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. 19, 1996
Filed:
Oct. 19, 1994
Minoru Kuwana, Osaka, JP;
Masaaki Miyano, Sakai, JP;
Masayuki Miyazawa, Kawachinagano, JP;
Masayuki Ueyama, Takarazuka, JP;
Shinichi Suzuki, Izumiootsu, JP;
Minolta Co., Ltd., Osaka, JP;
Abstract
A zoom lens barrel based on the vari-focal optical system includes a zoom cam ring which is supported only rotatably about the optical axis and a focus cam ring which is supported movably only in the axial direction both fitted on a fixed tube inside a lens barrel. For the alteration of the lens focal length, the zoom cam ring is turned to carry out zooming, and for the focusing of an object, the focus cam ring is moved in the axial direction to carry out focusing, thereby preventing the interference between zooming and focusing caused by the movement of the lens sets. A drive mechanism based on a piezo-electric element is used to move the focus cam ring in the axial direction, thereby simplifying the structure and reducing the weight.