Patents by Inventor Koichi Yanagisawa

Koichi Yanagisawa has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 11522530
    Abstract: A waveform shaping circuit includes a capacitor, an impedance element, a switch circuit, and a switch control circuit. Opposite ends of the capacitor are connected to the input and output, respectively. One end of the impedance element supplies a target constant voltage to the output end of the capacitor. The switch circuit has a switch without a diode. When on, the switch applies the target constant voltage to the output. When off, it does not. The switch control circuit switches the switch on during a high voltage period in an AC component of an input pulse signal and switches the switch off during a low voltage period of the AC component. The circuit shapes the input pulse signal into an output pulse signal whose peak-to-peak voltage is equivalent to a peak-to-peak voltage of the AC component and whose voltage during the high voltage period is at the target constant voltage.
    Type: Grant
    Filed: December 1, 2021
    Date of Patent: December 6, 2022
    Assignee: HIOKI E.E. CORPORATION
    Inventors: Koichi Yanagisawa, Hiroyoshi Ikeda, Shin Kasai, Tomoharu Sakai
  • Patent number: 11349464
    Abstract: A waveform shaping circuit is configured without including a diode that is affected by temperature. The waveform shaping circuit includes: a capacitor with one end into which a differential signal Vd0 is inputted and another end connected to an output; an impedance element that has one end connected to the other end of the capacitor and another end into which a target constant voltage is applied; a switch circuit that is constructed of a series circuit with an impedance element and a switch without including a diode, has one end connected to the output, and has another end into which the target constant voltage is applied; and a switch control circuit that shifts the switch into an on state during a low voltage period in an AC component of the differential signal and shifts the switch to an off state during a high voltage period of the AC component.
    Type: Grant
    Filed: July 24, 2019
    Date of Patent: May 31, 2022
    Assignee: HIOKI E.E. CORPORATION
    Inventors: Koichi Yanagisawa, Hiroyoshi Ikeda, Shin Kasai, Tomoharu Sakai
  • Publication number: 20220094343
    Abstract: A waveform shaping circuit includes a capacitor, an impedance element, a switch circuit, and a switch control circuit. Opposite ends of the capacitor are connected to the input and output, respectively. One end of the impedance element supplies a target constant voltage to the output end of the capacitor. The switch circuit has a switch without a diode. When on, the switch applies the target constant voltage to the output. When off, it does not. The switch control circuit switches the switch on during a high voltage period in an AC component of an input pulse signal and switches the switch off during a low voltage period of the AC component. The circuit shapes the input pulse signal into an output pulse signal whose peak-to-peak voltage is equivalent to a peak-to-peak voltage of the AC component and whose voltage during the high voltage period is at the target constant voltage.
    Type: Application
    Filed: December 1, 2021
    Publication date: March 24, 2022
    Applicant: HIOKI E.E. CORPORATION
    Inventors: Koichi YANAGISAWA, Hiroyoshi IKEDA, Shin KASAI, Tomoharu SAKAI
  • Publication number: 20210344332
    Abstract: A waveform shaping circuit is configured without including a diode that is affected by temperature. The waveform shaping circuit includes: a capacitor with one end into which a differential signal Vd0 is inputted and another end connected to an output; an impedance element that has one end connected to the other end of the capacitor and another end into which a target constant voltage is applied; a switch circuit that is constructed of a series circuit with an impedance element and a switch without including a diode, has one end connected to the output, and has another end into which the target constant voltage is applied; and a switch control circuit that shifts the switch into an on state during a low voltage period in an AC component of the differential signal and shifts the switch to an off state during a high voltage period of the AC component.
    Type: Application
    Filed: July 24, 2019
    Publication date: November 4, 2021
    Applicant: HIOKI E.E. CORPORATION
    Inventors: Koichi YANAGISAWA, Hiroyoshi IKEDA, Shin KASAI, Tomoharu SAKAI
  • Patent number: 10841027
    Abstract: A broadcast wave synchronization signal converting device that synchronizes broadcast waves with GNSS signals on a reception side and corrects the broadcast waves to global standard times by use of correction values, thereby performing periodic calibrations of frequencies. The broadcast wave synchronization signal converting device includes: a PLL circuit reproduces system clocks on the basis of time information acquired from received broadcast waves; a subtractor (C1) subtracts, from a counter value corresponding to the periodic signal intervals of GNSS signals, a counter value of the system clocks counted at the signal intervals and outputs the difference value; a control amount adjustor calculates a control amount of synchronization as a correction value on the basis of the difference value; and a subtractor (B) subtracts the correction value from the acquired time information and sets the corrected time information to a PCR counter as the internal time information thereof.
