| 摘要 |
PURPOSE: To obtain the objective lens driving device having good dynamic characteristics and static characteristics by making an inertial axis of a movable holder equipped with plural objective lenses, a coil fitting part and a yoke inserting hole align a spindle. CONSTITUTION: The movable holder 12 having lens holding parts 12c for mounting one pair of objective lenses 13 and 14 on the upper surface is fitted to the spindle 11 turnably and slidably by a main axis inserting hole 12b. The movable holder 12 is provided with the lens holding parts 12c on the upper surface, a tracking drive coil 15 and a focusing drive coil 16 on the circumferential wall surface and moreover, the yoke inserting hole 12a at a position symmetrical to the spindle inserting hole 12b in its inside. The objective lenses 13 and 14 are made of the same material, in the same shape and mass, and hence the movable holder 12 assembled with these parts is finally balanced. By this structure, the inertial axis of the movable holder 12 is aligned with spindle, thus obtaining good dynamic characteristics and static characteristics. |
