Organic EL Display Panel Recessed Planarizing Layer
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Solution Overview
Problem
In organic electroluminescence (EL) display panels, the uneven drying of liquid ink in the peripheral regions leads to luminance unevenness between pixels due to differences in film thickness, and existing solutions that use dummy pixels to mitigate this issue result in increased device size.
Innovation Solution
An organic EL display panel design with a narrow peripheral region that includes dummy light emitting layers, where the planarizing layer is recessed to allow the dummy light emitting layer to extend inside, helping to maintain uniform ink evaporation and reduce device size by optimizing the layout of banks and ink application.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If dummy pixel regions are provided in the peripheral region to suppress excessive evaporation of liquid ink, then film thickness unevenness is reduced, but device size increases
Solution Approach 1:
The invention applies different structural configurations to different regions: in the light emitting region, the planarizing layer has a first configuration, while in the peripheral region, it has a second configuration that is more effective at suppressing ink evaporation. This localized differentiation allows the peripheral region to perform its evaporation-suppression function without requiring a large area, thus resolving the contradiction between film thickness uniformity and device size.
2Area of stationary object
If the peripheral region width is narrowed to suppress device enlargement, then device size is reduced, but the effectiveness of suppressing ink evaporation may be compromised
Solution Approach 1:
The invention changes the structural parameters of the planarizing layer in the peripheral region (creating a second configuration with different physical characteristics compared to the first configuration in the light emitting region). These parameter changes enable the planarizing layer to provide enhanced evaporation suppression functionality within a narrower width, thus maintaining film thickness uniformity while reducing device size.
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 design effectively reduces film thickness unevenness between pixels while minimizing the width of the peripheral region, thereby preventing device enlargement and enhancing luminance uniformity.
Implementation Method 1
partial pressure of solvent molecules evaporated from applied liquid ink is low in peripheral portions
Data Source
AI summary
An organic EL display panel including a substrate, an element array, a planarizing layer, light emitting layers, and a dummy light emitting layer. The element array is disposed above the substrate and includes a light emitting region and a peripheral region that does not emit light surrounding the light emitting region. The planarizing layer is disposed between the substrate and the element array so as to cover the substrate. The light emitting layers are present in the element array in the light emitting region and include organic light emitting material. The dummy light emitting layer is present in the element array in the peripheral region and includes organic light emitting material. A portion of the planarizing layer below the dummy light emitting layer is recessed, and a lower portion of the dummy light emitting layer extends inside the recessed portion.