| 摘要 |
PURPOSE:To reduce the access time by writing the 1st and 2nd reference information into areas shifted to each other in the drive direction of a disk as servo information, and detecting an off-track value from a read signal so as to apply off-track correction. CONSTITUTION:The 1st reference information 10 and the 2nd reference information 20 are written in areas shifted to each other in the drive direction of a disk 1 as servo information. The off-track is detected from the read signal of the information 10, 20 by an off-track detection circuit 40 and at every time the value exceeds the allowable value, a control command is given from an off-track correction circuit to a head position operation circuit 30 to correct the off-track. When the off-track value is within a permissible value and a control command is given to the circuit 30 based on the information 20, a control end confirming circuit outputs an end signal representing the end of positioning control of the head 3. Then the head is surely positioned to a normal position on a prescribed track within one drive period of the disk 1.
|
