Method for two stage engraving of printing cylinders employs video camera for registering engraving tools in second engraving step

摘要

After the first engraving as a start reference point for the axial and angular positions of the cylinder, a cup (21/1) is selected the as the surface center point (39) which occupies that position (GSPx,GSPy). When the cylinder is reinstalled for the final engraving an image taken by a video camera located at an axial reference position (38) indicates any axial and/or angular displacement (AxM, AyM) of the cup. These are compensated by repositioning the engraving tool or rotating the cylinder respectively .