Abstract: An ink jet head includes a plurality of ejection orifices for ejecting ink; a common liquid chamber for storing temporarily the ink to be supplied to each of the ejection orifices; a plurality of ink passages, being separated by liquid passage walls, and each of which connects one of the ejection orifices to the common liquid chamber; and a plurality of energy generating elements provided one for one in each of the ink passages for generating energy to eject the ink from each of the ejection orifices; wherein the ejection orifices are grouped into a plurality of control blocks comprising a predetermined number of the ejection orifices in sequence so that the energy generating elements are driven by the block; and wherein walls are provided in the common liquid chamber, at the dividing lines between the control blocks, for impeding the ink movement in the liquid chamber, between the adjacent blocks.

Abstract: An ink jet head for effecting recording by selectively ejecting ink onto a recording material, includes an array of ejection outlets; a plurality of ink flow paths each having an ejection energy generating element for ejecting the ink, the ink flow paths being in fluid communication with ejection outlets; a common liquid chamber for supplying the ink to the a plurality of ink flow paths; wherein the plurality of the ejection energy generating elements are grouped into blocks of a predetermined number of ejection energy generating elements, and actuation timing for the ejection energy generating elements is deviated for each blocks; wherein the ejection outlets have different opening angles for respective blocks in a direction of reducing deviation of recording positions between respective blocks.