| 摘要 |
PURPOSE:To prevent air suction through an ink jet nozzle by forming an ink supply port to a pressure chamber in such a way that said port converges to the pressure chamber side and suddenly expands at the chamber. CONSTITUTION:A printer head consists of sequentially joint components such as a pressure plate 1, a nozzle plate 2, a supply plate 3, a bypass plate 4, a tank plate 5 and a blind plate 6. When the printer head is driven, ink is introduced into an ink chamber 9 from an ink fountain via an ink induction port 8, then the ink enters an opening 13 from the ink chamber 9, passing through a gradual contraction part 14 and a rapid expansion part 15 into a pressure chamber 11. When voltage is applied to a piezoelectric ceramics, the ink passes through a gradual contraction part 16, being ejected through an ink jet port 17. Consequently, it is possible to minimize an ink backflow into the ink chamber from the pressure chamber. Thus the backflow of ink can be prevented, and subsequently, the suction of air through the ink jet nozzle be checked. |
