Patents by Inventor Takehiko Kotoh

Takehiko Kotoh 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).

  • Method of manufacturing an electret device
    Patent number: 4356049
    Abstract: A method of manufacturing an electret device which comprises the step of causing a pressure deformation jig whose surface is provided with numerous minute convex and concave regions to abut against the surface of a raw dielectric material for an electret and later be removed therefrom, thereby forming minute stretched and contracted region on the surface of said dielectric material.
    Type: Grant
    Filed: March 10, 1981
    Date of Patent: October 26, 1982
    Assignee: Tokyo Shibaura Denki Kabushiki Kaisha
    Inventors: Sakae Tamura, Hiromi Yoshida, Takehiko Kotoh, Masami Kobayashi