Patents by Inventor Seiya Kitagawa

Seiya Kitagawa 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: 10941855
    Abstract: A controller performs control in a vehicle having a planetary gear mechanism, a forward clutch, an engine rotation sensor. a PRI rotation sensor, and a rotation sensor. The controller determines a rotation direction of a primary pulley corresponding to a rotation direction of a carrier on the basis of a rotation speed corresponding to a rotation speed of a sun gear, a rotation speed corresponding to a rotation speed of the carrier C, and a rotation speed of a ring gear, respectively.
    Type: Grant
    Filed: August 6, 2018
    Date of Patent: March 9, 2021
    Assignees: JATCO LTD, NISSAN MOTOR CO., LTD.
    Inventor: Seiya Kitagawa
  • Patent number: 10917080
    Abstract: A gate drive circuit has a capacitor and a gate drive voltage source connected in series with a gate terminal of a voltage-driven switching device. The gate drive source voltage feeds, as a gate drive voltage, a voltage higher than the sum of the voltage applied to a gate-source parasitic capacitance of the switching device when the switching device is in a steady ON state and the voltage applied to, of any circuit component interposed between the gate drive voltage source and the gate terminal of the switching device, a circuit component other than the capacitor (such as an upper transistor forming the output stage of the driver). No other circuit component (such as a resistor connected in parallel with the capacitor) is essential but the capacitor as the sole circuit component to be directly connected to the gate terminal of the switching device.
    Type: Grant
    Filed: March 30, 2017
    Date of Patent: February 9, 2021
    Assignee: Rohm Co., Ltd.
    Inventors: Tatsuya Yanagi, Hirotaka Otake, Takashi Sawada, Seiya Kitagawa
  • Publication number: 20200362959
    Abstract: A controller performs control in a vehicle having a planetary gear mechanism, a forward clutch, an engine rotation sensor. a PRI rotation sensor, and a rotation sensor. The controller determines a rotation direction of a primary pulley corresponding to a rotation direction of a carrier on the basis of a rotation speed corresponding to a rotation speed of a sun gear, a rotation speed corresponding to a rotation speed of the carrier C, and a rotation speed of a ring gear, respectively.
    Type: Application
    Filed: August 6, 2018
    Publication date: November 19, 2020
    Applicants: JATCO Ltd, NISSAN MOTOR CO., LTD.
    Inventor: Seiya KITAGAWA
  • Publication number: 20200248802
    Abstract: A vehicle includes a transmission having a variator and a sub-transmission mechanism, a controller serving as a shift control unit adapted to, as shift of the transmission, shift the sub-transmission mechanism and the variator so that a through speed ratio becomes a target speed ratio, and an engine serving as a torque increasing portion adapted to increase a torque inputted to the transmission in association with the shift of the transmission. The controller has a torque setting unit adapted to make a magnitude of an inclination larger as an increase amount of the engine rotation speed in association with the shift of the transmission is larger.
    Type: Application
    Filed: July 30, 2018
    Publication date: August 6, 2020
    Applicants: JATCO Ltd, NISSAN MOTOR CO., LTD.
    Inventors: Seiya KITAGAWA, Tomoaki HONMA
  • Publication number: 20170288657
    Abstract: A gate drive circuit has a capacitor and a gate drive voltage source connected in series with a gate terminal of a voltage-driven switching device. The gate drive source voltage feeds, as a gate drive voltage, a voltage higher than the sum of the voltage applied to a gate-source parasitic capacitance of the switching device when the switching device is in a steady ON state and the voltage applied to, of any circuit component interposed between the gate drive voltage source and the gate terminal of the switching device, a circuit component other than the capacitor (such as an upper transistor forming the output stage of the driver). No other circuit component (such as a resistor connected in parallel with the capacitor) is essential but the capacitor as the sole circuit component to be directly connected to the gate terminal of the switching device.
    Type: Application
    Filed: March 30, 2017
    Publication date: October 5, 2017
    Inventors: Tatsuya YANAGI, Hirotaka OTAKE, Takashi SAWADA, Seiya KITAGAWA
  • Patent number: 7899896
    Abstract: A user provides, in purchasing a predetermined electronic part used for a predetermined electronic circuit from an electronic parts maker, specifications for the predetermined electronic circuit to the electronic parts maker, the electronic parts maker calculates the electrical characteristics of the predetermined electronic part on the basis of the specifications for the predetermined electronic circuit which are provided from the user, and presents to the user the types of electronic part which are adaptable to the calculated electrical characteristics, and the user selects the desirable type from the types of electronic part which are presented by the electronic parts maker.
