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:
Mar. 27, 1984
Filed:
Aug. 07, 1981
Hidekazu Okajima, Tokyo, JP;
Sadahiko Tsuji, Kanagawa, JP;
Canon Kabushiki Kaisha, , JP;
Abstract
In the disclosed zoom lens structure, the zoom system forms an optical axis and includes a focusing lens group, a variator lens group, and an image forming lens group. A cam arrangement serves for moving the focusing lens group along the optical axis while a zooming arrangement serves to displace the variator lens group along the optical axis to adjust the focal length of the system. A compensating arrangement rotates the focusing lens group while simultaneously moving it together with the variator lens group along the optical axis to compensate the focusing of the system. In one embodiment, the cam arrangement forms a first cam range for focusing in a normal range and a second cam range for macrofocusing. Here, the zooming arrangement defines a predetermined variator operating range and a predetermined macrophotography position with the variator lens group and the focusing lens group connected to each other only in the macrophotography position to move along the optical axis in the second cam range.