PURPOSE: To simply discriminate forgery by making a card hard to forge, by reading kind discrimination data optically by utilizing the difference of reflectivity between the wavelengths of two or more places.
CONSTITUTION: Data for confirming the kind of a card is printed on the surface of a substrate 10 and contains first data pattern 14 for preventing forgery and the second data pattern 16 of dummy data. A discrimination data reading apparatus is constituted so that the first data pattern 14 printed by special ink is irradiated with light or laser containing a specific wavelength and only the reflected light having specific wavelength is detected to read discrimination data. The first data pattern 14 is irradiated with light having a wavelength of 650nm or more in the wavelength region of the reflecting spectrum of the special ink and light having the wavelength within the wavelength region of the absorption spectrum of the special ink and the intensities of the reflected lights are measured at every wavelengths to read the difference between the intensities of lights. When the difference between the intensities of the reflected lights at two places does not exceed a definite threshold value, a forged card is discriminated.
SUZUKI MANABU
WATANABE JIRO
| JPS58171995A | 1983-10-08 | |||
| JPS5845999A | 1983-03-17 |
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