Variable velocity halftone facsimile system

Claim 1

A VARIABLE VELOCITY FACSIMILE SYSTEM COMPRISING MEANS FOR GENERATING A FREQUENCY MODULATED SIGNAL, THE FREQUENCY OF WHICH VARIES WITH THE INFORMATION CONTAINED IN A SCANNED IMAGE; A FIRST LIMITER CONNECTED TO SAID GENERATING MEANS; A SECOND LIMITER; A PHASE SHIFT NETWORK CONNECTED BETWEEN SAID GENERATING MEANS AND SAID SECOND LIMITER; FIRST AND SECOND BISTABLE MULTIVIBRATORS EACH HAVING TWO OUTPUTS WHICH ARE OUT OF PHASE WITH RESPECT TO EACH OTHER, SAID FIRST LIMITER BEING CONNECTED TO SAID FIRST MULTIVIBRATOR AND SAID SECOND LIMITER BEING CONNECTED TO SAID SECOND MULTIVIBRATOR; FIRST ADDING MEANS CONNECTED TO THE FIRST OUTPUTS OF SAID FIRST AND SECOND MULTIVIBRATORS; SECOND ADDING MEANS CONNECTED TO THE SECOND OUTPUTS OF SAID MULTIVIBRATORS; PULSE COMBINING MEANS CONNECTED TO SAID FIRST AND SECOND ADDING MEANS FOR PRODUCING AN OUTPUT PULSE WHENEVER BOTH INPUTS TO SAID FIRST ADDER OR BOTH INPUTS TO SAID SECOND ADDER ARE POSITIVE; A CAPACITOR FOR GENERATING A SAWTOOTH WAVEFORM; CURRENT CONTROL MEANS COUPLING SAID PULSE COMBINING MEANS TO SAID STORAGE MEANS; SCAN CONTROL MEANS FOR DETERMINING RATE AT WHICH THE IMAGE IS SCANNED; AMPLIFIER MEANS FOR CONNECTING SAID CAPACITOR TO SAID SCAN CONTROL MEANS; AND MEANS FOR DISCHARGING SAID CAPACITOR.