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:
Mar. 18, 1986
Filed:
May. 18, 1984
Kiyotaka Inadome, Kawasaki, JP;
Nippon Kogaku K. K., Tokyo, JP;
Abstract
A zoom lens having a change-magnification range ranging from wide angle to telephoto comprises, in succession from the object side, first lens group of positive refractive power movable on the optical axis, a second lens group of negative refractive power fixed relative to the image plane at a determined position, a third lens group of negative refractive power movable on the optical axis, and a fourth lens group of positive refractive power movable on the optical axis. The first and fourth lens groups are moved toward the object side in linear fashion to change magnification from the wide angle end to the telephoto end while the third lens group is moved toward the object side at the same time in non-linear fashion to keep the image plane at the determined position.