| 摘要 |
PURPOSE:To reduce the generation of errors of a demodulated data by modulating and demodulating the data of a binary code with the correspondence secured between a prescribed signal wave and each of binary codes. CONSTITUTION:A signal wave 1 having the polarity inverted at time T is set opposite to the code of one side of a binary code; while a signal wave 4 having the polarity inverted at 1/4T is set opposite to the code of other side. The data modulated in such a way is recorded on a magnetic tape of tape cassette. When this data is modulated, it is discriminated that E has a change if the time between zero cross points of a reproduced output is shorter than F and that D has a change if said time is longer than F. In such way, the demodulation is possible although the tape travelling speed has a considerable degree of fluctuation. This can reduce the errors of a demodulated data. |
