Patent ID: 6034829
Filing Date: 2000-03-07
Classification: G11B

Abstract:
A disk drive which has a magneto-resistance (MR) element as a read element and where servo areas, which include position data, and data areas are separated and recorded on a disk and each of said servo areas has a servo pad area at the start position of the servo area, also has an erase area which is a no-signal portion, immediately after and adjoining said servo pad area, and further has a Gray code area where track position data of the disk has been recorded, immediately after and adjoining said erase area, said disk drive comprising:a combination of the disk in which a servo signal pattern has been formed and the MR element where the direction of the bias magnetization thereof has been set, in such a manner that a polarity of a start bit recorded signal of a start position of said Gray code area, which is detected by said MR element, is a polarity opposite to a polarity indicated by a resistance increase of said MR element due to a thermal asperity; andmeans for executing a reading of a signal by a method of alternately reading out signals different in polarity.