Liquid ejection printing apparatus and liquid supply method to be

Abstract

A liquid ejection printing apparatus performing printing by ejecting a liquid toward a printing medium includes a liquid ejection head portion having a liquid ejecting printing head ejecting a liquid and a first tank holding the liquid to be supplied to the head, a second tank holding a liquid to be supplied to the first tank and having an atmosphere communicating opening for introducing an atmospheric air, a third tank receiving the liquid from the first tank and capable of supplying the liquid to the second tank, a first liquid supply passage for communicating the first tank and the second tank, a second liquid supply passage for communicating the second tank and the third tank, a third liquid supply passage for communicating the third tank to the first tank, the first tank and the third tank each forming an enclosed space excluding supply passages connected respectively thereto, a pump capable of sucking a gas within the third tank provided in a passage other than the first, second and third supply passages and a first valve provided in the second supply passage for opening and closing the second liquid supply passage, and a second valve provided in the third tank for communicating the gas within the third tank to outside.