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:
Apr. 25, 1978
Filed:
Aug. 23, 1976
Applicant:
Inventors:
Arthur Cox, Park Ridge, IL (US);
Walter R Linke, Chicago, IL (US);
Assignee:
Bell & Howell Company, Chicago, IL (US);
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G02B / ;
U.S. Cl.
CPC ...
350 54 ; 350189 ;
Abstract
A chromatically neutral viewfinder optical system of positive forward and rearward elements and including therebetween a substantially zero power doublet which neutralizes chromatic errors generated by the positive elements.