Anti-glare Substrates with Uniform Textured Surface
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Solution Overview
Problem
Existing anti-glare surfaces for consumer electronic devices exhibit sparkle and high pixel power deviation, which worsens with higher definition displays, and current technologies like anti-glare film lamination and sol-gel coating fail to adequately reduce sparkle while maintaining low transmission haze and distortion of image.
Innovation Solution
The development of substrates with a textured surface featuring a plurality of features, where 50% or more of the features have a normalized area between 0.5 and 1.5, and a roughness average (Ra) of 0.15 micrometers or less, achieved through etching with a water-soluble metal ion salt etchant and subsequent acid treatment, resulting in low sparkle, transmission haze, and distortion of image.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If anti-glare surfaces are created through conventional methods (film lamination, sand blasting, sol-gel coating), then specular reflection is reduced, but sparkle and grainy appearance increase significantly
Solution Approach 1:
The patent changes the physical and chemical parameters of the glass surface by controlling the etching process with specific metal ion salts (CuCl2, FeCl3, NiCl2, CoCl2, ZnCl2) at controlled concentrations and temperatures. This produces a textured surface with specific roughness parameters (Ra ≤ 0.15 μm) and feature size distributions that reduce sparkle while maintaining anti-glare properties
Solution Approach 2:
The patent creates localized variations in surface texture by controlling the etching process to produce features with specific size distributions (50-90% of features with normalized area 0.5-1.5). This local control of surface morphology achieves uniform light scattering that minimizes sparkle while maintaining overall anti-glare performance
2Object-affected harmful factors
If surface texture is increased to reduce specular reflection, then anti-glare performance improves, but transmission haze and distortion of image increase
Solution Approach 1:
The patent optimizes the etching parameters including etchant concentration (0.1-10 wt%), temperature (20-80°C), and etching time (1-60 minutes) to create a surface texture with controlled roughness (Ra ≤ 0.15 μm). This controlled parameter change produces sufficient light scattering for anti-glare while limiting image distortion to DOI ≤ 90%
Solution Approach 2:
The patent applies partial etching action by limiting the etching depth and duration to create only the necessary surface texture for anti-glare performance. The etching process is controlled to produce the minimum required roughness (Ra ≤ 0.15 μm) without excessive surface modification that would cause image distortion
3Measurement precision
If display resolution is increased to provide higher definition, then image quality improves, but sparkle becomes more prominent and problematic
Solution Approach 1:
The patent creates a surface with locally controlled feature sizes where 50-90% of features have normalized area 0.5-1.5. This local uniformity in feature size produces consistent light scattering across the display surface, preventing the pixelated sparkle effect that becomes more visible at higher resolutions
Solution Approach 2:
The patent modifies the surface texture parameters through controlled etching to achieve Ra ≤ 0.15 μm and specific feature size distributions. These parameter changes create a surface that scatters light uniformly without creating the fine-grain sparkle pattern that is magnified by high-resolution displays
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 significantly reduces sparkle and distortion of image while maintaining low transmission haze, achieving a pixel power deviation reference (PPDr) of 5% or less, transmission haze of 20% or less, and distortion of image (DOI) of 90% or less, thereby enhancing the visual quality of high-definition displays.
Implementation Method 1
etching with a water-soluble metal ion salt etchant
Implementation Method 2
subsequent acid treatment
Implementation Method 3
The surface texture reduces the reflection light through the random scattering of the reflected light
Data Source
AI summary
Embodiments of an anti-glare article and methods for forming the same are disclosed. In one or more embodiments, the anti-glare article includes a substrate having a surface, and a plurality of features disposed on the surface, wherein about 50% or more of the plurality of features comprise a normalized area in the range from about 0.5 to about 1.5, and the normalized area is defined as the relationship (surface area of a feature/average surface area of all features). In some embodiments, about 90% or more of the features have a surface area of about 100 micrometers or less. The anti-glare article exhibits a PPDr of about 5% or less, a transmission haze of less than about 20% and a DOI of less than about 90%. Methods of forming the substrate are also disclosed and include etching a surface of a substrate with an etchant comprising a water soluble metal ion salt.