US Patent 7140743 Direct backlight module

A direct backlight module has a light guide plate, a plurality of lamp tubes, a reflecting plate and a frame. The light guide plate has a upper surface and a lower surface, and at least one surface of the light guide plate is coated with an ink layer. The lamp tubes are located below the light guide plate. The reflection plate is located below the lamp tubes. The frame covers the reflecting plate, lamp tubes and light guide plate. The ink layer contains a plurality of diffusing granules for diffusing lights to produce uniform lights.