Inkjet printhead with planar heater parallel to nozzle

摘要

There is disclosed an ink jet printhead which comprises a plurality of nozzles 3 and one or more heater elements 10 in a chamber 7 corresponding to each nozzle 3. Each heater element 10 is configured to heat a liquid 11 in the printhead to a temperature above its boiling point to form a gas bubble 12 therein. The generation of the bubble 12 causes the ejection of a drop 16 of the liquid (such as ink) through an ejection aperture 5 in each nozzle 3, to effect printing. The heater element is a beam suspended in the chamber for immersion in the liquid such that heating the liquid forms a gas bubble in order to eject a drop of the liquid through the nozzle. Laterally enclosing the heater element by the interior surface of the bubble forming chamber ensures that the nucleation and growth of the gas bubble directs the pressure pulse in the same direction as that of the ejected drop. If the bubble is not enclosed, much of the pressure dissipates sideways instead of through the nozzle with the ejected ink.