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:
Sep. 25, 2018
Filed:
Mar. 06, 2017
Applicant:
Hoya Corporation, Tokyo, JP;
Inventors:
Akitoshi Usui, Tokyo, JP;
Yutaka Takakubo, Saitama, JP;
Assignee:
HOYA CORPORATION, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G02B 13/18 (2006.01); G02B 13/00 (2006.01); G02B 9/60 (2006.01); G02B 9/62 (2006.01); G02B 9/64 (2006.01); G02B 15/177 (2006.01);
U.S. Cl.
CPC ...
G02B 13/006 (2013.01); G02B 9/60 (2013.01); G02B 9/62 (2013.01); G02B 9/64 (2013.01); G02B 13/002 (2013.01); G02B 13/0045 (2013.01); G02B 13/18 (2013.01); G02B 15/177 (2013.01);
Abstract
An imaging optical system includes a positive or negative first lens group including a negative lens element closest to the object, a diaphragm, and a positive second lens group. The negative lens element closest to the object has an object-side aspherical surface including a paraxial convex surface, a paraxial curvature that is the greatest within the effective aperture, and a portion within the effective aperture having a curvature less than ½ of the paraxial curvature. These conditions are satisfied:1/<1.351/>0.4−2.5<1/<−1.3>56