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:
Mar. 16, 2010
Filed:
May. 13, 2008
Yoshihito Souma, Sakai, JP;
Yoshihito Souma, Sakai, JP;
Konica Minolta Opto, Inc., Hachioji-shi, JP;
Abstract
A zoom optical system at least includes in the order from an object side: a first lens group having a positive optical power; a second lens group having a negative optical power; and a third lens group having a positive optical power. In zooming from a wide angle end to a telephoto end, a distance between the first lens group and the second lens group is increased, and a distance between the second lens group and the third lens group is decreased. The first lens group includes at least one negative lens element, and the second lens group includes a negative lens element closest to the object side, with a lens surface of the negative lens element being concave toward an image side. The zoom optical system satisfies the following conditional expressions (1) and (2):vd<30  (1)50>vd>30  (2)where vdrepresents the Abbe number of the negative lens element closest to the object side in the second lens group, and vdrepresents an Abbe number of a negative lens element, or an average Abbe number of negative lens elements in the first lens group.