Patent ID: 7851134

Claim:
A method for producing a structure of photo-polymerization picture points in the light-sensitive layer of printing plates as an image of picture data composed from a matrix of picture points, by way of structured exposure with a light source, wherein each photo-polymerization picture point is produced by an individual exposure sequence selected in dependence on the one hand on the surface density of the photo-polymerization picture points to be set at a location of the photo-polymerization picture point, and on the other hand on the picture data, wherein at non-set picture points which are located at locations with medium surface density, non-printing photo-polymerization subsurface points are produced with a preliminary exposure sequence comprising the following step: exposure with a preliminary exposure dose, for bonding oxygen contained in the light-sensitive layer, wherein the preliminary exposure dose is selected such that photo-polymerization is still not yet effected, and wherein at set picture points at locations with medium or large surface density, printing photo-polymerization picture points are produced with a standard sequence, comprising the following steps: a. exposure with the mentioned preliminary exposure dose; b. exposure with a structure intensification dose, wherein the structure intensification dose is selected such that together with the preliminary exposure dose, it produces a condition in which the light-sensitive layer is essentially no longer water-soluble, but yet still adheres on a subsurface of the printing plate; and c. exposure with a standard dose, wherein the standard dose is selected such that together with the preliminary exposure dose and the structure intensification dose at locations with the greatest surface density, it effects a complete photo-polymerization of the photo-polymerization picture point; and wherein no exposure is effected at non-set picture points which are located at locations with a large surface density.