In the project, we consider systems for the edge lighting of relatively small displays approximately 20 x 30 mm. Only one LED with nearly lambertian spatial distribution was used in the system. The optical system consisted of a wedge lightguide and a reflective surface, the surface can be either smooth or structured (with array of certain structure).
Various combinations of the wedge lightguides with the structured reflective surfaces were considered in the study, the designed variants were also compared to the systems with BEFs.
The designed systems provide acceptable illuminance uniformity for the central display zone, with small dark zones on the display margins. As a result of its simple construction and the ease with which it can be manufactured, the developed system, which has only one LED source, has potential applications in situations where the requirements for illuminance uniformity are not very high, for instance, in indicator devices.