Multilayer Antireflection Coating for Display Modules
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Solution Overview
Problem
Existing display devices face challenges in achieving high surface hardness and antireflection properties, which are essential for durability and visibility, especially when exposed to external light and repeated use.
Innovation Solution
A display module is designed with a structure that includes a display panel, an optical layer, and an antireflection layer. The antireflection layer is composed of multiple layers: a first layer of silicon oxynitride, a second layer of silicon nitride, and a third layer of polysilazane, which are deposited in succession to achieve the desired refractive indices and thicknesses, resulting in low reflectance and high surface hardness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a single-layer antireflection coating is applied to the display panel, then the manufacturing process is simple, but the surface hardness and impact resistance are insufficient
Solution Approach 1:
The patent divides the antireflection coating into multiple layers (typically three layers with different refractive indices) instead of using a single-layer coating. Each layer has specific thickness and material composition optimized for different functions: the first layer provides antireflection, the second layer enhances surface hardness, and the third layer provides impact resistance. This segmentation allows each layer to specialize in specific properties rather than trying to achieve all properties in one layer.
Solution Approach 2:
The patent uses composite material structures where each layer is made of different materials with specific properties. The antireflection layer uses low refractive index materials, the hardness enhancement layer uses high refractive index materials like silicon nitride or silicon oxynitride, and the impact resistance layer uses materials with high mechanical strength. This composite structure combines the benefits of different materials to achieve multiple properties simultaneously.
2Illumination intensity
If the display panel is exposed to external light, then the display can be viewed in ambient conditions, but reflected light creates images that reduce visibility and cause eye fatigue
Solution Approach 1:
The patent changes the optical parameters of the surface coating by creating a gradient refractive index structure through multiple layers. Each layer has a different refractive index, creating a gradual transition from the air interface to the display panel substrate. This parameter change optimizes light transmission while minimizing reflection across different wavelengths and angles of incidence, reducing reflected light without blocking ambient light transmission.
Solution Approach 2:
The patent addresses the reflection problem by adding a dimensional aspect - creating a multi-layered structure with varying thicknesses and refractive indices at different depths from the surface. Instead of treating the surface as a single plane, the solution extends into the vertical dimension with multiple interfaces, each designed to control light behavior differently, thereby reducing overall reflection while maintaining transmission.
3Duration of action of moving object
If repeated use and exposure to external environment occur, then the display device is used continuously, but durability and reliability deteriorate
Solution Approach 1:
The patent applies protective layers beforehand to cushion the display panel against future damage. The multi-layer antireflection coating is designed with the outer layers having high surface hardness and impact resistance properties, serving as a protective barrier that absorbs and distributes mechanical stress from external impacts, scratches, and environmental exposure before they reach the underlying display panel, thereby extending durability.
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 proposed solution effectively enhances the durability and visibility of the display module by achieving low reflectance and high surface hardness, making it suitable for use in tiling display devices where multiple modules are combined.
Implementation Method 1
an antireflection layer disposed on the optical layer, where the antireflection layer includes a first layer including silicon oxynitride, a second layer disposed on the first layer and including silicon nitride, and a third layer disposed on the second layer and including polysilazane. In an embodiment, a refractive index of the first layer may be about 1.60 or greater and about 1.69 or less, a refractive index of the second layer may be about 1.70 or greater and about 1.90 or less, and a refractive index of the third layer may be about 1.35 or greater and about 1.45 or less.
Data Source
Figure 1A
Figure 1B
Figure 2A~2B
AI summary
A display module includes a display panel, an optical layer disposed on the display panel, an antireflection layer disposed on the optical layer, and the antireflection layer includes a first layer including silicon oxynitride, a second layer disposed on the first layer and including silicon nitride, and a third layer disposed on the second layer and including polysilazane.