Nozzle assembly for a printhead arrangement with gutter formations to prevent nozzle contamination
View Patent ↗A printhead arrangement for a printer, the arrangement having a plurality of nozzle assemblies formed on a wafer substrate by means of micro-electromechanical (MEMS) techniques. Each assembly includes an ink chamber with at least one ink supply channel etched into the substrate, and a heater element suspended in the ink chamber. Each assembly also includes drive circuitry for driving said heater element, and a nozzle plate defining two ink ejection nozzles. The nozzle plate has gutter formations about each nozzle to collect ink run-off.
1. A printhead arrangement for a printer, the arrangement comprising
a wafer substrate defining at least one ink supply channel; and
a plurality of nozzle assemblies formed on a wafer substrate as a result of micro-electromechanical (MEMS) techniques, each assembly comprising:
an ink chamber in fluid communication with said at least one ink supply channel;
a heater element suspended in the ink chamber;
drive circuitry arranged on the wafer substrate for driving said heater element; and
a nozzle plate defining at least two ink ejection nozzles, the plate having gutter formations to collect ink run-off from the nozzle.
2. The printhead arrangement of claim 1 , wherein a bubble trap is positioned in the ink chamber and includes a bubble trap having a bubble retention structure, a vent being formed in the nozzle plate.
3. The printhead arrangement of claim 2 , wherein the bubble retention structure includes a series of columns spaced around a periphery of the ink supply channel, said columns configured to direct gas bubbles in ink to the vent where they vent to atmosphere.
4. The printhead arrangement of claim 1 , wherein a filter structure is positioned in the ink chamber in the form of rows of obstructions extending transverse to the flow direction through the ink supply, each row being spaced such that the obstructions of respective rows are out of registration with each other with respect to the flow direction.
5. The printhead arrangement of claim 1 , wherein the drive circuitry includes CMOS driving circuitry.
6. The printhead arrangement of claim 1 , wherein each nozzle assembly includes priming features extending into the ink supply channel so that an ink meniscus is inhibited from pinning itself to a peripheral edge of the ink supply.
7. The printhead arrangement of claim 1 , wherein the heater element is an elongate suspended beam of TiAlN.