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:
Mar. 16, 1982
Filed:
Feb. 06, 1980
Applicant:
Inventors:
Harumi Aoki, Kiyose, JP;
Yoshio Sawada, Tokyo, JP;
Assignee:
Asahi Kogaku Kogyo Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G03B / ; G03B / ;
U.S. Cl.
CPC ...
354 25 ; 354 53 ; 354198 ; 354289 ; 250201 ;
Abstract
An automatic focus detecting and indicating device for an camera in which a contrast signal is coupled through first and second analog switches directly to a difference circuit and through a peak hold circuit, respectively. A third analog switch is coupled so as to discharge the value stored in the peak hold circuit. The three switches are operated by a control circuit which in turn operates in accordance with the direction of movement of the lens and the detection of a rising edge of the contrast signal so as to prevent the generation of a false focus signal at other than the point of true focus.