Color Conversion Film Solvent Control for Photobleaching
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Solution Overview
Problem
Color conversion films used in displays suffer from photobleaching due to exposure to oxygen and moisture, leading to reduced durability and light emission efficiency when driven by a backlight light source.
Innovation Solution
A color conversion film is manufactured with a thermoplastic resin, organic fluorescent dye, and a controlled amount of solvent (0.0001 to 0.1 part by weight) to improve durability, featuring a base film with a color conversion layer that includes light diffusion particles and a barrier film to prevent moisture and oxygen exposure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a color conversion film is manufactured by dissolving organic fluorescent dye and binder in organic solvent, coating and drying the solution, then the manufacturing process is simple and cost-effective, but the remaining solvent causes photobleaching phenomenon when exposed to oxygen and moisture, reducing film durability
Solution Approach 1:
The patent applies parameter changes by precisely controlling the solvent content to 0.0001-0.1 parts by weight based on 100 parts by weight of the color conversion layer. This quantitative parameter control resolves the contradiction by maintaining enough solvent for manufacturing processability while limiting it to prevent photobleaching, thus achieving both ease of manufacture and film durability
Solution Approach 2:
The patent uses composite materials by combining thermoplastic resin, organic fluorescent dye, and controlled amounts of solvent to form a color conversion layer. This composite structure allows the material to exhibit both manufacturability (through resin-solvent interaction) and durability (through limited solvent content preventing photobleaching)
2Reliability
If the solvent content in the color conversion layer is reduced to prevent photobleaching, then film durability is improved, but the manufacturing process becomes more difficult to control
Solution Approach 1:
The patent establishes a specific parameter range (0.0001-0.1 parts by weight of solvent per 100 parts by weight of color conversion layer) that balances durability and manufacturability. This precise parameter definition provides clear manufacturing targets, making the process controllable while achieving the desired low solvent content for photobleaching prevention
Solution Approach 2:
The patent implements feedback control by measuring and adjusting solvent content to maintain it within the specified range. This feedback mechanism ensures that manufacturing precision is achieved by continuously monitoring and correcting solvent levels, thereby preventing photobleaching while maintaining process control
3Illumination intensity
If the color conversion film thickness is reduced to improve display performance, then brightness and efficiency are enhanced, but the film becomes more susceptible to photobleaching and durability issues
Solution Approach 1:
The patent changes the solvent content parameter to extremely low levels (0.0001-0.1 parts by weight), which prevents photobleaching reactions even in thin films. This parameter change allows the film to maintain both high brightness (through adequate thickness) and high durability (through photobleaching prevention) simultaneously
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 film exhibits improved durability and reduced light emission decrease over time, maintaining high brightness and efficiency even with a smaller thickness, outperforming traditional films by minimizing solvent content and using light diffusion particles for enhanced brightness.
Implementation Method 1
an organic fluorescent dye dispersed in the thermoplastic resin
Implementation Method 2
drying the solution in order to apply the organic fluorescent dye to a display
Data Source
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AI summary
The present specification relates to a color conversion film, and a backlight unit and a display device, including the same.