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. 22, 2009
Filed:
Jun. 05, 2008
Yoshihito Souma, Sakai, JP;
Yoshihito Souma, Sakai, JP;
Konica Minolta Opto, Inc., Hachioji-shi, JP;
Abstract
A zoom lens for forming an optical image of an object on a sensing surface of an image sensor at a variable magnification has first, second, third, fourth and fifth lens groups with positive-negative-positive-negative-positive zoom arrangement. Between the second lens group and the fourth lens group, an optical aperture stop is located. The fourth lens group is composed of one negative lens element having at least one aspherical surface and having a paraxial radius of curvature of an image side surface smaller than a paraxial radius of curvature of an object side surface, and satisfies conditional formula −1.15<f4/√{square root over (fw·ft)}<−0.5 (where f4 represents a focal length of the fourth lens group, fw represents a focal length of an entire system at a wide-angle end, and ft represents a focal length of the entire system at a telephoto end).