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. 11, 1994
Filed:
Jul. 02, 1992
Applicant:
Inventors:
Assignee:
Asahi Kogaku Kogyo K.K., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G02B / ;
U.S. Cl.
CPC ...
359692 ;
Abstract
A zoom lens system for a compact camera, having a zoom ratio of approximately 2 or 3 and a smaller overall lens length at the telephoto end than the focal distance at the telephoto end, and which optically experiences only a small focus shift due to environmental changes such as temperature or humidity. The zoom lens system includes a positive lens group and a negative lens group. A positive plastic lens element is disposed in either the positive lens group or the negative lens group. The magnification of the system is adjusted by varying the distance between the positive and negative lens groups. The zoom lens system satisfies the following conditions: