of a faulty component and then reassembled without significant risk to the good components incorporated within the system. Repairability is particularly important where fifty or more chips having a cost of as much as $2,000.00, each, may be incorporated in a single system on one substrate. This repairability is a substantial advance over prior interconnection systems in which reworking the system to replace damaged (i.e., faulty) components is either impossible or involves substantial risk to the undamaged (i.e., good) components. Exemplary testing and repair techniques are disclosed in Eichelberger et al. Pat. Nos. 4,878,991, 4,884,122 and 4,937,203.
Very briefly, in the manufacture of one embodiment of systems employing the aforementioned HDI structure, individual cavities (or one large cavity) having appropriate depths at the intended locations of the various chips are formed in a component-supporting surface of the ceramic substrate. The various integrated circuit chips and other components are placed in their desired locations within the cavities and adhesively attached to the substrate.
At this stage, the upper surfaces of all components and portions of the substrate component-supporting surface are disposed substantially in a common plane. A multi-layer high density interconnect (HDI) overcoat structure including interleaved layers of dielectric material and metallized conductive material is then built up to electrically interconnect the components into a functioning system.
The HDI overcoat structure typically does not extend all the way to the outer edge of the substrate component-supporting surface; rather, the overcoat structure terminates just inside a row of contact pads to which external connections are subsequently made, such as by ultrasonic wire bonding, when the system is finally assembled into a suitable leaded package. These contact pads are formed directly on portions of the substrate surface surrounding the cavities, and are electrically connected through suitable vias within the HDI overcoat structure to lower metallization layers of the HDI overcoat structure. Metallization deposited or otherwise formed directly on the ceramic substrate, as opposed to metallization layers within the HDI overcoat structure, is referred to as "metal zero".
This connection of the HDI electronic system into a separate leaded package, such as by conventional wire bonding, creates an additional interface, increases thermal impedance, and ultimately results in higher assembly costs than is achieved in accordance with the present invention.

Hermetically packaged HDI electronic system


An electrical assembly which includes a clip that couples a thermal element to an integrated circuit package. The integrated circuit package is mounted to a printed circuit board. An elastomer is located between the printed circuit board and the clip. The assembly is designed so that the elastomer applies a pre-load force which pulls the thermal element into the integrated circuit package. The pre-load is typically set so that the thermal element does not become separated from the package when the assembly is subjected to external shock and vibration loads. The elastomer applies the pre-load force uniformly along the area of contact with the printed circuit board. The elastomer does not create localized high stress points on the board. Additionally, the elastomer has an inner opening that is larger than the outer dimensions of the integrated circuit package so that the elastomer applies the pre-load force onto the board in an area away from the solder joints of the package.

1. Field of the Invention
The present invention relates to a clip assembly that couples a thermal element to an integrated circuit package and a printed circuit board.
2. Description of Related Art
FIG. 1 shows an electrical assembly of the prior art sold by Intel Corp. The assembly includes an integrated circuit package 1 that is soldered to a printed circuit board 2. The package 1 contains an integrated circuit (not shown) which generates heat. The assembly is provided with a thermal element 3 to facilitate the removal of heat from the package 1. The thermal element 3 is typically a heat sink which has a plurality of pins 4 that extend through the printed circuit board 2. The thermal element 3 is fastened to the circuit board 2 by a spring 5 that is attached to the pins 4. There are typically two springs in the assembly. The assembly is designed so that the springs 5 have a pre-load which pulls the thermal element 3 into the package 1. A thermal grease (not shown) is typically located between integrated circuit package 1 and the thermal element 3 to minimize the thermal impedance between the two components 1 and 3.
The assembly is typically incorporated into to a computer which may be subjected to external shock and vibration loads. It has been found that such external loads may create a physical separation between the thermal element 3 and the package 1. Any separation will increase the thermal impedance between the element 3 and the package 1 and increase the junction temperatures of the integrate circuit. Additionally, relative movement between the thermal element 3 and the package 1 may "pump" the thermal grease out of the thermal interface. The reduction in thermal grease also increases the thermal impedance of the package/thermal element interface and the junction temperatures of the integrated circuit.
The assembly is designed so that the springs 5 apply a pre-load which pulls the thermal element 3 into the integrated circuit package 1. The pre-load forces F are transferred into the printed circuit board 2 through a pair of support points of each spring 5. The load transfer points are located beneath the integrated circuit package 1. These point loads create localized high stress points which can crack some of the solder joints of the package. Cracked solder joints may create electrical shorts which effect the operation of the integrated circuit. It would be desirable to modify the assembly shown in FIG. 1 to prevent separation between the thermal element and the integrated circuit package and to minimize the stresses on the solder joints of the package.

