US Patent 7309882 Surface light source with photonic crystal LED

A backlight system (20) includes a light guide plate (220), a reflector (230) disposed below the light guide plate, and an LED (210) emitting light beams into the light guide plate. The LED includes an LED chip (213), which has a base (2131), a film layer (2132), a protecting layer (2133), and an organic layer (2134) sequentially stamped on a first electrode (212) from bottom to top. The LED chip further has an optical crystal structure including a plurality of micro-holes (2135) which run through the film layer, the protecting layer and the organic layer.