PURPOSE: To prevent the forgery of the paper moneys, the securities, etc., by deciding whether or not the detected color image information is coincident with the color image of a specific color that is previously set or the registered color image of a specific pattern that is previously registered.
CONSTITUTION: The R, G and B signals of a color copy are read by a CDD sensor 303 of a color copy detecting part 801 and amplified by an amplifier 802. These amplified signals are converted into the digital signal by an A/D converter 803. Then a deciding part 804 decides whether the digital R, G and B signals are identical with a specific color (e.g. a paper money) set previously or not. Then the specific color set previously is decided at the part 804, and a comparator and the AND circuits 806 and 807 decide whether the specific color is kept or not in the ranges RL-RH, GL-GH and BL-BH which are previously set in response to the R, G and B signals respectively to output an H signal.
TAKAHASHI HIROSHI
KANEKO YOSHIO
