Patent ID: 7192130

Claim:
An ink jet head comprising: a pressure chamber that stores an ink and has an orifice: a filter plate including a through hole portion and a filter portion, the through hole portion disposed separately from the filter portion by a certain gap; a supply unit that supplies the ink through the filter portion to the pressure chamber; and a jetting unit that jets ink droplets through the orifice from the pressure chamber; wherein the filter portion has a first aperture ratio; at least one first through hole is formed on the through hole portion so that the through hole portion has a second aperture ratio; and the first aperture ratio is smaller than the second aperture ratio; wherein the filter portion includes a first groove on a front surface of the filter portion; the filter portion includes a second groove on a back surface of the filter portion, the second groove extends in a direction perpendicular to the first groove; and a second through hole is in an area of the filter portion where the first groove and the second groove overlap.