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:
Apr. 03, 2007
Filed:
Aug. 30, 2005
Yasutaka Kashiki, Hino, JP;
Yasutaka Kashiki, Hino, JP;
Olympus Corporation, Tokyo, JP;
Abstract
The invention relates to a wide-angle zoom lens system easy to ensure telecentricity particularly suited for digital single-lens reflex cameras. The wide-angle zoom lens system comprises a first group Gof negative power, a second group Gof positive power and a third group Gof positive power. Upon zooming from a wide-angle end to a telephoto end, at least the first group Gand the second group Gmove such that a spacing between the first group Gand the second group Gbecomes narrow and a spacing between the second group Gand the third group Gbecomes wide. The first group Gcomprises, in order from its object side, a first lens subgroup SGof negative refracting power and a second lens subgroup SGof negative refracting power. Upon focusing from a far object point to a near object point, the first lens subgroup SGand the second lens subgroup SGmove toward the object side with a narrowing spacing between them.