Patent ID: 8593749

Claim:
A hard-disk drive, comprising: a head-slider configured to fly in proximity with a recording surface of a magnetic-recording disk, said head-slider comprising: a write element configured to write data to said magnetic-recording disk, a fly-height-adjustment heating element configured to displace said write element towards said magnetic-recording disk, and a position-adjustment heating element configured to displace said write element in at least a direction perpendicular to a flying direction; a fly-height variation compensator configured to generate a signal for compensating variation in fly height of said write element, and configured to add said signal to a control signal for output to said fly-height-adjustment heating element, wherein said fly-height variation compensator is configured to generate a signal for compensating said variation in fly height based on said control signal for output to said position-adjustment heating element; a fly-height variation detector configured to detect said variation in fly height, and configured to output a detection signal; and a second fly-height variation compensator configured to generate a second signal for compensating said variation in fly height based on said detection signal, and configured to add said second signal to said control signal for output to said fly-height-adjustment heating element.