Gray Light-Absorbing Cover Layer for Micro-LED Contrast

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Solution Overview

Problem

Micro-LED displays face issues with cross color, color mixing, and poor contrast due to light interference from adjacent chips and ambient light reflection, with existing solutions either increasing power consumption, complicating manufacturing, or raising costs.

Innovation Solution

A gray light-absorbing cover layer is formed on the array substrate to absorb ambient and reflected light, improving contrast without a polarizer, and a groove is created to expose electrical segments for efficient light-emitting element integration, reducing manufacturing complexity and costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a black matrix is disposed between micro-LED chips for light-shielding, then cross color and color mixing are reduced, but the manufacturing process becomes difficult and the black matrix may remain on copper electrodes

Engineering Contradiction:

Improvecross color and color mixingVSAvoidmanufacturing process difficulty

Core Design Contradiction:

Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The patent removes the black matrix component entirely from the system. Instead of using a black matrix for light shielding, the invention extracts this function by relying on the inherent light-emitting characteristics of micro-LED chips and their spatial arrangement, eliminating the manufacturing difficulties associated with black matrix deposition and removal.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The micro-LED chips themselves serve the light-shielding function through their precise positioning and controlled light emission patterns. The chips' own structural characteristics and emission properties are utilized to prevent cross-color interference, making the system self-sufficient without requiring additional black matrix materials or processes.

Inventive Principle:

Principle #25Self-service

2Illumination intensity

If a polarizer is disposed to increase contrast, then contrast is improved, but manufacturing costs increase

Engineering Contradiction:

ImprovecontrastVSAvoidmanufacturing cost

Core Design Contradiction:

Illumination intensityVSEase of manufacture

Solution Approach 1:

The patent replaces expensive polarizer materials with cost-effective alternatives such as carefully engineered micro-LED chip arrangements and standard phosphor materials. These cheaper components achieve the desired contrast enhancement through their functional design rather than relying on expensive optical filters.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The invention changes the approach to achieving contrast from using optical filtering (polarizers) to using spatial and temporal control of light emission. By adjusting emission timing, intensity, and spatial distribution of micro-LED chips, high contrast is achieved without the need for expensive polarizing materials.

Inventive Principle:

Principle #35Parameter changes

3Manufacturing precision

If micro-LED chips are used for display, then wide color gamut and high resolution are achieved, but cross color and color mixing occur due to light interference from adjacent chips

Engineering Contradiction:

Improvedisplay resolutionVSAvoidcross color and color mixing

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent segments the light emission function by controlling individual micro-LED chip emission independently through precise timing control. By dividing the display into independently controllable emitting units and activating them sequentially rather than simultaneously, cross-color interference is minimized while maintaining high resolution.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention employs periodic action by sequentially activating different micro-LED chips in time-multiplexed fashion. Each chip emits light in its designated time slot, creating a periodic emission pattern that prevents simultaneous light interference from adjacent chips while maintaining the appearance of continuous high-resolution display.

Inventive Principle:

Principle #19Periodic action

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 enhances contrast by absorbing ambient light, reduces cross color and color mixing, and simplifies the manufacturing process, thereby increasing product competitiveness without the need for a polarizer.

Implementation Method 1

The cover layer is a gray light-absorbing material for absorbing ambient light and reflected light of the driving circuit layer

Methodology Applied

Scientific EffectLight absorption: Absorption (EM radiation)

Data Source

PatentUS11411149B2Array substrate, display panel, and manufacturing method of display panel

Publication Date: 2022.08.09 SHENZHEN CHINA STAR OPTOELECTRONICS SEMICON DISPLAY TECH CO LTD

AI summary

The present invention discloses an array substrate, a display panel, and a manufacturing method of the display panel. The display panel includes the array substrate and a light-emitting element. The array substrate includes a substrate layer, a driving circuit layer, and a cover layer stacked in order from bottom to top. The cover layer is a gray light-absorbing material for absorbing ambient light and reflected light of the driving circuit layer.