LED backlight system for LCD displays
View Patent ↗A LCD system including multiple light sources optically coupled through different light entry regions to at least one waveguide element positioned to backlight a LCD panel. A LCD system including multiple light sources coupled to light entry regions of two or more waveguides comprising a waveguide system positioned to backlight a LCD panel. Waveguides of various configurations and promoting even lighting of associated LCD panels are provided. Resulting LCD systems enable uniformly lit panels having diagonal measurements in excess of 12 to 14 inches, but the invention is not limited to panels of any particular size.
1. A liquid crystal display (LCD) system comprising:
a) a liquid crystal display panel comprising a viewing area;
b) at least one waveguide element comprising a plurality of light entry regions;
c) a first light-emitting source comprising a first plurality of LEDs, wherein the first plurality of LEDs is positioned to emit light into the at least one waveguide element at a first light entry region of the plurality of light entry regions, and wherein the first plurality of LEDs is arranged along at least one peripheral edge of the at least one waveguide element and outside the viewing area; and
d) a second light-emitting source comprising a second plurality of LEDs, wherein the second plurality of LEDs is positioned within the viewing area to emit direct backlight onto the liquid crystal display panel;
wherein the first light-emitting source and the second light-emitting source are arranged to light different regions of the liquid crystal display panel.
2. A liquid crystal display system according to claim 1 , wherein the at least one waveguide element comprises a plurality of waveguide elements, the first light-emitting source is positioned to emit light into at least one first light entry region of a first waveguide element of the plurality of waveguide elements, and the second light-emitting source is positioned to emit light into at least one second light entry region of a second waveguide element of the plurality of waveguide elements.
3. A liquid crystal display system according to claim 2 , wherein the first waveguide element is arranged to light a central or interior region of the liquid crystal display panel, and the second waveguide element arranged to light a peripheral or outer region of the liquid crystal display panel.
4. A liquid crystal display system according to claim 2 , wherein the first waveguide element and the second waveguide element are arranged in a layered configuration.
5. A liquid crystal display system according to claim 2 , wherein the first waveguide element and the second waveguide element abut one another laterally.
6. A liquid crystal display system according to claim 1 , wherein the first light entry region comprises at least one of a top edge of the at least one waveguide element, a bottom edge of the at least one waveguide element, a first side edge of the at least one waveguide element, and a second side edge of the at least one waveguide element.
7. A liquid crystal display system according to claim 1 , wherein any of the first light-emitting source and the second light-emitting source is embedded within a surface of the at least one waveguide element, or is optically coupled to at least one recess defined in a surface of the at least one waveguide element.
8. A liquid crystal display system according to claim 1 , further comprising a third light-emitting source positioned to emit direct backlight onto the liquid crystal display panel or to emit light into the at least one waveguide element.
9. A liquid crystal display system according to claim 1 , wherein the first plurality of light emitting diodes is arranged in a first strip, and the second plurality of light emitting diodes is arranged in a second strip.
10. A liquid crystal display system according to claim 9 , wherein at least one of the first strip and the second strip comprises a electrostatic discharge diode in electrical communication with the plurality of light emitting diodes arranged in the respective strip.
11. A liquid crystal display system according to claim 1 , wherein each of the first plurality of light emitting diodes and the second plurality of light emitting diodes comprises light emitting diodes adapted to emit wavelengths differing from one another.
12. A liquid crystal display system according to claim 1 , further comprising a common control circuit in electrical communication with the first light emitting source and the second light emitting source.
13. A liquid crystal display system according to claim 1 , wherein the at least one waveguide element defines at least one opening or gap, and the at least one opening or gap is positioned to allow passage of light from the at least a second light-emitting source for direct backlighting of the liquid crystal display panel without passage of said light through a material of any waveguide element of the at least one waveguide element.
14. A liquid crystal display system according to claim 1 , wherein the at least one waveguide element comprises multiple waveguide elements separated by at least one space, and the at least one space is positioned to allow passage of light from the at least a second light-emitting source for direct backlighting the liquid crystal display panel without passage of said light through a material of any waveguide element of the at least one waveguide element.
15. A liquid crystal display system according to claim 1 , wherein the at least one waveguide element consists of a single waveguide element comprising a unitary body structure.
16. A liquid crystal display system according to claim 2 , wherein the first waveguide element circumscribes at least a portion of the second waveguide element.
17. A liquid crystal display system according to claim 2 , wherein the first waveguide element circumscribes an entirety of the second waveguide element.