Patent ID: 8308263

Claim:
A droplet ejection apparatus comprising: a plurality of droplet ejection units each respectively including a supply port for supplying liquid, a discharge port for discharging the liquid, and an ejection mechanism that ejects the supplied liquid as droplets; a common supply flow path that supplies the liquid to the plurality of droplet ejection units; a common discharge flow path that recovers the liquid from the plurality of droplet ejection units; a plurality of supply flow paths that each connect the supply port of each of the plurality of droplet ejection units to the common supply flow path; a plurality of openable mechanisms provided at the plurality of supply flow paths, respectively; a plurality of discharge flow paths that each connect the discharge port of each of the plurality of droplet ejection units to the common discharge flow path; a plurality of one-way valves that are respectively provided at the plurality of discharge flow paths to block the flow of the liquid from the common discharge flow path toward the discharge ports of the respective droplet ejection units; a pressure applying unit that applies pressure so that a pressure in the plurality of discharge flow paths at the common discharge flow path side with respect to the respective one-way valves is higher than the plurality of discharge flow paths at the discharge port side; and a controller that when performing a maintenance operation of a selected droplet ejection unit, applies a pressure with the pressure applying unit so that the pressure in the plurality of discharge flow paths at the common discharge flow path side with respect to the respective one-way valves is higher than the plurality of discharge flow paths at the discharge port side, and opens only the openable mechanism corresponding to the selected droplet ejection unit from among the plurality of openable mechanisms.