Patents by Inventor Tooru ASAKAWA

Tooru ASAKAWA 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: 10365679
    Abstract: A regenerative current detection circuit includes a first power MOS transistor that is configured as a current mirror to a second power MOS transistor connected to drive a motor winding, a first feedback amplifier that compares a first regenerative current that flows in the first power MOS transistor with a second regenerative current that flows in the second power MOS transistor and outputs a comparison result, the first regenerative current being obtained by multiplying the second regenerative current by a current mirror ratio, and a current detection circuit that outputs a detection current based on the comparison result.
    Type: Grant
    Filed: August 29, 2017
    Date of Patent: July 30, 2019
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Daisuke Arai, Tooru Asakawa, Masahiro Shimozono, Katsumi Shiokawa
  • Publication number: 20180196457
    Abstract: A regenerative current detection circuit includes a first power MOS transistor that is configured as a current mirror to a second power MOS transistor connected to drive a motor winding, a first feedback amplifier that compares a first regenerative current that flows in the first power MOS transistor with a second regenerative current that flows in the second power MOS transistor and outputs a comparison result, the first regenerative current being obtained by multiplying the second regenerative current by a current mirror ratio, and a current detection circuit that outputs a detection current based on the comparison result.
    Type: Application
    Filed: August 29, 2017
    Publication date: July 12, 2018
    Inventors: Daisuke ARAI, Tooru ASAKAWA, Masahiro SHIMOZONO, Katsumi SHIOKAWA
  • Patent number: 9595898
    Abstract: According to one embodiment, a device for controlling motor driving which includes a first comparator, a second comparator, a zero level detecting portion, and a data determining portion is provided. The first comparator compares a voltage induced in a coil with a first threshold value. The second comparator compares the induced voltage with a second threshold value which is different from the first threshold value. The zero level detecting portion detects that a current flowing in an H-bridge circuit is zero. The data determining portion determines a value of digital data to be inputted to a DA convertor which generates a reference voltage for use in controlling a driving current of the motor based on an output of the first comparator, an output of the second comparator and an output of the zero level detecting portion.
    Type: Grant
    Filed: February 26, 2016
    Date of Patent: March 14, 2017
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kouji Inoue, Tooru Asakawa
  • Publication number: 20170054392
    Abstract: According to one embodiment, a device for controlling motor driving which includes a first comparator, a second comparator, a zero level detecting portion, and a data determining portion is provided. The first comparator compares a voltage induced in a coil with a first threshold value. The second comparator compares the induced voltage with a second threshold value which is different from the first threshold value. The zero level detecting portion detects that a current flowing in an H-bridge circuit is zero. The data determining portion determines a value of digital data to be inputted to a DA convertor which generates a reference voltage for use in controlling a driving current of the motor based on an output of the first comparator, an output of the second comparator and an output of the zero level detecting portion.
    Type: Application
    Filed: February 26, 2016
    Publication date: February 23, 2017
    Inventors: Kouji Inoue, Tooru Asakawa
  • Patent number: 9036312
    Abstract: A semiconductor device for protecting loads from power surges includes a first resistor having a first end connected to a first supply terminal, a capacitor connected to a second end of the first resistor and a second supply terminal. There is a first transistor with a source connected to the first supply terminal and a gate connected to a point between the first resistor and the capacitor. A second resistor is connected between the drain of the first transistor and the second supply terminal, and a first diode is connected between the gate and the source of the first transistor. A second transistor has a drain connected to the first supply terminal, a source connected to the second supply terminal, and a gate connected to the drain of the first transistor. There is a second diode connected between the gate and the source of the second transistor.
    Type: Grant
    Filed: March 1, 2013
    Date of Patent: May 19, 2015
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kazuhiro Kato, Hiroyuki Tsurumi, Yukio Sato, Takehito Ikimura, Akira Kumamoto, Hiroyuki Yamamoto, Shoichi Imakake, Tooru Asakawa
  • Publication number: 20130242449
    Abstract: A semiconductor device for protecting loads from power surges includes a first resistor having a first end connected to a first supply terminal, a capacitor connected to a second end of the first resistor and a second supply terminal. There is a first transistor with a source connected to the first supply terminal and a gate connected to a point between the first resistor and the capacitor. A second resistor is connected between the drain of the first transistor and the second supply terminal, and a first diode is connected between the gate and the source of the first transistor. A second transistor has a drain connected to the first supply terminal, a source connected to the second supply terminal, and a gate connected to the drain of the first transistor. There is a second diode connected between the gate and the source of the second transistor.
    Type: Application
    Filed: March 1, 2013
    Publication date: September 19, 2013
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Kazuhiro KATO, Hiroyuki TSURUMI, Yukio SATO, Takehito IKIMURA, Akira KUMAMOTO, Hiroyuki YAMAMOTO, Shoichi IMAKAKE, Tooru ASAKAWA