Display device including reflective layers and light conversion layer on bottom of LED reflective layer on top of LED

Patent metadata

Field	Value
Publication number	US-12094919-B2
Application number	US-202117534190-A
Country	US
Kind code	B2
Filing date	Nov 23, 2021
Priority date	Dec 8, 2020
Publication date	Sep 17, 2024
Grant date	Sep 17, 2024

Abstract

A display device includes a substrate on which a plurality of sub-pixels are disposed, a first reflective layer disposed on the substrate, a plurality of LEDs disposed in each of the plurality of sub-pixels on the first reflective layer, a plurality of light conversion layers disposed between the first reflective layer and the plurality of LEDs, and a plurality of second reflective layers covering at least a portion of the plurality of LEDs. Light emitted from the plurality of LEDs is reflected by the plurality of second reflective layers, and light having a wavelength longer than that of the light emitted from the plurality of LEDs is emitted upwardly from the plurality of LEDs.

First claim

What is claimed is:

1. A display device, comprising:
a substrate on which a plurality of sub-pixels is disposed;
a first reflective layer disposed on the substrate;
a plurality of LEDs disposed in each of the plurality of sub-pixels on the first reflective layer;
a plurality of light conversion layers disposed between the first reflective layer and the plurality of LEDs; and
a plurality of second reflective layers covering at least a portion of the plurality of LEDs,
wherein light emitted from the plurality of LEDs is reflected by the plurality of second reflective layers, and light having a wavelength longer than that of the light emitted from the plurality of LEDs is emitted upwardly from the plurality of LEDs.

2. The display device of claim 1 , wherein the plurality of sub-pixels includes:
a red sub-pixel displaying red light;
a green sub-pixel displaying green light; and
a blue sub-pixel displaying blue light,
wherein the plurality of LEDs are blue LEDs.

3. The display device of claim 2 , wherein the plurality of light conversion layers includes:
a red light conversion layer disposed in the red sub-pixel; and
a green light conversion layer disposed in the green sub-pixel.

4. The display device of claim 2 , wherein the plurality of light conversion layers is disposed in the red sub-pixel and the green sub-pixel,
wherein the plurality of second reflective layers is disposed in the red sub-pixel and the green sub-pixel.

5. The display device of claim 1 , wherein the first reflective layer reflects the light from the plurality of LEDs toward the plurality of light conversion layers,
wherein light that is converted in the plurality of light conversion layers passes through the plurality of second reflective layers and
wherein the plurality of second reflective layers reflects the light emitted from the plurality of LEDs toward the first reflective layer.

6. The display device of claim 1 , further comprising:
a plurality of insulating layers covering the plurality of respective light conversion layers between the plurality of LEDs and the plurality of light conversion layers,
wherein the plurality of insulating layers is spaced apart from each other.

7. The display device of claim 6 , wherein a refractive index of the plurality of insulating layers is higher than a refractive index of a region between the plurality of insulating layers.

8. The display device of claim 1 , wherein each of the plurality of LEDs includes:
a first semiconductor layer;
a light emitting layer disposed on the first semiconductor layer; and
a second semiconductor layer disposed on the light emitting layer.

9. The display device of claim 8 , wherein the plurality of LEDs further includes:
a plurality of first electrodes electrically connected to the first semiconductor layers of the plurality of LEDs; and
a plurality of second electrodes electrically connected to the second semiconductor layers of the plurality of LEDs,
wherein each of the plurality of first electrodes is electrically connected to the first electrode adjacent thereto in a first direction,
wherein each of the plurality of second electrodes is electrically connected to the second electrode adjacent thereto in a second direction different from the first direction.

10. The display device of claim 8 , further comprising:
a transistors electrically connected to the plurality of respective LEDs.

11. A display device, comprising:
a substrate:
a first reflective layer disposed on the substrate;
a plurality of light conversion layers disposed on the first reflective layer;
a plurality of blue LEDs disposed on the plurality of light conversion layers; and
a plurality of second reflective layers disposed to cover at least a portion of the plurality of blue LEDs,
wherein the plurality of second reflective layers reflects blue light emitted from the plurality of blue LEDs toward the plurality of light conversion layers and transmit light from the plurality of light conversion layers.

12. The display device of claim 11 , wherein the plurality of light conversion layers includes:
a red light conversion layer overlapping one part of the plurality of blue LEDs; and
a green light conversion layer overlapping another part of the plurality of blue LEDs.

13. The display device of claim 12 , wherein the plurality of second reflective layers overlaps the red light conversion layer and the green light conversion layer.

14. The display device of claim 12 , wherein the plurality of light conversion layers and the plurality of second reflective layers do not overlap a remaining blue LED of the plurality of blue LEDs.

15. The display device of claim 11 , wherein the first reflective layer is formed of an opaque metallic material,
wherein the second reflective layer is a distributed Bragg reflector (DBR).

16. The display device of claim 11 , further comprising:
a plurality of insulating layers surrounding upper surfaces and side surfaces of the plurality of respective light conversion layers between the plurality of light conversion layers and the plurality of blue LEDs,
wherein the plurality of insulating layers planarize upper portions of the plurality of light conversion layers.

Assignees

• Lg Display Co Ltd

Inventors

• Kim Wonrae
• Lee Seungbum
• Kim Younghoon
• Yang Yoonsik

Classifications

• H10W90/00 Primary

  Package configurations · CPC title

• H10D86/40

  characterised by multiple TFTs · CPC title

• H10H20/856

  Reflecting means · CPC title

• H10H20/851

  Wavelength conversion means · CPC title

• H10H20/812

  within the light-emitting regions, e.g. having quantum confinement structures · CPC title