| 摘要 |
PROBLEM TO BE SOLVED: To provide an ocular optical system which is well corrected for various aberrations, particularly for coma aberration and distortion aberration.SOLUTION: An ocular optical system EL includes, in order from an observation-object Ob side, a first lens L1 having positive refractive power, a second lens L2 having negative refractive power and a concave surface on the observation-object Ob side, and a third lens L3 having positive refractive power and a convex surface on an eye-point EP side. During diopter scale adjustment, the third lens L3 is stationary along the optical axis with respect to the observation object Ob, and satisfies the following conditional expressions (1) and (2). 0.65<R31/fe<1.30...(1), and -0.80<(R32+R31)/(R32-R31)<-0.10...(2), where fe represents a focal length of an ocular optical system EL, R31 represents a curvature radius of an observation-object Ob side surface of the third lens L3, and R32 represents a curvature radius of the eye-point EP side surface of the third lens L3. |
