Firing chamber geometry for inkjet printhead

摘要

A firing chamber (36) configuration for the drop ejectors of inkjet printheads extends the life of the heat transducer (34) by ensuring that bubble collapse (and attendant cavitation) occurs at a location well spaced from the heat transducer. The sidewalls (62) of the firing chamber are shaped relative to the firing chamber entry (44) in a manner such that a strong jet of inflow ink is provided for moving the collapsing vapor bubble from the center of the chamber and against a curved back wall (60) of the firing chamber. In one preferred embodiment, the refill ink impinges on the back wall, divides, and is redirected away from the back wall toward pockets (66) defined in chamber. The pockets are remote from the heat transducer. As a result, the refill ink urges the collapsing (bifurcated) bubble into the pockets where final collapse occurs away from the heat transducer. <IMAGE>