Method to determine temperature dependent write pre-compensation in a hard disk drive
AssigneeMatsushita Electrical Industrial Co., Ltd.
InventorFumitoshi Hidaka
Life of this patent
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Abstract
Methods in accordance with the present invention can include determining a plurality of sets of write pre-compensation parameters. At baseline conditions, the hard disk drive can apply a first current and write pre-compensation parameters can be tuned to generate a desired write current waveform that can be applied to the read/write head to generate a magnetic field to define magnetization on the magnetic media. The hard disk drive can then apply a second current and write pre-compensation parameters can be tuned to generate the desired write current waveforms. A plurality of write pre-compensation parameters can then be generated based on the results for a plurality of corresponding temperatures and/or temperature ranges.
Claims15
A method to determine a low temperature set of write pre-compensation parameters for use in generating a write current waveform at a low temperature for a read/write head in a hard disk drive including a rotatable medium having a magnetizable material, the method including:
- applying a first write current to the read/write head;
- tuning the read/write head to obtain a first set of write pre-compensation parameters;
- applying a second write current to the read/write head;
- tuning the read/write head to obtain a second set of write pre-compensation parameters;
- determining the low temperature set of write pre-compensation parameters based on the first set and second set of write pre-compensation parameters.
A method to determine a plurality of sets of write pre-compensation parameters for use in generating a write current waveform at a low temperature for a read/write head in a hard disk drive including a rotatable medium having a magnetizable material, the method including:
- applying a first write current to the read/write head;
- tuning the read/write head to obtain a first reference set of write pre-compensation parameters;
- applying a second write current to the read/write head;
- tuning the read/write head to obtain a second reference set of write pre-compensation parameters;
- determining the plurality of sets of write pre-compensation parameters based on the first reference set and second reference set of write pre-compensation parameters.
A method to determine a plurality of sets of write pre-compensation parameters corresponding to a plurality of operating temperature ranges for use in generating a write current waveform for a read/write head in a hard disk drive including a rotatable medium having a magnetizable material, the method including:
- measuring a first temperature of the rotatable medium;
- applying a first write current to the read/write head;
- tuning the read/write head to obtain a first reference set of write pre-compensation parameters;
- measuring a second temperature of the rotatable medium;
- applying a second write current to the read/write head;
- tuning the read/write head to obtain a second reference set of write pre-compensation parameters;
- and
- determining the plurality of sets of write pre-compensation parameters based on the first reference set and second reference set of write pre-compensation parameters;
- wherein one of the first write current and the second write current is lower than the other of the first write current and the second write current.
Dependencies are inferred from the claim text.