Transparent Optical Element with Si-Ti-O-N Layer for Automotive Glazing
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Solution Overview
Problem
Existing automotive glazing lighting devices suffer from water absorption issues due to antifog varnish, leading to water sagging and degradation at low temperatures, and non-homogeneous varnish thickness affecting antifog properties.
Innovation Solution
A transparent optical element with a polymer first layer and a second layer comprising silicon, titanium, oxygen, and nitrogen, exhibiting optimized photocatalytic activity to prevent water dripping and ensure consistent antifog properties, fabricated using methods like atmospheric plasma deposition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If antifog varnish is applied to the internal face of the transparent closure outer lens, then antifog properties are improved, but water absorption increases causing water sagging and micro cracks at low temperatures
Solution Approach 1:
The patent applies a composite coating structure consisting of a first transparent polymer layer and a second transparent layer containing silicon, titanium, oxygen and nitrogen. This composite structure combines the antifog properties of the polymer layer with the photocatalytic and water-repelling properties of the inorganic-containing second layer, thereby maintaining antifog performance while preventing water sagging and micro crack formation.
Solution Approach 2:
The patent modifies the chemical composition parameters of the coating by incorporating specific elements (silicon, titanium, oxygen, nitrogen) in controlled proportions. The second layer contains 30-90% silicon, 1-70% titanium, 40-60% oxygen, and 0.0001-5% nitrogen by weight, creating a material with optimized photocatalytic activity and water resistance properties that prevent water absorption while maintaining antifog functionality.
2Reliability
If varnish is applied to the interior surface, then antifog properties are achieved, but thickness non-homogeneity affects antifog performance consistency
Solution Approach 1:
The patent replaces the mechanical application method (brush or spray coating of varnish) with a chemical vapor deposition process. This substitution allows for atomic-level control of layer thickness and composition, ensuring homogeneous coverage across the entire lens surface without the thickness variations inherent in manual or spray application methods.
Solution Approach 2:
The deposition process parameters (temperature, pressure, gas flow rates, deposition time) are precisely controlled to achieve uniform thickness of the second layer. The process parameters are optimized to ensure consistent layer formation, with the second layer thickness controlled to be between 1-100 nm, providing homogeneous photocatalytic and water-resistant properties across the entire surface.
3Reliability
If a second layer with silicon, titanium, oxygen and nitrogen is deposited, then photocatalytic activity and water dripping prevention are improved, but device complexity increases
Solution Approach 1:
The patent merges multiple functions into a single integrated coating system. The first transparent polymer layer provides the base antifog properties, while the second layer containing silicon, titanium, oxygen and nitrogen simultaneously provides photocatalytic activity for self-cleaning, water repelling properties to prevent water sagging, and enhanced durability. This merging of multiple protective functions into one coating structure avoids the need for separate layers for each function, thereby limiting overall device complexity.
Solution Approach 2:
The second layer serves multiple functions simultaneously: it provides photocatalytic activity for organic contaminant degradation, creates hydrophilic surfaces to prevent water droplet formation, and enhances the overall durability and resistance of the coating system. This multi-functionality in a single layer reduces the number of separate components needed, thereby limiting device complexity while maximizing protective performance.
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 limits water dripping, maintains effective antifog properties over time, and ensures homogeneous coverage, with the photocatalytic activity enhancing chemical reactions under visible light, maintaining image quality and luminous transmission.
Implementation Method 1
the photocatalytic activity allows chemical reactions to occur in the presence of light. Its principle is based on the generating of electron-hole pairs in a semiconductor material by absorption of photons whose energy is at least equal to the width of the forbidden band of the material
Implementation Method 2
fabricated using methods like atmospheric plasma deposition
Data Source
AI summary
A transparent optical element for a motor vehicle includes at least one first transparent layer of a polymer material. The optical element further has at least one second transparent layer including at least silicon, titanium, oxygen and nitrogen.