Patent ID: 7883187

Claim:
An ink jet printing apparatus comprising: an ink tank for storing ink; a print head including a common liquid chamber having an ink flow-in port, into which the ink flows from the ink tank, and an ink flow-out port for returning the ink to the ink tank, a discrete liquid chamber for supplying the ink to an ejection port for ejecting the ink from the common liquid chamber, and a gas-liquid separation member for making only gas flow out from the discrete liquid chamber; a circulation pressurization pump supplying the ink to the common liquid chamber from the ink tank via a first ink path; a circulation suction pump returning the ink to the ink tank from the common liquid chamber via a second ink path; and an air suction pump in communication with the discrete liquid chamber for sucking air from the discrete liquid chamber through the gas-liquid separation member; wherein while the circulation pressurization pump and the circulation suction pump are driven to cause ink to circulate, the air suction pump is driven to suck air from the discrete liquid chamber.