Patents by Inventor Kazunori Oyabe

Kazunori Oyabe 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: 7773400
    Abstract: A phase adjusting circuit is provided that is capable of adjusting a delay time at a rise or fall of a driving signal for driving an inverter. A phase adjusting circuit is provided upstream of a driver circuit, and an output from a hysteresis comparator is input to the driver circuit through the phase adjusting circuit. The phase adjusting circuit delays at least either rise or fall of the signal input to the driver circuit to adjust any difference between the pulse width of the input signal input to the driver circuit and the pulse width of a signal output from a switching element of an inverter driven by the driver circuit.
    Type: Grant
    Filed: August 27, 2007
    Date of Patent: August 10, 2010
    Assignee: Fuji Electric Systems Co., Ltd.
    Inventors: Akira Nakamori, Kazunori Oyabe, Manabu Watanabe
  • Patent number: 7592853
    Abstract: A drive circuit for an insulated gate device includes a constant current source generating a constant current, and a switching circuit, wherein a gate of the insulated gate device is connected to a power supply potential side via the constant current source at the time of turn-on and to a ground potential side at the time of turn-off. Whereby a drive circuit for the insulated gate device can be reduced loss at the time of turn-on and reduced temperature dependency of noise.
    Type: Grant
    Filed: August 30, 2007
    Date of Patent: September 22, 2009
    Assignee: Fuji Electric Device Technology Co., Ltd
    Inventors: Akira Nakamori, Kazunori Oyabe
  • Patent number: 7507023
    Abstract: A temperature measurement device of a power semiconductor device includes a plurality of temperature detecting diodes formed on a first chip having a power semiconductor device; and a detection circuit that is formed on a second chip having an integrated circuit that controls the power semiconductor device and is connected to the temperature detecting diodes; wherein the detection circuit detects a temperature of the power semiconductor device based on a difference between the forward voltages of the temperature detecting diodes when different values of current flow to the respective temperature detecting diodes.
    Type: Grant
    Filed: April 14, 2006
    Date of Patent: March 24, 2009
    Assignee: Fuji Electric Device Technology Co., Ltd.
    Inventors: Kazunori Oyabe, Tomoyuki Yamazaki, Yasushi Miyasaka
  • Publication number: 20080094111
    Abstract: A drive circuit for an insulated gate device includes a constant current source generating a constant current, and a switching circuit, wherein a gate of the insulated gate device is connected to a power supply potential side via the constant current source at the time of turn-on and to a ground potential side at the time of turn-off. Whereby a drive circuit for the insulated gate device can be reduced loss at the time of turn-on and reduced temperature dependency of noise.
    Type: Application
    Filed: August 30, 2007
    Publication date: April 24, 2008
    Applicant: FUJI ELECTRIC DEVICE TECHNOLOGY CO., LTD.
    Inventors: Akira NAKAMORI, Kazunori OYABE
  • Publication number: 20080094121
    Abstract: A phase adjusting circuit is provided that is capable of adjusting a delay time at a rise or fall of a driving signal for driving an inverter. A phase adjusting circuit is provided upstream of a driver circuit, and an output from a hysteresis comparator is input to the driver circuit through the phase adjusting circuit. The phase adjusting circuit delays at least either rise or fall of the signal input to the driver circuit to adjust any difference between the pulse width of the input signal input to the driver circuit and the pulse width of a signal output from a switching element of an inverter driven by the driver circuit.
    Type: Application
    Filed: August 27, 2007
    Publication date: April 24, 2008
    Applicant: FUJI ELECTRIC DEVICE TECHNOLOGY CO., LTD.
    Inventors: Akira NAKAMORI, Kazunori OYABE, Manabu WATANABE
  • Publication number: 20060255361
    Abstract: A temperature measurement device of a power semiconductor device includes a plurality of temperature detecting diodes formed on a first chip having a power semiconductor device; and a detection circuit that is formed on a second chip having an integrated circuit that controls the power semiconductor device and is connected to the temperature detecting diodes; wherein the detection circuit detects a temperature of the power semiconductor device based on a difference between the forward voltages of the temperature detecting diodes when different values of current flow to the respective temperature detecting diodes.
    Type: Application
    Filed: April 14, 2006
    Publication date: November 16, 2006
    Inventors: Kazunori Oyabe, Tomoyuki Yamazaki, Yasushi Miyasaka
  • Patent number: 6934139
    Abstract: An intelligent power module includes semiconductor switching devices, drive circuits, a variety of detecting circuits and warning circuits for detecting a fatal abnormal condition and a precursory abnormal condition thereof in the switching devices, the drive circuits and so forth, abnormal condition detecting logic devices and drive circuits for protecting the switching devices when the detecting circuits and the warning circuits detect the abnormal condition, and control circuits and a transmission circuit for outputting a signal based on detection of the abnormal condition. The transmission circuit has an output terminal for outputting alarm signals when the fatal abnormal condition is detected, and an output terminal for outputting abnormality factor discrimination signals indicating abnormality factors contributing to the fatal abnormal condition and the precursory abnormal condition.
