| 摘要 |
PURPOSE:To improve the reliability to temperature variation and reduce the off- track margin of a disk as compared with a conventional device by providing a correcting means which corrects a head positioning mechanism according to temperature variation. CONSTITUTION:A servo head 6 is positioned at a constant position, so the maximum off-track quantity of a data head 7 at this time is Xa, but a data head 4 coupled with an actuator 8 has an offset -Xa/2 and the off-track quantity is Xa-Xa/2=Xa/2 because the servo head is given an offset -Xa/2 with an offset voltage impressed from a temperature compensating circuit 17. Similarly, the off-track quantity is suppressed in low-temperature operation to Xb-Xb/2= Xb/2. The total off-track quantity in high-temperature and low-temperature operation is ¦Xa/2-Xb/2¦, which is reduced to a half as large as usual. The output offset voltage of the temperature compensating circuit 17 is set equally corresponding to the temperature in a main body case 1, but the offset voltage may be adjusted finely for every data head 7 synchronously with a head switching signal. |
