Radiation Absorbing Element for Increasing Color Gamut of Quantum Dot Based Display Devices

• US 20180120492A1
• Filed: 10/19/2017
• Published: 05/03/2018
• Est. Priority Date: 10/31/2016
• Status: Active Grant

• Current Assignee: Shoei Chemical Inc.
• Original Assignee: Nanosys Incorporated (Shoei Electronic Materials, Inc.)
• Inventors: LEE, Ernest, HARTLOVE, Jason
• Granted Patent: US 11,320,577 B2
• Time in Patent Office: Days
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: B82Y 40/00 Manufacture or treatment of nanostructures
• CPC Class Codes: C09K 11/00 Luminescent, e.g. electroluminescent, chemiluminescent materials
• CPC Class Codes: C09K 11/025 non-luminescent particle coatings or suspension media
• CPC Class Codes: C09K 11/703 with zinc or cadmium
• CPC Class Codes: C09K 11/883 with zinc or cadmium
• CPC Class Codes: G02B 6/00 Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
• CPC Class Codes: G02B 6/005 provided by one optical element, or plurality thereof, placed on the light output side of the light guide
• CPC Class Codes: G02B 6/0055 Reflecting element, sheet or layer
• CPC Class Codes: G02B 6/0056 for producing polarisation effects, e.g. by a surface with polarizing properties or by an additional polarizing elements
• CPC Class Codes: G02B 6/0068 Arrangements of plural sources, e.g. multi-colour light sources
• CPC Class Codes: G02B 6/0096 the lights guides being of the hollow type
• CPC Class Codes: G02F 1/1336 Illuminating devices
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133614 using photoluminescence, e.g. phosphors illuminated by UV or blue light
• CPC Class Codes: G02F 1/133615 Edge-illuminating devices, i.e. illuminating from the side
• CPC Class Codes: G02F 1/133621 providing coloured light G02F1/133617, G02F1/133533 take precedence
• CPC Class Codes: G02F 1/133624 characterised by their spectral emissions
• CPC Class Codes: G02F 2001/133614 the light is generated by photoluminescence, e.g. a phosphor is illuminated by UV or blue light
• CPC Class Codes: G02F 2202/36 Micro- or nanomaterials
• CPC Class Codes: H01L 33/50 : Wavelength conversion elements
• CPC Class Codes: H01L 33/502 : Wavelength conversion materials
• CPC Class Codes: H01L 33/507 : the elements being in intimate contact with parts other than the semiconductor body or integrated with parts other than the semiconductor body
• CPC Class Codes: H05B 33/14 : 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

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

Claims

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 process light received from the light source; and

a radiation absorbing element, optically coupled to the quantum dot film, 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.

2. The BLU of claim 1, wherein the standard RGB color space is Rec. 2020 color space.

3. The display device of claim 2, wherein the radiation absorbing element is configured to tune the spectral emission width of the processed light to achieve over 90% color gamut coverage of the Rec. 2020 color space with less than 10% decrease in brightness level of the display device.

4. 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 achieve over 90% color gamut coverage of the Rec. 2020 color space.

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

6. The BLU of claim 1, wherein:

the quantum dot film comprises a matrix; and

the radiation absorbing element is embedded in the matrix.

7. The BLU of claim 1, wherein the radiation absorbing element comprise a dye, ink, paint, or polymeric material.

8. 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.

9. 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.

10. 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.

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

12. 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.

13. The BLU of claim 1, further comprising a reflector;

and

wherein the radiation absorbing element is disposed on a top surface of the reflector.

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

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

16. 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.

17. 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.

18. A display device comprising:

a backlight unit (BLU) comprising;

an optical cavity having a top side, a bottom side, and side walls,

an array of light sources coupled to the optical cavity, and

a quantum dot film, positioned within the optical cavity, configured to process light received from the array of light sources; and

a radiation absorbing element, positioned within the optical cavity, 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 Rec. 2020 color space; and

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

19. The display device of claim 18, wherein:

the quantum dot film comprises a matrix; and

the radiation absorbing element is embedded in the matrix.

20. The display device of claim 18, 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.