The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 23, 1998
Filed:
Dec. 24, 1996
Yasuo Suda, Yokohama, JP;
Keiji Ohtaka, Yokohama, JP;
Keiji Nagata, Yokohama, JP;
Kenichiro Yamashita, Matsudo, JP;
Terutake Kadohara, Yokohama, JP;
Hitoshi Onoda, Yokohama, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A focus detecting apparatus includes an optical unit provided on an image plane side of an objective lens for detecting a focus state of the objective lens, the optical unit forming a plurality of light quantity distributions, a photoelectrical changing unit having a plurality of elements for outputting a relative positional signal between the plurality of light quantity distributions, and a circuit for detecting a focus state of the objective lens. The optical unit includes a reflecting mirror having a light condensing property for reflecting a light beam from the objective lens to form an object image on a predetermined surface, a secondary imaging lens having at least a pair of lenses for causing the object image formed on the predetermined surface to be reimaged on the photoelectrical changing unit and a pair of apertures having aperture portions respectively corresponding to the pair of lenses. When the photoelectrical changing unit is reversedly projected by the secondary imaging lens and the reflecting mirror, the elements corresponding to the direction of arrangement of the pair of apertures of the photoelectrical changing unit are arranged so that a peripheral portion of the elements is not parallel to the center of the arrangement of the elements.