By Comparison Or Difference Circuit Patents (Class 324/672)
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Patent number: 8041083Abstract: A fingerprint sensing circuit for detecting a fingerprint of a user, including a signal source, at least a sensing unit, a resistor, an electrode, and a detecting circuit. The signal source provides a reference signal. The electrode is coupled to a reference level. The sensing unit generates a sensed value according to the electrode and the fingerprint of the user. The resistor is coupled between the signal source and the output node. The detecting circuit is coupled to the output node. The resistor, the sensing unit, and the electrode constitute a filter circuit to the signal source. At least a first signal is generated to the output node according to the reference signal and the sensed value, and the detecting circuit detects the first signal to generate a corresponding detected result indicative of the fingerprint.Type: GrantFiled: June 20, 2008Date of Patent: October 18, 2011Assignee: MStar Semiconductor, Inc.Inventors: Hung-Chuan Pai, Shou-Fang Chen, Chao-Tung Yang
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Patent number: 8028990Abstract: A paper thickness detecting apparatus includes a first sensor and a second sensor in which the electrostatic capacitance changes when a piece of paper such as a bank note or a piece of copying paper is inserted, and a thickness detecting unit for detecting the thickness of the piece of paper from the signals obtained from the respective first sensor and the second sensor, in order to provide a paper thickness detecting apparatus that can reliably detect a foreign object adhered to the paper.Type: GrantFiled: January 20, 2010Date of Patent: October 4, 2011Assignee: Fujitsu LimitedInventor: Akinori Miyamoto
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Patent number: 7956623Abstract: The present invention provides a container filling machine comprising a sensing device for detecting the integrity of discrete articles for personal treatment to be packaged in a container. The sensing device comprises a pair of capacitor plates positioned in a substantially opposing relationship for creating therebetween an electric field, a track for guiding the discrete articles for personal treatment through said electric field and a processing unit. The processing unit is in communication with the pair of capacitor plates, and is operative for detecting a change in capacitance as a discrete article passes through the electric field in order to determine the integrity of the discrete article on the basis of the change in capacitance and a characteristic capacitance change signature. The container filling machine further comprises a transportation device, a rejection device, a counting device and a plurality of path blocking devices.Type: GrantFiled: February 16, 2007Date of Patent: June 7, 2011Assignee: Countlab, IncInventors: Loris Bassani, Gueorgui Poklitar
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Patent number: 7924029Abstract: Methods and apparatus are provided for measuring a ratio of capacitances.Type: GrantFiled: December 22, 2006Date of Patent: April 12, 2011Assignee: Synaptics IncorporatedInventors: Joseph Kurth Reynolds, Kirk Hargreaves
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Patent number: 7834645Abstract: A variable capacitance circuit includes a capacitance changing structure constructed by connecting a first construction unit, a second construction unit, a third construction unit, and a fourth construction unit, which each include a first electric element that hinders transmission of a direct current (DC) signal and has a capacitance that changes in accordance with the magnitude of an absolute value of an applied voltage, in the mentioned order in a ring. A voltage measuring apparatus measures the voltage of a measured object and includes a detection electrode capable of being disposed facing the measured object and the variable capacitance circuit described above. A power measuring apparatus includes a current measuring apparatus that measures current flowing in a measured object and the voltage measuring apparatus that measures the voltage of the measured object.Type: GrantFiled: December 15, 2006Date of Patent: November 16, 2010Assignee: Hioki Denki Kabushiki KaishaInventor: Koichi Yanagisawa
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Publication number: 20100231239Abstract: A capaciatance detector is provided, which outputs an electric signal dependent on the capacitance present on an object to be measured. The capaciatance detector includes a measurement terminal to be disposed in contact with or in proximity to the object being measured; an impedance conversion circuit connected to the measurement terminal to form a resonant circuit; a reference phase oscillator for supplying a reference phase signal at a constant frequency to the resonant circuit; phase comparison means for outputting, as a capacitance detected signal, a phase difference signal indicative of the phase difference between a resonant signal, which is extracted from the resonant circuit in response to the reference phase signal being applied to the resonant circuit, and the reference phase signal; and resonance frequency regulation means for regulating the resonance frequency of the resonant circuit based on the phase difference signal.Type: ApplicationFiled: October 18, 2007Publication date: September 16, 2010Inventors: Kiyoshi Tateishi, Yuji Tawaragi
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Patent number: 7795882Abstract: An electrical characteristic in an operator-sensing circuit having a microcontroller that commands a charge sensor to send a sensor charge signal to a capacitive sensing element. The charge sensor outputs a corresponding raw data signal to the microcontroller that in turn sends a signal that disables the motor of a unit power equipment upon the absence of an operator's hand on a hand-gripping surface of the equipment. Capacitive means for operating within a predetermined charge range that includes preselected values that designate hands-off and hands-on conditions on the hand-gripping surface. The capacitor charge range is effective to distinguish between the presence of an operator's hand and foreign material on the gripping surface for avoiding a false hands-on-signal.Type: GrantFiled: August 15, 2006Date of Patent: September 14, 2010Assignee: Gustav Magenwirth GmbH & Co. KGInventors: Markus Kirchner, Markus Neidert, Ralph Sauter, Bernhard Mittmann
