Black Matrix Light Reflection Layer for Flat Panel Displays

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Solution Overview

Problem

Conventional black matrices in flat panel displays suffer from energy loss due to absorption of light emitted from the display, leading to reduced contrast and image quality under external illumination, as they absorb environmental light to improve contrast.

Innovation Solution

A black matrix structure comprising a microstructure layer, a light absorption layer, and a light reflection layer is arranged on a substrate, with the light reflection layer positioned obliquely to redirect incident light away from the display, reducing reflection and enhancing luminous exitance by allowing light to pass through opening areas, thereby minimizing energy loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a conventional black matrix structure with chromic oxide, chromic nitride and chrome layers is used to absorb environmental light, then contrast is improved, but energy is lost due to absorption of light emitted from the display

Engineering Contradiction:

Improveenvironmental light interferenceVSAvoiddisplay light energy

Core Design Contradiction:

Object-affected harmful factorsVSLoss of energy

Solution Approach 1:

The black matrix is divided into multiple functional layers: a light absorption layer (chromic oxide and chromic nitride) for absorbing environmental light, and a light reflection layer (chrome) for reflecting display light. This segmentation allows each layer to perform its specific function independently, enabling the system to absorb harmful environmental light while preserving useful display light energy.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different layers of the black matrix are assigned different optical properties: the chromic oxide and chromic nitride layers have light-absorbing properties to handle environmental light, while the chrome layer has light-reflecting properties to preserve display light. This local differentiation of material properties enables simultaneous contrast improvement and energy conservation.

Inventive Principle:

Principle #3Local quality

2Object-affected harmful factors

If a polarizer is attached to the outer surface of the OLED display to improve contrast, then display quality is improved, but energy loss occurs due to absorption by the polarizer

Engineering Contradiction:

Improveenvironmental light disturbanceVSAvoidlight energy

Core Design Contradiction:

Object-affected harmful factorsVSLoss of energy

Solution Approach 1:

Instead of using a polarizer that absorbs both environmental and display light, the invention uses a reflective black matrix structure where the chrome layer reflects display light back through the organic electroluminescent device. This inverted approach converts the traditional absorption mechanism into a reflection-based mechanism, thereby reducing energy loss while maintaining contrast improvement.

Inventive Principle:

Principle #13The other way round (Inversion)

3Object-affected harmful factors

If the black matrix absorbs environmental light to improve contrast, then contrast ratio is enhanced, but luminous exitance is reduced due to energy loss

Engineering Contradiction:

Improvereflection light from environmental lightVSAvoidluminous exitance

Core Design Contradiction:

Object-affected harmful factorsVSIllumination intensity

Solution Approach 1:

The chrome reflection layer recovers display light that would otherwise be absorbed by the black matrix or lost. By reflecting this light back through the organic electroluminescent device, the system recovers luminous energy, thereby maintaining high luminous exitance while the light absorption layer simultaneously discards harmful environmental light to preserve contrast.

Inventive Principle:

Principle #34Discarding and recovering

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 configuration improves contrast and luminous exitance by redirecting incident light, reducing image blur and enhancing optical coupling efficiency, while maintaining high contrast and brightness in flat panel displays.

Implementation Method 1

the black matrix structure 10 may absorb part of the environmental light and thus reduce the reflection light caused by the environmental light

Methodology Applied

Scientific EffectLight absorption: Absorption (EM radiation)

Implementation Method 2

a light reflection layer, and a microstructure layer, with the light reflection layer arranged obliquely on the microstructure layer

Methodology Applied

Scientific EffectLight reflection: Reflection

Data Source

PatentEP3109902B1Black matrix, flat screen display and manufacturing method thereof

Publication Date: 2023.04.05 BOE TECHNOLOGY GROUP CO LTD

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AI summary

The present disclosure provides a black matrix, a flat panel display device including the black matrix and a method for producing the same. The black matrix is arranged on a surface of a substrate located in a first plane, the black matrix including: a light absorption layer, a microstructure layer and a light reflection layer, the absorption layer being formed between the microstructure layer and the surface of the substrate, and the light reflection layer being arranged on a face of the microstructure layer facing away from the absorption layer. The microstructure layer is configured such that a light incident on the light reflection layer in a direction perpendicular to the first plane is emitted out obliquely with respect to the first plane after the light is reflected by the light reflection layer. The absorption layer may be formed at a side of the microstructure layer, or on the substrate.