Patents by Inventor Ichiro Tomizawa

Ichiro Tomizawa 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).

  • Subscriber line radio concentration system with automatic response for a loop back test
    Patent number: 4622438
    Abstract: In a subscriber line radio concentration system for concentrating a plurality of subscriber terminal stations through radio channels to a master station, at least one of the subscriber terminal stations comprises an automatic response equipment. The automatic response equipment can automatically respond to a continuous ringing signal from the master station, thereby enabling a loop back test to be carried out automatically without the necessity of the attendance at the subscriber station of maintenance or other personnel.
    Type: Grant
    Filed: November 26, 1984
    Date of Patent: November 11, 1986
    Assignee: Fujitsu Limited
    Inventors: Takafumi Shimizu, Ichiro Tomizawa