A new nonimpact printing technique for alphanumeric characters

A simple, new electrolytic printing method for alphanumeric characters is described. The paper employed may be an ordinary cellulose paper that is locally sensitized by means of a suitable wetting device that distributes the recording solution onto the paper just before recording. The wetting mechanism of the paper has been fully examined by taking into account the effects of evaporation and the paper capillarity. The action of the gravitational field on the deposited liquid film has been also examined. The semifluid friction mechanism that allows the very high sliding speed of the wetting device onto the paper has been also examined. A closer examination of all these phenomena has guided the practical realization of a suitable wetting device. This wetting device can be employed in conjunction with a printing head constituted in a preferential form by a vertical row of a given number of pairs of electrodes, each electrode of the pair being on a line in the direction of the printing head travel. In this way, good spot definition is obtained even at very high printing speed, provided that the electrolytic recording solution satisfies some conditions. The problem of the electrical interaction between switched pairs of electrodes has been fully examined, and suitable means for obtaining constant color intensity have been described. We have shown that the general problem of the formulation of the electrolytic recording solution may be handled in a remarkable way by using the electrochemical equilibrium diagrams. In a similar way one can treat the related problem of the corrosion of inert electrodes after very long runs. Finally, different kinds of printing heads have been described.