| 摘要 |
PURPOSE:To reduce a magnetic flux leaked to a disk by arranging a tracking permanent magnet in the center of a closed magnetic path and swaying a tracking drive coil in a direction perpendicular to the recording face of a disk in a magnetic clearance at the time of driving the coil in a focus direction. CONSTITUTION:A tracking magnetic circuit 18 is composed of a tracking yoke 17, a rectangular permanent magnet 15 surely adhering to the center of the inner bottom wall 17a of the tracking yoke 17 and a tracking yoke 16 surely adhering to said magnet 15. A tracking drive coil 21 moves in the radius direction of the optical magnetic disk 6 in the tracking magnetic clearance 20 and in the direction vertical to the recording surface of the optical magnetic disk 6 at the time of focus drive. The tracking magnetic circuit 18 forms a closed magnetic path, and the tracking permanent magnet 15 is positioned in the center of said closed magnetic path. Thus the influence of the leaked magnetic flux to a disk recording medium can be reduced. |
