Patent ID: 7192132

Claim:
An ink jet head unit connected to an ink supply source, comprising: a head chip, having a first face formed with nozzle orifices from which ink is ejected, and a second face formed with at least one ink inlet communicated with the nozzle orifices; an ink passage communicating the nozzle orifices with the ink supply source to supply ink to be ejected; a filter, disposed in the ink passage at an upstream side of the ink inlet, the filter having a first face directed to an upstream side of the ink passage; a cover member, which covers at least a part of the first face of the filter, the cover member being constructed to allow ink in the ink passage to pass through while preventing air bubbles contained in the ink from coming in contact with the first face of the filter; and a damping chamber forming member, fixed to the second face of the head chip, the damping chamber forming member having at least one damping chamber for dampening pressure fluctuation occurred therein, wherein the filter and the cover member are disposed between the ink inlet and the damping chamber, and wherein the cover member is placed so as to come in contact with the first face of the filter.