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:
Jul. 07, 2009
Filed:
May. 09, 2007
Hiroshi Yamada, Saitama, JP;
Kimiaki Nakazawa, Saitama, JP;
Hiroshi Yamada, Saitama, JP;
Kimiaki Nakazawa, Saitama, JP;
Fujinon Corporation, Saitama-Shi, JP;
Abstract
A negative first group Gis fixed when a power of the projection zoom lens varies and has a focusing function. A positive second group G, a positive or negative third group G, a positive fourth group Gand a positive or negative group Gmove with a mutual relationship. A sixth group Gfunctions as a relay lens. The fifth group Gincludes a cemented lens formed by cementing a negative meniscus lens Lhaving a convex surface directed to the magnification side, a negative lens Land a positive lens Lin order from a magnification side, and a positive lens Lhaving a convex surface directed to a reduction side. Also, an expression |F|/F>4.5 is satisfied where F denotes a focal length of the projection zoom lens at a wide-angle end and Fdenotes a focal length of the fifth group.