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. 26, 1993
Filed:
May. 28, 1991
Applicant:
Inventors:
Shuichi Kikuchi, Yokohama, JP;
Masami Itoh, Higashi-Kurume, JP;
Assignee:
Ricoh Company, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G02B / ;
U.S. Cl.
CPC ...
359691 ; 359682 ; 359689 ; 359740 ;
Abstract
In a zoom lens having a high variable magnification, first and second lens groups and respectively having negative and positive focal lengths are sequentially arranged from an object side of the zoom lens to an image side thereof. A combined focal length of an entire lens system is charged by changing a distance between the first and second lens groups while the position of an image surface is constantly held. The zoom lens is constructed such that the second lens group is constructed by front and rear lens groups respectively having positive and negative focal lengths.