| 摘要 |
The present invention provides an authentication apparatus operative to determine the authenticity of a polymer film, comprising an optically-based measuring arrangement operative to measure a first effect influenced by a birefringence characteristic of said film and a second effect influenced by another optical characteristic of said film, and wherein said apparatus is operative to: compare a value, or range of values, representative of said first effect with a value, or range of values representative of a specified first effect corresponding to a predetermined birefringence characteristic of an authentic polymer film; compare a value, or range of values, representative of said second effect with a value, or range of values representative of a specified second effect corresponding to a predetermined other optical characteristic of an authentic polymer film; and output an authenticity signal indicative of authenticity or otherwise of said film based upon one or both of said comparisons. There are also provided one or more methods of determining the authenticity of a polymer film. |
