US Patent 9751317 Liquid ejection device

A liquid ejection device includes a liquid ejection head, a supply tank connected to the liquid ejection head via a first flow path, a recovery tank connected to the liquid ejection head via a second flow path, a circulation pump arranged in a third flow path, a pressure pump arranged in a fourth flow path configured to connect the recovery tank and the liquid ejection head to each other, and a control portion configured to switch between liquid ejection operation in which liquid is ejected from the liquid ejection head while the liquid is circulated along the first to third flow paths and pressurizing recovery operation in which the liquid pressurized by the pressure pump is supplied to the liquid ejection head via the fourth flow path.