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. 06, 2010
Filed:
Dec. 22, 2008
Masashi Hankawa, Hachioji, JP;
Tomoyuki Satori, Kawagoe, JP;
Masashi Hankawa, Hachioji, JP;
Tomoyuki Satori, Kawagoe, JP;
Olympus Imaging Corp., Tokyo, JP;
Abstract
A zoom lens comprises, in order from its object side, a first lens group of positive refracting power, a second lens group of negative refracting power, and a third lens group of positive refracting power located on an image side with respect to the second lens group. Upon zooming from the wide-angle end to the telephoto end, the spacing between the first lens group and the second lens group grows wider at the telephoto end than at the wide-angle end, and the spacing between the second lens group and the third lens group becomes narrower at the telephoto end than at the wide-angle end. The first lens group comprises a negative lens and a positive lens, and the number of the negative lens in the first lens group is only one. At least one positive lens in the first lens group satisfies the following conditions (1) and (2):1.80<ndlp<2.0  (1)50.0<νdlp<70.0  (2)where ndlp is the d-line refractive index of the at least one positive lens in the first lens group, and νdlp is the Abbe constant of the at least one positive lens in the first lens group.