| 摘要 |
PURPOSE:To expand the display area of visual information and to effectively prevent the visual information from being forged and altered by sticking an optical reading medium to a substrate so as to cover a part of a visual pattern on the substrate. CONSTITUTION:The optical reading medium 3 is sticked to one side of the substrate 2 on which a visual pattern 10 consisting of characters or the like is formed. An optical reflection layer 5 on which a dot-like data bit 6 or a groove-like guide track is formed is evaporated on a transparent substrate 4 to form the medium 3 and the layer 5 is constituted so as to cover a part of a pattern layer 10. A laser beam is radiated and the contents of a bit 6, track or the pattern layer 10 are observed, but since the size and pitch of the bit 6 are small, the layer 10 can be observed through the layer 5. Thereby, the display area of the visual information can be expanded and the information can be prevented from being forged and altered. |
