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:
Feb. 23, 1993
Filed:
Dec. 18, 1991
Applicant:
Inventors:
David L Farrington, Boxborough, MA (US);
Norman D Staller, Beverly, MA (US);
Jon E Van Tassell, Concord, MA (US);
Assignee:
Polaroid Corporation, Cambridge, MA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G03B / ;
U.S. Cl.
CPC ...
354403 ;
Abstract
A simplifed open loop focus control system for a fixed focus lens camera that positions a supplemental lens into the optical path of a fixed focus lens, for relatively remote subjects, in response to a signal representative of subject reflectivity. Inserting such a lens in this manner substantially reduces focus control system complexity while at the same time minimizing the frequency of supplemental lens movement for most exposures which are typically of subjects that are relatively close to the fixed focus lens camera.