With Frequency Signal Response, Change Or Processing Circuit Patents (Class 324/681)
  • Patent number: 7696763
    Abstract: A fluid sensor is constructed to have a pair of electrodes whereas between electrodes there are not additional materials designated to adsorb analytes if their concentrations are high, or there are adsorbents if the analyte concentrations are low. An alternating current voltage of varying frequencies is applied to the electrodes of the sensor by an alternating current device. In return, it detects electrical properties such as impedance and its components, reactance, resistance, and phase angles of the sensor with analytes whereas the analytes reside in or pass through the electrodes at each frequency. Thus a spectrum of electrical properties of the analyte can be established at various applied frequencies. The electrical properties are analyzed by a pattern recognition process, and compared with those of the known fluids. Therefore, the fluid can be detected and identified. A reference sensor is provided with the same configuration of the fluid sensor.
    Type: Grant
    Filed: May 22, 2008
    Date of Patent: April 13, 2010
    Inventor: Yizhong Sun
  • Publication number: 20100028027
    Abstract: In a method or system for processing a measurement signal for detecting a property of a toner mark, the toner mark is produced and detected. A measurement signal is output, a signal curve of the measurement signal being determined. A temporal measurement window is provided for detecting a property of the toner mark, the temporal measurement window having a beginning and an end.
    Type: Application
    Filed: December 12, 2007
    Publication date: February 4, 2010
    Inventor: Ralph Dorfner
  • Patent number: 7652488
    Abstract: The invented method for measuring the health of a solid rocket propellant includes embedding at least one piezoelectric capacitance sensor in the propellant, where the capacitance of the sensor is a function of a modulus of the propellant, and where the position is selected to measure manifestations of stress failure as a consequence of changes in the shear modulus. The capacitance of the sensor is measured at a predetermined frequency. The capacitance of the piezoelectric capacitance sensor is converted into a digital representation which is then converted into the digital representation of a modulus (or gradient modulus). In subsequent analysis, the modulus (or gradient of the modulus) is correlated to the health of the solid rocket propellant.
    Type: Grant
    Filed: April 26, 2007
    Date of Patent: January 26, 2010
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventor: Craig M. Lopatin
  • Publication number: 20090295411
    Abstract: A method includes measuring a first frequency response of an electrode at a first frequency across a range of environmental conditions, measuring a second frequency response of the electrode at a second frequency across the range of environmental conditions, and comparing the first and second frequency responses measured to define a data set representing an effect of the environmental conditions. An occupant detection system includes an electrode and a detector circuit. The detector circuit is configured to measure an actual frequency response of the electrode and compare the actual frequency response to the data set to determine the effect of the current environmental condition.
    Type: Application
    Filed: April 30, 2009
    Publication date: December 3, 2009
    Applicant: DELPHI TECHNOLOGIES, INC.
    Inventor: Mark C. Hansen
  • Publication number: 20090295412
    Abstract: A occupant detection system includes an electronic device in communication with a sensor. The system detects an occupant by way of measuring an impedance of an electric field emitted by the sensor. The electronic device is configured to acquire data values from an output signal of the sensor, and reduce the effect of transient electrical interference on the acquired data values and adapt for sustained electrical interference on the acquired data values. A method includes acquiring a new data value, determining whether the new data value represents transient interference, and capturing the new data value if the new data value is free of transient interference and rejecting the new data value if the new data value represents transient interference.
    Type: Application
    Filed: May 1, 2009
    Publication date: December 3, 2009
    Applicant: DELPHI TECHNOLOGIES, INC.
    Inventor: Dennis P. Griffin
  • Patent number: 7619421
    Abstract: 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: Grant
    Filed: August 31, 2006
    Date of Patent: November 17, 2009
    Assignee: Microtune (Texas), L.P.
    Inventors: Jan-Michael Stevenson, Timothy M. Magnusen
  • Patent number: 7598752
    Abstract: The disclosure relates to a touch sensing device and method. An embodiment of the disclosed method includes starting to count with a counter while charging a sensing point which has distributed capacitance periodically, then transferring the charge on the sensing point to a second capacitor. Next, the voltage on the second capacitor is compared with a reference voltage, and if the former exceeds the latter, the counter stops counting and saving the value. If the voltage on the second capacitor is less than the reference voltage, the sensing point is judged to determine whether it is in touching state or in non-touching state according to the saved count value while discharging the second capacitor, clearing the counter after the discharge, then restarting the method. Using the device and method of this disclosure, the touching sensing action can be tested accurately.
    Type: Grant
    Filed: December 29, 2006
    Date of Patent: October 6, 2009
    Assignee: Beijing, Sigmachip Co., Ltd.
    Inventor: Zhiqian Li
  • Publication number: 20090243633
    Abstract: A capacitance sensor, having at least one electrode is disclosed. A frequency spread signal generation circuit is coupled to the at least one electrode to apply a frequency spread signal based on a spread sequence. A periodic signal with a frequency is coupled to the at least one electrode. A frequency controller is coupled to the frequency spread signal generation circuit to vary the frequency of the periodic signal. A receiver circuit is coupled to the at least one or a further electrode to receive a version of the frequency spread signal which depends on a capacitance applied to the at least one electrode. An evaluation circuit is coupled to the receiver circuit to determine a capacitance value based on the received, dependent version of the frequency spread signal.
    Type: Application
    Filed: December 5, 2008
    Publication date: October 1, 2009
    Inventors: Georg Brasseur, Thomas Bretterklieber, Dirk Hammerschmidt, Gert Holler, Tobias Werth, Hubert Zangl
  • Publication number: 20090153151
    Abstract: An obstacle detection system includes a static capacitance detection module including a sensor strip for detecting a static capacitance, an RF oscillator connected to the sensor strip, a phase lock loop section for maintaining the oscillation frequency of the RF oscillator to a selected value and a first MCU for controlling the operation of the phase lock loop section, a control module including a second MCU for remotely controlling the first MCU of the static capacitance detection module and a transmission line for connecting the static capacitance detection module and the control module and transmitting the information acquired by the first MCU so as to be transmitted to the control module, a control signal to be transmitted from the second MCU to the first MCU and drive power of the static capacitance detection module.
    Type: Application
    Filed: December 17, 2008
    Publication date: June 18, 2009
    Applicant: Auto Tech Co. Ltd.
    Inventors: Seung Won CHO, Kwang Seok Jeong
  • Publication number: 20090096468
    Abstract: When moving a head rest front portion in a full-open position direction, an ECU determines that the head rest front portion comes close to an occupant head portion on the basis of a detection result of an electrostatic capacitance sensor so as to stop the head rest front portion, and determines that the head rest front portion comes close to the occupant head portion on the basis of an absolute capacitance change with respect to a reference electrostatic capacitance value of the electrostatic capacitance sensor. Alternatively, the ECU determines that the head rest front portion comes close to the occupant head portion on the basis of a change amount of the electrostatic capacitance value of the electrostatic capacitance sensor.
    Type: Application
    Filed: November 10, 2006
    Publication date: April 16, 2009
    Applicants: AISIN SEIKI KABUSHIKI KAISHA, TOYOTA JIDOSHA KABUSHIKI KAISHA, TOYOTA BOSHOKU KABUSHIKI KAISHA
    Inventors: Koichi Hirota, Koji Aoki, Manabu Tsuruta, Kiyoka Matsubayashi, Motomi Iyoda, Tatsuhiro Okawa, Fumitoshi Akaike
  • Publication number: 20090066346
    Abstract: The invention relates to a circuit device and a method for detecting the presence of an object in the vicinity of a motor vehicle. The aim of the invention is to provide solutions which allow monitoring the vicinity of a motor vehicle with regard to the presence of an object. In particular, the aim of the invention is to provide solutions which allow detecting the approach of human body parts to danger-relevant structures, such as for example soft top devices, window openings, door openings and trunk lids, and taking the appropriate safety measures. According to the invention, this problem is solved by a motor vehicle that comprises a detection circuit with a first electrode system, a second electrode system and an alternative current generator for generating a potential difference between the two electrode systems, the first electrode system being arranged in the lower region of the vehicle for inputting the shift current events in the region supporting the vehicle.
    Type: Application
    Filed: December 18, 2006
    Publication date: March 12, 2009
    Applicant: IDENT TECHNOLOGY AG
    Inventor: Claus Kaltner
  • Patent number: 7425836
    Abstract: In a method for determining capacitance, a first time-varying signal is driven on a first terminal of a first capacitor and a second time-varying signal is driven on a first terminal of a second capacitor, where the first time-varying signal and the second time-varying signal have a pre-determined phase relationship with each other. These signals are received on second terminals of the first capacitor and the second capacitor and demodulated using a periodic signal to produce demodulated signals. This periodic signal has the same fundamental frequency as the first time-varying signal and the second time-varying signal. A DC component in the demodulated signals is then determined by filtering the demodulated signals, and the sign of the DC component is used to determine a relative capacitance of the first capacitor and the second capacitor.
    Type: Grant
    Filed: August 23, 2006
    Date of Patent: September 16, 2008
    Assignee: Sun Microsystems, Inc.
    Inventors: Alex Chow, Robert D. Hopkins, Justin M. Schauer
  • Publication number: 20080061801
    Abstract: In a method for determining capacitance, a first time-varying signal is driven on a first terminal of a first capacitor and a second time-varying signal is driven on a first terminal of a second capacitor, where the first time-varying signal and the second time-varying signal have a pre-determined phase relationship with each other. These signals are received on second terminals of the first capacitor and the second capacitor and demodulated using a periodic signal to produce demodulated signals. This periodic signal has the same fundamental frequency as the first time-varying signal and the second time-varying signal. A DC component in the demodulated signals is then determined by filtering the demodulated signals, and the sign of the DC component is used to determine a relative capacitance of the first capacitor and the second capacitor.
