MAGNETIC DISK DEVICE FOR DECREASING OCCURRENCE PROBABILITY OF READING ERROR BY SCRATCH ON SURFACE OF MAGNETIC DISK

摘要

PURPOSE: A magnetic disk device for decreasing occurrence probability of reading error by scratch on surface of magnetic disk is provided to accurately read data by opening a reading gate after a certain time for indicating a difference of an open time and a delay time is lapsed. CONSTITUTION: A servo signal processing unit(13) sets a reading timing based on an output of a synchronous unit(13), reads an SAM(2) for recognizing an address, and detecting an output level of an A burst signal(3a) and a B burst signal(3b). A control unit(10) computes a difference between an output level of the burst signal(3a) and an output level of the burst signal(3b). A VCM(15) performs a track revise for moving a head(16) to a track center of a disk. The control unit(10) performs a process for opening a reading gate(12) in a certain time.