Patent ID: 6545832
Filing Date: 2003-04-08
Classification: G11B

Abstract:
A disk drive in which a signal recorded on a disk is read using heads, and in which when an error is detected in the read signal, a retry operation is carried out for rereading the same signal recorded on the disk, said disk drive comprising:an error detection unit for detecting an error value in the signal read using the heads; a memory in which a set value of a parameter concerning a relative position of the heads with respect to the disk attained at the time of reading the signal and/or a set value of a parameter concerning a circuit for processing a signal read using the heads is stored; and a control unit that when judging from the error value detected in the signal read using the heads that a first retry operation is needed, (a) changes the parameter value by a predetermined value, (b) instructs rereading of the same signal, (c) calculates a first new parameter value according to a change value &bgr; by which the parameter value is changed and a magnitude of a change in an error value detected between the read and a reread signal, and (d) updates the parameter value stored in said memory using the first new parameter value, and the control unit repeats steps (a)-(d) until an error is eliminated or the error value falls below a predefined value or until the number of rereadings (retries) reaches a predetermined number.