Patent ID: 8205979

Claim:
A liquid ejection head comprising: a plurality of ejection orifices configured to allow liquid to be ejected therethrough; a plurality of passages communicating with the plurality of respective ejection orifices and with a plurality of respective pressure chambers, each of the plurality of pressure chambers accommodating an energy generating element therein, the energy generating element being configured to generate energy for ejecting the liquid; a supply port configured to supply the liquid to the plurality of passages; and a filter including a plurality of substantially cylindrical members arranged in a region between the supply port and the plurality of passages, the filter having a plurality of openings, wherein each of the plurality of ejection orifices has a cross section having a substantially circular shape with a larger diameter and a smaller diameter in a direction substantially perpendicular to a direction in which the liquid is ejected, wherein each of the plurality of openings of the filter has a cross section having a substantially rectangular shape with a longer side and a shorter side in a direction substantially perpendicular to a direction in which the liquid is supplied, and wherein the following relationships are satisfied: D1>L1, D1<D2, and D2>L2≧D1 where D 1 is the smaller diameter of the ejection orifice, D 2 is the larger diameter, L 1 is the shorter side of the opening, and L 2 is the longer side.