Abstract: A filament for use with identification cards to render them tamper and fraud resistant having a meltable core of twisted polymeric micro-filaments which is wrapped with metal foil in a manner to leave portions of the core exposed.

Abstract: Provided is an identification card having a photographic image support, the lower layer of which is impregnated with a hot-melt type thermoplastic adhesive, and a laminable indicia bearing layer and a durable resilient backing to which the support and bearing layer are laminated.

Abstract: An identification card includes a plurality of magnetizable spots, each spot comprising two portions of opposite polarity spaced apart by a distance d.sub.1. Adjacent spots are spaced apart such that the distance d.sub.2 between a pole on one spot and an oppositely magnetized pole on an adjacent spot is less than the distance d.sub.1. The direction of magnetization of each spot is determined by a corresponding horseshoe core magnetizing assembly. With the magnetizing assembly moved proximate to the corresponding spot, a current is passed in either of two directions through a coil wound about the horseshoe core, which action magnetizes a corresponding spot in either of two directions. A plurality p of the q spots represent binary inputs which are to be read. The remaining (q-p) spots are dummy spots which are not to be read and can be magnetized in any direction in order to confound a counterfeiter.

Abstract: An identification card, comprising several laminated layers, one of which is of material capable of being magnetized, has 350 spots on it, each of which is capable of having one portion of the spot magnetized north and the other portion magnetized south. The 350 spots are divided into groups of randomly selected spots. One group, for example, represents the serial number of the card and has the portions of its spots magnetized accordingly. Apparatus for reading, and for remagnetizing the card to change the information recorded thereon, is also provided. This apparatus includes a horseshoe core (for each spot) that bridges the two magnetized portions of the spot. A "Hall effect" device detects the direction of the flux in said horseshoe core to respond to the direction of the magnetism of the portions of the spot. The polarity of the portions comprising the spot may be reversed by energizing a coil on the horseshoe core.

Abstract: An identification card, comprising several laminated layers, one of which is of material capable of being magnetized, has 350 spots on it, each of which is capable of having one portion of the spot magnetized north and the other portion magnetized south. The 350 spots are divided into groups of randomly selected spots. One group, for example, represents the serial number of the card and has the portions of its spots magnetized accordingly. Apparatus for reading, and for remagnetizing the card to change the information recorded thereon, is also provided. This apparatus includes a horseshoe core (for each spot) that bridges the two magnetized portions of the spot. A "Hall effect" device detects the direction of the flux in said horseshoe core to respond to the direction of the magnetism of the portions of the spot. The polarity of the portions comprising the spot may be reversed by energizing a coil on the horseshoe core.