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:
Feb. 26, 2002
Filed:
Mar. 29, 2000
Takashi Tanaka, Kawagoe, JP;
Fuji Photo Optical Co., Ltd., Omiya, JP;
Abstract
A three-group zoom lens of negative, positive, and positive refractive power, in order from the object side. The first lens group is formed of two lens elements of negative and positive refractive power, respectively, the second lens group includes an aperture stop on its object side, and at least one surface in each of these lens groups is aspherical. When zooming from the wide-angle end to the telephoto end, the distance between the first lens group and the second lens group decreases and both the second and the third lens groups move toward the object side. When changing the focus from an object at an infinite distance to a nearby object the position of the third lens group is shifted. When focused on an object at infinity, the distance between the second lens group and the third lens group is kept substantially constant when zooming from the wide-angle end to the telephoto end. The zoom lens has a zoom ratio of 2.5, provides a high-speed focusing, is compact, and has aberrations that are well-corrected so as to provide a high quality image as a result of satisfying specified conditions.