GB1030780A - Improvements in or relating to sequence-recognising apparatus - Google Patents

Abstract

1,030,780. Character recognition. STANDARD TELEPHONES & CABLES Ltd. Nov. 27, 1964, No. 48244/64. Heading G4R. A predetermined sequence of events is detected in a succession of events defined by signals on lines A-E (Fig. 1, not shown) by gates 14 responding to the occurrence of a pair of events in a given order and each gate output 15 is selectively transmitted through a pre-set switch 18 to a sequence-responsive output 11. Each signal 10 is stored in a register 16 and shifted to the central position by a delay D and subsequently shifted to an output line 13 by the arrival of the next input 10 operating the delay D. Switches 18. (Fig. 2, not shown) may be set by applying a set signal 19 during a learning phase to open those switches operated by AND gates 14. In order to detect sequences of groups of signals applied in predetermined time intervals, the inputs 10 are stored in flipflops (Fig. 3, not shown) during the time interval determined by a mono-stable device prior to transfer to further flip-flops in the lines 13 for comparison with the next timed group of inputs 10. The AND gates 14 may be such as to produce a light pulse when activated to operate photo-sensitive switches 18. The apparatus may be pneumatic or hydraulic.