| 摘要 |
PROBLEM TO BE SOLVED: To execute high speed ejection of fine ink drops by gradually expanding a pressure generating chamber and to achieve accurate gradation printing by ejecting various sizes of ink drops from a big one to a small one by contracting the pressure generating chamber before ejecting ink drops. SOLUTION: In this recorder, a pressure generating chamber 11 is expanded or contracted by virtue of displacement of a piezoelectric actuator 15, thereby ejecting ink drops 17 from a nozzle 12. A control means 20 for applying a driving signal to the piezoelectric actuator 15 generates a first contracting signal for contracting the pressure generating chamber 11 without ejecting ink drops 17 from the nozzle 12, a first expanding signal for ejecting ink drops 17 by expanding the pressure generating chamber 11 following the first contracting signal and a second expanding signal for further expanding the pressure generating chamber 11 following the first expanding signal so as to quickly break an ink column ejected from the nozzle 12 and to return the unnecessary ink to a side of the nozzle. |
