SYSTEM AND METHOD FOR CALIBRATING AND CONTROLLING A FLY-HEIGHT ACTUATOR IN A MAGNETIC RECORDING DISK DRIVE

摘要

A system for calibrating and controlling a fly-height actuator of a magnetic recording disk drive and a method therefor are provided to exactly control the fly-height actuator so that intervals between a head and a disk are controlled. When an air-bearing slider(13) is out of contact with a surface of a rotatable disk(10), the amplitude of a read-head signal digitalized over a predetermined frequency range is integrated to determine a reference value. A control signal is applied to a fly-height actuator to reduce intervals between a head(60) and the disk(10). When the intervals are reduced, the amplitude of the digitalized read-head signal is integrated as a measurement value. If the measurement value is larger than the reference value, a fly-height actuator control signal is recorded as an HDC(Head Disk Contact) value. The amplitude of a series of digitalized read-head signals is measured for a series of fly-height control signal values. The head-disk intervals are calculated from the measured amplitude. Alterations of the fly-height actuator control signal values and alterations of the head-disk intervals are correlated together.