Patents by Inventor Mitsuyoshi Matsuda

Mitsuyoshi Matsuda 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).

  • Coaxial speaker unit
    Patent number: 4821331
    Abstract: A coaxial speaker includes a low-frequency band speaker diaphragm which supports, at its inner periphery, a dust-proof member for the speaker core, via a step portion located on the diaphragm at this location. The step portion is planar and generally perpendicular to the speaker bobbin, and may be either a continuous ring or a series of discrete steps arrayed circularly.
    Type: Grant
    Filed: June 20, 1988
    Date of Patent: April 11, 1989
    Assignee: Pioneer Electronic Corporation
    Inventors: Fumio Murayama, Mitsuyoshi Matsuda