US Patent 7752792 Billboard with light emitting diode light source

A billboard (100) includes a light module (120) and a light-permeable panel (140). The light module comprises a plurality of elongated light conductors (122) and at least one LED (124). Each of the light conductors has two end surfaces (1222, 1224) and a circumferential lateral surface (1223) interconnected between the end surfaces, and one of the end surfaces of each of the light conductors is adjacent to and optically coupled to the at least one LED. The light-permeable panel has a light incident surface (142) and an opposite light emitting surface (144). One of the light incident surface and the light emitting surface has a pattern (143).