Infrared Cut Filter With Copper Phosphonate Layer
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Solution Overview
Problem
Existing infrared cut filters face issues with varying infrared shielding performance due to light incident angle, complexity in production, limited wavelength absorption range, and interaction difficulties between dyes in transparent resins, leading to inconsistent image hue and production challenges.
Innovation Solution
An infrared cut filter comprising an organic dye-containing layer with spectral transmittance decreasing from 70% to 50% over a specific wavelength range and a copper phosphonate-containing layer with fine particles, formed without vacuum deposition or sputtering, to achieve high infrared absorptivity across a broad wavelength range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a reflective cut coating or infrared reflecting film is used to cut off infrared light, then infrared shielding performance is improved, but the shielding performance varies with incident angle causing hue inconsistency and the production process becomes complicated
Solution Approach 1:
The patent replaces the mechanical vacuum deposition or sputtering process with a chemical coating process using a solution containing copper phosphonate and transparent resin. This substitution eliminates the need for complex vacuum equipment and multiple deposition steps, simplifying the production process while maintaining effective infrared cutoff performance.
Solution Approach 2:
The patent uses a composite material system consisting of copper phosphonate particles dispersed in a transparent resin matrix. This composite structure provides both the infrared absorption capability (from copper phosphonate) and the optical transparency in visible range (from the resin), achieving effective infrared shielding without requiring complex reflective multilayer structures.
2Reliability
If multiple dyes are incorporated into a transparent resin to expand infrared absorption range, then infrared absorptivity is improved, but dye interaction makes dispersal difficult
Solution Approach 1:
The patent extracts the infrared absorption function from organic dyes and assigns it to copper phosphonate particles. This separation allows the use of inorganic copper phosphonate which does not suffer from the interaction and dispersal issues that plague mixed organic dye systems, while still achieving broad infrared absorption coverage.
Solution Approach 2:
The patent changes the material parameter from organic dye molecules to inorganic copper phosphonate particles. This parameter change fundamentally alters the interaction behavior, as the particulate inorganic material disperses more uniformly and predictably in the resin matrix compared to multiple organic dye molecules that tend to interact and aggregate.
3Device complexity
If a single infrared absorber material is used, then the structure is simplified, but the infrared absorption wavelength range becomes limited
Solution Approach 1:
The patent applies local quality by using copper phosphonate particles with specific particle size distributions and concentration gradients within the resin matrix. This allows different regions of the coating to contribute to different aspects of infrared absorption, achieving broad spectral coverage while maintaining a relatively simple single-layer structure.
Solution Approach 2:
The patent makes the copper phosphonate-containing coating layer perform multiple functions simultaneously: it provides infrared absorption across a broad wavelength range, maintains visible light transparency, and offers a simple single-step application process. This multi-functionality eliminates the need for multiple specialized layers or materials.
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 filter achieves desired optical properties with high infrared absorptivity and adjustable cut-off wavelength, ensuring consistent image quality without reflective coatings, and simplifies production by avoiding complex deposition processes.
Implementation Method 1
an organic dye-containing layer containing an organic dye so as to have a spectral transmittance that decreases from 70% or more to 50% or less with increasing wavelength
Implementation Method 2
a copper phosphonate-containing layer containing fine particles of copper phosphonate
Data Source
AI summary
The infrared cut filter of the present invention includes an organic dye-containing layer and a copper phosphonate-containing layer containing fine particles of copper phosphonate. The organic dye-containing layer contains an organic dye so as to have a spectral transmittance that decreases from 70% or more to 50% or less with increasing wavelength in a wavelength range between a wavelength 50 nm shorter than a cut-off wavelength of the infrared cut filter and a wavelength 50 nm longer than the cut-off wavelength of the infrared cut filter.