Patent attributes
A fraud detection system for a self-service terminal which has a card reader includes an optical proximity sensor and an electrode for a capacitive proximity sensor mounted adjacent to a slot in the card reader. A controller is coupled to the optical proximity sensor and the capacitive proximity sensor. The controller compares a proximity signal from the optical proximity sensor with a first predetermined proximity threshold that is adjusted based on a level of ambient infrared light at that sensor, and sets an alarm signal when an object is closer than the adjusted first predetermined proximity threshold. The controller also compares a proximity signal from the capacitive proximity sensor with a second predetermined proximity threshold that is adjusted based on a level of luminosity light at the optical proximity sensor, and sets an alarm signal when an object is closer than the adjusted second predetermined proximity threshold.
