GB1081659A - Pattern or character recognition - Google Patents

Abstract

1,081,659. Verifying bank notes. AUTOMATIC CANTEEN COMPANY OF AMERICA. Dec. 15, 1964, No. 51109/64. Headings G4R and G4T. Apparatus for comparing one translucent object (e.g. a bank note) with another comprises a carriage adapted to move each object past a corresponding photo-electric sensing station so that each is scanned along a number of paths, the responses of the two sensing stations being compared to detect differences in the two objects. The apparatus is for dispensing goods in return for a bank note, the proffered bank note being compared with a standard, genuine bank note before being accepted. The standard bank note is carried in a recess 18, Fig. 1, in a sliding tray 12 and the customer places his bank note in recess 19. When button 39 is pressed motor 38 drives the tray so that the customer's bank note is carried under cover 31. During this movement both bank notes are illuminated by lamps 13, 14 and 15, 16 and a row 20 of photo-resistors senses the standard note, while a row 21 senses the customer's note. The resistances of the photoresistors change with changing amounts of transmitted light. Corresponding ones in the two rows are compared in a bridge circuit, Fig. 5b. Outputs are taken from variable potentiometers 101-111 connected between each pair of photo-resistors. The bridge is supplied by a centre-earthed transformer winding 112 and any difference in the resisance of a pair causes an output. These are combined in diodes 131-139 and applied to a transistor trigger circuit 120 which is set by a predetermined threshold signal to indicate that the proffered bank note does not compare with the standard. If the trigger 120 is not set the note is accepted and drawn into the machine by being forced through a central slot 44 in the tray, through a corresponding slot 45 in the housing and gripped by rollers which pass it to a bin. This is effected by a blade moving in guide 48 which moves downwardly under the control of solenoid 51 to fold the note through the slot. The trigger 120 is reset by the opening of a relay contact R2C at the beginning of this operation and is set again by signals from photo-resistor pairs 94, 94<SP>1</SP> and 95, 95<SP>1</SP> placed on either side of the slot. These give a setting signal when the bank note has been fully removed from the tray and direct light falls on photo-resistors 94<SP>1</SP> and 95<SP>1</SP>. The dispensing mechanism is now operated to deliver the good purchased at 11. To compensate for differences in the general light transmitting properties of the two bank notes, the amount of light transmitted by each is sensed and the lamp 13 is controlled to be more or less bright than lamp 15, and lamp 14 is similarly varied with respect to lamp 16.