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:
Mar. 31, 1992
Filed:
Nov. 28, 1990
Satoshi Iwasaki, Toyokawa, JP;
Minolta Camera Kabushiki Kaisha, Osaka, JP;
Abstract
A zoom lens system comprising, in order from an enlargement side, a first lens unit of a positive power, a second lens unit of a positive power, a third lens unit of a negative power, and a fourth lens unit of a positive power. During a magnification varying operation from a longest focal length condition to a shortest focal length condition, the first lens unit, the third lens unit and the fourth lens unit are movable simply from the enlargement side to a reduction side. The second lens unit is closest to the third lens unit in the longest focal length condition, and closest to the first lens unit in the shortest focal length condition. This zoom lens system satisfies the following conditions: