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:
Jan. 27, 1998
Filed:
Jan. 17, 1996
Hitoshi Mukaiya, Kanagawa-ken, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A zoom lens of the rear focus type comprising, in order from an object side to an image side, a first lens unit of positive refractive power, a second lens unit of negative refractive power, a third lens unit of positive refractive power and a fourth lens unit of positive refractive power, wherein the second lens unit and the fourth lens unit are moved to effect zooming and the fourth lens unit is moved to effect focusing, wherein the third lens unit includes a positive first lens and a negative second lens of meniscus form convex toward the image side, and the fourth lens unit includes a negative first lens of meniscus form convex toward the object side and a positive second lens, and wherein an aspheric surface is applied to the third lens unit or the fourth lens unit.