Method and apparatus for providing a linear position error sensing (PES) signal
First Claim
1. A servo control system for a direct access storage device (DASD) that positions a head of the DASD relative to multiple tracks of a storage medium for executing data access operations on the storage medium the system comprising:
- a servo signal filter that receives a readback signal from the head and produces filtered servo signal data samples;
a servo demodulator that receives the filtered readback servo signal from the servo signal filter and produces a position error signal that indicates the head position relative to a track using a demodulation scheme selected in accordance with a track width profile of the DASD; and
a servo controller that determines the demodulation scheme to be used by the servo demodulator and that processes the position error signal to maintain the head centered relative to the track.
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Accused Products
Abstract
In accordance with the present invention a storage device servo control system that positions a head relative to multiple tracks of a storage medium includes a servo signal filter that receives a readback signal from the head and produces filtered servo signal data samples, a servo demodulator that receives the filtered readback servo signal from the servo signal filter and produces a position error signal that indicates the head position relative to a track using a demodulation scheme selected in accordance with a track width profile of the storage device, and includes a servo controller that determines the demodulation scheme to be used by the servo demodulator and that processes the position error signal to maintain the head centered relative to the track.
23 Citations
25 Claims
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1. A servo control system for a direct access storage device (DASD) that positions a head of the DASD relative to multiple tracks of a storage medium for executing data access operations on the storage medium the system comprising:
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a servo signal filter that receives a readback signal from the head and produces filtered servo signal data samples; a servo demodulator that receives the filtered readback servo signal from the servo signal filter and produces a position error signal that indicates the head position relative to a track using a demodulation scheme selected in accordance with a track width profile of the DASD; and a servo controller that determines the demodulation scheme to be used by the servo demodulator and that processes the position error signal to maintain the head centered relative to the track. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A servo control system that positions a head relative to a storage media with at least one recording surface on which is recorded a servo pattern in a plurality of tracks the head generating a head readback signal from transducing the servo pattern, the servo control system comprising:
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a servo signal filter that receives a readback signal from the head and produces filtered servo signal data samples; a servo demodulator that receives the filtered readback signal from the servo signal filter and produces a position error signal that indicates the head position relative to a track using a demodulation scheme selected in to accordance with a track width profile of the head; a servo assembly that is activated to position the head relative to the storage recording surface; and a servo controller that determines the demodulation scheme to be used by the servo demodulator and that controls the servo assembly in accordance with the position error signal to maintain the head centered relative to the track. - View Dependent Claims (8, 9, 10, 11, 12)
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13. A disk drive having:
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a magnetic storage media on which is recorded a servo pattern comprising a repeating sequence of magnetic transitions extending across the width of tracks; a head assembly having at least one read head for reading the servo pattern recorded in the multiple tracks and generating therefrom a head readback signal; a servo demodulator that receives the filtered readback signal from the head assembly and produces a position error signal that indicates the head position relative to a track using a demodulation scheme selected in accordance with a track width profile of the head; a servo assembly that is activated to position the head relative to the magnetic storage media; and a servo controller that determines the demodulation scheme to be used by the servo demodulator and that controls the servo assembly in accordance with the position error signal to maintain the head centered relative to the track. - View Dependent Claims (14, 15, 16, 17, 18)
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19. A method of producing a data storage system having a storage media with at least one recording surface on which is recorded a servo pattern in a plurality of tracks, at least one head for transducing the servo pattern and generating a head readback signal, and a demodulator that produces a position error sensing signal from the head readback signal to position the head relative to the tracks, the method comprising the steps of:
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recording the servo pattern on each recording surface of the storage media; obtaining a track width profile associated with each recording surface; storing a plurality of demodulation schemes in memory of the data storage system; and selecting a demodulation scheme in accordance with each track width profile to provide a substantially linear position error sensing signal. - View Dependent Claims (20, 21, 22, 23)
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24. A method of controlling the position of at least one transducing head relative to tracks of a storage media comprising a plurality of storage surfaces, the method comprising the steps of:
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determining a storage surface to be accessed with the transducing head for execution of a data operation; selecting a demodulation scheme in accordance with a track width profile for the storage surface; and maintaining the position of the transducing head relative to a track on the storage surface. - View Dependent Claims (25)
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Specification