| 摘要 |
PURPOSE:To adjust the position drift of a head to a minimal one by adjusting the head position drift with respect to two adjusting tracks installed at an interval corresponding to the rotational frequency of a screw with the aid of a screw rotating angle. CONSTITUTION:A ball 12 of extension part 11 of a carriage 7 is engaged with a groove 10 of the screw 9 driven by a stepping motor 8, and the rotation of the screw 9 moves the head 5. On the other hand, an adjusting screw 21 is provided with the 1st and 2nd adjusting tracks 22 and 23 having intervals corresponding to the rotational frequency of the screw 9. With this constitution an adjusting disk 2 is mounted instead of the disk 1 to read burst signals A1 and B1 by the head 5. Then the screw 19 is loosened so that the burst signals A1 and B1 can be substantially equal to turn a fitting plate 18, and a screw rotating angle is adjusted. The track 23 is handled in the same manner. Thus the head position drift with respect to tracks except the adjusting one can be suppressed by minimal amount. |
