| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve forgery, falsification and copy preventing effects of a valuable printed matter by combining a base material formed with many fine pores and an optical change element. SOLUTION: Many fine pores 1 are perforated at a base material 2 obtained by adhering a sheet 3 of an optical change element via an adhesive 4 by a laser beam. Specific information given to both surfaces of the sheet 3 can be confirmed not only at a front surface side of the material 2 but also at a rear surface side via the pores 1. If the information is given by perforating the pores 1 in a regular pore array, it can be optically read. Further, when the sheet 3 is intended to be released, the material 2 is broken caused by the many fine pores so that recovery of the array becomes difficult.</p> |
