| 摘要 |
A laminated tamper evident security document (10) is provided which has a transparent or translucent support layer (12), first and second security layers (16, 16') on opposite sides of the support layer (12), first and second tamper evident layers (14, 14') between the support layer (12) and the security layers (16, 16') layers of printed information (22) over the security layers (16, 16') and polymeric outer layers (18). The security layers (16, 16') have security regions (26, 26') which together form a composite security device or image (30) to indicate an authentic security state. Upon exposure to predetermined conditions to delaminate the document, at least one of the tamper evident layers (14, 14') is arranged to destruct or otherwise affect at least one of the security layers (16, 16') to indicate an unauthentic state. In one embodiment each of the tamper evident layers (14, 14') are formed from a weakly coherent or adherent material having a glass transition temperature lower than that of the other layers so that the tamper evident layer (14) separates a portion of the document containing one of the security layers (16) from the remainder of the security document (10) containing the other security document. |
