METHOD OF ACTINICALLY IMAGING

摘要

A lithographic printing plate or other coated imageable substrate is imaged by heating an area of the coating with an infrared laser and reacting the coating in the heated area with ultraviolet or visible radiation. The coating can be either positive working or negative working. The modulated radiation may either be the ultraviolet/visible radiation or the infrared radiation and the radiation spots are superimposed or the ultraviolet/visible spot may closely trail the infrared spot. The imaging time is reduced since the reaction rate is increased at the elevated temperature.