Light Extraction Curved Surfaces Display Brightness
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Solution Overview
Problem
Light emitting display devices face issues with low light extraction efficiency due to total reflection at interfaces, leading to reduced brightness and increased power consumption, as well as degradation of black visibility characteristics caused by external light reflection.
Innovation Solution
Incorporating a light extraction portion with curved surfaces and a light guide portion featuring refractive patterns that overlap concave and convex structures, which redirects and disperses reflected light to enhance extraction efficiency and reduce external light reflection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a planarization layer with light extraction portions (concave and convex structures) is introduced to improve light extraction efficiency, then light extraction efficiency and brightness are improved, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent introduces curved surfaces (concave and convex portions) in the light extraction portion of the planarization layer. These curved structures modify the light path through refraction and reflection, extracting trapped light that would otherwise be lost to total internal reflection, thereby improving brightness without requiring complex additional components
Solution Approach 2:
The patent adds vertical dimensionality to the light extraction interface by creating concave and convex portions that extend into the thickness direction of the planarization layer. This three-dimensional structuring allows light extraction from multiple angles and depths, improving overall light extraction efficiency beyond what flat surfaces can achieve
2Loss of energy
If light extraction portions with curved surfaces are added to improve light extraction, then light extraction efficiency improves, but manufacturing precision requirements increase
Solution Approach 1:
The patent optimizes specific parameters of the curved surfaces, including the depth, width, and spacing of concave and convex portions, to achieve effective light extraction. By carefully controlling these geometric parameters within practical manufacturing tolerances, the patent balances light extraction performance with manufacturability
3Object-affected harmful factors
If a light guide portion with refraction patterns is introduced to reduce external light reflection, then black visibility characteristics improve, but device complexity increases
Solution Approach 1:
The patent introduces a light guide portion with refraction patterns as an intermediary layer between the light emitting device and the external environment. This light guide mediates the interaction with external light by refracting incident light away from the viewing direction, reducing reflections that would degrade black visibility, while maintaining a relatively simple overall device architecture
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 significantly improves light extraction efficiency and maintains high brightness while achieving real black visibility by minimizing rainbow patterns and diffraction dispersion, thus reducing power consumption and enhancing display performance.
Implementation Method 1
since some of the light emitted from the emitting device layer is not emitted to the outside due to a total reflection at the interface between the emitting device layer and the electrode and/or a total reflection at the interface between the substrate and the air layer
Implementation Method 2
a light guide portion on the light emitting surface, the light guide portion including a light refraction pattern portion
Implementation Method 3
degradation of black visibility characteristics caused by a reflection of external light
Data Source
AI summary
A light emitting display device is disclosed. The light emitting device comprises a substrate including a plurality of pixels having a light emitting area, a light extraction portion including a curved portion in the light emitting area, a light emitting device layer over the light extraction portion and configured to emit light to a light emitting surface, and a light guide portion on the light emitting surface and including a light refraction pattern portion.