Patents by Inventor Kouji Yasukawa

Kouji Yasukawa 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: 10928759
    Abstract: In a case where a drive instruction signal in a high level for placing a first triac provided to correspond to a heat generation member in a conduction state is output from a CPU, the first triac is placed in a conduction state after a second triac provided to correspond to a heat generation member is prohibited from being in a conduction state. In a case where a drive instruction signal in a low level for placing the second triac in a non-conduction state is output from the CPU, the state in which the second triac is prohibited from being in the conduction state is released after the first triac is placed in the non-conduction state.
    Type: Grant
    Filed: January 17, 2020
    Date of Patent: February 23, 2021
    Assignee: Canon Kabushiki Kaisha
    Inventors: Ken Oi, Nozomu Nakajima, Kouji Yasukawa
  • Publication number: 20200233350
    Abstract: In a case where a drive instruction signal in a high level for placing a first triac provided to correspond to a heat generation member in a conduction state is output from a CPU, the first triac is placed in a conduction state after a second triac provided to correspond to a heat generation member is prohibited from being in a conduction state. In a case where a drive instruction signal in a low level for placing the second triac in a non-conduction state is output from the CPU, the state in which the second triac is prohibited from being in the conduction state is released after the first triac is placed in the non-conduction state.
    Type: Application
    Filed: January 17, 2020
    Publication date: July 23, 2020
    Inventors: Ken Oi, Nozomu Nakajima, Kouji Yasukawa
  • Patent number: 10222735
    Abstract: A fixing apparatus includes a transformer, a heater, a temperature acquiring portion, and control portion. A first switching unit allows or cuts off power supply from a primary-side circuit to the heater by supplying power, and a second switching unit allows or cuts off power supply from the primary-side circuit to the temperature acquiring portion by supplying power. The power supply to the heater can be allowed or cut off according to the temperature of the heater acquired by the temperature acquiring portion. In addition, the control portion cuts off power supply from the primary-side circuit to the heater and power supply from the primary-side circuit to the temperature acquiring portion by controlling operations of the first switching unit and the second switching unit with the one signal.
    Type: Grant
    Filed: October 19, 2017
    Date of Patent: March 5, 2019
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kouji Yasukawa, Tsuyoshi Yamaguchi
  • Publication number: 20180113404
    Abstract: A fixing apparatus includes: first switching unit for allowing or cutting off power supply from a primary-side circuit to a heater when power is supplied; and second switching unit for allowing or cutting off power supply from the primary-side circuit to a temperature acquiring portion when power is supplied, and the power supply to the heater can be allowed or cut off according to the temperature of the heater acquired by the temperature acquiring portion. In the fixing apparatus, a control portion cuts off power supply from the primary-side circuit to the heater and power supply from the primary-side circuit to the temperature acquiring portion by controlling operations of the first switching unit and the second switching unit with one signal.
    Type: Application
    Filed: October 19, 2017
    Publication date: April 26, 2018
    Inventors: Kouji Yasukawa, Tsuyoshi Yamaguchi
  • Patent number: 9229376
    Abstract: A high voltage power supply including a first high voltage output unit that outputs a high voltage having a predetermined polarity, and including second and third high voltage output units that output a high voltage having a polarity opposite to the predetermined polarity. Rectification units that are connected to the first high voltage output unit separate a current path to the second high voltage output unit from a current path to the third high voltage output unit.
    Type: Grant
    Filed: August 29, 2012
    Date of Patent: January 5, 2016
    Assignee: CANON KABUSHIKI KAISHA
    Inventor: Kouji Yasukawa
  • Patent number: 9052670
    Abstract: In a color image forming apparatus, the amount of light of an exposure unit for a weak exposure is changed according to a remaining service life of a photosensitive drum when the weak exposure is performed for the background area of a corresponding photosensitive drum by using the exposure unit.
    Type: Grant
    Filed: August 5, 2014
    Date of Patent: June 9, 2015
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masaru Shimura, Hideo Nanataki, Shinsuke Kobayashi, Shinji Katagiri, Yasunari Watanabe, Hideaki Hasegawa, Kiyoto Toyoizumi, Kouji Yasukawa
  • Publication number: 20140341596
    Abstract: In a color image forming apparatus, the amount of light of an exposure unit for a weak exposure is changed according to a remaining service life of a photosensitive drum when the weak exposure is performed for the background area of a corresponding photosensitive drum by using the exposure unit.
    Type: Application
    Filed: August 5, 2014
    Publication date: November 20, 2014
    Inventors: Masaru Shimura, Hideo Nanataki, Shinsuke Kobayashi, Shinji Katagiri, Yasunari Watanabe, Hideaki Hasegawa, Kiyoto Toyoizumi, Kouji Yasukawa
  • Patent number: 8831444
    Abstract: In a color image forming apparatus, the amount of light of an exposure unit for a weak exposure is changed according to a remaining service life of a photosensitive drum when the weak exposure is performed for the background area of a corresponding photosensitive drum by using the exposure unit.