    Type: Grant
    Filed: September 28, 2007
    Date of Patent: March 1, 2011
    Assignees: Sanyo Electric Co., Ltd., Saga Sanyo Industries Co., Ltd.
    Inventors: Seiya Kitagawa, Satoshi Aikawa
  • Patent number: 7386811
    Abstract: A user provides, in purchasing a predetermined electronic part used for a predetermined electronic circuit from an electronic parts maker, specifications for the predetermined electronic circuit to the electronic parts maker, the electronic parts maker calculates the electrical characteristics of the predetermined electronic part on the basis of the specifications for the predetermined electronic circuit which are provided from the user, and presents to the user the types of electronic part which are adaptable to the calculated electrical characteristics, and the user selects the desirable type from the types of electronic part which are presented by the electronic parts maker.
    Type: Grant
    Filed: September 17, 2001
    Date of Patent: June 10, 2008
    Assignees: Sanyo Electric Co., Ltd., Saga Sanyo Industries Co., Ltd.
    Inventors: Seiya Kitagawa, Satoshi Aikawa
  • Publication number: 20080033837
    Abstract: A user provides, in purchasing a predetermined electronic part used for a predetermined electronic circuit from an electronic parts maker, specifications for the predetermined electronic circuit to the electronic parts maker, the electronic parts maker calculates the electrical characteristics of the predetermined electronic part on the basis of the specifications for the predetermined electronic circuit which are provided from the user, and presents to the user the types of electronic part which are adaptable to the calculated electrical characteristics, and the user selects the desirable type from the types of electronic part which are presented by the electronic parts maker.
    Type: Application
    Filed: September 28, 2007
    Publication date: February 7, 2008
    Applicants: Sanyo Electric Co., Ltd., Saga Sanyo Industries Co., Ltd.
    Inventors: Seiya Kitagawa, Satoshi Aikawa
  • Patent number: 7129682
    Abstract: A direct-current to direct-current conversion (DC/DC) apparatus includes a control circuit having an error amplifier for voltage control, basing the conversion on a pulse width modulation control using an output of the error amplifier. The error amplifier inputs a voltage signal corresponding to an output voltage of a DC/DC result and a plurality of reference voltage signals. The DC/DC apparatus also includes a soft start capacitor to provide one of the plurality of reference voltage signals. The error amplifier amplifies a difference between the voltage signal corresponding of the output voltage of a DC/DC result and a voltage signal of a lower potential among the plurality of reference voltage signals and carries out the pulse width modulation control. Furthermore, the control circuit includes a circuit for discharging charges corresponding to the output voltage of the DC/DC result when a power supply to the control circuit is turned off.
    Type: Grant
    Filed: May 23, 2005
    Date of Patent: October 31, 2006
    Assignee: Fujitsu Limited
    Inventors: Mitsuo Saeki, Hidetoshi Yano, Hidekiyo Ozawa, Seiya Kitagawa, Toshiyuki Matsuyama, Takashi Matsumoto, Kyuichi Takimoto, Yoshiaki Sano
  • Publication number: 20050264270
    Abstract: A direct-current to direct-current conversion (DC/DC) apparatus includes a control circuit having an error amplifier for voltage control, basing the conversion on a pulse width modulation control using an output of the error amplifier. The error amplifier inputs a voltage signal corresponding to an output voltage of a DC/DC result and a plurality of reference voltage signals. The DC/DC apparatus also includes a soft start capacitor to provide one of the plurality of reference voltage signals. The error amplifier amplifies a difference between the voltage signal corresponding of the output voltage of a DC/DC result and a voltage signal of a lower potential among the plurality of reference voltage signals and carries out the pulse width modulation control. Furthermore, the control circuit includes a circuit for discharging charges corresponding to the output voltage of the DC/DC result when a power supply to the control circuit is turned off.
    Type: Application
    Filed: May 23, 2005
    Publication date: December 1, 2005
    Applicant: FIJITSU LIMITED
    Inventors: Mitsuo Saeki, Hidetoshi Yano, Hidekiyo Ozawa, Seiya Kitagawa, Toshiyuki Matsuyama, Takashi Matsumoto, Kyuichi Takimoto, Yoshiaki Sano
  • Patent number: 6911806
    Abstract: A direct-current to direct-current conversion (DC/DC) apparatus includes a control circuit having an error amplifier for voltage control, basing the conversion on a pulse width modulation control using an output of the error amplifier. The error amplifier inputs a voltage signal corresponding to an output voltage of a DC/DC result and a plurality of reference voltage signals. The DC/DC apparatus also includes a soft start capacitor to provide one of the plurality of reference voltage signals. The error amplifier amplifies a difference between the voltage signal corresponding to the output voltage of a DC/DC result and a voltage signal of a lower potential among the plurality of reference voltage signals and carries out the pulse width modulation control. Furthermore, the control circuit includes a circuit for discharging charges corresponding to the output voltage of the DC/DC result when a power supply to the control circuit is turned off.
