Patents by Inventor Akimasa Niwa

Akimasa Niwa 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).

  • Publication number: 20220376689
    Abstract: A signal detection circuit includes: a voltage dividing circuit having at least a first pair of voltage dividing capacitors connected in series for dividing an input voltage and configured to output a divided voltage, and a detection circuit configured to detect the divided voltage. The first pair of voltage dividing capacitors are included in one semiconductor device. The semiconductor device includes: (i) a semiconductor substrate, (ii) a first conductor layer, (iii) a first dielectric layer, (iv) a second conductor layer, (v) a second dielectric layer, (vi) a third conductor layer, and (vii) a short-circuit portion configured to short-circuit the first conductor layer and the semiconductor substrate.
    Type: Application
    Filed: May 18, 2022
    Publication date: November 24, 2022
    Inventors: MASAHIRO YAMAMOTO, AKIMASA NIWA
  • Publication number: 20220357410
    Abstract: A circuit for detecting a leakage current in a semiconductor element includes a setting circuit and a detector. The semiconductor element includes a first terminal at a high-potential-side of the semiconductor element, a second terminal at a low-potential-side of the semiconductor element, and a control terminal. The control terminal receives a signal for controlling a conduction state between the first terminal and the second terminal. The setting circuit sets a duration during which a charging current flows to the control terminal as an undetectable duration, in response to turning on the semiconductor element. The detector outputs a detected signal based on a condition that the leakage current flowing from the control terminal to the second terminal, after the undetectable duration has been elapsed.
    Type: Application
    Filed: April 29, 2022
    Publication date: November 10, 2022
    Inventors: JUNICHI HASEGAWA, AKIMASA NIWA
  • Patent number: 11431332
    Abstract: A gate drive circuit includes a driver for driving a gate of a switching element, a peak voltage detector, and a drive capacity calculator. The peak voltage detector detects a peak voltage at a main terminal of the switching element when the switching element is OFF. The drive capacity calculator calculates a voltage difference value between the detected peak voltage and an allowable voltage value at the main terminal of the switching element, where the allowable voltage is based on the specifications of the switching element. The drive capacity calculator changes a drive capacity of the driver to gradually decrease the difference between the detected peak voltage and the allowable voltage.
    Type: Grant
    Filed: October 16, 2020
    Date of Patent: August 30, 2022
    Assignee: DENSO CORPORATION
    Inventors: Masahiro Yamamoto, Akimasa Niwa
  • Publication number: 20220109438
    Abstract: A drive circuit drives a switch configuring a power converter. The drive circuit divides an inter-terminal voltage of a switch. The drive circuit includes a differential circuit having first and second input terminals to which the divided inter-terminal voltages are inputted. The differential circuit outputs an analog voltage based on a voltage difference between the input terminals. The differential circuit executes reset of the output voltage, and with the voltage difference when reset is canceled after reset is executed as a reference voltage, outputs an analog voltage in which an amount of change from the reference voltage is multiplied by an amplification factor. The drive circuit outputs a binary signal based on comparison results between a threshold and the analog voltage outputted from the differential circuit, and sets a transfer rate of a gate charge of the switch when a driving state is switched, based on the output signal thereof.
    Type: Application
    Filed: December 14, 2021
    Publication date: April 7, 2022
    Applicant: DENSO CORPORATION
    Inventors: Yuuta NAKAMURA, Yasuaki AOKI, Hideji YOSHIDA, Takashi YOSHIYA, Tomohiro NEZUKA, Akimasa NIWA
  • Publication number: 20220103061
    Abstract: In a drive circuit, a differential circuit unit is configured such that resetting of an output voltage of the differential circuit unit is carried out, and the resetting of the output voltage of the differential circuit unit is cancelled. A value of the difference between first and second divided terminal voltages at a timing of cancelling the resetting is defined as a reference voltage. The differential circuit unit generates, as the output voltage, a product of a voltage change from a reference voltage and a predetermined amplification factor after cancelling of the resetting of the differential circuit unit. A signal generator generates a gate signal for the upper- and lower-arm switches in accordance with a value of the output voltage of the differential circuit unit while the upper- and lower-arm switches are in an off state.
