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:
Oct. 30, 2012

Filed:

Oct. 04, 2011
Applicant:

Yuko Katahira, Tokyo, JP;

Inventor:

Yuko Katahira, Tokyo, JP;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G02B 9/60 (2006.01); G02B 9/62 (2006.01);
U.S. Cl.
CPC ...
Abstract

Provided is a simple-structured endoscope objective lens suitable for a compact, high-resolution image acquisition element. Provided is an objective lens constituted of a first negative lens, a second positive lens, an aperture stop, a third positive lens, and a joined lens arranged in that order from an object side, the joined lens being formed of a fourth positive lens and a fifth negative lens and satisfying the expressions (1) and (2), and the objective lens satisfies the expression (3):nn≧2.0  (1)12<(ν)<34  (2)1.52<(23/fl)<1.75  (3)where nn, νp, νn, fand fl denote a refractive index at d-line of the fifth lens, an Abbe number of the fourth lens, an Abbe number of the fifth lens, a combined focal length of the second lens and the third lens, and a focal length of the entire, respectively.


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