| 摘要 |
PURPOSE:To provide a method wherein characteristics of retaining reliability of recorded information and properties of preventing falsification of recorded information are provided and necessary information can be surely recorded and read out by means of a recording mechanism and reading mechanism of relatively simple constructions whose appearances are good. CONSTITUTION:A synthetic resin layer 2 and a metallic reflection layer 3 are layered successively over one surface or both surfaces of a base material 1 and a square block region on the surface of the layer 3 is divided into four blocks to form it into a checkerboard-like shape, whereby the surface of the metallic reflection surface 3 of a region corresponding to one small block of the divided tour blocks selected based on a predetermined information signal to be recorded is formed into a surface having fine irregularities by means of a heating means to show a code mark. |
