Mini LED Backlight Optics for Uniform White Light Distribution

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Solution Overview

Problem

Existing display devices using semiconductor light-emitting elements face issues with non-uniform light distribution, leading to color differences and reduced brightness across viewing angles, which affect the quality of white light synthesis and increase power consumption.

Innovation Solution

A backlight unit design incorporating a base substrate with light emitting diodes, a diffusion layer, and correction lenses, utilizing silicone diffusion agents and anamorphic lenses to enhance light reflection and distribution, ensuring uniform light emission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If semiconductor light-emitting elements are used for display, then device thickness is reduced and various shapes are enabled, but light distribution uniformity deteriorates causing color differences across viewing angles

Engineering Contradiction:

Improvedevice thicknessVSAvoidlight distribution uniformity

Core Design Contradiction:

Volume of moving objectVSStability of the object's composition

Solution Approach 1:

The patent applies local quality by implementing different optical structures at different locations: correction lenses are positioned specifically at corners and edges where light leakage occurs, while the center region uses a different configuration. This localized approach addresses the non-uniform light distribution problem without requiring complete redesign of the entire display structure.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent introduces correction lenses as intermediary optical elements between the semiconductor light-emitting elements and the viewing area. These lenses act as mediators that redirect and uniformize the light distribution, correcting the color differences and viewing angle issues caused by the thin semiconductor LED structure.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Use of energy by stationary object

If mini LEDs are used for backlighting, then power consumption is reduced and contrast ratio is improved, but light extraction efficiency deteriorates due to lateral light emission

Engineering Contradiction:

Improvepower consumptionVSAvoidlight extraction efficiency

Core Design Contradiction:

Use of energy by stationary objectVSLoss of energy

Solution Approach 1:

The patent converts the harmful lateral light emission into a beneficial feature by using correction lenses to redirect the laterally emitted light toward the viewing area. Instead of treating side emission as waste that reduces efficiency, the system captures and utilizes this light, improving overall light extraction efficiency while maintaining the low power consumption advantage of mini LEDs.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent addresses the light extraction problem by operating in another dimension - using optical elements (correction lenses) to control light propagation in three-dimensional space. This allows the system to capture light emitted in multiple directions and redirect it usefully, rather than being constrained to only vertically emitted light.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Ease of manufacture

If conventional LED structure is used, then manufacturing is simpler, but brightness is reduced and power consumption increases due to inefficient light direction

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidbrightness

Core Design Contradiction:

Ease of manufactureVSIllumination intensity

Solution Approach 1:

The patent segments the optical control function by introducing separate correction lens elements at different positions (corners and edges) rather than using a single complex optical structure. This segmentation allows for simpler manufacturing of individual components while achieving the overall goal of improved brightness and light distribution uniformity.

Inventive Principle:

Principle #1Segmentation

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

The solution improves light efficiency, reduces power consumption, and achieves uniform white light emission by minimizing color differences across viewing angles, enhancing the overall brightness and performance of the display device.

Implementation Method 1

a correction lens positioned on each light emitting diode to extract light emitted in a lateral direction from the light emitting diode

Methodology Applied

Scientific EffectLight reflection: Reflection

Implementation Method 2

a diffusion layer positioned around a lateral surface of the light emitting diodes

Methodology Applied

Scientific EffectLight diffusion: Scattering

Data Source

PatentUS20250351651A1Display device using semiconductor light-emitting element

Publication Date: 2025.11.13 LG ELECTRONICS INC

AI summary

The backlight unit according to an embodiment comprises: a base substrate including circuit wiring; a plurality of light-emitting diodes disposed to form an array on the base substrate; a diffusion layer located laterally around the individual light-emitting diodes; and correcting lenses located on top of the respective light-emitting diodes, and can provide uniform white light in all directions through uniform light distribution by reducing color difference for different viewing angles that occurs due to the structure of a semiconductor light-emitting diode.