Patents by Inventor Takeshi Oumaru

Takeshi Oumaru 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: 7242113
    Abstract: A power semiconductor device which makes a heat come hard to arise in a particular element and is able to control an increase of the amount of a power loss caused by a tail current, even in case that plural power semiconductor elements are connected in parallel is provided. A control part (CTa) performs a regional control instead of a general control that all of IGBT elements (PD1 to PD4) are made to operate identically with providing a PWM signal (S0) for all of the elements. In other words, when a certain pulse in a pulse row of the PWM signal (S0) is inputted, only a part of switches (SW1 and SW2) is turned on and only a part of the IGBT elements (PD1 and PD2) is made to operate, and when a next pulse is inputted, only the other part of switches (SW3 and SW4) is turned on and only the other part of IGBT elements (PD3 and PD4) is made to operate. Moreover, the operation described above is repeated.
    Type: Grant
    Filed: October 17, 2003
    Date of Patent: July 10, 2007
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Takeshi Oumaru, Noboru Miyamoto
  • Patent number: 7084590
    Abstract: A voltage sensor (101) is connected to output terminals (P, N) of a booster. The voltage sensor (101) detects a boosted voltage, and outputs the detected voltage to a first drive controller (102). The first drive controller (102) outputs a control signal to a variable resistor (22) indicating a gate resistance obtained on the basis of the boosted voltage. The variable resistor (22) is controlled to have the specified gate resistance in response to the received control signal.
    Type: Grant
    Filed: May 25, 2004
    Date of Patent: August 1, 2006
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Noboru Miyamoto, Takeshi Oumaru
  • Publication number: 20050146295
    Abstract: A voltage sensor (101) is connected to output terminals (P, N) of a booster. The voltage sensor (101) detects a boosted voltage, and outputs the detected voltage to a first drive controller (102). The first drive controller (102) outputs a control signal to a variable resistor (22) indicating a gate resistance obtained on the basis of the boosted voltage. The variable resistor (22) is controlled to have the specified gate resistance in response to the received control signal.
    Type: Application
    Filed: May 25, 2004
    Publication date: July 7, 2005
    Applicant: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Noboru Miyamoto, Takeshi Oumaru
  • Publication number: 20040252430
    Abstract: A power semiconductor device which makes a heat come hard to arise in a particular element and is able to control an increase of the amount of a power loss caused by a tail current, even in case that plural power semiconductor elements are connected in parallel is provided.
    Type: Application
    Filed: October 17, 2003
    Publication date: December 16, 2004
    Applicant: MITSUBISHI DENKI KABUSHIKI KAISHA
    Inventors: Takeshi Oumaru, Noboru Miyamoto
  • Patent number: 6800934
    Abstract: A power module having a plurality of power devices arranged in parallel with each other and switched by gate signals with substantially equal electric potential. The power module includes: a collector electrode pattern, first and second power devices provided on the collector electrode pattern and each having a collector electrode connected to the collector electrode pattern; an emitter electrode pattern provided along the collector electrode pattern and having an emitter lead, and first and second connection means for connecting emitter electrodes on the first and second power devices and the emitter electrode pattern, respectively. The power module is characterized in that an inductance component of at least one of the first and second connection means is adjusted so that the inductance component between the emitter electrode on the first power device and the emitter lead is substantially equal to that between the emitter electrode on the second power device and the emitter lead.
    Type: Grant
    Filed: July 8, 2002
    Date of Patent: October 5, 2004
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Takeshi Oumaru
  • Publication number: 20030030481
    Abstract: A power module having a plurality of power devices arranged in parallel with each other and switched by gate signals with substantially equal electric potential. The power module includes: a collector electrode pattern, first and second power devices provided on the collector electrode pattern and each having a collector electrode connected to the collector electrode pattern; an emitter electrode pattern provided along the collector electrode pattern and having an emitter lead, and first and second connection means for connecting emitter electrodes on the first and second power devices and the emitter electrode pattern, respectively. The power module is characterized in that an inductance component of at least one of the first and second connection means is adjusted so that the inductance component between the emitter electrode on the first power device and the emitter lead is substantially equal to that between the emitter electrode on the second power device and the emitter lead.
    Type: Application
    Filed: July 8, 2002
    Publication date: February 13, 2003
    Applicant: MITSUBISHI DENKI KABUSHIKI KAISHA
    Inventor: Takeshi Oumaru