TREATMENT OF PHOTOSENSITIVE LITHOGRAPHIC PRINTING PLATE

摘要

PURPOSE:To maintain the specified liquid activity of a developing soln. by changing a prescribed level and/or the amt. of the developing replenisher corresponding to the prescribed level with the increase in the treating amt. of a PS plate. CONSTITUTION:The prescribed leven and/or the amt. of the developing replenisher corresponding to the prescribed level is changed with an increase in the treating amt. of the photosensitive lithographic printing plate. A more preferable sensor is exemplified by an electrical sensor provided in the mid-way of a developing zone in order to measure the degree of deterioration of the developing soln. in terms of the elution degree of the non-image part of the PS plate. The elution degree of the non-image part of the PS plate is preferably measured as an impedance by the electrical sensor. The sensor in this case has more preferably 0.1mm-15cm distance between the one electrode of the sensor and the other electrode. The distance between the PS plate and the electrode is preferably <=5mm. The area of the electrodes in the part where the PS plate and the electrodes are lined up in parallel is preferably 2-10cm<2>.