| 摘要 |
PROBLEM TO BE SOLVED: To provide an information recording medium etc., such that image information can be recorded to the medium later, and while image information is made invisible in a printed matter having the image information recorded to the medium, the image information is easily read with infrared light.SOLUTION: An information recording medium 1a is manufactured by forming a thermosensitive coloring layer 13 on a base 11, forming an infrared fluorescent layer 15 on the thermosensitive coloring layer 13, and further forming an infrared transmitting and visible light reflecting/absorbing layer 17 which transmits infrared light and reflects or absorbs visible light thereupon. Printed matter 10a is manufactured by recording image information 19 on the information recording medium 1a by heating the thermosensitive coloring layer 13 by a thermal head 21, so that a heated part color is developed. When the printed matter 10a is irradiated with infrared light as an exciting light, the infrared fluorescent layer 15 is excited to emit infrared light having a different peak wavelength from the exciting light. The infrared light is received and the image information 19 is read out of image data based upon a light reception quantity. |