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Patent number: 7768272Abstract: A capacitance detecting apparatus includes: a first on/off switch; a first reference capacitor; a second on/off switch; a third on/off switch; a first sensor electrode; a fourth on/off switch; a second reference capacitance; a fifth on/off switch; a sixth on/off switch; a second sensor electrode; a comparator; switch controlling means for alternately repeating a second switch operation and a third switch operation following a first switch operation; counting means for counting a number of times for repeating the second switch operation; and judging means for judging changes in capacitances related to the first and second sensor electrodes, based upon the number of times for repeating the second switch operation counted by the counting means before a level of voltage at the first input terminal and a level of voltage at the second input terminal are reversed.Type: GrantFiled: September 7, 2007Date of Patent: August 3, 2010Assignee: Aisin Seiki Kabushiki KaishaInventors: Manabu Kato, Eiji Fujioka
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Publication number: 20100117662Abstract: In a method or system for processing a measurement signal to detect a property of a toner mark, the toner mark is generated with aid of an image generation device. The toner mark is detected with aid of a measurement unit in that sample values determined by the measurement unit at sample points in time are output as the measurement signal for detecting the property of the toner mark. A function is determined to describe at least one part of a signal curve of the measurement signal on a basis of at least one part of the output sample values. At least one extreme value of the function is determined.Type: ApplicationFiled: January 11, 2008Publication date: May 13, 2010Inventors: Bernhard Hochwind, Markus Jeschonek
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Patent number: 7652486Abstract: A capacitance detection circuit that compensates for the fluctuation of a reference voltage with a simple structure. A C-V circuit for a sensor element generates a detection signal by amplifying a capacitance change value of the sensor element by a predetermined gain based on a reference voltage. A voltage compensation circuit, which is connected to the C-V circuit and supplies a reference voltage to the C-V circuit, reduces the gain relative to a deviation amount when the reference voltage fluctuates by a predetermined deviation amount.Type: GrantFiled: January 17, 2008Date of Patent: January 26, 2010Assignee: Freescale Semiconductor, Inc.Inventor: Eiji Shikata
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Publication number: 20100007360Abstract: The invention provides a fluid sensor device (1; 1?; 1?; 1?) for detecting a dielectricity constant of a fluid (30) present in a fluid line (20), comprising a housing (5; 5?; 5?; 5?); a plate capacitor device provided on the inside of the housing (5; 5?; 5?; 5?), the plate capacitor device comprising a first and a second capacitor plate (8a, 8b; 8a?, 8b?; 8a?, 8b?; 8a?, 8b?); wherein the housing (5; 5?; 5?; 5?) on the surface thereof has an arched attachment region for attaching the fluid line (20); and wherein the first and second capacitor plates (8a, 8b; 8a?, 8b?; 8a?, 8b?; 8a?, 8b?) are disposed next to the attachment region such that a fluid (30) present in the fluid line (20) attached in the attachment region is provided at least partially between the first and second capacitor plates (8a, 8b; 8a?, 8b?; 8a?, 8b?; 8a?, 8b?).Type: ApplicationFiled: May 26, 2008Publication date: January 14, 2010Inventors: Udo Kaess, Monlka Scherer, Gustav Klett, Markus Niemann
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Patent number: 7619421Abstract: A method for detecting capacitor variation in a device comprises operating an oscillator in the device, the oscillator being an Inductive-Capacitive (LC) oscillator and including an inductor of known value and a capacitor under test, comparing an output of the oscillator to a reference output, and evaluating variation for a plurality of capacitors in the device based on the comparing.Type: GrantFiled: August 31, 2006Date of Patent: November 17, 2009Assignee: Microtune (Texas), L.P.Inventors: Jan-Michael Stevenson, Timothy M. Magnusen
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Patent number: 7521940Abstract: A capacitive sensor is provided. The capacitive sensor includes a sensor/heat pad for outputting a sensing signal, a first diode coupled to a first node of the sensor/heat pad, a second diode coupled to a second node of the sensor/heat pad, a first transistor coupled to the first diode and a second transistor coupled to the second diode. During a sensing mode, the first and second transistors are opened and a reverse-biased signal is applied to the first diode and the second diode so that the sensor/heat pad is isolated from the first and second transistors.Type: GrantFiled: January 26, 2007Date of Patent: April 21, 2009Assignee: TK Holdings Inc.Inventors: Stu Koch, Phil Maguire
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Patent number: 7504833Abstract: Disclosed is method for compensating for variation in the capacitance between multiple capacitive sensors. Prior to sensing operations, baseline capacitance values can be acquired for all sensors. A correction factor can be calculated based on such baseline values. During sensing operations (run-time), variations in capacitance from baseline values can be modified by appropriate correction factors. Sensitivity between sensors can thus be made more uniform.Type: GrantFiled: March 31, 2006Date of Patent: March 17, 2009Assignee: Cypress Semiconductor CorporationInventor: Dennis Seguine
