Ink ejection arrangement having cooperating chamber wall edge portions and paddle edge portions

1. An ink ejection arrangement for a printhead integrated circuit, the arrangement comprising:

a fluid chamber having a fluid outlet nozzle and a fluid supply channel respectively defined in opposite walls of the chamber, the chamber defining chamber wall edge portions; and

a nozzle paddle operatively located in the chamber between the edge portions, the paddle having upturned edge portions which cooperate with the chamber wall edge portions, the paddle operatively displaceable upwards to eject ink from the fluid outlet nozzle, the paddle spaced from the chamber wall edge portions so that ink is able to flow between a front and rear of the paddle to allow refilling of the chamber with ink via the supply channel,

wherein the chamber wall edge portions are configured to reduce fluid flow through a space between said portions and the paddle when the paddle moves from a rest position to an ejection position.

2. The ejection nozzle of claim 1 , wherein the paddle is formed with a series of protrusions in a central portion thereof, the protrusions aiding in reducing outward ink flow from the centre of the paddle as the paddle moves upward to eject ink via the outlet nozzle.

3. The ejection nozzle of claim 1 , wherein the series of protrusions includes a plurality of truncated pyramidal protrusions.

4. The ejection nozzle of claim 1 , wherein the protrusions include a series of ridges, said ridges arranged parallel, concentric or intersecting, and said ridges shaped to be elliptical, circular, or arcuate.

5. The ejection nozzle of claim 1 , wherein the fluid supply channel is configured to encourage fluid flow into the chamber as the paddle moves from the ejection position to the rest position.

6. The ejection nozzle of claim 5 , having an angling into the chamber of a surface of the wall of the chamber around the fluid supply channel.