| 摘要 |
PURPOSE:To enhance a falsification preventive function by providing a magnetic recording part formed by mixing plural magnetic material having different coercive forces to a titled medium. CONSTITUTION:Magnetic recording is executed by impressing the magnetic field sufficiently strong to magnetize the high-coercive force magnetic material to saturation to the recording medium by a magnetic head 30 for strong magnetic field. Another data is then multiple-recorded magnetically by impressing the weak magnetic field of the extent at which the low-coercive force magnetic material can be magnetized and to influence is exerted to the magnetization condition of the high-coercive force magnetic material by a magnetic head 32 for weak magnetic field. The magnetization pattern or the high-coercive force magnetic material is shown by the lines inclining upward to the right and the magnetization pattern for the low-coercive force magnetic material are shown by the lines inclining upward to the left. Data of twice the data in an ordinary case can be recorded in one track in this case and the overlapped data conceal each other. The recording data in the respective magnetization directions are reproduced by reproducing heads 34, 36 in the gap directions corresponding to the magnetization directions of the respective coercive force magnetic materials irrespectively of sequence at the time of reproduction.
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