| 摘要 |
PURPOSE: To effectively deliver ink to a printing head in a method high in controllability by providing a pump means for applying pressure to ink toward a printing head, and a return means for returning a part of the ink not returned to an ink delivery means to the pump means to reflux the same to the printing head. CONSTITUTION: The ink from a printing head 12 flows in a container 58 to increase the ink amt. in a reservoir 56. At this time, pressure is generated in a return pipe 54 and, when the ink enters the container 58, air bubbles in the ink flowing through a return pipe 54 are released to the atmosphere. At the same time, a certain amt. of the ink 62 passing through an ink return pipe 64 is sucked. One end of the ink return pipe 64 communicates with the suction side of a pump 22 and the ink is taken out of the reservoir 56 by the sucking action of the pump to enter the pump 22. The pump 22 pressurizes the ink to return the same to the reservoir 56 through an ink supply pipe 24, an ink flow channel 38 and the ink return pipe 54. The reservoir 56 is arranged under the head 12 and, as a result, the pressure in the cavity 40 connected to the printing head 12 becomes below atmospheric pressure. |
