Patent ID: 7478757
Filing Date: 2009-01-20
Classification: G06K,G07D

Abstract:
1. A method for determining the authenticity of an item, the item carrying a marking exhibiting a viewing-angle dependent light reflection spectrum, the method comprising steps of a) illuminating said marking with at least a first light source having first spectral characteristics; b) collecting light reflected by said marking at least at two predefined different observation angles with respect to the plane of the marking, and measuring its respective intensity; c) illuminating said marking with at least a second light source having second spectral characteristics; d) collecting light reflected by said marking at least at two predefined different observation angles with respect to the plane of the marking, and measuring its respective intensity; and e) comparing said measured intensity values of steps b) and d) with previously stored corresponding reference values according to a predefined algorithm, and deriving an authenticity indicator from the comparison result using a preestablished decision criterion; wherein the illumination in each of steps a) and c) is a wide-angle illumination provided through a Compound Parabolic Concentrator (CPC).