| 摘要 |
PURPOSE:To realize a mask forming method by which a mask having excellent positional accuracy is easily obtained without fail in the case of forming the mask formed at a retouch stage in a printing plate making stage. CONSTITUTION:This method is the mask forming method for forming the mask on a transparent film B positioned in a state where it is superposed on an original A. For example, by performing positioning in such a state that the original A where the image is formed and the transparent film B are superposed, receiving transmitted light or reflected light from the original A obtained by irradiating the original and comparing received image position information with area information separately stored, a mask area on the original A is judged and the mask for shielding the unnecessary part of the original from light is formed on the transparent film B while detecting the image position of the original A. |