    Type: Application
    Filed: August 23, 2006
    Publication date: March 13, 2008
    Inventors: Alex Chow, Robert D. Hopkins, Justin M. Schauer
  • Patent number: 7292050
    Abstract: A method for determining misalignment between two semiconductor dies is described in which signals are transmitted through a first subset of an array of proximity connectors that are proximate to a surface of one of the semiconductor dies and received through a second subset of an array of proximity connectors that are proximate to a surface of the other semiconductor die. A spatial beat frequency is determined from the received signals. This spatial beat frequency corresponds to misalignment-induced aliasing of spatial frequencies associated with the first subset of the array of proximity connectors and the second subset of the array of proximity connectors. The misalignment is then determined using the spatial beat frequency.
    Type: Grant
    Filed: August 23, 2006
    Date of Patent: November 6, 2007
    Assignee: Sun Microsystems, Inc
    Inventors: Alex Chow, Ronald Ho, Robert D. Hopkins
  • Patent number: 7259574
    Abstract: A sensor device for measuring frequency and amplitude of a varying force signal is provided. The sensor device comprises a sensing element defined by a plurality of even numbered planar segments symmetrically disposed about a central axis, a protective housing for housing, an interface element comprising a pick up member, a planar mechanical actuator, a transfer member adapted to receive varying signals from the pick up, amplify the signals picked up and transfer the amplified signals to the said mechanical actuator; and leads for transmitting said output signals outside the sensing device for processing.
    Type: Grant
    Filed: May 13, 2005
    Date of Patent: August 21, 2007
    Inventor: Vaidya Avinash Shrikrishna
  • Patent number: 7173438
    Abstract: A method for determining capacitance includes alternately charging a capacitor to a first voltage and discharging the capacitor to a second voltage, generating an output signal having a frequency that is a function of a time period, and determining the capacitance based on the frequency of the output signal. The time period is selected from at least one of: (a) a time period needed to charge the capacitor from the second voltage to the first voltage and (b) a time period needed to discharge the capacitor from the first voltage to the second voltage.
    Type: Grant
    Filed: May 18, 2005
    Date of Patent: February 6, 2007
    Assignee: Seagate Technology LLC
    Inventors: Pooranampillai Samuel Pooranakaran, Vasudevan Seshadri Kumar, Manoj Kumar Dey, Chung See Fook
  • Patent number: 7138809
    Abstract: An electrical capacitance proximity sensor with high detector sensitivity has an insulating substrate, a detector electrode and an earth electrode formed in a fixed pattern on one face of the insulating substrate, and a detector circuit which detects an object approaching the detector electrode and the earth electrode by detecting the capacitance between the detector electrode and the earth electrode. The detector electrode is formed in a shape such that it surrounds the earth electrode.
    Type: Grant
    Filed: May 12, 2005
    Date of Patent: November 21, 2006
    Assignee: Fujikura Ltd.
    Inventors: Yasushi Nakamura, Fumio Yajima, Nobumasa Misaki
  • Patent number: 7126352
    Abstract: In a method and device for determining the moisture content and conductivity in the ground and in bulk materials, a capacitive sensor is disposed in the ground or the bulk material, the sensor is charged from a constant external voltage supply with a given initial current from a given first voltage threshold value to a given second voltage threshold value and either a voltage/time diagram is determined or a first charging time required for charging the sensor from the first to the second voltage threshold values by the constant external voltage supply is determined and a second charging time is determined wherein either the initial current and/or at least one of the two voltage threshold values are altered and the water content and the conductivity are determined by verification of the two charging times or of the voltage/time diagram.
    Type: Grant
    Filed: May 24, 2005
    Date of Patent: October 24, 2006
    Assignee: GSF - Forschungszentrum für Umwelt und Gesundheit GmbH
    Inventor: Ruth Bernhard
  • Patent number: 7123028
    Abstract: The invention provides a force detector in which power consumption is suppressed. Four electrodes E11 through E14 are formed on a substrate, and an elastic deformable body formed of a rubber film is disposed thereon. A conductive coating is applied on the lower surface of the elastic deformable body to provide a displacing conductive layer 26. Four capacitance elements C11 through C14 are comprised by the electrodes E11 through E14 and the displacing conductive layer 26 opposed to the electrodes. The capacitance values thereof are converted into voltage values V11 through V14 by C/V converter circuit 50, and based on operation by signal processing circuit 60, an external force applied to the elastic deformable body is detected.
    Type: Grant
    Filed: January 10, 2005
    Date of Patent: October 17, 2006
    Assignee: Wacoh Corporation
    Inventors: Kazuhiro Okada, Nobumitsu Taniguchi
  • Patent number: 7119551
    Abstract: An improved two loop capacitive sensor oscillator circuit converts a transducer capacitance to a frequency and includes a first loop to create an oscillatory waveform having a frequency related to a capacitance of the capacitive transducer. The first loop includes a resistor. The resistor is electrically coupled to a capacitor. The resistor is also electrically coupled to the capacitive transducer. The capacitive transducer is electrically coupled to an input of a first inverter gate. A second loop oscillates at the frequency of the first loop and further generates a second waveform of a substantially square wave shape at the same frequency. The second loop is electrically coupled to the first loop and the output of a third inverter gate is substantially a square wave at the frequency related to the capacitance of the capacitive transducer.
