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:
Aug. 17, 1976
Filed:
Apr. 19, 1974
Applicant:
Inventor:
Ellis I Betensky, Toronto, CA;
Assignee:
Ponder & Best, Inc., Santa Monica, CA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G02B / ;
U.S. Cl.
CPC ...
350184 ; 350176 ; 350177 ; 350187 ;
Abstract
A lens having an equivalent focal length variable between predetermined limits where the lower limit is less than the diagonal of the image frame and where the lens comprises four lens groups of positive, negative, negative and positive powers, respectively, and the first three groups mounted from the object end are movable in unequal relationship to vary the focal length while all four groups are axially movable in fixed relation to each other to focus the lens.