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:
Oct. 28, 2003
Filed:
Aug. 24, 2001
Ryo Yamasaki, Kanagawa, JP;
Go Tokura, Kanagawa, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
Disclosed is a focus detecting device consisting mainly of a light receiving sensor, a reflecting mirror, a first detection circuit, and a focus detection circuit. The light receiving sensor has a plurality of photoelectric converters. The reflecting mirror is movable between a first position at which the reflecting mirror reflects light that comes from an objective, and routes the light to the light receiving sensor, and a second position at which the reflecting mirror recedes from the path of the light coming from the objective. The reflecting mirror has a member that helps form light distributions in a predetermined field on the light receiving sensor. Moreover, the reflecting mirror makes a return from the first position to the second position or vice versa. The first detection circuit detects a change in the light distributions formed in the predetermined field on the light receiving sensor which is observed between before and after the reflecting mirror makes a return. The focus detection circuit detects the focused state of the objective using a light reception signal produced in a field other than the predetermined field on the light receiving sensor and a detection value produced by the first detection circuit. Herein, the focus detecting device is incorporated in a camera.