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:
Jul. 10, 2012
Filed:
Apr. 02, 2010
Yasuaki Hagiwara, Utsunomiya, JP;
Yasuaki Hagiwara, Utsunomiya, JP;
Canon Kabushiki Kaisha, , JP;
Abstract
The zoom lens with a wide angle of view, a high zoom ratio and high optical performance 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 fourth lens unit having a positive refractive power. The second and fourth lens units are moved on an optical axis for zooming. The second lens unit is constituted by, in order from the object side to the image side, three negative lens elements and one positive lens element. The zoom lens satisfies 0.54<|f2|/√(fw·ft)<0.66, where f2 represents a focal length of the second lens unit, fw and ft represent focal lengths of the entire zoom lens at a wide-angle end and at a telephoto end, respectively.