Patent ID: 7284484

Claim:
Apparatus for reducing variations in at least one of total indicated run-out and taper in a printing roller having an external surface with a radius, comprising: a detector which scans across and around at least a portion of the printing roller corresponding to where printing occurs and detects variations in the radius of the scanned portions of the printing roller during relative movement between the detector and the roller prior to any laser ablation of the surface of the printing roller in order to determine the radius at all scanned portions of the external surface of the printing roller and which produces an output corresponding thereto; a laser which ablates said surface of the printing roller; and a controller which, in response to the output from the detector: a) processes the output of the detector to determine different portions of the external surface of the printing roller to be ablated by said laser so as to reduce said at least one of total indicated run-out and taper of the printing roller, b) controls the position at which the printing roller is ablated, and c) controls the laser to ablate each portion of the printing roller that is determined to be ablated by said laser so as to reduce said at least one of total indicated run-out and taper of the printing roller.