Fog development using a formative surface

• Main Author: Biegelsen, David K
• Format: Patent
• Language: English
• Published: 17.10.2023
• Subjects: COLOUR PRINTING; CORRECTION OF TYPOGRAPHICAL ERRORS; i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; LINING MACHINES; MATERIALS FOR SURFACES USED IN PRINTING MACHINES FOR PRINTING,INKING, DAMPING, OR THE LIKE; PERFORMING OPERATIONS; PREPARING SUCH SURFACES FOR USE AND CONSERVING THEM; PRINTING; PRINTING MACHINES OR PRESSES; PRINTING PLATES OR FOILS; PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; PROCESSES FOR THE MANUFACTURE OR REPRODUCTION OF PRINTINGSURFACES; SELECTIVE PRINTING MECHANISMS; STAMPS; TRANSPORTING; TYPEWRITERS

A formative surface having a conductive base covered with a dielectric and oleophobic/hydrophobic surface layer is created with defined pits to grow micro-puddles of a defined volume. The formative surface is brought into close proximity with a charge retentive surface carrying a charge image. Fountain solution vapor nucleates and grows preferentially on the base of the pits as micro-puddle droplets. The puddles are charged and extracted from the surface to provide a fog of charged droplets of narrow volume and charge distribution. The charged droplets are attracted and repelled respectively from the charged and discharged image regions of the charge retentive surface, thus developing the charged image into a fountain solution latent image. The developed latent image is then brought into contact with a transfer member blanket and split, thus creating on the blanket a fountain solution latent image ready for inking.