Transparent Auxiliary Electrode for OLED Cathode Resistance
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Solution Overview
Problem
Existing OLED display devices suffer from non-uniform brightness due to high cathode resistance, which is exacerbated by the need for a thin cathode to maintain transparency and aperture ratio.
Innovation Solution
Incorporating a transparent auxiliary electrode over the array substrate, electrically connected to the cathode, reduces cathode resistance without compromising pixel aperture ratio or transparency, by extending to a cathode auxiliary wire and being insulated from the anode, thus addressing the issue of non-uniform brightness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the cathode is made thin to maintain transparency and aperture ratio, then transparency and pixel aperture ratio are improved, but cathode resistance increases causing non-uniform brightness
Solution Approach 1:
The cathode system is segmented into two parts: a thin transparent cathode layer in the pixel display area for maintaining transparency and aperture ratio, and a separate transparent auxiliary electrode in the transparent area for providing low resistance electrical connection. This segmentation allows each part to optimize its function without compromising the other.
Solution Approach 2:
The transparent auxiliary electrode acts as an intermediary component that provides a low-resistance electrical connection path between the power supply and the thin transparent cathode. It mediates between the conflicting requirements of thinness (for transparency) and low resistance (for uniform brightness).
2Area of stationary object
If the cathode is made thin to maintain aperture ratio, then pixel aperture ratio is improved, but cathode resistance increases causing non-uniform brightness
Solution Approach 1:
The cathode system is segmented into two parts: a thin transparent cathode layer in the pixel display area for maintaining transparency and aperture ratio, and a separate transparent auxiliary electrode in the transparent area for providing low resistance electrical connection. This segmentation allows each part to optimize its function without compromising the other.
Solution Approach 2:
The solution moves the low-resistance function to a different spatial dimension - the transparent area surrounding the pixel display area. By placing the auxiliary electrode in this adjacent region and connecting it via conductive wire, the patent resolves the resistance issue without encroaching on the pixel aperture area.
3Reliability
If a transparent auxiliary electrode is added to reduce cathode resistance, then cathode resistance is reduced, but device complexity increases
Solution Approach 1:
The transparent auxiliary electrode serves multiple functions: it provides a low-resistance electrical connection path, maintains transparency to allow light transmission, and can be integrated with the existing transparent area structure. This multi-functionality justifies the additional component by delivering multiple benefits from a single addition.
Solution Approach 2:
The patent uses transparent materials for both the cathode and the auxiliary electrode, maintaining material homogeneity and visual uniformity. This ensures that the auxiliary electrode blends seamlessly with the existing transparent structure, minimizing the perceived complexity increase.
Data Source
AI summary
The disclosure discloses a display panel and a display device. Since at least a part of the transparent areas includes the transparent auxiliary electrode electrically connected with the cathode in the adjacent pixel display area and extends to a top of the cathode auxiliary wire to be electrically connected with the cathode auxiliary wire, i.e., the cathode is electrically connected with the cathode auxiliary wire via the transparent auxiliary electrode, resistance of the cathode is reduced by the use of the transparent auxiliary electrode. Furthermore, since the transparent auxiliary electrode is arranged in a transparent area, neither the size of the at least one pixel display area is reduced, nor the transparent function of the transparent areas is affected.