Thermal ink jet printhead with suspended heater element spaced from chamber walls

摘要

There is disclosed an ink jet printhead that has a plurality of nozzles 3 and a bubble forming chamber 7 corresponding to each nozzle 3 . The bubble forming chamber of each nozzle having at least one side wall 6 and at least one heater element 10 suspended within each of the bubble forming chambers respectively. 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 heater element 10 spaced from the at least one side wall 6 of the bubble forming chamber 7 . The spacing between the heater element 10 and the at least one side wall 6 is between 0.1 microns and 20 microns. The nucleation and growth of a gas bubble causes the pressure pulse that ejects ink from the nozzle aperture. By laterally enclosing the bubble with at least one of the side walls of the chamber, most of the pressure can be dissipated by ejecting ink through the nozzle.