| 摘要 |
Security device having changing appearance when viewed at a tilted angle along a first axis and a second axisA security device 10 comprises a first pattern of elements P1 and a second, overlapping, pattern of elements P2 spaced by a transparent layer 1, the combination of first P1 and second P2 patterns obstructing the passage of light through the device to a varying degree depending on the viewing position; the device includes a first region of patterns where the maximum change in obstruction of light occurs when the device is tilted along a first axis TA1 and a second region where the maximum change in obstruction of light occurs when the device is tilted along a second axis TA2 which is not parallel to the first axis. Other security devices are also disclosed: security devices including regions which have a maximum obstruction of light when viewed from different positions; security devices including a pattern of elements and a reflective surface separated by a transparent layer and security devices comprising patterns of elements including cut outs. |
