Patents by Inventor Takamasa Sakai

Takamasa Sakai 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).

  • Sputtering apparatus
    Patent number: 4412906
    Abstract: A sputtering apparatus includes a target and a substrate holder respectively supported in a lower portion and an upper portion of a vacuum chamber, a gas jet opening located near the upper surface of the target, and gas withdrawal conduits located near the substrate holder, so that by supplying a gas to the vacuum chamber through the gas jet opening, the gas pressure in the chamber gradually decreases from the region near the target to the region near the substrate holder.
    Type: Grant
    Filed: December 21, 1981
    Date of Patent: November 1, 1983
    Assignee: Clarion Co., Ltd.
    Inventors: Yasuhiko Sato, Takamasa Sakai, Shoichi Minagawa
  • Surface-acoustic-wave device
    Patent number: 4365216
    Abstract: A surface-acoustic-wave device wherein a plurality of metal strips (S) are provided on a propagation path of surface acoustic wave which is formed in a laminate comprised of a piezoelectric layer (23) and a semiconductor (1), the metal strips are extended onto the semiconductor outside the propagation path of surface acoustic wave, and depletion layer capacitance non-linearity created on the semiconductor surface at a region where the metal strips are extended is used as a main factor of a parametric interaction.
    Type: Grant
    Filed: January 7, 1981
    Date of Patent: December 21, 1982
    Assignee: Clarion Co., Ltd.
    Inventors: Shoichi Minagawa, Takeshi Okamoto, Takamasa Sakai
  • Surface-acoustic-wave device
    Patent number: 4357553
    Abstract: A surface-acoustic-wave device has a laminate formed of a semiconductor and a piezoelectric layer and a depletion layer control means locally provided at an interface portion of the semiconductor and said piezoelectric layer, wherein a parametric interaction is caused at a region other than an area where the depletion layer control means is provided and a depletion layer capacitance is controlled by applying a DC bias voltage and a pumping voltage to the depletion layer control means.
    Type: Grant
    Filed: August 14, 1980
    Date of Patent: November 2, 1982
    Assignee: Clarion Co., Ltd.
    Inventors: Shoichi Minagawa, Takamasa Sakai, Takeshi Okamoto, Morihiro Niimi