| 摘要 |
PURPOSE:To simplify the structure of a magneto-optical disk device and to reduce its power consumption by providing a circuit which finds the distance between an electromagnet and a magnetism layer from the movement quantity of an objective and controls an exciting current to be supplied to the electromagnet according to the distance. CONSTITUTION:If the surface of a disk 5 slants, the objective 8 moves following up the surface in a focus axial direction to be at a constant distance X. Therefore, a distance Y varies, a distance detector 15 outputs a signal corresponding to the variation, and a distance arithmetic circuit 16 calculates the distance D between the exciting coil 2 and magnetism layer 6 according to the signal. Then the signal D indicating the distance D is inputted to an exciting current control circuit 20, which supplies a control current i1 corresponding to the distance D to the exciting core 2 to drive an electromagnet 1, and a bias magnetic field applied from the electromagnet 1 to the magnetism layer 6 is controlled into the best specific value range. |
