| 摘要 |
PROBLEM TO BE SOLVED: To stably vary a size of a dot on a medium to be printed by a method wherein a plurality of discharge openings are formed to one ink duct, and flow resistance from the ink duct to the discharge opening is varied at least in two or more kinds. SOLUTION: By forming two discharge openings 11, 12 such as first and second ones to one ink duct 10 per each one nozzle and varying areas of those discharge openings 11, 12, flow resistance of ink in those discharge openings 11, 12 is varied. Further, the flow resistance is generally proportional to a length of the duct, and reversely proportional to its sectional area. Since energy necessary for discharge of ink is approximately proportional to the flow resistance, by varying energy necessary for discharge of ink given as heat energy from a discharge heater 18 formed in the ink duct 10, a size of a dot is varied, and a smooth halftone image can be printed. |
