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. 06, 1979
Filed:
Mar. 29, 1978
Koichi Kobayashi, Tokyo, JP;
Asahi Kogaku Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
A wide angle retrofocus lens system comprises, in order from the object side to the image side, a first negative meniscus lens having a convex surface facing the object, a second positive double convex lens, a third negative meniscus lens having a convex surface facing the object, a fourth either positive or negative meniscus lens having a concave surface facing the object, a fifth either positive meniscus lens having a convex surface facing the object or positive double convex lens, a sixth negative lens, a seventh positive meniscus lens having a concave surface facing the object, and an eighth lens unit comprising a double concave lens on the object side and a double convex lens on the image side cemented together to form a positive lens. The overall lens system satisfies the following conditions: ##EQU1## wherein: f is the focal distance of the overall lens system,