This disclosure provides systems, methods and apparatus related to an illumination system for a display device. In one aspect, the illumination system includes a light guide having a view region, which directly overlies display elements of a display, and a ledge region between the view region and a light source that injects light into the light guide. The ledge region is coated with an at least partially non-transmissive layer. The layer can be at least partially absorptive and/or at least partially reflective. In some implementations, the layer can include microstructures configured to turn steep-angle light such that it is redirected across the light guide at a shallower angle. In some implementations, the boundary between the ledge region and the view region of the light guide can have a nonlinear shape.