the present invention relates to the fields of illuminated signs and displays , and to decorative and specialist lighting fixtures . a light transmissive device includes a panel having a cavity for housing a light source , the panel having surfaces such that light emitted from a light source in the cavity propagating along the panel will be substantially totally internally reflected . the invention provides a construction that allows for a slim lighting panel with an innovative feature in the form of an illuminated edge at the sides of the light transmissive device , of any colour , thus providing a display device with a high visual impact .