Organic EL Display Recessed Structure and Light Absorption Layer
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Solution Overview
Problem
Organic EL display devices suffer from low viewability under bright light due to reflection of external light, which is not adequately suppressed by existing solutions like circularly polarizing plates, due to scattered and stray light within the elements.
Innovation Solution
An organic electroluminescence device is designed with a base material featuring recessed portions, a reflective layer on the surface of these recesses, a filling layer with optical transparency, and a light absorption layer, partitioning the display region into light emitting and non-emissive areas to reduce external light reflection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a circularly polarizing plate is provided on one face side of the light-emitting portion to prevent reflection, then reflection of external light is reduced, but viewability is not sufficiently improved due to scattered light and stray light in the element
Solution Approach 1:
The light-emitting portion is divided into multiple light-emitting units arranged in an array, with each unit having independent control. This segmentation allows selective activation of specific units to compensate for scattered light and stray light effects, improving overall viewability while maintaining anti-reflection properties
Solution Approach 2:
Different regions of the display element are given different optical properties. The circularly polarizing plate is applied selectively to specific areas, and the light-emitting units have localized control capabilities, allowing optimization of viewability in different zones while maintaining anti-reflection performance
2Object-affected harmful factors
If the light emitting area is reduced to improve viewability, then external light reflection is minimized, but brightness and light utilization efficiency decrease
Solution Approach 1:
The display utilizes periodic scanning of the light-emitting units in a time-division multiplexing manner. By rapidly switching between different units, the perceived brightness is maintained through persistence of vision, allowing reduced light-emitting area while preserving illumination intensity
Solution Approach 2:
The scanning mechanism ensures continuous visual output by rapidly cycling through multiple light-emitting units. This creates the perception of continuous illumination from the entire display area, compensating for the reduced physical light-emitting area and maintaining overall brightness
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 viewability by minimizing external light reflection, enhancing light utilization efficiency and maintaining brightness even with reduced light emitting areas, thus improving the overall performance of the organic EL display.
Implementation Method 1
a reflective layer... The reflective layer is disposed at least on a surface of the recessed portion
Implementation Method 2
a light absorption layer is provided in the non emissive area
Data Source
AI summary
An organic electroluminescence device includes a base material including a recessed portion on one face side, and a light emitting element. The light emitting layer including a reflective layer disposed at least on a surface of the recessed portion, a filling layer that has optical transparency and is filled and disposed in the recessed portion with the reflective layer interposed between the recessed portion and the filling layer, a first electrode that has optical transparency and is disposed at least on an upper-layer side of the filling layer, an organic layer that includes at least a light emitting layer and is disposed on an upper layer of the first electrode, and a second electrode that has optical transparency and is disposed on an upper-layer side of the organic layer. The organic electroluminescence device includes a display region divided into a plurality of unit regions separated from each other. The unit regions each has a light emitting area and a non emissive area that are partitioned. The light emitting area includes the light emitting element, and the non emissive area includes a light absorption layer.