PURPOSE: To keep the liquid level of ink regardless of the quantity of the ink in an ink tank, by providing the air introducing pipe, which extends to the vicinity of the bottom part of an ink tank supplying ink, to an ink jet head and applying air pressure to the ink in the ink tank through air introducing pipe.
CONSTITUTION: At the time of the driving of an ink jet recording apparatus, equal air pressure Pa is applied to an ink tank 4 and an ink jet head so as tb be capable of keeping the ink in an ink emtting orifice stable. The air pressure Pa is propagated to an air introducing pipe 6 through an air inflow port 8 and an air chamber 9 to be applied to the ink in an ink storage chamber 10. At this time, the liquid level of the ink is formed at the position of the height 0 of the leading end part of the air introducing pipe 6 and, even when the ink in the ink storage chamber 10 is consumed, the air only corresponding to the consumption of the ink flows out into the ink storage chamber 10 from the air introducing pipe S to hold the liquid level of the ink to the point of the height 0. The height of the liquid level of the ink in the ink tank acting on the ink jet head at the time of driving can be kept constant regardless of the quantity of the ink in the ink tank and a good recording article can be obtained over a long period of time.
ODA HAJIME
AKAMI KENJI
