Inkjet printhead having high areal inkjet nozzle density
View Patent ↗An inkjet print head is provided having a nozzle areal density of at least 40000 inkjet nozzles per square centimeter on a printing surface. Each nozzle has an ink chamber on the printing surface having an ink ejection port, and a heater for heating the ink in the chamber to cause ink ejection from the ink ejection port.
1. An inkjet printhead having a nozzle areal density of at least 40000 inkjet nozzles per square centimeter on a printing surface, each nozzle comprising:
an ink chamber on the printing surface having an ink ejection port; and
a heater for heating the ink in the chamber to cause ink ejection from the ink ejection port,
wherein each heater has an annular shape.
2. A print head according to claim 1 , wherein each heater is configured to heat the ink so as to form a vapor bubble therein which increases pressure in the respective chamber thereby causing said ink ejection.
3. A print head according to claim 2 , wherein each heater has beams suspended from side walls of the respective chamber.
4. A print head according to claim 3 , wherein the beams of each heater are configured so that a point of collapse of the vapor bubble is therebetween.
5. A print head according to claim 3 , wherein the side walls of each chamber depend from the printing surface so as to support a plate in which the respective ink ejection port is defined.
6. A print head according to claim 1 , wherein the annular shape of each heater is configured so that a point of collapse of the vapor bubble is in a centre thereof.
7. A print head according to claim 1 configured as a page width inkjet print head.