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AssigneesEtablissement Public de Diffusion dit "Telediffusion de France", L'Etat Francais le Secretaire d'Etat aux Postes et Telecommunications
InventorsJean A. Pajus, Christiane S. Luneau
Estimating the term…
A multiple printing head, having k print points responds to binary samples hich represent a grid of points, that are continuously repeated. The m horizontal lines correspond to television lines, each line comprising n points. The vertical lines formed by the grid points are grouped to form n/k columns, each comprising k vertical lines. The point bits are transmitted to the printing head by the point bits of the first line and the last column, then by the point bits of the second line and the last column, and so on up to those of the m.sup.th line and the last column. The point bits of the first line and the last but one column are transmitted to the said printing head, then those of the second line and the last but one column, and so on up to those of the m.sup.th lines and the last but one column, then the actual support is again shifted as previously. Those transmission operations for the point bits, interrupted by head shifts, are repeated column by column up to print the points of the m.sup.th line of the first column. In the course of the bit transmission to the printing head, the point bits pass through a buffer memory from which they are read out to the printing head. The write operation is performed line by line in selecting the point bits belonging to the column under printing and to the line that follows the one whose point bits have just been written into the buffer memory. The selection of the data to be written is made either in the same frame of video signals or in different frames.
A process for printing two-dimensional images responsive to video signals by means of a multiple point printing head having k print points, the process comprising the steps of:
A system for producing two-dimensional steady television pictures from video signals, said system comprising means for continuously digitizing video signals representing said picture, means for extracting line sync pulses and signals frame sync pulses from the television video signal, k-stage register means, buffer memory means having independently controlled input and output operations, means responsive to digitizing clock signals for operating said k-stage shift register means in response to serial input data from an output the digitizing means, said k-stage shift register means having parallel outputs connected to respective inputs of said buffer memory, means for applying buffer memory data outputs to data input of a printing machine having a printing head means with a width of k points, first and second comparator means, two-input AND gate means having one input coupled for receiving clock signals and the other input coupled to an output of said first comparator means, first and second column counter means, one input of said first comparator means being connected to a data output of said first column counter means, and another input of said first comparator means being connected to a data output of said second column counter means, detecting means, the input of the first column counter means being connected to an overflow output of said cyclic k-stage counter driven by the digitizing clock signals and the input of the second column counter means being connected to said detector for detecting an actual shift by the printing machine means, first and second line counter means said first line counter means having data input coupled to receive line sync pulses and a data output coupled to one input of said second comparator means, the output of said second comparator means being coupled to one input of a 3-input AND gate, a second input of said AND gate being coupled to said first comparator means output, and a third input of said AND gate being coupled to the buffer memory output, an output of the 3-input AND gate being coupled to a write control input of the buffer memory means and to an input of said second line counter means, the buffer memory means comprising a busy/idle output indicating a partial busy condition of the memory, said busy/idle output being connected to start control input of the printing machine and to read output connected to a read control output of the printing machine, reset inputs of said first column counter and a cyclic point counter means being fed with said line sync pulses, and a reset input of said first line counter being fed with said frame sync pulses.
Dependencies are inferred from the claim text.