Device and method for electrographically printing or copying using liquid inks

A device for electrographic printing or copying, comprising:

• a latent image carrier having a potential pattern corresponding to an image pattern to be printed;
• an applicator element that carries a liquid layer of ink;
• an air gap between the liquid layer and a surface of the latent image carrier opposed thereto;
• droplets transferred from the liquid layer by overcoming the air gap being provided on the surface of the latent image carrier for inking a latent image on the latent image carrier to form an inked image;
• a force field in the air gap, said force field acting on the liquid layer;
• and
• a surface of the applicator element having a structure at which detachment of droplets from the liquid layer is facilitated, said structure comprising a plurality of first areas having an increased electrical conductivity, a plurality of second areas that differ from a remaining surface based on a portion of surface energy, and a plurality of third areas formed as elevations.

A device for electrographic multi-color printing or copying, comprising:

• a plurality of printing units each for a different color and each comprising a latent image carrier having a potential pattern corresponding to an image pattern to be printed, and an applicator element that carries a liquid layer of ink;
• an air gap between each applicator element liquid layer and a surface of each latent image carrier opposed thereto;
• an intermediate latent image carrier positioned to run through the air gaps associated with each of the printing units;
• at each printing unit, droplets transferred from the applicator liquid layer by overcoming the air gap being provided on the surface of the intermediate latent image carrier for inking a respective latent image on the intermediate carrier for each different color;
• a force field in each of the air gaps, said force field acting on the respective liquid layer;
• and
• a surface of each of the respective applicator elements having a structure at which detachment of droplets from the respective liquid layer is facilitated, said structure comprising a plurality of first areas having an increased electrical conductivity, a plurality of second areas that differ from a remaining surface based on a portion of surface energy, and a plurality of third areas formed as microscopic elevations.

A method for electrographic printing or copying, comprising the steps of:

• providing a latent image carrier having a potential pattern corresponding to an image pattern to be printed;
• providing an applicator element that carries a liquid layer of ink spaced from a surface of the latent image carrier by an air gap;
• providing a surface of the applicator element with a structure with which detachment of droplets from the liquid layer is facilitated, said structure comprising a plurality of first areas having an increased electrical conductivity, a plurality of second areas that differ from a remaining surface based on a portion of surface energy, and a plurality of third areas formed as microscopic elevations;
• applying a force field in the air gap to act on the liquid layer;
• and
• by overcoming the air gap, transferring droplets from the liquid layer on the surface of the latent image carrier for inking a latent image on the latent image carrier to create an inked image.

A method for electrographic printing or copying, comprising the steps of:

• providing a latent image carrier having a potential pattern corresponding to an image pattern to be printed;
• providing an applicator element that carries a liquid layer of ink spaced from a surface of the latent image carrier by an air gap;
• providing a surface of the applicator element with a structure at which detachment of droplets from the liquid layer is facilitated, said structure comprising a plurality of first areas having an increased electrical conductivity, a plurality of second areas that differ from a remaining surface based on at least one of a polar portion and a disperse portion of surface energy, and a plurality of third areas formed as microscopic elevations on an otherwise smooth surface of the applicator element;
• applying an alternating force field in the air gap to act on the liquid layer;
• and
• by overcoming the air gap, transferring droplets from the liquid layer on the surface of the latent image carrier for inking a latent image on the latent image carrier to create an inked image.

A method for multicolor electrographic printing or copying, comprising the steps of:

• providing a printing unit for each color comprising a latent image carrier having a potential pattern corresponding to an image pattern to be printed, and an applicator element spaced from a surface of the latent image carrier by an air gap and that carries a liquid layer of ink;
• on each different color applicator element, providing a surface having a structure at which detachment of droplets from the liquid layer is facilitated, said structure comprising a plurality of first areas having an increased electrical conductivity, a plurality of second areas that differ from a remaining surface based on a portion of surface energy, and a plurality of third areas formed as microscopic elevations;
• providing at each air gap a force field to act on the respective liquid layer;
• providing a moving intermediate carrier passing through the air gap at each printing unit;
• by overcoming the respective air gap, transferring droplets from each respective liquid layer of each applicator element onto a surface of the moving intermediate latent image carrier for inking a latent image on the intermediate latent image carrier;
• and
• transferring the latent images onto a final image carrier.