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. 17, 1992
Filed:
Aug. 05, 1991
Kiyoshi Fukami, Tokyo, JP;
Jun Hosoya, Kanagawa, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A zoom lens capable of changing the range of variable focal length to another limit, comprising, from front to rear, a zoom section including a variator and a compensator arranged upon zooming movement to vary the focal length in a predetermined range, a diaphragm, and a relay lens section receptive of the afocal light beam from the zoom section to form an image and having a front lens unit and a rear lens unit, the front lens unit being provided with a fixed sub-unit and an interchangeable sub-unit in this order from the front, wherein the interchangeable sub-unit is removed to create a space between the fixed sub-unit and the rear lens unit, into which a range changing lens unit is then inserted, so that the range of variable focal length is changed.