methods to check the authenticity of banknotes, particularly for vending machines, and banknotenpruefgeraet

摘要

A process and an apparatus for testing bank notes for their genuineness, particularly for automatic vending machines, wherein the bank note is illuminated from one side from a light source through a mask. The printed image on one side of the bank note is divided by the mask into several test fields. The reflected light from each test field is received by one of a plurality of large area photoelectric cells, which are so connected that departures from a given value are added together to form an error signal.