Dynamic magnetic information storage or retrieval – General processing of a digital signal – Head amplifier circuit
Patent
1996-01-02
2000-07-11
Faber, Alan T.
Dynamic magnetic information storage or retrieval
General processing of a digital signal
Head amplifier circuit
360 75, 360 25, 360 31, G11B 509
Patent
active
060881763
ABSTRACT:
An apparatus and method for reading an information signal from a magnetic storage medium using a magnetoresistive (MR) head, and separating a thermal signal component and, if present, a magnetic signal component from the information signal. A signal separation/restoration module eliminates distortion in the magnetic signal component of a readback signal induced by a thermal signal component of the readback signal. A finite impulse response (FIR) filter may be employed in the signal separation/restoration module to eliminate the distortion in the magnetic signal. The signal separation/restoration module may be employed to extract the thermal signal component from the readback signal. In one configuration, an MR head is coupled to an arm electronics (AE) module, having a highpass filtering behavior, and a signal separation/restoration module that includes an inverse filter having a transfer function inverse to that of the effective highpass filter of the AE module. The inverse filter may be an infinite impulse response (IIR) filter. In another embodiment, the magnetic and thermal signal components of a readback signal are respectively extracted and processed so as to linearly correspond to head-to-disk spacing. Head-to-disk spacing change using the thermal signal is used to detect disk surface defects, topographic variations, and servo control surface variations.
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Abraham David William
Ottesen Hal Hjalmar
Praino Anthony Paul
Re Mark Edward
Smith Gordon J.
Faber Alan T.
Hollingsworth Mark A.
International Business Machines - Corporation
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