    Type: Grant
    Filed: May 1, 2001
    Date of Patent: August 23, 2005
    Assignee: Fuji Electric Device Technology Co., Ltd.
    Inventors: Naoki Kumagai, Kazunori Oyabe, Naotaka Matsuda
  • Patent number: 6404659
    Abstract: When an alarm signal provided by an inverter forming an I/F provided for the circuit on the high side enters an active (L) state, the output of the inverter indicates an H state. Then, the N-channel MOS type FET enters an ON state. At this time, the N-channel MOS type FET is connected to the I/F on the low side using a diode. Therefore, when the diode enters a normal bias state, that is, when the reference potential of the above mentioned two I/Fs approach each other, an electric current flows from the power supply to the N-channel MOS type FET through a resistor. As a result, by a voltage drop, a voltage arises in the resistor, and the output of the inverter indicates the H state. Since the output of the inverter is connected to a control unit, the control unit performs a process according to an alarm signal.
    Type: Grant
    Filed: October 19, 2000
    Date of Patent: June 11, 2002
    Assignee: Fuji Electric Co., Ltd.
    Inventor: Kazunori Oyabe
  • Publication number: 20020039269
    Abstract: An intelligent power module includes semiconductor switching devices, drive circuits, a variety of detecting circuits and warning circuits for detecting a fatal abnormal condition and a precursory abnormal condition thereof in the switching devices, the drive circuits and so forth, abnormal condition detecting logic devices and drive circuits for protecting the switching devices when the detecting circuits and the warning circuits detect the abnormal condition, and control circuits and a transmission circuit for outputting a signal based on detection of the abnormal condition. The transmission circuit has an output terminal for outputting alarm signals when the fatal abnormal condition is detected, and an output terminal for outputting abnormality factor discrimination signals indicating abnormality factors contributing to the fatal abnormal condition and the precursory abnormal condition.
    Type: Application
    Filed: May 1, 2001
    Publication date: April 4, 2002
    Inventors: Naoki Kumagai, Kazunori Oyabe
  • Patent number: 5811996
    Abstract: A gate drive circuit device for a voltage-driven semiconductor element reduces the time to dissipate inductively stored electromagnetic energy and reduces current consumption by using cyclically charged capacitative storage to produce a control signal that is about twice the supply voltage. This permits full-ON dissipation of the stored energy after the circuit cuts off power to the inductive element. In one embodiment, the dissipation is chiefly in a voltage-regulator diode connected to limit the voltage appearing across a transistor. In another embodiment, a voltage regulator diode permits a transistor to operate in the full-on condition, while limiting the voltage across it to a value below its withstand voltage, whereby a maximum power dissipation current flows in the transistor. In a further embodiment a gate drive signal generator eliminates a voltage regulator diode from the conventional gate drive circuit device.
    Type: Grant
    Filed: December 17, 1996
    Date of Patent: September 22, 1998
    Assignee: Fuji Electric Co., Ltd.
    Inventors: Kazunori Oyabe, Tatsuhiko Fujihira, Kazuhiko Yoshida, Yukio Yano
  • Patent number: 5621601
    Abstract: The disclosed invention is designed to prevent the oscillation which often occurs in an over-current protection apparatus for an insulated gate controlled transistor. The apparatus improves the response in current detection, to prevent oscillation, and improves protection speed against over-current.
    Type: Grant
    Filed: September 28, 1994
    Date of Patent: April 15, 1997
    Assignee: Fuji Electric Co., Ltd.
    Inventors: Tatsuhiko Fujihira, Shin Kiuchi, Kazuhiko Yoshida, Yukio Yano, Kazunori Oyabe, Shoichi Furuhata, Tetsuhiro Morimoto
  • Patent number: 5587655
    Abstract: A constant current circuit of the invention supplies a constant current to a load. The constant current circuit is formed of a current source device for providing an input current having a predetermined value with temperature dependence, a voltage divider device connected to the current source device, and an output transistor device. A reference transistor device or an adjusting transistor device is attached to the current source device. In case the reference transistor device is used, the voltage divider device divides a reference voltage of the reference transistor device to thereby generate a control voltage. In case the adjusting transistor device is used, an adjusting voltage from the voltage divider device is supplied to the adjusting transistor device to generate a control voltage. The output transistor device is connected to the load for controlling an output current supplied to the load in response to the control voltage.
    Type: Grant
    Filed: August 11, 1995
    Date of Patent: December 24, 1996
    Assignee: Fuji Electric Co., Ltd.
    Inventors: Kazunori Oyabe, Kazuhiko Yoshida, Tatsuhiko Fujihira