GT clip design for an electronic packaging assembly


To increase the quantity of stored charges of memory cells by a simple configuration to improve the operating margin, and to allow dummy cells to be unnecessary to improve the operating margin of a DRAM without increasing the power consumption and/or the chip area. A voltage of a common plate line is changed from a first voltage to a second voltage lower than the first voltage while a word line is a third voltage which makes the word line a selected state. The voltage of the word line is changed into a fourth voltage which makes the memory cell a non-selected state and is lower than the third voltage and higher than a fifth voltage which makes the word line a non-selected state, and the voltage of the plate line is changed into the first voltage after the voltage of the word line has been changed into the fourth voltage.

1. Field of the Invention
The present invention relates to a memory cell array which is capable of increasing the quantity of stored charges of memory cells provided in a memory cell array of a DRAM (dynamic random access memory) by means of a simple configuration to thereby improve the operating margin of the memory cell array, and to a method of controlling such a memory cell array.
Priority is claimed on Japanese Patent Application No. 2007-163639, filed Jun. 21, 2007, the content of which is incorporated herein by reference.
2. Description of Related Art
There are known technologies to drive common electrodes (plate electrodes) of capacitors of memory cells provided in a memory cell array of a DRAM using pulses (i.e., a plate-driving scheme) to thereby substantially increase the quantity of stored charges (for example, see Patent Literatures 1 and 2, and non-Patent Literatures 1, 2, and 3).
Patent Literature 1: Japanese Unexamined Patent Application, First Publication No. S58-48294
Patent Literature 2: Japanese Unexamined Patent Application First Publication No. H 11-260054
Non-Patent Literature 1: K. Fujishima et al., "A Storage-Node-Boosted RAM with Word-Line Delay Compensation", IEEE Journal of Solid-State Circuits, Vol. SC-17, No. 5, October 1982
Non-Patent Literature 2: M. Aoki et al., "A 1.5-V DRAM for Battery-Based Applications", IEEE Journal of Solid-State Circuits, Vol. 24, No. 5, October 1989
Non-Patent Literature 3: T. Yamauchi et al., "High-Performance Embedded SOI DRAM Architecture for the Low-Power Supply", IEEE Journal of Solid-State Circuits, Vol. 35, No. 8, August 2000
In general, the use of the plate-driving scheme (which will be hereinafter simply referred to as "plate-drive") makes it possible to increase either one of the quantity of stored charges of a logic High ("H") signal and the quantity of stored charges of a logic Low ("L") signal. It is to be noted that, in the following description, the logic High ("H") will be simply referred to as "High", and the logic Low ("L") will be simply referred to as "Low" as the occasion may demand.
In related arts, a differential-input sense amplifier is used to sense the quantity of the stored charges which have been read out on a bit line and to amplify the quantity of stored charges, and thus a reference voltage is required for determining whether data which has been read out is a High data or a Low data.
Ordinarily, a reference voltage is set to the substantially middle voltage between the voltage of a bit line when a high level signal is read out thereon and the voltage of a bit line when a low level signal is read out thereon, thus ensuring the same sensing margins regardless of which data is read out. When the plate-drive is not performed, it is sufficient to use the middle voltage between the voltage of a high level signal on a bit line and the voltage of a low level signal on a bit line as a reference voltage. For example, such a reference voltage can be relatively easily generated by short-circuiting a bit line which has been amplified so as to be a high level and a bit line which has been amplified so as to be a low level.
However, when the plate-drive is performed, either the quantity of the stored charges of a high level signal or the quantity of the stored charges of a low level signal is increased. As a result, the reference voltage greatly shifts from the middle voltage. For this reason, in the related arts, dummy cells are added to generate a reference voltage.
For instance, in the related arts shown in FIG. 7 (FIG. 3 of the Patent Literature 1) and FIG. 8 (FIG. 3 of the non-Patent Literature 3), the quantity of stored charges corresponding to a Low data is increased by a plate-drive, and thus a reference voltage of a differential-input sense amplifier is adjusted by using a dummy cell such that the reference voltage is equal to a voltage which is substantially one half of the voltage when a High data is read out and the voltage when a Low data is read out.
However, there is the problem in that when dummy cells are used, current consumption for driving the dummy cells would be increased. Moreover, there is the problem in that the chip area is increased because dummy cells are disposed. Furthermore, there is the problem in that when the dummy cells become defective, the yield would be reduced because it is impossible to perform a remedy using a redundancy configuration.

