Thermal ink jet printhead with bubble formation surrounding heater element

摘要

There is disclosed an ink jet printhead that has a plurality of nozzles unit cells 1 and one or more heater elements 10 corresponding to each nozzle 3 . Each heater element 10 is configured to heat a bubble forming 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 an ejectable liquid (such as ink) through an ejection aperture 5 in each nozzle 3 , to effect printing. The gas bubble encircles at least some of the heater element. By configuring the heater element such that the bubbles formed surround the element, the heat transfer to the bubble forming liquid is maximized. Less heat is wasted through conduction to the surrounding nozzle structures thereby raising the overall efficiency of the printhead.