Apparatus and method of determining conditions of bank notes

摘要

An apparatus and method for providing an indication of a type and/or a condition of a note passing through the apparatus includes a note transport (12) which moves the note past transversely spaced spot sensing assemblies (18). Each spot sensing assembly includes four emitters (32). Each of the emitters produces radiation at different wavelengths. The spot sensing assemblies include a reflectance detector (20) and a transmission detector (22) which are disposed on opposed sides of the passing note. The emitters direct radiation onto test spots (34) on the passing note. Radiation reflected from and transmitted through the test spots is detected by the respective reflector and transmission detectors. A control circuit (24) produces sensed values that correspond to the detected radiation. A data store in operative connection with the control circuit comprises memories (138) that include stored data representative of transition and reflectance values for know note types. The control circuit calculates a level of correlation between the stored values and the sensed values. By comparing the correlated values to threshold values, the control circuit is operative to determine the type of note and other conditions such as if a note is worn, soiled, or a doubles note.