Memory cell array and method of controlling the same


A tire pressure monitoring system includes a plurality of tire pressure monitoring devices mounted within corresponding tires that transmit information to a handheld receiver that is mounted and supported within a cradle of a vehicle cabin. The handheld device is removable from the cradle to reveal a primary display that communicates specific information regarding the conditions of the system and individual tires. The remote handheld device can also be utilized to prompt a tire pressure monitoring device to display temperature compensated pressure measurements in real time during tire inflation.

This invention generally relates to a tire pressure monitoring system. More particularly, this invention relates to a tire pressure monitoring system for a vehicle including a hand held monitoring device.
Current tire pressure monitoring systems require prior programming of tire position in order to properly identify a tire with a problem. Such prior programming is not a huge burden for vehicles with only four wheels. However, larger vehicles with multiple dual tire axles require greater effort to program, maintain and identify each tire pressure sensor with a tire position. Conventional systems may utilize additional antennas to determine tire position at increased cost and complexity. Other systems require a disciplined continual updating of tire position on the vehicle.
Additionally, tire pressure is a temperature sensitive variable that complicates even the simple process of inflating a tire to a proper pressure. The tire pressure monitoring sensors can compensate for temperature; however, during inflation instant access to the temperature compensated tire pressure is not available when the tire pressure readout is disposed within a vehicle cabin.
Additionally, current tire pressure monitoring systems continually gather data indicative of current tire conditions. Not all this data is required by the operator at all times. Only certain specific levels of data are required to be communicated to the operator dependent on current conditions and the preference of the vehicle operator.

Hand held tire pressure monitoring system


An integrated sensor includes a sensor cell, a signal source, an input optical rotator, and a signal detector. The integrated sensor includes a positioner for a signal-processing component. The positioner may be a linear positioner for the signal-processing component, such as a signal source or a signal detector, or may be a rotational positioner for the signal-processing component, such as a polarizer or a polarized signal source. The signal-processing component is located on a signal path of the integrated sensor. A method of adjusting a linear position or rotational position of a signal-processing component is also disclosed. A linear position or a rotational position of the signal-processing component may be adjusted to improve performance of the integrated sensor.

Integrated microfabricated alkali vapor sensors provide small form factors and low power operation, enabling atomic clocks and atomic magnetometers for mobile and unmanned applications. Reduced costs of the integrated microfabricated alkali vapor sensors have led to high volume assembly processes used for manufacturing electronic devices. These assembly processes often place components of the sensors, including signal sources and polarizers, in locations and orientations that have some positional issues and alignment issues. The issues may impact the performance of the sensors.

Component adjustment in a signal path of an integrated sensor


Methods and systems for fast variable block-size motion estimation based on merging and splitting procedures for AVC video encoding are disclosed. The methods take advantage of the correlation of the Motion Vectors (MVs) of the different block-size modes to achieve a good computation reduction. Considering that the smaller the block-size difference between two block-sizes is, the more correlations between their MVs can be expected, the methods use a 8*8 block as an initial processing block to calculate prediction MVs. The prediction MVs are then used in predicting MVs for other block-sizes.

