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. 10, 1976
Filed:
Jan. 25, 1974
Toshinobu Ogura, Tondabayashi, JA;
Akiyoshi Nakamura, Sakai, JA;
Minolta Camera Kabushiki Kaisha, Osaka, JA;
Abstract
A retro-focus type wide angle lens system comprises a negative first component located on the object side and including at least one negative meniscus lens; a positive intermediate second component consisting of one or two lens groups including at least one biconvex lens group and a rear third component which includes of four consecutive lenses including, in order, a positive meniscus first lens having a rear convex surface, a biconcave second lens, a positive meniscus third lens having a rear convex surface and a fourth positive lens; whereby the back focus of the total lens system is longer than the focal length, and satisfying the following conditions: