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, 1992
Filed:
Sep. 10, 1990
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
In the disclosed zoom lens three or more zoom components are located on the image side of a stationary component which is stationary during both focusing and zooming. The three or more zoom components are moved during zooming and are provided into a front portion which is moved for focusing, and a rear portion which remains stationary during focusing. The front focusing portion includes at least two components which move together when focusing, but when zooming move relative to each other so as to change the focal length or power of the front portion. This has the advantageous effect of reducing the difference between the amount the front portion needs to move for focusing at the wide angle position and at telephoto position.