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:
Oct. 27, 1987
Filed:
Jan. 09, 1984
Applicant:
Inventor:
Sadao Okudaira, Tokyo, JP;
Assignee:
Asahi Kogaku Kogyo Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G02B / ;
U.S. Cl.
CPC ...
350464 ;
Abstract
A photographic lens with a large aperture ratio comprises a plurality of lens elements brighter than F 1.5 and having a total covering power of at least 40.degree., with at least one of the lens elements being capable of passing an entire luminous flux focusing on a center of an image plane through at least 80 percent of a lens aperture thereof, and given a monotonous refractive index variation in the direction of an optical axis of the lens.