Stacked OLED Layers With Wavelength Conversion for Full-Color Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current organic light emitting display devices face challenges in achieving full color display with efficient light emission and high color reproducibility, particularly in converting blue light to green light, due to variations in light conversion efficiency across different regions.
Innovation Solution
The display device incorporates a structure with multiple light emitting layers and charge generating layers, along with wavelength conversion patterns and filters, to ensure consistent emission of red, green, and blue lights across regions, utilizing quantum dots and scatterers to enhance color conversion efficiency and reduce alignment tolerances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single organic light emitting layer is used, then the device structure is simple, but full color display with high color reproducibility cannot be achieved
Solution Approach 1:
The organic light emitting layer is divided into multiple sub-layers, each emitting a different color (blue, green, red). This segmentation allows each layer to be optimized for specific wavelength emission, enabling full color display with high color reproducibility while maintaining a relatively simple overall device structure.
Solution Approach 2:
Different regions of the light emitting layer have different emission characteristics. The blue light emitting layer, green light emitting layer, and red light emitting layer are positioned in specific regions to achieve uniform color emission across the display area, improving color reproducibility without significantly increasing device complexity.
2Manufacturing precision
If wavelength conversion patterns are added to convert blue light to green light, then color conversion efficiency is improved, but device complexity increases
Solution Approach 1:
The wavelength conversion pattern is integrated with the organic light emitting layer structure. The pattern is formed within or adjacent to the light emitting layer, combining the light emission function and wavelength conversion function in a single integrated structure, thereby improving color conversion efficiency without significantly increasing device complexity.
Solution Approach 2:
The wavelength conversion pattern acts as an intermediary between the blue light emitting layer and the green light emission requirement. It converts blue light to green light through optical conversion, enabling efficient color conversion while maintaining a relatively simple device structure compared to using separate conversion components.
3Manufacturing precision
If multiple light emitting layers are stacked, then color reproducibility is improved, but light emission uniformity across regions becomes difficult to maintain
Solution Approach 1:
Each light emitting layer is positioned in specific regions with optimized local characteristics. The blue light emitting layer, green light emitting layer, and red light emitting layer are arranged to ensure uniform light emission across the display area, maintaining emission uniformity while achieving high color reproducibility through the multi-layer structure.
4Productivity
If charge generating layers are positioned between light emitting layers, then light emission efficiency is improved, but device complexity increases
Solution Approach 1:
The charge generating layer is integrated between the light emitting layers, combining the charge generation function with the light emission structure. This integration improves light emission efficiency by ensuring proper charge supply to each emitting layer while maintaining a compact and relatively simple overall device structure.
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 improves luminance and color reproducibility by ensuring uniform light emission and compensating for differences in light amounts across colors, resulting in enhanced display quality.
Implementation Method 1
a first wavelength conversion pattern disposed on the common electrode, overlapping the first organic layer, and wavelength-converting light of a first color into light of a second color different from the first color
Implementation Method 2
Electrons and holes provided from the two electrodes are recombined in the organic light emitting layer to generate excitons, and the generated excitons are shifted from the excited state to the ground state to emit light
Implementation Method 3
utilizing quantum dots and scatterers to enhance color conversion efficiency
Data Source
AI summary
A display device includes first and second light emitting regions; first and second pixel electrodes in the first and second light emitting regions, respectively; a first organic layer in the first light emitting region, including first and second light emitting layers; a second organic layer in the second light emitting region, including a third light emitting layer; a common electrode on the first and second organic layers; a wavelength conversion pattern on the common electrode, overlapping the first organic layer, and wavelength-converting light of a first color into light of a second color, different from the first color; and a light transmitting pattern on the common electrode, overlapping the second organic layer. The third light emitting layer and one of the first and second light emitting layers emit light of the first color, and another one of the first and second light emitting layers emits light of the second color.