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US 9,330,688 B1Granted
Procedure that achieves a target areal density for a heat-assisted recording medium
AssigneeSeagate Technology LLC
InventorsWenzhong Zhu, Kaizhong Gao, Michael A. Cordle
Life of this patent
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Abstract
A recording head writes data to a recording medium for one or more iterations. Each iteration involves adjusting a linear data density, a track pitch, and a laser power. From the iterations, a selected linear data density, a selected track pitch, and a selected laser power are determined that together achieve a target areal density and are used to write user data to the recording medium during operation of a hard disk drive.
Claims19
A method comprising:
- determining an initial value of laser power based on incrementing the laser power while recording a signal to a heat-assisted recording medium, the initial value based on a power level that results in saturation when reading back the signal;
- recording data to the heat-assisted recording medium for two or more iterations, each iteration involving the adjustment of, in any order, linear data density, track pitch, and the laser power when writing data to a single track of the recording medium to achieve a target bit error rate for each iteration;
- determining, from the iterations, a selected linear data density, a selected track pitch, and a selected laser power that together achieve a target areal density;
- and
- using the selected linear data density, the selected track pitch, and the selected laser power to write user data to the recording medium.
2 more elements
A method comprising:
- incrementing a laser power applied to a recording head to record data to a heat-assisted recording medium for one or more iterations, each iteration comprising, via the recording head at each laser power increment:
- adjusting a linear data density of first data written to a single track of the recording medium to achieve a first bit error rate;
- and adjusting a track pitch of second data written to multiple tracks of the recording medium to achieve a second bit error rate;
- determining, from the iterations, a selected linear data density, a selected track pitch, and a selected laser power that together achieve a target areal density;
- and
- using the selected linear data density, the selected track pitch, and the selected laser power to write user data to the recording medium during operation of a hard disk drive that comprises the recording head and the recording medium.
3 more elements
A method comprising:
- finding a linear data density, a track pitch, and a laser power for initially writing to a heat-assisted recording medium at an initial areal density;
- for one or more iterations:
- adjusting the linear data density;
- determining an adjusted laser power at the adjusted linear data density to achieve a target bit error rate;
- determining an adjusted track pitch at the adjusted linear data density and the adjusted laser power;
- and
- determining an areal density using the adjusted linear data density, the adjusted laser power, and the adjusted track pitch;
- finding, based on the iterations, a local maximum areal density and a selected linear data density, a selected laser power, and a selected track pitch associated therewith.
5 more elements
Dependencies are inferred from the claim text.