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. 05, 2013
Filed:
Apr. 13, 2011
Shinichiro Saito, Utsunomiya, JP;
Nobuyuki Miyazawa, Utsunomiya, JP;
Tomonori Kimura, Utsunomiya, JP;
Shinichiro Saito, Utsunomiya, JP;
Nobuyuki Miyazawa, Utsunomiya, JP;
Tomonori Kimura, 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, a third lens unit having a positive refractive power, and a rear lens unit including one or more lens units. An interval between respective adjacent lens units varies during zooming such that an interval between the first lens unit and the second lens unit is larger at a telephoto end than at a wide-angle end and an interval between the second lens unit and the third lens unit is smaller at the telephoto end than at the wide-angle end. The third lens unit includes at least one negative lens. An Abbe number (νd) and a relative partial dispersion (θgF) of a material of the negative lens are appropriately set based on predetermined conditional expressions.