1. Field of the Invention
The present invention relates generally to a method and system of variable block-size motion estimation and more particularly, to a method and system of fast variable block-size motion estimation based on merge and split procedures for H.264/MPEG-4 AVC video encoding.
2. Background of the Invention
In current video coding standards, Motion Estimation (ME) is a core functional block to remove temporal redundancy in video sequences to achieve high compression. In the emerging H.264/MPEG-4 AVC video coding standard, for Inter coded Macroblocks (MBs), tree-structured block-sizes can be employed in the motion estimation. Each 16*16 MB can be coded in 16*16, 16*8, 8*16, and 8*8 block-modes. If the 8*8 block-mode is chosen, each 8*8 sub-macroblock can be independently partitioned into 8*8, 8*4, 4*8, and 4*4 blocks. So, altogether there can be seven different block-sizes: 16*16, 16*8, 8*16, 8*8, 8*4, 4*8, and 4*4. For these block-sizes, each 16*16 MB contains 1, 2, 2, 4, 8, 8, and 16 blocks respectively.
In the H.264/MPEG-4 AVC reference software, a Fast Full Search (FFS) algorithm is used for the ME. The SADs (Sum of Absolute Differences) of 4*4 blocks are first calculated and the SADs of the other six block-modes are calculated by summing up the SADs of the corresponding 4*4 blocks. Although the SADs in the calculation of the 4*4 block-mode are re-used, for all seven block-sizes, the SAD calculation load will be larger than that using a full-search ME for a 16*16 MB. For example, if a search-window size is 31*31 pixels and the Unrestricted Motion Vector (UMV) mode is enabled, the number of search points using the full-search ME is 31*31=961. Accordingly, the required SAD computation is larger than that for a 16*16 MB with 961 search points, which requires a lot of computations.
Recently some fast variable block-size ME algorithms have been proposed. For example, a fast search algorithm is applied to the seven block-sizes independently, as disclosed by Ma et al. in an article entitled "An Improved Adaptive Rood Pattern Search For Fast Block-matching Motion Estimation in JVT/H.26L". A merge procedure is also proposed, as disclosed by Tu et al. in "Fast Variable-size Block Motion Estimation Using Merging Procedure With an Adaptive Threshold", which determines the MVs of larger block-sizes from the MVs of smaller block-sizes, with the threshold for the merge criteria related to the quantization parameter. Kucukgoz et al. in their article entitled "Early-stop and Motion Vector Re-using for MPEG-2 to H.264 Transcoding" apply a bottom-up merge scheme and an early-stop strategy for the variable block-size ME in MPEG-2 to H.264 transcoding. Furthermore, in "Fast Integer Pixel Motion Estimation" disclosed by Li et al., a merge and split process for the ME is proposed. The disclosure, however, fails to describe the detailed process.

System and method for fast variable-size motion estimation

Industrial Technology Research Institute


A side-handle for a hand-held power tool includes a gripping element and a fastener for fastening the side handle to the hand-held power tool. The gripping element and the fastening means can be pivoted with respect to each other around a rotational axis. This rotational axis runs perpendicular to a longitudinal axis of the gripping element and runs through an end area of the gripping element facing away from the fastener.

Hand-held power tools transmit vibrations to a side handle. Damping elements in the side handle serve to reduce the amplitude of the vibrations on a gripping surface. U.S. Pat. No. 5,157,807 A describes such a handle.
The vibration-damping side handle is a compromise between the ability to transmit forces from the user to the hand-held power tool and the ability to reduce vibrations caused by the hand-held power tool on the gripping surface. The transmission of forces calls for stiff, unyielding elements. Damping, especially of low-frequency vibrations, requires soft, yielding elements.
As an alternative, the inertia of the side handle can be increased by raising its mass in order to improve the damping. This, however, increases the weight of the hand-held power tool.


