Patents by Inventor Keishi Honta

Keishi Honta 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).

  • Achromatic lens for ultraviolet rays
    Patent number: 5028967
    Abstract: An achromatic lens for ultraviolet rays constituted by (A) high-purity silica glass having a purity of 99.9% or more, or fluorine-containing, high-purity silica glass having a purity of 99.9% or more; and (B) silica glass containing germanium dioxide or silica glass containing germanium dioxide and boron oxide.
    Type: Grant
    Filed: March 16, 1990
    Date of Patent: July 2, 1991
    Assignee: Tosoh Corporation
    Inventors: Nobusuke Yamada, Koji Tsukuma, Tetsuo Fujii, Hideaki Segawa, Shinichi Kondo, Keishi Honta
  • Method of producing uniform silica glass block
    Patent number: 4938788
    Abstract: A method of producing a uniform silica glass block comprising using silica powder as a raw material, and treating it at high temperature and pressure by a hot press and/or a hot isostatic press in vacuum or in an inert gas atmosphere, preferably with a capsule of silica glass or a high-melting point metal. By conducting calcination in fluorine, chlorine or their compound gas and then in oxygen, the OH group content of the silica glass can be reduced dramatically.
    Type: Grant
    Filed: December 28, 1988
    Date of Patent: July 3, 1990
    Assignee: Tosoh Corporation
    Inventors: Hideaki Segawa, Koji Tsukuma, Shinichi Kondo, Keishi Honta