Ink ejection devices within an inkjet printer

摘要

A printer has a plurality of ink ejection devices, each device comprising a substrate that incorporates drive circuitry and defines a fluid inlet channel; a nozzle chamber structure that is positioned on the substrate and defines a nozzle chamber in fluid communication with the fluid inlet channel and a fluid ejection port in fluid communication with the nozzle chamber; a micro-electromechanical actuator that is positioned on the substrate and is electrically connected to the drive circuitry to be displaced relative to the substrate on receipt of an electrical current from the drive circuitry; a fluid ejecting member that is positioned in the nozzle chamber and is connected to the actuator to eject fluid from the ink ejection port on displacement of the actuator; and a covering formation that is positioned on the substrate and is configured to enclose the micro-electromechanical actuator.