Fluid ejection device with drop volume modulation capabilities

Abstract

A method of controlling ink drop volume in an inkjet printhead includes the steps of providing a piezoelectric module. The module has a plate with an integrated ink chamber in flow communication with an integrated ink supply manifold and an integrated ink orifice. The ink chamber includes a main channel that connects the ink supply manifold to the ink orifice, and multiple piezoelectric actuators depending from the main channel and spaced apart by ink subchannels in flow communication with the main channel that define an array of piezoelectric actuators. A ground electrode is in contact with a first end of each of the actuators, and a cover plate is bonded to the piezoelectric plate to seal the chamber and the manifold. The cover plate is in contact with a control electrode and is configured to conduct control signals from the control electrode to the actuators. The method includes selectively activating one or more piezoelectric actuators in the array of piezoelectric actuators to create a pressure wave that propagates through the ink supply and ejects an ink drop the volume of which is dependent on the number of actuators that are activated is also disclosed.