| 摘要 |
A security card comprises an at least locally light-transmitting support and a signature-receiving spark- burning recording member 12 secured to it. The member 12 is made up of a paper base 14, a coloured light- transmitting lacquer 15 and a top coat of vacuum-deposited metal 16. Preferably the metal 16 is aluminium. A signature with a electrically-conductive pen connected to a current source and earthed through the metal 16 appears as a coloured image in reflected light where the metal has been removed by vaporisation. With transmitted light the signature appears as a lighter image than the surrounding metal 16. If the signature is surrounded, after its completion, by a continuous line where the metal 16 has been removed, earthing of the remaining metal adjacent the signature by a forger will be impeded. <IMAGE> |
