Until now, light boxes, i.e. illumination apparatuses which are usually closed on all sides and are provided for emitting flat light, for example for backlighting information signs or advertisement panels, have usually been illuminated with neon and fluorescent lamps as light sources. There are different types of illumination for light boxes, comprising backlighting on one side, backlighting on two sides or lateral illumination (for example from the left and/or right and/or bottom and/or top) by laterally injecting light into the air space in the light boxes. The lateral illumination can include in particular illumination from one to four sides. For mounting purposes, these lamps are spanned by the associated light box and can typically illuminate panes of glass, panes of acrylic glass and banners, which are combined on the front with a specially printed advertisement sheet. In order to mount the neon and fluorescent lamps, said lamps are fastened on frame outer walls using a lampholder system. Alternatively, light can also be injected laterally into a light box. In this case, the light sources (sometimes with a reflector system) are fastened laterally in the frames of the light box. These light sources inject the light from the outside into the air space in the direction of a box center. The frames and rear walls of the poster boxes are usually painted matt white in order to distribute the light uniformly and homogeneously and to couple the light out forwards.
LED modules are also known as light sources, wherein the LED modules are fastened, for example screwed, individually to the frames or to a rear wall of the light box.