| 摘要 |
PURPOSE:To reduce the weight of a movable part and to increase acceleration by arranging a bearing part of a rotary shaft which is formed as a movable part united with an objective lens barrel on the fixed part side. CONSTITUTION:The movable part is constituted of the objective lens barrel 1 and the rotary shaft 14 and the bearing part 15a is constituted so as to be used also for a york part 15. The york part 15 is constituted of members 15a-15c. The minimum thickness of the member 15a in its radius direction is set up under the consideration of mechanical strength or resonation and the length of the sliding surface between the shaft 14 and the bearing part 15a in the axial direction is expanded under the consideration of the inclination of the incident light axis of an objective lens. |
