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:
Feb. 13, 2018
Filed:
Dec. 22, 2016
Applicants:
Optical Logic Inc., Nagano, JP;
Kantatsu Co., Ltd., Tochigi, JP;
Inventors:
Yoji Kubota, Nagano, JP;
Kenichi Kubota, Nagano, JP;
Hitoshi Hirano, Nagano, JP;
Tomohiro Yonezawa, Tochigi, JP;
Assignees:
OPTICAL LOGIC INC., Nagano, JP;
KANTATSU CO., LTD., Tochigi, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G02B 9/34 (2006.01); G02B 13/00 (2006.01); G02B 27/00 (2006.01); G02B 1/11 (2015.01);
U.S. Cl.
CPC ...
G02B 13/004 (2013.01); G02B 9/34 (2013.01); G02B 27/0025 (2013.01); G02B 1/11 (2013.01);
Abstract
An imaging lens includes a first lens having negative refractive power; a second lens having positive refractive power; a third lens having positive refractive power; and a fourth lens, arranged in this order from an object side to an image plane side. The second lens is arranged to face the third lens. The first lens has a focal length f1 and the fourth lens has an Abbe's number νd4 so that the specific conditional expressions are satisfied.