Inkjet printhead with multiple heater elements in parallel

1. An inkjet printhead comprising:

an array of ink chambers, each ink chamber having a plurality of nozzles and a thermal actuator for generating vapour bubbles to eject ink through the nozzle;

wherein the thermal actuator has a pair of contacts and at least two parallel current paths between the contacts, each of the current paths having a plurality of heater elements connected in series for nucleating a vapour bubble, the heater elements being suspended within the chamber, and each nozzle being associated with a respective heater element.

2. An inkjet printhead according to claim 1 wherein the heater elements nucleate their respective bubbles simultaneously with every activation of the actuator.

3. An inkjet printhead according to claim 1 wherein the thermal actuator has a cross bracing structure extending between intermediate points on the parallel current paths.

4. An inkjet printhead according to claim 3 wherein the cross bracing structure provides increased thermal inertia where it connects to each current path.

5. An inkjet printhead according to claim 3 wherein the cross bracing structure provides a droplet stem anchor.

6. An inkjet printhead according to claim 3 wherein the thermal actuator is formed from TiAlN.

7. An inkjet printhead according to claim 1 wherein each of the ink chambers have two nozzles.

8. An inkjet printhead according to claim 1 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 being regularly spaced along the heater element.

9. An inkjet printhead according to claim 1 wherein the nozzles are elliptical.

10. An inkjet printhead according to claim 9 wherein the major axes of the elliptical nozzles are aligned.