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Patent number: 7368922Abstract: The invention relates to a method and a device for determining the parameters of a fluctuating flow of a fluid in a pipe, wherein at least three electrodes that are placed at a distance from one another in the direction of flow are provided in the periphery of the flow, wherein alternating voltage signals are fed to a first upstream transmission electrode arrangement and to a second downstream transmission electrode arrangement and the receiving signals generated by the displacement current are detected in a receiving electrode arrangement located between the transmission electrodes and subjected to a time-discrete cross-correlation. The throughput times of the fluctuations detected by the electrodes are determined on the basis of the results.Type: GrantFiled: February 10, 2005Date of Patent: May 6, 2008Assignees: Technische Universitat Graz, Forschungsholding Tu Graz GmbHInventors: Hubert Zangl, Anton Fuchs
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Patent number: 7288945Abstract: Methods and systems are described for efficiently detecting an object. The system includes at least one electrode for measuring a displacement current. The at least one electrode is coupled to a floating ground configuration provided by an op-amp, where the inverting node of the op-amp is coupled to electrode and the non-inverting node is coupled to a signal generator. The system may include a single capacitance sensor for detecting an object. Systems may include a plurality of capacitance sensors in an array configuration for detecting an object.Type: GrantFiled: August 11, 2005Date of Patent: October 30, 2007Assignee: Southwest Research InstituteInventors: Robert E. Martinez, Stephen A. Cerwin, Todd H. Goyen
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Patent number: 7282927Abstract: A method and apparatus for measurement of capacitance by use of an adaptive input-cell circuitry, part of a configurable electronic controller, or generally by a computer controlled adaptive input-cell. The input-cell comprises a comparator, two transistor switches and resistor networks, respectively connected to the comparator and two switches. The input-cell receives control signals to the transistor switches and a synchronization waveform input from the configurable electronic controller or computer. The input-cell measures the capacitance connected at its input or alternatively the self-capacitance of an open conductor. The input-cell converts the input signal parameters into time-based signals, which cumulative count are related to the value of the measured capacitance.Type: GrantFiled: June 21, 2006Date of Patent: October 16, 2007Assignee: Eastman Kodak CompanyInventor: Vitaly Burkatovsky
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Patent number: 7279908Abstract: A differential signaling system is provided. The differential signaling system comprises one or more cable pairs for carrying signals, one or more differential drivers for providing signals to the one or more cable pairs, and one or more differential receivers, the one or more differential receivers being coupled to the one or more differential drivers via the one or more cable pairs. The differential signaling system further comprises one or more test devices for testing the differential signaling system, and at least one switch coupled to at least one of the one or more cable pairs and to at least one of the one or more test devices, the switch being adapted to dynamically switch the at least one of the one or more test devices into a differential interface of the differential signaling system.Type: GrantFiled: December 6, 2005Date of Patent: October 9, 2007Assignee: Honeywell International Inc.Inventor: Christopher L. Blake
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Patent number: 7256588Abstract: A method for non-contact measurement of a displacement between a surface and a capacitive sensor comprised of at least two superimposed conductive plates electrically insulated one from the other and a sensor circuit coupled to the plates including: positioning the capacitive sensor proximate to the surface such that the displacement is a distance of a gap between the surface and one of the plates; applying a high frequency signal to the plates; applying the high frequency signal and a sensor plate to control a voltage gain of an amplifier in the circuit, where the capacitance on the sensor is indicative of the displacement between the sensor and surface; differentiating an output of the amplifier and the high frequency signal, and determining a value of the displacement based on the difference between the output of the amplifier and the high frequency signal.Type: GrantFiled: April 16, 2004Date of Patent: August 14, 2007Assignee: General Electric CompanyInventors: Jack E. Howard, Oliver H. Lieder, Brian Burket Bowlds, Paul Austin Lindsay
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Patent number: 7235985Abstract: A method and a device (1) for detecting signal amplitudes by removing any DC component from the signal and then shifting the signal by a shift amount so as to produce a shifted signal having a first signal level equal to a reference level (Vref). The shift amount provides an indication of the amplitude of the signal. To this end, the device (1) includes a decoupling circuit (2), a shift circuit (3) and an output terminal (4). Optionally the device further includes a differential amplifier (5) coupled to receive the reference level (Vref) and an indication of the power of the shifted signal, and a signal power determination circuit (6) coupled between the shift circuit (3) and the differential amplifier (5).Type: GrantFiled: September 22, 2003Date of Patent: June 26, 2007Assignee: NXP B.V.Inventor: Roeland John Heijna
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Patent number: 7129693Abstract: A voltage sensor is described that consists of a plurality of identical series-connected sections, where each section is comprised of an arrangement of impedance elements. The sensor is optimized to provide an output ratio that is substantially immune to changes in voltage, temperature variations or aging. The voltage sensor can be scaled to various voltage levels by varying the number of series-connected sections.Type: GrantFiled: July 17, 2005Date of Patent: October 31, 2006Assignee: FieldMetrics, Inc.Inventors: Christopher Paul Yakymyshyn, Michael Allen Brubaker, Pamela Jane Yakymyshyn
