| 摘要 |
PURPOSE:To prevent an ink drom dripping from a nozzle and remove bubbles from the interior of a head, by a method wherein a pressure higher than a printing pressure is applied to a head part to start ejection, and immediately after the starting of ejection, a valve is opened to permit an ink to flow. CONSTITUTION:When a switch is turned ON, a pump (Pu) 2 is driven, and an ejected liquid is stored in an accumulator part 3 with a rise in pressure, since a valve V1 is still closed. The pressure thus accumulated is set to be higher than the printing pressure. After a lapse of time T1, the valve V1 is turned ON, and the liquid stored with the pressure accumulated is fed into the head 4. Therefore, since jetting of an ink is started at a pressure higher than the ordinary printing pressure, dripping of the ink or the like does not occur at the rise of ejection. After a lapse of time T2, a valve V2 is opened, and the pressure inside the head is lowered at a relatively high rate. After a further lapse of time T3, the pressure P2 inside the head 4 becomes equal to the printing pressure, and the valve V2 is turned OFF. Thereafter, the quantity of the ink supplied from the pump 2 is balanced with the quantity of the ink ejected from the head 4, and the pressure inside the head is stabilized. |
