Touch Sensor Electrode Layout for Low-Parasitic-Capacitance Displays
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Solution Overview
Problem
Existing display devices face challenges in optimizing the design of touch sensor electrode layers for efficient touch input detection, particularly in reducing parasitic capacitance and enhancing sensing accuracy while minimizing bezel size.
Innovation Solution
The display device incorporates a sensor electrode layer with specific configurations, including first and second touch electrode groups, connection lines, and dummy electrodes, arranged in a manner that reduces parasitic capacitance and optimizes touch detection, while maintaining a minimal bezel area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the sensor electrode layer uses conventional symmetric design, then the manufacturing is simple, but the parasitic capacitance cannot be minimized and sensing accuracy is reduced
Solution Approach 1:
The patent applies asymmetry by making the first contact electrode have a larger area than the second contact electrode. This asymmetric design allows for optimized electrical characteristics that reduce parasitic capacitance and improve touch sensing accuracy, while still maintaining a manageable structural complexity through the systematic arrangement of electrode groups and connection lines.
Solution Approach 2:
The patent implements local quality by differentiating the areas of contact electrodes based on their specific functional requirements. The first contact electrode connected to the first touch electrode group has a larger area to optimize capacitance coupling, while the second contact electrode has a smaller area, creating locally optimized electrical characteristics throughout the sensor layer.
2Area of stationary object
If the bezel area is reduced, then the display area increases, but the touch sensor electrode layout becomes more constrained
Solution Approach 1:
The patent resolves the bezel size constraint by transitioning from a two-dimensional planar arrangement to a three-dimensional stacked configuration. Multiple touch electrode groups and contact electrodes are arranged in different layers, allowing optimized electrical connections and compact spacing that fit within reduced bezel areas while maintaining manufacturing feasibility.
Solution Approach 2:
The patent applies nesting by placing multiple electrode groups and connection structures in overlapping and stacked configurations. The sensor electrode layer integrates touch electrode groups, contact electrodes, and connection lines in a nested arrangement that maximizes space utilization within the constrained bezel region, enabling larger display areas without compromising manufacturing ease.
3Measurement precision
If parasitic capacitance is minimized through electrode optimization, then sensing accuracy improves, but the electrode structure becomes more complex
Solution Approach 1:
The patent applies segmentation by dividing the sensor electrode layer into multiple distinct touch electrode groups (first touch electrode group, second touch electrode group, etc.) with separate contact electrodes for each group. This segmentation allows independent optimization of each electrode's area and position to minimize parasitic capacitance, while the modular structure keeps the overall design manageable through systematic repetition of optimized units.
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 enhances touch sensitivity and accuracy by minimizing parasitic capacitance and reducing the bezel size, thereby improving the overall user input experience.
Implementation Method 1
A user may input information by pressing or touching the sensing unit while viewing an image displayed on a screen of the display device
Data Source
AI summary
A display device includes: a substrate; a light emitting element layer disposed on the substrate; and a sensor electrode layer disposed on an encapsulation layer and including: a plurality of first touch electrode groups extending along a first direction; a plurality of first touch electrodes, of the plurality of first touch electrode groups, arranged along the first direction; a plurality of second touch electrode groups extending along the second direction and arranged along the first direction; a first contact electrode connected to any one of the plurality of first touch electrodes of any one of the plurality of first touch electrode groups; and a second contact electrode connected to any one of the plurality of first touch electrodes of another of the plurality of first touch electrode groups, and wherein an area of the first contact electrode is greater than an area of the second contact electrode.