Nozzle device with movement sensor
View Patent ↗A nozzle device is provided for an inkjet printhead. The nozzle device includes a substrate assembly defining an ink supply. A chamber-defining layer defines a nozzle chamber in fluid communication with a nozzle opening and the ink supply. An actuating arm is coupled to the substrate assembly and terminates in a paddle separating the ink supply and nozzle chamber. The actuating arm is configured to pivot during actuation so that the paddle moves and causes ink within the nozzle chamber to be ejected out through the nozzle opening. A movement sensor is configured to determine the degree or rate of pivotal movement of the actuating arm.
1. A nozzle device for an inkjet printhead, the nozzle device comprising:
a substrate assembly defining an ink supply;
a chamber-defining layer defining a nozzle chamber in fluid communication with a nozzle opening and the ink supply;
an actuating arm coupled to the substrate assembly and terminating in a paddle separating the ink supply and nozzle chamber, the actuating arm configured to pivot during actuation so that the paddle moves and causes ink within the nozzle chamber to be ejected out through the nozzle opening; and
a movement sensor configured to determine the degree or rate of pivotal movement of the actuating arm.
2. A nozzle device as claimed in claim 1 , wherein the movement sensor comprises:
a moving contact element formed integrally with the actuating arm; and
a fixed contact element formed integrally with the substrate assembly and positioned to be contacted by the moving contact element when the actuating arm pivots to a predetermined extent.
3. A nozzle device as claimed in claim 1 , wherein the actuating arm includes a thermal bend portion proximal to the substrate assembly, an active portion of the thermal bend portion being connected electrically to a current source within the substrate assembly.
4. A nozzle device as claimed in claim 3 , wherein the electrical connection is made to end terminals of the actuating arm, and the current source is configured to apply pulsed excitation voltage to said terminals.
5. A nozzle device as claimed in claim 3 , wherein a passive portion of the thermal bend portion is mechanically coupled to but electrically isolated from the active portion by posts with no current-induced heating occurring within the passive portion, the active portion being located between the passive portion and the substrate assembly.