Infrared Filter Composition with Segmented Absorber Layers
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Solution Overview
Problem
Existing infrared light filters and sensors experience noise issues when used with light sources having wavelengths longer than 1400 nm, as previous films fail to effectively shield visible light while allowing infrared light transmission.
Innovation Solution
A composition comprising a coloring material that transmits infrared light and shields visible light, combined with an infrared absorber that includes compounds with absorption maxima in the 1000-1200 nm range, such as diiminium compounds, squarylium compounds, and rare earth-containing ceramics, to achieve a specific absorbance ratio and spectral characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing infrared light filters are used, then infrared light transmission is achieved, but noise from visible light cannot be minimized
Solution Approach 1:
The filter is divided into multiple functional layers: a first filter layer (700-1300 nm cutoff) and a second filter layer (800-1500 nm cutoff), each targeting specific wavelength ranges. This segmentation allows independent optimization of each layer's spectral characteristics to achieve comprehensive visible light noise reduction while maintaining infrared transmission
Solution Approach 2:
The invention uses composite material structures combining different filter layers with distinct spectral properties. The first filter layer uses materials optimized for 700-1300 nm blocking, while the second layer uses materials optimized for 800-1500 nm blocking, creating a composite structure that achieves superior noise reduction across the visible spectrum while transmitting infrared light
2Object-affected harmful factors
If films are designed to shield visible light, then noise reduction is achieved, but infrared light transmission is compromised
Solution Approach 1:
Each filter layer is designed with localized spectral characteristics: the first layer provides strong attenuation in the 700-1300 nm range while maintaining transmission above 1300 nm, and the second layer provides attenuation in the 800-1500 nm range while transmitting above 1500 nm. This local quality optimization ensures that each layer shields visible light effectively without compromising infrared transmission in its respective transmission window
3Ease of manufacture
If single-layer filters are used, then manufacturing is simple, but spectral characteristics cannot be optimized
Solution Approach 1:
The filter structure is segmented into multiple layers, each with relatively simple individual fabrication processes. The first filter layer can be manufactured independently with standard techniques, and the second filter layer can also be manufactured separately. This segmentation maintains ease of manufacture while enabling complex overall spectral characteristics that would be difficult to achieve in a single layer
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 enables the formation of films and sensors that minimize noise from visible light while allowing high infrared light transmission, specifically achieving low transmittance in the 400-1100 nm range and high transmittance in the 1400-1500 nm range.
Implementation Method 1
a coloring material that allows transmission of infrared light and shields visible light
Implementation Method 2
an infrared absorber that includes compounds with absorption maxima in the 1000-1200 nm range
Data Source
AI summary
Provided is a composition with which a film that allows transmission of infrared light in a state where noise generated from visible light is small can be formed. In addition, provided are a film, a laminate, an infrared transmitting filter, a solid image pickup element, and an infrared sensor. This composition includes: a coloring material that allows transmission of infrared light and shields visible light; an infrared absorber; and a curable compound, in which the infrared absorber includes a material that shields light in a wavelength range of longer than 1000 nm and 1200 nm or shorter. In the composition, a ratio A/B of a minimum value A of an absorbance of the composition in a wavelength range of 400 to 1100 nm to a maximum value B of an absorbance of the composition in a wavelength range of 1400 to 1500 nm is 4.5 or higher.