Reader with linearizing bias current
AssigneeSeagate Technology LLC
InventorsVictor Sapozhnikov, Mohammed Sharia Ullah Patwari
Life of this patent
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Abstract
Disclosed are methods for linearizing the response of a non-linear magnetic reader, for example in the operation of a hard disk drive. Magnetic readers generally exhibit non-linearities in their response to an applied magnetic field, and those non-linearities may be particularly pronounced when the field strength is high. This deviation from linearity at larger field strengths can limit the useful range of field amplitudes. To expand the useful range of field amplitudes and thereby increase the available signal at the reader, the reader bias current may be varied in such a way to compensate for the natural non-linearity of the reader, thus making the reader output signal linear over a larger range of detected field strengths.
Claims19
A method for use with a hard drive that includes a reader for reading a data track from a magnetic storage medium by detecting magnetic field strength, where the reader exhibits a linear response over a first range of field strengths and exhibits a non-linear response over a second range of field strengths, the method comprising:
- adjusting a bias current of the reader to compensate for the non-linear response, thereby producing an approximately linear response over the first and second ranges of field strengths;
- and
- reading the data track from the magnetic storage medium using the reader.
A hard disk drive comprising:
- a recording head including a writer for writing data in a data track on a magnetic storage medium and a reader for reading data from the data track written on the magnetic storage medium, where the reader exhibits a non-linear response over a portion of a full range of field strengths;
- control electronics configured to vary a reader bias current to compensate for the non-linear response of the reader, thereby producing an approximately linear reader response over the full range of field strengths.
Dependencies are inferred from the claim text.