Abstract: A method of depositing spots of liquid ink upon selected pixel centers on a substrate having poor ink absorptive properties so as to prevent the flow of liquid ink from one spot to an overlapping adjacent one. The line of information is printed in at least two passes so as to deposit spots of liquid ink on selected pixel centers in a checkerboard pattern wherein only diagonally adjacent pixel areas are deposited in the same pass. On the second pass the complementary checkerboard pattern is deposited. Ink is not deposited on horizontally or vertically adjacent pixel areas during the single pass since the spots on these adjacent areas have overlapping portions.

Abstract: A traveling wave droplet generator for a continuous stream ink jet printer comprising an ink filled tube connected in the vicinity of one end to an ink reservoir. A piezoelectric driver assembly is mounted at the fill end of the tube. The tube has openings connecting to orifices of an aperture plate bonded thereto. The tube has a terminator at the end opposite to the piezoelectric driver to suppress reflection and standing wave formation. The ink streams emitted through the nozzles of the aperture plate are stimulated by the traveling wave causing the streams to break up at predetermined distances from the nozzles.