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:
Jul. 20, 2021

Filed:

Feb. 27, 2019
Applicant:

Olympus Corporation, Hachioji, JP;

Inventor:

Kengo Osawa, Kamiina, JP;

Assignee:

OLYMPUS CORPORATION, Tokyo, JP;

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G02B 21/02 (2006.01); G02B 13/00 (2006.01);
U.S. Cl.
CPC ...
G02B 21/02 (2013.01); G02B 13/006 (2013.01);
Abstract

An objective includes the first and second groups. The first group includes the first cemented lens with a concave surface facing the object side, the first and second single lenses having positive power, and the second cemented lens with a concave surface facing an image side. The second group includes the third cemented lens with a concave surface facing the object side and a third single lens having positive power. Each of the cemented lenses combines one positive lens with one negative lens. The objective satisfies the following expressions.0.31≤NA<1  (1)2.2≤≤3.3  (2)0<≤1.2  (3) Here, NA is a numerical aperture, f is a focal length at e-line, H is a distance from an object surface to a lens surface closest to an image, a is the sum of air-gap distances in the first group, and b is a thickness of a negative lens in the second cemented lens.


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