Patent ID: 7322530

Claim:
A method for the machine identification of a forgery-proof marking for an object, said forgery-proof marking comprising (a) a transparent film produced from plastic and having a first and second surface, (b) wherein said second surface comprises a series of layers whose color changes as a function of the viewing angle, wherein the series of layers is formed from an absorber layer, a spacer layer overlying the absorber layer and a mirror layer overlying the spacer layer, wherein the absorber layer comprises metallic clusters, said method having the following steps: a) registering a spectrum of light reflected by the forgery-proof marking at a predefined viewing angle, b) measuring values for determining (i) a position and/or (ii) a shape and/or (iii) an intensity of one or more absorption peaks characteristic of the marking within a predefined spectral range, c) comparing the values (i) to (iii) measured in step b) with predefined corresponding values, and d) identifying the marking by using results of the comparison.