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.

Date of Patent:
May. 11, 2010

Filed:

Oct. 07, 2008
Applicant:

Kenji Iijima, Suwa, JP;

Inventor:

Kenji Iijima, Suwa, JP;

Assignee:

Nittoh Kogaku K.K., Nagano, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G02B 15/14 (2006.01);
U.S. Cl.
CPC ...
Abstract

A zoom lens system consists, in order from an object side to an image-forming side, of a first negative lens group G, a second positive lens group G, and a third positive lens group G. The first lens group Gconsists of one negative lens and one positive lens, the second lens group Gconsists of a cemented lens composed of a positive lens and a negative lens, and one meniscus lens that is concave on the image-forming side, the third lens group Gconsists of a single positive lens, and a combined focal length fof the second lens group, a focal length Lfof the meniscus lens of the second lens group, a combined focal length fw of the zoom lens system at a wide angle end, a combined focal length fof the third lens group, a radius of curvature Ro of an object side surface of the positive lens in the cemented lens, and a radius of curvature Ri of an image-forming side surface of the positive lens in the cemented lens satisfy the following conditions0<|2/23|<0.3−2.0<<−1.00.25<3<0.45.


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