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:
Nov. 21, 2006
Filed:
Jun. 02, 2005
Norihiro Nanba, Tochigi-ken, JP;
Hiroyuki Hamano, Ibaraki-ken, JP;
Norihiro Nanba, Tochigi-ken, JP;
Hiroyuki Hamano, Ibaraki-ken, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A zoom lens system capable of correcting a secondary spectrum is disclosed. The zoom lens system includes a first lens unit with a positive optical power, a second lens unit with a negative optical power, an aperture stop, and a rear lens component including at least one lens unit in an order from an object side to an image side. In the zoom lens system, during zooming from a wide angle end to a telephoto end, an interval between the first lens unit and the second lens unit increases, and an interval between the second lens unit and the aperture stop decreases. Then, a material satisfying the following conditions:νd1n<35θis used for the negative lens in the first lens unit. Herein, νdrepresents an Abbe number, and θgFrepresents a partial dispersion ratio.