Volume measurement of inkjet droplets

摘要

Obtaining good quality printouts using an inkjet print head depends on good jetting performance. Besides dropletformation and velocity, droplet volume is a critical factor for characterizing this performance. The purpose of thisproject is the development of an optical method for measuring the volume of single droplets in flight, as well ascomplementary analysis of statistical data such as droplet volume distribution for the Ricoh Gen5 print head with rowspacing of 0.55mm. Waveform designs, unique for each ink and temperature combination, can be improved using thistechnique. For these reasons, an optical system, using three cameras with varying focal points, was developed to obtainthree-dimensional information about droplets in flight. Evaluation of resultant data showed that the chosen method iscapable of measuring single droplet volumes within a range of 15%, irrespective of position. Thus, the method isshown to be practicable, and can be integrated into existing drop watchers to allow for the analysis of droplet volumewhen designing waveforms.