Conductive security article with detector apparatus

摘要

A security system includes a security article and a corresponding detector. The security article comprises a substrate layer having a top surface and a bottom surface. The substrate layer is composed of an electrically nonconductive material. Deposited on the top surface of the substrate layer is a conductive thin film coating having a predetermined electrical resistance between two spaced apart points. In one embodiment, the conductive thin film coating is comprised of a transparent conductive compound and has a thickness in a range between about 7 nanometers to about 700 nanometers. Printing can be positioned either on top of the substrate layer or on top of the thin film coating. The detector corresponds to the security article and has a light source and a pair of spaced apart probes. The detector contains electrical circuitry configured to energize the light source when an electrical resistance is produced between the probes that corresponds to the predetermined electrical resistance for the security article.