The present disclosure relates to a backlight for illuminating back lit displays (e.g. LC displays of LCD televisions). In order to enable a thin design of the backlight and a high uniformity of the light emitted by the backlight, an apparatus may be provided with transparent and diffusing masking elements that may mask individual light sources and may diffuse light back into a light guide. Absorbing elements and/or retro-reflective elements may be arranged proximate the light sources in order to avoid generation of bright spots or rings around the light sources.
