| 摘要 |
PROBLEM TO BE SOLVED: To provide an information recording medium or the like in which even when written information is protected, the written information can be easily read.SOLUTION: In an information recording medium 1, an infrared fluorescence layer 13 including a phosphor excited by excitation light caused by infrared light and emitting the infrared light having a different peak wavelength from that of the excitation light is provided on a base material 11. The infrared fluorescence layer 13 includes a material absorbing an infrared absorption material 15 and enable writing by the infrared absorption material 15. In the information recording medium 1, the written information is covered with an infrared transmitting/visible light reflecting/absorbing layer 17, so that the written information is invisible and protected, meanwhile, irradiation with the excitation light caused by the infrared light enables the written information to be read even when the infrared transmitting/visible light reflecting/absorbing layer 17 is not removed. |