    Type: Grant
    Filed: March 7, 2012
    Date of Patent: September 9, 2014
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masaru Shimura, Hideo Nanataki, Shinsuke Kobayashi, Shinji Katagiri, Yasunari Watanabe, Hideaki Hasegawa, Kiyoto Toyoizumi, Kouji Yasukawa
  • Publication number: 20130064565
    Abstract: The high voltage power supply includes a first high voltage output unit that outputs a high voltage having a predetermined polarity, and second and third high voltage output units that output a high voltage having a polarity opposite to the predetermined polarity, wherein rectification units connected to the first high voltage output unit separate a current path to the second high voltage output unit from a current path to the third high voltage output unit.
    Type: Application
    Filed: August 29, 2012
    Publication date: March 14, 2013
    Applicant: CANON KABUSHIKI KAISHA
    Inventor: Kouji Yasukawa
  • Publication number: 20120230705
    Abstract: In a color image forming apparatus, the amount of light of an exposure unit for a weak exposure is changed according to a remaining service life of a photosensitive drum when the weak exposure is performed for the background area of a corresponding photosensitive drum by using the exposure unit.
    Type: Application
    Filed: March 7, 2012
    Publication date: September 13, 2012
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Masaru Shimura, Hideo Nanataki, Shinsuke Kobayashi, Shinji Katagiri, Yasunari Watanabe, Hideaki Hasegawa, Kiyoto Toyoizumi, Kouji Yasukawa
  • Patent number: 7898149
    Abstract: A power supply device is disclosed that outputs a voltage of a wider range with a single piezoelectric transformer. The power supply device includes a piezoelectric transformer 101 for applying an output voltage to a transfer member that transfers a toner image formed on an image bearing member onto a recording material. The power supply device further includes a generation unit 110 configured to generate a driving frequency for driving the piezoelectric transformer 101. A control unit 701 controls a spurious voltage by changing driving frequency characteristics of the power supply device in accordance with a target value of an output voltage Vout.
    Type: Grant
    Filed: December 10, 2007
    Date of Patent: March 1, 2011
    Assignee: Canon Kabushiki Kaisha
    Inventor: Kouji Yasukawa
  • Patent number: 7579749
    Abstract: A power supply device generates an output voltage by driving a piezoelectric transformer using a frequency signal. The power supply device includes a comparison unit configured to compare an output voltage and a voltage setting signal that sets the output voltage, and a voltage control oscillation unit configured to generate the frequency signal to drive the piezoelectric transformer based on comparison results of the comparison unit. The voltage control oscillation unit generates the frequency signal within a range between the resonant frequency and a spurious resonant frequency closest to the resonant frequency.
    Type: Grant
    Filed: July 6, 2006
    Date of Patent: August 25, 2009
    Assignee: Canon Kabushiki Kaisha
    Inventors: Hiroki Murata, Teruhiko Namiki, Osamu Nagasaki, Atsuhiko Yamaguchi, Tomohiro Nakamori, Takehiro Uchiyama, Kouji Yasukawa
  • Patent number: 7548708
    Abstract: A power supply unit in an image forming apparatus is provided. The power supply unit includes a piezoelectric transformer, an output voltage detecting circuit which detects the output voltage of the piezoelectric transformer, an output voltage control circuit which controls an output voltage from the piezoelectric transformer, and includes a comparator which receives an output voltage setting signal, together with an output voltage detecting signal fed back from the output voltage detecting circuit, to compare the output voltage setting signal and the output voltage detecting signal. The power supply unit also includes a driving frequency supplying circuit which generates a driving frequency signal of the piezoelectric transformer in accordance with a comparison result by the comparator, and supplies the driving frequency signal to the piezoelectric transformer. The time constant of the output voltage control circuit is longer than the time constant of the output voltage detecting circuit.
    Type: Grant
    Filed: January 20, 2006
    Date of Patent: June 16, 2009
    Assignee: Canon Kabushiki Kaisha
    Inventors: Osamu Nagasaki, Atsuhiko Yamaguchi, Tomohiro Nakamori, Takehiro Uchiyama, Kouji Yasukawa, Teruhiko Namiki, Hiroki Murata
  • Publication number: 20080260402
    Abstract: A power supply device is disclosed that outputs a voltage of a wider range with a single piezoelectric transformer. The power supply device includes a piezoelectric transformer 101 for applying an output voltage to a transfer member that transfers a toner image formed on an image bearing member onto a recording material. The power supply device further includes a generation unit 110 configured to generate a driving frequency for driving the piezoelectric transformer 101. A control unit 701 controls a spurious voltage by changing driving frequency characteristics of the power supply device in accordance with a target value of an output voltage Vout.
