Patent ID: 7874249

Claim:
A lithographic printing plate deactivating device comprising: (a) a deactivating agent and a structure for providing said deactivating agent; (b) an exposed lithographic plate comprising a substrate and a photosensitive layer having exposed (hardened or solubilized) areas and non-exposed (non-hardened or non-solubilized) areas, the non-exposed areas being capable of hardening (for negative plate) or solubilization (for positive plate) under a room light before contacting with said deactivating agent, and becoming incapable of hardening or solubilization under said room light after contacting with said deactivating agent; and (c) a means for transporting said exposed lithographic plate through said structure to contact with said deactivating agent to deactivate without developing said exposed lithographic plate wherein said deactivating agent is an acidic aqueous solution with a pH of less than 4.0.