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:
Jan. 30, 2007
Filed:
Nov. 30, 2005
Applicant:
Akira Sawamoto, Suwa, JP;
Inventor:
Akira Sawamoto, Suwa, JP;
Assignee:
Nittoh Kogaku K.K., , JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G02B 15/14 (2006.01);
U.S. Cl.
CPC ...
Abstract
A zoom lens system that includes lens groups Gto Gthat have negative, positive, positive, negative and positive refractive power respectively in the order from a screen side is provided. The fourth lens group Gincludes a cemented lens made up of a negative lens that is concave on the screen side and a convex lens. The zoom lens system satisfies conditions below1.152<2.0504<70 where fw is a combined focal length of the zoom lens system at a wide-angle end, fis a combined focal length of the second lens group, and Δvdis a difference in the respective Abbe numbers vd of lenses composing the cemented lens in the fourth lens group G