Patent ID: 9551864
Date: 2017-01-24
CPC Classifications: G02B,G03B

Claim:
1. An eyepiece lens comprising in order from an object side to an observation side: a first lens having a positive refractive power; a second lens having a negative refractive power; and a third lens having a positive refractive power, wherein a lens surface of the first lens on the object side has a convex shape, wherein a lens surface of the second lens on the observation side has a concave shape, and wherein the following conditional expressions are satisfied: where f represents a focal length of the eyepiece lens, f 11 represents a focal length of the lens surface of the first lens on the object side, f 22 represents a focal length of the lens surface of the second lens on the observation side, r 1 a represents a curvature radius of the lens surface of the first lens on the object side, and r 2 b represents a curvature radius of the lens surface of the second lens on the observation side.