Composite Reflective Layer for Uniform Mini-LED Low-Gray Emission

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Solution Overview

Problem

Mini-LED display products using active drive mode on glass substrates face issues with uneven lighting and low gray scale performance due to micro-leakage in LED chips, leading to defects in current density and brightness inconsistencies, which are exacerbated by low current levels.

Innovation Solution

A light emitting device with a reflective layer composed of stacked atomic crystal materials, such as aluminum oxide and silicon dioxide, is used to reduce leakage current and improve brightness uniformity, featuring a specific layer structure and deposition processes to minimize defects and enhance optical thickness for improved reflection efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional reflective layer materials are used, then manufacturing is easier, but micro-leakage increases and brightness uniformity deteriorates under low current active drive mode

Engineering Contradiction:

Improvebrightness uniformityVSAvoidmanufacturing complexity

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The reflective layer is constructed as a composite structure with multiple alternating layers of atomic crystal materials (e.g., aluminum oxide, silicon dioxide) and materials with different refractive indices (e.g., titanium dioxide). This composite architecture reduces micro-leakage and improves brightness uniformity under low current active drive mode while maintaining manufacturability through established deposition techniques.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The reflective layer is segmented into multiple thin alternating layers rather than using a single material layer. This segmentation into fine-grained alternating structures of different materials reduces defects and micro-leakage paths, thereby improving reliability and brightness uniformity without significantly complicating the manufacturing process.

Inventive Principle:

Principle #1Segmentation

2Reliability

If atomic crystal material is used in the reflective layer, then micro-leakage is reduced and brightness uniformity is improved, but device complexity increases

Engineering Contradiction:

Improveleakage reductionVSAvoidreflective layer structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The reflective layer employs composite materials comprising alternating layers of atomic crystal materials and materials with different refractive indices. This composite structure reduces micro-leakage and improves brightness uniformity while managing device complexity through systematic material selection and layer design.

Inventive Principle:

Principle #40Composite materials

3Use of energy by moving object

If low current is used in active drive mode, then energy consumption is reduced, but brightness uniformity and chrominance consistency deteriorate due to micro-leakage

Engineering Contradiction:

Improvecurrent consumptionVSAvoidbrightness uniformity

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The composite reflective layer structure compensates for the micro-leakage effects that become prominent at low current levels. By using alternating layers of atomic crystal materials and materials with different refractive indices, the structure maintains brightness uniformity and chrominance consistency even when operating at low current consumption in active drive mode.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The reflective layer design changes the optical and electrical parameters of the device by introducing materials with different refractive indices and atomic crystal structures. This parameter modification reduces micro-leakage and improves brightness uniformity, enabling reliable operation at low current levels in active drive mode.

Inventive Principle:

Principle #35Parameter changes

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 reduces reverse leakage current and enhances brightness uniformity across various gray scales, addressing the issues of uneven lighting and micro-leakage, while maintaining the eye-protective benefits of active drive mode.

Implementation Method 1

a reflective layer which is disposed on the underlay substrate and covers at least part of the light emitting functional layer

Methodology Applied

Scientific EffectLight reflection: Reflection

Data Source

PatentUS20240213422A1Light Emitting Device and Preparation Method Therefor, Light Emitting Substrate and Preparation Method Thereof

Publication Date: 2024.06.27 BOE MLED TECH CO LTD

AI summary

A light emitting device and a preparation method therefor, and a light emitting substrate and a preparation method therefor are provided. The light emitting device includes an underlay substrate, a light emitting functional layer disposed on the underlay substrate, and a reflective layer disposed on the underlay substrate and covering at least part of the light emitting functional layer, the reflective layer includes a first material layer and a second material layer, the first material layer and the second material layer are stacked along a thickness direction of the underlay substrate, the first material layer includes an atomic crystal material, the first material layer is at one side of the second material layer away from the underlay substrate, and a surface of the first material layer away from the second material layer is formed as a surface of the reflective layer away from the underlay substrate.