| 摘要 |
PROBLEM TO BE SOLVED: To provide a secret information recording medium on which recorded information cannot be visually recognized under visible rays by can be selectively read by irradiation of ultraviolet rays. SOLUTION: Secret information requiring security is recorded in the secret information recording medium so that it can be concealed under visible rays. This medium is comprised of a support body 1, a first recording layer 2 which is formed on the whole or a part of the support body and reveals a light emitting or color developing property by irradiation of ultraviolet rays, and a second recording layer 3 which is formed on the first recording layer and consists of a photochromic material which has an achromatic transparent property under visible rays and is reversibly changed to an ultraviolet non-transmission property by irradiation of ultraviolet rays. |
