Actuating Voltage Waveform Optimization of Piezoelectric Inkjet Printhead for Suppression of Residual Vibrations

Abstract

After a piezoelectric inkjet printhead jets the first droplet, the actuating membrane still vibrates, creating residual vibrations in the ink channel, which can degrade the inkjet printhead performance. For suppressing these vibrations, an optimized actuating voltage waveform with two pulses must be obtained, of which the first pulse is used for jetting and the second pulse is used to suppress the residual vibrations. In this study, the pressure history within the ink channel of a recirculating piezoelectric inkjet printhead was first acquired using lumped element modeling. Then, for suppressing residual vibrations, a bipolar voltage waveform was optimized via analysis of the tuning time (tt
 ), dwell time (td2), rising time (tr2), falling time (tf2), and voltage amplitude of the second pulse. Two voltage waveforms, Waveform 01 and Waveform 02, were optimized thereafter. In Waveform 01, tt=2 μs, td2=2 μs, and tr2 and tf2=1 μs
 were finalized as the optimal parameters; in the case of another waveform, the optimal parameters of td2, tr2, and tf2 were found to be 4, 1, and 1 μs, respectively. The optimal voltage amplitude of the second pulse was found to be 1/3 the amplitude of the first pulse. On the basis of our analysis, the tuning time in Waveform 01 is the most sensitive parameter, and the performance yielded is even poorer than that yielded by standard waveform, if not optimized. Therefore, the other waveform is recommended for the suppression of residual vibrations.

A Simple Method for Fabricating Ink Chamber of Inkjet Printheads

“…However, the formation of satellites is typically an unwanted feature of inkjet printing technology [ 36 , 37 ]. Liu et al reported that the threshold for satellite formation is a function of Z and the practical range for ink printability is approximately bound by 2 < Z < 20 [ 38 ].…”

Classifications and Applications of Inkjet Printing Technology: A Review

“…The ink chamber still undergoes pressure oscillations even after the first ink droplet has been ejected under an applied standard voltage waveform using the pull-push actuation mechanism [24]. These undesired pressure oscillations decay after several microseconds, cause variations in the properties of the subsequent ink drops, and form satellites, which degrades the inkjet printhead performance.…”

The design of an inkjet drive waveform using machine learning

“…The design of a multipulse waveform has recently been presented as a means of reducing the length of ligament or satellite drops 24 . Hur’s team utilized the lumped element model of a recirculating piezoelectric inkjet printhead to improve bipolar waveforms, demonstrating that a bipolar waveform with a second pulse voltage of 1/3 than that of the first could suppress residual vibrations within the printhead channel 25 . Despite the development in waveform design methodologies, the knowledge of wave propagation and drop formation is limited, and waveform optimization still requires time-consuming and repetitive waveform parameter modifications, while monitoring obtained jetting images.…”