FIELD: printing.
SUBSTANCE: group of inventions relates to means of authentication of documents. In the method, the irradiation with the excitation light is carried out, the first module of light receiving receives light having a first wavelength range, that comprises the peak wavelength of fluorescence, excited in the fluorescent substance, as a result of irradiation by the excitation light, and the second module of light receiving receives light emitted from the same area as the area of the sheet of paper, which emits light received by the first module of receiving light, the said light has the second wavelength range, which is located next to the first wavelength range. Then the module of determining the fluorescent substance determines type of the fluorescent substance added to the sheet of paper based on the outputs from the first module of receiving light and the second module of receiving light, and the assessment module assesses whether the sheet of paper is genuine or counterfeit, based on the result of assessment of the module of determining the fluorescent substance.
EFFECT: technical result is to improve the detection accuracy of authenticity.
13 cl, 21 dwg
