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. 20, 1990
Filed:
Mar. 20, 1989
Masashi Takamura, Tokyo, JP;
Kiyotaka Kobayashi, Tokyo, JP;
Toshio Yoshida, Saitama, JP;
Masao Shoji, Saitama, JP;
Masayoshi Hirai, Saitama, JP;
Tetuo Nishizawa, Saitama, JP;
Fuji Photo Film Co., Ltd., Kanagawa, JP;
Abstract
A drive mechanism for a zoom lens system consisting of first and second lens groups has a movable lens barrel fixedly holding the first lens and cam structure consisting of a cam member provided on the second lens group and a cam follower member on the movable lens barrel. The movable lens barrel moves forward or rearward to shift the second lens group forward or rearward relative to the first lens group along the optical axis of the zoom lens system via the cam member so as to continuously change the focal length of the zoom lens system. The cam member is mounted on the movable lens barrel to change the curve of the cam surface relative to the cam follower member only in a middle focal length range.