Patent ID: 6094500
Filing Date: 2000-07-25
Classification: G07D

Abstract:
An apparatus for authenticating a sheet, the apparatus comprising:a light source for irradiating the sheet with ultra violet light;a first sensing unit for (i) sensing fluorescence of the sheet when irradiated with ultra violet light, and (ii) generating a signal indicative of the fluorescence of the sheet when irradiated with ultra violet light;a detection unit for generating a signal indicative of authenticity of the sheet based upon the signal of the first sensor unit, and said detection unit (i) determines when the signal of the first sensing unit attains a predetermined threshold value, and (ii) generates the signal indicative of the authenticity of the sheet when the signal of the first sensing unit attains the predetermined threshold value; anda second sensing unit for (i) monitoring ultra violet light level of the light source, and (ii) generating a signal used as the predetermined threshold value based upon the ultra violet light level of the light source.