Patents by Inventor Yoichi Umegaki

Yoichi Umegaki 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).

  • Projection lens
    Patent number: 4770513
    Abstract: A projection lens for projecting an image onto a screen includes, in succession from the screen side, a first lens component having a positive refractive power, a second lens component having a positive refractive power and whose both lens surfaces are convex surfaces, a third lens component of meniscus shape having its convex surface facing the screen side, and a fourth lens component having a negative refractive power and whose surface which is adjacent to the screen is a concave surface.
    Type: Grant
    Filed: October 29, 1986
    Date of Patent: September 13, 1988
    Assignee: Nippon Kogaku K. K.
    Inventors: Daijiro Fujie, Yoichi Umegaki