Patent ID: 8870315

Claim:
An image forming apparatus comprising: an ink tank configured to contain ink; a head unit having a nozzle configured to eject the ink; a liquid feed path configured to feed the ink contained in the ink tank to the head unit; a liquid feed unit configured to feed the ink contained in the ink tank to the head unit through the liquid feed path, wherein the liquid feed unit is configured to: execute a main purge of feeding the ink to the head unit at a predetermined flow rate; and execute a preliminary purge of feeding the ink to the head unit at a flow rate not higher than the predetermined flow rate, wherein the preliminary purge is executed prior to the main purge; and a liquid-feed status detection unit configured to detect a status of the ink fed to the head unit; a time counting unit configured to measure, based on a detection result in the liquid-feed status detection unit, a stop time, wherein the stop time is determined by calculating a duration of time for which the ink was stopped from being fed to the head unit; an ink temperature detection unit configured to detect an ink temperature of the ink supplied to the head unit; a first liquid feed control unit configured to: instruct the liquid feed unit to execute the preliminary purge, wherein the first liquid feed control unit is configured to instruct the liquid feed unit to execute the preliminary purge when the stop time is not shorter than a first time, and wherein the stop time is measured by the time counting unit; and instruct the liquid feed unit not to execute the preliminary purge when the stop time is shorter than the first time; and a second liquid feed control unit configured to instruct the liquid feed unit to execute the main purge, wherein the second liquid feed control unit is configured to set the predetermined flow rate based on both the stop time measured by the time counting unit and the ink temperature detected by the ink temperature detection unit.