| 摘要 |
PURPOSE:To improve the accuracy of attachment of an objective lens holding body to a base by coupling a pole brace, the objective lens holding body, and a rigid plate with shafts and bearings. CONSTITUTION:When electromagnets 39a and 39b are operated to apply a force in the X direction, namely, the focus control direction to a magnetic body 25, an objective lens holding body 23 tries to move in the X direction, and parts of rigid plates 5 and 7 on sides of an upper-stage second shaft 73 and a lower-stage second shaft 62 are moved in the X direction with an upper- stage first shaft 71 and a lower-stage first shaft 57 as centers. Since the magnetic body 25 stuck to the objective lens holding body 23 is attracted strongly by a permanent magnet 33 at this time, the objective lens holding body 23 keeps the vertical attitude. That is, since central bearings 59 and 69 stuck to the objective lens holding body 23 are rotated around the lower-stage second shaft 62 and the upper-stage second shaft 73 though the upper-stage second shaft 73 and the lower-stage second shaft 62 are moved minutely in the X direction, the vertical attitude of the objective lens holding body 23 is kept.
|
