| 摘要 |
PROBLEM TO BE SOLVED: To provide an inkjet head which can enhance concentration capability of ink and ejection stability, and to provide its control method. SOLUTION: The inkjet head 10 has an ejection electrode 18 and a guard electrode 20 at a discharge opening substrate 16 where a discharge opening 28 is formed. A guard electrode control part 35 applies a pulse voltage to the guard electrode 20 while controlling the voltage which has the same frequency as that of a driving voltage applied to the ejection electrode and which alternately repeats a positive voltage and a negative voltage. At the time of ejection of the ink, color material particles are migrated and concentrated to an ink liquid level of the discharge opening by applying the negative voltage to the guard electrode 20. At the time of non ejection of the ink, a meniscus of the ink at the discharge opening is suppressed by an electric field directed towards the ejection electrode from the guard electrode 20 by applying the positive voltage to the guard electrode 20. Accordingly, while the concentration capability of ink is kept, an unnecessary overflow of the ink is prevented and the ejection stability is enhanced. COPYRIGHT: (C)2006,JPO&NCIPI
|
