Patents by Inventor Akio Obuchi

Akio Obuchi 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).

  • Speaker diaphragm having flat response curve
    Patent number: 4057694
    Abstract: The nodal circle between the inner and outer concentric portions of an audio speaker diaphragm is positioned so that the ratio of the areas of the inner and outer portions is approximately equal to the ratio of their respective masses, whereby the frequency response curve remains relatively flat and is not affected by first order resonance.
    Type: Grant
    Filed: October 21, 1976
    Date of Patent: November 8, 1977
    Assignee: Pioneer Electronic Corporation
    Inventor: Akio Obuchi