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:
Feb. 25, 1992
Filed:
Nov. 29, 1990
Yasunori Imaoka, Yokohama, JP;
Shigeru Oshima, Yokohama, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A zoom lens barrel includes a first and a second lens units simultaneously shifting for zooming along an optical axis; a fixed lens barrel for housing the first and second lens units; a first cam groove formed in the fixed lens barrel so as to control the shift of the first lens unit; and a second cam groove formed in the fixed lens barrel so as to control the shift of the second lens unit. The zoom lens barrel further includes a rotary barrel rotating on the optical axis; a straight groove, extending in the optical axis, formed in the rotary barrel so as to control the shift of the first lens unit; a straight groove, extending in the optical axis, formed in the rotary barrel so as to control the shift of the second lens unit; a first retaining ring which retains the first lens unit, and which has a projection engaged with the first straight groove and the first cam groove; and a second retaining ring which retains the second lens unit, and which has a projection engaged with the second straight groove and the second cam groove.