    Type: Grant
    Filed: October 14, 2005
    Date of Patent: October 10, 2006
    Assignee: Welch Allyn, Inc.
    Inventor: Kenneth J. Burdick
  • Patent number: 7119554
    Abstract: An electrical capacitance proximity sensor for detecting a nearby object takes a normal operation mode for detecting the nearby object approaching and a self-diagnostic mode for detecting a correct connection between a sensor section and a detecting circuit section. The detecting circuit section is provided with a buffer controller which supplies a second oscillation signal having the same phase and voltage as a first oscillation signal applied to a guard electrode in the normal operation mode, and stops supplying the second oscillation signal in the self-diagnostic mode. A control circuit determines whether the sensor section is correctly connected to the detecting circuit section base on the change in the detecting signal in the normal operation mode and the self-diagnostic mode.
    Type: Grant
    Filed: July 12, 2005
    Date of Patent: October 10, 2006
    Assignee: Fujikura Ltd.
    Inventors: Yasushi Nakamura, Akira Kamijima
  • Patent number: 7091727
    Abstract: A method and an integrated circuit for detecting capacitance variation includes the steps of: generating a detection frequency for capacitance variation and a detection frequency which lags the detection frequency by k times, wherein the detection frequencies are based on a time divisional format; operating the detection frequencies to produce a difference frequency; operating variation rate of the difference frequency; and comparing the variation rate of the difference frequency with a predetermined detection level, and outputting a signal indicative of capacitance variation if the variation rate of the difference frequency is greater than the detection level.
    Type: Grant
    Filed: September 1, 2005
    Date of Patent: August 15, 2006
    Assignee: AD Semiconductor Co., Ltd.
    Inventor: Sang-Chuel Lee
  • Patent number: 6980009
    Abstract: Disclosed is an on-chip test device for testing the thickness of gate oxides in transistors. A ring oscillator provides a ring oscillator output and an inverter receives the ring oscillator output as an input. The inverter is coupled to a gate oxide and the inverter receives different voltages as power supplies. The difference between the voltages provides a measurement of capacitance of the gate oxide. The difference between the voltages is less than or equal to approximately one-third of the difference between a second set of voltages provided to the ring oscillator. The capacitance of the gate oxide comprises the inverse of the frequency of the ring oscillator output multiplied by the difference between the voltages, less a capacitance constant for the test device. This capacitance constant is for the test device alone, and does not include any part of the capacitance of the gate oxide. The measurement of capacitance of the gate oxide is used to determine the thickness of the gate oxide.
    Type: Grant
    Filed: October 22, 2003
    Date of Patent: December 27, 2005
    Assignee: International Business Machines Corporation
    Inventors: Edward P. Maciejewski, Phung T. Nguyen, Edward J. Nowak
  • Patent number: 6943564
    Abstract: In an active-drive type pixel structure comprising at least TFT for control, TFT for drive, and a capacitor for charge retention, it can be easily inspected whether the functions of TFTs and the capacitor are normal or not. In an active-drive type pixel structure comprising TFT (Tr1) for control, TFT (Tr2) for drive, and a capacitor for charge retention, one terminal of a dummy load W for inspection is connected to a drain of the TFT for drive, and the other terminal of the load W is connected to a line 3 for inspection. By measuring an electric current Id obtained on the line 3 for inspection while changing a voltage supplied to a data line 2a, it can be inspected whether the functions of TFTs and the capacitor are normal or not. The dummy load W is configured to be melted and cut by burning off the load W with a laser beam or by passing a predetermined electric current in the load W after completion of inspection.
    Type: Grant
    Filed: January 27, 2004
    Date of Patent: September 13, 2005
    Assignee: Tohoku Pioneer Corporation
    Inventors: Takayoshi Yoshida, Shozaburo Sakaguchi
  • Patent number: 6914425
    Abstract: A measurement circuit for measuring input voltages in an automatic test system includes a pedestal source, a differential amplifier, and a feedback amplifier. The differential amplifier measures a “residue,” i.e., a difference between an input signal and a pedestal signal from the pedestal source, which is programmed to equal an expected input voltage. The feedback amplifier boosts the residue before it is presented to the differential amplifier, and thus allows the differential amplifier to be operated at lower gain than is typically used in conventional topologies. Consequently, the effect of the errors in the differential amplifier are reduced.
    Type: Grant
    Filed: April 29, 2003
    Date of Patent: July 5, 2005
    Assignee: Teradyne, Inc.
