Infrared Optical Filter Glass Ceramic Composition
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Solution Overview
Problem
Conventional infrared optical filters used in Driver State Monitoring Systems have low infrared light transmittance and visible light blocking efficiency due to the use of colorants and decolorants, which darken the glass and reduce both visible and infrared light transmittance.
Innovation Solution
A glass ceramic layer with increased potassium oxide content, combined with a multilayer oxide thin film and a low reflectivity coating layer, is used to absorb visible and ultraviolet light while maintaining high infrared light transmittance, comprising 60-70% silicon oxide, 0.1-1% aluminum oxide, 10-20% sodium oxide, 10-20% potassium oxide, 0.01-0.1% titanium dioxide, and 0.1-1% selenium, with a multilayer oxide thin film and low reflectivity coating layer to enhance light interference and transmittance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If colorants and decolorants are added to glass ceramic to block visible light, then visible light blocking rate is improved, but infrared light transmittance deteriorates
Solution Approach 1:
The patent changes the chemical composition parameters of the glass ceramic by increasing potassium oxide content to 19-20% (specifically 19.5%) and optimizing other oxides like sodium oxide (10-20%), silicon oxide (60-70%), and aluminum oxide (0.1-1%). This compositional parameter change allows the material to block visible light effectively while maintaining high infrared transmittance without requiring colorants that would degrade infrared performance
Solution Approach 2:
The patent creates a composite glass ceramic material with a specific multi-component oxide system including potassium oxide, sodium oxide, silicon oxide, aluminum oxide, and trace amounts of titanium dioxide and selenium. This composite composition achieves the dual function of visible light absorption and infrared light transmission by combining materials with complementary optical properties, eliminating the need for separate colorant and decolorant additives
2Illumination intensity
If glass ceramic is darkened by additives to block visible light, then visible light transmittance is reduced, but infrared light transmittance also reduces
Solution Approach 1:
The patent optimizes the chemical composition parameters to achieve selective optical absorption. By setting potassium oxide at 19-20% and sodium oxide at 10-20%, the glass ceramic achieves dark coloration for visible light blocking while the specific ratio of these alkali oxides maintains infrared transmission by avoiding the formation of color centers that would absorb infrared wavelengths
Solution Approach 2:
The patent achieves different optical properties in different wavelength ranges within the same material. The glass ceramic composition is designed to have high absorption coefficient for visible light (achieving complete blocking) while maintaining low absorption coefficient for infrared light (achieving 80% or higher transmittance), creating wavelength-selective optical properties without spatial variation
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 complete blocking of visible and ultraviolet light while maintaining high infrared light transmittance of 80% or more, improving the performance of infrared optical filters for applications like Driver State Monitoring Systems.
Implementation Method 1
The glass ceramic layer may include 60 to 70% by weight of silicon oxide (SiO2), 0.1 to 1% by weight of aluminum oxide (Al2O3), 10 to 20% by weight of sodium oxide (Na2O), 10 to 20% by weight of potassium oxide (K2O), 0.01 to 0.1% by weight of titanium dioxide (TiO2), and 0.1 to 1% by weight of selenium (Se)
Implementation Method 2
The multilayer oxide thin film may be formed by alternately stacking a first thin film including silicon (Si) and a second thin film including titanium (Ti)
Data Source
AI summary
An infrared optical filter may include a glass ceramic layer, a multilayer oxide thin film formed on a first surface of the glass ceramic layer, and a low reflectivity coating layer formed on a second surface of the glass ceramic layer.