FRAUDPROOF PAPER, FRAUDPROOF PRINTED MATTER AND DETECTION OF FRAUDPROOFING MEANS

摘要

PROBLEM TO BE SOLVED: To provide a means for automatically detecting a fraudproofing means by using a thread-inserted windowed paper having a thread exposed in windows opened on the surface of a paper leaving spaces between the windows. SOLUTION: The objective fraudproof paper is provided with windows W and tunnels 1 continuously formed on the surface of a paper in the flowing direction of the paper. The lengths of the windows and/or tunnels are different in the flowing direction of the paper and a thread T having an optical property different from that of the tunnel is exposed in the windows. A prescribed print is applied to the surface of the fraudproof paper to obtain a fraudproof printed matter. The paper can be identified by automatically detecting the length of the thread exposed in the fraudproof paper or in the window of the fraudproof paper and the length of the tunnel by an optical means.