Porous Antireflective Coating for Touch Displays
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Solution Overview
Problem
Optical elements, such as touch-screen displays, face issues with antireflective properties and susceptibility to staining and smudging due to oils and dirt, which affect their usability and require expensive coating techniques like vapor deposition.
Innovation Solution
An optical element with an antireflective layer having a refractive index between 1 and 1.41, a pore size of 0 to 300 nm, and a water contact angle of 70° to 120°, formed by applying a silicon-based resin and oxidatively curing it on a substrate, followed by an outermost layer for low friction and easy cleaning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a coating layer is applied to provide antireflective properties, then light transmittance is improved, but manufacturing cost increases due to expensive vapor deposition equipment
Solution Approach 1:
The patent applies a porous silicon-based resin layer with controlled pore sizes (0-300 nm) to achieve antireflective properties. The porous structure reduces light reflection through scattering and interference effects while allowing conventional, cost-effective coating methods to be used instead of expensive vapor deposition equipment
Solution Approach 2:
The patent controls the refractive index of the coating layer by adjusting the pore size and density of the silicon-based resin structure. By varying parameters such as pore size (0-300 nm) and cross-linking density, the refractive index is optimized to minimize reflection across the visible spectrum, achieving antireflective performance without requiring expensive deposition processes
2Ease of operation
If the surface is made smooth for cleaning, then ease of operation is improved, but susceptibility to staining and smudging increases
Solution Approach 1:
The patent creates a hierarchical porous structure on the surface that combines smooth macro-scale properties for easy cleaning with micro-scale pores (0-300 nm) that reduce surface energy. This dual-scale porosity allows the surface to be easily wiped clean while resisting adherence of oils, fingerprints, and other contaminants
Solution Approach 2:
The patent converts the potential harm of surface porosity (which could trap contaminants) into a benefit by controlling pore size and surface chemistry. The optimized porous structure creates low surface energy that causes oils and contaminants to bead up rather than adhere, making the surface easier to clean while maintaining smooth appearance
3Illumination intensity
If the antireflective layer has high light transmittance, then display visibility is improved, but surface friction increases making it more susceptible to smudging
Solution Approach 1:
The patent uses a porous silicon-based resin structure that simultaneously achieves high light transmittance through optimized pore size and distribution, while the porous surface topology reduces friction and smudging by creating a low-adhesion surface that prevents contaminant adherence
Solution Approach 2:
The patent creates a composite structure combining an inorganic silicon-based resin network with organic cross-linking groups. This composite material provides both optical clarity for high transmittance and surface properties that reduce friction and smudging, achieving both optical performance and anti-smudge characteristics in a single integrated layer
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 provides improved anti-glare properties, resistance to smudging, and easy cleaning while maintaining light transmittance, reducing the need for expensive coating methods.
Implementation Method 1
oxidatively curing the silicon-based resin on the substrate to form a first layer
Implementation Method 2
an antireflective layer disposed on and in contact with a substrate and having a refractive index of greater than 1 to less than 1.41
Implementation Method 3
having a pore size ranging from greater than 0 to less than 300 nm
Implementation Method 4
an outermost surface having a water contact angle ranging from greater than or equal to 70 degrees (°) to less than or equal to 120°
Data Source
AI summary
An optical element comprises an antireflective layer that is disposed on and in contact with a substrate. The antireflective layer has a refractive index of greater than 1 to less than 1.41 and has a pore size ranging from greater than 0 to less than 300 nm. The antireflective layer includes an outermost surface having a water contact angle ranging from greater than or equal to 70° to less than or equal to 120° as determined using ASTM 5946-04.