Pagewidth inkjet printhead with ink ejection devices having a series of protrusions to facilitate ink ejection

摘要

Provided is a pagewidth inkjet printhead which has a plurality of ink ejection devices. Each of these devices includes a substrate defining a fluid chamber having a fluid outlet nozzle and a fluid supply channel respectively defined in opposite walls of the chamber. The chamber also defines chamber wall edge portions. Each ejection device also includes a thermal actuator and a nozzle paddle operatively located in the chamber between the edge portions. The paddle is operatively displaceable upwards by the actuator to eject ink from the fluid outlet nozzle, with 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. The paddle is further 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.