METHOD FOR ENCODING OF INVISIBLE INK AND SECURITY DOCUMENT ADAPTING THE SAME

摘要

PURPOSE: A coding method of invisible inks and security prints applying the same are provided to show different wavelength patterns according to the irradiated wavelength of the light by arranging the inks which absorbs the different invisible wavelength regions. CONSTITUTION: A coding method of invisible inks comprises the following steps: displaying different wavelength patterns according to the irradiated wavelength of the light; arranging the inks which absorb the different invisible wavelength regions; selecting the ink from ranges of 830 to 850 nano meters, 900 to 980 nano meters, 1020 to 1060 nano meters; and analyzing the corresponding code by checking the fact that the absorption wavelength pattern of the arranged ink is changed according to the wavelength of the irradiated light. The ink includes the phthalocyanine based near infrared ray absorption materials. The ink has the identical apparent color as the printed part of the security prints. The light within the wavelength range of the coded ink is irradiated.