Patents by Inventor Kae Shijo

Kae Shijo 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).

  • Camera-attachment lens system
    Patent number: 6690518
    Abstract: A camera-attachment lens system includes a positive condenser lens system and a positive image-forming lens system, and satisfies the following conditions: 1.5<fa/fco<2.4  (1) 0.08<DO/fa<0.16  (2) 1.65<Nco  (3) wherein fa: the combined focal length of the condenser lens system and the image-forming lens system; fco: the focal length of the condenser lens system; DO: the distance from the image-forming plane of the objective optical system to the most objective-optical-system side surface of the condenser lens system; and Nco: the refractive index of the condenser lens system.
    Type: Grant
    Filed: December 28, 2001
    Date of Patent: February 10, 2004
    Assignee: Pentax Corporation
    Inventors: Kae Shijo, Shinichiro Ishii, Takayuki Ito
  • Camera-attachment lens system
    Publication number: 20030090811
    Abstract: A camera-attachment lens system includes a positive condenser lens system and a positive image-forming lens system, and satisfies the following conditions:
    Type: Application
    Filed: December 28, 2001
    Publication date: May 15, 2003
    Applicant: ASAHI KOGAKU KOGYO KABUSHIKI KAISHA
    Inventors: Kae Shijo, Shinichiro Ishii, Takayuki Ito
  • Optical system of a composite camera
    Patent number: 6392820
    Abstract: An optical system of a composite camera including a first image-forming optical system, a second image-forming optical system, and a condenser lens group, which includes two or more lens elements, or includes a single lens element on which at least one aspherical surface is formed; and at any image height on the equivalent image plane, the following condition is satisfied: &Dgr;&thgr;Pmax−&Dgr;&thgr;Pmin<2° . . .
    Type: Grant
    Filed: April 6, 2000
    Date of Patent: May 21, 2002
    Assignee: Asahi Kogaku Kogyo Kabushiki Kaisha
    Inventors: Kae Shijo, Shinichiro Ishii, Takayuki Ito