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:
Nov. 01, 2022
Filed:
Sep. 07, 2018
Hoya Corporation, Tokyo, JP;
Hiroaki Fujii, Tokyo, JP;
Sachiko Nasu, Tokyo, JP;
HOYA CORPORATION, Tokyo, JP;
Abstract
The objective lens unit includes, a front lens group having a negative refractive power, a diaphragm, and a rear lens group having a positive refractive power, in order from an object side. The front lens group includes a negative lens having a concave surface facing an image surface side, and a positive lens having a convex surface facing the object side, and the rear lens group includes a positive lens having a convex surface facing the image surface side and a cemented lens in which a positive lens and a negative lens are cemented. The endoscope objective lens unit satisfies −1.6<f/f<−1.2 and −1.3<f/f<−0.7. Note that fand fare focal lengths of the entire system of the front lens group and the rear lens group, and fis a focal length of a positive lens, in the rear lens group.