Patents by Inventor Shinsuke Shikawa

Shinsuke Shikawa 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).

  • Retro-focus type lens and projection-type display apparatus
    Patent number: 5442484
    Abstract: A retro-focus-type lens is provided from a large conjugate side with a first lens group having a negative refracting power, a second lens group having a positive refracting power which is spaced away from the first lens group at an air interval D1, and a third lens group having a positive refracting power. The following conditions are satisfied when focal lengths of the first lens group, the second lens group, the third lens group, and a total lens system are assumed respectively as f1, f2, f3, and f:1.8<D1/f<3.01.1<f2/f3<1.61.5<.vertline.f1.vertline./f<2.3.A projection lens constructed by inserting a mirror in a lens system of thus constructed retro-focus type lens is used in a projection-type display apparatus.
    Type: Grant
    Filed: December 30, 1992
    Date of Patent: August 15, 1995
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Shinsuke Shikawa