Patent ID: 9651768
Date: 2017-05-16
CPC Classifications: G02B

Claim:
1. An eyepiece lens consisting of, in order from an observed object side: a first spherical lens having a positive refractive power; a second spherical lens having a negative refractive power; and a third lens having a positive refractive power with at least an observed object-side surface thereof having an aspheric shape, wherein the condition expressions below are satisfied: where A3o is a maximum value of an absolute value of a difference between an amount of sag of the aspheric surface and an amount of sag of a spherical surface represented by a paraxial radius of curvature of the aspheric surface at each height up to 6 mm from the center of the observed object-side surface of the third lens, f3 is a focal length of the third lens, f1 is a focal length of the first spherical lens, and f2 is a focal length of the second spherical lens.