DEVICE FOR CHECKING VALIDITY OF BANKNOTE Russian patent published in 1998 - IPC

FIELD: bank equipment. SUBSTANCE: device has ultraviolet source with gas-discharge lamp, photodetector, power supply, actuating unit and comparator. Input window of photodetector is directed for receiving both power reflected from banknote under investigation and light of gas-discharge lamp. In saturation mode additional opaque wall may be mounted between gas-discharge lamp and input window of photodetector. Said wall is equipped with hole through which light of gas-discharge lamp is passed towards input window of photodetector. Area of window in wall conforms to condition excluding possibility of operation of photodetector in saturation mode in case of simultaneous receiving light of gas-discharge lamp through window in wall and power reflected from banknote under investigation with maximal amplitude values. EFFECT: increased validity of checking, decreased cost of manufacturing and repair. 2 cl, 1 dwg