Patents by Inventor Ikuo Kayama

Ikuo Kayama 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).

  • Patent number: 4448837
    Abstract: A pressure-sensitive, conductive elastic sheet for use in a graphics digitizing tablet through which various letters or figures can be detected, the characteristics of which are such that the contact pressure is almost constant irrespective of contact area or increases with increasing contact area. The pressure-sensitive sheet according to the present invention comprises a silicon rubber in which a number of coarse, ferromagnetic, conductive metal particles with a diameter of 30 to 150 micron are mixed with a number of fine, ferromagnetic, conductive metal particles with a diameter of 10 micron or less or 50 micron or less at a predetermined proportion in such a manner that the coarse particles are aligned vertically through the interior thereof and the fine particles are dispersed near at least one surface thereof. To properly align the particles, the sheet is allowed to set within a uniform magnetic field.
    Type: Grant
    Filed: July 19, 1982
    Date of Patent: May 15, 1984
    Assignee: Oki Densen Kabushiki Kaisha
    Inventors: Eiichi Ikeda, Ikuo Kayama, Masahiro Izaki