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:
Nov. 15, 1977
Filed:
Jan. 02, 1976
Bruce K Johnson, Andover, MA (US);
Irving Laskin, Sharon, MA (US);
George D Whiteside, Lexington, MA (US);
Polaroid Corporation, Cambridge, MA (US);
Abstract
An exposure control system for photographic apparatus having a shutter-diaphragm mechanism for regulating the exposure aperture and the exposure interval under both ambient and flash illumination conditions having a blade arrangement which when driven in an opening direction provides enlarging aperture values in a tracking relation defining both a taking aperture and a photocell aperture. The latter being specially configured to initially provide relatively small aperture values necessary for proper flash exposure at near subject distances includes a pair of blade openings wherein the leading portion of one opening is a segment of short length as measured along the axis of diaphragm movement so that, when it is in overlapping arrangement to the leading edge of the other opening, very small aperture values result.