Capacitive Touch Sensor Integrating Auxiliary Electrode for Pressure Detection
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Solution Overview
Problem
Existing touch sensors require separate components to detect both touch position and pressure, leading to increased manufacturing costs and device thickness.
Innovation Solution
A capacitive touch sensor design that integrates first and second electrodes with an auxiliary electrode, along with a touch controller, to calculate touch position and pressure using mutual and self-capacitance variations, eliminating the need for additional pressure detection structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If separate force sensors are used to detect touch pressure, then pressure detection accuracy is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent combines the touch sensor electrodes and force sensing structures into a single integrated device. The first and second electrodes form mutual capacitance for touch detection, while the auxiliary electrode forms capacitance with these electrodes to enable force detection. This merging eliminates the need for separate force sensors, reducing device complexity while maintaining pressure detection capability.
Solution Approach 2:
The touch sensor device performs multiple functions using the same components: it detects both touch position (through mutual capacitance between first and second electrodes) and touch pressure (through capacitance variation between electrodes and auxiliary electrode). This multi-functionality reduces the need for additional specialized components.
2Adaptability or versatility
If separate force sensors are used to detect touch pressure, then pressure detection capability is improved, but manufacturing cost increases
Solution Approach 1:
The patent merges the force sensing function into the existing touch sensor structure by adding an auxiliary electrode that forms capacitance with the first and second electrodes. This integration allows pressure detection without requiring separate force sensor components, thereby reducing manufacturing cost while maintaining pressure detection capability.
3Measurement precision
If additional pressure detection structures are added, then pressure detection accuracy is improved, but device thickness increases
Solution Approach 1:
The patent embeds the force detection functionality within the existing touch sensor layers. The auxiliary electrode is positioned in relation to the first and second electrodes in a nested configuration where the capacitance between them responds to pressure. This nesting approach enables pressure detection without adding significant thickness to the device.
4Device complexity
If a single integrated device detects both touch position and pressure, then device complexity is reduced, but measurement precision may worsen
Solution Approach 1:
The patent segments the detection functions into distinct capacitance measurement modes: mutual capacitance measurement for touch position detection and self-capacitance measurement for force detection. By separating the measurement approaches while using integrated structures, the patent maintains measurement precision for both functions within a single device.
Solution Approach 2:
The touch controller performs periodic switching between different measurement modes - measuring mutual capacitance for position detection and self-capacitance for force detection at different time intervals. This periodic action allows the integrated device to accurately capture both touch position and pressure information without interference between the measurement functions.
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
Enables the detection of both touch position and pressure in a single device, reducing manufacturing costs and thickness by integrating pressure detection into the touch sensor, thereby enhancing user interaction with display devices.
Implementation Method 1
the auxiliary electrode forming a capacitance with the first electrodes and the second electrodes
Implementation Method 2
The insulating member may have elasticity
Implementation Method 3
The capacitance between first and second electrodes and the auxiliary electrode may change as the pressure of the touch increases
Data Source
AI summary
A touch sensor, a display device including the same, and a method for driving a touch sensor that includes a substrate, first connection lines to transmit first output signals, first electrodes disposed on the substrate connected to the first connection lines to transmit the first output signals to the first connection lines, second connection lines to transmit second output signals, second electrodes disposed on the substrate connected to the second connection lines to transmit the second output signals to the second connection lines, an auxiliary electrode spaced apart from the substrate, the auxiliary electrode forming a capacitance with the first electrodes and the second electrodes, and a touch controller connected to the first and second connection lines to receive the first and second output signals from the first and second connection lines, and to calculate a position and a pressure of a touch, using the first and second output signals.