| 摘要 |
A security device (20) is provided, comprising a first transparent layer (21) having an optically variable effect generating relief structure (22) formed in a surface thereof; a reflection enhancing layer (23) extending over the relief structure and following the contour of the relief; and a second transparent layer (24) extending over the reflection enhancing layer, the lateral extent of the second transparent layer being less than the whole area of the security device and corresponding to the lateral extent of the reflection enhancing layer. The first and/or second transparent layer comprises one or more optically effective substances such that the appearance of the optically variable effect generated by the relief structure is different when viewed through the first transparent layer compared with when viewed through the second transparent layer, at least under illumination at a wavelength at which at least one of the optically effective substance(s) is visible. |
