A Low-Cost Flash Photographic System for Visualization of Droplets in Drop-on-Demand Inkjet

Flash photography has been widely used to study the droplet dynamics in drop-on-demand (DoD) inkjet due to its distinct advantages in cost and image quality. However, the whole setup, typically comprising the mounting platform, flash light source, inkjet system, CCD camera, magnification lens and pulse generator, still costs tens of thousands of dollars. To reduce the cost of visualization for DoD inkjet droplets, we proposed to replace the expensive professional pulse generator with a low-cost microcontroller board in the flash photographic system. The temporal accuracy of the microcontroller was measured by an oscilloscope. The microcontroller's temporal stability was compared with a professional pulse generator by tracking a large number of droplet positions. To validate the effectiveness of the whole setup, the droplet ejection and the droplet impact on a silicon wafer were quantitatively analyzed and compared with theoretical predictions. Finally, sample images of droplet ejected from a commercial inkjet cartridge were presented to show the flexibility of the system. (C) 2018 Society for Imaging Science and Technology.