Abstract: An illuminating device for illuminating a background surface of a surface display has a frame with inner reflecting surfaces. A circuit board with leads closes off the interior of the frame. The circuit board is made of a light-transmissive material and serves as the background surface to be illuminated. The circuit board comprises leads and light-emitting diode chips connected to the leads so as to be controllable. A scattering body in the form of a light-transmissive potting compound containing scattering centers is filled into the interior of the frame. The circuit board is preferably a circuit board with a cover layer of a non-light-transmissive material from which the coating of non-light-transmissive material has been removed by etching. The scattering centers are preferably in the form of glass particles.