OLED Common Layer Conductivity Control for Pixel Leakage
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Solution Overview
Problem
Current organic electroluminescent display devices face issues with current leakage between adjacent pixels due to continuous organic films, leading to unwanted light emission, as existing methods fail to effectively address this problem between pixels.
Innovation Solution
A method involving a common layer with reduced electric conductivity between pixel electrodes, achieved by irradiating specific areas with an energy ray, and an insulating layer with a concavo-convex shape to increase electric resistance, preventing current leakage between adjacent pixels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a continuous organic film is used to cover pixel electrodes, then the device structure is simplified and manufacturing is easier, but current leakage occurs between adjacent pixels causing unwanted light emission
Solution Approach 1:
The patent applies local quality by creating a dual-structure organic film system: a continuous common layer for structural integrity and ease of manufacture, and patterned insulating layers with convex portions that provide localized high-resistance regions between adjacent pixels. This allows the organic film to be continuously formed over pixel electrodes while preventing current leakage at pixel boundaries through the insulating layer barriers.
2Device complexity
If the organic film is continuously disposed over adjacent pixels, then manufacturing complexity is reduced, but current leakage causes adjacent pixels to emit light
Solution Approach 1:
The patent introduces an intermediary insulating layer structure with convex portions that are disposed between adjacent pixel electrodes. This insulating layer acts as a mediator that allows the organic film to remain continuous for manufacturing simplicity while blocking current leakage paths between pixels. The convex portions of the insulating layer create localized high-resistance regions that prevent harmful current flow without requiring discontinuous organic film formation.
3Manufacturing precision
If pixel electrodes are miniaturized to bring adjacent pixels closer, then display resolution is improved, but current leakage between pixels increases
Solution Approach 1:
The patent addresses the current leakage problem in miniaturized pixels by transitioning from a two-dimensional planar insulation approach to a three-dimensional structure with insulating layers having convex portions that extend vertically between pixel electrodes. This dimensional change creates effective current blocking paths without increasing lateral pixel spacing, thereby maintaining high display resolution while preventing current leakage between closely-spaced pixels.
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
Prevents current leakage between adjacent pixels, ensuring accurate light emission from individual pixels by reducing conductivity in the common layer and increasing resistance through the insulating layer's design, thereby maintaining pixel isolation.
Implementation Method 1
irradiating the common layer with an energy ray above areas between the respective adjacent pixel electrodes with the avoidance of irradiation above the organic electroluminescent film, in which an electric conductivity of the common layer is reduced above the areas between the respective adjacent pixel electrodes, by irradiation of the energy ray
Data Source
AI summary
A substrate on which a plurality of pixel electrodes are disposed is prepared. An organic electroluminescent film 22 is formed with the inclusion of a common layer that continuously covers the plural pixel electrodes. A common electrode is formed on the organic electroluminescent film. The common layer is irradiated with an energy ray above areas between the respective adjacent pixel electrodes with the avoidance of irradiation above the plural pixel electrodes. An electric conductivity of the common layer is reduced above the areas between the respective adjacent pixel electrodes, by irradiation of the energy ray. With this configuration, a current leakage can be prevented between the adjacent pixels.