Nozzle guard for an ink jet printhead
View Patent ↗A nozzle guard ( 80 ) for an ink jet printhead includes a body member ( 82 ) mountable on a substrate ( 16 ) which carries a nozzle array ( 14 ). The body member defines a plurality of passages ( 84 ) through it such that, in use, each passage ( 84 ) is in register with a nozzle opening of one of the nozzles of the array ( 14 ). The body member ( 22 ) further defines fluid inlet openings ( 88 ) for directing fluid through the passages ( 84 ), from an inlet end of the passages ( 84 ), for inhibiting the build up of foreign particles on the nozzle ( 14 ).
1. A printhead for an ink jet printer, the printhead including:
an array of nozzles and respective colorant ejection means for ejecting colorant onto a media substrate to be printed; and,
a nozzle guard positioned to inhibit damaging contact with the exterior of the array of nozzles;
said nozzle guard having a body member covering the exterior of the nozzles and a support means for supporting the body member on the printhead,
said body member having an array of passages in registration with the array of nozzles so as not to impede the normal trajectory of the colorant ejected from each nozzle;
said nozzle guard including fluid inlet openings for directing fluid through said passages, to inhibit the build up of foreign particles on the nozzle array; wherein:
said fluid is passed continuously through said passages at a velocity that is less than the velocity of the ejected colorant.
2. A printhead according to claim 1 wherein the body member is formed from silicon.
3. A printhead according to claim 1 wherein the support means is integrally formed from the body member, the support means comprising a pair of spaced support elements one being arranged at each end of the body member.
4. A printhead according to claim 3 wherein the fluid inlet openings are arranged in one of the support elements.
5. A printhead according to claim 4 wherein the fluid inlet openings are arranged in the support element remote from a bond pad of the nozzle array.
6. A printhead according to claim 1 wherein colorant is ejected at a velocity of 3 m/s.
7. A printhead according to claim 1 wherein the fluid is passed through the passages at 1 m/s.