| 摘要 |
A security device (2) including a substantially transparent material (6) having a first side and a second side. An array of lenses (4) is arranged on the first side of the material (6) and an ablative layer (8), which is reflective or at least partially opaque, is arranged on the second side of the material. The ablative layer has one or more patterns (12, 16) formed by removal of the ablative layer, for example by laser radiation (10, 14). The or each pattern (12, 16) is viewable at a particular viewing angle (&thetas;, &phgr;) or range of angles through the array of lenses. Also disclosed is a method of manufacturing a security device. |
