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:
Dec. 08, 2009
Filed:
Nov. 05, 2008
Hiroshi Saruwatari, Utsunomiya, JP;
Hiroshi Saruwatari, 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 and configured to move along an optical axis during zooming, a second lens unit having a negative refractive power and configured to move with a locus convex towards the image side during zooming, a third lens unit having a positive refractive power, and a fourth lens unit having a negative refractive power. The first lens unit is located closer to the object side at a telephoto end than at a wide-angle end and the second lens unit is located closer to the image side at the telephoto end than at the wide-angle end. A focal length of the second lens unit (f2), a focal length of the zoom lens at the wide-angle end (fw), and a focal length of the zoom lens at the telephoto end (ft) are appropriately set.