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:
May. 07, 2002
Filed:
Sep. 07, 2000
Applicant:
Inventors:
Masayuki Murata, Saitama, JP;
Takayuki Ito, Saitama, JP;
Assignee:
Asahi Kogaku Kogyo Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G03B 1/700 ;
U.S. Cl.
CPC ...
G03B 1/700 ;
Abstract
A macro zoom lens system includes at least three lens groups, such as, a positive first lens group, a negative second lens group, and a positive third lens group, in this order from the object. Upon zooming, at least two lens groups are made moveable. On the other hand, upon focusing at any focal length in the focal-length range defined by the short focal length extremity and the long focal length extremity, any one of the lens groups other than the first lens group is made moveable. Furthermore, at the shortest object-to-image distance, an image magnification of more than ½ is obtained at the long focal length extremity.