| 摘要 |
A document protection system is disclosed which employs a thermochromic pantograph and a validation mark. Also disclosed is a method to print thermochromic pantographs onto a substrate. A thermochromic pantograph according to the present invention has a latent image which is rendered visible when sufficient heat is applied to the document to activate the reactive properties of the thermochromic ink. The latent image could form a warning message such as "STOP" or "ALERT" which would alert recipients that a counterfeit copy has potentially been created. The thermochromic pantograph may also comprise a camouflage background pattern which conceals the printed ink of the latent image. A validation mark preferably has a latent "validation" image which can be visually identified on an original document, but which cannot be accurately reproduced by conventional copying or scanning means, and thus will not be visible on an unauthorized copy or duplicate. The use of both thermochromic pantograph and validation mark in the present invention provides multiple levels of protection against the unauthorized alteration or counterfeiting of valuable documents. Used in conjunction, these features allow the present invention to provide efficient and effective protection against unauthorized alterations and counterfeits. |
