Television magnetic tape reproducing system

Claim 1

IN A TELEVISION MAGNETIC TAPE REPRODUCING SYSTEM FOR USE WITH A TELEVISION RECEIVER INCLUDING SWITCHING MEANS BY WHICH A TELEVISION SIGNAL RECEIVED OVER A COMMUNICATION PATH CAN BE DISPLAYED BY SAID RECEIVER, A DEVICE FOR REPRODUCING A TELEVISION SIGNAL INCLUDING VERTICAL AND HORIZONTAL SYNCHRONIZING PULSES FROM SAID MAGNETIC TAPE, SAID SYNCHRONIZING PULSES BEING SUBJECT TO VARIATIONS IN FREQUENCY INTRODUCED DURING THE SIGNAL REPRODUCING OPERATION, MEANS TO APPLY SAID REPRODUCED TELEVISION SIGNAL FROM SAID DEVICE TO SAID SWITCHING MEANS IN SAID RECEIVER, MEANS FOR SEPARATING SAID VERTICAL AND HORIZONTAL SYNCHRONIZING PULSES FROM SAID REPRODUCED TELEVISION SIGNAL AND FOR FEEDING SAID VERTICAL SYNCHRONIZING PULSES TO SAID SWITCHING MEANS, A SYNCHRONIZING UNIT, MEANS TO APPLY SAID HORIZONTAL SYNCHRONIZING PULSES FROM SAID SEPARATING MEANS TO SAID SYNCHRONIZING UNIT, SAID SYNCHRONIZING UNIT COMPRISING A PULSE OSCILLATOR ARRANGED TO BE TRIGGERED IN RESPONSE TO SAID HORIZONTAL SYNCHRONIZING PULSES, A SAWTOOTH WAVE GENERATOR COUPLED TO SAID PULSE OSCILLATOR AND RESPONSIVE TO THE PULSE OUTPUT THEREOF TO PRODUCE A SAWTOOTH WAVE, A FIRST PHASE COMPARTOR FOR COMPARING SAID HORIZONTAL SYNCHRONIZING PULSES AND SAID SAWTOOTH WAVE AND FOR PRODUCING A CONTROL SIGNAL DETERMINED BY THE PHASE DIFFERENCE THEREBETWEEN, MEANS TO APPLY SAID CONTROL SIGNAL TO SAID PULSE OSCILLATOR TO CAUSE SAID PULSE OSCILLATOR TO HAVE AN OPERATING FREQUENCY APPROXIMATELY EQUAL TO THAT OF SAID HORIZONTAL SYNCHRONIZING PULSES, SAID PULSE OSCILLATOR BEING RESPONSIVE TO SAID HORIZONTAL SYNCHRONIZING PULSES TO BE DIRECTLY LOCKED IN FREQUENCY THERE-