A light emitting device including a drive transistor that generates a drive current IDR of a current amount corresponding to a gate-source voltage IDR, a light emitting element that emits light at a luminance corresponding to the current amount of the drive current, and a control unit that controls the gate-source voltage according to a specified gradation is configured as follows. The tower includes a plurality of interlocking modules and is mounted on a two perpendicularly aligned skids. Each of the punch pins is for insertion through one of the holes defined in the upper member and one of the holes defined in the lower member. The video signal processor additionally includes a frame buffer coupled to the prescaler. The further layer consists in particular of a very thin, strong paper impregnated with acrylate. This store provides a consumer with access, via said distributor, to items assigned that unique tag.