Optical Module Wavelength Filtering for Yellow Halo Suppression

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Display devices using Mini LED technology suffer from yellow light diffusion around light spots, leading to non-uniform color distribution and yellow halos, which distort picture details and reduce viewing quality, especially in Local Dimming mode.

Innovation Solution

Incorporation of a wavelength-selective transmission layer that transmits specific colors, such as blue light, while blocking other colors like red and green light, within an optical module to prevent yellow light synthesis and enhance color uniformity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a Mini LED backlight is used to achieve high brightness and high contrast, then display quality is improved, but yellow light diffusion occurs around light spots causing non-uniform color distribution and yellow halos

Engineering Contradiction:

ImprovebrightnessVSAvoidyellow light diffusion

Core Design Contradiction:

Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

A wavelength-selective transmission layer is introduced as an intermediary component between the Mini LED backlight and the display panel. This layer selectively transmits blue light while blocking red and green light, preventing the synthesis of yellow light that causes diffusion and halos. The intermediary layer thus eliminates the harmful effect while preserving the beneficial blue light for excitation of the quantum dot film.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The wavelength-selective transmission layer is applied locally at specific positions where yellow light diffusion occurs, rather than uniformly across the entire display. This targeted approach allows blue light to pass through while blocking red and green light only in regions where yellow halo formation is problematic, thereby maintaining color uniformity without compromising overall display quality.

Inventive Principle:

Principle #3Local quality

2Quantity of substance

If red and green quantum dots are excited by blue light to achieve high color gamut, then color saturation is improved, but yellow light synthesis occurs leading to non-uniform color distribution

Engineering Contradiction:

Improvecolor gamutVSAvoidyellow light synthesis

Core Design Contradiction:

Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

The wavelength-selective transmission layer acts as a mediator that controls which wavelengths reach the quantum dot film. It allows blue light to pass through for exciting the quantum dots (achieving high color gamut) while blocking red and green light before they can combine to form yellow light. This selective transmission prevents yellow light synthesis while maintaining the desired color saturation.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Power

If Local Dimming technology is used to achieve high dynamic contrast, then image quality is improved, but yellow halos appear around light spots reducing viewing quality

Engineering Contradiction:

Improvedynamic contrastVSAvoidyellow halos

Core Design Contradiction:

PowerVSObject-affected harmful factors

Solution Approach 1:

In Local Dimming mode, the wavelength-selective transmission layer prevents yellow light diffusion around dimmed regions by blocking red and green light that would otherwise combine with blue light to create yellow halos. This allows high dynamic contrast to be achieved without the detrimental yellow halo effect, maintaining both contrast performance and color uniformity.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 effectively eliminates yellow halos and ensures uniform color distribution, improving contrast and viewing experience by preventing red and green light from interfering with blue light in the display device.

Implementation Method 1

a wavelength-selective transmission layer stacked between the diffusion plate and the color conversion layer. The wavelength-selective transmission layer is configured to transmit light of a specific color and prevent transmission of light of other colors

Methodology Applied

Scientific EffectWavelength-selective transmission: Filter (optical)

Implementation Method 2

the wavelength-selective transmission layer is a color filter layer and the wavelength-selective transmission layer is configured to transmit light of a specific color and absorb light of other colors

Methodology Applied

Scientific EffectLight absorption: Absorption (EM radiation)

Implementation Method 3

By combining a blue Mini LED with a quantum dot film, red and green quantum dots are excited by blue light, emitting a narrow half-peak wide spectrum

Methodology Applied

Scientific EffectPhotoluminescence: Photoluminescence

Implementation Method 4

a diffusion plate; a color conversion layer stacked on a side of the diffusion plate

Methodology Applied

Scientific EffectLight diffusion: Diffusion

Data Source

PatentUS12560840B2Optical module and tiled display device

Publication Date: 2026.02.24 BEIJING BOE DISPLAY TECH CO LTD

AI summary

An optical module and a tiled display device. The optical module comprises: a diffusion plate (10b); a color conversion layer (20b) provided on one side of the diffusion plate (10b); and a wavelength selective transmission layer (30) provided between the diffusion plate (10b) and the color conversion layer (20b), wherein the wavelength selective transmission layer (30) is configured to transmit light of a specific color and prevent the transmission of light of colors other than the light of the specific color.