ES347372A1 - Systems for the automatic reading of information - Google Patents

Abstract

In a system for automatically reading information carried by moving objects or vehicles, e.g. a rail vehicle, the vehicle carries a plate perforated in accordance with the information which is scanned in passing by light, X-ray or gamma-ray radiation from a traokside source and the radiation transmitted by the plate energizes detectors also disposed adjacent the track. One example of plate is shown in Fig. 8 and includes an upper row 52 perforated in accordance with the information, a lower row 84 perforated in accordance with its complement and a middle row 83 regularly perforated to provide synchronizing and reference signals. The information is coded in decimal binary form and the left and right hand sides of the plate GAU and DRO are perforated to provide start and finish signals or vice-versa depending on the direction of movement of the plate. Four detectors are provided, sync. detector 1 and reference detector 2 co-operate with the middle row and information detectors 3 and 4 co-operate respectively with the upper and lower rows. Detector 1 is associated with a signal generator 5 which supplies a positive signal DS at terminal 18 when the detector is illuminated and a similar signal DS at terminal 19 when the detector is not illuminated, similarly detectors 2-4 provide signals DR, DR D1, D1 and D2, D2 at terminals 20-25. The reference and information signals are applied with signals T+ and T-, representing transitions in the sync. signal DS, to a start and finish correlator 10 which supplies start D + or D- and finish F+ or F- signals (+ or - depending on the direction of motion) to a programmer 12 which supplies a read signal L to synchronization member 9 and information correlator 11. The sync. member 9 supplies pulses S+ or S-, derived from transitions in signals DR and + or - in dependence on the direction of movement, to a reversible counter 13 having a capacity N equal to the number of binary digits. The. counter .via a matrix 14 and address member 15 prepares in turn the N elements of a memory 16 to receive the information signals Io (binary 0) and I1 (binary 1) from information correlator 11 in which the information signals are sampled by pulse train T . The information read into the memory 'is transferred to a register 17 from which it is transferred to a utilization device on receipt of finish signal TR from programmer 12. The reversible counter allows the plate to be read in either direction and also allows the plate to be read should the vehicle stop, reverse, then restart in the original direction during the reading process. Error signals delivered respectively by the information correlator 11 (EC), the memory 16 (EM) and the programmer 12 (EP) are connected to OR gate 18 which supplies an output to return the counter, the memory and the programmer to zero.