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:
Apr. 28, 1992
Filed:
Apr. 26, 1991
Masaki Higashihara, Kanagawa, JP;
Keiji Ohtaka, Kanagawa, JP;
Kenji Suzuki, Kanagawa, JP;
Takeshi Koyama, Tokyo, JP;
Yasuo Suda, Kanagawa, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A focusing detecting device is disclosed having apparatus for forming object light patterns whose relative position changes in conformity with a focus state of an objective lens. Light flux passes through different areas of an exit pupil of the objective lens, and circuitry receives and photoelectrically converts the light patterns, and detects the focus state of the objective lens on the basis of the photoelectrically converted signal. The focusing apparatus accroding to the present invention a plurality of sets of structures for forming light patterns and means for photoelectrically converting the light patterns which are provided at different distances from the position of the optic axis of the objective lens. Also disclosed are means for making (a) the shapes of the areas of the exit pupil through which the light flux is passed to form the light patterns, or (b) intervals between the centers of gravity of said areas, or (c) both, different between a position in the vicinity of the optic axis of the objective lens, and a position distant therefrom.