Bi-directional digitizer

Claim 1

A FREQUENCY DIFFERENCE DIGITIZER FOR DIGITIZING THE FREQUENCY DIFFERENCE BETWEEN A REFERENCE SIGNAL AND A DATA SIGNAL, SAID DIGITIZER COMPRISING (A) MEANS RESPONSIVE TO SAID REFERENCE SIGNAL FOR PROVIDING A PLURALITY OF REFERENCE PULSES DISPLACED IN PHASE FROM ONE ANOTHER DURING EACH CYCLE OF SAID REFERENCE SIGNAL, (B) MEANS RESPONSIVE TO SAID DATA SIGNAL FOR PROVIDING PULSES IN EACH CYCLE THEREOF WHICH HAVE DURATIONS ABOUT EQUAL TO THE INTERVAL BETWEEN SUCCESSIVE ONES OF SAID REFERENCE PULSES, (C) COMPARING MEANS RESPONSIVE TO SAID DATA PULSES AND SAID REFERENCE PULSES AND INCLUDING (I) A PLURALITY OF FLIP-FLOPS, (II) MEANS FOR APPLYING DATA PULSES TO SAID FLIPFLOPS FOR ENABLING THEM TO BE CONDITIONED INTO AT LEAST ONE OF SAID STATES. (III) MEANS FOR APPLYING SAID REFERENCE PULSES TO SAID FLIP-FLOPS FOR CONDITIONING THEM INTO AT LEAST SAID ONE STATE AND, (IV) A PLURALITY OF GATE CIRCUITS EACH ADAPTED TO BE ENABLED AND TRIGGERED RESPECTIVELY BY DIFFERENT ONES OF SAID FLIP-FLOPS TO PRODUCE AN OUTPUT, AND (D) FIRST AND SECOND OUTPUT LINES COUPLED TO DIFFERENT ONES OF SAID GATE CIRCUITS WHEREBY SAID FIRST OUTPUT LINE CARRIES PULSES REPRESENTING A REFERENCE SIGNAL FREQUENCY HIGHER THAN SAID DATA SIGNAL FREQUENCY AND SAID SECOND OUTPUT LINE CARRIES PULSES REPRESENTING A REFERENCE SIGNAL FREQUENCY LOWER THAN SAID DATA SIGNAL FREQUENCY.