| 摘要 |
Method of verifying the authenticity of a security document ( 1 ), the security document including a first at least partially transparent portion ( 7, 8 ) and an optical projection element ( 9 ) within or superposed with the first at least partially transparent portion ( 7, 8 ), the optical projection element ( 9 ) acting to transform a light beam ( 10 a) passing from a light beam source through said first at least partially transparent portion ( 7, 8 ) into a patterned beam ( 11 ) of selected design, the method including the steps of: positioning the security document such that the light beam is transmitted through the first at least partially transparent portion and the patterned beam is projected onto a viewing surface ( 14 ), and verifying the presence of a patterned image by the impingement of the patterned beam on the viewing surface ( 14 ).
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