Patents by Inventor Kazumasa Kubotera

Kazumasa Kubotera 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: 9160327
    Abstract: A semiconductor device including an input terminal to receive an input signal and an output terminal to output an output signal includes delay elements connected in series with the input terminal and each to assign the delay to the input signal input from the input terminal, selectors connected to output sides of the delay elements and each to select one of output signals of the delay elements based on a selection signal for selecting the one of the output signals of the delay elements to return the selected one of the output signals to the output terminal, and delay circuits disposed corresponding to the selectors and each to cause switching of the selection signal input into a corresponding one of the selectors to occur after switching of a signal level of the input signal input into the corresponding one of the selectors serving as a signal turning point.
    Type: Grant
    Filed: May 23, 2013
    Date of Patent: October 13, 2015
    Assignee: FUJITSU LIMITED
    Inventors: Masaki Fujioka, Koji Migita, Kazumasa Kubotera, Yasutaka Kanayama
  • Patent number: 8847643
    Abstract: A semiconductor device includes a delay part configured to assign a delay to an input signal, a phase detector configured to detect a phase of an output signal output from the delay part, a setting part configured to set a stable operations range of the phase of the output signal based on phase information output from the phase detector, and an error detector configured to set an acceptable range corresponding to the stable operations range, determine whether a phase of the output signal falls within the acceptable range, and change the acceptable range based on an extraneous factor of an input signal of the delay part.
    Type: Grant
    Filed: July 23, 2013
    Date of Patent: September 30, 2014
    Assignee: Fujitsu Limited
    Inventors: Koji Migita, Yoshito Koyama, Kazumasa Kubotera, Yasutaka Kanayama
  • Patent number: 8745475
    Abstract: A semiconductor apparatus includes a delay circuit to apply delay to an input signal, a phase detector to detect a phase of an output signal which is outputted from the delay circuit, a filter to set a range of the phase of the output signal for stable operation based on phase information outputted from the phase detector, a counter to count a number of detections of the output signal when the phase deviates from the range for stable operation, a discount controller to generate a discount signal indicating a discount number for the number counted by the counter, in accordance with an operating condition or an external factor outside the delay circuit and an error detector to determine whether or not an error of the phase of the output signal has occurred based on the number counted by the counter and a discount number indicated by the discount signal.
    Type: Grant
    Filed: March 16, 2012
    Date of Patent: June 3, 2014
    Assignee: Fujitsu Limited
    Inventors: Koji Migita, Kazumasa Kubotera
  • Patent number: 8698536
    Abstract: Plural unit delay circuits connected in series and an output circuit that non-inverts or inverts and outputs an output signal in accordance with a set signal are included. A first unit delay circuit includes a selector that outputs a signal input to a second input terminal when the set signal is “0”, and outputs a signal input to a first input terminal when the set signal is “1”, and an inverter that inverts and outputs an output of the selector from a second output terminal. A second unit delay circuit includes an inverter that inverts the signal input to the first input terminal and outputs from a first output terminal, and a selector that outputs the signal input to the second input terminal when the set signal is “0”, and outputs an output of the inverter when the set signal is “1” from the second output terminal.
    Type: Grant
    Filed: February 27, 2013
    Date of Patent: April 15, 2014
    Assignees: Fujitsu Limited, Fujitsu Semiconductor Limited
    Inventors: Kazumasa Kubotera, Yasutaka Kanayama, Masaki Fujioka, Hiroshi Miyake
  • Publication number: 20130307597
    Abstract: A semiconductor device includes a delay part configured to assign a delay to an input signal, a phase detector configured to detect a phase of an output signal output from the delay part, a setting part configured to set a stable operations range of the phase of the output signal based on phase information output from the phase detector, and an error detector configured to set an acceptable range corresponding to the stable operations range, determine whether a phase of the output signal falls within the acceptable range, and change the acceptable range based on an extraneous factor of an input signal of the delay part.
    Type: Application
    Filed: July 23, 2013
    Publication date: November 21, 2013
    Applicant: FUJITSU LIMITED
    Inventors: Koji MIGITA, Yoshito KOYAMA, Kazumasa Kubotera, Yasutaka Kanayama
  • Publication number: 20130257501
    Abstract: Plural unit delay circuits connected in series and an output circuit that non-inverts or inverts and outputs an output signal in accordance with a set signal are included. A first unit delay circuit includes a selector that outputs a signal input to a second input terminal when the set signal is “0”, and outputs a signal input to a first input terminal when the set signal is “1”, and an inverter that inverts and outputs an output of the selector from a second output terminal. A second unit delay circuit includes an inverter that inverts the signal input to the first input terminal and outputs from a first output terminal, and a selector that outputs the signal input to the second input terminal when the set signal is “0”, and outputs an output of the inverter when the set signal is “1” from the second output terminal.
    Type: Application
    Filed: February 27, 2013
    Publication date: October 3, 2013
    Applicants: FUJITSU SEMICONDUCTOR LIMITED, FUJITSU LIMITED
    Inventors: Kazumasa KUBOTERA, Yasutaka KANAYAMA, Masaki FUJIOKA, Hiroshi MIYAKE
  • Patent number: 8547133
    Abstract: In a semiconductor device, a selector selects a different reference voltage depending on whether the impedance of a transmitter or of a receiver is to be adjusted, and causes a reference voltage generator to generate the selected reference voltage. The reference voltage generator generates the reference voltage selected by the selector and applies the generated reference voltage to an impedance adjuster. The impedance adjuster adjusts the impedance of the transmitter and the impedance of the receiver, separately from each other, in accordance with the input reference voltage.
    Type: Grant
    Filed: September 22, 2011
    Date of Patent: October 1, 2013
    Assignee: Fujitsu Limited
    Inventors: Noriyuki Tokuhiro, Kazumasa Kubotera, Yasutaka Kanayama
  • Publication number: 20130254434
    Abstract: A semiconductor device including an input terminal to receive an input signal and an output terminal to output an output signal includes delay elements connected in series with the input terminal and each to assign the delay to the input signal input from the input terminal, selectors connected to output sides of the delay elements and each to select one of output signals of the delay elements based on a selection signal for selecting the one of the output signals of the delay elements to return the selected one of the output signals to the output terminal, and delay circuits disposed corresponding to the selectors and each to cause switching of the selection signal input into a corresponding one of the selectors to occur after switching of a signal level of the input signal input into the corresponding one of the selectors serving as a signal turning point.
    Type: Application
    Filed: May 23, 2013
    Publication date: September 26, 2013
    Applicant: FUJITSU LIMITED
    Inventors: Masaki Fujioka, Koji Migita, Kazumasa Kubotera, Yasutaka Kanayama
  • Publication number: 20120290903
    Abstract: A semiconductor apparatus includes a delay circuit to apply delay to an input signal, a phase detector to detect a phase of an output signal which is outputted from the delay circuit, a filter to set a range of the phase of the output signal for stable operation based on phase information outputted from the phase detector, a counter to count a number of detections of the output signal when the phase deviates from the range for stable operation, a discount controller to generate a discount signal indicating a discount number for the number counted by the counter, in accordance with an operating condition or an external factor outside the delay circuit and an error detector to determine whether or not an error of the phase of the output signal has occurred based on the number counted by the counter and a discount number indicated by the discount signal.
    Type: Application
    Filed: March 16, 2012
    Publication date: November 15, 2012
    Applicant: FUJITSU LIMITED
    Inventors: Koji MIGITA, Kazumasa KUBOTERA
  • Publication number: 20120153988
    Abstract: In a semiconductor device, a selector selects a different reference voltage depending on whether the impedance of a transmitter or of a receiver is to be adjusted, and causes a reference voltage generator to generate the selected reference voltage. The reference voltage generator generates the reference voltage selected by the selector and applies the generated reference voltage to an impedance adjuster. The impedance adjuster adjusts the impedance of the transmitter and the impedance of the receiver, separately from each other, in accordance with the input reference voltage.
    Type: Application
    Filed: September 22, 2011
    Publication date: June 21, 2012
    Applicant: FUJITSU LIMITED
    Inventors: Noriyuki Tokuhiro, Kazumasa Kubotera, Yasutaka Kanayama
  • Patent number: 7292787
    Abstract: The present invention relates to the selected-wavelength tuning apparatus which is provided with an AOTF, a radio-frequency signal generator, an optical detector, and a controller for detecting lights emitted from the AOTF with the optical detector and for controlling a frequency of the radio-frequency generator so as to detect a light of predetermined wavelength.
    Type: Grant
    Filed: February 1, 2000
    Date of Patent: November 6, 2007
    Assignee: Fujitsu Limited
    Inventors: Yutaka Kai, Hiroshi Onaka, Yoshihiro Saito, Kazumasa Kubotera