Patterned Color Conversion Film Scattering Particle Optimization
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Solution Overview
Problem
Conventional color filters in display devices face challenges with incomplete backlight absorption, poor viewing angle characteristics, and decreased light extraction rates when replaced by patterned color conversion films, particularly due to thickness limitations and light entering the waveguide mode.
Innovation Solution
A patterned color conversion film incorporating scattering particles with specific size and volume concentration ranges, dispersed in a medium with a refractive index between 1.4 and 1.7, to enhance backlight absorption and light extraction without increasing film thickness, addressing issues of color shift and light extraction efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the thickness of the patterned color conversion film is increased to completely absorb and convert the backlight, then the backlight utilization rate is improved, but material waste increases and process complexity increases
Solution Approach 1:
The patent introduces scattering particles with specific size parameters (0.1-10 μm) and controls their volume concentration (1-50%) to optimize light scattering effects. This parameter optimization enables complete backlight absorption at reduced film thickness, resolving the contradiction between utilization rate and process complexity
Solution Approach 2:
The patent creates a composite structure by dispersing scattering particles (such as TiO2, SiO2, or polystyrene) within the color conversion film matrix. This composite approach enhances light scattering and absorption efficiency, achieving high backlight utilization without increasing thickness or process complexity
2Use of energy by moving object
If the thickness of the patterned color conversion film is increased to completely absorb and convert the backlight, then the backlight utilization rate is improved, but the film thickness increases
Solution Approach 1:
By optimizing the size parameters of scattering particles (0.1-10 μm) and their concentration (1-50%), the patent achieves maximum light scattering efficiency at minimal film thickness, eliminating the need to increase thickness for improved utilization
Solution Approach 2:
Scattering particles serve as intermediary elements that enhance light-matter interaction within the film. These particles scatter incident light multiple times, increasing the effective optical path length without increasing physical thickness, thereby achieving complete absorption at reduced thickness
3Reliability
If the patterned color conversion film is used as color filters, then the light extraction rate may be decreased due to absorption by black matrix, but this can be improved by optimizing film structure
Solution Approach 1:
The patent applies scattering particles selectively within the color conversion regions, creating local optical enhancement zones. This localized approach improves light extraction in critical areas without affecting the overall film structure or requiring changes to the black matrix
Solution Approach 2:
The patent converts the potentially harmful effect of light entering waveguide modes by using scattering particles to redirect this trapped light back into extractable paths. The scattering particles transform waveguide-mode light into propagating modes that can escape the film, turning a loss mechanism into a beneficial extraction enhancement
4Manufacturing precision
If conventional color filters are replaced with patterned color conversion films, then color accuracy may be improved, but viewing angle characteristics deteriorate due to incomplete backlight absorption
Solution Approach 1:
The patent optimizes scattering particle size (0.1-10 μm) and concentration (1-50%) to achieve uniform light scattering across different viewing angles. This parameter optimization ensures complete backlight absorption and consistent color output, resolving the viewing angle issue while maintaining color accuracy
Solution Approach 2:
The uniform dispersion of scattering particles throughout the color conversion film creates homogeneous light scattering properties. This homogeneity ensures consistent optical performance across all viewing angles, eliminating the viewing angle dependence that plagues conventional color filters
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 achieves high backlight utilization and light extraction rates, along with improved viewing angle uniformity, by diffusing incident light and extracting light from the waveguide mode, thus overcoming the limitations of conventional color filters.
Implementation Method 1
the absorption efficiency of backlight of a film is proportional to the paths that the backlight travelling therein... most of the light emitting from the quantum dots may enter into a waveguide mode... the light in the waveguide mode is finally absorbed by a separator
Implementation Method 2
quantum dot/polymer complex has been widely applied to the backlight and lighting fields... complexes containing quantum dots with different light-emitting wavelength can convert single wavelength light emitting from a backlight source into light with various wavelengths
Data Source
AI summary
A patterned color conversion film and a display device using the same are disclosed. The patterned color conversion film of the present invention comprises: a separator with plural openings; and plural pixel units disposed in the openings respectively, each pixel unit respectively comprising: a medium and scattering particles dispersed therein. Herein, at least one of the plural pixel units comprises quantum dots having the scattering particles sized of between 0.05 and 1 μm when a volume concentration of the quantum dots is in a range more than or equal to 5% and less than or equal to 80%, or having the scattering particles sized of between 0.2 and 2 μm when the volume concentration of the quantum dots is in a range less than 5% and more than or equal to 0%.