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. 18, 1994
Filed:
Nov. 29, 1991
Applicant:
Inventor:
Takayuki Ito, Tokyo, JP;
Assignee:
Asahi Kogaku Kogyo K.K., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G02B / ; G02B / ;
U.S. Cl.
CPC ...
359676 ; 359691 ; 359692 ; 359740 ;
Abstract
A zoom lens system includes, in order from the object side, the first lens group having a positive focal length and the second lens group having a negative focal length. The system performs zooming by changing the distance between the first and second lens groups. The first lens group has a negative lens element on the side closest to the object that has a concave surface of large curvature directed towards the image plane and the first lens group satisfies the specific conditions.