| 摘要 |
PROBLEM TO BE SOLVED: To provide an ocular optical system which has a simple configuration and yet is suitable for electronic viewfinders.SOLUTION: An ocular optical system comprises, in order from an object side to exit-pupil side, a first lens comprising a positive single lens and having positive power, a second lens comprising a negative single lens and having negative power, and a third lens group having positive power, and satisfies conditional expressions (1) and (2) below: (1) 0.53<L2n×m2a<2, (2) 0.75<f3/f<0.854, where L2n represents a refractive index of the second lens (negative single lens) for the d-ray, m2a represents a surface lateral magnification of an object-side surface of the second lens (negative single lens), f3 represents a focal length of the third lens group, and f represents a focal length of the entire system.SELECTED DRAWING: Figure 1 |
