Illuminating device for dial indicator

For an arrangement to illuminate a display device with a dial face (1), whereby the rear side of the dial face (1) is opaque over its entire surface with the exception of a transmissive area (2) and whereby this transmissive area (2) serves to form a scale, it is proposed to provide a reflector shell (3) on the rear side of the dial face (1), the shape of which is such that the light emitted by a light-emitting diode (4) against a reflector wall (5) is diffusely distributed over the transmissive area (2) of the dial face (1).