Sequential dot, digitally encoded television system

Claim 1

A sequential dot, digitally encoded, raster-type television transmission system comprising: input circuit means for receiving a time-based video signal having recurrent line and frame synchronizing signals; sequential dot video output circuit means; means for generating a train of rEcurrent sampling signals having a frequency where fv is the frequency of said frame synchronizing signals, L is the number of lines in one frame, D is a predetermined number of picture elements in one line, n1 is the vertical interlace ratio and n2 is a predetermined dot interlace ratio, the quotient LD/n1n2 being irreducible; means for generating a train of recurrent timing signals having a frequency fc fen2; means for actuating said timing signal generating means in response to each said line synchronizing signal thereby to initiate a said train of timing signals; and means for terminating each said train of timing signals in response to D timing signals; fc being such that each interval between successive line synchronizing signals is longer than D timing signals; said sampling signal generating means being responsive to said timing signals; means for coupling said input circuit means to said output circuit means in response to said train of sampling signals thereby to pass analogue video signals from said input circuit means to said output circuit means; means for detecting the amplitudes of said sampled video signals and for providing signals respectively responsive to a plurality of predetermined amplitude levels thereof; and means for digitally encoding said last-named signals.