Patents by Inventor Sadao Mizumo

Sadao Mizumo 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 head
    Patent number: RE37185
    Abstract: In an optical disc recording-reproducing apparatus using a standard optical disc enclosed in a cartridge, and optical plate for correcting various aberrations generated by a focusing lens is comprised therein in order to allow use of a double recording optical disc enclosed in the standard cartridge of the same size, the optical plate is placed in front of a focusing lens when the double recording optical disc is used, and is removed from the front of the focusing lens when the standard optical disc is used.
    Type: Grant
    Filed: July 10, 1997
    Date of Patent: May 22, 2001
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Isao Satoh, Sadao Mizumo, Noboru Itoh