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:
Sep. 27, 2016
Filed:
Dec. 03, 2014
Canon Kabushiki Kaisha, Tokyo, JP;
Norihiro Nanba, Utsunomiya, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A zoom lens includes, in order from an object side to an image side, a first lens unit having positive refractive power, a second lens unit having negative refractive power, and a rear lens group having a plurality of lens units at least one of which has positive refractive power. The distance between the first lens unit and the second lens unit is greater at a telephoto end than at a wide angle end. The first lens unit includes a positive lens and a negative lens. The rear lens group includes a lens unit R comprising a positive lens and a negative lens. The lens unit R has the highest zoom ratio among the lens units included in the rear lens group. The materials of the positive and negative lenses included in the first lens unit and in the lens unit R are selected appropriately based on predetermined mathematical conditions.