Patent ID: 8610893
Filing Date: 2013-12-17
Classification: B41M,G07D

Abstract:
1. A process for detecting a marking on an article, comprising: a. marking the article, by contacting the article with at least one marker, wherein an absorption spectrum of the at least one marker has at least one narrow band with a half-height width of <1500 cm b. irradiating the article with electromagnetic radiation comprising a wavelength range which at least partly overlaps with the at least one narrow band of the at least one marker, c. optionally, during step b., effecting a change in a position of the at least one narrow band by a solvatochromic, electrochromic, photochromic or thermochromic effect, d. determining wavelength absorption by the article in a range comprising the wavelength range which at least partly overlaps with the at least one narrow band of the at least one marker, and e. detecting a marking on said article from said wavelength absorption, wherein the irradiation of the article with electromagnetic radiation is performed using at least two narrow-band radiation sources, switching back and forth between a wavelength at which the marker absorbs and a wavelength at which there is no absorption.