Information reproducing method and information reproducing device

An information reproduction method for reproducing digital signals with a reproduction head from an information recording medium, the method comprising:

• waveform-equalizing a reproduction signal with a waveform equalizer;
• detecting with a defect detector, from the reproduction signal, a signal portion reproducing a defect portion on a surface of the information recording medium and outputting a defect detection signal;
• performing the adaptive learning operation with an adaptive learning device, renewing the equalization properties of the waveform equalizer using an adaptation algorithm while changing an update amount of the equalization properties in accordance with the defect detection signal;
• and
• demodulating an output of the waveform equalizer with a demodulator.

An information reproduction method for reproducing digital signals with a reproduction head from an information recording medium, the method comprising:

• storing a reproduction signal in a memory and waveform-equalizing the reproduction signal with first waveform equalization properties;
• performing an adaptive learning operation, in which the first waveform equalization properties are renewed with an adaptation algorithm;
• after the adaptive learning operation, setting second waveform equalization properties to the first waveform equalization properties;
• reading out the reproduction signal from the memory and waveform-equalizing it with the second waveform equalization properties;
• and
• demodulating the reproduction signal after it has been waveform-equalized with the second waveform equalization properties.

An information reproducing device for reproducing digital signals with a reproduction head from an information recording medium, the device comprising:

• a memory for storing a reproduction signal;
• a first waveform equalizer for waveform-equalizing the reproduction signal;
• an adaptive learning device for performing an adaptive learning operation of renewing equalization properties of the first waveform equalizer with an adaptation algorithm;
• a second waveform equalizer for waveform-equalizing a signal read out from the memory, after the adaptive learning operation has been performed for the first waveform equalizer, and the equalization properties of the first waveform equalizer have been set as the equalization properties of the second waveform equalizer;
• and
• a demodulator for demodulating an output of the second waveform equalizer.

An information reproducing device for reproducing digital signals with a reproduction head from an information recording medium, the device comprising:

• a waveform equalizer for waveform-equalizing a reproduction signal;
• a defect detector for detecting, from the reproduction signal, a signal portion reproducing a defect portion on a surface of the information recording medium and outputting a defect detection signal;
• an adaptive learning device for performing an adaptive learning operation of renewing the equalization properties of the waveform equalizer using an adaptation algorithm and changing an update amount of the equalization properties in accordance with the defect detection signal;
• and
• a demodulator for demodulating an output of the waveform equalizer.