Disk drive detecting head touchdown from microactuator signal
AssigneeWestern Digital Technologies, Inc.
InventorYanning Liu
Life of this patent
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Abstract
A disk drive is disclosed comprising a head actuated over a disk surface by a microactuator, and a fly height actuator operable to adjust a fly height of the head. A servo control voltage is applied to the microactuator, and the fly height actuator is adjusted to decrease a fly height of the head. The servo control voltage is filtered to generate a filtered voltage. A touchdown signal is generated in response to the microactuator and the filtered voltage, wherein the touchdown signal indicates when the head contacts the disk.
Claims22
A disk drive comprising:
- a disk comprising first surface and a second surface;
- a first head actuated over the first surface by a first microactuator;
- a second head actuated over the second surface by a second microactuator;
- a fly height actuator operable to adjust a fly height of the first head;
- and
- control circuitry operable to:
- apply a servo control voltage to the first and second microactuators;
- adjust the fly height actuator to decrease a fly height of the first head;
- and
- generate a touchdown signal in response to a difference between a first voltage output by the first microactuator and a second voltage output by the second microactuator, wherein the touchdown signal indicates when the first head contacts the first disk surface.
A disk drive comprising:
- a disk surface;
- a head actuated over the disk surface by a microactuator;
- a fly height actuator operable to adjust a fly height of the head;
- and
- control circuitry operable to:
- apply a servo control voltage to the microactuator;
- adjust the fly height actuator to decrease a fly height of the head;
- filter the servo control voltage to generate a filtered voltage;
- and
- generate a touchdown signal in response to the microactuator and the filtered voltage, wherein the touchdown signal indicates when the head contacts the disk surface.
A method of operating a disk drive comprising a disk comprising first surface and a second surface, a first head actuated over the first surface by a first microactuator, a second head actuated over the second surface by a second microactuator, and a fly height actuator operable to adjust a fly height of the first head, the method comprising:
- applying a servo control voltage to the first and second microactuators;
- adjusting the fly height actuator to decrease a fly height of the first head;
- and
- generating a touchdown signal in response to a difference between a first voltage output by the first microactuator and a second voltage output by the second microactuator, wherein the touchdown signal indicates when the first head contacts the first disk surface.
A method of operating disk drive comprising a disk surface, a head actuated over the disk surface by a microactuator, and a fly height actuator operable to adjust a fly height of the head, the method comprising:
- applying a servo control voltage to the microactuator;
- adjusting the fly height actuator to decrease a fly height of the head;
- filtering the servo control voltage to generate a filtered voltage;
- and
- generating a touchdown signal in response to the microactuator and the filtered voltage, wherein the touchdown signal indicates when the head contacts the disk surface.
Dependencies are inferred from the claim text.