Patent ID: 8251282

Claim:
A card reader device comprising: a card entrance for receiving a card; a card enclosure in registration with the card entrance and defining an area in which the card is read, the card enclosure including an entrance slot for receiving the card from the card entrance; a read/write head in the card enclosure; a card transport mechanism for drawing the card into the card enclosure through the entrance slot and along a path to the read/write head and for ejecting the card from the entrance slot, the card transport mechanism including a first pair of rollers adjacent the entrance slot and a second pair of rollers adjacent the read/write head, the first pair of rollers transporting the card to the second pair of rollers following receipt of the card and the second pair of rollers transporting the card to the first pair of rollers following reading of the card; a sensor for sensing displacement of a part of the card transport mechanism anywhere between the first pair of rollers and the second pair of rollers in a direction transverse to the path of the card; and a control circuit for ascertaining if the displacement of the part fulfills an alarm criterion indicative of both the card and a card trapping device being located on the path.