Information playback apparatus with an unusual waveform circuit
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsAkira Kawabe, Koichi Nagano
Life of this patent
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Abstract
An unusual waveform detection circuit of the present invention is a digital-type unusual waveform detection circuit that arbitrarily sets a threshold used for determining an unusual waveform and produces an unusual waveform determination signal by comparing an input signal with the threshold. In producing the unusual waveform determination signal, one of a configuration where a voltage at each of all sampling points is compared with a reference voltage and a configuration where a continuously changing gradient of signal waveform peaks is calculated and is compared with a reference gradient is selectively employed. The unusual waveform detection circuit can easily and accurately detect various unusual waveforms.
Claims15
A digital-type unusual waveform detection circuit for detecting an unusual waveform of an analog playback signal, said unusual waveform detection circuit comprising:
- a digitizing unit for performing analog/digital conversion of the analog playback signal;
- a detecting unit for determining whether an input signal from said digitizing unit satisfies a preset input waveform condition and for outputting a determination signal;
- and
- a counting unit for counting the output from said detecting unit and outputting an unusualness detection signal when the count value exceeds a predetermined threshold.
An information playback apparatus for detecting an unusual waveform of an analog playback signal read out of a recording medium using an digital-type unusual waveform detection circuit,
- wherein the unusual waveform detection circuit detects an unusual waveform of an analog playback signal and includes:
- a digitizing unit for performing analog/digital conversion of the analog playback signal;
- a detecting unit for determining whether an input signal from the digitizing unit satisfies a preset input waveform condition and for outputting a determination signal;
- and
- a counting unit for counting the output from the detecting unit and outputting an unusualness detection signal when the count value exceeds a predetermined threshold.
Dependencies are inferred from the claim text.