Patents by Inventor Akihiko Hiramatu

Akihiko Hiramatu 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).

  • 1.times.N communication system for private branch exchange
    Patent number: 5884162
    Abstract: A press-talk trunk is a communication system receives press-talk signals from voice terminals having press-talk switches. In one aspect of the invention, the press-talk trunk is scanned by a central controller that selects an active press-talk signal and sets up a corresponding 1.times.N voice communication path among the terminals. In another aspect of the invention, the press-talk truck itself selects an active press-talk signal and notifies the central controller by means of an interrupt. In yet another aspect of the invention, the press-talk trunk also receives voice signals from all the terminals, selects a voice signal from a terminal having an active press-talk signal, and sends that voice signal back to all the other terminals. In still another aspect of the invention, two or more press-talk trunks are cascaded.
    Type: Grant
    Filed: July 9, 1992
    Date of Patent: March 16, 1999
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Shigeru Yamazaki, Akihiko Hiramatu, Kazuo Seko