| 摘要 |
<p>PURPOSE:To substantially invalidate malicious copying by a method wherein, in a printed matter on which at least two patterns based on a plurality of constitution elements are printed, adjacent intervals of the respective constitution elements of the patterns are made different for each of the patterns and the size of the constitution elements in the patterns is changed stepwise within the patterns. CONSTITUTION:As a copy restraining pattern of a printed matter 2, two patterns of a background 4 constituted of dots having a narrow halftone pitch and a rectangular figure 6 constituted of dots having a wide halftone pitch are used, and the size of the dots, or the thickness of numerous lines, constituting the patterns are changed slantingly or stepwise. Furthermore, alignment at adjacent portions of the background 4 and the rectangular figure 6 is performed, whereby the background 4 and the rectangular figure 6 are made hardly distinguishable by visual observation. If this printed matter is copied by a copying apparatus, a copied portion of the background 4 and a copied portion of the rectangular figure 6 appear clearly, and a copy is easily found out.</p> |
