Patents by Inventor Shoichi Okuda

Shoichi Okuda 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: 7453310
    Abstract: A switching circuit of the present invention can be advantageously used in an electronic control unit mounted on an automotive vehicle. The switching circuit is constituted by a pair of P-channel MOS-FETs connected in series between an input terminal and an output terminal. Sources of both MOS-FETs are connected to a common source junction and gates thereof are connected to a common gate junction. A Zener diode connected between the common source junction and the common gate junction is used for protecting the MOS-FETs. A resistor is connected in parallel to the Zener diode to bring the switching circuit to a non-conductive state when the gate voltage at the common gate junction becomes indefinite and a high voltage is supplied to the output terminal. In place of the resistor, an additional P-channel MOS-FET may be used in the switching circuit to bring the switching circuit to the non-conductive state when the voltage at the common gate junction becomes indefinite.
    Type: Grant
    Filed: August 8, 2006
    Date of Patent: November 18, 2008
    Assignee: DENSO CORPORATION
    Inventors: Kingo Ota, Shoichi Okuda
  • Patent number: 7268596
    Abstract: A semiconductor device for driving a load includes a first semiconductor switching element interposed between a power supply terminal and a load, a second semiconductor switching element interposed between the load and a ground terminal, a high-side driver, a low-side driver, and a voltage regulator. The voltage regulator reduces a voltage applied to a control terminal of the second switching element, when a voltage of a load terminal of the second switching element is lower than a predetermined voltage. Then, a voltage applied between the load terminal and the ground terminal of the second switching element increases, and accordingly a voltage applied between the power supply terminal and the load terminal of the first switching element decreases.
    Type: Grant
    Filed: September 8, 2005
    Date of Patent: September 11, 2007
    Assignee: DENSO CORPORATION
    Inventors: Kingo Ota, Shoichi Okuda, Hirofumi Abe
  • Publication number: 20070063747
    Abstract: A switching circuit of the present invention can be advantageously used in an electronic control unit mounted on an automotive vehicle. The switching circuit is constituted by a pair of P-channel MOS-FETs connected in series between an input terminal and an output terminal. Sources of both MOS-FETs are connected to a common source junction and gates thereof are connected to a common gate junction. A Zener diode connected between the common source junction and the common gate junction is used for protecting the MOS-FETs. A resistor is connected in parallel to the Zener diode to bring the switching circuit to a non-conductive state when the gate voltage at the common gate junction becomes indefinite and a high voltage is supplied to the output terminal. In place of the resistor, an additional P-channel MOS-FET may be used in the switching circuit to bring the switching circuit to the non-conductive state when the voltage at the common gate junction becomes indefinite.
    Type: Application
    Filed: August 8, 2006
    Publication date: March 22, 2007
    Applicant: DENSO CORPORATION
    Inventors: Kingo Ota, Shoichi Okuda
  • Publication number: 20060267147
    Abstract: A semiconductor device includes a semiconductor substrate and a current mirror circuit that has an input transistor group of input transistors and an output transistor group of output transistors. The input transistor group and the output transistor group are arranged on the semiconductor substrate in such a manner that at least one of the input transistors and at least one of the output transistors are grouped together to form a transistor set. Each transistor set is arranged in a repeating pattern. In each transistor set, the transistors have the same temperature and show the same temperature dependence, even when a temperature gradient occurs inside the semiconductor device. Thus, a mirror ratio of the current mirror circuit can be accurately obtained.
    Type: Application
    Filed: May 30, 2006
    Publication date: November 30, 2006
    Applicant: DENSO CORPORATION
    Inventors: Kingo Ota, Shoichi Okuda
  • Publication number: 20060087348
    Abstract: A semiconductor device for driving a load includes a first semiconductor switching element interposed between a power supply terminal and a load, a second semiconductor switching element interposed between the load and a ground terminal, a high-side driver, a low-side driver, and a voltage regulator. The voltage regulator reduces a voltage applied to a control terminal of the second switching element, when a voltage of a load terminal of the second switching element is lower than a predetermined voltage. Then, a voltage applied between the load terminal and the ground terminal of the second switching element increases, and accordingly a voltage applied between the power supply terminal and the load terminal of the first switching element decreases.