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Patent number: 6998856Abstract: A computer system (10) includes a keyboard (11), a first pair of position-sensing electrodes (18.1 and 18.2), a second pair of position-sensing electrodes (20.1 and 20.2), a signal injection electrode (22) and an oscillator (27). The oscillator injects a signal via the electrode (22) and the operators left hand L, creating a field around the operator's right hand R. The position electrodes are arranged underneath the keyboard and sense the strenght of the field enabling the position of the operator's right hand R in an X-Y plane above the keyboard to be determined. Each position-sensing electrode is coupled to a difference amplifier (28 and 30) via a pair of buffer amplifiers (40.1, 40.2, 30.1, 30.2). The amplification factor of the buffer amplifiers can be varied so as to scale the field strength values sensed by the electrodes, thereby permitting the output of the difference amplifier to be varied so as to adjust the sensivity of the system to different positions of the operator's hand R.Type: GrantFiled: June 28, 2002Date of Patent: February 14, 2006Assignee: EthertouchInventor: Hans Rudolf Sterling
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Patent number: 6906531Abstract: An adaptive reference voltage method and system analyzes a received bus signal to evaluate voltage swing characteristics and adjusts the reference voltage for reading the signal to a level that compensates for variations in margins between high and low signal switching values such as are introduced by noise. A bus input signal analyzer circuit incorporated in an integrated circuit analyzes the bus signal received at the integrated circuit to adjust the reference voltage used by the integrated circuit. In one embodiment, the bus input signal analyzer circuit applies a feedback loop to adapt the reference voltage by setting high and low input values to a reference voltage generation circuit with the reference voltage centered between the high and low values, such as results from a resistor divider network.Type: GrantFiled: October 11, 2002Date of Patent: June 14, 2005Assignee: Dell Products L.P.Inventor: James B. Mobley
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Patent number: 6882164Abstract: A capacitance sensor usable as a fingerprint sensor is provided in which a timing controller (16) provides such a switching control as to first cause a switch (SA) in a sensor cell (100-k) to turn on to set the potential at a sense electrode to a reference potential and then a switch SB to turn on after the switch (SA) is turned off, whereby charge is stored from the sensor cell (100-k) into a reference capacitance Cf1 of a sensing circuit (13-k), the sensitivity of sensing the capacitance is raised by increasing the number of times the charge storage is repeated and only signal components are extracted by reducing noise components by averaging.Type: GrantFiled: July 4, 2002Date of Patent: April 19, 2005Assignee: Sony CorporationInventors: Motoyasu Yano, Masaki Yoshioka, Keiichi Shinozaki
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Patent number: 6864691Abstract: A circuit arrangement for detecting the capacitance or capacitance change of a capacitive circuit element or component, in which there is a capacitive noise voltage compensation element, which corresponds to the sensor capacitor, represented as a noise voltage compensation capacitor, and a noise voltage compensation electrode of the noise voltage compensation capacitor, which corresponds to the first electrode of the sensor capacitor, is connected to the second electrode of a storage capacitor. The noise voltage compensation capacitor can be influenced in the same way as the sensor capacitor by the LF noise voltage. In this way, the adulteration of the measurement result by LF noise voltages which otherwise occurs no longer takes place.Type: GrantFiled: December 13, 2002Date of Patent: March 8, 2005Assignee: i f m electronic GmbHInventors: Jaromir Palata, Joerg Schulz
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Patent number: 6822431Abstract: Disclosed is an intrinsically safe sensor signal processing circuit, permitting lower cost installation and eliminating potential hazard. In the combination of a sensor which measures physical value as process variables in hazardous environment and a safety barrier which is mounted in non-hazardous environment, an intrinsically safe sensor signal processing circuit features the safety barrier for case of mounting, wherein current limiting resistances are connected in series with the sensor and these resistances are also connected to either an output or an inverting input of OP Amps that are considered as a driver or a feeder of the sensor signal. The safety barrier can adopt blocking capacitors instead of said current limiting resistors.Type: GrantFiled: July 16, 2003Date of Patent: November 23, 2004Assignee: Yamatake CorporationInventors: Takashi Masuda, Yasuhide Yoshikawa
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Patent number: 6777958Abstract: A method for detecting a change in capacitance of a capacitive sensing element having a nominal capacitance value is disclosed. In an exemplary embodiment, the method includes coupling the sensing element to a first oscillator, the first oscillator generating a first frequency dependent upon the capacitance value of the sensing element. The first frequency is compared to a reference frequency generated by a second oscillator. The change in capacitance from the nominal capacitance value is detected if the first frequency differs from said reference frequency by a determined frequency value.Type: GrantFiled: May 10, 2002Date of Patent: August 17, 2004Assignees: Delphi Technologies, Inc., Hughes Aircraft CompanyInventors: Ronald Helmut Haag, John Pasiecznik, Jr.
