Eyepiece

Japanese Patent JP6011163

B2

PROBLEM TO BE SOLVED: To provide an eyepiece lens in which aberration fluctuations due to a diopter adjustment operation are reduced, and aberrations are satisfactorily corrected.SOLUTION: The eyepiece lens comprises: in order from the object side, a negative first lens group G1; a positive second lens group G2; and a negative third lens group G3. In the first lens group G1, the lens surface closest to the eye point side has a concave shape. In the second lens group G2, at lease one lens surface is aspherical, and the curvature of the lens surface closest to the observation object side is larger than the curvature of the lens surface closest to the eye point side. In the third lens group G3, the lens surface closest to the eye point side has a concave shape, and the curvature thereof is larger than the curvature of the lens surface closest to the observation object side. The diopter adjustment operation is performed by moving at least one lens group among the first to third lens groups along the optical axis. The eyepiece lens satisfies the following conditional expression: 0.30