Patents by Inventor Masaru Kudoh

Masaru Kudoh 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).

  • Electronic key telephone set circuit for permitting dialing during failure of commercial power supplied to the set
    Patent number: 4392024
    Abstract: An electronic key telephone set in an electronic key telephone system which is connected to the office line during the power failure by a power failure detecting relay in the key service unit having a common selection signal sender is provided with a circuit for detecting power failure to the key telephone system, additional contacts to respective keys of the key dial and a selection signal generator coupled with the additional contacts. The selection signal generator is connected to the voice signal pair line by a transistor which is turned on by a signal from the power failure detecting circuit during the power failure, and receives a D.C. power on the office line to be operable, so that a call may be generated from the key telephone set even during the power failure to the key telephone system. The signal from the power failure detecting circuit is fed to the transistor through a photo-coupler element.
    Type: Grant
    Filed: December 8, 1981
    Date of Patent: July 5, 1983
    Assignees: Nitsuko Limited, Nippon Telegraph & Telephone Public Corporation
    Inventors: Tsuyoshi Shinoi, Keisuke Mochizuki, Yoshimi Suzuki, Masaru Kudoh, Wataru Hashimoto