Patents by Inventor Yoshifumi Yoritomi

Yoshifumi Yoritomi 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).

  • Patent number: 5981973
    Abstract: A thin film transistor structure for use in driving liquid crystal display elements has a semiconductor active layer, a control electrode layer underlying the active layer with an insulating layer interposed therebetween and first and second main electrode layers formed on or above the active layer in a spaced relation with each other to define a channel in the active layer in cooperation with the control electrode layer between the main electrode layers. The active layer has a first peripheral edge portion generally perpendicular to the direction of the channel and a second peripheral edge portion generally not perpendicular to the direction of the channel. The first and/or second main electrode layer extends over the first and/or second peripheral edge portion of the active layer such that at least a part of the first peripheral edge portion and/or at least part of the second peripheral edge portion of the active layer has its side face directly covered with the main electrode layer.
    Type: Grant
    Filed: November 17, 1997
    Date of Patent: November 9, 1999
    Assignee: Hitachi, Ltd.
    Inventors: Eiji Matsuzaki, Akihiro Kenmotsu, Yoshifumi Yoritomi, Toshiyuki Koshita, Takao Takano, Mitsuo Nakatani
  • Patent number: 5821565
    Abstract: A thin film transistor structure for use in driving liquid crystal display elements has a semiconductor active layer, a control electrode layer underlying the active layer with an insulating layer interposed therebetween and first and second main electrode layers formed on or above the active layer in a spaced relation with each other to define a channel in the active layer in cooperation with the control electrode layer between the main electrode layers. The active layer has a first peripheral edge portion generally perpendicular to the direction of the channel and a second peripheral edge portion generally not perpendicular to the direction of the channel. The first and/or second main electrode layer extends over the first and/or second peripheral edge portion of the active layer such that at least a part of the first peripheral edge portion and/or at least part of the second peripheral edge portion of the active layer has its side face directly covered with the main electrode layer.
    Type: Grant
    Filed: December 15, 1995
    Date of Patent: October 13, 1998
    Assignee: Hitachi, Ltd.
    Inventors: Eiji Matsuzaki, Akihiro Kenmotsu, Yoshifumi Yoritomi, Toshiyuki Koshita, Takao Takano, Mitsuo Nakatani
  • Patent number: 5493129
    Abstract: A thin film transistor structure for use in driving liquid crystal display elements has a semiconductor active layer, a control electrode layer underlying the active layer with an insulating layer interposed therebetween and first and second main electrode layers formed on or above the active layer in a spaced relation with each other to define a channel in the active layer in cooperation with the control electrode layer between the main electrode layers. The active layer has a first peripheral edge portion generally perpendicular to the direction of the channel and a second peripheral edge portion generally not perpendicular to the direction of the channel. The first and/or second main electrode layer extends over the first and/or second peripheral edge portion of the active layer such that at least a part of the first peripheral edge portion and/or at least part of the second peripheral edge portion of the active layer has its side face directly covered with the main electrode layer.
    Type: Grant
    Filed: June 27, 1989
    Date of Patent: February 20, 1996
    Assignee: Hitachi, Ltd.
    Inventors: Eiji Matsuzaki, Akihiro Kenmotsu, Yoshifumi Yoritomi, Toshiyuki Koshita, Takao Takano, Mitsuo Nakatani
  • Patent number: 5157470
    Abstract: Disclosed are a thin film transistor comprising a first electrode pattern formed on an insulating substrate as a gate electrode, a first insulating film formed as a gate insulating film and covering at least the electrode pattern, a semiconductor thin film pattern mainly composed of silicon formed on the insulating film, the semiconductor thin film pattern overlapping the first electrode pattern and the existing region thereof being limited, second and third electrodes formed on the semiconductor thin film pattern as a drain electrode and a source electrode, the second and third electrodes covering a portion of the semiconductor thin film pattern and being spaced apart each other, and a thin film containing silicon oxide formed over the semiconductor film, the second and third electrodes being formed upon the silicon oxide film, a method of manufacturing the thin film transistor, an active matrix circuit board using the thin film transistors, and an image display device using the active matrix circuit board.
    Type: Grant
    Filed: May 21, 1991
    Date of Patent: October 20, 1992
    Assignee: Hitachi, Ltd.
    Inventors: Eiji Matsuzaki, Takao Takano, Toshiyuki Koshita, Yoshifumi Yoritomi, Akihiro Kenmotsu
  • Patent number: 4902394
    Abstract: A sputtering method and apparatus for use in forming thin films on a substrate. The power output of a sputtering power source is periodically changed to a high level power and a low level power, and each film is deposited to a thickness corresponding to the integrated value of the high level power, whereby a desired thickness can be obtained in any of multilayer films having mutually different film thickness ratios.
    Type: Grant
    Filed: January 20, 1988
    Date of Patent: February 20, 1990
    Assignee: Hitachi, Ltd.
    Inventors: Akihiro Kenmotsu, Shigeru Kobayashi, Kunihiko Watanabe, Eiji Matsuzaki, Yoshifumi Yoritomi, Toshiyuki Koshita, Mitsuo Nakatani