| 摘要 |
PURPOSE:To maintain a stable operation of the ink jet head on making the quantity of both bubbles and dissolved air in the ink a fixed value or less by providing a bubble detecting device and a bubble removal promoting device. CONSTITUTION:When bubbles are mixed in the ink 7, the electrostriction vibrator 3, vibrating plate 4 and motional impedance of the ink cell 7 are changed, the detector of the head driving and bubble detecting circuit 8 detects the change, the control corcuit 9 is started to operate the bubble removal promoting device 11 (heater, for example), a control signal CONT is provided to interrupt the normal picture printing or to give a warning. The bubble collector 10 is put between the ink tank 12 and the ink jet head 2 to remove bubbles, and moreover, when the bubble removal promoting device 11 is operated, bubbles can effectively be caught and removed. |
