We have used Acoustic Ink Printing (AIP) to produce photographic quality prints using aqueous based inks on special coated papers. In AIP, an ultrasonic beam is focused on the free surface of the ink to eject discreet droplets of controlled diameter. This “nozzleless” process enables generation of extremely small drops without sensitivity to small defects in nozzle geometry because the drop size is determined by the lateral dimensions of the acoustic beam. We have used 1.5 pl drops and produced images at a quality level approaching standard silver halide processes. The printing is done at a spatial addressability of 600 spots per inch and the printed spot size can be varied by firing from 0 to 10 drops per pixel to achieve multiple gray levels at high resolution. The printheads were fabricated using thin-film processes along with specially developed mechanical assembly techniques. Printheads with 1024 ejectors were built at a nozzle density of 600 per inch to enable printing of a 1.7-inch-wide swath, operating at a drop ejection rate of 25 kHz. Several novel techniques were demonstrated to seamlessly stitch multiple swaths without degrading image quality or print speed.
R. Sprague, B. Hadimioglu, C. Brown, S. Buhler, R. Ellson, S. Elrod, R. Kowalski, D. Mantell, R. Matusiak, J. Roy, D. Ruiz, B. Russo, M. Weisberg, D. White, M. Young, J. Zesch, "Acoustic Ink Printing: Photographic Quality Printing At High Speed" in Proc. IS&T Int'l Conf. on Digital Printing Technologies (NIP17), 2001, pp 660 - 663, https://doi.org/10.2352/ISSN.2169-4451.2001.17.1.art00050_2