| 摘要 |
PROBLEM TO BE SOLVED: To form a diffraction grating code and Fresnel hologram code molded body with which reading of a recording part of the code is made impossible through heading or the like by a thermal head. SOLUTION: An evaporation reflection layer 6 of tin or the like capable of suffering from cohesive failures through application of thermal energy or application of laser beam energy by a thermal head 11 is formed in a security code part with the interference fringe of a hologram or grates of diffraction grating as minute uneven patterns recorded on the surface of a resin layer 4, and code information recorded on the security code part can be read by light that is reflection diffracted from the reflection layer 6 prior to breaking the reflection layer 6, and further since light reflection diffracted from the reflection layer 6 attenuates beyond a predetermined value after cohesive failures of the reflection layer 6 through application of thermal energy or laser beam energy, code information recorded on the security code part becomes impossible of reading substantially. |
