INK JET PRINTING APPARATUS

摘要

An ink jet printing system suited to the making of large scale graphics, such as outdoor billboards, includes an endless carrier for moving a plurality of rigid flat panels, onto which a graphic is to be printed in sections, repetitively past an ink jet printing station. At the printing station each panel moves in purely rectilinear fashion in a direction parallel to its ink drop receiving face so that such face remains essentially at a uniform spacing from the ink jet printing heads of the printing station as the printing occurs. A means for timing the operation of the ink jet heads takes into account irregularities or changes in the motion of the panels past the printing station so that the ink drops are correctly placed despite such irregularities or changes. me ink jet heads can eject relatively large drops of pigmented ink. In the case of polychromatic half-tone printing, for each pixel of a panel different colors are printed at substantially different times so that the printed ink drops of one color can dry before those of another color are printed, and a heating means may be used to enhance the drying.