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. 24, 2009
Filed:
Dec. 30, 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 front lens group having negative refracting power at a wide-angle end and a rear lens group having positive refracting power at the wide-angle end. The front lens group comprises, in order from the object side, a first lens group of positive refracting power and a second lens group of negative refracting power, and the rear lens group comprises, in order from the object side, a third lens group of positive refracting power and a fourth lens group of positive refracting power. There is an aperture stop interposed between the lens surface located in, and nearest to the object side of, the second lens group and the lens surface located in, and nearest to the image size of, the third 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 wide, the spacing between the second lens group and the third lens group becomes narrow, the spacing between the third lens group and the fourth lens group changes, and an F-number grows greatest when the aperture stop is open in the course of zooming from the wide-angle end to the telephoto end.