Inkjet nozzle device configured for venting gas bubbles
An inkjet nozzle device configured for venting a gas bubble during droplet ejection. The inkjet nozzle device includes: a firing chamber for containing ink, the firing chamber having a floor and a roof defining a nozzle aperture having a perimeter; and a heater element bonded to the floor of the firing chamber. The device is configured to satisfy the relationships A=swept volume/area of heater element=8 to 14 microns; and B=firing chamber volume/swept volume=2 to 6. The swept volume is defined as the volume of a shape defined by a projection from the perimeter of the nozzle aperture to the floor of the firing chamber, and includes a volume contained within the nozzle aperture.
1. An inkjet nozzle device configured for venting a gas bubble during droplet ejection, the inkjet nozzle device comprising:
a firing chamber for containing ink, the firing chamber having a floor and a roof defining a nozzle aperture having a perimeter; and
a heater element bonded to the floor of the firing chamber,
wherein the device is configured to satisfy the relationships A and B:
A =swept volume/area of heater element=8 to 14 microns
B =firing chamber volume/swept volume=2 to 6
wherein the swept volume is defined as the volume of a shape defined by a projection from the perimeter of the nozzle aperture to the floor of the firing chamber, the swept volume including a volume contained within the nozzle aperture.
2. The inkjet nozzle device of claim 1 , wherein the device is configured to eject ink droplets having a volume of from 75% to 100% of the swept volume.
3. The inkjet nozzle device of claim 1 , wherein the nozzle aperture is elliptical and the shape is an elliptic cylinder.
4. The inkjet nozzle device of claim 1 , wherein the heater element extends beyond opposite edges of the nozzle aperture.
5. The inkjet nozzle device of claim 1 , wherein the heater element extends substantially between first and second walls of the firing chamber.
6. The inkjet nozzle device of claim 5 , wherein a centroid of the heater element is equidistant from the first and second walls.
7. The inkjet nozzle device of claim 5 , wherein the first wall is an end wall of the firing chamber and the second wall is a baffle wall, and wherein a pair of chamber inlets are defined on either side of the baffle wall.
8. The inkjet nozzle device of claim 7 , wherein the baffle wall is wider than the heater element.
9. The inkjet nozzle device of claim 1 , wherein the roof has a thickness in the range of 1 to 5 microns.
10. The inkjet nozzle device of claim 1 , wherein the firing chamber has a height in the range of 5 to 20 microns.
11. The inkjet nozzle device of claim 1 , wherein the firing chamber has a volume in the range of 4 to 15 pL.
12. The inkjet nozzle device of claim 1 , wherein the swept volume is in the range of 1 to 5 pL.
13. The inkjet nozzle device of claim 1 , wherein the heater element is absent a cavitation protection layer.