Disk drive performing spiral scan of disk surface to detect residual data
AssigneeWestern Digital Technologies, Inc.
InventorsYap Han Ng, Charles A. Park, Songwut Jomthaisong, Siri S. Weerasooriya, Brian P. Rigney
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Abstract
A disk drive is disclosed comprising a disk surface comprising a radius, a head operable to generate a read signal, and a voice coil motor (VCM) operable to actuate the head over the disk surface. A back electromotive force (BEMF) voltage generated by the VCM is measured. The VCM is controlled to move the head over substantially the entire radius of the disk surface in response to the BEMF voltage, and while moving the head the read signal from the head is processed to detect residual data recorded on the disk surface after erasing the disk surface.
Claims22
A disk drive comprising:
- a disk surface comprising a radius;
- a head operable to generate a read signal;
- a voice coil motor (VCM) operable to actuate the head over the disk surface;
- and
- control circuitry operable to:
- measure a back electromotive force (BEMF) voltage generated by the VCM;
- control the VCM to move the head over substantially the entire radius of the disk surface in response to the BEMF voltage;
- and
- while moving the head, process the read signal from the head to detect residual data recorded on the disk surface after erasing the disk surface.
A method of operating a disk drive comprising a disk surface comprising a radius, a head operable to generate a read signal, and a voice coil motor (VCM) operable to actuate the head over the disk surface, the method comprising:
- measuring a back electromotive force (BEMF) voltage generated by the VCM;
- controlling the VCM to move the head over substantially the entire radius of the disk surface in response to the BEMF voltage;
- and
- while moving the head, processing the read signal from the head to detect residual data recorded on the disk surface after erasing the disk surface.
Dependencies are inferred from the claim text.