    Type: Application
    Filed: September 8, 2005
    Publication date: April 27, 2006
    Inventors: Kingo Ota, Shoichi Okuda, Hirofumi Abe
  • Patent number: 7034616
    Abstract: In a circuit according to the present invention, a multi-collector transistor is provided which includes first to third collectors so that, when a current does not flow from the second collector, a current from the first collector increases but a current from the third collector does not vary. When transistors of the circuit turn off because the voltage of an input signal gets out of an in-phase input voltage range, the supply of the current from the second collector comes to a stop and, hence, the current from the first collector increases. In this situation, further transistors carry out their on/off operations, thereby fixing the output of the circuit to a low level. That is, this circuit can, irrespective of poor pair compatibility between the transistors, fix the output logical level to a desired level when the voltage of an input signal gets out of an in-phase input voltage range.
    Type: Grant
    Filed: February 3, 2004
    Date of Patent: April 25, 2006
    Assignee: Denso Corporation
    Inventors: Naoya Tsuchiya, Hirofumi Abe, Shoichi Okuda
  • Patent number: 6972973
    Abstract: In a voltage booster, a voltage detection circuit detects a battery voltage as an input voltage. If the input voltage is lower than a threshold level, an oscillation circuit outputs a gate signal having a relatively high frequency to increase the driving performance of a driving circuit. If the input voltage is higher than the threshold level, the frequency of the gate signal is lowered so as to prevent the driving performance of the driving circuit from rising to an excessively high value. As a result, a predetermined boosted voltage can be obtained regardless of variations in input voltage without using a filter for eliminating noise.
    Type: Grant
    Filed: November 20, 2003
    Date of Patent: December 6, 2005
    Assignee: Denso Corporation
    Inventors: Hirofumi Abe, Hirokazu Itakura, Hiroyuki Ban, Shoichi Okuda, Kingo Ota
  • Patent number: 6954058
    Abstract: In a current mirror circuit, a compensation resistor having a positive temperature coefficient is connected between the source of a MOS transistor and a power supply line. When the temperature rises, a current output by the constant current circuit and a current flowing through the drain of the MOS transistor decrease. Since the resistance of the compensation resistor increases, however, a voltage between the gate and source of another MOS transistor can be prevented from declining due to the decrease in the drain current so that an electric potential at the gate of a further MOS transistor, hence, a main current, can be prevented from fluctuating. In addition, a constant current output circuit is configured to shunt a feedback control current thereby to adjust an output current of each channel.
    Type: Grant
    Filed: March 9, 2004
    Date of Patent: October 11, 2005
    Assignee: Denso Corporation
    Inventors: Kingo Ota, Shoichi Okuda
  • Patent number: 6891708
    Abstract: A drive circuit for driving a switching element is provided which includes a high-side switching circuit connected between power supply lines, a low-side switching circuit connected in series with the high-side switching circuit through an output terminal leading to the switching element, and a voltage detector detecting a voltage appearing at the output terminal. When the voltage detected by the voltage detector is lower than a given off-decision voltage, that is, when the switching element is placed in the off-state, the low-side switching circuit is brought into the off-state, thereby reducing the current consumption thereof.
    Type: Grant
    Filed: September 4, 2001
    Date of Patent: May 10, 2005
    Assignee: Denso Corporation
    Inventors: Takaharu Hutamura, Shoichi Okuda
  • Publication number: 20040183515
    Abstract: In a current mirror circuit, a compensation resistor having a positive temperature coefficient is connected between the source of a MOS transistor and a power supply line. When the temperature rises, a current output by the constant current circuit and a current flowing through the drain of the MOS transistor decrease. Since the resistance of the compensation resistor increases, however, a voltage between the gate and source of another MOS transistor can be prevented from declining due to the decrease in the drain current so that an electric potential at the gate of a further MOS transistor, hence, a main current, can be prevented from fluctuating. In addition, a constant current output circuit is configured to shunt a feedback control current thereby to adjust an output current of each channel.
