Patent ID: 7448710

Claim:
A liquid droplet ejection head, comprising: first nozzles which eject droplets of a first liquid to an ejection receiving medium; second nozzles which eject droplets of a second liquid to the ejection receiving medium, wherein the first nozzles and the second nozzles are arranged to cover the full width of the ejection receiving medium; first pressure chambers which are connected to the first nozzles and filled with the first liquid to be ejected from the first nozzles; first pressure generating devices which cause the first liquid to be ejected from the first nozzles by applying pressure to the first liquid inside the first pressure chambers; second pressure chambers which are connected to the second nozzles and filled with the second liquid to be ejected from the second nozzles; second pressure generating devices which cause the second liquid to be ejected from the second nozzles by applying pressure to the second liquid inside the second pressure chambers; and a nozzle plate in which the first nozzles and the second nozzles are formed, wherein the first nozzles and the second nozzles are arranged in a two-dimensional array and disposed adjacently in mutual proximity so as to be aligned in a sub-scanning direction which is parallel to a relative direction of movement of the ejection receiving medium and the liquid droplet ejection head, in such a manner that the first liquid and the second liquid ejected respectively from the first nozzle and the second nozzle that are arranged in mutual proximity are deposited at substantially same position on the ejection receiving medium, wherein the first pressure chambers and the second pressure chambers are arranged in a layered structure, in such a manner that the first pressure chambers and the second pressure chambers in different layers partially overlap with each other and non-overlapping regions thereof are aligned in the sub-scanning direction, wherein the first liquid having a relatively high viscosity is filled into the first pressure chambers formed in a layer which is nearer to the nozzle plate, and the second liquid having a relatively low viscosity is filled into the second pressure chambers formed in a layer which is further from the nozzle plate.