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. 23, 1993
Filed:
Feb. 12, 1992
Applicant:
Inventor:
Jun Hirakawa, Tokyo, JP;
Assignee:
Asahi Kogaku Kogyo Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G02B / ;
U.S. Cl.
CPC ...
359686 ; 359683 ;
Abstract
A zoom lens comprises at least four lens groups, including a negative first lens group, positive second lens group, negative third lens group and a positive fourth lens group. When the power is varied from wide angle to telescopic, the lens groups are moved such that the distances between the first and second lens groups and between the third and fourth lens groups are reduced. The distance between the second and third lens groups is increased, and an aperture disposed near the second lens group is moved together with the second lens group.