Abstract

A bank note discriminating apparatus has a detector for detecting light reflected by or transmitted through a bank note upon irradiation of light while the bank note is being conveyed, and a judging circuit for integrating a reflected light signal from the detector to obtain an amount of light reflected by the bank note and for comparing the amount with a reference signal so as to discriminate a fit note from an unfit note. The apparatus further comprises a timing signal generator for generating printed and non-printed region signals in response to the transmitted light signal from the detector in accordance with the types of bank notes, an integrator circuit for calculating an output of the detector in accordance with the printed and non-printed region signals and calculating amounts of light transmitted through or reflected by a printed region and a non-printed region of each of the sheets, and a judging circuit for comparing the amounts of light reflected by or transmitted through the printed and plain regions with corresponding different reference signals, the amounts being generated from the integrator circuit, and for judging the sheets as clean or damaged sheets.