| 摘要 |
PROBLEM TO BE SOLVED: To provide a recording medium having both an low cost and a high security and capable of realizing an operation system using recording medium, a recording device using the recording medium, and an admission/exit control system. SOLUTION: A card 2 is formed by stacking a colored security image 22 such as a bar code, a variable layer 23 having a reversely variable transmittance, a protective layer 24 having a transparency, an under-coated layer 25, and a magnetic recording layer 26. By making the variable layer 23 transparent, a security image 22 is brought into a visible display state or mechanically readable state, and the variable layer 23 is clouded to form an invisible non- display state or a mechanically unreadable state. The information obtained by processing the registered information registered beforehand with the security image 22 using as a key is stored in the magnetic recording layer 26. |
