Coin recognition apparatus and coin recognition method

A coin recognition apparatus that performs recognition of a coin, being transported, by using a magnetic sensor that detects a signal induced in a receiving coil due to a magnetic field produced by passing a current through an oscillator coil, the coin recognition apparatus comprising:

• a synthesized signal applying unit that applies to the oscillator coil a synthesized signal containing signals of a plurality of designated frequencies;
• an expansion unit that converts an output signal, which is a signal output from the receiving coil when the synthesized signal is applied to the oscillator coil by the synthesized signal applying unit, into a digital signal and expands the digital signal on a frequency axis;
• a coin recognition unit that performs recognition of the coin based on amplitudes of the signals of the designated frequencies extracted from the signals expanded by the expansion unit;
• and
• a coin center detecting unit that detects whether a coin center, which represents a substantially central line on a surface of the coin, has reached the magnetic sensor based on the output signal output from the receiving coil when a single-frequency signal is applied to the oscillator coil,
• wherein the synthesized signal applying unit applies the synthesized signal to the oscillator coil when the coin center is detected by the coin center detecting unit.