Patent ID: 7248730

Claim:
A method for discriminating the genuineness of a certified paper having at least one security mark including a non-electroluminescent ink and an electroluminescent ink that emits a light being exposed to an alternating current electromagnetic field and emits a fluorescent light being illuminated by a light having a specified wavelength, comprising the steps of: scanning a least a portion of the security mark; exposing a least a portion of the certified paper to a light source emitting the specified wavelength; detecting a first light emitted from the electroluminescent ink of the security mark at a light collecting spot with a first light detecting element configured to produce a first output value waveform corresponding to the intensity of light detected from the electroluminescent ink; detecting a reflected light from the electroluminescent ink of the security mark at a light collecting spot with a second light detecting element configured to produce a first output value waveform corresponding to the intensity of light detected from the non-electroluminescent ink; driving an alternating voltage applying means by an alternating voltage control means to produce an alternating current electromagnetic field; and discriminating the genuineness of the certified paper based on the first and second output value waveform of the fist and second light detecting elements, wherein the alternating voltage control means drives the alternating voltage control applying means only when the at least one of the first light detecting element and second light detecting elements detects the fluorescent from the electroluminescent ink.