Patents by Inventor Tadahiro Yamaguchi

Tadahiro Yamaguchi 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).

  • AM stereo signal demodulation circuit
    Patent number: 4215316
    Abstract: A stereo signal demodulation for obtaining left and right channel signals from an input stereo signal. A differential amplifier is coupled to a constant current source and first and second multipliers are coupled to the differential amplifier. A dividing circuit is coupled to the amplifier and the resulting channel signals are obtained in full wave rectified form.
    Type: Grant
    Filed: October 5, 1978
    Date of Patent: July 29, 1980
    Assignee: Pioneer Electronic Corporation
    Inventors: Tadahiro Yamaguchi, Koki Aizawa
  • Audio signal compression and expansion system
    Patent number: 4145664
    Abstract: The auxilliary signal path in a compander system includes, in series, a first amplifier 7, a weighting function amplifier 8, and a detection circuit 9. The output of the latter controls the gain of a voltage-controlled variable gain circuit 11 also connected to the first amplifier output, and the integrated output of the variable gain circuit is fed back to the input of the first amplifier via a subtraction circuit 13 also supplied with the auxilliary signal path input. Alternatively, the first amplifier may comprise an operational amplifier, in which case the integrated signal is directly coupled to one of its inputs.
    Type: Grant
    Filed: March 31, 1978
    Date of Patent: March 20, 1979
    Assignee: Pioneer Electronic Corporation
    Inventors: Saburo Takaoka, Fumihiko Yokogawa, Tadahiro Yamaguchi