    Type: Application
    Filed: March 9, 2004
    Publication date: September 23, 2004
    Applicant: DENSO CORPORATION
    Inventors: Kingo Ota, Shoichi Okuda
  • Publication number: 20040155709
    Abstract: In a circuit according to the present invention, a multi-collector transistor is provided which includes first to third collectors so that, when a current does not flow from the second collector, a current from the first collector increases but a current from the third collector does not vary. When transistors of the circuit turn off because the voltage of an input signal gets out of an in-phase input voltage range, the supply of the current from the second collector comes to a stop and, hence, the current from the first collector increases. In this situation, further transistors carry out their on/off operations, thereby fixing the output of the circuit to a low level. That is, this circuit can, irrespective of poor pair compatibility between the transistors, fix the output logical level to a desired level when the voltage of an input signal gets out of an in-phase input voltage range.
    Type: Application
    Filed: February 3, 2004
    Publication date: August 12, 2004
    Inventors: Naoya Tsuchiya, Hirofumi Abe, Shoichi Okuda
  • Publication number: 20040136212
    Abstract: In a voltage booster, a voltage detection circuit detects a battery voltage as an input voltage. If the input voltage is lower than a threshold level, an oscillation circuit outputs a gate signal having a relatively high frequency to increase the driving performance of a driving circuit. If the input voltage is higher than the threshold level, the frequency of the gate signal is lowered so as to prevent the driving performance of the driving circuit from rising to an excessively high value. As a result, a predetermined boosted voltage can be obtained regardless of variations in input voltage without using a filter for eliminating noise.
    Type: Application
    Filed: November 20, 2003
    Publication date: July 15, 2004
    Inventors: Hirofumi Abe, Hirokazu Itakura, Hiroyuki Ban, Shoichi Okuda, Kingo Ota
  • Publication number: 20020027391
    Abstract: A drive circuit for driving a switching element is provided which includes a high-side switching circuit connected between power supply lines, a low-side switching circuit connected in series with the high-side switching circuit through an output terminal leading to the switching element, and a voltage detector detecting a voltage appearing at the output terminal. When the voltage detected by the voltage detector is lower than a given off-decision voltage, that is, when the switching element is placed in the off-state, the low-side switching circuit is brought into the off-state, thereby reducing the current consumption thereof.
    Type: Application
    Filed: September 4, 2001
    Publication date: March 7, 2002
    Inventors: Takaharu Hutamura, Shoichi Okuda
  • Patent number: 6081040
    Abstract: An alignment mark for determining a position of a thin film resistor formed on a semiconductor chip. The alignment mark is disposed on a capacitor formation region of the semiconductor chip. Because aluminum wiring members of the semiconductor chip are not disposed adjacent to the alignment mark within the capacitor formation region, the alignment mark can be precisely recognized. As a result, the position of the thin film resistor can be also precisely determined.
    Type: Grant
    Filed: March 16, 1998
    Date of Patent: June 27, 2000
    Assignee: Denso Corporation
    Inventors: Shoichi Okuda, Mitsuhiro Saitou, Hiroyuki Ban
  • Patent number: 5977651
    Abstract: A drive circuit for a vehicle occupant safety apparatus includes a device for activating the vehicle occupant safety apparatus. A first transistor is connected in series with the device. A constant-current circuit receives electric energy from a power supply, and feeds a constant current to the device when the first transistor falls into its on state. The constant-current circuit includes a second transistor connected in series with the device. The second transistor includes an N-channel field-effect transistor. A third transistor is connected to the second transistor. The second and third transistors form a current mirror circuit. The third transistor includes an N-channel field-effect transistor. A voltage between a gate and a source of the third transistor is regulated at a constant level. Gate voltages of the second and third transistors are controlled in response to source voltages of the second and third transistors to equalize the source voltages of the second and third transistors.
    Type: Grant
    Filed: October 31, 1997
    Date of Patent: November 2, 1999
    Assignee: Denso Corporation
    Inventors: Nobumasa Ueda, Nobuo Mayumi, Mitsuhiro Saitou, Shoichi Okuda