Inkjet printhead having nozzle guard with formations for proper alignment

1. An inkjet printer including a printhead including:

an array of nozzles for ejecting ink onto media to be printed; and

alignment formations configured for engagement with complementary formations on an apertured nozzle guard having an array of ink apertures corresponding to the array of nozzles; wherein;

engagement between the alignment formations and the complementary formations holds the apertures in registration with the nozzles such that the guard does not obstruct the normal trajectory of ink ejected from the nozzles onto the media.

2. A printer according to claim 1 wherein each of the nozzles in the array is individually aligned with one of the ink apertures in the nozzles guard.

3. A printer according to claim 1 wherein the array of nozzles is formed on a silicon substrate incorporating the alignment formations.

4. A printer according to claim 3 wherein the nozzle guard has a shield containing the array of ink apertures, the shield being spaced from the silicon substrate by integrally formed struts extending from the shield for engagement with the alignment formations.

5. A printer according to claim 3 wherein the alignment formations are spaced ridges on the silicon substrate positioned to slidingly engage the sides of the struts to maintain the apertures in alignment with the nozzle array.

6. A printer according to claim 4 wherein the alignment formations are recesses in the substrate positioned to slidingly engage the sides of the struts to maintain the nozzle guard in alignment with the nozzle array.

7. A printer according to claim 4 wherein integrally formed struts extend from the silicon substrate to engage ridges or recesses formed in the nozzles guard.

8. A printer according to claim 1 wherein the alignment formations are formed during the production of the array of nozzles.

9. A printer according to claim 1 wherein the nozzle guard is formed from silicon.

10. An inkjet printer including a printhead assembly, the printhead assembly including:

a printhead having an array of nozzles for ejecting ink onto media to be printed; and,

an apertured nozzle guard having an array of ink apertures corresponding to the array of nozzles;

the printhead further including alignment formations interengaged with complementary formations on the apertured nozzle guard to hold the apertures in registration with the nozzles such that the guard does not obstruct the normal trajectory of ink ejected from the nozzles onto the media.

11. A printer assembly according to claim 10 wherein each of the nozzles in the array is individually aligned with one of the ink apertures in the nozzles guard.

12. A printer according to claim 10 wherein the array of nozzles is formed on a silicon substrate incorporating the alignment formations.

13. A printer assembly according to claim 12 wherein the nozzle guard has a shield containing the array of ink apertures, the shield being spaced from the silicon substrate by integrally formed struts extending from the shield for engagement with the alignment formations.

14. A printer assembly according to claim 13 wherein the alignment formations are spaced ridges on the silicon substrate positioned to slidingly engage the sides of the struts to maintain the apertures in alignment with the nozzle array.

15. A printer assembly according to claim 13 wherein the alignment formations are recesses in the substrate positioned to slidingly engage the sides of the struts to maintain the nozzle guard in alignment with the nozzle array.

16. A printer assembly according to claim 12 wherein integrally formed struts extend from the silicon substrate to engage ridges or recesses formed in the nozzles guard.

17. A printer assembly according to claim 10 wherein the alignment formations are formed during the production of the array of nozzles.

18. A printer according to claim 10 wherein the nozzle guard is formed from silicon.