LED backlighting system
View Patent ↗A liquid crystal display (LCD) device having non-white and white light emitting diodes and a liquid crystal display. A spectrum converting material is positioned between non-white LEDs and the LCD to convert the non-white light from the LEDs toward a white light spectrum. The liquid crystal display may include a plurality of light emitting diodes, a light pipe, and a spectrum converting material. The spectrum converting material may be a phosphorized material located between the plurality of non-white light emitting diodes and the light pipe. A light extracting surface may be located near a first surface of the light pipe, a diffuser located near a second side of the light pipe, where the first and second sides are opposite sides of the light pipe, a reflective polarizer, and an liquid crystal display. The light from the light pipe may passes through the diffuser, the reflective polarizer, before backlighting the liquid crystal display. The non-white LEDs may include blue LED, ultraviolet LEDs, and the like.
1. A liquid crystal display (LCD) device, comprising:
a white light emitting diode;
a light pipe;
a light extracting surface located near a first side al the light pipe;
a diffuser located near a second side of the light pipe, where the first and second sides are opposite sides of the light pipe;
a reflective polarizer;
a liquid crystal display;
a first polarization scrambling material located along the light pipe opposite the liquid crystal display;
a second polarization scrambling material between the white light emitting diode and the light pipe; and
wherein light from the white light emitting diode enters the light pipe and passes through the diffuser, the reflective polarizer, then backlights the liquid crystal display.
2. The LCD device of claim 1 , wherein the white light emitting diode is located along a perimeter of a circuit board.
3. The LCD device of claim 2 , wherein the circuit board comprises a flexible circuit board.
4. The LCD device of claim 2 , further comprising a thermally conductive material between the circuit board and a frame.
5. The LCD device of claim 2 , wherein the white light emitting diode has a top reflective orientation with the light pipe.
6. The LCD device of claim 2 , wherein the white light emitting diode has a side reflective orientation with the light pipe.
7. The LCD device of claim 1 , wherein the second polarization scrambling material forms apertures near the white light emitting diode.
8. The LCD device of claim 1 , wherein the first polarization scrambling material comprises an enhanced diffuser reflector.
9. The LCD device of claim 1 , further comprising an enhanced specular reflector disposed near the white light emitting diode and the light pipe, where light form the white light emitting diode reflects from the enhanced specular reflector into the light pipe.