| 摘要 |
PROBLEM TO BE SOLVED: To disable the illegal recording and reproducing of information by allowing light to passing through onto a light transparent substrate and forming at least one kind of the films of a refractive index different from that of the substrate so as to record information in the film. SOLUTION: On the substrate 2 consisting of the matter of a large refractive rate, a recording pattern layer 1 is generated from the matter of a refractive index smaller than it. Then, as incident light passing through the layer 1 is reflected by the substrate 2 at the time of putting light A4 on the layer 1 and this reflected light can be detected by a light sensor A7, the layer 1 can be used as a recording medium. On the other hand, by a light source B6 for transmitted light provided for the rear face of a face applying the reflected light to a recording card 5, light is vertically irradiated and transmitted through a light sensor B8. Consequently, even at the time of constituting a reflecting pattern by an aluminum foil which is used for forgery, the aluminum foil does not transmit light and discriminated as a forged card. |
