| 摘要 |
A security document that is not faithfully replicable by scanning-type copying devices having scanning lines (36) with a defined pitch distance (p) and width the document having an area comprising a visible printed image (10, 40) of art, pictures and/or image forms with curvilinear lines, dots and/or swirls, the visible printed image containing a grid pattern of printed and/or unprinted parallel lines (32) in which the differences between the pitch distance (d) of the parallel lines and the scanning pitch distance (p) is within a range, plus or minus, from about one-half the width of the scanning lines to about one-half the pitch of the scanning lines, the grid pattern causing visibly discernable interference (e.g., moire) patterns and/or false tones, colors or omissions in the image in copies of the document made by the copying devices. <IMAGE> |
