JPS647296A - Corrected paper money discriminator with transparent adhesive tape - Google Patents

Abstract

PURPOSE: To discriminate whether a certain paper money of which damage has been repaired with a transparent adhesive tape, or not by finding the ratio of output from a photodetector at the time of inserting and installing a polarizer in the preceding step of this photodetector in respect to the output of the photodetector at the time of neither inserting nor installing polarizer in the preceding step of the photodetector. CONSTITUTION: The ratio of output from a photodetector 6 at the time of inserting a polarizer 5 before the photodetector to the output of the photodetector 6 at the time of inserting no polarizer 5, at the time of reflection on the front face of a transparent adhesive tape 2 in the case of a repaired paper money 1, becomes the rate of polarizer vibration direction component in reflected polarization in respect to sully reflected polarization, but at the time of reflection on the surface of non-repaired paper money 1, this ratio becomes the rate of polarizer vibrating direction component in diffused reflected light in respect to fully diffused reflected light. Namely, the former ratio is extremely higher than the latter ratio. Therefore, the ratio found by a ratio operating part is compared with a prescribed value by a comparator part and when that ratio exceeds this prescribed value, based on it, the paper money is discriminated as a paper money repaired with a transparent adhesive tape.