    Inventor: David G. Leip
  • Patent number: 6911873
    Abstract: A method and circuit are disclosed for detecting the performance of an oscillator circuit. In particular, the circuit may detect a signal, such as the output of the oscillator circuit, failing to oscillate as desired. The second circuit may be capable of detecting whether the signal oscillates at a frequency that is less than a predetermined frequency. The second circuit may include timing circuits for determining whether the signal remains in a first logic state for at least a predetermined period of time and whether the signal remains in a second logic state for at least the predetermined period of time.
    Type: Grant
    Filed: June 24, 2003
    Date of Patent: June 28, 2005
    Assignee: STMicroelectronics, Inc.
    Inventors: Rong Yin, Thomas Allyn Coker
  • Patent number: 6859048
    Abstract: The invention provides a force detector in which power consumption is suppressed. Four electrodes E11 through E14 are formed on a substrate, and an elastic deformable body formed of a rubber film is disposed thereon. A conductive coating is applied on the lower surface of the elastic deformable body to provide a displacing conductive layer 26. Four capacitance elements C11 through C14 are comprised by the electrodes E11 through E14 and the displacing conductive layer 26 opposed to the electrodes. The capacitance values thereof are converted into voltage values V11 through V14 by C/V converter circuit 50, and based on operation by signal processing circuit 60, an external force applied to the elastic deformable body is detected.
    Type: Grant
    Filed: February 12, 2004
    Date of Patent: February 22, 2005
    Assignee: Wacoh Corporation
    Inventors: Kazuhiro Okada, Nobumitsu Taniguchi
  • Patent number: 6809529
    Abstract: The invention provides a force detector in which power consumption is suppressed. Four electrodes (E11-E14) are formed on a substrate, and an elastic deformable body formed of a ruber film is disposed thereon. A conductive coating is applied on the lower surface of the elastic deformable body to provide a displacing conductive layer (26). Four capacitance elements (C11-C14) are comprised by the electrodes (E11-E14) and the displacing conductive layer (26) opposed to the electrodes. The capacitance values thereof are converted into voltage values (V11-V14) by C/V converter circuit (50), and based on operation by signal processing circuit (60), an external force applied to the elastic deformable body is detected. A pair of contacting electrodes (E15) and (E16) are formed on the substrate, and when an external force with a predetermined strength or more is applied, the elastic deformable body deforms, and the displacing conductive layer (26) comes into contact with both electrodes (E15) and (E16).
    Type: Grant
    Filed: December 17, 2001
    Date of Patent: October 26, 2004
    Assignee: Wacoh Corporation
    Inventors: Kazuhiro Okada, Nobumitsu Taniguchi
  • Publication number: 20040160235
    Abstract: The invention provides a force detector in which power consumption is suppressed. Four electrodes E11 through E14 are formed on a substrate, and an elastic deformable body formed of a rubber film is disposed thereon. A conductive coating is applied on the lower surface of the elastic deformable body to provide a displacing conductive layer 26. Four capacitance elements C11 through C14 are comprised by the electrodes E11 through E14 and the displacing conductive layer 26 opposed to the electrodes. The capacitance values thereof are converted into voltage values V11 through V14 by C/V converter circuit 50, and based on operation by signal processing circuit 60, an external force applied to the elastic deformable body is detected.
    Type: Application
    Filed: February 12, 2004
    Publication date: August 19, 2004
    Applicant: WACOH CORPORATION
    Inventors: Kazuhiro Okada, Nobumitsu Taniguchi
  • Patent number: 6774644
    Abstract: A method for tracking the MOS oxide thickness by the native threshold voltage of a “native” MOS transistor without channel implantation for the purpose of compensating MOS capacitance variations is achieved. The invention makes use of the fact that in MOS devices the threshold voltage is proportionally correlated to the oxide thickness of said MOS device. Said threshold voltage can therefore be used to build a reference voltage Vx+Vth which accurately tracks the MOS capacitance variations in integrated circuits. Circuits are achieved to create a frequency reference and a capacitance reference using said method. Additionally a method is introduced to create a capacitance reference in integrated circuits using said MOSFET capacitors.
    Type: Grant
    Filed: April 10, 2002
    Date of Patent: August 10, 2004
    Assignee: Dialog Semiconductor GmbH
    Inventor: Matthias Eberlein
  • Publication number: 20040090237
    Abstract: A circuit for measuring absolute spread in capacitors implemented in planary technology. A charge pump supplying a charge current to an internal capacitor (Cint) is used, the voltage across the internal capacitor (Cint) being coupled through a comparator for comparing the voltage with first and second threshold levels. A bistable multivibrator reverses the direction of the charge current, to charge the internal capacitor (Cint) when the voltage decreases below the second threshold level, and to decharge the internal capacitor (Cint) when the voltage increases above the first threshold level. The charge current is determined by a reference voltage that is provided across an external resistor (Rext), the first and second threshold levels defining a voltage range being proportional to the reference voltage. An output signal of the bistable multivibrator is coupled to frequency measuring means to compare the repetition frequency thereof with a reference frequency.
