Patents by Inventor Takeo Yokoyama

Takeo Yokoyama 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: 4143472
    Abstract: A display device is disclosed which employs a magnetic panel. The magnetic panel is formed by two oppositely arranged substrates at least one of which is transparent or semi-transparent. The space between the two substrates is filled with a dispersing liquid having a yielding value higher than 5 dyne/cm.sup.2. The dispersing liquid is prepared with fine magnetic grains, a coloring agent, a dispersing medium, and a fine grain thickener. Preferably, a multi-cell structure is provided in the space between the two substrates and the substrates are sealed to the multi-cell structure to form a plurality of independent display cells. A displaying magnet in the form of a pen is used to form a display by causing the fine magnetic grains to migrate to the front of the magnetic panel. An erasing magnet is slidably disposed at the rear of the magnetic panel.
    Type: Grant
    Filed: December 29, 1977
    Date of Patent: March 13, 1979
    Assignee: Pilot Man-Nen Hitsu Kabushiki Kaisha
    Inventors: Yasuzo Murata, Takeo Yokoyama, Hiroshi Murata