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Publication number: 20040113635Abstract: Disclosed is an intrinsically safe sensor signal processing circuit, permitting lower cost installation and eliminating potential hazard. In the combination of a sensor which measures physical value as process variables in hazardous environment and a safety barrier which is mounted in non-hazardous environment, an intrinsically safe sensor signal processing circuit features said safety barrier for case of mounting, wherein current limiting resistances are connected in series with a sensor and these resistances are also connected to either an output or an inverting input of OP Amps that are considered as a driver or a feeder of a sensor signal. And/or said safety barrier can adopt blocking capacitors instead of said current limiting resistors.Type: ApplicationFiled: July 16, 2003Publication date: June 17, 2004Inventors: Takashi Masuda, Yasuhide Yoshikawa
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Publication number: 20040070409Abstract: An adaptive reference voltage method and system analyzes a received bus signal to evaluate voltage swing characteristics and adjusts the reference voltage for reading the signal to a level that compensates for variations in margins between high and low signal switching values such as are introduced by noise. A bus input signal analyzer circuit incorporated in an integrated circuit analyzes the bus signal received at the integrated circuit to adjust the reference voltage used by the integrated circuit. In one embodiment, the bus input signal analyzer circuit applies a feedback loop to adapt the reference voltage by setting high and low input values to a reference voltage generation circuit with the reference voltage centered between the high and low values, such as results from a resistor divider network.Type: ApplicationFiled: October 11, 2002Publication date: April 15, 2004Inventor: James B. Mobley
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Patent number: 6646453Abstract: A method for capacitively measuring the thickness of multi-layer films (10), the layers (32, 34) the dielectric constants of which differ at least at a particular temperature, wherein, in addition to the capacitive measurement, at least one further thickness measurement is carried out under different conditions, and wherein the thicknesses (d1, d2) of the individual layers is determined by comparing the measurement results and by means of the different dielectric constants.Type: GrantFiled: November 6, 2001Date of Patent: November 11, 2003Assignee: Plast-Control Gerätebau GmbHInventors: Frank Müller, Stefan Konermann, Norbert Sappelt
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Patent number: 6639414Abstract: Disclosed is a single-stage, switched capacitor circuit for measuring changes in a variable by measuring changes in a capacitor gap. The change in the capacitor gap corresponds directly to a change in a measurable variable, such as pressure and acceleration, and thus a change in voltage. The circuit includes at least one reference capacitor, a sensor capacitor, a plurality of switches responsive to a timing device, and a device for generating substantially constant reference voltages. The sensor circuit does not result in a DC offset value, but results in the AC component of the voltage being directly proportional to the change in the variable through a substantially constant voltage is supplied to a node near the sensor capacitance. The circuit may be trimmed using a digital to analog converter and/or capacitors coupled in parallel.Type: GrantFiled: December 19, 2001Date of Patent: October 28, 2003Assignee: Institute of MicroelectronicsInventor: Wee Liang Lien
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Patent number: 6566892Abstract: A portable fuel analyzer includes a sensor, a processor and a display. The portable analyzer receives a fuel sample and the display identifies whether the vehicle fuel is tainted. The portable fuel analyzer is linked to an evaluation unit to determine a frequency measurement based upon signals from the sensor in the portable fuel analyzer. The evaluation unit provides a method of comparing the frequency from the vehicle fuel sensor with the frequency from the portable fuel analyzer. If the green LED is illuminated and the portable fuel analyzer indicates a different frequency than the vehicle fuel sensor, the vehicle fuel sensor is defective and should be replaced; If the green LED is illuminated and the portable fuel analyzer indicates the same frequency as the vehicle fuel sensor, a vehicle component other than the vehicle sensor is faulty; and, if the red LED is illuminated, the mixed fuel sample is tainted and a determination about the vehicle fuel sensor cannot be determined.Type: GrantFiled: May 21, 2001Date of Patent: May 20, 2003Assignee: Siemens VDO Automotive CorporationInventors: Rick Schaefer, Isabelle Desmier
