| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide media with a high forgery preventing effect which are extremely hardly prepared and duplicated except by a regular media issuer on various media repeatedly used, and a forgery preventing method using this. <P>SOLUTION: At least one layer of a truth discriminating layer 20 comprising at least a thermal color developing composition and a photo-thermal converting material and whose color tone is reversibly changed by heating or irradiating it with a light with a specified wave length, is formed on the face of a substrate 1. The truth discriminating layer 20 is characterized by forming it by selecting an arbitrary thermal color developing composition among a plurality of kinds of the thermal color developing compositions, and performing the truth discrimination in accordance with the color tone of the color development. <P>COPYRIGHT: (C)2004,JPO&NCIPI |
