OLED Display Anode Width Variation for External Light Reflection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
OLED displays suffer from reduced display visibility due to external light reflection, particularly from metal electrodes with high light reflectivity, which mixes with emitted light.
Innovation Solution
The OLED display design incorporates sub-pixels with anodes of varying widths and openings, where the widths of the anodes and openings are inversely proportional to luminance efficiency, and a black-colored planarization layer is used to absorb external light, minimizing reflection and improving visibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If metal layers with high light reflectivity are used as OLED electrodes, then electrical conductivity is improved, but external light reflection increases causing deteriorated display visibility
Solution Approach 1:
The patent applies local quality by making the anode width vary across different spatial locations within the pixel. Specifically, the anode width is reduced in regions where it would reflect external light toward the viewer, while maintaining sufficient width in other regions to ensure adequate electrical conductivity and light emission. This spatial variation in anode width allows the structure to simultaneously achieve good electrical conductivity and reduced harmful light reflection.
2Illumination intensity
If anode width is increased to improve light emission area, then luminance efficiency is improved, but external light reflection increases
Solution Approach 1:
The patent resolves this contradiction by implementing local quality through spatially varying anode width. The anode is designed with different widths in different regions: wider in areas optimized for light emission to maintain luminance efficiency, and narrower in areas where reduced width minimizes external light reflection. This localized differentiation allows the anode to simultaneously achieve adequate luminance efficiency while reducing harmful reflections.
Solution Approach 2:
The patent applies asymmetry by designing the anode with non-uniform width across the pixel structure. Rather than using a symmetric, uniform width throughout, the anode width varies asymmetrically to optimize different functions in different regions - emission efficiency in some areas and reflection reduction in others. This asymmetric design breaks the trade-off between luminance and reflection.
3Ease of manufacture
If uniform anode width is used across all sub-pixels, then manufacturing simplicity is maintained, but display visibility under external light is deteriorated
Solution Approach 1:
The patent applies local quality by varying the anode width according to the specific requirements of different sub-pixel positions and orientations. This localized optimization reduces external light reflection in a way that is tailored to each sub-pixel's location, thereby improving display visibility without requiring complete redesign of the entire pixel structure, thus maintaining reasonable 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
This configuration reduces external light reflection, enhancing display visibility by optimizing anode and opening dimensions and using a black planarization layer to absorb external light, thereby improving luminous efficiency and outdoor visibility.
Implementation Method 1
a black-colored planarization layer disposed in a lower portion of the first, second, and third anodes
Data Source
AI summary
An organic light emitting diode display includes a pixel having a plurality of sub-pixels. Each of the plurality of sub-pixels includes a first sub-pixel having a first anode and a first organic emission layer, a second sub-pixel having a second anode and a second organic emission layer, and a third sub-pixel having a third anode and a third organic emission layer. The first, second, and third anodes satisfy the following condition:W1+W2<2W3<23Pwhere W1, W2, and W3 respectively denote the width of the first anode, the width of the second anode, and the width of the third anode measured along a direction traversing the first sub-pixel, the second sub-pixel, and the third sub-pixel and where P denotes a width of the pixel measure along the direction traversing the first sub-pixel, the second sub-pixel, and the third sub-pixel.