Patent ID: 7557908

Claim:
An apparatus for determining the authenticity of a paper sheet to which such a substance that excites a light including a second wavelength longer than a first wavelength when irradiated with a light including the first wavelength is attached, the apparatus comprising: a light-emitting unit that emits the light including the first wavelength to the paper sheet; a first blocking unit that is arranged between the light-emitting unit and the paper sheet, and blocks off a light of a wavelength longer than the first wavelength; a light-receiving unit that receives a light including the second wavelength emitted from the paper sheet; a second blocking unit that is arranged between the light-receiving unit and the paper sheet, and blocks off a light of a wavelength shorter than the second wavelength; and an authenticity determining unit that determines the authenticity of the paper sheet based on the light received by the light-receiving unit.