Patents by Inventor Satoyuki Matsui

Satoyuki Matsui 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).

  • Optical loop back and line test apparatus
    Patent number: 5319482
    Abstract: A testing apparatus is presented which evaluates the performance of optical signal transmissions in the 1.3 .mu.m wavelength region, independently or simultaneously with signal transmission. An optical signal is transmitted in the network.fwdarw.user direction in a thermo-optic (TO) switch 11, and the signal is also looped in the direction A of an optical directional coupler 3. An optical time domain reflectometer (OTDR) 10 Generates a test beam at 1.55 .mu.m wavelength region, which is reflected by a wavelength selective filter 8 back to the OTDR 10 in the user-network direction. The apparatus is thus able to perform testing of the transmission cable 7 simultaneously with the signal transmission. When an operating problem is to be pinpointed in the system, the optical switch 11 is switched so as to permit the signal from a line terminal LT 1 to transmit in the network.fwdarw.user direction.
    Type: Grant
    Filed: February 10, 1992
    Date of Patent: June 7, 1994
    Assignee: Nippon Telegraph and Telephone Corporation
    Inventors: Toshiyuki Tsuchiya, Jun Sato, Kazuyoshi Ohno, Satoyuki Matsui