CURRENCY NOTE IDENTIFICATION SYSTEM

This disclosure concerns currency identification systems for examining an authenticity characteristic of a detected currency and comparing it to an authenticity characteristic of a genuine currency to determine if the detected currency is genuine. The systems comprises memory means for storing a series of first electrical signals representing the authenticity characteristic of the genuine currency, each of the first signals corresponding to a discrete successive area of the genuine currency and representing a component of a first authenticity vector, detecting means for scanning the detected currency and generating a series of second electrical signals representing the authenticity characteristic of the detected currency, each of the second signals corresponding to a discrete successive area of the detected currency and representing a component of a second authenticity vector, calculating means coupled to the detecting means and the memory means to calculate a value of similarity corresponding to an angle between the first authenticity vector and the second authenticity vector, and comparing means for comparing the value of similarity with a predetermined value which represents a permissable authenticity value for the detected currency corresponding to a genuine currency.