Edge-Lit VR-LCD Backlight with Quantum Dot Beam Shaping

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Solution Overview

Problem

Conventional edge-lit BLUs in high-resolution LCD panels suffer from low efficiency and limited color gamut, particularly in near-eye displays, which affect the immersive experience and battery life.

Innovation Solution

Incorporation of a quantum dot film with tailored nanoparticles to convert blue light into red and green light, combined with an optical efficiency enhancement film to modify the angular beam profile, and a hybrid film structure with prisms and micro-structures to improve light collimation and efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If conventional edge-lit BLU is used in high-resolution LCD panels, then device complexity is reduced, but on-axis display efficiency is low and color gamut is limited

Engineering Contradiction:
ImproveBLU structureVSAvoidon-axis display efficiency
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent applies composite materials by integrating a quantum dot film with a hybrid optical film containing prisms and micro-structures. This composite structure combines the wavelength conversion properties of quantum dots with the light scattering and collimation properties of the optical film, achieving both high color gamut and improved on-axis display efficiency without significantly increasing device complexity

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The hybrid optical film incorporates prisms and micro-structures that create local variations in light propagation. These localized optical modifications redirect light at specific angles to enhance on-axis intensity, providing targeted improvement in display efficiency without requiring complete redesign of the entire BLU system

Inventive Principle:
Principle #3Local quality

2Adaptability or versatility

If quantum dot film is added to convert blue light to red and green light, then color gamut is improved, but device complexity and manufacturing difficulty increase

Engineering Contradiction:
Improvecolor gamutVSAvoidmanufacturing process
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent merges the quantum dot film with the optical film into a single hybrid structure. This integration combines multiple functions (wavelength conversion, light scattering, and collimation) into one component, reducing the total number of separate layers and simplifying the manufacturing process while maintaining wide color gamut performance

Inventive Principle:
Principle #5Merging (Combining)

3Productivity

If hybrid film with prisms and micro-structures is used to improve light collimation, then on-axis display efficiency increases, but device complexity increases

Engineering Contradiction:
Improveon-axis display efficiencyVSAvoidoptical film structure
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The hybrid optical film combines prisms and micro-structures in a single integrated layer, creating a composite optical material that performs multiple light manipulation functions simultaneously. This approach achieves improved light collimation and on-axis efficiency without requiring multiple separate optical components, thereby limiting the increase in device complexity

Inventive Principle:
Principle #40Composite materials

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enhances on-axis display efficiency by up to 12% and achieves a large color gamut equivalent to OLED displays, improving the overall performance of LCD panels in near-eye displays.

Implementation Method 1

a quantum dot film including quantum dots dispersed in a polymer matrix

Methodology Applied
Scientific EffectPhotoluminescence: Photoluminescence

Implementation Method 2

a light guide plate configured to receive blue light from the array of blue LEDs, guide the blue light through total internal reflection

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Implementation Method 3

the array of prisms and the array of micro-structures are configured to tune an angular beam profile of light emitted from the hybrid film

Methodology Applied
Scientific EffectRefraction: Refraction

Data Source

PatentEP4432006B1Wide color gamut enabled edge-lit BLU for high PPI VR-LCD display
Publication Date: 2026.02.11 META PLATFORMS TECHNOLOGIES LLC
  • EP4432006B1 patent drawingFigure 1
  • EP4432006B1 patent drawingFigure 2~3
  • EP4432006B1 patent drawingFigure 4

AI summary

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) (1210); a light guide plate (1220) configured to guide the blue light from the array of blue LEDs (1210) through total internal reflection, and couple portions of the blue light guided by the light guide plate (1220) out of the light guide plate (1220); a quantum dot film (1230) including quantum dots configured to absorb blue light and emit red and green light; a brightness enhancement film (1250, 1260) configured to transmit incident light within an angular range and reflect incident light outside of the angular range; and an optical efficiency enhancement film (1240) configured to modify an angular beam profile of light from the quantum dot film (1230) such that the light transmitted by the brightness enhancement film (1260) has a peak intensity in a direction perpendicular to the LC panel.