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:
Dec. 22, 1981
Filed:
Dec. 03, 1979
Atsushi Someya, Machida, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
In the disclosed zoom lens of the mechanical compensation type, a first movable lens group, a second movable lens group, a third movable lens group and a fixed lens group are located in sequence from the object end. The first, second and third lens groups are simultaneously moved along the optical axis independently of each so as to change the focal length. The first movable lens group is placed closer to the image at the end of the wide angle position rather than at the end of the telephoto position, while during zooming, the axial movement of the first movable lens from the extreme wide angle position to the extreme telephoto position is smaller than that of the third movable lens group. On the other hand, during focusing, the second and the third lens groups are fixed, while the first movable lens group is moved.