Disk drive that discerns the polarity of a head signal from a sync mark to enhance data detection
AssigneeWestern Digital Technologies, Inc.
InventorsGrant S. Christiansen, Mark D. Hagen
Life of this patent
Estimating the term…
Abstract
The present invention may be regarded as a disk drive comprising a disk having a plurality of data tracks, each data track comprising a plurality of sectors. A sync mark detector detects a sync mark pattern in a sector, wherein when the sync mark pattern is detected a sync mark detect signal and a polarity signal are generated. The polarity signal represents an expected polarity of pulses in a read signal representing data stored in the sector, wherein the polarity signal enhances the detection of an estimated data sequence from the read signal.
Claims12
A disk drive comprising:
- (a) a disk comprising a plurality of data tracks, each data track comprising a plurality of sectors, each sector comprising:
- a preamble field for storing a predetermined periodic data sequence;
- a sync field for storing a predetermined sync mark pattern;
- and
- a data field for storing data;
- (b) a head actuated radially over the disk for generating a read signal comprising a plurality of polarity alternating pulses;
- (c) a sync mark detector for detecting the sync mark pattern in the read signal, wherein when the sync mark pattern is detected the sync mark detector generates a sync mark detect signal and a polarity signal, the polarity signal indicative of an expected polarity of the pulses in the read signal representing the data stored in the data field;
- (d) a data detector for detecting an estimated data sequence from the read signal using the polarity signal to enhance performance;
- and
- (e) a data decoder, responsive to the sync mark detect signal, for decoding the estimated data sequence into a decoded data sequence.
A method of detecting data stored in a disk drive, the disk drive comprising a disk comprising a plurality of data tracks, each data track comprising a plurality of sectors, each sector comprising a preamble field for storing a predetermined periodic data sequence, a sync field for storing a predetermined sync mark pattern, and a data field for storing the data, the method comprising the steps of:
- (a) actuating a head radially over the disk to generate a read signal comprising a plurality of polarity alternating pulses;
- (b) detecting the sync mark pattern in the read signal;
- (c) when the sync mark pattern is detected, generating a sync mark detect signal and a polarity signal, the polarity signal indicative of an expected polarity of the pulses in the read signal representing the data stored in the data field;
- (d) detecting an estimated data sequence from the read signal using the polarity signal to enhance performance;
- and
- (e) decoding the estimated data sequence into a decoded data sequence in response to the sync mark detect signal.
Dependencies are inferred from the claim text.