| 摘要 |
PURPOSE:To discriminate false information at the time of using light irregular reflection substances such as ground glass by detecting collation information by a main light detecting element arranged in the sheduled direction and a sublight detecting element arranged in the direction different from the direction of diffracted light of a normal hologram. CONSTITUTION:A card 1 having collation information holds a normal hologram 2, which is provided with a light diffraction angle in the single direction of the collation information. A reproduction light source 6 is arranged at the side of an incident window 4 of a card insertion path 3, and a main light detecting element 7 and a sublight detecting element 8 are provided at the side of projecting window 5. The former 7 is arranged in the scheduled direction of the hologram 2, and the latter 8 is arranged at the dislocated place from the scheduled direction. Outputs of both elements 7 and 8 are processed by an invertor 9 and an AND gate 10, collation information is outputted from an output terminal 11 and false information detected in the element 8 is outputted from an output terminal 12. At the time of using ground glass instead of the hologram 2, false information can be effectively discriminated. |
