Patents by Inventor Noritomo Arai

Noritomo Arai 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).

  • Patent number: 4125749
    Abstract: The key button telephone system comprises a key service unit and a plurality of key telephone units. The key service unit and each key telephone unit are interconnected by a pair of cables, one of which is used as a talking circuit and the other is used to transmit and receive information signals and operating power. The key service unit comprises a line circuit for supervising the state of a line, a station unit for supervising the line circuit, and for supplying to the key telephone unit an information signal representing the state of the line and the operating power, a switching network controlled by the control output from the station unit for connecting the key telephone unit to the line, and a common control circuit for controlling the line circuit and the station unit.
    Type: Grant
    Filed: August 5, 1976
    Date of Patent: November 14, 1978
    Assignee: Tamura Electric Works, Ltd.
    Inventors: Toshiharu Kinoshita, Yoshio Shinoda, Takashi Oyamada, Mitsuo Masuda, Noritomo Arai