Abstract: The center of rotation of a disk medium 1 when servo information is written thereto coincides as accurately as possible with its center of rotation in the drive into which the disk medium 1 is assembled. The magnetic disk medium 1 is fixed to a spindle hub 4. A centering pin 8a of a push-aside mechanism 9 pushes aside the magnetic disk medium 1 with respect to the center of the spindle hub 4 until the disk-to-hub gap is moved to one side. Then, with a centering pin 8b of a come-back mechanism 10 placed in the same line intersecting with the center of the spindle, the magnetic disk medium 1 is pushed back to the opposite side.

Abstract: In order to achieve narrow track pitch by measuring, storing and compensating common average values for repeatable runout components between adjacent tracks in a head positioning control system for a magnetic disk drive, there are provided: means for calculating a compensated signal for the average value of the repeatable runout of each servo sector of at least two tracks of servo information reproduced from a magnetic disk, on the basis of an inverse function of the sensitivity characteristics of the tracking control system; means for storing the calculated signal; and means for compensating the servo signal on the basis of this signal.

Abstract: In order to achieve narrow track pitch by measuring, storing and compensating common average values for repeatable runout components between adjacent tracks in a head positioning control system for a magnetic disk drive, a compensation signal is calculated for the average value of the repeatable runout of each servo sector of at least two tracks of servo information reproduced from a magnetic disk, on the basis of an inverse function of the sensitivity characteristics of the tracking control system. The compensation signal is stored, and thereafter used for compensating the servo signal.

Abstract: The center of rotation of a disk medium 1 when servo information is written thereto coincides as accurately as possible with its center of rotation in the drive into which the disk medium 1 is assembled.

Abstract: In order to achieve narrow track pitch by measuring, storing and compensating common average values for repeatable runout components between adjacent tracks in a head positioning control system for a magnetic disk drive, there are provided: means for calculating a compensated signal for the average value of the repeatable runout of each servo sector of at least two tracks of servo information reproduced from a magnetic disk, on the basis of an inverse function of the sensitivity characteristics of the tracking control system; means for storing the calculated signal; and means for compensating the servo signal on the basis of this signal.