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:
Apr. 02, 1996
Filed:
Sep. 14, 1993
Applicant:
Inventor:
Nobutaka Minefuji, Hokkaido, JP;
Assignee:
Asahi Kogaku Kogyo Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G02B / ;
U.S. Cl.
CPC ...
359687 ; 359676 ; 359686 ;
Abstract
A variable power projection lens is provided and includes, in order from an magnifying side (a screen side), a first lens group having positive power, a second lens group having negative power, a third lens group having positive power, and a fourth lens group having positive power. At least two lens groups of the first, second, and third lens groups are movable along the optical-axis direction to vary the image magnification and to focus, and the variable power projection lens satisfies the following condition: