| 摘要 |
PURPOSE:To prevent the penetration of dust into an ink jet nozzle by collecting dust outside a printer by providing a multistage slit between the air outside the ink jet nozzle protecting case on the axial line of the ink jet nozzle and the ink jet nozzle. CONSTITUTION:In an ink jet printer, a multistage slit 3 is provided to the inside or outside of the ink jet orifice of an ink jet nozzle protecting case 2. The multistage slit generates the change of air pressure in many stepped parts by different cross-sectional areas and prevents the straight advance of invaded air to change the advance direction thereof to the outside along a wall surface and dust is weakened in its advance force by reduced pressure to be sucked in the stepped parts so as to be bonded to a wall. By catching the dust penetrating from the outside of the protecting case 2 by the action of the multistage slit 3, the penetration of dust into an ink jet nozzle 1 is prevented. |
