Contact detection and calibration for electrostatic fly height control in a disc drive
AssigneeSeagate Technology LLC
InventorsJason W. Riddering, Lee C. Knippenberg
Life of this patent
Estimating the term…
Abstract
A disc drive includes a head with an air bearing surface that provides a fly height spacing. A fly height spacing control system provides a control signal to a head electrical connection on a head and a disco electrical connection on a disc. Fly height is controlled electrostatically. A disconnect circuit couples the control signal to the disc electrical connection. The disconnect circuit provides a disconnection of the control signal when contact is sensed. A contact sensor senses an electrical current component of the control signal that indicates contact between the head and the disc.
Claims28
A disc drive, comprising:
- a disc having a disc electrical connection;
- a read/write head having an air bearing surface shaped to provide a fly height spacing between the air bearing surface and the disc, the read/write head having a head electrical connection connected to a conductive region of the read/write head that faces the disc;
- a fly height spacing control system including a controller generating a control signal coupled to the disc electrical connection and the head electrical connection;
- a contact sensor sensing an electrical current component of the control signal indicative of contact between the disc and the read/write head, the contact sensor providing a contact sensor output;
- and
- a disconnect circuit coupling the control signal from the controller to the head electrical connection, the disconnect circuit providing a disconnection of the control signal responsive to the contact sensor output.
A method of reducing damaging contact between a read/write head and a disc in a disc drive, comprising:
- providing a fly height spacing between an air bearing surface on the read/write head and the disc;
- providing a head electrical connection on the read/write head, the head electrical connection connecting to a conductive region of the read/write head that faces the disc;
- providing a disc electrical connection that is connected to the disc;
- providing a control signal from a fly height spacing control system to the head electrical connection and the disc electrical connection;
- sensing an electrical current component of the control signal indicative of contact between the disc and the read/write head, and providing a contact sensor output;
- and
- disconnecting the control signal from the head electrical connection responsive to the contact sensor output.
A disc drive, comprising:
- a disc and a read/write head that has an air bearing surface shaped to provide a fly height spacing between the air bearing surface and the disc, the fly height spacing being controlled by a fly height spacing control system;
- means for sensing contact between the disc and the read/write head and means for disconnecting the fly height spacing control system when contact is sensed.
Dependencies are inferred from the claim text.