| 摘要 |
PURPOSE:To measure with a high accuracy an off-track quantity and an eccentric quantity in the radial direction of a track of a disk device by using a magnetic disk in which at least two or more burst-like data blocks are recorded alternately in the inside circumferential and the outside circumferential directions of a disk by making a prescribed track center as a boundary. CONSTITUTION:A sign mark detecting circuit 6 reacts to only a sign mark Ix recorded centering around a prescribed track center N in order to become a reference position of one track, and generates a pulse signal. Also, a data block detecting circuit 7 reacts to all signals recorded on a track containing the sign mark Ix and generates a pulse signal. Accordingly, a microcomputer 8 detects a sign mark detecting signal (c), and thereafter, inputs a digital value converted after passing through a suitable delay time, to an A/D converter 5, whenever a data block detecting signal (d) is detected, by which reproducing output levels of the inside circumferential side block and the outside circumferential side block are obtained alternately by the digital value. |
