MAGNETIC SECURITY DOCUMENT AND METHOD FOR MAKING SAME

摘要

A security document having a magnetic recording layer containing uniformly dispersed magnetizable material having magnetic anisotropy wherein the material at a plurality of selected locations is differently physically aligned with respect to a reference location to provide a magnetically detectable permanent fixed information pattern such as a code pattern useful for authenticating the document. The document is authenticated in the following manner. A magnetic field is applied to the document to cause the material within the plurality of selected locations to be differently magnetized according to the physical alignment thereof. The differently magnetized selected locations are subsequently sensed by traversing the document past a sensor device to provide a signal representative of the plurality of selected locations. This signal is compared with a predetermined signal pattern to authenticate the document.