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. 20, 1982
Filed:
Jan. 10, 1980
Milton S Dietz, Lexington, MA (US);
Polaroid Corporation, Cambridge, MA (US);
Abstract
Apparatus for automatically varying positioning of an infrared filter relative to a light sensing photocell of an exposure control system having scanning type shutter blades provided with cooperating pairs of primary and secondary apertures, which are displaced between first and second positions to respectively control the passage of light to a film plane and to the photocell, includes an infrared filter cooperating with at least one secondary aperture for blocking transmission of infrared to the photocell when the apertures are positioned for high ambient light conditions and for allowing passage of infrared to the photocell when positioned for low ambient light conditions where flash illumination provides a greater contribution to the exposure.