Liquid supply apparatus, image forming apparatus and liquid supply method

摘要

The liquid supply apparatus has: a main tank which stores liquid; a sub tank which is disposed vertically above a recording head configured to eject the liquid and which is not connected to atmosphere, the sub tank being composed of a deformable member so that a volume of the sub tank is changed depending on a volume of the liquid in the sub tank; a first flow channel which connects the main tank with the sub tank; a second flow channel which connects the sub tank with the recording head; a flow rate determination device which determines a flow rate of the liquid in the second flow channel; a first pressure control device which controls an internal pressure of the main tank according to the flow rate determined by the flow rate determination device; and a second pressure control device which controls an internal pressure of the sub tank so as to fall within a prescribed range.