Patents by Inventor Toshiyuki Ookuma

Toshiyuki Ookuma 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: 5641578
    Abstract: A black steel sheet having a sufficiently small coating thickness to allow the welding of the steel sheet, and yet exhibiting an excellently black surface. It is a steel sheet having a surface plated with zinc or a zinc alloy, and carrying a chromate film formed on its plated surface, and a black film formed on the chromate film from a composition comprising specific proportions of a thermosetting resin and a black dye, which are both soluble in an organic solvent, and having a sufficiently small thickness. The composition may further contain a solid lubricant, or a granular rust-inhibitive pigment, or both.
    Type: Grant
    Filed: July 10, 1995
    Date of Patent: June 24, 1997
    Assignee: NKK Corporation
    Inventors: Naoto Yoshimi, Masaaki Yamashita, Toshiyuki Ookuma, Tatsuya Miyoshi, Toyofumi Watanabe, Tsutomu Watanabe
  • Patent number: 5609968
    Abstract: A colored steel sheet having a coating thickness which is sufficiently small to permit welding therethrough, and yet exhibiting an excellently colored and lustrous surface. It is a steel sheet having a surface plated with zinc or a zinc alloy, and carrying a chromate film formed on its plated surface, and a colored film formed on the chromate film from a composition comprising specific proportions of a thermosetting resin and a dye, which are both soluble in an organic solvent. The composition may further contain a solid lubricant, or a granular rust-inhibitive pigment, or both. The colored film has a specific range of thickness, and a color other than black.
    Type: Grant
    Filed: May 27, 1994
    Date of Patent: March 11, 1997
    Assignee: NKK Corporation
    Inventors: Naoto Yoshimi, Toyofumi Watanabe, Masaaki Yamashita, Toshiyuki Ookuma, Tatsuya Miyoshi
  • Patent number: 5053652
    Abstract: A semiconductor memory device has a sense amplifier which is constructed with a level shift circuit having an input which senses the change in a data line from an initial precharged level to a level near the vicinity of the supply voltage level which corresponds to data reading amounts from a memory cell during the reading mode of operation of the memory. The level shift circuit, in response to a memory cell reading signals, provides a level shifted outpout to the input terminal of a differential sense amplifier circuit, the level shifted output being in the vicinity of the operating point of the differential sense amplifier circuit. The level shift circuit includes a current amplifier having an output terminal that is formed with a series connecting node of a current amplifying transistor and a current source.
    Type: Grant
    Filed: January 4, 1991
    Date of Patent: October 1, 1991
    Assignee: Hitachi, Ltd.
    Inventors: Yoichi Sato, Masao Mizukami, Toshiyuki Ookuma
  • Patent number: 4984204
    Abstract: A semiconductor memory device has a sense amplifier which is constructed with a level shift circuit having an input which senses the change in a data line from an initial precharged level to a level near the vicinity of the supply voltage level which corresponds to data reading amounts from a memory cell during the reading mode of operation of the memory. The level shift circuit, in response to a memory cell reading signals, provides a level shifted output to the input terminal of a differential sense amplifier circuit, the level shifted output being in the vicinity of the operating point of the differential sense amplifier circuit. The level shift circuit includes a current amplifier having an output terminal that is formed with a series connecting node of a current amplifying transistor and a current source.
    Type: Grant
    Filed: January 30, 1989
    Date of Patent: January 8, 1991
    Assignees: Hitachi, Ltd., Hitachi VLSI Engineering Corp.
    Inventors: Yoichi Sato, Masao Mizukami, Toshiyuki Ookuma