device for testing coins and in particular for the examination of the physical characteristics of the edge of a coin

摘要

A coin testing device for discriminating between an acceptable coin and an unacceptable coin of similar diameter but having a different edge characteristic. The device comprises a coin passageway defining a path along which coins pass through the device. A light source positioned to throw light on the edge of a coin as it passes along the coin passageway and a light sensor is positioned to receive light reflected from the edge of an acceptable coin as it moves along the coin passageway. Means are provided for examining a time-dependent quality of the reflected light received by the sensor such as the duration or the number of pulses and for comparing the value of the quality with the value for an acceptable coin.