Patent ID: 7950787

Claim:
A liquid ejection apparatus, comprising: a head capable of ejecting liquid; a first liquid storage unit which is installed in the apparatus so as to be replaceable by a user, which is capable of storing the liquid to be ejected from the head; a second liquid storage unit which is integrally formed with the apparatus body which is capable of storing liquid to be ejected from the head, the liquid stored in the second liquid storage unit being the same liquid as the liquid stored in the first liquid storage unit; and a selection-and-supply unit which is capable of selecting at least one liquid to be ejected from the head from the liquid stored in the first liquid storage unit and the liquid stored in the second liquid storage unit and supplying the selected the liquid to the head, wherein the selection-and-supply unit comprises: a first valve installed in a first liquid passage where liquid from the first liquid storage unit flows to the recording head which is capable of stopping or allowing the flow of liquid in the first liquid passage; a second valve installed in a second liquid passage where liquid from the second liquid storage unit flows to the recording head which is capable of stopping or allowing the flow of liquid in the second liquid passage; and a controller capable of controlling the first and second valves; wherein the controller closes the first valve and opens the second valve to cause the liquid stored in the second liquid storage unit to be supplied to the recording head when a maintenance operation is being performed; and wherein the controller opens the first valve and closes the second valve to cause the liquid stored in the first liquid storage unit to be supplied to the recording head during a ejecting process where the recording head ejects the liquid to a medium.