Patent ID: 7185974

Claim:
An ink-jet recording apparatus comprising: a printing head which has an ink discharge port for discharging an ink; an ink container which stores the ink; and a buffer tank which stores the ink to be supplied to the printing head and which has an outside air-connecting passage for connecting an upper space of the buffer tank to outside air, an ink-introducing tube having an open end in the buffer tank for introducing the ink into the buffer tank from the ink container through the open end, and an outside air-introducing tube having an open end in the buffer tank for introducing the outside air into the ink container through the open end, wherein: the open end of the outside air-introducing tube is positioned at a height position higher than that of the open end of the ink-introducing tube, and a horizontal cross-sectional area in the buffer tank at the height position of the open end of the outside air-introducing tube is smaller than horizontal cross-sectional areas in the buffer tank at higher positions than the height position, and a bottom of the buffer tank is formed to have a substantially one-stepped structure as viewed in a vertical sectional view.