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:
Jan. 05, 1988
Filed:
Dec. 03, 1984
Applicant:
Inventors:
Assignee:
Canon Kabushiki Kaisha, , US;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01J / ; G01C / ;
U.S. Cl.
CPC ...
250204 ; 356-4 ;
Abstract
A focus detecting device arranged to detect the focusing condition of an objective lens by projecting a light flux from a light source onto an object through the objective lens and by sensing the light flux after it is reflected from the object. The focus detecting device is provided with sensors which produce information necessary for detecting the focal point of the objective lens by sensing the light of the light source reflected by the object. Degradation of the device's detection accuracy due to the eccentrically mounted objective lens is prevented when these sensors are symmetrically arranged relative to a plane containing the optical axis of the objective lens.