Patent ID: 8585190

Claim:
A liquid supply controller comprising: a liquid circulation controller that comprises a supply unit that supplies a liquid to a liquid droplet discharge unit and a recovery unit that recovers the liquid from the liquid droplet discharge unit, and that circulates the liquid at least according to a differential pressure between a supply pressure of the supply unit and a recovery pressure of the recovery unit; a back pressure setting unit that sets a back pressure that is a discharge pressure of the liquid droplet discharge unit based on the supply pressure and the recovery pressure set by the liquid circulation controller; a circulation amount obtaining unit that obtains a flow rate of the liquid circulated by the liquid circulation controller; a judging unit that judges whether or not the flow rate obtained by the circulation amount obtaining unit is a proper value; a differential pressure adjusting unit that adjusts the differential pressure while maintaining the back pressure within an allowable range when the judging unit judges that the flow rate is not the proper value; and a storage unit that stores in a table form a plurality of liquid circulation abilities and a pair of pressure setting values of the supply pressure and the recovery pressure for transitioning each of the plurality of liquid circulation abilities to a predetermined proper liquid circulation ability, wherein the differential pressure adjusting unit reads, from the table stored in the storage unit, based on an actual liquid circulation ability obtained by actual measurement, the pair of pressure setting values for transitioning the actually measured liquid circulation ability to the proper liquid circulation ability, and changes the pair of pressure setting values of the supply pressure and recovery pressure at the time of the actual measurement to the read pair of pressure setting values.