Inkjet printhead with multiple heater elements and cross bracing
View Patent ↗An inkjet printhead having: an array of ink chambers, each having a nozzle and a plurality of heater elements for generating vapour bubbles to eject ink through the nozzle, the heater elements being suspended for immersion in the ink; and, a cross bracing structure for maintaining the spacing between the heater elements.
1. An inkjet printhead comprising an array of ink chambers, each ink chamber having:
a nozzle; and
a heater element for generating vapour bubbles to eject ink through the nozzle, the heater element being suspended for immersion in the ink, and having a plurality of current paths connected in parallel, each current path having two portions having a reduced cross-section relative to the remainder of the current path, and
a cross bracing structure for connecting intermediate portions of the current paths.
2. An inkjet printhead according to claim 1 wherein the current paths nucleate bubbles simultaneously with every activation of the heater element.
3. An inkjet printhead according to claim 1 wherein the cross bracing structure provides sections of greater thermal inertia in the current paths.
4. An inkjet printhead according to claim 1 wherein the current paths of the heater element initiate a pressure pulse that is symmetrical about two orthogonal axes parallel to the plane of the nozzle, the orthogonal axes intersecting a mutually orthogonal axis extending through the centre of the nozzle.
5. An inkjet printhead according to claim 1 wherein the heater elements are formed from TiAlN.
6. An inkjet printhead according to claim 1 wherein the cross bracing structure provides a droplet stem anchor.
7. An inkjet printhead according to claim 1 wherein each of the ink chambers have a plurality of nozzles; wherein during use,
the actuator simultaneously ejects ink through all the nozzles of the chamber.
8. An inkjet printhead according to claim 7 wherein each of the ink chambers have two nozzles.
9. An inkjet printhead according to claim 7 wherein the nozzles in each chamber are arranged in a line parallel to the length of the heater element with the central axes of the nozzles are regularly spaced along the heater element.
10. An inkjet printhead according to claim 7 wherein the nozzles are elliptical.
11. An inkjet printhead according to claim 10 wherein the major axes of the elliptical nozzles are aligned.