Card reader and control method therefor

A card reader for use with a card in which an IC chip is provided, and in which an external connection terminal of the IC chip and a magnetic stripe are formed, the card reader comprising:

• a card insertion slot into which the card is inserted;
• a metal detecting mechanism structured to detect the external connection terminal of the card inserted into the card insertion slot;
• a jamming magnetic field generation mechanism structured to generate a magnetic field for prevention of fraudulently reading a magnetic datum recorded in the magnetic stripe;
• and
• a control unit of the card reader;
• wherein the metal detecting mechanism comprises an exciting coil and a detecting coil;
• the jamming magnetic field generation mechanism comprises a jamming magnetic field generating coil;
• and
• the control unit is structured to alternately switch between a current supply to the exciting coil and a current supply to the jamming magnetic field generation coil, and detect the external connection terminal on the basis of an output from the detecting coil at a time when the exciting coil is supplied with a current.