Patent ID: 7862142

Claim:
An ink jet head comprising: a body; a common ink storage chamber formed within the body; a common ink passage formed within the body configured to introduce ink supplied from an exterior of the body to the common ink storage chamber; an ink discharge passage configured to discharge ink within the common ink storage chamber to an exterior of the body; a common ink storage space including the common ink storage chamber, the common ink passage and the ink discharge passage, the common ink storage space being filled with ink; a valve configured to selectively open and close the ink discharge passage; a plurality of nozzles distributed on a first face of the body; a plurality of pressure chambers formed within the body, the number of the pressure chambers being equal to the number of the nozzles; a plurality of individual ink passages formed within the body, each individual ink passage extending from the common ink storage chamber to one of the nozzles through one of the pressure chambers; and an adjuster configured to allow volume change of the common ink storage space, wherein the adjuster includes a through-hole formed on a wall defining the ink discharge passage and a flexible sheet closing the through-hole and separating the ink discharge passage from atmosphere and the ink discharge passage is configured to discharge ink to an exterior of the body at a location separate from the nozzles.