Patent ID: 7997707

Claim:
A liquid ejection device comprising: a liquid cartridge having; a liquid supply port through which a liquid contained in the liquid cartridge is allowed to be supplied to an outside of the liquid cartridge; a liquid supply chamber defined in the liquid cartridge and configured to communicate with the outside through the liquid supply port; and a first liquid storage chamber defined in the liquid cartridge and configured to communicate with the liquid supply chamber via a first communicating port; and a main unit comprising: a liquid ejection head configured to eject the liquid; a mounting unit to which the liquid cartridge is removably mounted; and a sub tank configured to allow fluid communication between the liquid cartridge and the liquid ejection head, wherein the sub tank has: a liquid inflow port connectable to the liquid supply port of the liquid cartridge in a state where the liquid cartridge is mounted to the mounting unit; a liquid outlet port through which the liquid contained in the sub tank is allowed to flow out toward the liquid ejection head; a liquid inflow chamber configured to communicate with the outside of the main unit through the liquid inlet port, the liquid inflow chamber allowing the liquid to be supplied from the liquid cartridge through the liquid inflow port in the state where the liquid cartridge is mounted to the mounting unit: a second liquid storage chamber configured to communicate with the liquid inflow chamber through a second communicating port and to store the liquid supplied from the liquid inflow chamber, the liquid stored in the second liquid storage chamber being allowed to flow out to the liquid ejection head through the liquid outflow port; and an atmosphere opening port configured to allow the second liquid storage chamber to communicate with an atmosphere, and wherein the first communicating port, the second communicating port, and the liquid outflow port are positioned lower than the liquid supply port in the state where the liquid cartridge is mounted to the mounting unit.