-
公开(公告)号：EP1436774A1
公开(公告)日：2004-07-14
申请号：EP02781215.5
申请日：2002-10-04
CPC分类号： B41M3/14 , B41M5/40 , B42D25/29 , D21H21/48 , G06K19/06028 , G06K2019/06225
摘要： The invention relates to a valuable document, a security element and a security mark, which contain a marking substance that is absorbent in the infra-red spectral range between 1000 and 2500 nm, but is not significantly absorbent in either the visible spectral range, or at 800 nm. Said marking substance cannot therefore be recognised by the widespread simple IR reading devices, which operate at approximately 800 nm. Preferably, an additional overprint is added, which is absorbent in the visible spectral range and also at approximately 800 nm, but not in the 1000 to 2500 nm range. According to the inventive method, for verification the marked location is irradiated with infra-red light in the 1000 to 2500 nm range and the absorption is determined.
搜索结果
1 条记录 (耗时 0.011 秒)
筛选
AND
AND
过滤
NOT
NOT
扫码加群
