Digital pulse generator with compensation for document velocity variations

Claim 1

IN A DOCUMENT READING MACHINE, THE COMBINATION COMPRISING: A FIRST DOCUMENT DETECTOR POSITIONED AT A PREDETERMINED DISTANCE DOWNSTREAM OF THE READ STATION IN THE DOCUMENT PATH OF SAID DOCUMENT READING MACHINE AND OPERABLE TO GENERATE SIGNAL UPON DETECTING THE PRESENCE OF A DOCUMENT, A SECOND DOCUMENT DETECTOR POSITIONED AT A PREDETERMINED DISTANCE UPSTREAM OF THE READ STATION AND OPERABLE TO GENERATE A SIGNAL UPON DETECTING THE PRESENCE OF A DOCUMENT, LOGIC CIRCUIT MEANS CONNECTED TO SAID FIRST AND SECOND DOCUMENT DETECTORS AND OPERABLE TO GENERATE AN OUTPUT SIGNAL ONLY WHEN SAID FIRST DOCUMENT DETECTOR ALONE IS DETECTING THE PRESENCE OF A DOCUMENT, AN OSCILLATOR, A FIRST COUNTER CONNECTED TO SAID OSCILLATOR TO BE ADVANCED THEREBY, A FREQUENCY DIVIDER CIRCUIT CONNECTED TO SAID LOGIC CIRCUIT MEANS TO BE RENDERED OPERABLE THEREBY, AND CONNECTED TO SAID FIRST COUNTER TO PROVIDE AN OUTPUT SIGNAL EVERY TIME SAID FIRST COUNTER REACHES A PREDETERMINED VALUE, THE OUTPUT OF SAID FREQUENCY DIVIDER CIRCUIT BEING CONNECTED TO SAID FIRST COUNTER TO RESET THE SAME WITH SAID OUTPUT SIGNAL, A SECOND COUNTER CONNECTED TO SAID LOGIC CIRCUIT MEANS TO BE RENDERED OPERABLE THEREBY AND CONNECTED TO SAID FREQUENCY DIVIDER CIRCUIT TO BE ADVANCED BY THE OUTPUT SIGNAL THEREFROM, COMPARING MEANS CONNECTED TO SAID SECOND DOCUMENT DETECTOR TO BE RENDERED OPERABLE DURING THE PERIOD A SIGNAL IS GENERATED BY SAID SECOND DOCUMENT DETECTOR AND CONNECTED TO SAID FIRST AND SECOND COUNTERS TO GENERATE AN OUTPUT SIGNAL UPON THE VALUES IN SAID COUNTERS BEING EQUAL, THE OUTPUT OF SAID COMPARING MEANS BEING CONNECTED TO SAID FIRST COUNTER TO RESET THE SAME TO ENABLE SUCCESSIVE COMPARISONS TO BE MADE BETWEEN SAID FIRST AND SECOND COUNTERS.