PRINTING ORIGINAL PLATE FORMING METHOD

摘要

PURPOSE:To omit a printing silver salt film and to produce electrically and simply a photosensitive resin plate by partially removing a light reflecting layer by discharge braekdown and exposing and developing the photosensitive resin layer by light passing the removed part. CONSTITUTION:The light reflecting layer 1 to be a mask sheet for a printing plate is supported by a transparent base material 2 and the photosensitive resin layer 3 is supported by a base material 4. The base material 2 is tightly superposed to the reflecting layer 1 recording a required pattern and light 7 radiated from a chemical lamp is projected from the reflecting layer 1 side to form an unexposed part 5 and an exposed part 6 on the fitted resin layer 3. The resin layer 3 is developed by a washing solution 8 to wash out the unexposed part 5 and left exposed part 6 on the base material 4. Consequently, a printing silver salt film to be used for the production of a printing plate can be omitted and the resin plate can be electrically and simply produced.