Patent ID: 7407241

Claim:
An ink-jet head device comprising: an ink-jet head for jetting ink; a sub-tank for reserving ink to be supplied to the ink-jet head; a main tank for reserving ink to refill the sub-tank; a movable carriage, including the ink-jet head; and a negative pressure generating unit connected to the sub-tank for generating negative pressure inside the sub-tank relative to the ink jet head; a three-way flow path that connects the sub tank, the main tank, and the ink-jet head to one another, such that the sub tank is located above the ink-jet head and the main tank is located above the sub tank; a flow path switching unit, disposed at a junction of the three-way flow path, for selectively switching a flow path connecting the sub tank to the main tank and a flow path connecting the sub tank to the ink-jet head, without causing the ink-jet head and the main tank to communicate with each other; and a flow path controller for controlling the flow path switching unit.