Data storage device calibrating a laser power for heat assisted magnetic recording based on slope of quality metric
AssigneeWestern Digital Technologies, Inc.
InventorsPoornima Nookala, Phillip Scott Haralson
Life of this patent
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Abstract
A data storage device is disclosed comprising a disk and a head actuated over the disk, wherein the head comprises a laser configured to heat the disk while writing data to the disk. The laser power is adjusted and a pattern is written to a target track at the adjusted laser power. The pattern is read from the target track to generate a read signal, and a quality metric is generated based on the read signal. The process is repeated at least once, and a write power for the laser is configured based on a slope of the quality metric.
Claims26
A data storage device comprising:
- a disk;
- a head actuated over the disk, the head comprising a laser configured to heat the disk while writing data to the disk;
- and
- control circuitry configured to:
- (a) adjust a laser power for the laser;
- (b) write a pattern to a target track at the adjusted laser power;
- (c) read the pattern from the target track to generate a read signal;
- (d) amplify the read signal using a variable gain amplifier
- (e) generate a quality metric based on a setting for the variable gain amplifier;
- (f) repeat blocks (a) through (e) at least once;
- and
- (g) configure a write power for the laser based on a slope of the quality metric.
A data storage device comprising:
- a disk;
- a head actuated over the disk, the head comprising a laser configured to heat the disk while writing data to the disk;
- and
- control circuitry configured to:
- (a) adjust a laser power for the laser;
- (b) write a first pattern to a target track at the adjusted laser power;
- (c) read the first pattern from the target track to generate a first read signal;
- (d) generate a first quality metric based on the first read signal;
- (e) write a second pattern to the target track at the adjusted laser power;
- (f) read the second pattern from the target track to generate a second read signal;
- (g) generate a second quality metric based on the second read signal;
- (h) generate a third quality metric based on the first quality metric and the second quality metric;
- (i) repeat blocks (a) through (h) at least once;
- and
- (j) configure a write power for the laser based on a slope of the third quality metric.
A method of operating a data storage device, the method comprising:
- (a) adjusting a laser power for a laser;
- (b) writing a pattern to a target track on a disk at the adjusted laser power;
- (c) reading the pattern from the target track to generate a read signal;
- (d) amplifying the read signal using a variable gain amplifier;
- (e) generating a quality metric based on a setting for the variable gain amplifier;
- (f) repeating blocks (a) through (e) at least once;
- and
- (g) configuring a write power for the laser based on a slope of the quality metric.
A method of operating a data storage device, the method comprising:
- (a) adjusting a laser power for a laser;
- (b) writing a first pattern to a target track on a disk at the adjusted laser power;
- (c) reading the first pattern from the target track to generate a first read signal;
- (d) generating a first quality metric based on the first read signal;
- (e) writing a second pattern to the target track at the adjusted laser power;
- (f) reading the second pattern from the target track to generate a second read signal;
- (g) generating a second quality metric based on the second read signal;
- (h) generating a third quality metric based on the first quality metric and the second quality metric;
- (i) repeating blocks (a) through (h) at least once;
- and
- (j) configuring a write power for the laser based on a slope of the third quality metric.
Dependencies are inferred from the claim text.