Method and device for assessing the authenticity of bank notes with security windows

摘要

The method involves providing the banknotes (1) with bank note substrate having an opaque layer (6,7) for absorbing ultraviolet radiation. The sensitivity of the sensor in the area of the wave length of the stimulating radiation, is smaller than the sensitivity of the sensor in the area of the radiation which is generated by the banknote. The wave length of the stimulating radiation lies above the sensitivity area of the sensor. An independent claim is also included for a device for verifying the authenticity of banknotes.