Multi-layer Anti-reflective Layer for Touch Substrates
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Solution Overview
Problem
Conventional touch display panels suffer from high light reflection and color shift due to the high refractive indices of materials like indium tin oxide and silicon oxynitride, leading to low light transmissivity and requiring additional anti-reflective coatings that do not effectively address reflection from the transparent touch electrode layer.
Innovation Solution
A multi-layer anti-reflective structure comprising a first sub-layer, a second sub-layer with a higher refractive index, and a third sub-layer, where the second sub-layer is made of SiOxNy and the first and third sub-layers are made of silicon dioxide or magnesium fluoride, laminated together to reduce light reflection and enhance transmissivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional materials like indium tin oxide and silicon oxynitride are used in touch display panels, then the touch electrode layer can be formed with good electrical conductivity, but high light reflection and color shift occur due to high refractive indices
Solution Approach 1:
The anti-reflective layer is divided into three sub-layers with different refractive indices (first sub-layer: 1.3-1.6, second sub-layer: 1.7-2.0, third sub-layer: 1.3-1.6), creating a gradient structure that progressively reduces reflection from the touch electrode layer by breaking up the abrupt refractive index transition
Solution Approach 2:
The patent uses composite material structure combining different materials (silicon dioxide, silicon oxynitride, magnesium fluoride) with specific refractive indices in a multi-layer configuration, where each layer is selected to optimize the overall anti-reflection performance while maintaining electrical conductivity
2Object-affected harmful factors
If conventional anti-reflective coatings are applied, then light reflection is reduced to some extent, but they do not effectively address reflection from the transparent touch electrode layer and require additional coating steps
Solution Approach 1:
The patent combines the anti-reflection function with the existing touch electrode layer structure by forming the anti-reflective layer directly on the transparent touch electrode layer, merging two functions (touch sensing and anti-reflection) into a single integrated structure rather than adding separate coatings
Solution Approach 2:
The solution moves from conventional single-layer or two-layer anti-reflection coatings to a three-dimensional multi-layer gradient structure, adding depth and complexity in the vertical dimension to achieve superior anti-reflection performance across multiple wavelengths
3Reliability
If high refractive index materials are used to improve electrical conductivity, then touch electrode performance is enhanced, but light transmissivity decreases due to increased reflection
Solution Approach 1:
The patent applies local quality optimization by assigning different refractive indices to different layers based on their specific functions: the first sub-layer (lower refractive index) optimizes for light entry, the second sub-layer (higher refractive index) addresses reflection from the touch electrode, and the third sub-layer (lower refractive index) optimizes for light exit to the display
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 achieves a significant reduction in visible light reflection to less than 1.5% and an increase in transmissivity to over 92%, minimizing color shift and improving light transmission for camera lenses in portable electronic devices.
Implementation Method 1
the anti-reflective layer comprises a first sub-layer on a side of the transparent touch electrode layer distal to the base substrate; a second sub-layer on a side of the first sub-layer distal to the transparent touch electrode layer, and a third sub-layer on a side of the second sub-layer distal to the first sub-layer; wherein the second sub-layer has a refractive index greater than those of the first sub-layer and the third sub-layer
Data Source
AI summary
The present application discloses a touch substrate including a base substrate; a transparent touch electrode layer on the base substrate; and an anti-reflective layer on a side of the transparent touch electrode layer distal to the base substrate. The anti-reflective layer includes a first sub-layer on a side of the transparent touch electrode layer distal to the base substrate; a second sub-layer on a side of the first sub-layer distal to the transparent touch electrode layer; and a third sub-layer on a side of the second sub-layer distal to the first sub-layer. The first sub-layer, the second sub-layer, and the third sub-layer are laminated together. The second sub-layer has a refractive index greater than those of the first sub-layer and the third sub-layer.