| 摘要 |
<p>A voice coil type actuator wherein the length in an axial direction and the number of parts is reduced without deteriorating a required function and the magnetic flux density in a space in which a movable coil (11) is located is substantially uniform over the entire length in an axial direction. The voice coil type actuator comprises a fixed guide shaft (14) having a radial portion made of a permeable material and a movable body supported for axial sliding movement on the guide shaft. The movable coil (11) is supported coaxially with the guide shaft (14) on the movable body (13). A yoke (17) having a substantially cylindrical profile is disposed in such a manner as to surround a range of movement of the movable coil (11), and a pair of fixed magnets (18,18') are disposed in contact with the guide shaft (14) and the yoke (17) and magnetized with the opposite polarities in a radial direction. The yoke (17) has a recess (17a) formed therein in the axial direction of the yoke, and a movable member to be moved by the actuator is supported at a portion of the movable body (13) which extends laterally through the recess in the yoke. <IMAGE></p> |
