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:
Mar. 26, 2013
Filed:
Aug. 06, 2010
Chiaki Inoue, Utsunomiya, JP;
Tsuyoshi Wakazono, Utsunomiya, JP;
Chiaki Inoue, Utsunomiya, JP;
Tsuyoshi Wakazono, 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 a positive refractive power, a second lens unit having a negative refractive power, an aperture stop, a third lens unit having a positive refractive power, and a rear group including at least one lens unit. During zooming from a wide angle end to a telephoto end, the first and third lens units move to the object side, the second lens unit moves to the image side, and the aperture stop moves to the object side along a convex path. Radii of curvature of object- and image-side lens surfaces of a lens closest to the object side in the second lens unit, focal lengths of the entire zoom lens at the wide angle end and the telephoto end, and focal lengths of the first and second lens units are set properly.