| 摘要 |
PURPOSE:To prevent identification information from easily being reproduced and to preclude forging by recording fake identification information and real identification information on an optical recording medium repeatedly as a diffraction pattern. CONSTITUTION:The fake identification information and real identification information are stored repeatedly on the optical recording medium as the diffraction pattern. Then interference fringes formed with recording light and reference light are recorded on a photosensitive plate 9 and when the photosensitive plate 9 is irradiated with the laser light outputted by a laser oscillator 1 through a lens 10, the light is diffracted by the diffraction pattern recorded on the photosensitive plate 9 as the interference fringes to reproduce a stereoscopic image of a bar code pattern recorded as a repro duced image. When this is viewed in one direction of the diffraction, a bar code image 7' which is the real identification information can be reproduced and a virtual image of a bar code pattern 8 which is the fake identification information is eliminated. Consequently, the recording medium is hardly forged, so an accident due to the forging is precluded. |
