| 摘要 |
The apparatus includes a supporting member disposed at an outer circumference of the ocular optical system and an eyepiece cup. A first member thereof includes a cam follower and a second member thereof includes a cam groove to move the eyepiece cup in an optical axis direction with rotation of the eyepiece cup and an introducing groove through which the cam follower is introduced to the cam groove. One member of the first and second members includes an engaging portion, and another member thereof includes a stopper engaging with the engaging portion to prevent rotation of the eyepiece cup in a direction in which the cam follower is returned from the cam groove toward the introducing groove. The stopper formed integrally with another member is elastically movable so as to be located at and retreated from an engaging position to be engageable with the engaging portion. |
