This paper aims to present an optimization method of the input driving signal of a piezoelectric inkjet printhead to improve droplet consistency and increase jetting frequency.
The optimization target is the transient pressure in the nozzle caused by the input driving signal, which directly generates the droplets. After demonstrating the linearity of the driving input and system pressure, an analytic model as a transfer function was developed, allowing calculation of the pressure vibration in the nozzle for an arbitrary input. Different patterns of input signal were parameterized and applied into the optimizing function, which represents the difference between the ideal and the actual pressure vibration. By determining the function minimum, the optimized parameters of the input signal were estimated.
Optimization results of different input patterns were compared and verified by the numerical model of the printhead, and it was revealed that the optimization method that combined the quenching pulse and an increased falling time interval was more effective than use of a single method.
After the process of optimization, a new type of input signal to the piezoelectric inkjet printhead was showed. By this method, the frequency of the printhead could be increased without losing consistency of droplets.
