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:
Feb. 03, 2009
Filed:
Sep. 12, 2007
Rei Iwama, Utsunomiya, JP;
Rei Iwama, Utsunomiya, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A zoom lens includes, in order from an object side to an image side, first, second, and third lens units having negative, positive, and positive refractive power, respectively. The zoom lens performs zooming by varying distances between the lens units. The second lens unit includes a first lens subunit composed of positive and negative lens elements, and a second lens subunit arranged on the image side of the first lens subunit and composed of positive and negative lens elements. The following conditions are satisfied:ν1n<29,ν2n<30,18<ν1−Θ1<35, and26<ν2−ν2<35,where ν1and ν1respectively represent Abbe numbers of materials of the positive and negative lens elements of the first lens subunit, and ν2and ν2respectively represent Abbe numbers of materials of the positive and negative lens elements of the second lens subunit.