| 摘要 |
PROBLEM TO BE SOLVED: To improve the energy efficiency of an ink jet device by making the depth of the area between the expansible member of an ink channel and a nozzle larger than both of the depth of the adjacent area of the expansible member and the height of the nozzle. SOLUTION: When an ink droplet is required, a piezoelectric element 22 is contracted and ink is sucked in the upstream part 24 of an ink channel from an ink reservoir 14. At the same time, negative pressure acts on the ink in both of the downstream part 26 of the ink channel and a nozzle 18. Whereupon, the air/liquid meniscus in the nozzle 18 moves slightly inwardly but the meniscus of the nozzle 18 does not move over a stepped part 30. When the element is again expanded by the rear edge of a pulse signal, a positive pressure wave is formed in an adjacent part 24 to propagate in the direction of the ink reservoir 14 and the direction of the nozzle 18 within the ink channel 16. The wave front propagating to the nozzle 18 passes through the downstream part 26 to be horizontally converged to the nozzle 18 at a taper part. Since the ink channel merely changes gradually in the downstream part 26, reflected energy loss is not almost generated before the pressure wave arrives at the stepped part 30. |
