Sweep marker circuit

Claim 1

APPARATUS FOR DISPLAYING AN INPUT SIGNAL USING AN ELECTRON BEAM OF A CATHODE-RAY OSCILLOSCOPE TUBE, SAID APPARATUS COMPRISING: A FIRST COMPARATOR HAVING A PAIR OF INPUTS AND ADAPTED TO PRODUCE AN OUTPUT IN RESPONSE TO SIGNALS APPLIED TO THE INPUTS THEREOF BEARING A PREDETERMINED RELATIONSHIP TO EACH OTHER; MEANS GENERATING A SWEEP SIGNAL; MEANS GENERATING A RAMP SIGNAL AT EACH SELECTED RECURRENCE OF THE INPUT SIGNAL TO BE DISPLAYED; A SOURCE OF REFERENCE VOLTAGE; MEANS CONNECTED TO AN INPUT OF SAID COMPARATOR FOR APPLYING THERETO THE COMBINATION OF SAID SWEEP SIGNAL AND REFERENCE VOLTAGE; MEANS TO APPLY SAID RAMP SIGNAL TO THE OTHER OF SAID INPUTS OF THE FIRST COMPARATOR; A SECOND COMPARATOR HAVING A PAIR OF INPUTS AND ADAPTED TO PRODUCE AN OUTPUT SIGNAL IN RESPONSE TO SIGNALS APPLIED TO THE INPUTS THEREOF BEARING A PREDETERMINED RELATIONSHIP TO EACH OTHER; MEANS TO APPLY SAID REFERENCE VOLTAGE AND SAID SWEEP SIGNAL TO THE INPUTS OF SAID SECOND COMPARATOR; AND MEANS RESPONSIVE TO THE OUTPUT OF SAID SECOND COMPARATOR TO ALTER THE INTENSITY OF THE ELECTRON BEAM OF SAID CATHODE-RAY OSCILLOSCOPE TUBE.