US Patent 7681999 Ink-jet printing head

An ink-jet printing head having a cavity unit, the cavity unit including a plurality of nozzles for ejecting an ink, a plurality of pressure chambers communicating with the respective nozzles, a common manifold chamber for distributing the ink into the plurality of pressure chambers, and a flexible plate having the plurality of nozzles and including a wall portion which partly defines the common manifold chamber and which constitutes a damper portion, wherein the damper portion absorbs a pressure wave of the ink propagating from each selected one of the pressure chambers to the common manifold chamber, when the ink in each selected pressure chamber is pressurized to eject the ink from the corresponding nozzle.