Patents by Inventor Masaki Hirakata

Masaki Hirakata 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).

  • Publication number: 20210313922
    Abstract: Provided is a motor drive device comprising a motor control unit that controls a plurality of upper arm-side switching elements and a plurality of lower arm-side switching elements provided to an inverter for driving a motor; a current determination unit that determines whether a motor current flowing through at least one switching element of the plurality of upper arm-side switching elements and the plurality of lower arm-side switching elements is equal to or smaller than a threshold value; and a short-circuit control unit that performs switching between all-on of the plurality of upper arm-side switching elements and all-on of the plurality of lower arm-side switching elements, on condition that the motor current is equal to or smaller than the threshold value, in a short-circuiting operation of alternately switching all-on of the plurality of upper arm-side switching elements and all-on of the plurality of lower arm-side switching elements.
    Type: Application
    Filed: February 24, 2021
    Publication date: October 7, 2021
    Inventor: Masaki HIRAKATA
  • Patent number: 11012021
    Abstract: An inverter device includes gate driving circuits for upper and lower arms of a bridge circuit, a first power supply supplying a power supply voltage to each driving circuit, and a second power supply having a reference potential different from that of the first power supply. The inverter device also includes a first fail-safe circuit having a reference potential common to the first power supply and generating driving commands with respect to the upper and lower arms, and a second fail-safe circuit having a reference potential common to the second power supply and generating driving commands with respect to the upper or lower arm. The lower arm gate driving circuit has two driving command input functions having different reference potentials, one function inputs the driving commands from the first fail-safe circuit, and the other function inputs the driving commands from the second fail-safe circuit.
    Type: Grant
    Filed: February 21, 2020
    Date of Patent: May 18, 2021
    Assignee: FUJI ELECTRIC CO., LTD.
    Inventor: Masaki Hirakata
  • Patent number: 10998808
    Abstract: A power conversion device, that includes a drive circuit 11a that drives a switching element 4 included in an upper-arm for one of three phases, a drive circuit 11b that drives a switching element 5 included in a lower-arm for the one phase, and a control circuit 9 that transmits a control signal to the drive circuits 11a, 11b, is provided. The power conversion device includes power supply circuits 12a, 12b that provide power to the drive circuits 11a, 11b, respectively, a low-voltage power supply 6 that supplies power to one of the power supply circuits, 12a, and a high-voltage power supply 1 that supplies power to the other of the power supply circuits, 12b. Accordingly, it is possible to reliably protect a system: by realizing minimal redundancy of the power supply, the power supply generation circuit, etc.; and by realizing the short-circuit mode at the time of error occurrence.
    Type: Grant
    Filed: July 23, 2018
    Date of Patent: May 4, 2021
    Assignee: FUJI ELECTRIC CO., LTD.
    Inventors: Masaki Hirakata, Akihiro Odaka
  • Publication number: 20210111656
    Abstract: Provided is a motor driving apparatus including: an upper-arm gate driving circuit; a lower-arm gate driving circuit; a first rotation detection unit powered by a first power source; a second rotation detection unit powered by a second power source; a first fail safe circuit that performs, by use of a detection signal from the first rotation detection unit, a fail safe control on a gate driving circuit powered at least by the first power source, from among the upper-arm gate driving circuit and the lower-arm gate driving circuit; and a second fail safe circuit that performs, by use of a detection signal from the second rotation detection unit, a fail safe control on a gate driving circuit powered at least by the second power source, from among the upper-arm gate driving circuit and the lower-arm gate driving circuit.
    Type: Application
    Filed: August 24, 2020
    Publication date: April 15, 2021
    Inventor: Masaki HIRAKATA
  • Publication number: 20200195186
    Abstract: An inverter device includes gate driving circuits for upper and lower arms of a bridge circuit, a first power supply supplying a power supply voltage to each driving circuit, and a second power supply having a reference potential different from that of the first power supply. The inverter device also includes a first fail-safe circuit having a reference potential common to the first power supply and generating driving commands with respect to the upper and lower arms, and a second fail-safe circuit having a reference potential common to the second power supply and generating driving commands with respect to the upper or lower arm. The lower arm gate driving circuit has two driving command input functions having different reference potentials, one function inputs the driving commands from the first fail-safe circuit, and the other function inputs the driving commands from the second fail-safe circuit.
    Type: Application
    Filed: February 21, 2020
    Publication date: June 18, 2020
    Inventor: Masaki HIRAKATA
  • Publication number: 20200012205
    Abstract: An electrophotographic photoreceptor includes a conductive substrate; an undercoat layer on the conductive substrate; a charge generating layer on the undercoat layer; a charge transporting layer on the charge generating layer; and an inorganic protective layer on the charge transporting layer. The undercoat layer, the charge transporting layer, and the inorganic protective layer each have a film elastic modulus of 5 GPa or more.