    Type: Application
    Filed: December 10, 2021
    Publication date: March 31, 2022
    Applicant: DENSO CORPORATION
    Inventors: Yasuaki AOKI, Tomohiro NEZUKA, Akimasa NIWA
  • Patent number: 11283438
    Abstract: A gate drive apparatus includes a driver, a peak voltage detector and a drive capability controller. The driver drives a gate of a first switching element as one of two switching elements respectively in an upper arm and a lower arm of a half-bridge circuit. The peak voltage detector detects a peak voltage at a second switching element in a situation where the first switching element is turned on. The drive capability controller calculates a value of drive capability when the driver turns on the first switching element, in a condition that the peak voltage at the second switching element does not exceed a tolerance value of a voltage at the second switching element according to a specification of the second switching element, and modifies the drive capability when the driver turns on the first switching element, based on a calculated result of the value of the drive capability.
    Type: Grant
    Filed: April 7, 2021
    Date of Patent: March 22, 2022
    Assignee: DENSO CORPORATION
    Inventors: Hironori Akiyama, Akimasa Niwa, Masahiro Yamamoto
  • Publication number: 20210258004
    Abstract: A gate drive apparatus includes a driver, a peak voltage detector and a drive capability controller. The driver drives a gate of a first switching element as one of two switching elements respectively in an upper arm and a lower arm of a half-bridge circuit. The peak voltage detector detects a peak voltage at a second switching element in a situation where the first switching element is turned on. The drive capability controller calculates a value of drive capability when the driver turns on the first switching element, in a condition that the peak voltage at the second switching element does not exceed a tolerance value of a voltage at the second switching element according to a specification of the second switching element, and modifies the drive capability when the driver turns on the first switching element, based on a calculated result of the value of the drive capability.
    Type: Application
    Filed: April 7, 2021
    Publication date: August 19, 2021
    Inventors: Hironori AKIYAMA, Akimasa NIWA, Masahiro YAMAMOTO
  • Patent number: 10979039
    Abstract: A gate drive circuit includes a driver for driving a gate of a switching element, a peak voltage detector, and a drive capacity calculator. The peak voltage detector detects a peak voltage at a main terminal of the switching element when the switching element is OFF. The drive capacity calculator calculates a voltage difference value between the detected peak voltage and an allowable voltage value at the main terminal of the switching element, where the allowable voltage is based on the specifications of the switching element. The drive capacity calculator changes a drive capacity of the driver to gradually decrease the difference between the detected peak voltage and the allowable voltage.
    Type: Grant
    Filed: July 5, 2019
    Date of Patent: April 13, 2021
    Assignee: DENSO CORPORATION
    Inventors: Masahiro Yamamoto, Akimasa Niwa
  • Publication number: 20210036697
    Abstract: A gate drive circuit includes a driver for driving a gate of a switching element, a peak voltage detector, and a drive capacity calculator. The peak voltage detector detects a peak voltage at a main terminal of the switching element when the switching element is OFF. The drive capacity calculator calculates a voltage difference value between the detected peak voltage and an allowable voltage value at the main terminal of the switching element, where the allowable voltage is based on the specifications of the switching element. The drive capacity calculator changes a drive capacity of the driver to gradually decrease the difference between the detected peak voltage and the allowable voltage.
    Type: Application
    Filed: October 16, 2020
    Publication date: February 4, 2021
    Inventors: Masahiro YAMAMOTO, Akimasa NIWA
  • Patent number: 10644689
    Abstract: A transistor drive circuit drives a bipolar-type transistor and a MOSFET that are connected in parallel to each other. A temperature detection element that detects a temperature of a the bipolar-type transistor or the MOSFET. When the temperature is equal to or less than a threshold, the transistor drive circuit turns on both of the MOSFET and the bipolar-type transistor. When the temperature exceeds the threshold, the transistor drive circuit turns on only the bipolar-type transistor.
