Patents by Inventor Tetsurou Ikegaki

Tetsurou Ikegaki 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).

  • Optical data recording system and method of production of recording medium
    Patent number: 4876133
    Abstract: A transparent substrate and a method of producing the same suitable especially for an optical system for an optical data recording medium using a linearly polarized light as a data reading light such as a magneto-optical recording medium drive unit and an optical data recording medium for reading data using a linearly polarized light.
    Type: Grant
    Filed: November 12, 1987
    Date of Patent: October 24, 1989
    Assignee: Hitachi Maxell, Ltd.
    Inventors: Toshinori Sugiyama, Tetsurou Ikegaki, Mitsuru Shimizu, Yoshitane Tuburaya
  • Information recording disc
    Patent number: 4733388
    Abstract: An information recording disc is provided with a magnetic attracting member in the form of metal piece or magnetic material which serves for attracting a disc member for recording, in particular, for optical recording and reproducing of information, to a spindle of a recording and reproducing apparatus. The magnetic attracting member is held in the space of a holder which is fixedly secured to the disc without the magnetic attracting member being fixedly secured to the disc. This arrangement enables a magnetic clamping of the disc member which provides for a decrease of retardation and is suitable for miniaturization of the apparatus.
    Type: Grant
    Filed: August 8, 1986
    Date of Patent: March 22, 1988
    Assignees: Hitachi Maxell, Ltd., Hitachi, Ltd.
    Inventors: Nobuyuki Fujimoto, Shinichi Abe, Yoshito Tsunoda, Kazuo Shigematsu, Yasunori Kanazawa, Toshinori Sugiyama, Tetsurou Ikegaki
  • Optical data recording system and method of production of recording medium
    Patent number: RE37719
    Abstract: A transparent substrate and a method of producing the same suitable especially for an optical system for an optical data recording medium using a linearly polarized light as a data reading light such as magneto-optical recording medium drive unit and an optical data recording medium for reading data using a linearly polarized light.
    Type: Grant
    Filed: June 21, 1994
    Date of Patent: May 28, 2002
    Inventors: Toshinori Sugiyama, Tetsurou Ikegaki, Mitsuru Shimizu, Yoshitane Tuburaya