Inkjet printhead having isolated nozzles
View Patent ↗A printhead suitable for minimizing cross-contamination between nozzles is provided. The printhead comprises a substrate, which includes a plurality of nozzles for ejecting ink droplets onto a print medium. Each nozzle has a nozzle aperture, which is defined in an ink ejection surface of the substrate. The printhead also comprises a plurality of formations on the ink ejection surface. The surface formations are configured to isolate each nozzle from at least one adjacent nozzle, and typically take the form of enclosures surrounding each nozzle.
1. A printhead comprising:
a substrate including a plurality of nozzles for ejecting ink droplets onto a print medium, each nozzle having a nozzle aperture defined in an ink ejection surface of the substrate; and
a plurality of formations on the ink ejection surface, the surface formations being configured to isolate each nozzle from at least one adjacent nozzle.
wherein the surface formations are configured in a plurality of nozzle enclosures, each nozzle enclosure comprising sidewalls surrounding a respective nozzle, the sidewalls forming a seal with the ink ejection surface, thereby isolating each nozzle from a least one adjacent nozzle.
2. The printhead of claim 1 , wherein the surface formations each have a hydrophobic surface.
3. The printhead of claim 1 , wherein each nozzle enclosure further comprises a roof spaced apart from the respective nozzle aperture, the roof having a roof opening aligned with its respective nozzle aperture, thereby allowing ejected ink droplets to pass therethrough onto the print medium.
4. The printhead of claim 3 , wherein the sidewalls extend from each roof to the ink ejection surface.
5. The printhead of claim 4 , wherein the sidewalls extend from a perimeter region of each roof.
6. The printhead of claim 1 , which is a pagewidth inkjet printhead.
7. The printhead of claim 1 , wherein the printhead has a nozzle density sufficient to print at up to 1600 dpi.
8. A printer comprising the printhead according to claim 1 .
9. A method of printing from the printhead of claim 1 , whilst minimizing cross-contamination of ink between adjacent nozzles, the method comprising the steps of:
(a) providing a printhead comprising:
a substrate including a plurality of nozzles for ejecting ink droplets onto a print medium, each nozzle having a nozzle aperture defined in an ink ejection surface of the substrate; and
a plurality of formations on the ink ejection surface, the surface formations being configured to isolate each nozzle from at least one adjacent nozzle; and
(b) printing onto a print medium using said printhead,
wherein the surface formations are configured in a plurality of nozzle enclosures, each nozzle enclosure comprising sidewalls surrounding a respective nozzle, the sidewalls forming a seal with the ink ejection surface, thereby isolating each nozzle from a least one adjacent nozzle.
10. A method of fabricating the printhead of claim 1 , having isolated nozzles, the method comprising the steps of:
(a) providing a substrate, the substrate including a plurality of nozzles for ejecting ink droplets onto a print medium, each nozzle having a nozzle aperture defined in an ink ejection surface of the substrate;
(b) depositing a layer of photoresist over the ink ejection surface;
(c) defining recesses in the photoresist, each recess revealing a portion of the ink ejection surface surrounding a respective nozzle aperture;
(d) depositing a roof material over the photoresist and into the recesses;
(e) etching the roof material to define a nozzle enclosure around each nozzle aperture, each nozzle enclosure having an opening defined in a roof and sidewalls extending from the roof to the ink ejection surface; and
(f) removing the photoresist,
wherein said sidewalls surround a respective nozzle, the sidewalls forming a seal with the ink ejection surface, thereby isolating each nozzle from at least one adjacent nozzle.