Patent ID: 9744619
Date: 2017-08-29
CPC Classifications: B23K,B29C,B29K,B29L,B41C,G03F

Claim:
1. An apparatus for laser engraving of printing plates or sleeves, the apparatus comprising: a laser source having sufficient power output to directly engrave an elastomeric printing plate or sleeve positioned on an imaging drum of a drum imager or on a flat bed of a flatbed imager, the drum of the drum imager being rotatable around a longitudinal axis, and having a longitudinal direction defined by the axis of rotation and a transverse direction defined along the circumference of the drum, the flatbed imager having a longitudinal direction and a transverse direction perpendicular to the longitudinal direction, the plate having an outer surface and an elastomeric body, the laser source when in operation emitting an incident laser beam; a set of one or more beam splitters operative to split the incident laser beam into a plurality of split beams; a plurality optical-beam modulators operative to simultaneously modulate the plurality of split beams, each respective optical-beam modulator controlled according to a respective portion of imaging data, to create one or more modulated beams from each split beam; a focusing subsystem for each split beam operative to focus the one or more modulated beams created from the split beam onto the printing plate; wherein a drive mechanism included in the drum imager or flatbed imager is operative to provide relative motion between the focused modulated beams and the plate in the transverse and longitudinal directions for modulating according to the respective portions of imaging data, wherein each focusing subsystem has a focal length and each focused modulated beam has a focal spot having a focal spot size on the outer surface of the plate, corresponding to being focused to a respective depth level in the plate, wherein at least two focusing subsystems have different focal lengths such that the focal spot sizes on the outer surface differ, and such that the outer surface of the printing plate is simultaneously engraved by a plurality of modulated beams of different respective focal spot sizes on the outer surface, and wherein the focal spots of the focused modulated beams build a row along the axial direction of the printing plate.