Patents by Inventor Kenichi Miyagaki

Kenichi Miyagaki 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).

  • Pop sound reduction circuit and voice output amplification device
    Patent number: 7142048
    Abstract: A pop sound reduction circuit comprises a pulse width modulation amplifier configured to amplify a reference voltage to an intermediate amplitude of a pulse width modulated signal, a first switch configured to activate and deactivate the pulse width modulation amplifier, a buffer amplifier configured to generate a DC voltage equal to the reference voltage, a second switch configured to activate and deactivate the buffer amplifier, and a control circuit configured to close and open the first and second switches complementary, depending on a potential in a leading region of the reference voltage which rises from a time of turning-on of a power source as well as a potential in a trailing region of the reference voltage which falls from a time of turning-off of the power source.
    Type: Grant
    Filed: September 25, 2002
    Date of Patent: November 28, 2006
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kenichi Miyagaki, Kouichi Yamashita
  • Pop sound reduction circuit and voice output amplification device
    Publication number: 20030058040
    Abstract: A pop sound reduction circuit comprises a pulse width modulation amplifier configured to amplify a reference voltage to an intermediate amplitude of a pulse width modulated signal, a first switch configured to activate and deactivate the pulse width modulation amplifier, a buffer amplifier configured to generate a DC voltage equal to the reference voltage, a second switch configured to activate and deactivate the buffer amplifier, and a control circuit configured to close and open the first and second switches complementary, depending on a potential in a leading region of the reference voltage which rises from a time of turning-on of a power source as well as a potential in a trailing region of the reference voltage which falls from a time of turning-off of the power source.
    Type: Application
    Filed: September 25, 2002
    Publication date: March 27, 2003
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Kenichi Miyagaki, Kouichi Yamashita