| 摘要 |
PURPOSE:To attain a magnetic card which is prevented from forgery, by laminating a layer in order which includes a pattern consisting of thin films of a metal (oxide), and a layer including glass beads, on a face in the side opposite to a magnetic recording face of a magnetic card to provide a retroreflective plate. CONSTITUTION:A transparent resin layer 8 is formed with a thickness of 0.05- 0.1mm. on a polyester film 9 by printing or applying, and a layer 6 where glass beads 6 having a size of 20-88mu are arranged in one line is formd on the surface of the layer 8. A transparent resin layer 7 similar to the layer 8 is formed on the layer 6 to cover glass beads. A pattern layer 4 consisting of an In2O3 and an SnO2 is vapor-deposited with a thickness of 50-500Angstrom on the layer 7 or a thin film pattern 4 consisting of gold, Al, or the like is formed on the layer 7. Next, a tansparent resin layer 5 covering this pattern 4 is formed. A magnetic recording layer 2 and a printed protection layer 3 are formed in order on a hard plastic sheet 1, and this plastic sheet 1 and the layer 5 are joined to produce a magnetic card. The pattern 4 is too thin to be discriminated with the naked eye. such thickness is given to the pattern 4 that the reflected light is taken out as an electric signal to recognize the pattern 4 in an electrooptic device, thereby preventing forgery. |
