Patents by Inventor Sou Fujioka

Sou Fujioka 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).

  • Switching amplifier
    Patent number: 7224217
    Abstract: A switching amplifier including a PWM circuit 14, a driver 15, a switching output circuit 16 and an LPF 17 is provided with a fluctuation detection circuit 12 for detecting fluctuations in the power supply voltage. The fluctuation detection circuit 12 includes detection resistors 122 and 123 connected in series between a positive power supply 19 and a negative power supply 20. A fluctuating signal RPL occurring at a fluctuation detection terminal 121 is supplied to the inverted input terminal of a differential amplifier 131 of a non-inverted amplifier circuit 13. The non-inverted amplifier circuit 13 inverts the fluctuating signal RPL, mixes the inverted fluctuating signal into the input signal eS, amplifies the mixed signal, and supplying the amplified signal to the PWM circuit 14.
    Type: Grant
    Filed: February 28, 2005
    Date of Patent: May 29, 2007
    Assignee: Onkyo Corporation
    Inventors: Kazuhiro Hida, Joji Kasai, Yoshitaka Handa, Sou Fujioka, Mamoru Sekiya
  • Switching amplifier
    Publication number: 20050212592
    Abstract: A switching amplifier including a PWM circuit 14, a driver 15, a switching output circuit 16 and an LPF 17 is provided with a fluctuation detection circuit 12 for detecting fluctuations in the power supply voltage. The fluctuation detection circuit 12 includes detection resistors 122 and 123 connected in series between a positive power supply 19 and a negative power supply 20. A fluctuating signal RPL occurring at a fluctuation detection terminal 121 is supplied to the inverted input terminal of a differential amplifier 131 of a non-inverted amplifier circuit 13. The non-inverted amplifier circuit 13 inverts the fluctuating signal RPL, mixes the inverted fluctuating signal into the input signal eS, amplifies the mixed signal, and supplying the amplified signal to the PWM circuit 14.
    Type: Application
    Filed: February 28, 2005
    Publication date: September 29, 2005
    Inventors: Kazuhiro Hida, Joji Kasai, Yoshitaka Handa, Sou Fujioka, Mamoru Sekiya