OLED Light Scattering Spacers for Reflection Reduction
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Solution Overview
Problem
OLED displays suffer from reduced visibility due to external light reflection, which affects black color expression and contrast, primarily caused by the reflection of ambient light from electrodes and metal wires.
Innovation Solution
The implementation of light scattering spacers, such as frustums of pyramids or prisms, integrated with the pixel defining layer, which scatter external light and reduce reflection, improving visibility by maintaining a specific ratio of spacer dimensions to pixel area and being formed from the same material as the pixel defining layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If light scattering spacers are added to suppress external light reflection, then visibility and display characteristics are improved, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The light scattering spacer is integrated with the pixel defining layer, merging two functional elements into a single structure. This reduces device complexity by eliminating separate components while maintaining the light scattering function to suppress external light reflection.
Solution Approach 2:
The pixel defining layer is given multiple functions: it defines the pixel pattern and simultaneously serves as the light scattering spacer. This multi-functional design reduces the number of separate components needed while achieving both pixel definition and light scattering to improve visibility.
2Ease of manufacture
If light scattering spacers are integrated with pixel defining layer using same material, then manufacturing process is simplified, but light scattering efficiency may be reduced
Solution Approach 1:
The pixel defining layer material is given different local properties: in the pixel defining region it provides pattern definition, while in the spacer region it provides light scattering function. This local quality variation allows the same material to serve different functions effectively.
Solution Approach 2:
The shape parameters of the spacer (frustum of pyramid, prism, truncated circular cone, cylinder, hemisphere, or hemispheroid) are optimized to maximize light scattering efficiency. By changing the geometric parameters rather than the material composition, the patent achieves effective light scattering while maintaining manufacturing simplicity.
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 light scattering spacers effectively suppress external light reflection, enhancing the visibility and performance of OLED displays by maintaining a balance between light scattering efficiency and surface consistency.
Implementation Method 1
a light scattering spacer formed on the pixel defining layer
Data Source
AI summary
The present invention relates to an organic light emitting diode (OLED) display and a manufacturing method thereof. The OLED display includes a substrate member that includes a plurality of pixel areas. A thin film transistor (TFT) is formed on the substrate member and includes a gate electrode, a source electrode, and a drain electrode. A planarization layer is formed on the TFT and includes a contact hole through which the drain electrode is partially exposed. A pixel electrode is formed on the planarization layer and is connected to the drain electrode of the TFT through the contact hole. A pixel defining layer is formed on the planarization layer and has a through opening. Light scattering spacers are formed on the pixel defining layer to scatter reflected light and may have various shapes and dimensions.