<p>The device has a sheet or ribbon-shaped print substrate (B) conveyed through a printer, and a dryer (11) with an emitter device that is assigned to a conveying path of the print substrate. An adjusting device (14) for adjusting permeability of radiation and/or light is arranged at the emitter device in path of the radiation that is directed to functional units of the printer and discharged from the emitter device.</p>
