US Patent 7144132 Two-sided illuminated panel with uniform illumination

A two-sided illuminated panel, comprising a first diffuser and a second diffuser arranged so as to face each other and adapted to form internally at least one chamber, the chamber being closed laterally, one or more light sources being supported laterally, and further comprising at least one partition arranged diagonally within the chamber and adapted to equalize the light emitted by the one or more light sources onto the first and second diffusers.