    Type: Grant
    Filed: December 15, 2003
    Date of Patent: June 28, 2005
    Assignee: Fujitsu Limited
    Inventors: Mitsuo Saeki, Hidetoshi Yano, Hidekiyo Ozawa, Seiya Kitagawa, Toshiyuki Matsuyama, Takashi Matsumoto, Kyuichi Takimoto, Yoshiaki Sano
  • Publication number: 20040135559
    Abstract: A direct-current to direct-current conversion (DC/DC) apparatus includes a control circuit having an error amplifier for voltage control and controlling a direct-current to direct-current conversion based on a pulse width modulation control using an output of the error amplifier. The error amplifier inputs a voltage signal corresponding to an output voltage of a DC/DC result and a plurality of reference voltage signals. The DC/DC apparatus also includes a soft start capacitor to provide one of the plurality of reference voltage signals. The error amplifier amplifies a difference between the voltage signal corresponding to the output voltage of a DC/DC result and a voltage signal of a lower potential among the plurality of reference voltage signals and, based on the amplified output, carries out the pulse width modulation control.
    Type: Application
    Filed: December 15, 2003
    Publication date: July 15, 2004
    Applicant: FUJITSU LIMITED
    Inventors: Mitsuo Saeki, Hidetoshi Yano, Hidekiyo Ozawa, Seiya Kitagawa, Toshiyuki Matsuyama, Takashi Matsmoto, Kyuichi Takimoto, Yoshiaki Sano
  • Patent number: 6707271
    Abstract: The present invention provides a battery charging/discharging method for effectively using the battery energy of a power supply apparatus with a plurality of chargeable batteries. The power supply apparatus in which batteries are connected in parallel to the node of an external power source and a load comprises a charge/discharge monitor unit for judging whether the external power source is in a state where a load is driven and sufficient voltage to charge the batteries is outputted or in a state where sufficient voltage is not outputted and a discharge current should be supplied from the batteries to the load, switches inserted in series with each of the batteries, and an on/off control unit for controlling the on/off operation of the switches according to the output of the charge/discharge monitor unit and the charging/discharging state of each battery.
    Type: Grant
    Filed: July 11, 2002
    Date of Patent: March 16, 2004
    Assignee: Fujitsu Limited
    Inventor: Seiya Kitagawa
  • Patent number: 6664772
    Abstract: A direct-current to direct-current conversion (DC/DC) apparatus includes a control circuit having an error amplifier for voltage control and controlling a direct-current to direct-current conversion based on a pulse width modulation control using an output of the error amplifier. The error amplifier inputs a voltage signal corresponding to an output voltage of a DC/DC result and a plurality of reference voltage signals. The DC/DC apparatus also includes a soft start capacitor to provide one of the plurality of reference voltage signals. The error amplifier amplifies a difference between the voltage signal corresponding to the output voltage of a DC/DC result and a voltage signal of a lower potential among the plurality of reference voltage signals and, based on-the amplified output, carries out the pulse width modulation control.
    Type: Grant
    Filed: May 21, 2001
    Date of Patent: December 16, 2003
    Assignee: Fujitsu Limited
    Inventors: Mitsuo Saeki, Hidetoshi Yano, Hidekiyo Ozawa, Seiya Kitagawa, Toshiyuki Matsuyama, Takashi Matsumoto, Kyuichi Takimoto, Yoshiaki Sano
  • Patent number: 6624613
    Abstract: The present invention provides a battery charging/discharging method for effectively using the battery energy of a power supply apparatus with a plurality of chargeable batteries. The power supply apparatus in which batteries are connected in parallel to the node of an external power source and a load comprises a charge/discharge monitor unit for judging whether the external power source is in a state where a load is driven and sufficient voltage to charge the batteries is outputted or in a state where sufficient voltage is not outputted and a discharge current should be supplied from the batteries to the load, switches inserted in series with each of the batteries, and an on/off control unit for controlling the on/off operation of the switches according to the output of the charge/discharge monitor unit and the charging/discharging state of each battery.
