An ink jet printing nozzle arrangement is disclosed including an ink chamber having an ink ejection nozzle in one wall thereof for the ejection of ink from the ink chamber; a moveable paddle vane located within the ink chamber; an actuator means adapted to move the paddle vane so as to cause ink within the ink chamber to be ejected from the ink ejection nozzle; wherein the paddle vane includes a concave surface in the area adjacent the ink ejection nozzle. Preferably, the paddle vane includes a cup shaped surface in the area adjacent the ink ejection nozzle. The nozzle arrangement can be formed utilizing normal micro-electro mechanical construction techniques and the concave surface can be formed as the result of the deposition of a film over a pit. The actuator means can include an actuating portion located externally to the nozzle chamber and operational in an external ambient atmosphere of the arrangement. The ink chamber can further include a slot defined in a wall thereof such that the actuator means communicates with the moveable paddle vane through the slot. The actuator means can comprise a thermal actuator which includes a conductive heater element having a high bend efficiency such that when an electric current is passed through the conductive heater element, the heater element undergoes thermal expansion causing the actuator means to move the paddle towards the ink ejection nozzle. Preferably, the external surfaces of the slot are profiled so as to minimize any wicking of the ink out of the slot. The profile can include a surface having a protruding rim around the slot and the actuator means can be shaped so as to minimize wicking of ink along the actuator means.
CROSS REFERENCES TO RELATED APPLICATIONS
The following Australian provisional patent applications are hereby incorporated by cross-reference. For the purposes of location and identification, U.S. patent applications identified by their U.S. patent application serial numbers (USSN) are listed alongside the Australian applications from which the US patent applications claim the right of priority.
An ink jet printhead chip includes a substrate. Drive circuitry is positioned in the substrate. A plurality of nozzle arrangements is positioned on the substrate. Each nozzle arrangement includes nozzle chamber walls and a roof wall that define a nozzle chamber and an ink ejection port in the roof wall in fluid communication with the nozzle chamber. An ink pusher is operatively positioned with respect to the nozzle chamber and is displaceable through a range of between 1 micron and 5 microns to eject ink from the ink ejection port. An actuator is connected to the drive circuitry and the ink pusher to displace the ink pusher on receipt of an electrical signal from the drive circuitry.
An inkjet printhead is provided comprising ink ejection arrangements of an ink chamber, a nozzle and an ink ejector. The ink chamber is arranged in fluid communication with an ink supply channel via an aperture so as to supply ink to the nozzle, with the ink ejector arranged within the aperture. The ink ejector is operable to cause ejection of ink from the nozzle and resupply of ink to the ink chamber from the ink supply channel, and incorporates a movable paddle having a non-planar profile configured to control the flow of ink between the ink chamber and the ink supply channel during ejection and resupply.
An inkjet printhead is provided comprising ink ejection arrangements of an ink chamber, a nozzle defined in a first wall of the ink chamber and an ink ejector positioned within an aperture defined in an opposite, second wall of the ink chamber. The ink chamber is arranged in fluid communication with an ink supply channel via the aperture so as to supply ink to the nozzle. The ink ejector incorporates a movable paddle which is operable to cause ejection of ink from the nozzle and resupply of ink to the ink chamber from the ink supply channel. The adjacent, peripheral regions of the second wall and the paddle are configured to define a bicuspid valve between the ink chamber and the ink supply channel.
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.
An inkjet nozzle arrangement includes a substrate that defines an ink supply channel. Integrated circuitry is positioned on the substrate. An ink chamber structure is positioned on the substrate and defines an ink chamber in fluid communication with the ink supply channel and an ink ejection port in fluid communication with the ink chamber. A paddle is positioned in the ink chamber and is movable to eject ink from the ink ejection port. The paddle has a generally concave cross section with respect to the ink ejection port. An actuator is connected to the integrated circuitry and is operable on the paddle to displace the paddle.
