Printhead with drive transistors and corresponding ink ejection actuators

摘要

A printhead for ejecting ink includes a substrate defining a plurality of ink supply channels. A plurality of nozzles is operatively mounted to the substrate. Each nozzle defines a respective ink chamber in fluid communication with a respective ink supply channel and an aperture through which ink can be ejected. A plurality of elongate actuators each have a thermally actuated arm with one end fixed to the substrate and a free end extending into a respective ink chamber. Each actuator configured to move on receipt of an electrical signal to eject ink from the ink chamber through its corresponding aperture. Each arm has a heater element. A drive circuitry layer is positioned on the substrate. The drive circuitry layer includes a plurality of drive transistors connected to the heater elements of corresponding respective actuators. The drive transistors are interposed between their associated actuators and the substrate.