Patents by Inventor Sueo Sakata

Sueo Sakata 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).

  • Interconnection for electric power system
    Patent number: 5111377
    Abstract: In a power interconnection system between an electric power system and a power converter which makes AC power from a DC power source, a positive feed-back loop is constituted so as to include a frequency deviation detector, a band-pass filter, an inert zone circuit, an amplifier, an adder, a phase controller, an inverter controller, an inverter and an interconnection reactor. Thereby a sufficiently great frequency fluctuation is made after opening of a branch line switch, so as to produce a frequency abnormality signal to be given to a disconnection switch; and disconnection is made certainly.
    Type: Grant
    Filed: March 1, 1991
    Date of Patent: May 5, 1992
    Assignees: Shikoku Research Institute Incorporated, Mitsubishi Denki Kabushiki Kaisha
    Inventors: Hiromasa Higasa, Fumihiko Ishikawa, Shigenori Matsumura, Sueo Sakata, Masayoshi Kumano
  • Method of producing semiconductor wafer through gettering using spherical abrasives
    Patent number: 5051375
    Abstract: Disclosed is a method of producing a semiconductor wafer through gettering by means of sand blasting in a semiconductor wafer fabrication process. The method includes blasting abrasives each having a configuration at least similar to a sphere against a back surface of the semiconductor wafer, causing shear stress having a maximum point in the interior of the wafer to be generated, whereby damage is produced mainly in the interior of the wafer.
    Type: Grant
    Filed: July 10, 1989
    Date of Patent: September 24, 1991
    Assignees: Kyushu Electronic Metal Co., Ltd., Osaka Titanium Co., Ltd.
    Inventors: Sueo Sakata, Yasunori Oka, Toshio Naritomi