Patent ID: 9666009
Date: 2017-05-30
CPC Classifications: G01N,G02B,G06K,G07D

Claim:
1. An authentication apparatus operative to determine the authenticity of a polymer film, comprising: an optical response modifier operative to modify a first effect influenced by said birefringence characteristic of said film to a modified first effect; and an optically-based birefringence measuring arrangement operative to measure said modified first effect; and wherein said apparatus is operative to: compare a value, or range of values, representative of said modified first effect as measured with a value, or range of values representative of a specified first effect as modified by a same optical response modifier and corresponding to a predetermined birefringence characteristic of an authentic polymer film; and output an authenticity signal indicative of authenticity or otherwise of said film based upon said comparison(s), wherein said optical response modifier provides a different birefringence scale compared with an apparatus which does not have such an optical response modifier, and wherein said optically-based birefringence measuring arrangement comprises: wherein said processor is operative to compare said values and output the authenticity signal indicative of authenticity or otherwise of said film based upon said comparison(s).