Magnetic card reader and magnetic data reproduction method using signal peak point intervals

A magnetic data reproduction method of causing a magnetic card to make a move relative to a magnetic head and reproducing data on the magnetic card by the magnetic head, said magnetic data reproduction method comprising the steps of:

• reproducing digital data based on the interval between peak points detecting from output of a magnetic signal provided by the magnetic head;
• detecting an anomaly of the peak point interval;
• converting the output of the magnetic signal provided by the magnetic head from analog form into digital form every predetermined time and storing the provided data,
• wherein, in said data reproduction step, a reproduction portion detected in said anomaly detection step uses the data provided in said output value storage step.

A data demodulation method of magnetic record data for demodulating magnetic data information made of “0” signal or “1” signal based on interval data provided by detecting a peak position in a reproduction signal of magnetic record data written to a magnetic record medium and counting the time interval between the adjacent peak positions, said data demodulation method comprising the steps of:

• classifying all interval data concerning the peak positions of the reproduction signal into three categories of “0” data, “1” data, and “gray zone” data undefined as the “0” data or the “1” data;
• performing smoothing processing for the categories of the “0” data and the “1” data, thereby finding two smoothed curves;
• averaging the two smoothed curves, thereby finding and setting a threshold curve for classifying data into the “0” data and the “1” data;
• and
• making binarization determination of all the interval data using the setup threshold curve.

A data demodulation method of magnetic record data for demodulating magnetic data information made of “0” signal or “1” signal based on peak interval data provided by detecting a peak position in a reproduction signal of magnetic record data written to a magnetic record medium and counting the time interval between the peak positions, said data demodulation method comprising the steps of:

• converting the reproduction signal of the magnetic record data from analog form into digital form to find a reproduction curve of digital data, performing integration calculation of the digital data forming the reproduction curve, thereby finding an integration curve, using a maximum value and a minimum value on the integration curve to find a curve representing an average value of the integration curve;
• subtracting the average value from each value of the integration curve, thereby finding an average integration curve;
• and
• demodulating the magnetic data information made of the “0” signal or the “1” signal based on the average integration curve.

A data demodulator of magnetic record data for demodulating magnetic data information made of “0” signal or “1” signal based on peak interval data provided by detecting a peak position in a reproduction signal of magnetic record data written to a magnetic record medium and counting the time interval between the peak positions, said data demodulator comprising:

• an A/D conversion section for converting the reproduction signal from analog form into digital form, thereby outputting a digital reproduction signal;
• an addition waveform generation section for adding data of the digital reproduction signal from said A/D conversion section to generate an addition waveform;
• an integration waveform generation section for removing low-frequency noise from output of said addition waveform generation section and generating an integration waveform;
• and
• a digital type peak detection section for detecting a peak position of the digital reproduction signal based on output of said integration waveform generation section.