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Patent number: 6545488Abstract: To enable a fluid state of a fluid substance flowing through a path in a piping, for example a liquid state or a froth state of beer, to be surely and easily judged while keeping a sanitary condition, allowing a take out to be surely and easily performed, a piping fluid decision device is constituted with an electrostatic capacity sensor (15) disposed outside of a piping (1) adapted for a fluid substance to flow through a path therein, for detecting a variation of electrostatic capacity of the path in the piping (1), reference value storage means for storing in advance a reference variation of electrostatic capacity of the path to provide for a decision on a fluid state of the fluid substance flowing through the path in the piping, and fluid decision means for comparing the detected variation of electrostatic capacity and the stored variation of electrostatic capacity to make the decision on the fluid state of the fluid substance flowing through the path.Type: GrantFiled: May 30, 2001Date of Patent: April 8, 2003Assignee: Unirec Co., Ltd.Inventors: Junichi Yamagishi, Eikou Yo
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Patent number: 6538458Abstract: There is provided a small, high-performance electrostatic capacitance probe device and a displacement measuring circuit using the probe device. The electrostatic capacitance probe device is formed from a processed, stacked substrate with a silicon substrate/insulator/silicon substrate structure. A support substrate (1) is formed through a process of etching the first silicon substrate to remove undesired portions. A probe (2) is formed by etching the second silicon substrate and provided with a proximal electrode portion (2b) secured on the support substrate (1) by means of the insulator (11) and a beam portion (2a) separated from the support substrate (1) by removing the insulator (11) from beneath the beam portion (2a). A pair of detecting electrodes (3, 4) is formed by etching the second silicon substrate, secured on the support substrate (1) by the insulator (1) and located to sandwich a portion of the beam portion (2a) close to the proximal electrode portion (2b).Type: GrantFiled: July 26, 2001Date of Patent: March 25, 2003Assignee: Mitutoyo CorporationInventors: Michihiko Togashi, Osamu Kawatoko
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Patent number: 6513367Abstract: A method for generating indicators relating to the condition of lubricating oil in an internal combustion engine. A set of variables relating to operation of the internal combustion engine serve as proxy variables for brake mean effective pressure developed by the internal combustion engine. Operation of an engine is monitored to develop values for the proxy variables. Soot being added to the lubricating oil from the developed values and accumulated to provide an estimate of total soot in the lubricating oil. Lubricating oil temperature is periodically monitored and a history of the lubricating oil temperature measurements is kept to allow generation therefrom of an estimate of shear of the lubricating oil. Accumulated estimate of soot is kept as a distance remaining until the lubricating oil becomes unsuitable for continued use in the internal combustion engine. Similarly, estimated shear is expressed as a distance until the lubricating oil is to be replaced.Type: GrantFiled: February 22, 2001Date of Patent: February 4, 2003Assignee: International Truck Intellectual Property Company, L.L.C.Inventors: Frank Bondarowicz, Kevin R. Calstrom, Gerald L. Larson
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Patent number: 6501284Abstract: Within a capacitive fingerprint detection device, finger detection is provided by a capacitive grid overlying the fingerprint sensor electrodes to measure the absolute capacitance of the finger placed on the sensor surface. The capacitive measurement is converted to a representative frequency, which is then compared to a reference frequency or frequency range to determine whether the measured capacitance matches the expected bio-characteristics of living skin tissue. The finger detection thus provides anti-spoofing protection for the fingerprint detection device.Type: GrantFiled: August 28, 2000Date of Patent: December 31, 2002Assignee: STMicroelectronics, Inc.Inventor: Giovanni Gozzini
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Publication number: 20020118025Abstract: To enable a fluid state of a fluid substance flowing through a path in a piping, for example a liquid state or a froth state of beer, to be surely and easily judged while keeping a sanitary condition, allowing a take out to be surely and easily performed, a piping fluid decision device is constituted with an electrostatic capacity sensor (15) disposed outside of a piping (1) adapted for a fluid substance to flow through a path therein, for detecting a variation of electrostatic capacity of the path in the piping (1), reference value storage means for storing in advance a reference variation of electrostatic capacity of the path to provide for a decision on a fluid state of the fluid substance flowing through the path in the piping, and fluid decision means for comparing the detected variation of electrostatic capacity and the stored variation of electrostatic capacity to make the decision on the fluid state of the fluid substance flowing through the path.Type: ApplicationFiled: May 30, 2001Publication date: August 29, 2002Inventors: Junichi Yamagishi, Eikou Yo
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Publication number: 20020075015Abstract: A battery voltage measurement device includes: a plurality of first switching sections, wherein each pair of adjacent first switching sections sequentially selects two output terminals of each of a plurality of battery blocks included in a battery pack so that each of the selected output terminals are connected to one of a pair of conductor wires; a voltage detection section for detecting a battery voltage of each of the plurality of battery blocks via the pair of conductor wires; and second switch sections each being provided on a respective one of the pair of conductor lines and being serially connected to each group of the plurality of first switch sections connected in parallel to one of the pair of conductor lines.Type: ApplicationFiled: November 2, 2001Publication date: June 20, 2002Inventors: Naohisa Morimoto, Ichiro Maki, Hirofumi Yudahira
