Abstract: A cold light UV irradiation device is used for curing UV paint and UV printing dyes on heat-sensitive substrates (12,13). It is used, for example, in plants for printing on packaging foils or in the production line for CD□s (Compact Discs) and DVD□s (Digital Versatile Discs). The irradiation devices used until now emit in addition to the UV radiation also a high portion of heat radiation (IR Radiation) onto the substrate (12,13), which often leads to deformation and brittleness of the substrate. The present invention allows an effective separation of the UV radiation from the IR radiation. With short beam paths, a high UV intensity with a low heat load of the substrate is realized.