| 摘要 |
A composite identity marking comprising first and second identity markings is provided on a substrate ( 1 ) of a security document. The first identity marking is provided by a first marking station ( 5, 5', 5'', 5 ''') by bringing a first side of said substrate ( 1 ) into marking relationship with said first marking station ( 5, 5', 5'', 5''' ). The second identity marking is provided by a second marking station on a portion of the second side of said substrate ( 1 ) provided with a layer of material ( 60 ) capable of absorbing a substantial amount of radiation emitted by a laser beam. Said laser beam is produced by a laser marking station ( 6, 6 ') included in said second marking station and directed onto said layer of absorbing material ( 60 ) through the first side of the substrate and across said substrate to form said second identity marking only on said second side of the substrate ( 1 ). |