A Superconducting Quantum Interference Device (SQUID) is disclosed comprising a pair of resistively shunted Josephson junctions connected in parallel within a superconducting loop and biased by an external direct current (dc) source. The SQUID comprises a semiconductor substrate and at least one superconducting layer. The metal layer(s) are separated by or covered with a semiconductor material layer having the properties of a conductor at room temperature and the properties of an insulator at operating temperatures (generally less than 100 Kelvins). The properties of the semiconductor material layer greatly reduces the risk of electrostatic discharge that can damage the device during normal handling of the device at room temperature, while still providing the insulating properties desired to allow normal functioning of the device at its operating temperature. A method of manufacturing the SQUID device is also disclosed.

Thin film devices typically comprise a multiplicity of metal wiring layers separated by insulating, or dielectric, material layers to provide electrical isolation. If the dielectric used to electrically isolate the wiring layers of a thin film circuit is a perfect insulator, normal handling of the chips cut from fabricated wafers can lead to the accumulation of electrostatic charge and the formation of very large potential differences between the thin-film layers of the device. An electrostatic discharge (ESD) occurs if the potential difference becomes too large, which can damage or destroy the circuit. In order to minimize device failure owing to electrostatic discharge, special ESD-safe workstations and tools are required, and all personnel handling the circuits must wear grounded wrist straps and heel straps. Anti-static lotions and smocks also are commonly used when handling sensitive circuits.
Thus, it would be desirable to provide a device which minimizes the potential difference between adjacent metal wiring layers during normal handling, but which also provides the desired isolation between such layers during operation, when such isolation is functionally required. Specifically, for superconducting devices it would be desirable to provide a transition layer which provides conductance between adjacent metal layers during handling at room temperature, when the potential for ESD is greatest, but which acts as an insulator between the metal layers during operation, at temperatures below about 100 Kelvins (K).
Devices incorporating layers of material capable of undergoing an insulator to metal transition are known. For example, in U.S. Pat. No. 6,365,913 to Misewich et al., a Field effect transistor semiconductor switch is disclosed in which the channel is made from materials having an electrical conductivity which can undergo an insulator-metal transition (i.e., Mott transition) upon application of an electric field. Likewise, U.S. Pat. No. 5,721,197 to Downar et al. discloses a microelectronic thin-film device having a thin superconducting layer in contact with a thin quasi-insulating conversion layer. The critical current of the superconducting layer is controlled by application of a voltage to the conversion layer by means of a gate electrode, causing the conversion layer to undergo an insulator-metal transition. Both references require the application of a voltage or electric field in order to change the conductivity of the transition material.
Thus, there remains a need for a device that allows for conductance between metal layers during normal handling at room temperatures, thus minimizing the potential for destructive ESD, but which provides the desired electrical isolation between metal layers during normal operation at the low operating temperatures associated with superconducting devices.

Charge dissipative dielectric for cryogenic devices


An anti-vehicle-thief apparatus registers specific ID codes of a plurality of keys, and determines validity of a key, for example, in accordance with an operation of the key 1 including a transponder having one of the registered specific ID codes. The anti-vehicle-thief apparatus registers a code specific to the key and confirms an operation in which an ignition switch is turned on and off five times by using the key, where this operation is for changing the ID codes specific to the plurality of keys registered in EEPROMs. After the confirmation of the operation, ID codes specific to a plurality of new keys are successively registered, thereby preventing a third person from using the old keys, as well as making registration of the ID codes specific to the new keys easily.

The present invention relates to an anti-vehicle-thief apparatus and a code setting method of the apparatus.
Recently, burglaries of vehicles occur more frequently in many countries. In order to prevent burglaries, many types of burglar alarms and the like have been suggested, e.g., a key-less entry system and the like as a conventional burglar alarm. In a suggested key-less entry system, after a reset switch in the receiving side is powered on, an identification code sent from a transmitter is stored, as disclosed in Japanese Utility Model Application Laid-Open No. 2-105469. Further, an anti-vehicle-thief system for vehicles, so called an immobilizer unit, has been developed. In this system, if a burglar enters a vehicle and turns on the ignition switch, the system does not allow the engine of the vehicle to start.
However, there is a problem in the aforesaid conventional burglar alarms in which, when a burglar enters a vehicle and the burglar alarm sounds the alarm, since the alarm sound is frequently heard recently, passers-by do not give much attention to the alarm sound.
Further, in the key-less entry system, it is possible to prevent a burglar from entering a vehicle by a door. However, if the burglar breaks a window and enter the vehicle, it is not very difficult to turn on the ignition switch.

