Quantum Dot Conversion Layers With Low-Refraction Color Filters

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Solution Overview

Problem

Existing display devices face challenges in achieving process economic feasibility while improving display quality, particularly in the manufacturing process and the optimization of light reflectance for enhanced luminance and color sense.

Innovation Solution

The proposed display device incorporates a color filter layer with a low refractive material, such as hollow particles, disposed on a color conversion layer, eliminating the need for a separate low refractive layer. This configuration simplifies the manufacturing process and allows for adjustment of the refractive index and thickness of the color filter layer to optimize reflectance based on the wavelength of light emitted by each pixel.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a separate low refractive layer is added to optimize reflectance, then display quality (luminance and color sense) is improved, but device complexity and manufacturing cost increase

Engineering Contradiction:

ImproveluminanceVSAvoidstructure

Core Design Contradiction:

Illumination intensityVSDevice complexity

Solution Approach 1:

The patent combines the low refractive material function directly into the color filter layer, merging two separate components (color filter and low refractive layer) into a single integrated layer. This eliminates the need for a separate low refractive layer while maintaining the reflectance optimization function, thereby reducing device complexity and manufacturing cost.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The color filter layer is designed to serve multiple functions simultaneously: it provides color filtering and also acts as the low refractive layer for reflectance optimization. By making the color filter layer multi-functional, the patent eliminates the need for additional dedicated low refractive layers, simplifying the overall device structure.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Illumination intensity

If a separate low refractive layer is added to optimize reflectance, then display quality (color sense) is improved, but manufacturing process complexity increases

Engineering Contradiction:

Improvecolor senseVSAvoidmanufacturing process

Core Design Contradiction:

Illumination intensityVSEase of manufacture

Solution Approach 1:

The patent merges the low refractive material function into the color filter layer formation process. By incorporating low refractive particles into the color filter layer material, the patent eliminates the need for separate deposition or application steps for a low refractive layer, thereby simplifying the manufacturing process.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The color filter layer is formulated as a composite material containing low refractive particles (such as hollow silica, hollow acryl, hollow vinyl, or hollow epoxy) dispersed in the color filter matrix. This composite approach allows the color filter layer to provide both color filtering and low refractive index functions through a single material system.

Inventive Principle:

Principle #40Composite materials

3Illumination intensity

If the refractive index and thickness of the color filter layer are adjusted to optimize reflectance, then display quality is improved, but manufacturing precision requirements increase

Engineering Contradiction:

ImprovereflectanceVSAvoidrefractive index control

Core Design Contradiction:

Illumination intensityVSManufacturing precision

Solution Approach 1:

The patent optimizes reflectance by adjusting parameters of the color filter layer, specifically the refractive index (achieved through incorporating low refractive particles) and thickness. By changing these parameters within controlled ranges, the patent achieves optimal reflectance characteristics while maintaining manufacturability.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent applies low refractive material specifically in the color filter layer where it is most needed for reflectance optimization, rather than uniformly across all layers. This localized application of low refractive properties allows for targeted optimization of reflectance at the color filter interface without requiring precision control throughout the entire device structure.

Inventive Principle:

Principle #3Local quality

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

This solution enhances the luminance and color sense of each pixel by optimizing reflectance, while also simplifying the manufacturing process and reducing costs, thereby achieving process economic feasibility.

Implementation Method 1

The color filter layer may include a low refractive material... A refractive index of the color filter layer may be in a range of about 1.2 to about 1.6

Methodology Applied

Scientific EffectRefraction: Refraction

Data Source

PatentUS12336360B2Display devices including conversion layers with quantum dots and low-refraction color filters

Publication Date: 2025.06.17 SAMSUNG DISPLAY CO LTD

AI summary

A display device includes a bank including an opening defining pixels, light emitting elements disposed in the pixels, a color conversion layer disposed on the light emitting elements in the opening, a capping layer overlapping the color conversion layer, and a color filter layer disposed on the capping layer. The color filter layer includes a low refractive material.