| 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. |
