Patent ID: 7198351

Claim:
A head unit cleaning method for cleaning a head unit including: an ink jet head having a plurality of ink channels, the ink jet head ejecting ink while the head unit is in a printing posture; a buffer tank for storing ink to be supplied to the ink jet head, the buffer tank having a top wall formed with a first port and a second port; and a manifold disposed between and connected to the ink jet head and the buffer tank, the manifold distributing ink from the buffer tank to the plurality of ink channels in the ink jet head, the cleaning method comprising: introducing cleaning fluid into the buffer tank through the first port to remove foreign matter from the head unit through the second port; turning the head unit upside down with respect to the printing posture so that the second port is located in a lowermost position and the top wall slants down toward the second port; and removing the cleaning fluid remaining in the head unit through the second port.