    Type: Application
    Filed: January 29, 2019
    Publication date: January 9, 2020
    Applicant: FUJI XEROX CO.,LTD.
    Inventors: Yoichi KIGOSHI, Takeshi IWANAGA, Nobuyuki TORIGOE, Masaki HIRAKATA, Hideya KATSUHARA, Keisuke KUSANO
  • Publication number: 20190346781
    Abstract: An electrophotographic photoreceptor of an exemplary embodiment includes a conductive substrate, an undercoat layer on the conductive substrate, a charge generating layer on the undercoat layer, a charge transporting layer on the charge generating layer, and an inorganic protective layer on the charge transporting layer, in which formula: 0<A/B<0.5 is satisfied, where A represents a thickness of a layer having the lowest film elastic modulus among the layers disposed on the conductive substrate other than the charge generating layer, and B represents a total thickness of the layers disposed on the conductive substrate.
    Type: Application
    Filed: February 6, 2019
    Publication date: November 14, 2019
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Hideya KATSUHARA, Takeshi IWANAGA, Masaki HIRAKATA, Nobuyuki TORIGOE, Yoichi KIGOSHI
  • Publication number: 20190302632
    Abstract: Provided is an electrophotographic photoreceptor including: a conductive substrate; a single-layer type photosensitive layer that is provided on the conductive substrate; an inorganic protective layer that is provided on the single-layer type photosensitive layer; wherein layers that are interposed between the conductive substrate and the inorganic protective layer have a total thickness of 10 ?m to 25 ?m.
    Type: Application
    Filed: July 30, 2018
    Publication date: October 3, 2019
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Nobuyuki TORIGOE, Takeshi IWANAGA, Masaki HIRAKATA, Hideya KATSUHARA, Yoichi KIGOSHI, Yukimi KAWABATA
  • Patent number: 10317809
    Abstract: An image forming apparatus includes a photoreceptor that includes a conductive substrate, a photosensitive layer, and an inorganic surface layer arranged in that order, the inorganic surface layer containing a group 13 element and oxygen; a charging unit; an electrostatic image-forming unit; a developing unit; a transfer unit; a cleaning unit that performs cleaning by causing the cleaning blade to contact the surface of the photoreceptor; and a supply unit that supplies a fatty acid metal salt to a position where the cleaning blade in the cleaning unit contacts the photoreceptor. When the fatty acid metal salt is supplied, a portion of the surface of the photoreceptor downstream of the supply unit and upstream of the cleaning unit in a rotating direction of the photoreceptor is covered with a metal derived from the fatty acid metal salt at a coverage of about 40% or more.
    Type: Grant
    Filed: March 8, 2018
    Date of Patent: June 11, 2019
    Assignee: FUJI XEROX CO., LTD.
    Inventors: Masaki Hirakata, Hideya Katsuhara, Nobuyuki Torigoe, Yasutaka Matsumoto, Takeshi Iwanaga
  • Publication number: 20190094722
    Abstract: An image forming apparatus includes a photoreceptor that includes a conductive substrate, a photosensitive layer, and an inorganic surface layer arranged in that order, the inorganic surface layer containing a group 13 element and oxygen; a charging unit; an electrostatic image-forming unit; a developing unit; a transfer unit; a cleaning unit that performs cleaning by causing the cleaning blade to contact the surface of the photoreceptor; and a supply unit that supplies a fatty acid metal salt to a position where the cleaning blade in the cleaning unit contacts the photoreceptor. When the fatty acid metal salt is supplied, a portion of the surface of the photoreceptor downstream of the supply unit and upstream of the cleaning unit in a rotating direction of the photoreceptor is covered with a metal derived from the fatty acid metal salt at a coverage of about 40% or more.
    Type: Application
    Filed: March 8, 2018
    Publication date: March 28, 2019
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Masaki HIRAKATA, Hideya KATSUHARA, Nobuyuki TORIGOE, Yasutaka MATSUMOTO, Takeshi IWANAGA
  • Patent number: 10185276
    Abstract: An image forming apparatus includes an electrophotographic photoreceptor, a charging device, an electrostatic latent image forming device, a developing device, a transfer device, and a cleaning device, and further includes an intercepting device that includes an intercepting member separated from the electrophotographic photoreceptor by a gap so that a distance from the surface of the electrophotographic photoreceptor to the intercepting member is about 0.3 to 0.9 (inclusive) times a volume-average particle size of toner particles. The intercepting member is used to intercept residual toner particles at a position downstream of the transfer device and upstream of the cleaning device in a rotation direction of the electrophotographic photoreceptor, the residual toner particles remaining on the surface of the electrophotographic photoreceptor.
