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:
Dec. 17, 1991
Filed:
Dec. 20, 1990
Toshihiko Ueda, Toyokawa, JP;
Minolta Camera Kabushiki Kaisha, Osaka, JP;
Abstract
A zoom lens system having a negative lens group which includes a negative lens having a concave surface facing the reducing side and a positive lens having a convex surface facing the enlarging side, and a positive lens group which includes a positive lens unit of at least one positive lens having a convex surface facing the enlarging side, a first lens having a concave surface facing the reducing side, a double convex lens, and a second lens having a concave surface facing the enlarging side, and wherein said zoom lens system is standardized by the conditional expression so that the pupil position on the reducing side approaches the image point on the reducing side.