Ink jet nozzle arrangement incorporating mechanically coupled bend actuator arms
View Patent ↗An ink jet nozzle arrangement is provided for ejecting ink. The ink jet nozzle arrangement includes a substrate that defines an ink inlet. Integrated circuitry is positioned on the substrate. A nozzle structure is positioned on the substrate and defines a nozzle chamber in fluid communication with the ink inlet and an ink ejection port in fluid communication with the nozzle chamber from which ink can be ejected. An elongate actuator has a fixed end fast with respect to the substrate and a free end extending into the nozzle chamber. The actuator includes a pair of mechanically coupled and electrically isolated arms extending along the substrate with one of the arms being interposed between the other arm and the substrate. The interposed arm is electrically coupled to the integrated circuitry. Responsive to receiving an electrical signal from the integrated circuitry, the actuator bends so as to induce movement of its free end and thereby ejects ink in the nozzle chamber from the ink ejection port.
1. An ink jet nozzle arrangement for ejecting ink, the ink jet nozzle arrangement comprising:
a substrate that defines an ink inlet;
integrated circuitry positioned on the substrate;
a nozzle structure positioned on the substrate and defining a nozzle chamber in fluid communication with the ink inlet and an ink ejection port in fluid communication with the nozzle chamber from which ink can be ejected; and
an elongate actuator having a fixed end fast with respect to the substrate and a free end extending into the nozzle chamber, the actuator comprising a pair of mechanically coupled and electrically isolated arms extending along the substrate with one of the arms being interposed between the other arm and the substrate, the interposed arm being electrically coupled to the integrated circuitry;
wherein the actuator is configured so that when the interposed arm receives an electrical signal from the integrated circuitry, the actuator experiences differential thermal expansion and bends to induce movement of its free end and thereby eject ink in the nozzle chamber from the ink ejection port.
2. An ink jet nozzle arrangement as claimed in claim 1 , wherein the arms are mechanically coupled by a plurality of struts fast between the arms.
3. An ink jet nozzle arrangement as claimed in claim 1 , wherein the interposed arm is formed from a titanium-aluminium-nitride (TiAl)N deposit.
4. An ink jet nozzle arrangement as claimed in claim 1 , wherein the electrical signal is a pulsed signal.
5. An ink jet nozzle arrangement as claimed in claim 1 , wherein the free end of the actuator terminates in a paddle.
6. An ink jet nozzle arrangement as claimed in claim 1 , further comprising a movement sensor for determining the degree or rate of pivotal movement of the actuator.
7. An ink jet nozzle arrangement as claimed in claim 1 , wherein the fixed end of the actuator is fast with the substrate via a support that extends from the substrate.
8. An ink jet nozzle arrangement as claimed in claim 1 , wherein the substrate comprises a silicon layer.