Liquid-projection method and device for high-resolution printing in a continuous ink-jet printer

摘要

In a liquid projection method and a high-resolution printing device in a vibrationally excited continuous ink-jet printer, an ink jet is divided into drops in the vicinity of a charging device for the electrostatic charging of these drops creating an electrical field that is asymmetrical with respect to the axis of the jet. The method comprises a first step of creating a single microdrop at the upstream end of a main drop by the application of a charging voltage V.sub.M higher than the Rayleigh voltage to the charging device when this main drop appears. Then a second step of deflecting the microdrop to be used for the printing by the application, to the following main drop, of a charging voltage V.sub. c, lower than the voltage V.sub.M and lower than the Rayleigh voltage, that can be modulated as a function of the path chosen for the microdrop towards the printing medium. The charging device can take the form of two half-planes intersecting each other in a direction parallel to the axis of the ink jet.