| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a medium having an image changing function not increased in cost in the formation of a latent image such as a concealed character or the like of which the duplication due to a color copier is difficult, requiring a special device or the like in the development of an image, capable of being repeatedly used and excellent in heat resistance and light fastness. <P>SOLUTION: Upper and back surface numerous-line patterns 20 and 30 having the same shape are printed on the upper and back surfaces of a transparent plastic sheet 10 in a registered state. The upper surface numerous-line pattern 20 becomes a latent image part and a non-latent image part while the back surface numerous-line pattern 30 only becomes the non-latent image pattern. The latent image part becomes the medium (card 1) having an image change function formed within the range of 1/4-2/3 pitch with respect to numerous lines forming the non-latent image part, preferably formed on numerous lines shifted by a 1/2 pitch. <P>COPYRIGHT: (C)2004,JPO</p> |
