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:
Jan. 28, 1986
Filed:
Apr. 05, 1984
Hirohumi Matsuo, Tokyo, JP;
Asahi Kogaku Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
A retro-focus type wide-angle lens having an aperture ratio of 1:2, an angle of view of about .+-.42.degree., and a back focus about 1.5 times the focal length comprises only nine component lenses. The first lens disposed nearest to the object side is a positive meniscus. The second and third lenses are each a negative meniscus. The fourth lens is a positive lens. One of the fifth and sixth lens is a double-convex lens, the other being a positive meniscus. The seventh, eighth, and ninth lenses are a double-concave lens, a positive meniscus, and a double-convex lens, respectively. The sixth and seventh lenses are cemented together. The wide-angle lens satisfies the following conditions: