| 摘要 |
PURPOSE:To shorten the processing time of the title device by previously dividing a work into sections which require laser scanning and those which do not require laser scanning and increasing the speed of the laser scanning on the sections which do not require laser scanning. CONSTITUTION:At the time of making a 1m<2> plate, individual picture data and data indicating the effective extents of the picture data are contained in a picture storage section 70. A central arithmetic section 60 makes judgment based on the picture data and the data indicating the effective extents of the picture data stored in the storage device 70 and raster scanning is performed on the extent bounded by the dotted lines of a work 30 at an actual platemaking speed. At the time of the raster scanning, the rotating speed of a drum 40 is increased in the main scanning direction and moved in parallel with the auxiliary scanning axial direction in the auxiliary scanning direction outside the bounded area, so that the raster scanning on unnecessary parts can be prevented as much as possible. Thus the entire processing time can be reduced. |
