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:
Jun. 26, 1979
Filed:
Dec. 15, 1976
Applicant:
Inventors:
Ellis I Betensky, Toronto, CA;
John A Lawson, Dayton, OH (US);
Assignee:
Vivitar Corporation, Santa Monica, CA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01B / ;
U.S. Cl.
CPC ...
350176 ; 350184 ;
Abstract
A zoom lens having a wide field angle and two movable groupings to vary the equivalent focal length, the front grouping comprising a front positive group, a negative group comprising a plurality of negative elements, and a rear positive group. In zooming the rear grouping moves forward to increase the equivalent focal length while the front grouping moves backward to maintain the image plane. The front grouping is independently movable for focusing.