Hard disk drive apparatus and method to determine contact between a head and a disk of a hard disk drive

摘要

FOD (fly on demand) point of contact between the hard disk drive and FOD head and disk that contains the head this method is disclosed for determining the . The head includes a heating coil that can be applied to a variety of power levels . The determination method comprises the step of determining the head position estimation error data . Deviation of the estimated error data , and are generated by the different power values is used to determine the point of contact between the head and the disk . And the determination method may also collect a plurality of amplification gain control signal (SAGC), and calculates the average value of the SAGC . SAGC jimyeo average of values at different power levels are generated , is used to determine the point of contact between the head and the disk .