| 摘要 |
PURPOSE:To eliminate a read error impossible for recovery due to the effect of magnetic failure by providing a converting circuit being inputted with a magnetic head position change signal and converting this signal into a corresponding prescribed slice level change command signal to change the slice level by the output of the circuit. CONSTITUTION:When a controller 8 detects an READ error by a CRC function, a signal POS.IN is outputted. A converting circuit 9 converts its output into the slice level change command signal LOW, thereby changing the slice level of a comparator 7 into -VthL. When the effect by a magnetic failure does not reach a normal level -VthN as shown in Fig. C', the READ error is avoided by changing the said level at retrial. When the said effect exceeds a level +VthN as shown in Fig. B', the READ error occurs again. Then, the controller 8 outputs a signal POS.OUT and the converting circuit 9 converts its output into a change command signal HIGH, causing the comparator 7 to change the slice level into +VthH. Thus, no pulse mis-production occurs in the pulser output (e). |
