White point uniformity in display devices

Patent metadata

Field	Value
Publication number	US-10984735-B2
Application number	US-201615098608-A
Country	US
Kind code	B2
Filing date	Apr 14, 2016
Priority date	Apr 17, 2015
Publication date	Apr 20, 2021
Grant date	Apr 20, 2021

Abstract

Embodiments of a device and a method of tuning white point values of light distributed by a backlight unit of a display device are described. The device includes a backlight unit, an image generating unit, and a patterned layer. The backlight unit includes a light source unit and an optical processing unit having a quantum dot film coupled to the light source unit. The image generating unit includes a display screen. The backlight unit is configured to distribute light to the display screen and the patterned layer is configured to tune white point values of the distributed light to a desired white point value in order to achieve substantially uniform white point values across the display screen.

First claim

What is claimed is:

1. A device comprising:
a backlight unit comprising:
a light source unit having a light guide plate; and
an optical processing unit comprising a quantum dot film coupled to the light source unit;

an image generating unit comprising a display screen coupled to the backlight unit,
wherein the backlight unit is configured to distribute light emitted by the quantum dot film across the display screen; and
a color correction film comprising a patterned layer, wherein the color correction film is disposed between the quantum dot film and the light guide plate,
wherein the patterned layer is configured to receive the light emitted by the quantum dot film and to tune white point values of the light emitted by the quantum dot film at different locations on the display screen to a desired white point value in order to achieve more uniform white point values across the display screen, and
wherein the patterned layer comprises:
a first pattern of a transparent polymeric material having a first color that is different from one or more colors of the light emitted by the quantum dot film, and
a second pattern of another transparent polymeric material having a second color that is different from the first color and the one or more colors of the light emitted by the quantum dot film.

2. The device of claim 1 , wherein the patterned layer is disposed on the quantum dot film.

3. The device of claim 1 , wherein the patterned layer is disposed on a substrate that is disposed on the quantum dot film.

4. The device of claim 1 , wherein the image generating unit further comprises a liquid crystal display module coupled to the display screen, wherein the patterned layer is disposed on the liquid crystal display module.

5. The device of claim 1 ,
wherein the first and second patterns are configured to receive the light emitted by the quantum dot film and to tune white point values of the light emitted by the quantum dot film at first and second locations, respectively, on the display screen, the first and second locations being different from each other.

6. The device of claim 1 , wherein:
the first pattern of the transparent polymeric material has a first density; and
the second pattern of the transparent polymeric material has a second density, the first and second densities being different from each other,
wherein the first and second patterns are configured to receive the light emitted by the quantum dot film and to tune white point values of the light emitted by the quantum dot film at first and second locations, respectively, on the display screen, the first and second locations being different from each other.

7. The device of claim 1 , wherein:
the first pattern of the transparent polymeric material comprises a yellow color film; and
the second pattern of the transparent polymeric material comprises a cyan color film.

8. The device of claim 1 , wherein the light source unit comprises a light emitting diode.

9. The device of claim 1 , wherein the light source unit comprises an array of light emitting diodes facing a bottom surface of the quantum dot film.

10. The device of claim 1 , wherein the optical processing unit further comprises:
a brightness enhancing film coupled to the quantum dot film; and a polarizing film coupled to the brightness enhancing film.

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

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

13. The device 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.

14. The device of claim 1 , wherein the device comprises at least one of a display device, a liquid crystal display device, a computer, a tablet, a hand-held device, a phone, a wearable device, and a TV.

15. A method of obtaining uniform white point values of light distributed by a backlight unit of a display device, the method comprising:
providing a light source unit;
providing an optical processing unit comprising a quantum dot film;
providing an image generating unit; and
providing a color correction film comprising a layer of patterned material to tune white point values of the distributed light to a desired white point value in order to achieve more uniform white point values across the display screen;
wherein the providing the color correction film comprising the layer of patterned material comprises:
determining the white point values of the distributed light at different locations on the display screen without the layer of patterned material;
comparing each of the determined white point values with the desired white point value;
determining a pattern to correct one or more white point values of the determined white point values in response to the one or more white point values being larger or smaller than the desired white point value by a predetermined value;
determining a first color for a first sub-pattern of the pattern, wherein the first color is different from one or more colors of light emitted by the quantum dot film; and
determining a second color for a second sub-pattern of the pattern, wherein the second color is different from the first color and the one or more colors of light emitted by the quantum dot film.

16. The method of claim 15 , further comprising
determining density for material of each sub-pattern of the pattern.

17. The method of claim 15 , wherein the providing of the layer of patterned material comprises disposing the layer of patterned material on a light guide plate of the light source unit.

18. The method of claim 15 , wherein the providing of the layer of patterned material comprises disposing the layer of patterned material on the quantum dot film of the optical processing unit.

19. The method of claim 15 , wherein the providing of the layer of patterned material comprises disposing the layer of patterned material on a liquid crystal display module of the image generating unit.

20. The method of claim 15 , wherein the providing of the layer of patterned material comprises:
disposing the layer of patterned material on a substrate; and
disposing the substrate on a quantum dot film of the optical processing unit.

Assignees

• Nanosys Inc

Inventors

• Chen Jian
• Lee Ernest
• Wilson Robert E
• Gensler Steven

Classifications

• G02F2202/36

  Micro- or nanomaterials · CPC title

• G09G3/342 Primary

  using several illumination sources separately controlled corresponding to different display panel areas, e.g. along one dimension such as lines · CPC title

• G02B6/0073

  Light emitting diode [LED] · CPC title

• G02F1/133609 Primary

  including means for improving the color mixing, e.g. white · CPC title

• G02B6/005

  provided by one optical element, or plurality thereof, placed on the light output side of the light guide · CPC title