OLED Subpixel Stacking for High-Resolution Low-Power Color Rendering
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Solution Overview
Problem
Conventional OLED devices face challenges in achieving high resolution and reducing power consumption due to misalignment of fine metal masks, increased power consumption when rendering secondary colors, and the need for additional light emitting layers and materials.
Innovation Solution
The display device employs subpixels with a single light emitting layer and mixed subpixels with overlapping light emitting layers, along with a charge generation layer between them, allowing for the emission of secondary colors without additional materials and reducing the need for multiple fine metal masks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If color light emitting layers are disposed at respective subpixels using a fine metal mask, then color rendering is achieved, but misalignment occurs between the opening of the fine metal mask and the deposition material formation area, reducing manufacturing precision
Solution Approach 1:
The display device divides the screen into multiple subpixels, with each subpixel containing only a single light emitting layer (red, green, or blue). This segmentation eliminates the need for complex multi-layer deposition at each pixel location, thereby avoiding fine metal mask alignment issues while maintaining color rendering capability through spatial arrangement of primary color subpixels.
2Adaptability or versatility
If subpixels with different light emitting layers are simultaneously turned on to emit secondary colors, then color diversity is improved, but power consumption increases
Solution Approach 1:
The invention introduces a vertical stacking dimension by placing multiple light emitting layers at the same subpixel location in the vertical direction, rather than relying solely on horizontal arrangement and simultaneous activation of adjacent subpixels. This allows secondary colors to be generated through vertical layer combination within a single subpixel, reducing the need to simultaneously activate multiple neighboring subpixels and thereby lowering power consumption.
3Adaptability or versatility
If additional light emitting layers are added to emit colors different from red, green and blue, then color variety is improved, but device complexity and material requirements increase
Solution Approach 1:
The invention makes existing light emitting layers (red, green, blue) serve multiple functions by allowing them to be stacked in different combinations within subpixels. The same three light emitting layer types can generate primary colors when individually activated and secondary colors (yellow, cyan, magenta, white) when combined in vertical stacks, eliminating the need for additional light emitting layers while achieving enhanced color variety.
4Reliability
If the opening of the fine metal mask is increased to account for process margins, then manufacturing reliability is improved, but resolution decreases
Solution Approach 1:
By segmenting each pixel into subpixels with single light emitting layers, the required opening size for each deposition process is reduced compared to forming multiple color layers at a single pixel location. This segmentation allows smaller mask openings to be used while maintaining adequate process margins, thereby achieving both manufacturing reliability and high display resolution simultaneously.
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 configuration achieves high resolution and low power consumption by enabling the emission of secondary colors through overlapping light emitting layers, reducing the number of required masks and materials, and optimizing power usage.
Implementation Method 1
The light emitting layer emits light when electrons and holes transported to the light emitting layer are recombined
Data Source
AI summary
A display device achieves a high resolution and a low power consumption through provision of subpixels each including a single light emitting layer and subpixels each including a plurality of overlapping light emitting layers. In the display device, it is also unnecessary to increase the number of expensive fine metal masks even for rendering of various grayscales. In addition, in the display device, different light emitting layers overlap with each other, and a charge generation layer is disposed between the overlapping light emitting layers, and, as such, emission of a secondary color can be achieved without necessity of a material for an additional light emitting layer of the secondary color.