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:
Oct. 23, 2007
Filed:
Aug. 19, 2005
Takumi Matsui, Hachioji, JP;
Takumi Matsui, Hachioji, JP;
Konica Minolta Opto, Inc., Tokyo, JP;
Abstract
A zoom lens sequentially includes, along an optical axis from the object (to be imaged) side, a first lens group which has positive refracting power and is always fixed at a position in the optical axis direction in zooming and focusing, a second lens group having negative refracting power, a third lens group having positive refracting power, and a fourth lens group having positive refracting power. Zooming is performed by moving at least the second lens group and fourth lens group. Focusing is performed by moving at least the fourth lens group. The first lens group includes an optical element having an effect of bending the optical path of a light beam and satisfies the following conditional expression:2.0<1/<4.5where f1 is the focal length of the first lens group and fw is the focal length of the zoom lens at the wide-angle end.