    Type: Grant
    Filed: March 8, 2017
    Date of Patent: January 22, 2019
    Assignee: FUJI XEROX CO., LTD.
    Inventors: Masaki Hirakata, Takashi Imai
  • Publication number: 20180331616
    Abstract: A power conversion device, that includes a drive circuit 11a that drives a switching element 4 included in an upper-arm for one of three phases, a drive circuit 11b that drives a switching element 5 included in a lower-arm for the one phase, and a control circuit 9 that transmits a control signal to the drive circuits 11a, 11b, is provided. The power conversion device includes power supply circuits 12a, 12b that provide power to the drive circuits 11a, 11b, respectively, a low-voltage power supply 6 that supplies power to one of the power supply circuits, 12a, and a high-voltage power supply 1 that supplies power to the other of the power supply circuits, 12b. Accordingly, it is possible to reliably protect a system: by realizing minimal redundancy of the power supply, the power supply generation circuit, etc.; and by realizing the short-circuit mode at the time of error occurrence.
    Type: Application
    Filed: July 23, 2018
    Publication date: November 15, 2018
    Inventors: Masaki HIRAKATA, Akihiro ODAKA
  • Patent number: 10073364
    Abstract: Electrophotographic photoreceptor including a conductive substrate, an organic photosensitive layer on an outer peripheral surface of the conductive substrate, and an inorganic protective layer on an outer peripheral surface of the organic photosensitive layer, the inorganic protective layer containing gallium and oxygen. A volume resistivity of an inner region of the inorganic protective layer, the inner region extending 0.2 ?m or about 0.2 ?m from an inner peripheral surface of the inorganic protective layer in a thickness direction, and a volume resistivity of an outer region of the inorganic protective layer, the outer region extending 0.2 ?m or about 0.2 ?m from an outer peripheral surface of the inorganic protective layer in the thickness direction, are both 6.0×107 ?·cm or more and 4.0×108 ?·cm or less or about 6.0×107 ?·cm or more and about 4.0×108 ?·cm or less.
    Type: Grant
    Filed: July 12, 2017
    Date of Patent: September 11, 2018
    Assignee: FUJI XEROX CO., LTD.
    Inventors: Yoichi Kigoshi, Masaki Hirakata, Satomi Kashiwagi, Nobuyuki Torigoe, Takeshi Iwanaga, Takashi Imai
  • Patent number: 10001714
    Abstract: An electrophotographic photosensitive member includes a conductive base; an organic photosensitive layer disposed on the conductive base, the organic photosensitive layer including a layer that constitutes a surface and contains a charge transport material, a binder resin having a viscosity-average molecular weight less than about 50,000, and silica particles in an amount of about 40% by weight or more; and an inorganic protective layer disposed on the organic photosensitive layer.
    Type: Grant
    Filed: January 15, 2016
    Date of Patent: June 19, 2018
    Assignee: FUJI XEROX CO., LTD.
    Inventors: Masaki Hirakata, Takeshi Iwanaga, Nobuyuki Torigoe, Hideya Katsuhara, Yoichi Kigoshi, Takashi Imai, Fumiaki Mera
  • Publication number: 20180095372
    Abstract: Electrophotographic photoreceptor including a conductive substrate, an organic photosensitive layer on an outer peripheral surface of the conductive substrate, and an inorganic protective layer on an outer peripheral surface of the organic photosensitive layer, the inorganic protective layer containing gallium and oxygen. A volume resistivity of an inner region of the inorganic protective layer, the inner region extending 0.2 ?m or about 0.2 ?m from an inner peripheral surface of the inorganic protective layer in a thickness direction, and a volume resistivity of an outer region of the inorganic protective layer, the outer region extending 0.2 ?m or about 0.2 ?m from an outer peripheral surface of the inorganic protective layer in the thickness direction, are both 6.0×107 ?·cm or more and 4.0×108 ?·cm or less or about 6.0×107 ?·cm or more and about 4.0×108 ?·cm or less.
    Type: Application
    Filed: July 12, 2017
    Publication date: April 5, 2018
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Yoichi KIGOSHI, Masaki HIRAKATA, Satomi KASHIWAGI, Nobuyuki TORIGOE, Takeshi IWANAGA, Takashi IMAI
  • Publication number: 20180067443
    Abstract: An image forming apparatus includes an electrophotographic photoreceptor, a charging device, an electrostatic latent image forming device, a developing device, a transfer device, and a cleaning device, and further includes an intercepting device that includes an intercepting member separated from the electrophotographic photoreceptor by a gap so that a distance from the surface of the electrophotographic photoreceptor to the intercepting member is about 0.3 to 0.9 (inclusive) times a volume-average particle size of toner particles. The intercepting member is used to intercept residual toner particles at a position downstream of the transfer device and upstream of the cleaning device in a rotation direction of the electrophotographic photoreceptor, the residual toner particles remaining on the surface of the electrophotographic photoreceptor.
