Truth and Denomination Discrimination of Notes using Surface Properties Evaluated by Scanning with Optical Fiber Feeler

Abstract

It is effective to use both inherent and genuine properties for a reliable discrimination of notes. When the surface of the note is scanned with the tip of an optical fiber feeler, peculiar vibration waveform correlated to various surface properties is measured. In this paper, a novel method to discriminate the truth and denomination of notes is proposed by analyzing this. Two matters can be evaluated independently. The first is the roughness property extracted from the stick-slip component with an undulation of the intaglio print, which is inherent in only genuine notes. Truth can be discriminated by evaluating whether the stick-slip component exists on print part of vibration waveforms. The second is the variable-density property extracted from the low-frequency component with a print pattern. Denomination can be discriminated by comparing the variable-density pattern with the data-base of it for each denomination of notes. An improved discrimination method is constructed by integrating the proposed two property evaluation methods, and its effectiveness has been confirmed from experimental results for both circulated and counterfeit notes.