Patents by Inventor Ryoichi Hatsumi

Ryoichi Hatsumi 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).

  • Signal identification system
    Patent number: 4001521
    Abstract: A signal identification system, in which a signal of a specified frequency included in an analog signal indicated by an input pulse train converted from the analog signal is detected from the pulse train. The input pulse train is multiplied by two reference wave pulse trains having peak valves following the signal of the specified frequency but displaced by .pi./2 in phase from each other, respectively. The results of the multiplications are separately accumulated. The signal of the specified frequency is identified by utilizing a fact that the absolute value of at least one of the accumulated values exceeds a predetermined threshold value in the range of a permissible frequency deviation of the signal of the specified frequency and in the range of its permissible level fluctuation.
    Type: Grant
    Filed: May 14, 1975
    Date of Patent: January 4, 1977
    Assignee: Kokusai Denshin Denwa Kabushiki Kaisha
    Inventors: Yasuo Fukata, Ryoichi Hatsumi