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Patent number: 6407556Abstract: A sensor for indicating changes in the physical presence of persons or objects and including at least two electrically conductive sheets of material that are spaced mutually apart on an electrically non-conductive carrier sheet or the like. A sensing circuit is also provided for sensing changes in the capacitance between the electrically conductive sheets.Type: GrantFiled: November 3, 1999Date of Patent: June 18, 2002Inventor: Jan Rudeke
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Patent number: 6072319Abstract: The disclosure relates to a device for measuring properties of a textile product in a measuring gap in which the textile product is inserted. On each of its surfaces the measuring gap has an electrode of a measuring capacitor, between which the product is inserted, an electrode of a compensation capacitor and a conductor. Disturbing influences can be effectively compensated by this arrangement.Type: GrantFiled: December 18, 1998Date of Patent: June 6, 2000Assignee: Zellweger Luwa AGInventor: Markus Schoni
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Patent number: 6057693Abstract: The composition of an electrically conductive mixture, such as a mixture of gasoline and alcohol, is measured using a single measurement cell having a first electrode and a second electrode with a measurement space therebetween for receiving a specimen of the mixture. With a specimen of the mixture in the measurement space, the first electrode is alternatively connected to a reference discharge voltage, preferably ground, and to an applied voltage through a resistor. A first operational state encompasses the period when the first electrode is connected to the reference discharge voltage and a second operational state encompasses the period when the first electrode is connected to the applied voltage through the resistor. A first operational state peak voltage is measured during the first operational state, and a second operational state peak voltage is measured during the second operational state.Type: GrantFiled: August 27, 1996Date of Patent: May 2, 2000Assignee: Raytheon CompanyInventors: J. Brian Murphy, John M. Brauninger, John McHardy, Clifford A. Megerle, Carl W. Townsend
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Patent number: 6028433Abstract: This invention relates to a fluid screening device, comprising: an impedance sensor including a cavity for holding a fluid to be screened, an impedance of the impedance sensor being affected by conditions of the fluid; an impedance measuring circuit for measuring the impedance of the impedance sensor with respect to at least one frequency; a processor for processing impedance data taken by the impedance measuring circuit for purposes of determining a condition of the fluid; and a connector which operatively couples the impedance sensor to the impedance measuring circuit, the connector allowing the impedance sensor to be selectively detached from the impedance measuring circuit.Type: GrantFiled: May 14, 1997Date of Patent: February 22, 2000Assignee: Reid Asset Management CompanyInventors: Margaret A. Cheiky-Zelina, Wayne A. Bush
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Patent number: 5917314Abstract: A device for locating the edges of wall studs includes a comparison circuit connected to each of three capacitive elements. As the device is moved along a wall, the comparison circuit monitors the relative charge time associated with each capacitive element, the charge times providing an indication of the relative capacitances of the three capacitive elements. Changes in the relative capacitances of the three elements as the device is moved along a wall are due to a change in the dielectric constant of the wall, which normally results from the presence of a wall stud behind the surface over which the device is moved. The comparison circuit uses differences in the measured relative capacitances of the first, second, and third capacitive elements to locate the edges of the stud.Type: GrantFiled: August 8, 1996Date of Patent: June 29, 1999Assignee: Zircon CorporationInventors: Charles E. Heger, Paul W. Dodd
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Patent number: 5861757Abstract: An instrument for measuring the dielectric constant of samples with complex or uncertain geometries that can include unusually shaped single sample pieces or collections of differently shaped sample pieces such as powders. The premise of the measurement technique is that a reference capacitor plate and a sample capacitor plate are exposed to a dynamically-changing solvent mixture. When the capacitance of these two fixtures become equal at the point at which a particular solvent mixture is reached, the dielectric constant of the sample is then known.Type: GrantFiled: November 25, 1996Date of Patent: January 19, 1999Assignee: International Business Machine CorporationInventors: Gareth Geoffrey Hougham, Alfred Viehbeck, Stanley Joseph Whitehair
