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. 16, 1991
Filed:
Jun. 22, 1989
Applicant:
Inventors:
Assignee:
Seikosha Co., Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G03B / ; G01C / ;
U.S. Cl.
CPC ...
354403 ; 356-1 ;
Abstract
An active rangefinder for use in a camera. The rangefinder has a light-emitting device, a spot light position detector disposed at a given distance from the light-emitting device, head amplifiers, filters having amplification function, synchronous detectors, integrators, an adder, a subtracter, a microcomputer, and an automatic gain control (AGC). The filters are connected to their respective head amplifiers each having an operational amplifier. The gains of the filters are controlled by the AGC according to the output signals from the synchronous detectors.