Organic EL Display Optical Adjusting Layer for Oblique Luminance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Organic EL display devices typically exhibit strong luminance in the front direction but weak luminance in the oblique direction, necessitating improved luminance/visual angle characteristics, and the ability to adjust luminance in both directions based on usage.
Innovation Solution
An organic EL display device with a light emitting unit comprising a first electrode, an organic film with a light emitting layer, and a second electrode, covered by an optical adjusting layer that differs in the number of layers and refractive index in specific areas to enhance light extraction efficiency in the oblique direction while allowing adjustment of luminance in the front direction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a planar light emitting layer is provided on a substrate, then the luminance in the front direction is strong, but the luminance in the oblique direction is weak
Solution Approach 1:
The patent applies local quality by providing different optical adjusting layers in different regions (first area overlapping the light emitting unit and second area adjacent to it) with different numbers of layers, film thicknesses, or refractive indices. This allows independent optimization of light extraction in the oblique direction for specific areas without compromising the overall device structure, thereby improving luminance in the oblique direction while maintaining control over luminance/visual angle characteristics.
Solution Approach 2:
The patent introduces an additional dimensional parameter by varying the optical adjusting layer configuration across different areas (spatial dimension). By making the optical adjusting layer properties position-dependent rather than uniform, the patent achieves improved light extraction in the oblique direction while maintaining the ability to control front direction luminance through appropriate selection of layer parameters in different regions.
2Illumination intensity
If the optical adjusting layer has uniform structure, then manufacturing is simple, but luminance/visual angle characteristics cannot be optimized
Solution Approach 1:
The patent implements local quality by allowing the optical adjusting layer to have different structures (number of layers, film thickness, refractive index) in different areas. The first area overlapping the light emitting unit and the second area adjacent to it can have different optical adjusting layer configurations, enabling targeted optimization of front direction luminance in specific regions while keeping the overall device complexity manageable through localized rather than global modification.
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 improves luminance/visual angle characteristics by optimizing light extraction in the oblique direction and allowing for adjustable luminance in the front direction through the optical adjusting layer's varying thickness and refractive index configurations.
Implementation Method 1
an optical adjusting layer that covers the at least one light emitting unit. The optical adjusting layer in a first area that overlaps the at least one light emitting unit in a planar view and the optical adjusting layer in at least one second area that is adjacent to the first area are different from each other in at least one of a number of layers that the optical adjusting layer includes, a film thickness, and a refractive index
Data Source
AI summary
An organic EL display device includes at least one light emitting unit that includes a first electrode, an organic film that includes a light emitting layer and is provided over the first electrode, and a second electrode that is provided over the organic film and transmits light from the light emitting layer, and an optical adjusting layer that covers the at least one light emitting unit. The optical adjusting layer in a first area that overlaps the at least one light emitting unit in a planar view and the optical adjusting layer in at least one second area that is adjacent to the first area are different from each other in at least one of a number of layers that the optical adjusting layer includes, a film thickness, and a refractive index.