| 摘要 |
PROBLEM TO BE SOLVED: To develop a liquid circulation device for an ink jet head having a small-sized and light-weight piezoelectric pump that is highly resistant to the temperature rise of a piezoelectric element and whose pump performance is hardly deteriorated.SOLUTION: A liquid circulation device comprises: a first tank (supply side ink chamber) including a discharge port for discharging liquid in a container and an in-flow port for making liquid flow into the container; a second tank (recovery side ink chamber) including an in-flow port in which liquid discharged from the first tank flows and a discharge port for discharging the liquid to the first tank; and a piezoelectric pump for feeding the liquid from the second tank to the first tank. Then, the liquid circulation device also has a control part which performs control so that a voltage characteristic applied in a direction where polarization of the piezoelectric element of the piezoelectric pump is enhanced becomes higher than a voltage characteristic applied in a direction opposite to the direction where the polarization of the piezoelectric element of the piezoelectric pump is enhanced.SELECTED DRAWING: Figure 5B |
