Wide color gamut enabled edge-lit BLU for high PPI VR-LCD display

Patent metadata

Field	Value
Publication number	US-12523907-B2
Application number	US-202418590840-A
Country	US
Kind code	B2
Filing date	Feb 28, 2024
Priority date	Mar 13, 2023
Publication date	Jan 13, 2026
Grant date	Jan 13, 2026

Abstract

A liquid crystal display panel for near-eye display comprises a liquid crystal (LC) panel and a backlight unit (BLU). The BLU includes an array of blue light-emitting diodes (LEDs); a light guide plate configured to guide the blue light from the array of blue LEDs through total internal reflection, and couple portions of the blue light guided by the light guide plate out of the light guide plate; a quantum dot film including quantum dots configured to absorb blue light and emit red and green light; a brightness enhancement film configured to transmit incident light within an angular range and reflect incident light outside of the angular range; and an optical efficiency enhancement film configured to modify an angular beam profile of light from the quantum dot film such that the light transmitted by the brightness enhancement film has a peak intensity in a direction perpendicular to the LC panel.

First claim

What is claimed is:

1 . A liquid crystal display (LCD) panel comprising:
a liquid crystal (LC) panel; and a backlight unit comprising:
an array of blue light-emitting diodes (LEDs);
a light guide plate configured to receive blue light from the array of blue LEDs, guide the blue light through total internal reflection, and couple portions of the blue light guided by the light guide plate out of the light guide plate;
a quantum dot film including quantum dots configured to absorb blue light and emit red and green light, wherein the quantum dot film comprises micro-structures configured to diffuse light on opposing sides of the quantum dot film;
a brightness enhancement film configured to transmit incident light within an angular range and reflect incident light outside of the angular range, the brightness enhancement film including:
a first brightness enhancement film oriented generally perpendicular to a second brightness enhancement film, and
the first brightness enhancement film is positioned on the second brightness enhancement film such that a surface of the first brightness enhancement film is in direct contact with an additional surface of the second brightness enhancement film; and

an optical efficiency enhancement film between the quantum dot film and the brightness enhancement film, the optical efficiency enhancement film configured to modify an angular beam profile of light from the quantum dot film such that: a peak intensity of light emitted from the optical efficiency enhancement film is in a direction with at least one of an azimuthal angle greater than 0° or a polar angle greater than 0°, and the light transmitted by the brightness enhancement film has a peak intensity in a direction perpendicular to the LC panel.

2 . The LCD panel of claim 1 , wherein the optical efficiency enhancement film includes prisms, pyramids, negative pyramids, truncated pyramids, hemi-spheres, waffle, or a combination thereof.

3 . The LCD panel of claim 1 , wherein the optical efficiency enhancement film includes prisms on one side and pyramids on an opposing side.

4 . The LCD panel of claim 1 , wherein the quantum dot film includes:
a first barrier layer; a second barrier layer; and a quantum dot matrix material layer between the first barrier layer and the second barrier layer, the quantum dot matrix material layer including the quantum dots dispersed in a polymer matrix, wherein the micro-structures comprise prisms on the first barrier layer and at least one of pyramids, negative pyramids, truncated pyramids, hemi-spheres, a waffle, or a combination thereof on the second barrier layer.

5 . The LCD panel of claim 1 , wherein the quantum dots include:
nanoparticles of a first size and configured to absorb blue light and emit red light; and nanoparticles of a second size and configured to absorb blue light and emit green light.

6 . The LCD panel of claim 1 , wherein the micro-structures configured to diffuse light comprise particulates formed on the opposing sides of the quantum dot film.

7 . The LCD panel of claim 1 , wherein:
the backlight unit further comprises a reflector film; the light guide plate is between the reflector film and the quantum dot film; and the reflector film is configured to reflect incident light towards the light guide plate and the quantum dot film.

8 . The LCD panel of claim 1 , wherein the backlight unit further comprises a reflective polarizer between the LC panel and the brightness enhancement film, the reflective polarizer configured to transmit light of a first polarization state and reflect light of a second polarization state that is orthogonal to the first polarization state.

9 . The LCD panel of claim 8 , wherein the reflective polarizer is coupled to the LC panel.

10 . The LCD panel of claim 1 , wherein the array of blue LEDs is at an edge of the light guide plate.

11 . The LCD panel of claim 1 , wherein:
a thickness of the quantum dot film is less than 60 μm; and a thickness of the optical efficiency enhancement film is less than 100 μm.

12 . A liquid crystal display (LCD) panel comprising:
a liquid crystal (LC) panel; and a backlight unit comprising:
an array of blue light-emitting diodes (LEDs);
a light guide plate configured to receive blue light from the array of blue LEDs, guide the blue light through total internal reflection, and couple portions of the blue light guided by the light guide plate out of the light guide plate;
a brightness enhancement film configured to transmit incident light within an angular range and reflect incident light outside of the angular range, the brightness enhancement film including:
a first brightness enhancement film oriented generally perpendicular to a second brightness enhancement film, and
the first brightness enhancement film is positioned on the second brightness enhancement film such that a surface of the first brightness enhancement film is in direct contact with an additional surface of the second brightness enhancement film; and

a hybrid film between the light guide plate and the brightness enhancement film, the hybrid film including:
a quantum dot film including quantum dots dispersed in a polymer matrix;
a first coating layer between the quantum dot film and the light guide plate and including an array of prisms; and
a second coating layer between the quantum dot film and the brightness enhancement film and including micro-structures configured to diffuse light,
wherein the first coating layer and the second coating layer are configured to tune an angular beam profile of light emitted from the hybrid film such that: a peak intensity of the light emitted from the hybrid film is in a direction with at least one of an azimuthal angle greater than 0° or a polar angle greater than 0°, and the light transmitted by the brightness enhancement film has a peak intensity in a direction perpendicular to the LC panel.

13 . The LCD panel of claim 12 , wherein the micro-structures include pyramids, negative pyramids, truncated pyramids, hemi-spheres, a waffle, or a combination thereof.

14 . The LCD panel of claim 12 , wherein the quantum dots include:
nanoparticles of a first size and configured to absorb blue light and emit red light; and nanoparticles of a second size and configured to absorb blue light and emit green light.

15 . The LCD panel of claim 12 , wherein:
the backlight unit further comprises a reflector film; the light guide plate is between the reflector film and the quantum dot film; and the reflector film is configured to reflect incident light towards the light guide plate and the hybrid film.

16 . The LCD panel of claim 12 , wherein the backlight unit further comprises a reflective polarizer between the LC panel and the brightness enhancement film, the reflective polarizer configured to transmit light of a first polarization state and reflect light of a second polarization state that is orthogonal to the first polarization state.

17 . The LCD panel of claim 12 , wherein a thickness of the hybrid film is less than 100 μm.

18 . The LCD panel of claim 12 , wherein the LC panel is characterized by a resolution greater than 600 pixels per inch.

Assignees

• Meta Platforms Tech Llc

Inventors

• Ye Shenglin
• Zhu Xinyu
• Kitsomboonloha Rungrot
• Kim Cheonhong
• Hallstein Sascha
• Han Wook Jin
• Ma Ruiqing
• Li Xiangtong
• Wang Yu-Jen

Classifications

• G02F1/133615

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

• G02F1/133621

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

• G02F1/133528

  Polarisers · CPC title

• G02B6/0053

  Prismatic sheet or layer; Brightness enhancement element, sheet or layer · CPC title

• G02B5/045

  Prism arrays · CPC title