Patents by Inventor Toshikatsu Kiriyama

Toshikatsu Kiriyama 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 matrix equipment having a series circuit of relay coil and self-holding diode at each crosspoint
    Patent number: 4231017
    Abstract: A switching matrix equipment is disclosed for use in a telecommunication switching system. Each crosspoint comprises a series circuit of a relay coil and a self-holding diode. First and second switch groups cooperate to select a crosspoint and to fire a self-holding diode of the cross point. After the self-holding diode is fired, the crosspoint related is held or sustained by means of a third switch group with a lower voltage than the threshold voltage of the self-holding diode.
    Type: Grant
    Filed: February 22, 1979
    Date of Patent: October 28, 1980
    Assignee: Hitachi, Ltd.
    Inventors: Toshikatsu Kiriyama, Yoshiro Hasegawa