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Patent number: 5828222Abstract: An output open circuit test method including the steps of inputting the data of a predetermined charging current upper limit value and a predetermined test voltage and a predetermine test charging current time zone into a test apparatus, then employing a high voltage to the test sample, and then driving the test apparatus to measure the current between two ends of the test sample and to compare the measured current value with the predetermined charging current upper limit value, and then letting the test apparatus to start testing the leakage current of the test sample when the measured current value is below the predetermined charging current upper limit value.Type: GrantFiled: June 5, 1997Date of Patent: October 27, 1998Assignees: Extech Electronics Co., Ltd., Associated Research, Inc.Inventor: Pin-Yi Chen
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Patent number: 5668309Abstract: An apparatus for detecting particles within a hydraulic system having a hydraulic line includes a capacitor formed by a pair of electrodes. A charging circuit produces a charging current of constant magnitude. The charging current is used to charge the capacitor to a predetermined voltage. A timing circuit measures the elapsed time between the time at which the charging circuit begins to produce the charging current and the time at which the capacitor has been charged to the predetermined voltage. The timing circuit produces a pulse width modulated signal. The magnitude of the pulse width modulated signal is indicative of the time difference. A controller receives the pulse width modulated signal and detects particles by comparing the duration of each pulse with a reference pulse.Type: GrantFiled: August 31, 1995Date of Patent: September 16, 1997Assignee: Caterpillar Inc.Inventors: George Codina, Chandrasekar Ramamoorthy, Donna J. Murr
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Patent number: 5612622Abstract: An apparatus for identifying components associated with the liquid in an electrically non-conductive container utilizing a pair of electrodes. The container extends along a particular dimension such that the first electrode is placed adjacent the exterior of the container and at least a second electrode is placed adjacent the exterior of the container in spaced configuration from the first electrode and along the particular dimension of the container. A generated output signal is coupled into the liquid via the first electrode. The output signal is coupled to the second electrode after passing through the liquid component. The output waveforms are analyzed to determine the electrical characteristics of the liquid in order to identify a component within the container.Type: GrantFiled: December 28, 1994Date of Patent: March 18, 1997Assignee: Optical Solutions, Inc.Inventors: Don S. Goldman, Steven Wilcox
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Patent number: 5602485Abstract: A device for checking the weights of individual capsules in a stream of capsules by passing the stream of capsules past a capacitance sensor which measures the capacitance of each capsule as representative of the capsule weight, and passing the stream of capsules past a velocity sensor which measures the velocity of each capsule as representative of the capsule weight. The measured capacitance and measured velocity values are each compared against preset ranges of values, and a capsule is mechanically deflected from the moving stream if the comparison shows either measured value to be outside the respective preset range of values.Type: GrantFiled: January 16, 1996Date of Patent: February 11, 1997Assignee: Modern Controls, Inc.Inventors: William N. Mayer, Daniel W. Mayer, Roger C. Oestreich
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Patent number: 5563518Abstract: The gas fraction and the slip velocity are proportional to the difference in dielectric readings taken in a vertically upward flowing stream of oil/water/gas and in a vertically downwardly flowing stream of the same mixture. Actual water cuts are obtained by appropriately adjusting the dielectric water cut readings.Type: GrantFiled: July 5, 1994Date of Patent: October 8, 1996Assignee: Texaco Inc.Inventors: Michael G. Durrett, Wayne F. Warren, Raymond C. Hedges, Gregory J. Hatton
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Patent number: 5541580Abstract: A body detector (10) detects when a body (12) is absent from a region (26) being monitored. The body (12) has a different dielectric constant than air. The region (26) is configured as a capacitor (20) in which the body (12), if present, serves as a dielectric. The capacitance of the capacitor (20) is measured (28). This measurement influences a baseline value (30). The capacitance is measured (38) a second time. The second measurement is checked to verify that it is within minimum (42) and maximum (46) values. In addition, it is checked to verify that it is within a more narrow range (54) that is defined in response to the baseline value. The second measurement is then used to adjust the baseline value and the process repeats. The range (54) within which the capacitance must stay slowly adapts to changes in the capacitance of the capacitor (20). Abrupt changes in the capacitance cause an alarm to be annunciated.Type: GrantFiled: August 9, 1995Date of Patent: July 30, 1996Assignee: Motorola, Inc.Inventors: Charles Gerston, Thomas M. Fox