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US 6,191,905 B1Granted
Magnetic disc apparatus
AssigneeNEC Corporation
InventorToshio Takeuchi
Life of this patent
Estimating the term…
Abstract
The present invention provides a magnetic disc apparatus comprising: a magnetic disc and a signal processor having functions of (i) setting measurement points at an interval which is smaller in the vicinity of an initial position of a window than in the vicinity of the maximum modification position; (ii) shifting the window from the initial position up to the maximum modification position; (iii) each time the window position is shifted according to the aforementioned interval, reproducing a check data recorded on the magnetic disc, so as to measure an error rate; and (iv) using the error rate measurement results so as to obtain an optimal position of the window.
Claims9
A magnetic disc apparatus comprising:
- a reproduction head for reproducing a data recorded on a magnetic disc;
- and
- a signal processor for shaping a reproduction signal reproduced by the reproduction head and generating a pulse from the reproduction signal by using an optimized window,
- the signal processor having functions of
- (i) setting measurement points at an interval which is smaller in the vicinity of an initial position of a window than in the vicinity of a maximum modification position;
- (ii) shifting the window from the initial position up to the maximum modification position;
- (iii) each time the window position is shifted according to the aforementioned interval, reproducing a check data recorded on the magnetic disc, so as to measure an error rate;
- and
- (iv) using the error rate measurement results so as to obtain an optimal position of the window.
6 more elements
A magnetic disc apparatus comprising:
- a magnetic disc for recording a data;
- a reproduction head for reproducing a data recorded on the magnetic disc;
- and
- a signal processor for shaping a reproduction signal reproduced by the reproduction head and generating a pulse from the reproduction signal by using an optimized window,
- the signal processor including:
- (i) means for setting measurement points at an interval which is smaller in the vicinity of an initial position of a window than in the vicinity of a maximum modification position;
- (ii) means for shifting the window from the initial position up to the maximum modification position;
- (iii) means for reproducing a check data recorded on the magnetic disc so as to measure an error rate each time the window position is shifted according to the aforementioned interval;
- and
- (iv) means for using the error rate measurement results to obtain an optimal position of the window.
7 more elements
A magnetic disc apparatus comprising:
- a magnetic disc for recording a data;
- a reproduction head for reproducing a data recorded on the magnetic disc;
- and
- a signal processor for shaping a reproduction signal reproduced by the reproduction head and generating a pulse from the reproduction signal by using an optimized window,
- the signal processor having functions of
- (i) setting measurement points at an interval which is smaller in the vicinity of an initial position of a window than in the vicinity of a maximum modification position;
- (ii) shifting the window from the initial position up to the maximum modification position;
- (iii) each time the window position is shifted according to the aforementioned interval, reproducing a check data recorded on the magnetic disc, so as to measure an error rate;
- (iv) plotting the error rates obtained at the respective measurement points in the left (minus) side and the right (plus) side of the window initial position, so as to obtain a left plot curve and a right plot curve;
- (v) determining a distance between the left plot curve and the right plot curve at a target error rate, as a width of the window;
- and
- (iv) determining the position where the window width has been obtained, as a position of the window.
9 more elements
A magnetic disc apparatus comprising:
- a magnetic disc for recording a data;
- a recording/reproduction head for reproducing the data recorded on the magnetic disc and recording a data onto the magnetic disc data;
- and
- a signal processor for shaping a reproduction signal reproduced by the recording/reproduction head and controlling recording operation of the recording/reproduction head,
- wherein the signal processor includes:
- an active filter for shaping a waveform of a reproduction signal;
- a data synchronizer and a peak detector for producing a pulse from the signal output from the active filter;
- a recording controller for controlling a recording pulse timing and a recording current value,
- the signal processor further including:
- means for setting a cut-off frequency (fc), Boost, and delay (DLY) serving as parameters for controlling the characteristic of the active filter;
- means for setting the slice level (SLV) in the peak detector;
- means for setting the window shift in the synchronizer;
- means for setting a write pre-compensation serving as a timing of the write pulse of the recording controller;
- and means for setting a write current (Ic),
- wherein the signal processor determines an error rate according to possibility of mismatch between a read-out signal and a write-in signal while modifying the window shift setting and, for window margin calculation at a predetermined error rate (E1), sets measurement points at a smaller interval in a region around the window center than in a region far from the window center.
12 more elements
Dependencies are inferred from the claim text.