LED-based large area display

• US 8,994,056 B2
• Filed: 07/12/2013
• Issued: 03/31/2015
• Est. Priority Date: 07/13/2012
• Status: Active Grant

• Current Assignee: Intematix Corporation
• Original Assignee: Intematix Corporation
• Inventors: Edwards, Charles
• Primary Examiner(s): Lebentritt, Michael
• Application Number:
  US13/941,236
• Publication Number:
  US 20140014983A1
• Time in Patent Office: 627 Days
• Field of Search: 257/40, 257/89, 257/79, 257/98
• US Class Current: 257/98
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: G09F 9/33 being semiconductor devices, e.g. diodes
• CPC Class Codes: H01L 27/156 two-dimensional arrays
• CPC Class Codes: Y10S 977/774 Exhibiting three-dimensional carrier confinement, e.g. quantum dots
• CPC Class Codes: Y10S 977/95 Electromagnetic energy

Abstract

An improved approach is described to implement an LED-based large area display which uses an array of single color solid state lighting elements (e.g. LEDs). In some embodiments, the panel comprises an array of blue LEDs, where each pixel of the array comprises three blue LEDs. An overlay is placed over the array of blue LEDs, where the overlay comprises a printed array of phosphor portions. Each pixel on the PCB comprised of three blue LEDs is matched to a corresponding portion of the overlay having the printed phosphor portions. The printed phosphor portions of the overlay includes a number of regions of blue light excitable phosphor materials that are configured to convert, by a process of photoluminescence, blue excitation light generated by the light sources into green or red and colored light. Regions of the overlay associated with generating blue light comprise an aperture/window that allows blue light to pass through the overlay.

Claims

1. A display panel comprising:

an array of light emitting pixels comprising red, blue and green light emitting sub-pixels;

a pixel in the array of light emitting pixels comprising an array of three blue light emitting solid-state devices and a light transmissive overlay placed over the array of solid-state light emitters; and

wherein regions of the overlay corresponding to red light emitting sub-pixels comprise a red light emitting photoluminescence material, regions of the overlay corresponding to green light emitting sub-pixels comprise a green light emitting photoluminescence material and regions of the overlay corresponding to blue light emitting sub-pixels comprise a light transmissive region.

2. The display panel of claim 1, wherein the solid-state light emitters comprise light emitting diodes.

3. The display panel of claim 1, wherein the photoluminescence materials are selected from the group consisting of a phosphor material, quantum dots, and combinations thereof.

4. The display panel of claim 1, wherein the display panel comprises a large area display having a width or height of at least 4 feet.

5. The display panel of claim 1, further comprising a spacer located between the array of the three blue light emitting solid-state devices and the light transmissive overlay.

6. The display panel of claim 5, wherein the spacer implements a wall between light emitting devices for adjacent sub-pixels.

7. The display panel of claim 5, further comprising an optical medium within the spacer.

8. The display panel of claim 1, further comprising a common drive voltage or current to drive the array of the three blue light emitting solid-state devices.

9. The display panel of claim 1, wherein the light transmissive overlay comprises a gloss finish.

10. The display panel of claim 1, wherein the photoluminescence material is printed onto the overlay.

11. The display panel of claim 1, wherein the overlap comprises a diffuser material.

12. The display panel of claim 11, in which the diffuser material is located at the regions of the overlay corresponding to blue light.

13. The display panel of claim 11, wherein the diffuser material is selected from the group consisting of titanium dioxide (TiO₂), barium sulfate (BaSO₄), and magnesium oxide (MgO), silicon dioxide (SiO₂) or aluminum oxide (Al₂O₃).

14. The display panel of claim 1, wherein regions corresponding to different sub-pixel colors have different sizes, shapes, or dimensions.

15. The display panel of claim 14, wherein a green sub-pixel has a larger size than a red sub-pixel, and the red sub-pixel has a larger size than a blue sub-pixel.

16. The display panel of claim 1, wherein regions corresponding to the sub-pixel colors comprise a round or rectangular shape.

17. The display panel of claim 1, in which the array of light emitting pixels comprises an interlocking format for the pixels, wherein the pixels are shaped to fit the interlocking format.

18. The display panel of claim 17, wherein the pixels comprise an L-shape.

19. A display panel comprising:

an array of light emitting pixels comprising red, blue and green light emitting sub-pixels;

a pixel in the array of light emitting pixels comprising an array of three blue light emitting solid-state devices, a spacer, and a light transmissive overlay placed over the array of solid-state light emitters; and

wherein regions corresponding to red light emitting sub-pixels comprise a red light emitting photoluminescence material, regions corresponding to green light emitting sub-pixels comprise a green light emitting photoluminescence material and regions corresponding to blue light emitting sub-pixels comprise a light transmissive region.

20. The display panel of claim 19, wherein the photoluminescence material is included as fill material within the spacer.