White Point Uniformity in Display Devices

• US 20160307519A1
• Filed: 04/14/2016
• Published: 10/20/2016
• Est. Priority Date: 04/17/2015
• Status: Active Grant

• Current Assignee: Shoei Chemical Inc.
• Original Assignee: Nanosys Incorporated (Shoei Electronic Materials, Inc.)
• Inventors: WILSON, Robert E., GENSLER, Steven, CHEN, Jian, LEE, Ernest
• Granted Patent: US 10,984,735 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• 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 6/0073 Light emitting diode [LED]
• CPC Class Codes: G02F 1/133514 Colour filters
• CPC Class Codes: G02F 1/133606 including a specially adapted diffusing, scattering or light controlling members
• CPC Class Codes: G02F 1/133609 including means for improving the color mixing, e.g. white
• CPC Class Codes: G02F 1/133614 using photoluminescence, e.g. phosphors illuminated by UV or blue light
• CPC Class Codes: G02F 2202/36 Micro- or nanomaterials
• CPC Class Codes: G09G 2320/0233 Improving the luminance or brightness uniformity across the screen
• CPC Class Codes: G09G 2320/0242 Compensation of deficiencies in the appearance of colours
• CPC Class Codes: G09G 3/32 semiconductive, e.g. using light-emitting diodes [LED]
• CPC Class Codes: G09G 3/342 using several illumination sources separately controlled corresponding to different display panel areas, e.g. along one dimension such as lines

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.

Claims

1. A device comprising:

a backlight unit comprising;

a light source unit; 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 across the display screen; and

a patterned layer configured to tune white point values of the distributed light at different locations on the display screen to a desired white point value in order to achieve substantially more uniform white point values across the display screen.

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 module.

5. The device of claim 1, wherein the light source unit comprises a light guide plate, wherein the patterned layer is interposed between the quantum dot film and the light guide plate.

6. The device of claim 1, wherein the patterned layer comprises:

a first pattern of a material having a first color; and

a second pattern of the material having a second color, the first and second colors being different from each other.

7. The device of claim 1, wherein the patterned layer comprises:

a first pattern of a material having a first density; and

a second pattern of the material having a second density, the first and second densities being different from each other.

8. The device of claim 1, wherein the patterned layer comprises:

a first film of a material having a first color; and

a second film of the material having a second color, the first and second colors being different from each other.

9. The device of claim 6, wherein the material is a paint, dye, ink, or polymeric material.

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

11. 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.

12. 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.

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

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

15. 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.

16. 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.

17. 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;

providing an image generating unit; and

providing a layer of patterned material to tune white point values of the distributed light to a desired white point value in order to achieve substantially more uniform white point values across the display screen.

18. The method of claim 17, wherein the providing of the layer of patterned material comprises:

determining the white point values of the distributed light at different locations on the display screen;

comparing each of the determined white point values with the desired white point value; and

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.

19. The method of claim 18, wherein the determining of the pattern comprises;

determining color of the material for each sub-pattern of the pattern, wherein each sub-pattern corresponds to each of the one or more white point values; and

determining density of the material for each sub-pattern of the pattern.

20. The method of claim 17, 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.

21. The method of claim 17, wherein the providing of the layer of patterned material comprises disposing the layer of patterned material on a quantum dot film of the optical processing unit.

22. The method of claim 17, 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.

23. The method of claim 17, 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.