Fault detecting devices for character recognition

Claim 1

A CIRCUIT ARRANGEMENT FOR ANALYSING A DOCUMENT IN MOVEMENT BEARING CODED CHARACTERS WHICH ARE EACH COMPOSED OF A FIXED NUMBER OF SEPARATE VERTICAL STROKES, SAID ARRANGEMENT COMPRISING IN COMBINATION: FIRST MEANS FOR SEQUENTIALLY GENERATING A PULSE DERIVED FROM THE REAR EDGE OF EACH OF THE READ STROKES, FIRST TIME MEASURING MEANS FOR DISCRIMINATING THE TIME INTERVALS BETWEEN THESE PULSES, A FIRST BISTABLE FLIP-FLOP CONNECTED FOR STORING ACCORDING TO THIS DISCRIMINATION, AMONG THE INTERVALS CORRESPONDING TO A CHARACTER, THOSE INTERVALS WHICH ARE LONGER THAN A PREDETERMINED TIME PERIOD, A FAULT DETECTING ARRANGEMENT INCLUDING SECOND MEANS FOR SEQUENTIALLY GENERATING A PULSE DERIVED FROM THE LEADING EDGE OF EACH OF THE READ STROKES, SECOND TIME MEASURING MEANS FOR DISCRIMINATING THE TIME INTERVALS BETWEEN THE LATTER PULSE''S A SECOND BISTABLE FLIP-FLOP CONNECTED TO SAID SECOND TIME MEASURING MEANS FOR STORING ACCORDING TO THIS DISCRIMINATION THE TIME INTERVALS LONGER THAN SAID PREDETERMINED TIME PERIOD, AND COMPARING LOGICAL CIRCUITS COUPLED TO SAID FIRST BISTABLE FLIP-FLOP AND TO SAID SECOND BISTABLE FLIPFLOP AND ADPATED FOR GENERATING AN ERROR SIGNAL UPON OCCURRENCE OF AN ABNORMAL TIME SHIFT BETWEEN THE STORED INTERVALS REPRESENTATIONS ISSUED RESPECTIVELY FROM THE REAR AND LEADING EDGES OF THE CHARACTER STROKES.