Graded Functional Layer Convex Lenses OLED Light Extraction
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Solution Overview
Problem
Organic light emitting display devices suffer from low external light extraction efficiency due to the non-directive nature of light emission from the organic light emitting layer, resulting in a low ratio of photons reaching an observer.
Innovation Solution
Incorporation of a graded functional layer with convex lenses made of high refractive film on the encapsulating member, along with a black matrix and color filter layer, to enhance light amplification and prevent color shift by utilizing refractive index differences between low and high refractive films.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If light is emitted uniformly in all directions from the organic light emitting layer, then the viewing angle is wide, but the external light extraction efficiency becomes low
Solution Approach 1:
The patent introduces convex lenses with curved surfaces into the optical path above the organic light emitting layer. These convex lenses have a spherical or aspherical curvature that focuses and directs the emitted light, transforming the uniform omnidirectional emission into directed beams that reach the observer more efficiently, thereby improving external light extraction efficiency without significantly complicating the device structure
Solution Approach 2:
The patent employs an intermediary optical element (convex lens) positioned between the organic light emitting layer and the observer. This intermediary component modifies the light propagation path by refracting and focusing the light, enabling efficient light extraction without requiring direct modification of the light emitting layer itself, thus maintaining device simplicity while improving optical efficiency
2Illumination intensity
If a graded functional layer with convex lenses is added to improve light amplification, then optical efficiency increases, but device structure becomes more complex
Solution Approach 1:
The patent divides the optical management function into segmented components: the organic light emitting layer for light generation, the encapsulating member for protection, and the graded functional layer with convex lenses for light amplification and direction control. This segmentation allows each component to perform its specific function optimally while maintaining overall device modularity and manageable complexity
Solution Approach 2:
The graded functional layer is constructed using composite material structures with varying refractive indices, combining different optical materials in a layered configuration. This composite approach enables precise control of light propagation and amplification through refractive index gradients, achieving high optical efficiency without requiring overly complex single-material solutions
3Illumination intensity
If convex lenses with different refractive indices are used to amplify light, then optical efficiency improves, but manufacturing precision requirements increase
Solution Approach 1:
The patent systematically varies the refractive index parameter across the graded functional layer, creating a controlled gradient from lower to higher refractive indices. This parameter change approach allows optimization of light amplification and direction control while using commercially available materials with known refractive properties, thereby balancing optical performance with manufacturing feasibility and precision requirements
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 optical efficiency and contrast by effectively amplifying light and preventing scattering, thereby enhancing the overall performance of the organic light emitting display device.
Implementation Method 1
a graded functional layer with convex lenses made of high refractive film on the encapsulating member, along with a black matrix and color filter layer, to enhance light amplification and prevent color shift by utilizing refractive index differences between low and high refractive films
Data Source
AI summary
An organic light emitting display device includes a substrate, a plurality of organic light emitting elements disposed on the substrate, the plurality of organic light emitting elements including a first organic light emitting element, a second organic light emitting element and a third organic light emitting element, an encapsulating member encapsulating the plurality of organic light emitting elements, a graded functional layers disposed on the encapsulating member, the graded functional layers including convex lenses disposed on pixel regions, and a black matrix disposed on the graded functional layer.