Tar with write-synchronized laser modulation
AssigneeHGST Netherlands B.V.
InventorsHans J. Richter, Erhard Schreck, Matteo Staffaroni, Barry C. Stipe
Life of this patent
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Abstract
Instead of using discontinuous step functions or pulses to drive a laser of a TAR enabled disk drive between on and off, a fixed modulation frequency may be used that alternates between a high and low laser power such that the radiation source is always delivering heat to the magnetic media when writing data to the magnetic disk. The magnetic field of the write pole may be synchronized to the modulation frequency of the radiation source to ensure that the radiation source heats the magnetic media proximate to the write pole above the grain freezing temperature when the Zeeman energy produced by the magnetic field of the write pole exceeds the thermal energy of the magnetic media.
Claims19
A method for performing thermal assisted recording in a hard disk, comprising:
- modulating a radiation source that heats a magnetic media in the hard disk drive, wherein a modulation frequency of the radiation source is greater than a maximum data frequency at which a write pole writes data onto the magnetic media, and wherein, while the write pole writes data to the magnetic media, the modulation frequency is fixed;
- and
- biasing the radiation source with a DC current thereby providing a DC bias to the modulation frequency.
A disk drive configured to perform thermal assisted recording, comprising:
- a radiation source configured to heat a magnetic media in the disk drive;
- a driver circuit configured to modulate the radiation source, wherein a modulation frequency of the radiation source is greater than a maximum data frequency at which a write pole writes data onto the magnetic media, and wherein, while the write pole writes data to the magnetic media, the modulation frequency is fixed, the driver circuit is configured to bias the radiation source with a DC current thereby providing a DC bias to the modulation frequency.
A driver circuit for modulating a radiation source configured to heat a magnetic media in a disk drive when performing thermal assisted recording, comprising:
- modulation circuitry configured to generate a signal to modulate the radiation source, wherein a modulation frequency of the radiation source is greater than a maximum data frequency at which a write pole writes data onto the magnetic media, and wherein, while the write pole writes data to the magnetic media, the modulation frequency is fixed;
- and
- biasing circuitry configured to bias the radiation source with a DC current thereby providing a DC bias to the modulation frequency.
Dependencies are inferred from the claim text.