Scattering Color Filters to Suppress Rainbow Mura in OLED Displays
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Solution Overview
Problem
Organic light emitting displays suffer from rainbow mura due to external light reflection and interference, reducing screen visibility and requiring separate light sources like LCDs.
Innovation Solution
Incorporation of a light scattering layer and color filters with varying concentrations of light scattering particles to mitigate rainbow mura and prevent color mixing, eliminating the need for a polarizer for high-efficiency brightness with low power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a metal material with high reflectivity is used to form the cathode and various lines, then the display device can reflect external light, but rainbow mura is caused by diffraction and interference of the reflected light
Solution Approach 1:
A light scattering layer is introduced as an intermediary component between the metal reflective layers and the external environment. This layer contains light scattering particles that scatter incident light, preventing the regular reflection patterns that cause rainbow mura while maintaining overall light reflection capability.
Solution Approach 2:
The optical parameters of the display device are modified by introducing light scattering particles with specific size distributions and concentrations. These parameter changes alter the light scattering characteristics to mitigate diffraction and interference effects while preserving reflectivity.
2Object-affected harmful factors
If a light scattering layer is added to mitigate rainbow mura, then screen visibility is improved, but device complexity increases
Solution Approach 1:
The light scattering layer is merged with existing display structure components, such as integrating light scattering particles into the color filter layer or combining the scattering function with the encapsulation layer. This merging approach reduces overall structural complexity while maintaining the light scattering function.
Solution Approach 2:
The light scattering layer is designed to serve multiple functions simultaneously: mitigating rainbow mura, enhancing color filter performance, and providing protective characteristics. This multi-functionality reduces the need for separate components, thereby reducing device complexity.
3Object-generated harmful factors
If light scattering particles are included in color filters, then color mixing is prevented, but manufacturing precision requirements increase
Solution Approach 1:
Optimal particle concentration ranges are established for different color filter types, and manufacturing processes are adjusted to maintain these parameters. By defining specific parameter ranges rather than requiring precise single values, manufacturing precision requirements are reduced while still achieving effective color separation.
Solution Approach 2:
Different light scattering particle concentrations are applied to different color filter regions based on local requirements. This localized approach allows optimization for each color (red, green, blue) independently, reducing the need for uniform high-precision control across the entire display.
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 effectively reduces rainbow mura and color mixing while enhancing display reliability and efficiency by optimizing the display process without a polarizer.
Implementation Method 1
At least one of the plurality of color filters can include light scattering particles for scattering light incident thereon
Data Source
AI summary
A display can include a substrate, a plurality of light emitting elements disposed on the substrate, and a plurality of color filters disposed to overlap the plurality of light emitting elements. At least one of the plurality of color filters can include light scattering particles for scattering light incident thereon.