    Type: Grant
    Filed: July 31, 2017
    Date of Patent: May 5, 2020
    Assignee: DENSO CORPORATION
    Inventors: Kohei Shinomiya, Takahiro Iwamura, Akimasa Niwa, Masahiro Yamamoto, Seiji Nishimoto
  • Publication number: 20200021282
    Abstract: A gate drive circuit includes a driver for driving a gate of a switching element, a peak voltage detector, and a drive capacity calculator. The peak voltage detector detects a peak voltage at a main terminal of the switching element when the switching element is OFF. The drive capacity calculator calculates a voltage difference value between the detected peak voltage and an allowable voltage value at the main terminal of the switching element, where the allowable voltage is based on the specifications of the switching element. The drive capacity calculator changes a drive capacity of the driver to gradually decrease the difference between the detected peak voltage and the allowable voltage.
    Type: Application
    Filed: July 5, 2019
    Publication date: January 16, 2020
    Inventors: Masahiro YAMAMOTO, Akimasa NIWA
  • Publication number: 20190363706
    Abstract: A transistor drive circuit drives a bipolar-type transistor and a MOSFET that are connected in parallel to each other. A temperature detection element that detects a temperature of a the bipolar-type transistor or the MOSFET. When the temperature is equal to or less than a threshold, the transistor drive circuit turns on both of the MOSFET and the bipolar-type transistor. When the temperature exceeds the threshold, the transistor drive circuit turns on only the bipolar-type transistor.
    Type: Application
    Filed: July 31, 2017
    Publication date: November 28, 2019
    Applicant: DENSO CORPORATION
    Inventors: Kohei SHINOMIYA, Takahiro IWAMURA, Akimasa NIWA, Masahiro YAMAMOTO, Seiji NISHIMOTO
  • Patent number: 8151098
    Abstract: A signal processing apparatus for processing a periodic signal outputted from a signal source has a central processing unit and a task switch timer. The central processing unit performs multiple tasks including a signal processing task in parallel. In the signal processing task, the central processing unit starts to process the periodic signal after performing a synchronization processing to synchronize with the periodic signal, setting the task switch timer to a predetermined time upon completion of the synchronization processing, and enabling an interrupt to the central processing unit upon completion of the synchronization processing. The task switch timer disables the interrupt to the central processing unit immediately before expiring. The task switch timer outputs a task switch signal to the central processing unit when expiring, so that the central processing unit switches to the signal processing task.
    Type: Grant
    Filed: February 5, 2009
    Date of Patent: April 3, 2012
    Assignee: DENSO CORPORATION
    Inventors: Akimasa Niwa, Masahiro Kamiya, Hideaki Ishihara, Yoshinori Teshima
  • Patent number: 7991986
    Abstract: A microprocessor which is adapted to start a second task at a predetermined time when a first task is running if a current time becomes to be equal to the predetermined time is disclosed. The microprocessor executing an instruction read out from a program address updated every time when each execution of instruction is completed, includes update ceasing means for ceasing the program address from being updated when an stopping time comes in order to abort a first task defined by a first computer program and overwriting means for overwriting the program address with an initial address of a second computer program when a predetermined time comes in order to start to execute a second task defined by the second computer program at the predetermined time.
    Type: Grant
    Filed: September 20, 2007
    Date of Patent: August 2, 2011
    Assignee: DENSO CORPORATION
    Inventors: Tsuyoshi Yamamoto, Takayuki Matsuda, Akimasa Niwa
  • Patent number: 7802135
    Abstract: It is determined that a write access is executed to a stack area of a main memory. It is then determined whether another write access to a corresponding access destination address in the stack area occurred in the past by referring to an access flag table. In contrast, it is determined that a write access is executed to a global area of the main memory. It is then determined whether another write access to a corresponding access destination address in the global area occurred in the past with referring to an access list. Such a configuration can efficiently provide individual advantages of the determination methods using both the access flag table and the address list. The presence or absence of the past saving execution can be efficiently determined at the time of write access.
