| 摘要 |
PURPOSE:To always give a magnetic field in constant intensity to a vertically magnetizing film by feeding a displacement amt. of an objective lens obtained from a capacitance type displacement measuring electrode back to an actuator of a magnetic field generating part and controlling the relative position between an optical head and the magnetic field generating part accordingly. CONSTITUTION:A displacement amt. of the objective lens 6 corresponding to a displacement amts. of a magneto-optical disk 1 in its focusing direction and tracking direction respectively is detected by the capacitance type displacement measuring electrodes 14 and 14'. Then, by feeding this back to an external magnetic field generating part 4 provided with the actuators 12 and 12' which are movable in the focusing direction and the tracking direction, a beam spot converged on the vertically magnetizing film 7 and a magnetic field generating surface 16 are controlled in their relative positional relationship. By this method, even when the magneto-optical disk is wobbly in surface and track, the magnetic field in constant intensity can always be supplied in the vicinity of the beam spot converged on the vertically magnetizing film 7. |
