摘要 |
An improved optical sensor for a banknote validator uses an aspherical lens having a planar wall as a combination radiation plug for a port in the pathway and a focusing arrangement. Emitters and receivers are closely positioned on a common support and generally located at the focal point of the lens. The radiation reflected by a banknote is focused and received by the receiver. The lens also serves to collimate the produced radiation of the emitters for scanning of the banknote. |