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:
Jun. 19, 1990
Filed:
Oct. 05, 1989
Muneharu Sugiura, Tokyo, JP;
Akihisa Horiuchi, Kanagawa, JP;
Hiroyuki Hamano, Kanagawa, JP;
Nobuyoshi Suzuki, Kanagawa, JP;
Hitoshi Mukaiya, Saitama, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A zoom lens comprising, from front to rear, a positive first group for focusing, a negative second group as the variator, a negative third group as the compensator, a positive fourth group and a fifth group as the relay lens, the fourth group in the form of a bi-convex singlet and the fifth group in two parts with a widest spacing therebetween, of which the front part comprises a bi-convex first lens, a negative second lens whose front surface is concave toward front, and a positive third lens whose front surface is of strong curvature, and the rear part comprises a negative lens whose rear surface is concave toward rear, a bi-convex lens and a positive lens whose front surface is of strong curvature, satisfying the following conditions: