Patents by Inventor Kyohko Hirai

Kyohko Hirai 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).

  • Spread spectrum clock generator
    Patent number: 8421508
    Abstract: A spread spectrum clock generator includes a phase comparator to detect a phase difference between a reference input clock signal and a feedback signal and output a control voltage, a voltage controlled oscillator to generate an output clock signal with a frequency in line with the control voltage, a phase selector to select any of equally divided phases of one cycle of the output clock signal, generate and transmit a phase shift clock signal to the phase comparator as the feedback signal, and a phase controller to decide a phase of the rising edge of the phase shift clock signal and control the phase selector to select the decided phase, and generate a second phase shift amount, decide the rising edge of the phase shift clock signal to and subject the output clock signal to spread spectrum modulation by the second phase shift amount.
    Type: Grant
    Filed: March 16, 2012
    Date of Patent: April 16, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Kyohko Hirai, Tohru Kanno
  • SPREAD SPECTRUM CLOCK GENERATOR
    Publication number: 20120235717
    Abstract: A spread spectrum clock generator includes a phase comparator to detect a phase difference between a reference input clock signal and a feedback signal and output a control voltage, a voltage controlled oscillator to generate an output clock signal with a frequency in line with the control voltage, a phase selector to select any of equally divided phases of one cycle of the output clock signal, generate and transmit a phase shift clock signal to the phase comparator as the feedback signal, and a phase controller to decide a phase of the rising edge of the phase shift clock signal and control the phase selector to select the decided phase, and generate a second phase shift amount, decide the rising edge of the phase shift clock signal to and subject the output clock signal to spread spectrum modulation by the second phase shift amount.
    Type: Application
    Filed: March 16, 2012
    Publication date: September 20, 2012
    Applicant: Ricoh Company, Ltd.
    Inventors: Kyohko Hirai, Tohru Kanno