Document recognition apparatus

摘要

Document recognition apparatus for banknotes (1) utilises bar codes which are printed in fluorescent ink on the face of banknotes (1). The bar codes are read by transporting the notes past a reading station (4) where an ultra-violet lamp (5) illuminates the notes (1) and causes any barcoded information printed on them to fluoresce and be detected by a photodiode (9) sensitive to the wavelength of the fluorescence. To ensure that the barcode is read irrespective of which way up a note is transported, and irrespective of which edge of the note leads, additional reading stations may be provided. To help read old and dirty notes, as well as to detect forgeries, the output of the photodiode may be fed to a neural network.