Video printing process and apparatus

Abstract

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.