While the trend for high resolution, photo quality printing demands inkjet drop volumes of a few picoliters, there are other applications that require large drop volumes for low resolution, high optical density printing. By modification of standard Xaar-type piezo inkjet printheads ink drops of more than 150 pl volume could be produced. Controlled drop formation was obtained, channel starvation did not occur, and the printhead appeared robust against misfiring, so that no channels were lost when printing even odd pattern for extended times.In a further development step each ink channel was equipped with four nozzles, arranged in a square. In this fashion ,square dots’ were printed, which perfectly filled the square pixels of a 185 dpi raster. Consequently high quality line pattern could be printed on several inkjet papers at optical densities larger than 2 in a single pass.
W. Zapka, R. Kaack, W. Voit, M. Schulz, M. Zimmermann, L. Levin, W. Ahlemeier, "Large Drop Volumes From Xaar-Type Inkjet Printheads" in Proc. IS&T Int'l Conf. on Digital Printing Technologies (NIP18), 2002, pp 161 - 165, https://doi.org/10.2352/ISSN.2169-4451.2002.18.1.art00040_1