| 摘要 |
PURPOSE:To remove bubbles fed from a nozzle to an ink channel by small-sized simple maintenance means by so trapping the bubbles in a communication passage as not to invade it into a pressurizing chamber. CONSTITUTION:An bubble trapping unit 28 made of a protrusion is provided at the bottom of an ink jet head at the board 1 side of an inner wall for partitioning a communication passage 4. The unit 28 is so formed with a smoothly inclined surface 28a as to reduce resistance in a direction directed from the passage 4 toward a nozzle 2 and with a stepped part 28b as to increase the resistance in a direction from the nozzle 2 toward a pressurizing chamber 3. The bubbles invaded from the nozzle 2 are prevented from being moved to the chamber 3 by the part 28b of the unit 28. The bubbles trapped in this manner are sucked to the nozzle 2 side and removed by the maintenance means. |