    Type: Grant
    Filed: January 11, 2002
    Date of Patent: September 23, 2003
    Assignee: Fujitsu Limited
    Inventor: Seiya Kitagawa
  • Publication number: 20030107355
    Abstract: A direct-current to direct-current conversion (DC/DC) apparatus includes a control circuit having an error amplifier for voltage control and controlling a direct-current to direct-current conversion based on a pulse width modulation control using an output of the error amplifier. The error amplifier inputs a voltage signal corresponding to an output voltage of a DC/DC result and a plurality of reference voltage signals. The DC/DC apparatus also includes a soft start capacitor to provide one of the plurality of reference voltage signals. The error amplifier amplifies a difference between the voltage signal corresponding to the output voltage of a DC/DC result and a voltage signal of a lower potential among the plurality of reference voltage signals and, based on the amplified output, carries out the pulse width modulation control.
    Type: Application
    Filed: May 21, 2001
    Publication date: June 12, 2003
    Applicant: Fujitsu LimitedFujitsu Limited
    Inventors: Mitsuo Saeki, Hidetoshi Yano, Hidekiyo Ozawa, Seiya Kitagawa, Toshiyuki Matsuyama, Takashi Matsumoto, Kyuichi Takimoto, Yoshiaki Sano
  • Publication number: 20020171399
    Abstract: The present invention provides a battery charging/discharging method for effectively using the battery energy of a power supply apparatus with a plurality of chargeable batteries. The power supply apparatus in which batteries are connected in parallel to the node of an external power source and a load comprises a charge/discharge monitor unit for judging whether the external power source is in a state where a load is driven and sufficient voltage to charge the batteries is outputted or in a state where sufficient voltage is not outputted and a discharge current should be supplied from the batteries to the load, switches inserted in series with each of the batteries, and an on/off control unit for controlling the on/off operation of the switches according to the output of the charge/discharge monitor unit and the charging/discharging state of each battery.
    Type: Application
    Filed: July 11, 2002
    Publication date: November 21, 2002
    Applicant: FUJITSU, LIMITED
    Inventor: Seiya Kitagawa
  • Patent number: 6452364
    Abstract: A battery charge control circuit, a battery charging device, and a battery charge control method for controlling the charging of a battery are provided. A power source supplies a current to a load, and a battery also supplies a current to the load. If the current supply capacity of the power source is restricted when the power source charges the battery, the charging of the battery is not stopped. Thus, a wrong operation can be avoided, and more reliable battery charging can be performed.
    Type: Grant
    Filed: March 22, 2000
    Date of Patent: September 17, 2002
    Assignee: Fujitsu Limited
    Inventors: Mitsuo Saeki, Seiya Kitagawa, Hidekiyo Ozawa, Toshiyuki Matsuyama
  • Patent number: 6445164
    Abstract: The present invention provides a battery charging/discharging method for effectively using the battery energy of a power supply apparatus with a plurality of chargeable batteries. The power supply apparatus in which batteries are connected in parallel to the node of an external power source and a load comprises a charge/discharge monitor unit for judging whether the external power source is in a state where a load is driven and sufficient voltage to charge the batteries is outputted or in a state where sufficient voltage is not outputted and a discharge current should be supplied from the batteries to the load, switches inserted in series with each of the batteries, and an on/off control unit for controlling the on/off operation of the switches according to the output of the charge/discharge monitor unit and the charging/discharging state of each battery.
    Type: Grant
    Filed: January 18, 2001
    Date of Patent: September 3, 2002
    Assignee: Fujitsu Limited
    Inventor: Seiya Kitagawa
  • Patent number: 6420858
    Abstract: A DC-to-DC converter circuit having a power saving mode, and which achieves a high conversion efficiency without using a sense resistance. The DC-to-DC converter circuit includes a triangular wave generation circuit to generate a triangular wave signal and a differential amplifier to receive the triangular wave signal and to generate an output signal. A main switching element is provided to turn ON and OFF an input voltage, and a synchronous commutating switching element is provided to perform synchronous commutation of a load current. A detection device detects whether an output voltage of the main switching element is larger than an input voltage of the main switching element. A control device operates in a power saving mode to reduce a drive voltage of the main switching element in response to the detection device detecting that the output voltage of the main switching element is larger than the input voltage.
    Type: Grant
    Filed: December 21, 1999
    Date of Patent: July 16, 2002
    Assignee: Fujitsu Limited
    Inventors: Seiya Kitagawa, Toshiyuki Matsuyama, Hidekiyo Ozawa