| 摘要 |
PURPOSE:To prevent an ink flow path from being closed with a bubble by a method wherein ink is pressurized by a pressurizing pump as well as sucked by a suction pump, and a constant pressurizing value is always kept by a relief value. CONSTITUTION:When bubbles or the like stagnate inside a head 1, a buffer tank 2, or the like, a motor 27 is driven with the head 1 capped with a cap 4 to actuate a pressurizing pump 28, and a motor 6 is driven to actuate a suction pump 7. In this manner, a pressurizing air is fed to an ink tank 3, whereby ink in the buffer tank 2 and an ink flow path of the head 1 is pressurized. This pressurization results in the shrinking bubble in the ink flow path, which prevents the ink flow path from being closed, thus ensuring a smooth ink flow. On the other hand, the pressurized ink and bubble in the head 1 are sucked out of a nozzle 1a by the suction pump 7 to be discharged to a waste liquid tank 8. In addition, when the pressure of a pressurizing air is increased to a fixed value or more, an excessive air is released through a relief valve 29. Thus, the pressurizing value can be always kept constant. |
