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:
Nov. 03, 1981
Filed:
Jan. 07, 1980
Applicant:
Inventors:
James D Rees, Pittsford, NY (US);
Kenneth W Altfather, Jr, Fairport, NY (US);
William L Lama, Webster, NY (US);
Donna U Ozern, Amherst, NH (US);
Assignee:
Other;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G03B / ;
U.S. Cl.
CPC ...
355 71 ; 350314 ; 354296 ;
Abstract
In an optical system for a multi-magnification copying device, a relative illumination filter is mounted in a fixed position relative to the projection lens with the center on the lens optical axis. The filter provides a radially varying transmission therethrough which compensates for circularly symmetric nonuniformities in the optical system at any magnification.