    Type: Application
    Filed: December 10, 2007
    Publication date: October 23, 2008
    Applicant: CANON KABUSHIKI KAISHA
    Inventor: Kouji Yasukawa
  • Patent number: 7425789
    Abstract: A power supply apparatus includes a piezoelectric transformer which outputs a voltage, a voltage-controlled oscillator which controls the frequency of an output signal in accordance with an input control signal, a power supply voltage supply element which is driven by a signal output from the voltage-controlled oscillator and applies a power supply voltage to the piezoelectric transformer, and an output voltage stop circuit (118) which outputs a signal for stopping driving the piezoelectric transformer on the basis of a control signal (Vcont).
    Type: Grant
    Filed: January 20, 2006
    Date of Patent: September 16, 2008
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kouji Yasukawa, Hiroshi Mano, Atsuhiko Yamaguchi, Osamu Nagasaki
  • Patent number: 7265479
    Abstract: In a power supply apparatus including a plurality of power supply circuits, each of the power supply circuits has a piezoelectric transformer, a rectification element which rectifies and smoothes a voltage output from the piezoelectric transformer in accordance with a load and outputs the voltage, a voltage-controlled oscillator which controls the frequency of an output signal in accordance with an input control signal, and a power supply voltage supply element which is driven by a signal output from the voltage-controlled oscillator and supplies a power supply voltage to the piezoelectric transformer. One power supply circuit includes a resonance frequency change unit which is connected to the output side of the piezoelectric transformer.
    Type: Grant
    Filed: January 20, 2006
    Date of Patent: September 4, 2007
    Assignee: Canon Kabushiki Kaisha
    Inventors: Atsuhiko Yamaguchi, Hiroshi Mano, Osamu Nagasaki, Kouji Yasukawa
  • Publication number: 20070007855
    Abstract: A power supply device generates an output voltage by driving a piezoelectric transformer using a frequency signal. The power supply device includes a comparison unit configured to compare an output voltage and a voltage setting signal that sets the output voltage, and a voltage control oscillation unit configured to generate the frequency signal to drive the piezoelectric transformer based on comparison results of the comparison unit. The voltage control oscillation unit generates the frequency signal within a range between the resonant frequency and a spurious resonant frequency closest to the resonant frequency.
    Type: Application
    Filed: July 6, 2006
    Publication date: January 11, 2007
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Hiroki Murata, Teruhiko Namiki, Osamu Nagasaki, Atsuhiko Yamaguchi, Tomohiro Nakamori, Takehiro Uchiyama, Kouji Yasukawa
  • Publication number: 20060273688
    Abstract: A power supply apparatus includes a piezoelectric transformer which outputs a voltage, a voltage-controlled oscillator which controls the frequency of an output signal in accordance with an input control signal, a power supply voltage supply element which is driven by a signal output from the voltage-controlled oscillator and applies a power supply voltage to the piezoelectric transformer, and an output voltage stop circuit (118) which outputs a signal for stopping driving the piezoelectric transformer on the basis of a control signal (Vcont).
    Type: Application
    Filed: January 20, 2006
    Publication date: December 7, 2006
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: KOUJI YASUKAWA, Hiroshi Mano, Atsuhiko Yamaguchi, Osamu Nagasaki
  • Publication number: 20060220495
    Abstract: In a power supply apparatus including a plurality of power supply circuits, each of the power supply circuits has a piezoelectric transformer, a rectification element which rectifies and smoothes a voltage output from the piezoelectric transformer in accordance with a load and outputs the voltage, a voltage-controlled oscillator which controls the frequency of an output signal in accordance with an input control signal, and a power supply voltage supply element which is driven by a signal output from the voltage-controlled oscillator and supplies a power supply voltage to the piezoelectric transformer. One power supply circuit includes a resonance frequency change unit which is connected to the output side of the piezoelectric transformer.
    Type: Application
    Filed: January 20, 2006
    Publication date: October 5, 2006
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: ATSUHIKO YAMAGUCHI, HIROSHI MANO, OSAMU NAGASAKI, Kouji Yasukawa
  • Publication number: 20060222398
    Abstract: A power supply unit in an image forming apparatus is provided. The power supply unit includes a piezoelectric transformer, an output voltage detecting circuit which detects the output voltage of the piezoelectric transformer, a comparator which receives an output voltage setting signal, together with an output voltage detecting signal fed back from the output voltage detecting circuit, to compare the output voltage setting signal and the output voltage detecting signal, and a driving frequency supplying circuit which generates the driving frequency of the piezoelectric transformer in accordance with a comparison result by the comparator, and supplies the resultant driving frequency to the piezoelectric transformer. The time constant of the output voltage setting signal is longer than the time constant of the output voltage detecting circuit.
    Type: Application
    Filed: January 20, 2006
    Publication date: October 5, 2006
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Osamu Nagasaki, Atsuhiko Yamaguchi, Tomohiro Nakamori, Takehiro Uchiyama, Kouji Yasukawa, Teruhiko Namiki, Hiroki Murata