| 摘要 |
The invention relates to a security document comprising a substrate 4 which is provided with a security feature. According to the invention, the security feature comprises an arrangement of optical elements 2 within a predetermined area 32, 34 of the security document, wherein each of said optical elements 2 forms an optical reflector and wherein each of said optical elements 2 comprises a stack of curved alternating layers 10 of different refractive indices. The optical reflector changes its appearance depending on the type of incident illumination. When viewed from any direction under diffuse white incident illumination, the optical reflector has the appearance of a single dull colour, while under directional white incident illumination a bright sparkling effect is observed. |
