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:
Jan. 22, 1991
Filed:
Jul. 03, 1989
Applicant:
Inventor:
Keiji Moriyama, Yokohama, JP;
Assignee:
Nikon Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G02B / ;
U.S. Cl.
CPC ...
350477 ; 350428 ;
Abstract
A lens system capable of close-up photographing comprises, in succession from the object side, a first lens group having a positive refactive power, a second lens group having a positive refractive power, and a third lens group having a negative refractive power. The first lens group and the second lens group are moved relative from each other for focusing to infinity to a close distance so that the spacing between the first lens group and the second lens group is reduced and the spacing between the second lens group and the third lens group is enlarged. The first and second lens groups are designed to satisfy the following condition: