• Journal of the Korean Society for Precision Engineering
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• v.29 no.3
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• pp.295-301
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• 2012

The method for spraying of liquids through an electrical field has become a printing method since it can make very small droplet. For electro-hydrodynamic jet printing to become a reliable jetting tool, the jetting performance should be characterized with respect to various jetting conditions. To optimize jetting conditions, the jetting behavior should be measured. In this study, we present a visualization techniques to measure jetting behavior from electro-hydrodynamic (EHD) inkjet head. Unlike most previous method, we use the CCD camera to measure the jetting behavior. For this purpose, LED light is synchronized with jetting signal and sequential image was obtained by adjusting the delay time of the LED light. Finally, merits and demerits of using CCD camera were discussed to measure jetting image from EHD inkjet head.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.4
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• pp.449-454
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• 2012

The method for spraying of liquid through an electrical filed has become a printing method since it can make very small droplet. To increase the reliability using the electro-hydrodynamic (EHD) jet printing, the jetting status needs to be monitored. Vision measurement techniques using high speed camera has been used to visualize the jet images. However, it requires image processing of a lot of images after image acquisitions. So, it is difficult to understand jet behavior such as jetting frequency, jet repeatability etc. In this work, a low cost electrical current measurement method was developed to measure electrical current from EHD jet printing. To verify the jetting monitoring capability of developed circuit, images from high speed camera were processed for comparison purpose.