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:
Aug. 01, 1978
Filed:
Feb. 14, 1977
Applicant:
Inventors:
Assignee:
Canon Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G03B / ; G03B / ;
U.S. Cl.
CPC ...
354 25 ; 354 31 ; 354 54 ; 354201 ;
Abstract
In an automatic focusing screen unit transparent photoelectric transducing means at a central portion of the image receiving surface area of a glass plate are capable of generating an output signal commensurate with the sharpness of an image formed thereon by an objective lens of a camera. An electrical circuit for processing the output signal of the transducing means produces an output during sharp focus. In a preferred embodiment, this circuit is constructed in the form of an integrated circuit chip for incorporation in the unit together with indicating means responsive to the output signal of the circuit for indicating a sharp focus condition.