    Type: Grant
    Filed: March 27, 2017
    Date of Patent: November 17, 2020
    Assignee: HITACHI KOKUSAI ELECTRIC INC.
    Inventors: Koichi Yanagisawa, Satoru Yasui
  • Patent number: 10767538
    Abstract: An energy conversion device includes a first acoustic wave generator, a second acoustic wave generator, and an output unit which are provided in a pipe member. The first acoustic wave generator has a thermal energy generator configured to generate thermal energy from electric energy, and converts the thermal energy generated by the thermal energy generator into acoustic energy to generate acoustic wave in working gas by a self-excited thermo acoustic vibration. The second acoustic wave generator converts thermal energy supplied from a heat supply source into acoustic energy and generates acoustic wave in working gas by a self-excited thermo acoustic vibration. The output unit converts the acoustic energy of the acoustic waves from the first acoustic wave generator and the second acoustic wave generator into cold energy to output.
    Type: Grant
    Filed: April 1, 2019
    Date of Patent: September 8, 2020
    Assignee: DENSO CORPORATION
    Inventors: Takuya Fuse, Motohiko Ueda, Yasumasa Hagiwara, Yuichi Ohno, Yukikatsu Ozaki, Koichi Yanagisawa
  • Publication number: 20200127748
    Abstract: A broadcast wave synchronization signal converting device that synchronizes broadcast waves with GNSS signals on a reception side and corrects the broadcast waves to global standard times by use of correction values, thereby performing periodic calibrations of frequencies. A The broadcast wave synchronization signal converting device includes: a PLL circuit reproduces system clocks on the basis of time information acquired from received broadcast waves; a subtractor (C1) subtracts, from a counter value corresponding to the periodic signal intervals of GNSS signals, a counter value of the system clocks counted at the signal intervals and outputs the difference value; a control amount adjustor calculates a control amount of synchronization as a correction value on the basis of the difference value; and a subtractor (B) subtracts the correction value from the acquired time information and sets the corrected time information to a PCR counter as the internal time information thereof.
    Type: Application
    Filed: March 27, 2017
    Publication date: April 23, 2020
    Inventors: Koichi YANAGISAWA, Satoru YASUI
  • Publication number: 20190226381
    Abstract: An energy conversion device includes a first acoustic wave generator, a second acoustic wave generator, and an output unit which are provided in a pipe member. The first acoustic wave generator has a thermal energy generator configured to generate thermal energy from electric energy, and converts the thermal energy generated by the thermal energy generator into acoustic energy to generate acoustic wave in working gas by a self-excited thermo acoustic vibration. The second acoustic wave generator converts thermal energy supplied from a heat supply source into acoustic energy and generates acoustic wave in working gas by a self-excited thermo acoustic vibration. The output unit converts the acoustic energy of the acoustic waves from the first acoustic wave generator and the second acoustic wave generator into cold energy to output.
    Type: Application
    Filed: April 1, 2019
    Publication date: July 25, 2019
    Inventors: Takuya FUSE, Motohiko UEDA, Yasumasa HAGIWARA, Yuichi OHNO, Yukikatsu OZAKI, Koichi YANAGISAWA
  • Patent number: 10012677
    Abstract: A voltage detecting apparatus detects a detection voltage generated in a detected object which is covered by an insulator. The voltage detecting apparatus includes: a detection electrode that is disposed so as to contact the insulator directly, or indirectly via another insulator; a vibrator that causes the insulator to vibrate; a current-to-voltage converter circuit that converts a detection current to a detection voltage signal, the detection current flowing from the detected object via the detection electrode to a reference voltage in a state where the insulator is being caused to vibrate, having an amplitude that is modulated in accordance with a potential difference between the detection voltage and the reference voltage, and being synchronized with vibration of the vibrator; and a detector circuit that detects a detection output indicating the potential difference from the detection voltage signal.