Anti-vehicle-thief apparatus and code setting method of the apparatus


Methods and systems for imaging a biological sample are disclosed, and include: (a) staining the sample with a first stain that includes eosin and at least one additional stain; (b) directing excitation light to the sample to cause each of the stains to emit fluorescence; and (c) recording images of the fluorescence emitted from the stains in the sample, where the amount of eosin in the sample is sufficiently dilute to cause the sample to have an average optical density of less than 0.10 at green wavelengths.

Analysis of cells and tissue samples can involve preparing the sample with stains, including histological stains or immunofluorescent (IF) probes, and then determining the amount of stain present at various locations in the sample.
Automated image analysis of such samples can include finding areas of interest within tissue samples, locating certain types of cells, and/or locating sub-cellular compartments within cells of interest, and determining the amount of stain in various regions, cells and/or sub-cellular compartments. Little or no user intervention is required in many cases.
IF probes have molecular specificity so they bind only to regions of a sample where a target compound is present, and the amount of probe binding is approximately proportional to the amount of the target compound present. Because multiple IF probes can be applied to a single sample, it is possible to measure several analytes in a given cell or tissue section.
A common way to prepare cell or tissue samples for visual review or automated image analysis is via hematoxylin and eosin (H&E) staining protocols that produce vivid color contrast when the sample is viewed in a transmitted-light microscope.

Cambridge Research & Instrumentation, Inc.


In an image projection system, there are at least two light illumination units producing illumination light beams of respective first and second primary colors. A first beamsplitter is disposed to split at least a portion of the first illumination light beam into sub-beams, one of which is directed to a first image-forming panel. The other sub-beam is combined with at least some of the second illumination light beam to form a light beam of mixed light that illuminates the image-forming panel. In some embodiments, the first beamsplitter is a polarizing beamsplitter.

Illumination systems may be found in many different applications, including image projection display systems, backlights for liquid crystal displays and the like. Projection systems usually use a source of light, illumination optics to pass the light to one or more image-forming devices, projection optics to project the image(s) from the image-forming device(s) and a projection screen on which the image is displayed. The image-forming device(s) are controlled by an electronically conditioned and processed video signal.
White light sources, such as high-pressure mercury lamps, have been, and still are, the predominant light sources used in projection display systems. In a three-panel image-projection system, the white light beam is split into three primary color channels, red, green and blue, and is directed to respective image-forming device panels that produce the image for each color. The resulting primary-colored image beams are combined into a full color image beam that is projected for display. Some other projection systems use a single imager panel, and so rotating color wheels, or some other type of time-sequential color filter, is used to filter the white light so that light at one primary color is incident on the image-display device at any one time. The light incident at the panel changes color sequentially to form colored images synchronously with the incident light. The viewer's eye integrates the sequentially colored images to perceive a full color image.
More recently, light emitting diodes (LEDs) have been considered as an alternative to white light sources. For a three panel system, an array of red LEDs is used to illuminate the red channel, an array of green LEDs is used for the green channel and an array of blue LEDs is used for the blue channel. Some advantages of using LED light sources include longer lifetime, higher efficiency and superior thermal characteristics.
LED-based illumination systems display a color gamut that is different from that recommended by the Society of Motion Picture and Television Engineers in Recommended Practices 145-1999, "C Color Monitor Colorimetry" (referred to hereafter as SMPTS 145-1999). Also, in order to achieve an acceptable white color, LED-based illumination sources are often run in a mode that fails to realize the full intensity available from all LEDs, so the overall brightness of the image is reduced.