Patents by Inventor Atsumi Fujiwara

Atsumi Fujiwara 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).

  • Medium-frequency radio transmission system
    Patent number: 5689804
    Abstract: A medium-frequency radio transmission system is formed by installing a receiving antenna for receiving an amplitude-modulated medium-frequency radio wave at the rooftop of an existing building, receiving the medium-frequency radio wave, coupling the received medium-frequency radio wave to an existing distributing cable or distributing conductive piping with or without a coupler for said radio wave, and transmitting the radio wave to a predetermined floor. At the predetermined floor the basement or tunnel of an existing building such as underground shopping mall, underground parking lot, underground railway, road tunnel or deep space of massive building is provided with a coupling such as an existing loop-like or linear wiring or piping line with or without coupler.
    Type: Grant
    Filed: January 16, 1996
    Date of Patent: November 18, 1997
    Assignees: NHK Integrated Technology Inc., Nippon Hoso Kyokai
    Inventors: Tadao Sugita, Tatehiko Toyosawa, Kazumi Shoji, Shinichi Watanabe, Atsumi Fujiwara, Masaaki Kitanda
  • Medium-frequency radio broadcasting retransmission system for confined and electromagnetically shielded areas
    Patent number: 5537637
    Abstract: A medium-frequency radio transmission system is formed by installing a receiving antenna for receiving an amplitude-modulated medium-frequency radio wave at the rooftop of an existing building, receiving the medium-frequency radio wave, coupling the received medium-frequency radio wave to an existing distributing cable or distributing conductive piping with or without a coupler for the radio wave, and transmitting the radio wave to a predetermined floor. At the predetermined floor the basement or tunnel of an existing building such as underground shopping mall, underground parking lot, underground railway, road tunnel or deep space of massive building is provided with a coupling such as an existing loop-like or linear wiring or piping line with or without a coupler.
    Type: Grant
    Filed: March 8, 1994
    Date of Patent: July 16, 1996
    Assignees: NHK Integrated Technology, Inc., Nippon Hoso Kyokai
    Inventors: Tadao Sugita, Tatehiko Toyosawa, Kazumi Shoji, Shinichi Watanabe, Atsumi Fujiwara, Masaaki Kitanda
  • Matching circuit
    Patent number: 4945317
    Abstract: A matching circuit is connected between a source circuit and a load circuit. The matching circuit is made up of an impedance transforming circuit and a balance-to-unbalance signal-transforming circuit. If necessary, means for blocking the DC components intervene between those transforming circuits. The impedance transforming circuit is made up of inductive and capacitive elements. The matching circuit is reversible.
    Type: Grant
    Filed: September 20, 1988
    Date of Patent: July 31, 1990
    Assignees: Nippon Hoso Kyokai, Kabushiki Kaisha Toshiba
    Inventors: Tutomu Sato, Haruhiko Yura, Yoshihiko Nasu, Atsumi Fujiwara, Shigeo Mori