| 摘要 |
<p>A drive source has a base member for installation in a housing whose inside can be a vacuum atmosphere. A partitioning wall for partitioning between an air atmosphere and a vacuum atmosphere is provided on the base member, and a pivot member as the pivot section of the drive source is provided at a place different from that of a pivot member on the base member. An armature, a production source of dust, is provided on the air atmosphere side of the partition wall, so that the vacuum atmosphere side can be maintained at high cleanliness. Further, since the partition wall and the pivot members are arranged at different places, there is no need to consider partition wall rigidity which supports the pivot member, and as a result, the partition wall can be thinned. In addition, affection caused by vibration and inertia by pivoting of the pivot member can be reduced, so that the distance from the armature to a magnet provided on the pivot member is less than that in a conventional one. As a result, high accuracy of a stop position can be achieved.</p> |
