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:
Dec. 17, 1985
Filed:
Sep. 20, 1984
Arthur J Winter, Encino, CA (US);
W. Haking Enterprises Limited, Hong Kong, HK;
Abstract
A film speed correction circuit for electrically controlled cameras having aperture or shutter speed controlled responsively to ambient light sensings from a photosensor features a controllable multi-stage amplifier preferably interposed between the photosensor and the aperture or shutter control means. The amplifier features a plurality of cascaded stages, each stage being operated to two different gain values according to a sensing signal provided thereto, the sensing signals for each stage being derived from coded insulating and conducting areas on the outer surface of the film cassette. Use of active stages interposed between passive attenuating stages substantially eliminates interstage loading and allows the use of standard resistance values to provided proper gain values for each stage.