Channel postamble extension to de-gauss pole tips
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United States of America Patent
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Apr 7, 2009
Grant Date -
N/A
app pub date -
May 18, 2006
filing date -
May 19, 2005
priority date (Note) -
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status (Latency Note)
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Abstract
A technique for de-gaussing the pole tips and yoke of a write transducer in a perpendicular magnetic recording system is provided. An oscillator in the read channel is configured to produce an adjustable signal pattern output to the preamplifier when a write operation ends for a given time and at a predetermined frequency, such that as the preamplifier write current decays, it decays with transitions (polarity reversals). This results in a decaying AC field being applied to the write transducer at the end of a media write operation, effectively de-gaussing it and reducing the effects of remanent magnetization remaining in the poles and yoke of the magnetic recording head after a write current is turned off. This defeats a potential pole tip lockup or yoke lockup circumstance in the magnetic recording media which can result in an inability to write further data or a possible erasure of valid data on the hard disk with which the write head is associated.
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Patent Citation Ranking
- 7 Citation Count
- G11B Class
- 4.92 % this patent is cited more than
- 16 Age