| 摘要 |
PURPOSE:To reduce the displacement amt. of a data head by finding the averaged value of the displacement amt. of the servo head set at a specific servo information position and specific servo information and setting the servo head at the position of the mean value. CONSTITUTION:The magnetic disk 14 having a servo face 14a and a servo head 11 are arranged at respectively 2nd step from a lower step and upper step and a data head 12 is arranged by taking those excepting that as data disks 4. The head 11 is positioned at the specified servo track, the displacement amt. is found by a servo information convertor 19 by amplifying by each amplifier 18 the displacement amt. of each head 11 and each servo track and the mean value is found by a averaging circuit 20. The head 11 is positioned by controlling a driving mean 13 to the position of this mean value by a control circuit 21. The half position in the relative displacement of two heads 11 is thus set zero as the mean value of the whole displacement of the head 12 and the displacement amt. can be reduced more than in the past even if the tendency of the displacement varies.
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