    Type: Application
    Filed: November 21, 2002
    Publication date: May 13, 2004
    Inventor: Wolfdietrich Georg Kasperkovitz
  • Patent number: 6728647
    Abstract: A method of estimating a capacitance of each resource in a programmable logic device (PLD) is described. The current drawn by a reference circuit implemented in the PLD is measured at a given frequency and operating voltage. The capacitance of the reference circuit is calculated using the current drawn, the frequency, and the operating voltage. The current drawn by a resource load coupled to the reference circuit is measured at the given frequency and operating voltage. The capacitance of the resource load coupled to the reference circuit is calculated using the current drawn, the frequency, and the operating voltage. The capacitance of the resource load may be calculated by subtracting the capacitance of the reference circuit from the capacitance of the resource load coupled to the reference circuit.
    Type: Grant
    Filed: February 21, 2001
    Date of Patent: April 27, 2004
    Assignee: Xilinx, Inc.
    Inventors: Suresh Sivasubramaniam, Siuki Chan
  • Patent number: 6714025
    Abstract: A method and an apparatus for synchronous demodulation of the multiply modulated rotation rate signal of a rotation rate sensor which comprises a spring-mass system that oscillates at its natural resonant frequency, and at least one capacitor for ascertaining a Coriolis effect acting on the spring-mass system or a rotation rate, the rotation rate being ascertained by a time-variable capacitance change, brought about by the rotation rate, of the at least one capacitor by multiple demodulation of a multiply modulated electrical signal that comprises a time-variable first electrical signal and a second electrical signal, overlaid thereon, at the natural resonant frequency of the rotation rate sensor, the amplitude of the second electrical signal of the time-variable capacitance change of the at least one capacitor being correspondingly modulated.
    Type: Grant
    Filed: February 19, 2002
    Date of Patent: March 30, 2004
    Assignee: Robert Bosch GmbH
    Inventors: Jens Mohaupt, Wolfram Bauer
  • Patent number: 6657444
    Abstract: A capacitance-based position sensor configured to sense relative position of a pair of objects. The sensor includes capacitor circuitry having a capacitor that varies in capacitance with relative position of the pair of objects. A source is coupled to the capacitor circuitry, and is configured to apply a time-varying input to the capacitor circuitry. The capacitor circuitry is configured to yield a time-varying, capacitance-dependent output in response to application of the time-varying input from the source. The sensor further includes an integrator configured to integrate, for a predetermined time period, a received signal that is based upon the time-varying, capacitance-dependent output from the capacitor circuitry. The integration yields an integrator output which is proportional to the value of the capacitance. This output is usable to determine relative position of the objects.
    Type: Grant
    Filed: January 11, 2002
    Date of Patent: December 2, 2003
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventor: Donald J. Fasen
  • Patent number: 6566894
    Abstract: A device and method for detecting oxidizable and/or reducible gases in the air for controlling ventilation plants in buildings or motor vehicles and for monitoring combustion processes or waste gas analysis by a capacitance sensor that detects change in sensor capacities at two different frequencies. Alternating currents having at least two frequencies is passed through a heated sensor between contact electrodes of the sensor and a polycrystalline metal oxide sensor material and an evaluation circuit measures a change in capacitance between the electrodes and sensor material. A change in capacitance measured at a first frequency indicates the presence of reducible gases while a change in sensor capacitance at a second frequency indicates the presence of oxidizable gases. Variations in sensor ohmic resistance at the two frequencies are also considered.
    Type: Grant
    Filed: October 30, 1998
    Date of Patent: May 20, 2003
    Assignee: Rosemarie Brand-Gerhart
    Inventor: Hanns Rump
  • Patent number: 6559658
    Abstract: An electromagnetic field presence sensor independently evaluates the presence or absence of an object in a variety of frequency ranges. Conflicting indications of the presence of the object in these different ranges, such as may be caused by electromagnetic interference, is resolved through a voting system. In this way, band limited noise may be resisted while improving the sensitivity of the sensor and without reducing its response speed.
    Type: Grant
    Filed: September 27, 2000
    Date of Patent: May 6, 2003
    Assignee: Rockwell Automation Technologies, Inc.
    Inventor: David D. Brandt
  • Publication number: 20030030452
    Abstract: The invention provides a force detector in which power consumption is suppressed. Four electrodes E11 through E14 are formed on a substrate, and an elastic deformable body formed of a rubber film is disposed thereon. A conductive coating is applied on the lower surface of the elastic deformable body to provide a displacing conductive layer 26. Four capacitance elements C11 through C14 are comprised by the electrodes E11 through E14 and the displacing conductive layer 26 opposed to the electrodes. The capacitance values thereof are converted into voltage values V11 through V14 by C/V converter circuit 50, and based on operation by signal processing circuit 60, an external force applied to the elastic deformable body is detected.
