| 摘要 |
<p>PURPOSE:To provide a diffraction pattern recording medium, which can be authenticated by a card processing device having an optically reading means and is hardly forged and falsified, and a method of authenticating the medium. CONSTITUTION:A diffraction pattern recording medium comprises: a relief layer 3 consisting of a resin layer 1, on which a diffraction pattern is recorded as a recess and protrusion pattern, and a thin film layer 2, which is formed on the surface of the resin layer 1 having thereon the recess and protrusion pattern, has refractive index different from that of the resin layer 1 and is capable of transmitting visible rays and infrared rays; a concealing layer 4, which substantially transmits the infrared rays and does not transmit the visible rays; and an infrared ray absorbing part 6 or a printed part consisting of a reflecting part, each being laminated on one another in order. Authentication of the medium is done by a method of certifying the infrared rays through the relief layer 3 and the concealing layer 4, reflecting the infrared rays from the printed part, detecting the rays reflected again through the concealing layer 4 and the relief layer 3 with an infrared ray detecting device, and reading the pattern such as a symbol, a letter, a code, etc., recorded on the printed part 8, whereby the diffraction pattern recording medium is identified.</p> |