    Type: Grant
    Filed: September 30, 2015
    Date of Patent: July 3, 2018
    Assignee: HIOKI DENKI KABUSHIKI KAISHA
    Inventor: Koichi Yanagisawa
  • Publication number: 20160109486
    Abstract: A voltage detecting apparatus detects a detection voltage generated in a detected object which is covered by an insulator. The voltage detecting apparatus includes: a detection electrode that is disposed so as to contact the insulator directly, or indirectly via another insulator; a vibrator that causes the insulator to vibrate; a current-to-voltage converter circuit that converts a detection current to a detection voltage signal, the detection current flowing from the detected object via the detection electrode to a reference voltage in a state where the insulator is being caused to vibrate, having an amplitude that is modulated in accordance with a potential difference between the detection voltage and the reference voltage, and being synchronized with vibration of the vibrator; and a detector circuit that detects a detection output indicating the potential difference from the detection voltage signal.
    Type: Application
    Filed: September 30, 2015
    Publication date: April 21, 2016
    Applicant: HIOKI DENKI KABUSHIKI KAISHA
    Inventor: Koichi YANAGISAWA
  • Patent number: 9201100
    Abstract: A voltage detecting apparatus detects a detected AC voltage generated in a detected object, and includes a detection electrode that is disposed facing the detected object, a detection unit that operates on a floating power supply generated with a voltage of a reference voltage unit as a reference and outputs a detection signal, and a standard signal outputting unit that outputs a standard signal to the reference voltage unit. The voltage detecting apparatus also includes an insulating unit that inputs the detection signal and outputs an insulated detection signal, a feedback control unit that amplifies the insulated detection signal, and a signal extracting unit that amplifies the insulated detection and outputs a signal component as an output signal.
    Type: Grant
    Filed: June 26, 2014
    Date of Patent: December 1, 2015
    Assignee: HIOKI DENKI KABUSHIKI KAISHA
    Inventor: Koichi Yanagisawa
  • Publication number: 20140306733
    Abstract: A voltage detecting apparatus detects a detected AC voltage generated in a detected object, and includes a detection electrode that is disposed facing the detected object, a detection unit that operates on a floating power supply generated with a voltage of a reference voltage unit as a reference and outputs a detection signal, and a standard signal outputting unit that outputs a standard signal to the reference voltage unit. The voltage detecting apparatus also includes an insulating unit that inputs the detection signal and outputs an insulated detection signal, a feedback control unit that amplifies the insulated detection signal, and a signal extracting unit that amplifies the insulated detection and outputs a signal component as an output signal.
    Type: Application
    Filed: June 26, 2014
    Publication date: October 16, 2014
    Inventor: Koichi YANAGISAWA
  • Patent number: 8803506
    Abstract: A voltage detecting apparatus detects a detected AC voltage generated in a detected object. The voltage detecting apparatus includes a detection electrode that is disposed facing the detected object, and is capacitively coupled to the detected object. The voltage detecting apparatus also includes a bootstrap circuit that operates using a floating power supply generated with a reference voltage, and outputs a detection signal whose amplitude changes in accordance with an AC potential difference between the detected AC voltage and the reference voltage. The voltage detecting apparatus further includes an insulating circuit that inputs the detection signal and outputs an insulated detection signal that is electrically insulated from the detection signal, and a voltage generating circuit that amplifies the insulated detection signal to reduce the AC potential difference and generate the reference signal.
    Type: Grant
    Filed: May 30, 2012
    Date of Patent: August 12, 2014
    Assignee: Hioki Denki Kabushiki Kaisha
    Inventor: Koichi Yanagisawa
  • Publication number: 20120235666
    Abstract: A voltage detector detects a detected AC voltage generated in a detected object, and includes a detection electrode that is disposed facing the detected object, and an integrating circuit including an operational amplifier that has a first input terminal set at a reference voltage and a second input terminal connected to the detection electrode that integrates a detection current and outputs the integrated signal whose amplitude changes in accordance with the potential difference. The voltage detector also includes an insulating circuit that inputs the integrated signal and outputs the inputted integrated signal so as to be electrically insulated from an input side, and a voltage generating circuit that amplifies a signal based on the integrated signal so as to reduce the potential difference and generate the reference signal.
    Type: Application
    Filed: May 30, 2012
    Publication date: September 20, 2012
    Applicant: HIOKI DENKI KABUSHIKI KAISHA
    Inventor: Koichi YANAGISAWA
  • Patent number: 8222886
    Abstract: A voltage detector that detects an AC voltage in an object includes: an electrode disposed facing the object; a current-to-voltage converter that has a first input set at a reference voltage and a second input connected to the electrode and converts a detection current, which corresponds to a potential difference between the detected AC voltage and the reference voltage on a path including the electrode and a feedback circuit connected to the second input, to a detection signal; an integrating circuit that integrates the detection signal and outputs an integrated signal whose amplitude changes in accordance with the potential difference; an insulating circuit that inputs the detection signal or the integrated signal, and outputs the signal so as to be electrically insulated from the input; and a voltage generating circuit that generates the reference voltage by amplifying a signal based on the integrated signal to reduce the potential difference.
