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. 17, 1979
Filed:
Nov. 14, 1977
Fuji Photo Optical Co., Ltd., Omiya, JP;
Abstract
A zoom lens system in accordance with this invention is composed of a first fixed lens group, a first movable lens group, a second movable lens group and a second fixed lens group arranged in this order from front to rear, wherein a stop is are located at the center of the whole lens system and the first fixed lens group and the second fixed lens group consist of the same lens elements and located symmetrically with respect to the stop, and similarly the first movable lens group and the second movable lens group consist of the same lens elements and are located symmetrically with respect to the stop. The first movable lens and the second movable lens are asymmetrically moved with respect to the stop in accordance with the location of the whole lens system that is changed to vary the magnification, whereby the distortion and the focus shift caused by the field curvature fluctuation are eliminated throughout the variable range of magnification. Further, the zoom lens system in accordance with this invention is characterized in that the power of the lens groups and the lens elements is designed to make the whole lens system compact in size.