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. 16, 1976
Filed:
May. 06, 1974
Soichi Nakamura, Kamakura, JA;
Nippon Kogaku K.K., Tokyo, JA;
Abstract
A zoom lens system which is also capable of ultra-closeup photography comprises in succession, as viewed from the object side of the lens system, a focusing lens group of positive power, a variator lens group of negative power, a compensator lens group of positive power and a master lens group of positive power, the variator and compensator lens groups being movable to provide the zooming action. When the lens groups are positioned to provide the minimum zooming focal length configuration of the lens system, the compensator lens groups may be moved toward the master lens group through a distance equal to the maximum amount of its movement during the zooming operation to form a lens system for use in ultra-closeup photography, wherein the focusing, variator and compensator lens groups together form a composite lens group having a focal length equal to or less than the focal length of the master lens group. The focal point of this composite lens group, as viewed from the image side of the lens system, lies on the side of the focusing lens group which faces away from the variator lens group. Alternatively, when the lens groups are positioned to provide the maximum zooming focal length configuration, the variator lens group may be moved toward the focusing lens group through a distance equal to the maximum amount of its movement during zooming operation to form the above-described lens system for ultra-closeup photography.