OLED Display Substrate Assisting Electrode Parallel IR Drop Reduction
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Solution Overview
Problem
The image quality of OLED display panels is degraded due to large IR drops in the cathode layer, which is often formed using materials like ITO that can damage the luminous layer or have high resistance.
Innovation Solution
A display substrate with an anode layer, a cathode layer, and a luminous layer, where an assisting electrode is insulated and spaced from the anodes, contacting the cathode layer in parallel to reduce total resistance, and spacers divide the substrate into pixel units with different region shapes to form luminous regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the cathode layer is formed by sputtering ITO, then the luminous layer is easily damaged, but luminous efficiency is reduced
Solution Approach 1:
The patent introduces an assisting electrode as an intermediary component between the anode and cathode. This assisting electrode provides an additional current conduction path, reducing the current burden on the cathode layer and thereby reducing damage to the luminous layer while maintaining luminous efficiency
Solution Approach 2:
The patent segments the current conduction path by introducing a separate assisting electrode that works in parallel with the cathode layer. This segmentation allows the current to be distributed through multiple paths, reducing the stress and damage to any single layer including the luminous layer
2Illumination intensity
If the cathode layer is formed by evaporating transparent material with good reflectivity, then reflectivity is improved, but resistance becomes large causing large IR drop
Solution Approach 1:
The patent merges the cathode layer and assisting electrode into a parallel conduction system. The assisting electrode is positioned to work in conjunction with the cathode layer, combining their functions to provide both good reflectivity (through the cathode material) and low resistance (through the additional conduction path of the assisting electrode)
Solution Approach 2:
The patent creates a composite electrode structure by introducing an assisting electrode that works in parallel with the cathode layer. This composite structure combines the reflective properties of the cathode material with the conductive properties of the assisting electrode, achieving both high reflectivity and low resistance
3Ease of manufacture
If the cathode layer has large resistance, then manufacturing is simplified, but image quality is degraded due to large IR drop
Solution Approach 1:
The patent addresses the resistance issue by adding another dimensional element to the electrode system - the assisting electrode positioned in parallel with the cathode layer. This dimensional addition provides an extra current path without complicating the basic cathode fabrication process, maintaining ease of manufacture while improving image quality through reduced IR drop
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
The parallel connection of the assisting electrode and cathode layer reduces IR drop, minimizing signal loss and improving image quality by lowering the resistance of the cathode layer.
Implementation Method 1
the assisting electrode contacting the cathode layer in parallel, such that a total resistance of the assisting electrode and the cathode layer connected in parallel is smaller than a resistance of the cathode layer alone
Data Source
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AI summary
The present invention provides a display substrate, which includes an anode layer, a cathode layer and a luminous layer that is provided between the anode layer and the cathode layer, the anode layer including a plurality of anodes and the luminous layer including a plurality of luminous regions, wherein the display substrate further includes at least one assisting electrode, the assisting electrode being insulated and spaced from the anode, and the assisting electrode contacting with the cathode layer in parallel, such that a total resistance of the assisting electrode and the cathode layer connected in parallel is smaller than a resistance of the cathode layer alone. The IR drop in the cathode of the display substrate provided by the present invention is relatively small, such that loss of electric signals is relatively small in the cathode layer and the assisting electrode, thereby obtaining a relatively higher image quality.