Curable Composition for Thin, Angle-Independent Infrared Filters
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Solution Overview
Problem
Existing infrared absorbing filters suffer from noise generation from visible light, high humidity sensitivity, poor angle dependence, and require significant thickness, which affects their performance in recognizing objects using infrared light.
Innovation Solution
A curable composition comprising an infrared absorber and a curable compound, where specific absorbance ratios and wavelength ranges are defined to form a cured film that suppresses visible light noise, enhances humidity resistance, and reduces thickness while maintaining effective infrared transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a multi-layer dielectric film structure is used for infrared absorption, then infrared blocking performance is improved, but visible light transmission is reduced causing noise generation
Solution Approach 1:
The patent applies local quality by using a resin substrate with specific infrared absorption properties combined with a dielectric multi-layer film structure. The resin substrate itself provides selective infrared absorption while maintaining visible light transmission, and the dielectric layers are strategically positioned to enhance infrared blocking only where needed, thereby reducing visible light noise while maintaining infrared performance.
Solution Approach 2:
The patent employs composite materials by combining a resin substrate with specific infrared absorption characteristics and a dielectric multi-layer film. This composite structure leverages the complementary properties of both materials: the resin substrate provides baseline infrared absorption and visible light transmission, while the dielectric layers enhance infrared blocking performance, achieving both goals simultaneously.
2Reliability
If the filter thickness is increased to improve infrared absorption, then blocking performance is enhanced, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent applies parameter changes by optimizing the thickness and refractive index of the dielectric layers in the multi-layer film structure. By carefully selecting and adjusting these parameters, the patent achieves effective infrared blocking with a relatively simple filter structure, avoiding the need for excessive thickness while maintaining performance.
3Reliability
If conventional dielectric films are used, then infrared absorption is achieved, but angle dependence is poor affecting performance at oblique angles
Solution Approach 1:
The patent applies local quality by designing the dielectric multi-layer film with specific local characteristics that provide broadband infrared absorption. The alternating layers of dielectric materials with different refractive indices create local optical properties that maintain effectiveness across various angles of incidence, thereby improving angle independence while preserving infrared absorption capability.
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 results in a cured film that effectively suppresses visible light noise, exhibits excellent humidity resistance, and reduces thickness while maintaining high infrared transmission efficiency and angle independence.
Implementation Method 1
an infrared absorber; and a curable compound, wherein an absorbance X of the infrared absorber at a maximum absorption wavelength in a wavelength range of 400 nm to 1,300 nm and a maximum absorbance Y in a wavelength range of longer than 950 nm and 1,300 nm or shorter satisfy Expression (1)
Implementation Method 2
a curable composition comprising: an infrared absorber; and a curable compound
Data Source
AI summary
A curable composition includes a specific infrared absorber and a curable compound and has specific wavelength characteristics.