    Type: Application
    Filed: March 8, 2017
    Publication date: March 8, 2018
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Masaki HIRAKATA, Takashi IMAI
  • Patent number: 9904204
    Abstract: A unit for an image forming apparatus includes an electrophotographic photoreceptor that includes a conductive substrate, a photosensitive layer provided on the conductive substrate, and a surface layer provided so as to contact with an outermost surface of the photosensitive layer, and an exposure section that exposes the electrophotographic photoreceptor with a light having a wavelength (?) (nm) so as to form an electrostatic latent image on a charged surface of the electrophotographic photoreceptor, wherein a surface roughness (Rz1) (nm) of the outermost surface of the photosensitive layer satisfies an expression of [(Rz1)?(?)/(4×(n2))] where a refractive index of the surface layer is set as (n2), and an outermost surface of the surface layer has a surface shape different from the outermost surface of the photosensitive layer.
    Type: Grant
    Filed: February 4, 2016
    Date of Patent: February 27, 2018
    Assignee: FUJI XEROX CO., LTD.
    Inventors: Takeshi Iwanaga, Takashi Imai, Hideya Katsuhara, Masaki Hirakata, Yoichi Kigoshi, Nobuyuki Torigoe, Fumiaki Mera
  • Patent number: 9864286
    Abstract: An electrophotographic photoreceptor includes an electroconductive substrate, an organic photosensitive layer on the electroconductive substrate and an inorganic protective layer on the organic photosensitive layer, wherein a layer that forms a surface of the organic photosensitive layer contains a charge transporting material, a binder resin, and a silica particle; the inorganic protective layer contains a group 13 element, an oxygen atom, and a hydrogen atom; a sum of element constitution ratios of the group 13 element, the oxygen atom, and the hydrogen atom to all elements constituting the inorganic protective layer is equal to or more than 90 atomic %; and an element composition ratio (oxygen atom/group 13 element) of the oxygen atom and the group 13 element is 1.0 or more and less than 1.5.
    Type: Grant
    Filed: July 8, 2016
    Date of Patent: January 9, 2018
    Assignee: FUJI XEROX CO., LTD.
    Inventors: Fumiaki Mera, Nobuyuki Torigoe, Masaki Hirakata, Hideya Katsuhara, Yoichi Kigoshi, Satomi Kashiwagi, Yuko Iwadate, Kenji Kajiwara, Tatsuki Sano, Takashi Imai, Takeshi Iwanaga
  • Patent number: 9831801
    Abstract: A three-phase inverter system, in one configuration, includes an inverter main circuit and a control circuit. The inverter system includes current sensors which detect output currents in, for example, U- and W-phases, respectively, the inverter main circuit includes a semiconductor switching device with a current sense which is provided in, for example, the V-phase. The control circuit is configured to detect current values from the current sensors inputted thereto and produce driving signals, which drive the upper-arm and lower-arm semiconductor switching devices of the inverter main circuit, based on the detected current values, estimate, based on a detected signal from the semiconductor switching device with the current sense, an output current value in the one of the three series circuits, and detect failure in at least one of the current sensors based on the detected current values from the two current sensors and the estimated output current value.
    Type: Grant
    Filed: August 8, 2016
    Date of Patent: November 28, 2017
    Assignee: FUJI ELECTRIC CO., LTD.
    Inventor: Masaki Hirakata
  • Publication number: 20170269486
    Abstract: An electrophotographic photoreceptor includes an electroconductive substrate, an organic photosensitive layer on the electroconductive substrate and an inorganic protective layer on the organic photosensitive layer, wherein a layer that forms a surface of the organic photosensitive layer contains a charge transporting material, a binder resin, and a silica particle; the inorganic protective layer contains a group 13 element, an oxygen atom, and a hydrogen atom; a sum of element constitution ratios of the group 13 element, the oxygen atom, and the hydrogen atom to all elements constituting the inorganic protective layer is equal to or more than 90 atomic %; and an element composition ratio (oxygen atom/group 13 element) of the oxygen atom and the group 13 element is 1.0 or more and less than 1.5.
    Type: Application
    Filed: July 8, 2016
    Publication date: September 21, 2017
    Applicant: FUJI XEROX CO., LTD.
    Inventors: Fumiaki MERA, Nobuyuki TORIGOE, Masaki HIRAKATA, Hideya KATSUHARA, Yoichi KIGOSHI, Satomi KASHIWAGI, Yuko IWADATE, Kenji KAJIWARA, Tatsuki SANO, Takashi IMAI, Takeshi IWANAGA