Head spacing verification in magnetic disk drive systems during end-user operation
AssigneeHitachi Global Storage Technologies Netherlands B.V.
InventorsPeter M. Baumgart, Erhard T. Schreck
Life of this patent
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Abstract
Magnetic disk drive systems and associated methods are described for verifying a spacing between read/write heads on a slider and a magnetic recording disk during end-user operation. An operating power applied to heating elements in the slider controls the spacing due to thermal protrusion. While in end-user operation, the operating power is temporarily increased to a test power to decrease the spacing. The test power is then evaluated to determine if contact between the read/write heads and the magnetic recording disk is detected. If contact is not detected, then the spacing due to the operating power is determined to be adequate. If contact is detected, then the operating power is recalibrated.
Claims21
A method of verifying a spacing between read/write heads on a slider and a magnetic recording disk within a magnetic disk drive system in end-user operation, wherein an operating power that is determined during calibration of the magnetic disk drive system is applied to heating elements in the slider to control the spacing between the read/write heads and the magnetic recording disk, the method comprising:
- temporarily increasing the operating power to a test power while in end-user operation to reduce the spacing between the read/write heads and the magnetic recording disk;
- determining if the test power causes contact between the read/write heads and the magnetic recording disk;
- and
- if contact is not detected, then determining that the spacing due to the operating power is adequate.
A control system adapted to verify a spacing between read/write heads on a slider and a magnetic recording disk within a magnetic disk drive system in end-user operation, wherein an operating power that is determined during calibration of the magnetic disk drive system is applied to heating elements in the slider to control the spacing between the read/write heads and the magnetic recording disk, the control system comprising:
- a thermal fly height controller adapted to temporarily increase the operating power to a test power while in end-user operation;
- a contact detection system adapted to determine if the test power causes contact between the read/write heads and the magnetic disk;
- and
- a calibration controller adapted to determine that the spacing due to the operating power is adequate if contact is not detected by the contact detection system.
A magnetic disk drive system comprising:
- a magnetic recording disk;
- a slider including read/write heads and heating elements proximate to the read/write heads;
- a control system adapted to apply an operating power that is determined during calibration of the magnetic disk drive system to the heating elements in the slider to control a spacing between the read/write heads and the magnetic recording disk;
- the control system further adapted to:
- temporarily increase the operating power to a test power while in end-user operation to reduce the spacing between the read/write heads and the magnetic recording disk;
- determine if the test power causes contact between the read/write heads and the magnetic recording disk;
- and
- determine that the spacing due to the operating power is adequate if contact is not detected.
Dependencies are inferred from the claim text.