COUNTERFEIT PREVENTION MEDIUM, READING SENSOR DEVICE FOR COUNTERFEIT PREVENTION MEDIUM AND READING METHOD OF THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a counterfeit prevention medium having a high counterfeit prevention effect.SOLUTION: The counterfeit prevention medium includes: at least two types of security sections 12, 13 having optical characteristics showing characteristic absorption in at least a part of a near-infrared wavelength range, which are disposed on one surface of a substrate 11 so as to overlap each other in adjoining portions; and a gradation section 14 composed of the overlapping portions of the two types of the security sections, in which one of or both of the security sections are graded from a dark color to a pale color.