| 摘要 |
An authentication apparatus 100 operative to determine the authenticity of an item 106 comprising a film substrate responsive to detection that a portion of said item located in a measuring region of said apparatus has a predetermined birefringence characteristic, determined by an optically-based birefringence measuring apparatus 102 (comprising emitter 110 and detector 114), said apparatus further operative to measure a reflection characteristic of said portion of said item located in a measuring region of said apparatus, determined by an optically-based reflectance measuring apparatus 104 (comprising emitter 126 and detector 128), wherein said apparatus 100 is operative to compare a measured birefringence characteristic with a predetermined birefringence characteristic and a measured reflection characteristic with a predetermined reflection characteristic, further wherein said apparatus 100 is operative to output an authenticity signal indicative of authenticity or otherwise of said item based upon said comparisons. A further apparatus comprising only the birefringence measuring apparatus and an item detection arrangement operative to control output of said authenticity signal is also disclosed. |
