| abstract |
(57) Abstract: To use an ink having different physical characteristics (light characteristics) even in a limited printing range, so that a large amount of information can be added and read. Moreover, the recognition rate of the printed matter and the security are improved. SOLUTION: Excitation light characteristic (wavelength) and emission light characteristic (wavelength) By using a plurality of types of different inks and combining these inks, the information is individually extracted. Since a large amount of information can be printed in a limited printing area and incident light and reflected light can be separated, a signal with a high S / N ratio can be read. |