A light incident into a wedge type light scattering conducting element from a light incident surface of the light scattering conducting element is converted into a light flux having a directionality and is output from a light output surface. The output light is input to a wedge type emitting direction...http://www.google.es/patents/US6152570?utm_source=gb-gplus-sharePatente US6152570 - Surface light source device
