OLED Subpixel Segmentation for High Resolution Displays
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Solution Overview
Problem
The resolution of organic light-emitting diode (OLED) displays is limited by the size of the mask plate used in the fine metal mask (FMM) technique for coating luminescent materials, which restricts the ability to further improve pixel density and display resolution.
Innovation Solution
The implementation of a structure where each pixel unit comprises at least four subpixel units, each with three luminescent material layers, where each layer covers two adjacent subpixels and emits light, allowing for smaller subpixel sizes without changing the mask plate size, and varying micro cavity lengths and electrode thicknesses to achieve different colors from each subpixel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the fine metal mask (FMM) technique is used to coat luminescent materials in RGB subpixels, then the display can achieve full color output, but the resolution is limited by the size of the mask plate
Solution Approach 1:
The patent divides each pixel unit into at least four subpixel units (first, second, third, and fourth subpixels) instead of the conventional three RGB subpixels. This segmentation allows the luminescent material layers to cover multiple subpixels while maintaining smaller individual subpixel sizes, thereby improving display resolution without requiring a larger mask plate.
Solution Approach 2:
The patent introduces a fourth subpixel dimension to the conventional RGB three-subpixel structure. By adding this additional spatial dimension (the fourth subpixel), the system can achieve higher pixel density and resolution while using the same mask plate size, as the luminescent material layers are strategically positioned to cover combinations of multiple subpixels.
2Manufacturing precision
If smaller subpixel sizes are used to improve resolution, then the pixel density increases, but the mask plate size would need to be reduced which is not feasible
Solution Approach 1:
By segmenting each pixel unit into four subpixel units and using luminescent material layers that span across multiple subpixels, the patent enables smaller subpixel dimensions within each pixel unit. This segmentation strategy increases pixel density while the mask plate maintains its original size because the luminescent materials are deposited in a pattern that covers multiple smaller subpixel regions.
Solution Approach 2:
The patent merges the coverage function of luminescent material layers across multiple subpixel units. Each luminescent material layer is designed to cover at least two adjacent subpixels, which allows the mask plate to maintain its size while the individual subpixel dimensions are reduced, thereby achieving higher pixel density.
3Adaptability or versatility
If multiple luminescent material layers are used to achieve different colors, then the color gamut improves, but the device structure becomes more complex
Solution Approach 1:
The patent segments the color emission function across multiple luminescent material layers, where each layer is responsible for emitting specific colors (red, green, blue). This segmentation allows for broader color gamut coverage while organizing the complex structure into manageable, functionally distinct layers that can be manufactured using standard processes.
Solution Approach 2:
The luminescent material layers serve multiple functions: they emit specific colors to expand the color gamut, they are positioned to cover multiple subpixels to improve resolution, and they can be manufactured using conventional evaporation and coating techniques. This multi-functionality reduces the need for additional specialized components, thereby managing structural complexity.
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 approach enhances the resolution and color gamut of OLED displays by enabling smaller subpixel sizes and improved color differentiation, resulting in longer service life, lower power consumption, and higher color accuracy.
Implementation Method 1
The light-emitting principle is that when a voltage is applied to the anode 002 and the cathode 004 respectively to form a current, electrons in the cathode 004 and holes in the anode 002 will be combined to form excitons in the light-emitting layer 003, which excite the organic luminescent materials in the light-emitting layer 003 to emit light
Implementation Method 2
varying micro cavity lengths and electrode thicknesses to achieve different colors from each subpixel
Data Source
Figure 1~2c
Figure 2d~3a
Figure 3b~3e
AI summary
The present invention discloses an electroluminescent display and a display device, the electroluminescent display comprising a base substrate and a plurality of pixel units arranged in arrays on the base substrate. Each pixel unit is composed of at least four subpixel units, and each pixel unit comprises at least three luminescent material layers. Each luminescent material layer at least covers two adjacent subpixel units, and only one luminescent material layer in each subpixel unit emits light. Since each luminescent material layer at least covers two adjacent subpixel units, when a luminescent material is evaporated and coated by an evaporation coating process, the subpixel units can be made smaller with the size of the mask plate unchanged, which is helpful for improving the resolution of the display.