Self-Capacitance Touch Sensor Routing for Display Parasitic Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Mutual capacitive touch sensors face challenges in accurately recognizing touch positions due to high parasitic capacitance between gate lines and data lines, and require complex line structures for multi-touch recognition.
Innovation Solution
A self-capacitive touch sensor integrated type display device with a configuration of gate lines and data lines crossing over each other, featuring common-touch electrodes and routing wires connected via insulation layers, where the routing wires are overlapped with data lines or gate lines and connected through contact holes, reducing parasitic capacitance and resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a mutual capacitive touch sensor is used, then multi-touch recognition capability is achieved, but parasitic capacitance between gate lines and data lines increases making accurate touch position recognition difficult
Solution Approach 1:
The touch sensing function is segmented into two independent systems: mutual capacitance sensing for multi-touch detection and self-capacitance sensing for precise single-touch detection. This segmentation allows each system to operate optimally for its intended purpose without interference from parasitic capacitance affecting the other system's performance
Solution Approach 2:
A dedicated self-capacitance sensing electrode layer is introduced as an intermediary component between the display and the mutual capacitance sensing layers. This intermediary layer provides a separate sensing path that is immune to parasitic capacitance effects, enabling accurate touch position recognition while preserving multi-touch capability
2Adaptability or versatility
If multiple touch driving lines and touch sensing lines are formed on the common electrode for multi-touch recognition, then multi-touch capability is achieved, but the line structure becomes very complex
Solution Approach 1:
The touch sensing function is segmented into two independent systems: mutual capacitance sensing for multi-touch detection and self-capacitance sensing for precise single-touch detection. This segmentation allows each system to operate optimally for its intended purpose without interference from parasitic capacitance affecting the other system's performance
Solution Approach 2:
The common electrode serves multiple functions: it acts as both the sensing electrode for self-capacitance touch sensing and as part of the mutual capacitance sensing structure. This multi-functionality reduces the need for separate dedicated electrodes, thereby simplifying the overall line structure while maintaining multi-touch capability
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 reduces parasitic capacitance, improves touch sensitivity, and simplifies the routing wire structure, enhancing display performance and touch accuracy by increasing the distance between data lines and routing wires and compensating for step coverage.
Implementation Method 1
a parasitic capacitance between gate line and data lines constituting the display device is very large
Implementation Method 2
changes in voltages generated in sensing nodes defined as crossings of the X-axis electrode lines and the Y-axis electrode lines are sensed
Data Source
AI summary
The present invention relates to a display device having an integral self-capacitance touch sensor, which can enhance a display property and touch performance by reducing parasitic capacitance and resistance, comprising: a plurality of gate lines and a plurality of data lines that are arranged on a first substrate to cross each other; a plurality of pixel electrodes that are connected to the plurality of gate lines and data lines; a plurality of common and touch electrodes, each of which is formed to overlap some of the plurality of pixel electrodes; and a plurality of routing wires connected to the plurality of common and touch electrodes, respectively, to extend parallel to each other, wherein the plurality of routing wires overlap the data lines with a first insulation film therebetween for covering the data lines, or overlap the gate lines that cross the data lines, and the common and touch electrodes are connected to the routing wires, respectively, through contact holes formed through a second insulation film that covers the routing wires.