Inkjet printhead having an array of displacable nozzles
View Patent ↗An inkjet printhead with an array of nozzle assemblies ( 10 ) formed on a supporting substrate ( 16 ). Each nozzle has a chamber ( 34 ) for holding ink, each nozzle chamber being partially defined by the nozzle that defines a nozzle opening ( 24 ). The nozzle ( 22 ) of each assembly ( 10 ) is displaceable relative to the substrate ( 16 ) for effecting ink ejection on demand. The nozzles ( 10 ) each have a respective actuator unit ( 28 ) connected to the nozzle ( 22 ) and arranged externally of the chamber ( 34 ) for controlling displacement of the nozzle ( 22 ).
1. An inkjet printhead comprising:
a supporting substrate for mounting in a printer; and,
a plurality of nozzle assemblies, each nozzle assembly having a nozzle defining a nozzle opening, the nozzle being configured to hold ink adjacent the nozzle opening, and an actuator for moving the nozzle relative to the supporting substrate to eject ink through the nozzle opening.
2. An inkjet printhead according to claim 1 wherein the nozzle assemblies each further comprise a nozzle chamber for holding ink adjacent the nozzle opening, the nozzle chambers being partially formed from the nozzles and each of the actuators being connected to the substrate and the nozzle in the respective nozzle assembly.
3. An inkjet printhead according to claim 2 wherein the nozzle assembly further comprises an arm connecting each of the actuators to the nozzles of their respective nozzle assemblies such that the nozzle is cantilevered over the supporting substrate by the actuator.
4. An inkjet printhead according to claim 3 wherein CMOS drive circuitry is deposited under the nozzle chamber and the actuators using planar monolithic deposition, lithographic and etching processes.
5. An inkjet printhead according to claim 1 wherein the actuator is a thermal bend actuator.
6. An inkjet printhead according to claim 5 wherein the actuator has at least two beams, one being an active beam and the other being a passive beam.
7. An inkjet printhead according to claim 1 wherein the nozzle has a wall section to telescopically engage a complementary wall section in the nozzle chamber extending from the substrate such that the actuator can displace the nozzle portion toward the substrate.
8. An inkjet printhead according to claim 7 wherein the telescopic engagement is a sliding fit between the wall section of the nozzle portion and the complementary wall section is toleranced to inhibit leakage from the nozzle chamber having regard to the surface tension of the ink.