| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a document with a discernible image, if the resolving degree of a color copying machine is increased. SOLUTION: In this document 1 consisting of a concealed character 3 revisualized by a color copying machine and a background part 2 which makes the concealed character 3 undiscernible, printed on the paper face, either of the concealed character 3 or the background part 2 printed in phthalocyanine green pigment and the other is printed in green pigment. If the character 3 is reproduced, the phthalocyanine green pigment is visualized in blue, while the green pigment is visualized as it is in green. Consequently, both character 3 and background part 2 of the original document 1 appear green and therefore, the concealed character 3 cannot be visually identified. However, the copy 10 of the original document 1 visibly shows the concealed character 13, the fact of which reveals the clear identity of the copy 10.</p> |
