Patent ID: 8197046

Claim:
An ink-jet printer comprising: an ink circulation path comprising: an ink head having a nozzle face on which a plurality of nozzles are formed and discharging an ink from the nozzles in accordance with an image signal to perform a printing process on a recording medium; a first tank disposed so that a liquid level of ink stored in the first tank is on a same level as, or higher than, the nozzle face of the ink head in a gravitational direction, and being able to communicate with an atmosphere or to be shut off from the atmosphere; a second tank disposed so that a liquid level of ink stored in the second tank is lower than the nozzle face of the ink head in the gravitational direction, and being able to communicate with the atmosphere or to be shut off from the atmosphere; and a pump sending the ink in the second tank to the first tank; a pressure adjustment unit applying, when the second tank is shut off from the atmosphere, a negative pressure to the second tank, wherein the ink circulation path makes the first tank communicate with the atmosphere and shuts off the second tank from the atmosphere in an ink-circulation state period in which the ink is circulated, and shuts off the first tank from the atmosphere and makes the second tank communicate with the atmosphere in a no ink-circulation state period in which the ink is not circulated; and during the printing process, the ink-circulation state and the no ink-circulation state are switched.