| 摘要 |
The data carrier (1) includes an optically variable element (2) having a metallic area (3) which reflects light falling onto it in a directional manner. The area has a saw-tooth profile or has a diffraction grating. It is combined with a light diffusing surface (4) to create markings which are recognised optically. The characteristics of the two areas are such that the intensity of the reflected light is higher than the intensity of the light radiated from the diffusing surface when viewed from at least one angle of observation. It is lower when viewed from at least one other angle of observation. The diffusing surface has a white, yellow, light blue or pastel colour. |
