The authors developed the novel ink-jet technology using electrostatic force. One of the features of this technology is that the minute ink droplets are ejected from a large aperture. This results in fewer clogging problems than conventional ink-jet technologies. More than 2000 dpi resolution can be achieved with this technology. The dot-size can be modulated by pulse-width modulation. Furthermore, the authors observed the concentration effect of the ink when it is ejected. The essence of this technology is to eject charged ink droplets by electrostatic force. The ink contains positively or negatively charged colorants which disperse in a highly resistive solvent, and are supplied from an ink tank to the tip of an injection needle. The injection needle with an inner diameter of more than 500 μm is the ink-jet electrode. When the signal and bias voltage with the same polarity as that of the colorants is applied to the injection needle, a small meniscus is formed at the tip position. And the charged ink droplets are ejected onto the paper by the electrostatic force between the injection needle and the recording media (paper).In this paper the features of the novel ink-jet technology, experimental setup, observation results, and the printing samples are described.
Teruo Murakami, Shuzo Hirahara, Hitoshi Nagato, Yuko Nomura, "High Definition Ink-Jet Printing: 10-20μm Dots Eject from an Injection Needle" in Proc. IS&T Int'l Conf. on Digital Printing Technologies (NIP14), 1998, pp 36 - 39, https://doi.org/10.2352/ISSN.2169-4451.1998.14.1.art00009_1