Patents by Inventor Toshihumi Yoshikawa

Toshihumi Yoshikawa 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: 5648687
    Abstract: A resin for sealing a compound semiconductor is here disclosed which contains, as a matrix, a siloxane compound for producing a silicone resin by addition reaction and which has a group comprising the bond of an organic group and an oxy group. The group comprising the bond of the organic group and the oxy group bonds to a terminal of the molecule of the siloxane compound, and as this group comprising the bond, 0.1 to 10% by weight, preferably 0.1 to 1.5% by weight of an alkoxy group (--OR') is used. A compound semiconductor chip is covered with the resin for sealing the compound semiconductor and then reacted under predetermined conditions to produce a silicone resin and simultaneously to chemically bond a siloxane group (--Si--O--) in the silicone resin to an element in a portion of the compound semiconductor chip which comes in contact with the silicone resin.
    Type: Grant
    Filed: March 8, 1994
    Date of Patent: July 15, 1997
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yoshihiko Matsuo, Kazuo Kusuda, Naoki Sata, Toshihumi Yoshikawa, Tsuneo Matsumura
  • Patent number: 4318115
    Abstract: A photoelectric semiconductor device is disclosed which exhibits a reduced spectral sensitivity in a desired wavelength zone. An N(P) type impurity region is formed in a P(N) type semiconductor substrate to establish a first PN junction functioning as a first photodiode. A P(N) type impurity region is shallowly formed in the N(P) type impurity region to establish a second PN junction functioning as a second photodiode. When the first PN junction is shunted, the photoelectric semiconductor device shows a spectral sensitivity which is reduced in the longer wavelength zone. Contrarily, when the second PN junction is shunted, the photoelectric semiconductor device shows the spectral sensitivity which is reduced in the shorter wavelength zone.
    Type: Grant
    Filed: July 24, 1979
    Date of Patent: March 2, 1982
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Toshihumi Yoshikawa, Zempei Tani, Akira Aso, Hitoshi Kawanabe
  • Patent number: 4309604
    Abstract: Disclosed is a solid state wavelength detection system responding to output signals derived from a photoelectric semiconductor device. The photoelectric semiconductor device comprise at least two PN junctions formed at different depth from the surface of the semiconductor substrate. A deeper PN junction develops an output signal related to longer wavelength component of the light impinging thereon. A shallower PN junction develops an output signal related to shorter wavelength component of the impinging light. These two output signals are logarithmically compressed and compared with each other. Difference of the logarithmically compressed output signals represents the wavelength information of the impinging light.
    Type: Grant
    Filed: July 24, 1979
    Date of Patent: January 5, 1982
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Toshihumi Yoshikawa, Zempei Tani, Akira Aso, Hitoshi Kawanabe