    Type: Application
    Filed: December 17, 2001
    Publication date: February 13, 2003
    Applicant: WACOH CORPORATION
    Inventors: Kazuhiro Okada, Nobumitsu Taniguchi
  • Patent number: 6501284
    Abstract: 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: Grant
    Filed: August 28, 2000
    Date of Patent: December 31, 2002
    Assignee: STMicroelectronics, Inc.
    Inventor: Giovanni Gozzini
  • Patent number: 6486683
    Abstract: A position sensor comprises a capacitive transducer and an inductor connected in series with the transducer. The transducer is a differential capacitor whose total admittance is essentially independent of changes in the sensed position. The total capacitance and inductance resonate at the fundamental frequency of a generator that provides a drive voltage and the resulting voltage across the sensor is thus substantially greater than the drive voltage. This increases the current through the transducer, and consequently increases the sensitivity of the sensor.
    Type: Grant
    Filed: December 30, 1999
    Date of Patent: November 26, 2002
    Assignee: GSI Lumonics, Inc.
    Inventor: Michael B. Nussbaum
  • Patent number: 6483323
    Abstract: A projectile fuze detects transitions between target layers by an electronic antenna radiating laterally into the target material and coupled to a pullable oscillator whose frequency shifts as the target material changes while the projectile penetrates. A frequency shift threshold detector relates the observed frequency shifts to a stored target profile to detonate the projectile after the desired layer penetration.
    Type: Grant
    Filed: January 16, 1996
    Date of Patent: November 19, 2002
    Assignee: General Dynamics Decision Systems, Inc.
    Inventors: Monty W. Bai, Gerald James Moore, Ralph Eugene Foresman
  • Patent number: 6448792
    Abstract: The edge portion of an electro-conductive material inserted between a pair of the transmitting electrodes of triangular plate disposed flatly in opposite directions each other and the receiving electrode. The exciting signal source applies respectively the alternating voltage signal S1 with frequency f1 on one of the transmitting electrodes and the alternating voltage signal S2 with frequency f2 on the other transmitting electrode. The insertion extent of the strip edge of the electro-conductive material is evaluated with the ratio between the current I1 with frequency f1 and the current I2 with frequency f2 generated on the receiving electrode.
    Type: Grant
    Filed: May 30, 2000
    Date of Patent: September 10, 2002
    Assignee: Nireco Corporation
    Inventors: Hirokazu Yoshida, Akira Shimotori
  • Publication number: 20020101252
    Abstract: A structure for being used in measuring a capacitance of a capacitor is provided. The structure includes a plurality of input terminals having an operating voltage and an operating frequency, a first quasi-inverting circuit having a first parasitic capacitor for generating a first current and electrically connected with the input terminals, a second quasi-inverting circuit having a second parasitic capacitor and a first reference capacitor for generating a second current and electrically connected with the first quasi-inverting circuit, and a third quasi-inverting circuit having the capacitor, a third parasitic capacitor and a second reference capacitor for generating a third current and electrically connected with the quasi-inverting circuit.
    Type: Application
    Filed: April 30, 2001
    Publication date: August 1, 2002
    Applicant: National Science Council
    Inventors: Huang-Chung Cheng, Gwo-Yann Lee, Cheng-Jer Yang
  • Patent number: 6373264
    Abstract: An apparatus for detecting an impedance variable in response to a sensed physical amount of a sensor is provided which comprises an impedance-frequency conversion unit and a counter. The impedance-frequency conversion unit converts the sensor impedance to an oscillation signal a frequency of which corresponds to the sensor impedance. The impedance-frequency conversion unit comprises an impedance-voltage converter for providing a voltage corresponding to the sensor impedance, and a Wien bridge oscillator including an element an impedance of which varies in response to the voltage from the impedance-voltage converter, for generating the oscillation signal. The Wien bridge oscillator is capable of generating a square wave signal as the oscillation signal. The counter counts the number of waves (or wave number) of the oscillation signal in a predetermined time period to output a count value which can be handled as a digital signal.
    Type: Grant
    Filed: October 8, 1999
    Date of Patent: April 16, 2002
    Assignee: Sumitomo Metal Industries, Ltd.
    Inventors: Toshiyuki Matsumoto, Yoshihiro Hirota, Muneo Harada, Takaya Miyano
  • Publication number: 20020011851
    Abstract: The invention relates to a method and a device for detecting oxidizable and/or reducible gases in the air for the purpose of controlling ventilation plants in buildings or motor vehicles and for the purpose of monitoring combustion processes and/or waste gas catalyst plants, by employing at least one current-passing and heated sensor (5.1; 7.2) furnished with contact electrodes (5.9; 5.10) and with a metallic sensor material, preferably of polycrystalline metal oxide, as well as employing an electric evaluation circuit. The sensor (5.1; 7.2) is passed through by an alternating current, which alternating current either comprises at least two alternating currents of different frequency or is switched between at least two frequencies, wherein, on the one hand, the change of the capacities between the sensor material and the contact electrodes (5.9; 5.
