Patents by Inventor Seizo Ohta

Seizo Ohta 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).

  • Key telephone set with speaker phone
    Patent number: D298938
    Type: Grant
    Filed: March 12, 1987
    Date of Patent: December 13, 1988
    Assignee: NEC Corporation
    Inventors: Kenichi Morikawa, Masafuku Akatsu, Tatsuya Kato, Seizo Ohta, Takeshi Nakatani
  • Key telephone set with speakerphone and visual display panel
    Patent number: D298939
    Type: Grant
    Filed: March 12, 1987
    Date of Patent: December 13, 1988
    Assignee: NEC Corporation
    Inventors: Kenichi Morikawa, Masafuku Akatsu, Tatsuya Kato, Seizo Ohta, Takeshi Nakatani
  • Key telephone set
    Patent number: D300926
    Type: Grant
    Filed: March 12, 1987
    Date of Patent: May 2, 1989
    Assignee: NEC Corporation
    Inventors: Kenichi Morikawa, Masafuku Akatsu, Tatsuya Kato, Seizo Ohta, Takeshi Nakatani
  • Telephone set
    Patent number: D342252
    Type: Grant
    Filed: July 14, 1992
    Date of Patent: December 14, 1993
    Assignee: NEC Corporation
    Inventors: Masafuku Akatsu, Akira Abe, Hitoshi Tsuchida, Seizo Ohta, Takeshi Nakatani
  • Telephone set
    Patent number: D345557
    Type: Grant
    Filed: July 14, 1992
    Date of Patent: March 29, 1994
    Assignee: NEC Corporation
    Inventors: Masafuku Akatsu, Akira Abe, Hitoshi Tsuchida, Seizo Ohta, Takeshi Nakatani