Concept for LED wedge backlight without color control

LED arrays have wider color co-ordinates and are more easily recycled than fluorescent backlights, but the control of color from each LED is difficult and expensive. Wedge light-guides mix the emissions of adjacent LED's, but conventional designs do not mix thoroughly enough to remove the need for color control. We propose a design which allows rays to fan-out to the width of the screen before they enter the wedge-shaped region. This fan-out region is folded behind the wedge-shaped region so that light from any one LED illuminates the whole screen uniformly. Each part of the screen is designed to be illuminated equally by all the LED's so there is no need for color control.