Patents by Inventor Yasuyoshi Tago

Yasuyoshi Tago 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).

  • Plastic multifocal point spherical lens
    Patent number: 4944584
    Abstract: A plastic multifocal point spherical lens comprising a unitary structure of (A) a first synthetic resin layer having a fixed refractive index, (B) a second synthetic resin layer having a substantially fixed refractive index different from the refractive index of the first synthetic resin layer, and (C) a third synthetic resin layer existing between the first synthetic resin layer and the second synthetic resin layer and having a refractive index gradient varying continuously from the refractive index of the first synthetic resin layer to that of the second synthetic resin layer, part of the second synthetic resin layer and part of the third synthetic resin layer together being recessed into the first synthetic resin layer, and the second synthetic resin layer being thicker at the recessed part than the rest.
    Type: Grant
    Filed: February 23, 1989
    Date of Patent: July 31, 1990
    Assignee: Nippon Sheet Glass Co., Ltd.
    Inventors: Koichi Maeda, Akio Takigawa, Yasuyoshi Tago, Motoaki Yoshida