Patents by Inventor Sinichiro Kawamura

Sinichiro Kawamura 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).

  • Dynamic speaker
    Patent number: 4438297
    Abstract: A plurality of nodes of split vibration of a diaphragm are driven by a plurality of voice coils to prevent split vibration of the diaphragm. The voice coils are inserted between three or more layers of magnetic poles respectively and driven by a magnetic circuit including a plurality of magnets magnetized in the same direction as the vibration of the voice coils.
    Type: Grant
    Filed: November 24, 1981
    Date of Patent: March 20, 1984
    Assignee: Hitachi, Ltd.
    Inventor: Sinichiro Kawamura