Compact inkjet nozzle device with high degree of symmetry

1. An inkjet nozzle device comprising an elongate main chamber having a floor, a roof and a perimeter wall extending between the floor and the roof, the perimeter wall having a pair of longer sidewalls and a pair of shorter endwalls, the main chamber comprising:

a firing chamber disposed towards one of the sidewalls, the firing chamber having a nozzle aperture defined in the roof and an elongate bar heater for ejection of ink through the nozzle aperture, the bar heater having a longitudinal axis;

an antechamber disposed towards an opposite sidewall for supplying ink to the firing chamber, the antechamber having first and second chamber inlets defined in the floor; and

an elongate baffle plate having a longitudinal axis extending parallel with the longitudinal axis of the bar heater, the baffle plate partitioning the main chamber to define the firing chamber and the antechamber,

wherein;

the inkjet nozzle device has mirror symmetry about a symmetry plane extending perpendicular to the longitudinal axes of the bar heater and the baffle plate;

the symmetry plane bisects the nozzle aperture, the bar heater and the baffle plate;

the first and second chamber inlets are positioned towards respective first and second opposite ends of the baffle plate; and

the first and second chamber inlets are equidistant from the symmetry plane.

2. The inkjet nozzle device of claim 1 , wherein the floor and the roof are common to the firing chamber and the antechamber.

3. The inkjet nozzle device of claim 1 , wherein each of the first and second chamber inlets has a higher capillary pressure than the nozzle aperture.

4. The inkjet nozzle of claim 3 , wherein each of the first and second chamber inlets has a smaller area than the nozzle aperture.

5. The inkjet nozzle device of claim 1 , wherein the baffle plate extends beyond the chamber inlet along a longitudinal axis of the inkjet nozzle device.

6. The inkjet nozzle device of claim 5 , wherein at least part of the chamber inlet extends beyond each end of the nozzle aperture along its major axis.

7. The inkjet nozzle device of claim 1 , wherein the nozzle aperture is elongate having a longitudinal axis perpendicular to the plane of symmetry.

8. The inkjet nozzle device of claim 1 , wherein the nozzle aperture is elliptical having a major axis parallel to the longitudinal axis of the bar heater and perpendicular symmetry plane.

9. The inkjet nozzle device of claim 8 , wherein the baffle plate has a length dimension greater than a length dimension of the nozzle aperture along its major axis.

10. The inkjet nozzle device of claim 1 , wherein the baffle plate has a length of at least 80% of a length of the bar heater.

11. The inkjet nozzle device of claim 1 , wherein a length of the bar heater is at least 70% of a total length of the inkjet nozzle device.

12. The inkjet nozzle device of claim 1 , wherein the perimeter wall and the baffle plate are comprised of a same material.

13. The inkjet nozzle device of claim 1 , wherein the firing chamber has a larger volume than the antechamber.

14. A print chip comprising at least one pair of nozzle rows, each nozzle row comprising a plurality of inkjet nozzle devices according to claim 1 , and wherein the nozzle apertures, baffle plates and bar heaters of said inkjet nozzle devices are co-aligned along a direction of each nozzle row.

15. A printhead comprising a plurality of print chips according to claim 14 .