METHOD AND DEVICE FOR DISCRIMINATING CARD

PROBLEM TO BE SOLVED: To accurately discriminate the authenticity of a card without being influenced by the variation of a carrying speed. SOLUTION: In the card discrimination device 20, data are recorded on a 2nd track 3 of a card after recording data on a 1st track 2, and at the time of simultaneously reproducing data from the 1st and 2nd tracks 2, 3, the bit interval of a reproduced signal reproduced from the 1st track 2 at prescribed timing is compared with that of a reproduced signal from the 2nd track 3 and an identification(ID) code corresponding to the compared result is recorded on a 3rd track 4 of the card to issue the card. At the time of using the card, at least the 1st and 2nd tracks 2, 3 of the card are simultaneously reproduced by a magnetic head 21, bit intervals are respectively detected from the peak timing of respective reproduced signals, the bit interval (p) of the 1st track 2 detected at the prescribed timing is compared with the bit inteval (q) of the 2nd track 3 and a detection code corresponding to the compared result is compared with the ID code recorded on the 3rd track 4 to discriminate the authenticity of the card.