Near Infrared Cut Filter Using Curable Lake Dye Composition
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Solution Overview
Problem
Conventional near infrared cut materials for solid state imaging devices lack sufficient heat resistance and light fastness, and are unable to effectively distinguish between the visible and near infrared regions, making them unsuitable for practical use as a substitute for seal glass.
Innovation Solution
A curable composition comprising a lake dye with maximum absorption in the 700 nm to 1100 nm wavelength range, combined with a thermo-setting or photo-setting compound, which forms a filter that is both heat-resistant and light-fast, using specific dye structures such as cyanine, oxonol, squarylium, and croconium dyes in an aggregated state.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional near infrared cut materials are used, then the cost is reduced, but the heat resistance and light fastness are insufficient
Solution Approach 1:
The patent uses composite materials by combining organic dyes (cyanine, oxonol, squarylium, or croconium compounds) with inorganic metal oxide particles or colloidal silica. This composite structure provides both the near-infrared absorption properties of organic dyes and the heat resistance and light fastness of inorganic materials, resolving the contradiction between cost-effectiveness and reliability.
Solution Approach 2:
The patent changes the physical and chemical parameters of the dye system by using dyes in aggregated states (J-aggregates or H-aggregates) rather than molecularly dispersed states. This aggregation changes the absorption characteristics and improves stability, while the dyes are incorporated into curable compositions that can be cured to form stable films, thereby improving heat resistance and light fastness without requiring expensive glass materials.
2Measurement precision
If conventional near infrared cut materials are used, then the cost is reduced, but the ability to distinguish visible and near infrared regions is insufficient
Solution Approach 1:
The patent applies local quality by selecting specific dye molecules with tailored absorption spectra that target the near-infrared region (700-1100 nm) while maintaining transparency in the visible region. The use of specific compounds (cyanine, oxonol, squarylium, croconium) with defined molecular structures allows precise control over the absorption characteristics, achieving spectral discrimination without requiring expensive broad-spectrum filtering materials.
Solution Approach 2:
The composite structure of organic dyes with inorganic particles provides both the spectral selectivity of the dye molecules and the stability of the inorganic framework, enabling precise discrimination between visible and near-infrared regions at a lower cost than conventional glass-based solutions.
3Reliability
If liquid composition is used as substitute for seal glass, then the cost is reduced, but the heat resistance and light fastness are insufficient
Solution Approach 1:
The patent changes the state of the dye from a simple liquid solution to a cured solid film through the use of curable compositions. The dyes are incorporated into resin systems that can be cured by UV irradiation or other methods, transforming the material from a liquid that would degrade under heat and light into a stable solid film with improved heat resistance and light fastness, while maintaining the cost advantage of using organic dyes instead of glass.
Solution Approach 2:
The curable composition forms a composite material where the organic dye molecules are embedded in a cured resin matrix, providing both the optical properties of the dye and the structural stability of the crosslinked polymer network, thereby achieving improved reliability without excessive device complexity.
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 provides a near infrared cut filter that is excellent in heat resistance and light fastness, allowing for the production of inexpensive solid state imaging devices without the need for expensive glass, while maintaining quality, and is also applicable to plasma display panels.
Implementation Method 1
a near infrared-absorbing dye-containing curable composition... a lake dye having an absorption maximum in the wavelength region of from 700 nm to 1100 nm... ability to cut a needless near infrared light
Data Source
AI summary
A curable composition containing a lake dye having an absorption maximum in the wavelength region of from 700 nm to 1100 nm and a thermosetting compound and/or a photo-setting compound; a solid imaging device installing therein a filter prepared using the curable composition; and a lake dye represented by the following formula (V):wherein L1 represents a methine chain composed of odd number(s) of methine group(s); A1 and A2 are each independently represents an alkyl group having a sulfo group; Y represents a cation necessary to balance a charge and selected from the group consisting of alkali earth metal ions (Mg2+, Ca2+, Ba2+, Sr2+), transition metal ions (Ag+, Fe+, Co2+, Ni2+, Cu2+, Zn2+) and (Al3+).