Patent ID: 7438403

Claim:
An inkjet printhead comprising: a cavity unit having: a plurality of nozzles which are open in a surface of the cavity unit and arranged in a row; a plurality of pressure chambers formed in a row in the cavity unit to correspond to the nozzles; and a common-chamber member in which a common ink chamber is formed, the common ink chamber being connected, at at least one ink introduction place, to an ink supply source storing ink so as to receive the ink therefrom and distribute the ink to the pressure chambers; an actuator unit superposed on the cavity unit to selectively pressurize the ink in each of the pressure chambers to eject a droplet of the ink from the nozzle corresponding to the pressure chamber; the common ink chamber extending along the row of the pressure chambers so as to overlap at least a part of each pressure chamber when seen in a direction of superposition of the cavity unit and the actuator unit; and a compensating member constituted by a material having a rigidity lower than that of a material of the common-chamber member, and disposed in the common ink chamber and in contact with the ink, at at least a remote portion far from the at least one ink introduction place, so that a cross-sectional area of the common ink chamber perpendicular to the longitudinal direction thereof gradually decreases at least at the remote portion in a direction away from each of the at least one ink introduction place, a cross-sectional area of the compensating member increases as the cross-sectional area of the common ink chamber decreases, and a supporting rigidity of the common-chamber member with respect to the pressure chambers is substantially uniform across a region corresponding to the row of the pressure chambers, along the direction of the row of the pressure chambers.