Apparatus for checking banknotes

摘要

The invention relates to an apparatus for checking bank notes which scans the bank notes to be checked by means of a semiconductor array. The inventive apparatus for checking bank notes has two linear semiconductor arrays formed of at least three layers which are sensitive to light of different wavelengths, a first linear semiconductor array scanning the bank notes in a defined range of spectral sensitivity of the semiconductor (e.g. in the visible range), and a second linear semiconductor array scanning the bank notes in a range different therefrom (e.g. of invisible infrared light). From the signals of the two arrays a color image of the bank note and at least one image in the range of invisible light are obtained by suitable combination. The inventive apparatus has the advantage that it can be realized simply and economically, and provides good check results since it avoids artifacts which can be caused for example by parallactic errors.