| 摘要 |
<p>PROBLEM TO BE SOLVED: To enhance a forgery prevention function by invisible and visible latent image patterns when copied by a copying machine. SOLUTION: In image streak patterns comprising one or a plurality of straight or curved lines, image streaks 6 given no latent images are formed of full lines, and streaks 7, 8 given latent images are formed of fixed cycle broken lines comprising image streaks being plurality divided at equal distances in reference of a standard streak direction and configured in which plurally divided streaks are arranged at constant distances, and thus the image streaks 7 given latent images lead to invisibility by allowing a total of an image streak area in a part equal to one cycle comprising the image streak parts and non- image streak parts being plurally divided in the standard streak direction to be equal to an image streak area in the part equivalent to the same length as one cycle comprising image streak parts and non-image streak parts being plurally divided in the standard streak direction; similarly, the image streak lines 8 lead to visibility by being made larger than an image streak area of the part equivalent to the same length as one cycle.</p> |
