| 摘要 |
A method and device for the identification of documents and banknotes marked with Optical Variable Inks providing: generating a white light ray between 5,000° and 7,000° K; polarizing that white light ray through a first polarizing filter ( 3 ), and sending the polarized ray ( 4 ) onto an area ( 5 ) to be assessed; filtering the ray ( 6 ) reflected the area ( 5 ) to be assessed by a second polarizing filter ( 7 ), in phase consistency with the first polarizing filter ( 3 ) and getting a first signal (s<SUB>a</SUB>); filtering the ray ( 6 ) reflected by the area ( 5 ) to be assessed by a third polarizing filter ( 8 ), in anti-phase with the first polarizing filter ( 3 ), and getting a second signal (s<SUB>b</SUB>); measuring the difference Delta between these two signals; comparing the calculated value Delta to a reference value Delta<SUB>r </SUB>previously measured on genuine documents and banknotes.
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