    Type: Grant
    Filed: June 16, 2009
    Date of Patent: July 17, 2012
    Assignee: Hioki Denki Kabushiki Kaisha
    Inventor: Koichi Yanagisawa
  • Patent number: 7834645
    Abstract: 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: Grant
    Filed: December 15, 2006
    Date of Patent: November 16, 2010
    Assignee: Hioki Denki Kabushiki Kaisha
    Inventor: Koichi Yanagisawa
  • Publication number: 20100283539
    Abstract: A voltage detection device detects an objective AC voltage arising on a detection object. The voltage detection device includes; a detecting electrode placed so as to be capacitively coupled with the detection object; a reference signal output section for outputting a reference signal; a detecting section outputting a detection signal changing its amplitude in accordance with both current values of a detection object current flowing according to the objective AC voltage and a reference current flowing according to the reference signal; and a signal extracting section for extracting a signal component of the objective AC voltage from an amplified detection signal and outputting the signal component as an output signal, the amplified detection signal being obtained through controlling a gain for amplifying the detection signal so as to make a signal component of the reference signal included in the detection signal have a predetermined value.
    Type: Application
    Filed: April 30, 2010
    Publication date: November 11, 2010
    Applicant: HIOKI DENKI KABUSHIKI KAISHA
    Inventor: Koichi YANAGISAWA
  • Publication number: 20090319210
    Abstract: A voltage detector that detects an AC voltage in an object includes: an electrode disposed facing the object; a current-to-voltage converter that has a first input set at a reference voltage and a second input connected to the electrode and converts a detection current, which corresponds to a potential difference between the detected AC voltage and the reference voltage on a path including the electrode and a feedback circuit connected to the second input, to a detection signal; an integrating circuit that integrates the detection signal and outputs an integrated signal whose amplitude changes in accordance with the potential difference; an insulating circuit that inputs the detection signal or the integrated signal, and outputs the signal so as to be electrically insulated from the input; and a voltage generating circuit that generates the reference voltage by amplifying a signal based on the integrated signal to reduce the potential difference.
    Type: Application
    Filed: June 16, 2009
    Publication date: December 24, 2009
    Applicant: HIOKI DENKI KABUSHIKI KAISHA
    Inventor: Koichi YANAGISAWA
  • Patent number: 7466145
    Abstract: A voltage measuring apparatus measures the voltage of a measured object and includes a detection electrode capable of being disposed facing the measured object, a variable capacitance circuit that is connected between the detection electrode and a reference potential and whose electrostatic capacitance can be changed, a voltage generating circuits that generates the reference potential, and a control unit. The control unit causes the voltage generating circuit to change the reference potential while the electrostatic capacitance of the variable capacitance circuit is being changed. A power measuring apparatus includes the voltage measuring apparatus and a current measuring apparatus that measures current flowing in the measured object, and measures power based on the current measured by the current measuring apparatus and the voltage measured by the voltage measuring apparatus.
    Type: Grant
    Filed: October 10, 2006
    Date of Patent: December 16, 2008
    Assignee: Hioki Denki Kabushiki Kaisha
    Inventor: Koichi Yanagisawa
  • Patent number: 7454725
    Abstract: The invention is aimed to analyze the characteristics of a transmission line only by inputting the specific distributed parameters without mesh dividing the transmission line to be analyzed into minimal unit required for the analysis. An arithmetic operation section 12 solves a differential equation regarding electromagnetic interaction of each line segment based on the predetermined distributed parameters, including a distributed self-inductance Li, a distributed resistance Ri, and a distributed capacitance ci and a distributed conductance gi in relation to a reference potential plane in the transmission line, and a distributed mutual inductance Mij, a distributed capacitance Cij, and a distributed conductance Gij between the transmission line and another transmission line, which are input from an input section 11, and calculates the characteristic data of the transmission line.
    Type: Grant
    Filed: July 6, 2004
    Date of Patent: November 18, 2008
    Assignee: Hioki Denki Kabushiki Kaisha
    Inventors: Koichi Yanagisawa, Fuchun Zhang, Toshiro Sato