Patent ID: 8917386
Filing Date: 2014-12-23
Classification: G01J,G07D,G07G

Abstract:
1. A method for checking the authenticity of a value document, involving capturing and evaluating electromagnetic radiation passing through the value document, the method comprising the steps: capturing in locally resolved fashion at least one intensity distribution of electromagnetic radiation in dark field and determining a locally resolved dark field characteristic from the at least one captured intensity distribution; assigning selected partial check regions of the value document to respectively one of several preset suspicion classes in dependence on a comparison of a characteristic intensity value of the dark field characteristic of the respective partial check region with at least one upper and/or lower threshold value; forming an interrelation region by aggregating substantially interrelated partial check regions which have been previously assigned to at least one certain suspicion class; assigning the value document to one of at least two preset authenticity categories linked with the at least one certain suspicion class, in dependence on a form and/or location of the interrelation region, wherein capturing in locally resolved fashion the at least one intensity distribution of electromagnetic radiation in dark field includes measuring electromagnetic radiation scattered by the value document, scattered electromagnetic radiation being electromagnetic radiation that is transmitted through the value document at an angle that is sufficiently different from an angle of transmitted electromagnetic radiation that passes through the value document in substantially a straight line.