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:
Jun. 02, 1998
Filed:
Nov. 22, 1994
Chiaki Terasawa, Kanagawa-ken, JP;
Jun Hosoya, Kanagawa-ken, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A zoom lens comprising, from front to rear, a first lens unit of positive refractive power, a second lens unit of negative refractive power for varying the focal length, a third lens unit of positive or negative refractive power for compensating for the image shift with zooming, an aperture stop and a fourth lens unit having the image forming function and stationary during zooming, wherein the first lens unit has a front lens sub-unit of negative refractive power, a first lens sub-unit of positive refractive power and a second lens sub-unit of positive refractive power, and wherein during focusing from an infinitely distant object to an object at the minimum distance, at least the first and second lens sub-units are axially moved.