Development of optically variable devices for document security

摘要

Document counterfeiting has become a significant source of revenue loss in many industries,particularly in the banking and retail sectors.In addition to the direct economic losses in banknotes and financial transaction documents(estimated at ~10-15 billion each year in the USA),the counterfeiting of visas,passports,ID cards and other official security documents has implications for national security.The ability to produce counterfeit documents of high quality has become widespread due to the availability of digital scanners and high resolution colour copiers.This equipment has reduced the effectiveness of traditional security features such as intaglio printing and complex design patterns in protecting the integrity of high security documents.