Patent ID: 8506060

Claim:
An ink supply device for an inkjet printer, comprising: a sub-tank having an ink chamber to store liquid ink and to be connected to a print head configured to eject the liquid ink via a head-side supply passage, the sub-tank having a plurality of supply holes which connect the ink chamber and the head-side supply passage, at least two of the plurality of supply holes having their openings on the ink chamber side formed at different heights; and a main tank connected to the sub-tank and to contain the liquid ink to be supplied to the ink chamber, wherein the ink chamber has a supply ink chamber and a detection ink chamber communicating with each other, the supply ink chamber communicating with an ink inlet opening connected to the main tank, the detection ink chamber receiving a level indicator member floating on the liquid ink to freely move in a vertical direction, and wherein the sub-tank comprises a level detection portion configured to detect an ink level of the ink chamber by detecting a position of the level indicator member in the vertical direction.