Thermal ink-jet printhead with an optimized fluid flow channel impedance

摘要

A thermal ink-jet ejector (10) having a fluid flow channel (12) extending between an ink inlet (16) and a nozzle (18) for the ejection of liquid ink therefrom, includes a rear channel diffuser (30) disposed between the heating element (20) and the inlet (16), and/or a front channel diffuser (32) disposed between the heating element (20) and the nozzle (16). Each diffuser (30, 32) includes an arrangement of tapers which decrease the flow impedance of liquid ink flowing toward the nozzle (18), and increase the flow impedance of liquid ink flowing toward the inlet (16). The arrangement increases the kinetic energy of droplets being ejected, and also increases the speed of re-fill of the channel with liquid ink following ejection. IMAGE