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:
Sep. 29, 2009
Filed:
Apr. 24, 2008
Koji Hoshi, Yokohama, JP;
Koji Hoshi, Yokohama, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A zoom lens system, in that order from an object side to an image side, includes first to fourth lens units respectively having positive, negative, positive, and positive optical powers. The second and fourth lens units move along an optical axis during zooming. In the zoom lens system, the third lens unit includes a first lens subunit having a negative optical power, and a second lens subunit having a positive optical power, in that order from the object side to the image side. The first lens subunit has no more than a positive lens element and a negative lens element. The second lens subunit has no more than a positive lens element and a negative lens element. Accordingly, the arrangements of the third lens unit and other lens units are properly set.