| 摘要 |
PURPOSE:To improve the accuracy of positioning of a magnetic head, by arranging a magnet magnetized to the direction of center axis of a torsional coil spring providing the initial torque for a magnetic head arm, thus preventing a surging phenomenon of a coil spring. CONSTITUTION:In operating a step motor 16 and seeking a magnetic head 11 in a high speed to an objective position on a magnetic head, since a torsional coil spring 17 is moved in a magnetic field of a magnet 20, an electromotive force is produced across the spring 17. Since this electromotive force causes a current to flow through a short-circuit wire across the spring 17, the movement of the spring 17 is suppressed, allowing to damp the entire movement. Thus, the surging phenomenon of the spring 17 can be prevented or attenuated in a short time. |