    Type: Grant
    Filed: April 15, 2008
    Date of Patent: September 21, 2010
    Assignee: DENSO CORPORATION
    Inventor: Akimasa Niwa
  • Patent number: 7725694
    Abstract: A microcomputer includes a CPU capable of performing a plurality of tasks in a parallel time-sharing operation. The tasks include at least one special task having a fixed loop program with a constant increase of an instruction address. When the CPU performs a conditional judgment instruction in the special task, the CPU prohibits reflecting an execution result of the conditional judgment instruction to both of the CPU and a periphery circuit in a case where it is no need to perform an instruction described in the special task after the conditional judgment instruction.
    Type: Grant
    Filed: December 21, 2005
    Date of Patent: May 25, 2010
    Assignee: DENSO CORPORATION
    Inventors: Naoki Ito, Masahiro Kamiya, Hideaki Ishihara, Akimasa Niwa, Takayuki Matsuda, Toshihiko Matsuoka
  • Publication number: 20090204841
    Abstract: A signal processing apparatus for processing a periodic signal outputted from a signal source has a central processing unit and a task switch timer. The central processing unit performs multiple tasks including a signal processing task in parallel. In the signal processing task, the central processing unit starts to process the periodic signal after performing a synchronization processing to synchronize with the periodic signal, setting the task switch timer to a predetermined time upon completion of the synchronization processing, and enabling an interrupt to the central processing unit upon completion of the synchronization processing. The task switch timer disables the interrupt to the central processing unit immediately before expiring. The task switch timer outputs a task switch signal to the central processing unit when expiring, so that the central processing unit switches to the signal processing task.
    Type: Application
    Filed: February 5, 2009
    Publication date: August 13, 2009
    Applicant: DENSO CORPORATION
    Inventors: Akimasa Niwa, Masahiro Kamiya, Hideaki Ishihara, Yoshinori Teshima
  • Publication number: 20080270831
    Abstract: It is determined that a write access is executed to a stack area of a main memory. It is then determined whether another write access to a corresponding access destination address in the stack area occurred in the past by referring to an access flag table. In contrast, it is determined that a write access is executed to a global area of the main memory. It is then determined whether another write access to a corresponding access destination address in the global area occurred in the past with referring to an access list. Such a configuration can efficiently provide individual advantages of the determination methods using both the access flag table and the address list. The presence or absence of the past saving execution can be efficiently determined at the time of write access.
    Type: Application
    Filed: April 15, 2008
    Publication date: October 30, 2008
    Applicant: DENSO CORPORTION
    Inventor: Akimasa Niwa
  • Patent number: 7433494
    Abstract: Provided is a moving body detecting apparatus capable of detecting only a body to be notified without detecting a body similar in feature to the body to be notified. To confirm whether a break-in body appears in static images from a camera, the apparatus sets a monitoring region for monitoring a window portion in the static images and a monitoring region for monitoring a door body portion therein, and produces difference images from the static images. A pixel set existing in common to the difference images continuing in time sequence is extracted from an image composed so that pixel values reach a maximum. On the basis of the motion vector, a decision is made as to whether the movement of the pixel set from the window portion to the door body portion occurs or not.
    Type: Grant
    Filed: September 16, 2003
    Date of Patent: October 7, 2008
    Assignee: DENSO CORPORATION
    Inventor: Akimasa Niwa
  • Publication number: 20080072013
    Abstract: A microprocessor which is adapted to start a second task at a predetermined time when a first task is running if a current time becomes to be equal to the predetermined time is disclosed. The microprocessor executing an instruction read out from a program address updated every time when each execution of instruction is completed, includes update ceasing means for ceasing the program address from being updated when an stopping time comes in order to abort a first task defined by a first computer program and overwriting means for overwriting the program address with an initial address of a second computer program when a predetermined time comes in order to start to execute a second task defined by the second computer program at the predetermined time.
    Type: Application
    Filed: September 20, 2007
    Publication date: March 20, 2008
    Applicant: DENSO CORPORATION
    Inventors: Tsuyoshi Yamamoto, Takayuki Matsuda, Akimasa Niwa