GENUINENESS DETERMINATION METHOD FOR PRINTING MEDIUM, IMAGE PROCESSING INSPECTION SYSTEM SUITABLE THEREFOR, AND PRINTING MEDIUM

PROBLEM TO BE SOLVED: To provide a genuineness determination method for a printing medium, capable of determining easily genuineness at relatively low cost without requiring high printing precision, while made difficult to be forged, an image processing inspection system suitable therefor, and a printing medium hardly to be forged. SOLUTION: The first pattern is printed on a surface of the printing medium 2, using ink absorbing or reflecting a visible ray, the second pattern different from the first pattern is printed on the surface of the printing medium 2 or a surface of a translucent film covering the surface, using, for example, ink absorbing or reflecting an invisible infrared ray, the surface of the printing medium 2 or the like is irradiated with only the infrared ray from a lighting system 12, under a visible ray shielded condition, the surface of the printing medium 2 or the like is imaged using an imaging device 13 under the condition, the printing medium 2 is determined as a true object when the presence of the second pattern is confirmed in an image data output from the imaging device 13, and is determined as a forgery when not so. COPYRIGHT: (C)2010,JPO&INPIT