| 摘要 |
PURPOSE:To eliminate the occurrence of blocking at the same time as air bubbles are discharged by using a system in which when air bubble-trapping capacity is increased and blocking occurs and when air bubbles trapped are discharged, a sufficient pressurizing force or a negative pressure suction force is invited to act through a nozzle port. CONSTITUTION:A bypath-lowering flow path 22 extending downwards from the side of an air bubble trap 10 having a sufficiently large trapping capacity is provided, and its outlet is led to a branched lower flow path 7. A fluid resistor 23, e.g., throttle or filter, is provided right before the upstream side of the outlet of the flow path 22. A part of air bubbles accumulated in the trap 10 is allowed to escape smoothly to the nozzle through the flow paths 22 and 7 and the head liquid path 9 for discharge, and at the same time the occurrence of blocking is eliminated. The air bubbles are absorbed under negative pressures by a negative pressure pump to reduce it from atmospheric pressure state A to B. Air bubbles accumulated to A are expanded and partly ride on ink flow and then discharged from the nozzle. |
