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. 08, 1978
Filed:
Jan. 03, 1977
Applicant:
Inventors:
R Calvin Owen, Jr, Acton, MA (US);
William T Plummer, Concord, MA (US);
Assignee:
Polaroid Corporation, Cambridge, MA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G02B / ; G02B / ;
U.S. Cl.
CPC ...
350189 ; 3501 / ; 350226 ;
Abstract
A multi-element photographic lens has a strongly aspheric surface formed on a strong lens element that is movable relative to the other elements along a common optical axis. The aspheric surface corrects at least the lower order aberrations contributed by the movable element thereby allowing the movement to focus the lens over a wide focus scale or object distance. Preferably, the elements are formed of plastic, the movable element is a front element, and at least one other aspheric surface is formed on a lens element.