    Type: Application
    Filed: October 30, 1998
    Publication date: January 31, 2002
    Inventor: HANS RUMP
  • Patent number: 6333680
    Abstract: An exemplary embodiment of the invention is a method of characterizing capacitances of a plurality of integrated circuit interconnects. The method includes coupling a first oscillator to a first integrated circuit interconnect and coupling a second oscillator to a second integrated circuit interconnect. The first oscillator is activated to characterize the sum of (i) coupling capacitance between the first integrated-circuit interconnect and the second integrated-circuit interconnect and (ii) ground capacitance between the first integrated-circuit interconnect and a ground. In addition, both of the first oscillator and the second oscillator are activated to characterize the ground capacitance between the first integrated-circuit interconnect and the ground.
    Type: Grant
    Filed: October 2, 2000
    Date of Patent: December 25, 2001
    Assignee: International Business Machines Corporation
    Inventors: Howard H. Smith, Alina Deutsch, Ching-Lung L. Tong, Rolf H. Nijhuis
  • Patent number: 6310482
    Abstract: A capacitance gauge tracking apparatus used for an exposure system for manufacturing a semiconductor device, a method for tracking a surface of the semiconductor device, a leveling apparatus and a leveling method are provided. The capacitance gauge tracking apparatus includes a ground unit, a probe unit and a gauge unit. The ground unit is connected to a semiconductor substrate. The probe unit is spaced apart from the surface of the semiconductor substrate to be tracked and a constant current of at least two frequency bands is applied to the probe unit. A constant current of a low frequency is applied to the probe unit to thereby perform global leveling by global tracking of the entire surface of the semiconductor substrate and a constant current of a high frequency is applied to the probe unit to thereby perform local leveling by local tracking on the semiconductor substrate.
    Type: Grant
    Filed: June 3, 1999
    Date of Patent: October 30, 2001
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Jin-seog Hong
  • Patent number: 6262589
    Abstract: The pixel capacitances of an LCD array can be inspected easily and in a short time without being affected by the capacitance of the tester system. On the first occasion, pixel capacitance CP is charged with pixel voltage VP and line capacitance CS (CS>>CP) that is connected in parallel with pixel capacitance CP is charged with set voltage VS (VP≠VS). By connecting pixel capacitance CP and line capacitance CS is parallel, the difference voltage &Dgr;VS1 of the voltage of the line capacitance CS after the parallel connection and the set voltage VS that is charged thereon before the parallel connection is measured. On the second occasion, pixel capacitance CP is charged with pixel voltage VP and a known reference capacitance &Dgr;CS is connected in parallel with line capacitance CS, this being charged with set voltage VS.
    Type: Grant
    Filed: May 24, 1999
    Date of Patent: July 17, 2001
    Assignee: Asia Electronics, Inc.
    Inventor: Tadashi Tamukai
  • Patent number: 6184688
    Abstract: The insulation resistance of a capacitor is accurately measured within a short period of time by applying AC signals at two different frequencies f1 and f2 to the capacitor to measure the impedance Z1 and Z2 of the capacitor at each frequency. The series resistance Rs and capacity C of the capacitor are obtained from the impedance Z1 at the higher frequency f1, and the insulation resistance Rp of the capacitor is obtained from the impedance Z2, series resistance Rs and capacity C at the lower frequency f2.
    Type: Grant
    Filed: May 4, 1998
    Date of Patent: February 6, 2001
    Assignee: Murata Manufacturing Co., Ltd.
    Inventor: Gaku Kamitani
  • Patent number: 6130541
    Abstract: An adaptive output driver includes circuitry for sensing the capacitive loading of a driver circuit and then adjusting the drive output so that the output signal possess a desired slew rate. In one embodiment, the circuit of the present invention includes a capacitance sensor, a control circuit, and an output driver. The capacitance sensor measures the unknown load capacitance. The control circuit generates a control signal in response to the capacitive load measurement. The output driver receives the control signal and in response produces an output level which when supplied to the capacitive load produces an output signal having the desired slew rate.
    Type: Grant
    Filed: June 15, 1998
    Date of Patent: October 10, 2000
    Assignee: International Microcircuits Inc.
    Inventor: Ismail H. Ozguc
  • Patent number: 5963043
    Abstract: A method and apparatus for characterizing dimensions and parasitic capacitance between integrated-circuit interconnects are disclosed. The apparatus is a test structure including at least two substantially identical oscillators, at least two substantially identical counters, and a pulse generator. Each of the oscillators is connected to an integrated-circuit interconnect. Each of the counters is coupled to a respective oscillator. The pulse generator is utilized to inject a series of fixed-length clock pulses to each of the oscillators such that the parasitic capacitance of the integrated-circuit interconnects can be characterized by the ratio of oscillation periods of the oscillators to parasitic capacitances of the integrated-circuits.
    Type: Grant
    Filed: September 17, 1997
    Date of Patent: October 5, 1999
    Assignee: International Business Machines Corporation
    Inventor: Sani Richard Nassif