| 摘要 |
PURPOSE:To attain exact off-set correction by measuring servo off-set quantity in each constant time in case of seek instruction execution, measuring the quantity each time in case of a return-to-zero instruction and updating the quantity. CONSTITUTION:A head moving part 3 moves a head 2 in a direction, where the head 2 crosses the track of a disk 1 having a data track and a servo track. A control part 4 controls the moving part 3 according to a seek instruction from a high order and causes a designated track to access the head 2. In such a case, the control part 4 uses the servo off-set quantity, which is measured by the access of the head 2 to the servo track, as correcting quantity and controls the moving part 3. At such a time, when the seek instruction is received, the servo off-set quantity is measured in each constant time and the quantity is updated. Even in case before the constant time passes, when the return-to-zero instruction is received, the off-set quantity is measured and updated. |
