| 摘要 |
PROBLEM TO BE SOLVED: To improve security more than in the conventional and further to remarkably increase an information quantity recordable in the same printing area concerning a printed matter, having an invisible print part such as a stealth bar code and reading techniques therefor. SOLUTION: An invisible printing part using the fluorescent object of different afterglow time is overlapped and printed on a substrate and by detecting/ processing the light emitting output and afterglow output, two kinds of invisible print parts can be read separately. Thus, the invisible information, such as bar code for the double information quantity can be printed and recorded in the same printing area and the printed matter having high security, and reading techniques therefor can be provided. |
