OLED Touch Electrodes Reduce Coupling Capacitance
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Solution Overview
Problem
The integration of a touch unit within the organic light-emitting display panel leads to coupling capacitors with cathodes, affecting touch performance and reducing detection precision due to the formation of capacitors between touch driving and detecting electrodes.
Innovation Solution
The organic light-emitting display panel design includes a first electrode layer with stripe-shaped first electrodes and alternately arranged first and second touch electrodes, both disposed in the same layer, reducing coupling capacitance with the cathode layer by configuring them in a capacitive structure with an insulating medium, thereby improving touch detection accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If the touch unit is disposed inside the organic light-emitting display panel to reduce thickness, then the overall thickness is reduced, but coupling capacitors are formed between touch electrodes and cathodes which reduces touch detection precision
Solution Approach 1:
An insulating medium layer is introduced as an intermediary between the touch electrodes and the cathode layer. This intermediate layer prevents direct electrical coupling while maintaining the thin-profile structure, thereby preserving touch detection precision despite the internal placement of touch electrodes
Solution Approach 2:
The display panel is segmented into distinct functional layers with clear spatial separation. Touch electrodes are placed in specific layers (such as the hole transport layer or electron transport layer) rather than directly overlapping with the cathode, creating segmented functional zones that reduce parasitic capacitance while maintaining overall panel thickness
2Device complexity
If touch driving and detecting electrodes are arranged in the same layer to simplify structure, then device complexity is reduced, but coupling capacitors are formed which affects touch performance
Solution Approach 1:
Different regions of the same layer are assigned different functional qualities. Within the same layer, touch driving electrodes and detecting electrodes are spatially separated and oriented in different directions (e.g., x-axis vs y-axis), allowing them to coexist in the same layer without forming harmful coupling capacitors, thus maintaining both structural simplicity and touch performance
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 minimizes the influence of cathodes on touch performance, enhancing the precision of touch detection by reducing coupling capacitance and allowing for more accurate determination of touched coordinates.
Implementation Method 1
an organic light-emitting layer configured between the array substrate and the transparent cover plate
Data Source
AI summary
An organic light-emitting display panel and an organic light-emitting display device are provided. The organic light-emitting display panel comprises an array substrate; a transparent cover plate; and an organic light-emitting layer configured between the array substrate and the transparent cover plate. The organic light-emitting layer comprises: a first electrode layer including a plurality of first electrodes, a plurality of first touch electrodes extending in a first direction, arranged in a second direction, and disposed in a same layer as the first electrode layer, and a plurality of second touch electrodes.