Patents by Inventor Masaaki Terai

Masaaki Terai 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).

  • Automatic signal level adjusting circuits for use in telephone sets
    Patent number: 4143247
    Abstract: There are provided a current detecting resistance element connected in series with a loop for supplying current to a telephone set, a switching circuit including a three terminal semiconductor switching element connected to be ON.OFF controlled by the voltage drop across the resistance element, and an impedance element controlled by the ON.OFF operation of the switching element to be connected across the loop for adding AC loss.
    Type: Grant
    Filed: October 25, 1977
    Date of Patent: March 6, 1979
    Assignee: Nippon Telegraph and Telephone Public Corporation
    Inventors: Makoto Yoshitoshi, Isao Kawashima, Hideo Kishimoto, Masaaki Terai, Kazumi Kato
  • Transmitting and receiving apparatus
    Patent number: 4002860
    Abstract: Only one reversible electro-acoustic converter is used to act without a press-to-talk switch or the like as a transmitter and a receiver. The electro-acoustic converter is connected to a communication line through two 2 - 4 converters in the form of hybrid transformers which are interconnected to form a transmitting system and a receiving system.
    Type: Grant
    Filed: April 2, 1975
    Date of Patent: January 11, 1977
    Assignee: Nippon Telegraph and Telephone Public Corporation
    Inventors: Masaaki Terai, Kazuhiko Kakehi, Ryoichi Matsuda, Giichi Ito