To improve the reliability of a detection of foreign matter when detecting tokens passing through a route.

When pulsed light emitting signals are output to a first light emitting part 216a and a second light emitting part 216b, the properties of the pulse signals are changed. For example, the pulse signals are so output to change the pulse amplitude or the pulse width. The first light receiving part 220a and the second light receiving part 220b receive the light simultaneously with the light emission signals of the pulse properties and output light receiving signals according to the light quantity determined by the pulse amplitude/pulse width. A self-luminous foreign matter executes pulsed light emission, however, its light emission has no pulse properties described in the above, so that this method can highly reliably detect the light emitting foreign matter based on the change state of the pulse signals for the light emission and output state of the light receiving signals.

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