Nonlinear piezo-inkjet equivalent circuit modeling for predicting ink ejection velocity fluctuation caused by meniscus oscillation

This study used an equivalent circuit model to collectively analyze the oscillation phenomena inside a piezo-inkjet printhead as an electrical oscillation. We propose a new equivalent circuit model that can accurately predict fluctuations in the ink ejection velocity due to meniscus oscillation. Our experimental results for the dependency of the ink ejection velocity on the pulse width of the input waveform included a nonlinear effect having no fixed period. Our new model uses a nonlinear acoustic resistance characterized by the sum of a square function and sine function. The new equivalent circuit model was incorporated into the LTspice behavioral modeling calculations. A good match was observed between the experimental results for the inkjet ejection velocity and results calculated by the model.