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. 27, 1997
Filed:
Sep. 15, 1995
Applicant:
Inventors:
Hideki Nagata, Sakai, JP;
Soh Ohzawa, Toyonaka, JP;
Hiroyuki Matsumoto, Wakayama, JP;
Masakuni Tai, Machida, JP;
Assignee:
Minolta Camera Co., Ltd., Osaka, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G02B / ;
U.S. Cl.
CPC ...
359686 ;
Abstract
A zoom lens system of the invention is double telephoto type zoom lens system having a positive/negative/positive/negative refractive power arrangement. During zooming from the wide angle side toward the telephoto side, the first through fourth lens units move such that the distance between the first and second lens units increases and the distance between the third and fourth lens units decreases. The refractive power of the first lens unit and the refractive power of the fourth lens unit are appropriately prescribed so that an adequate back focal lens distance is preserved.