Patent ID: 7399575

Claim:
A relief printing original plate, comprising: a substrate; a photosensitive layer that is laminated on said substrate and that is photosensitive to ultraviolet radiations; and a mask layer that is laminated on the photosensitive layer, said mask layer having an ability to absorb both an ultraviolet radiation and infrared radiation, the ultraviolet absorbability of said mask layer being deactivatable in response to receiving said infrared radiation, wherein said mask layer comprises a binder resin, an acid generator, and an ultraviolet absorber whose ability to absorb the ultraviolet radiations is deactivatable in response to contact with an acid, and wherein the deactivation of the ultraviolet absorbability in response to receiving said infrared radiation takes place along with ablation of the mask layer when radiation energy of the infrared radiation is higher than a predetermined value.