Waveform equalizer for signal reproduced from a magnetic recording medium
AssigneeKabushiki Kaisha Toshiba
InventorsHiroshi Okamura, Hiroshi Suzuki
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Abstract
In a waveform equalizer of the present invention, first and second Hilbert-transform signals are formed from a parallel-reproduced signal, and a desired signal is obtained from these signals by an operational amplifier. The waveform equalizer includes a reflecting section having a plurality of resistors, and a switching section for selecting one of the resistors in accordance with a control signal. Therefore, the waveform equalizer can process a plurality of reproduced signals which have different ratios of the longitudinal signal component to the perpendicular signal component without being affected by inphase noise.
Claims14
A waveform equalizer for equalizing a waveform of a parallel signal reproduced from a magnetic record medium, comprising:
- delaying means including first and second delay lines each having a receiving end and a terminating end, for receiving the parallel-reproduced signal at said receiving ends, each of said first and second delay lines having at least one tap;
- reflecting means connected between said terminating ends, for reflecting a part of the parallel-reproduced signal supplied to said receiving ends and for transmitting a remaining part of the parallel-reproduced signal;
- first weighting means for weighting a first tap signal from said first delay line;
- second weighting means for weighting a second tap signal from said second delay line;
- first combining means for adding a first transmitted signal from the terminating end of said first delay line and the weighted first tap signal in accordance with a relation predetermined by the impedance of said reflecting means to produce a first Hilbert-transform signal;
- second combining means for adding a second transmitted signal from the terminating end of said second delay line and the weighted second tap signal in accordance with the predetermined relation to produce a second Hilbert-transform signal;
- and
- operation amplifier means for calculating the difference between the first and second Hilbert-transform signals.
A waveform equalizer for equalizing a plurality of reproduced signals, each having a different ratio of longitudinal signal component to perpendicular signal component, comprising;
- delaying means including a delay line having a receiving end and a terminating end, for receiving the reproduced signal at said receiving end, said delay line having at least one tap;
- reflecting means including a plurality of resistors for reflecting part of the reproduced signal supplied to said receiving end, a selected resistor from said plurality of resistors transmitting the remaining part of the reproduced signal, the terminating resistance of each of said resistors being selected by means of a control system such that the reflected signal at said terminating end has a polarity opposite to the reproduced signal supplied to said terminating ends;
- switching means for selecting one from the plurality of resistors in said reflecting means in accordance with a control signal;
- weighting means for weighting a tap signal from said delay line;
- and
- combining means for adding a transmitted signal from the terminating end of said delay line and the weighted tap signal in accordance with resistance of the selected resistor to produce a Hilbert-transform signal.
The waveform equalizer according to claim 12, wherein said weighting means further comprises first adding means for adding together the weighted tap signal.
Dependencies are inferred from the claim text.