Radiation absorbing element for increasing color gamut of quantum dot based display devices

Patent metadata

Field	Value
Publication number	US-11320577-B2
Application number	US-201715788346-A
Country	US
Kind code	B2
Filing date	Oct 19, 2017
Priority date	Oct 31, 2016
Publication date	May 3, 2022
Grant date	May 3, 2022

Abstract

Embodiments of a display device are described. The display device includes a backlight unit having a light source, a quantum dot film, and a radiation absorbing element. The quantum dot film is optically coupled to the light source and is configured to process light received from the light source. The radiation absorbing element is optically coupled to the quantum dot film and is configured to tune a spectral emission width of the processed light received from the quantum dot film to achieve over 90% color gamut coverage of a standard RGB color space.

First claim

What is claimed is:

1. A backlight unit (BLU) of a display device, the BLU comprising:
a light source;
a quantum dot film, optically coupled to the light source, configured to absorb light from the light source and emit a processed light; and
a radiation absorbing element optically coupled to the quantum dot film, wherein the radiation absorbing element comprises nanostructured materials that exhibit optical absorption properties and do not exhibit optical emission properties and wherein the radiation absorbing element is configured to tune a spectral emission width of the processed light received from the quantum dot film to output over 90% color gamut coverage of an RGB color space with less than 10% decrease in brightness level of the processed light.

2. The BLU of claim 1 , wherein the RGB color space has chromaticity coordinates (0.56, 0.52), (0.06, 0.59), and (0.16, 0.13) for red, green, and blue primary colors.

3. The BLU of claim 2 , wherein the radiation absorbing element is configured to absorb a wavelength or a range of wavelengths from the processed light to output over 90% color gamut coverage of the RGB color space.

4. The BLU of claim 1 , wherein the radiation absorbing element comprises non-phosphor based material.

5. The BLU of claim 1 , wherein:
the quantum dot film comprises a matrix and barrier coated quantum dots disposed within the matrix; and
the radiation absorbing element is disposed within the matrix.

6. The BLU of claim 1 , wherein the radiation absorbing element comprises narrow band organic dye.

7. The BLU of claim 1 , further comprising an optical cavity; and
wherein the radiation absorbing element is disposed on a top surface of the optical cavity and the light from the light source is emitted out of the optical cavity through the top surface.

8. The BLU of claim 1 , wherein the radiation absorbing element comprises:
a first material having a first absorption property; and
a second material having a second absorption property different from the first absorption property.

9. The BLU of claim 1 , wherein the radiation absorbing element comprises:
a first material configured to absorb a first wavelength of the processed light; and
a second material configured to absorb a second wavelength of the processed light, the second wavelength being different from the first wavelength.

10. The BLU of claim 1 , wherein the radiation absorbing element is disposed on a substrate that is disposed on the quantum dot film.

11. The BLU of claim 1 , further comprising a light guide plate; and
wherein the radiation absorbing element is disposed on a top surface of the light guide plate and the light from the light source is emitted out of the light guide plate through the top surface.

12. The BLU of claim 1 , further comprising a reflector; and
wherein the radiation absorbing element is disposed on a surface of the reflector.

13. The BLU of claim 1 , wherein the quantum dot film comprises a plurality of quantum dots configured to emit red light.

14. The BLU of claim 1 , wherein the quantum dot film comprises a plurality of quantum dots configured to emit green light.

15. The BLU of claim 1 , wherein the quantum dot film comprises:
a first plurality of quantum dots configured to emit red light; and
a second plurality of quantum dots configured to emit green light.

16. The BLU of claim 1 , wherein the quantum dot film comprises:
a core-shell structure; and
a barrier layer surrounding the core-shell structure.

17. A display device comprising:
a backlight unit (BLU) comprising:
an optical cavity having a top side, a bottom side, and side walls, wherein light from a light source is emitted out of the optical cavity through the top side,
an array of light sources coupled to the optical cavity, and
a quantum dot film, positioned within the optical cavity, configured to absorb light from the array of light sources and emit a processed light; and
a radiation absorbing element positioned within the optical cavity, wherein the radiation absorbing element comprises nanostructured materials that exhibit optical absorption properties and do not exhibit optical emission properties and wherein the radiation absorbing element is configured to tune a spectral emission width of the processed light received from the quantum dot film to output over 90% color gamut coverage of an RGB color space with less than 10% decrease in brightness level of the processed light; and

an image generating unit (IGU) coupled to the BLU, wherein the BLU is configured to transit the processed light to the IGU.

18. The display device of claim 17 , wherein:
the quantum dot film comprises a matrix; and
the radiation absorbing element is embedded in the matrix.

19. The display device of claim 17 , wherein the radiation absorbing element comprises:
a first material configured to absorb a first wavelength of the processed light; and
a second material configured to absorb a second wavelength of the processed light, the second wavelength being different from the first wavelength.

Assignees

• Nanosys Inc

Inventors

• Lee Ernest
• Hartlove Jason

Classifications

• H05B33/14

  characterised by the chemical or physical composition or the arrangement of the electroluminescent material {, or by the simultaneous addition of the electroluminescent material in or onto the light source} · CPC title

• G02F1/133621

  providing coloured light (G02F1/133617, G02F1/133533 take precedence) · CPC title

• G02F1/133615

  Edge-illuminating devices, i.e. illuminating from the side · CPC title

• G02F1/133603

  with LEDs · CPC title

• G02B6/0068

  Arrangements of plural sources, e.g. multi-colour light sources · CPC title