| 摘要 |
PROBLEM TO BE SOLVED: To prevent a recording medium from being forged or frauduently altered by comparing individual medium information stored in a reader with electromagnetic wave information detected by irradiating the recording medium with an electromagnetic wave and judging the authenticity of the recording medium. SOLUTION: The recording medium 10 is irradiated with an electromagnetic wave radiated from an electromagnetic wave irradiation device 20, the reflected electromagnetic wave is detected by an electromagnetic wave detector 31, amplified by an amplifier 32 and converted into a digital signal by an A/D converter 33 and the digital signal is inputted to a CPU 34. The individual information of the medium 10 has been recorded in the CPU 34. The authenticity of the medium 10 is judged by comparing the electromagnetic wave information of the medium 10 obtained from an electromagnetic wave absorbing layer and an electromagnetic wave reflecting layer with the indivisual medium information stored in the CPU 34. Since plural security means are prepared, the recording medium can be prevented from being forged or frauduently altered. |
