Droplet deviation modeling and compensation scheme of inkjet printing

Abstract

The depositing quality accomplished by inkjet printing process is significantly affected by droplet positioning accuracy which plays an essential role in formation performance and printing efficiency. However, the droplet deviation induced by various factors is rarely studied specifically because most researchers mainly concentrate on the dynamics and mechanics of droplet and ink-substrate interaction to enhance the printing precision. In fact, among all the contributing factors to droplet deviation, the relative motion between nozzle and substrate tends to cause the ejected droplet to deflect from its desired position and the deviation is inevitable as long as the existence of horizontal velocity. The error brought about by this phenomenon is commonly negligible in the majority of current studies with the assumption of slow relative horizontal speed between nozzle and substrate. But it is not always acceptable to keep a quite low horizontal translation speed which would result in inefficiency of printing. In order to satisfy the demanding requirements in efficiency and accuracy of inkjet printing, some strategies are proposed to mitigate the droplet deviation out of the above phenomenon in this paper. An adaptive approach to nozzle feedrate control with a look-ahead algorithm is presented in this paper to compensate the errors by means of reconstructing the tool paths with deviation prediction in advance based on the feedrate profile and the geometrical characteristics of tool paths. The error model is established with full consideration of different circumstances influenced by droplet deviation and is subsequently integrated into the control process of the nozzle feedrate. The practical implementation demonstrates the effectiveness and feasibility of the proposed method.