An apparatus comprises a display backlight having a substrate and a plurality of light-receiving channels formed in that substrate. At least some of these channels have a depth that varies as a gradient along a longitudinal axis of the channel that is substantially axially aligned with a light-receiving input for the channel. These channels can be formed substantially parallel to one another. The aforementioned light-receiving inputs can, if desired, be formed at either end of each such channel and can be disposed inwardly of an edge of the substrate. Also if desired, at least some of these channels can be disposed other than at an orthogonal angle with respect to such substrate edges. So configured, light rays that orthogonally enter the light-receiving inputs will have an opportunity to contact the edges of the channels and be reflected outwardly of the channel to provide the desired backlighting effect.