Patent ID: 8123339

Claim:
A liquid ejection head, comprising: a plurality of orifices configured to eject droplets of liquid; a plurality of chambers in communication with the plurality of orifices; a plurality of fluid resistance portions in communication with the plurality of chambers, each fluid resistance portion of the plurality of resistance portions having a smaller width than a width of each chamber of the plurality of chambers; a plurality of passage groups arrayed in one direction, each passage group of the plurality of passage groups including at least two corresponding adjacent liquid passages, and each liquid passage of the at least two adjacent liquid passages in the passage group being formed by at least one chamber of the plurality of chambers and at least one fluid resistance portion of the plurality of the fluid resistance portions; a plurality of first partitions, each specific first partition of the plurality of first partitions being configured to separate two adjacent liquid passages of a corresponding specific passage group of the plurality of passage groups and to separate adjacent fluid resistance portions of the respective adjacent liquid passages; and a plurality of second partitions, each specific second partition of the plurality of second partitions being configured of a material to separate adjacent passage groups of the plurality of passage groups and to separate adjacent fluid resistance portions in the respective adjacent passage groups, wherein the each specific first partition is provided with at least one void therein and the each specific second partition configured of the material is not provided with a void, and wherein for each specific first partition amongst the plurality of first partitions, there is at least one void between the adjacent fluid resistance portions separated by the specific first partition, and for each specific second partition amongst the plurality of second partitions, there is no void between the adjacent fluid resistance portions separated by the specific second partition.