Patents by Inventor Shigeru Hasegawa

Shigeru Hasegawa 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).

  • Method of operating thyristor with insulated gates
    Patent number: 5428228
    Abstract: A thyristor with insulated gates includes turn-off and turn-on MOSFETs. The turn-on MOSFET has a turn-on gate employing a p-type base as a channel and extending over an n-type base and an n-type emitter. The turn-off MOSFET has n-type drain and source layers formed in a p-type base layer, and a turn-off gate extending over the drain and source layers. The n-type drain layer is short-circuited with the p-type base layer via a drain electrode. The drain electrode is formed near an n-type emitter layer. When the thyristor is to be turned off, the first voltage is applied to the turn-on gate, and the second voltage is applied to the turn-off gate while the first voltage is applied to the turn-on gate. After the application of the second voltage continues for a predetermined period of time, the application of the first voltage to the turn-on gate is stopped. With this operation, the thyristor can be turned off even with a large current.
    Type: Grant
    Filed: December 10, 1993
    Date of Patent: June 27, 1995
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tsuneo Ogura, Kiminori Watanabe, Akio Nakagawa, Yoshihiro Yamaguchi, Norio Yasuhara, Tomoko Matsudai, Shigeru Hasegawa, Kazuya Nakayama
  • Synchronization controller for electric machines
    Patent number: D337753
    Type: Grant
    Filed: September 12, 1991
    Date of Patent: July 27, 1993
    Assignee: Teac Corporation
    Inventors: Masafumi Ito, Shigeru Hasegawa, Katsuhiro Takashima, Keiji Tsunoda
  • Air cleaner
    Patent number: D338520
    Type: Grant
    Filed: April 13, 1992
    Date of Patent: August 17, 1993
    Assignee: TEAC Corporation
    Inventors: Masafumi Ito, Shigeru Hasegawa, Katsuhiro Takashima, Keiji Tsunoda
  • Streaming cassette tape drive
    Patent number: D338671
    Type: Grant
    Filed: August 10, 1990
    Date of Patent: August 24, 1993
    Assignee: TEAC Corporation
    Inventors: Masafumi Ito, Shigeru Hasegawa, Minoru Sube, Haruki Takita, Hiroyuki Watanabe, Keiji Tsunoda
  • Data recording/reproducing apparatus
    Patent number: D339585
    Type: Grant
    Filed: February 19, 1991
    Date of Patent: September 21, 1993
    Assignee: Teac Corporation
    Inventors: Masafumi Ito, Shigeru Hasegawa, Katsuhiro Takashima
  • Data recording/reproducing apparatus
    Patent number: D339586
    Type: Grant
    Filed: April 11, 1991
    Date of Patent: September 21, 1993
    Assignee: TEAC Corporation
    Inventors: Masafumi Ito, Shigeru Hasegawa
  • Digital audio disc player
    Patent number: D340716
    Type: Grant
    Filed: November 7, 1991
    Date of Patent: October 26, 1993
    Assignee: TEAC Corporation
    Inventors: Masafumi Ito, Shigeru Hasegawa, Keiji Tsunoda
  • Audio mixer
    Patent number: D340931
    Type: Grant
    Filed: December 30, 1991
    Date of Patent: November 2, 1993
    Assignee: Teac Corporation
    Inventors: Masafumi Ito, Shigeru Hasegawa
  • Knob for electric apparatus
    Patent number: D343348
    Type: Grant
    Filed: September 11, 1992
    Date of Patent: January 18, 1994
    Assignee: TEAC Corporation
    Inventors: Masafumi Ito, Shigeru Hasegawa
  • Data recorder/reproducer
    Patent number: D345563
    Type: Grant
    Filed: October 7, 1992
    Date of Patent: March 29, 1994
    Assignee: TEAC Corporation
    Inventors: Masafumi Ito, Shigeru Hasegawa, Katsuhiro Takashima
  • Digital audio tape recorder
    Patent number: D345735
    Type: Grant
    Filed: August 5, 1992
    Date of Patent: April 5, 1994
    Assignee: TEAC Corporation
    Inventors: Masafumi Ito, Shigeru Hasegawa, Katsuhiro Takashima
  • Digital audio tape recorder
    Patent number: D347223
    Type: Grant
    Filed: June 30, 1992
    Date of Patent: May 24, 1994
    Assignee: TEAC Corporation
    Inventors: Masafumi Ito, Shigeru Hasegawa, Katsuhiro Takashima
  • Combined data recorder and reproducer
    Patent number: D348446
    Type: Grant
    Filed: November 18, 1992
    Date of Patent: July 5, 1994
    Assignee: TEAC Corporation
    Inventors: Masafumi Ito, Koji Suzuki, Shigeru Hasegawa, Katsuhiro Takashima
  • Audio mixer
    Patent number: D349705
    Type: Grant
    Filed: April 9, 1990
    Date of Patent: August 16, 1994
    Assignee: Teac Corporation
    Inventors: Masafumi Ito, Koji Suzuki, Shigeru Hasegawa, Katsuhiro Takashima
  • Audio mixer
    Patent number: D349706
    Type: Grant
    Filed: February 27, 1992
    Date of Patent: August 16, 1994
    Assignee: Teac Corporation
    Inventors: Masafumi Ito, Shigeru Hasegawa
  • Combined audio mixer and tape recorder
    Patent number: D356311
    Type: Grant
    Filed: January 28, 1993
    Date of Patent: March 14, 1995
    Assignee: Teac Corporation
    Inventors: Masafumi Ito, Shigeru Hasegawa, Katsuhiro Takashima, Yasunobu Shimizu
  • Audio mixer
    Patent number: D357255
    Type: Grant
    Filed: December 3, 1993
    Date of Patent: April 11, 1995
    Assignee: Teac Corporation
    Inventors: Masafumi Ito, Koji Suzuki, Shigeru Hasegawa
  • Remote controller for a disc recording/reproducing unit
    Patent number: D357917
    Type: Grant
    Filed: June 8, 1993
    Date of Patent: May 2, 1995
    Assignee: TEAC Corporation
    Inventors: Masafumi Ito, Shigeru Hasegawa, Katsuhiro Takashima, Tooru Katayama
  • Remote controller for video tape recorder
    Patent number: D358152
    Type: Grant
    Filed: December 1, 1993
    Date of Patent: May 9, 1995
    Assignee: Teac Corporation
    Inventors: Masafumi Ito, Shigeru Hasegawa, Katsuhiro Takashima, Yasunobu Shimizu
  • Disc drive
    Patent number: D358378
    Type: Grant
    Filed: April 21, 1993
    Date of Patent: May 16, 1995
    Assignee: Teac Corporation
    Inventors: Masafumi Ito, Shigeru Hasegawa, Katsuhiro Takashima