Patents by Inventor Takashi Wakamatsu

Takashi Wakamatsu 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).

  • Least cost routing with repeated searches for lower cost route
    Patent number: 6023501
    Abstract: In a communications network, a database is searched for a least cost route in response to a call request from a subscriber, and a connection is established along the least cost route between the calling subscriber and a called subscriber. For the duration of the call, the database is repeatedly searched for a route having a cost lower than the cost of a previously determined route. If the route of lower cost is detected, a new connection is established along the lower cost route, instead of the currently established connection.
    Type: Grant
    Filed: March 3, 1999
    Date of Patent: February 8, 2000
    Assignee: NEC Corporation
    Inventor: Takashi Wakamatsu
  • Method and device for improved photoelectric conversion
    Patent number: 5685919
    Abstract: Efficiency of a photoelectric conversion device is increased by inducing a surface plasmon also on a metallic electrode located on the side of the device where light is incident. Incident He-Ne laser light is refracted by a semicylindrical lens and is incident on a magnesium fluoride layer and an Al electrode. The surface plasmon is absorbed by a copper phthalocyanine layer to give a photoelectric current between the Al electrode and an Ag electrode.
    Type: Grant
    Filed: March 13, 1996
    Date of Patent: November 11, 1997
    Assignee: Agency of Industrial Science & Technology
    Inventors: Kazuhiro Saito, Hiroshi Yokoyama, Takashi Wakamatsu