| 摘要 |
A security device (1) for verifying an authenticity of a security document (100) comprises an at least partially transparent substrate (2) with a first surface (3) and a second surface (4). A first pattern (10) is arranged on the first surface (3). The first pattern (10) comprises at least a first region (11) and a second non-overlapping region (12). A second pattern (20) is arranged on said second surface (4). The second pattern (20) comprises at least a third region (23) and a fourth non-overlapping region (24). The first region (11) coincides with the third region (23) and the second region (12) coincides with the fourth region (24). Transmittances and reflectivities of the regions (11, 12, 23, 24) are selected such that in a transmission viewing mode, the regions are indiscernible whereas in a reflection viewing mode, the first region (11) is discernible from the second region (13). |
