| 主权项 |
1. A security document having a first side and a second side, the security document comprising: a first pattern and a second pattern located closer to the second side than the first pattern, the first pattern and the second pattern overlapping such that the overlapping area defines a shape of a security pattern , the security pattern being adapted to be irradiated with an excitation radiation from at least direction of the first side, wherein the first pattern comprises first single fluorescent substance adapted to emit first visible light, and the second pattern comprises second single fluorescent substance adapted to emit second visible light, both the first pattern and the second pattern having an excitation spectrum which has a substantially lower value at a frequency of a first excitation radiation than at a frequency of a second excitation radiation, the excitation spectrum of the second pattern having a substantially higher value than the excitation spectrum of the first pattern at the frequency of the second excitation radiation the security pattern having a first transmittivity coefficient for the first side and the first excitation radiation, and a second transmittivity coefficient for the first side and the second excitation radiation selected in such a relation to the values of the excitation spectra of the first pattern and the second pattern that when the security pattern is irradiated from the direction of the first side the first visible light dominates the second visible light at the first excitation radiation and the second visible light dominates the first visible light at the second excitation radiation. |
