| 摘要 |
PURPOSE:To eliminate the influence of sliding frictional force at the time of moving and, at the same time, to prevent a drop in control performance caused by the difference in attitude, by constituting an objective lens holding body, parallel springs, and intermediate supporting body in such a way that they rotate in one body around a rotating axis in the tracking direction. CONSTITUTION:The fixed section 6 of a base is supported by an intermediate supporting body 14 under a rotatable condition around a rotating axis formed by the spatial line of intersection of plate springs 16A and 16B. An objective lens holding body 8 and parallel springs 13A and 13B together with the intermediate supporting body 14 are fitted around an eccentric axis 18 including the rotating axis in one body under a rotatable condition and it is previously arranged that, when the rotating angle is small, an objective lens 2 moves in a direction which is almost equal to the tracking direction 11. Moreover, the plate springs 16A and 16B constituting a cross spring produce restoring force following to the rotation and maintain the neutral position of the tracking direction. If the plate springs 16A and 16B are prepared by using a visco-elastic material, such as plastic, fiber-reinforced plastic, rubber, etc., a damping characteristic which suppresses the amplitude when resonance occurs can be given to the springs 16A and 16B. |
