| 摘要 |
PURPOSE:To decrease the number of parts and to reduce the weight of a movable part of an optical head by using a magnetic circuit of an optical head feeding linear motor also to a tracking drive magnetic circuit and a focusing derive magnetic circuit. CONSTITUTION:When a current flows to a convertible coil 16 set in a bias magnetic field of a magnetic circuit 9, the force of the disk radius direction is produced to drive a main body base 2 along a guide shaft 3. Thus the coil 16 functions to feed an optical head 1 and drives a focusing action. When a control current flows to a focusing coil 8, the up-down force is produced since a lower winding part is set into the bias magnetic field of the circuit 9 to perform the focusing drive. Thus it is not needed to provide both focusing and tracking driving magnetic circuits to the head 1 and therefore the structure of the head 1 is simplified.
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