Touch Sensor Integrating Strain Gauge for Pressure Sensing
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Solution Overview
Problem
Current touch sensors for display devices can only detect touch position but lack the capability to effectively sense touch pressure, which limits their functionality in providing nuanced input experiences.
Innovation Solution
A touch sensor design that incorporates a strain gauge between touch electrodes on the same layer, connected via pressure signal lines and a Wheatstone bridge circuit, allowing for pressure sensing while maintaining touch position detection, with a temperature compensation unit to minimize temperature-related noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a pressure sensor is applied to detect touch pressure, then touch pressure sensing capability is improved, but device complexity increases due to additional sensor layers and integration requirements
Solution Approach 1:
The patent combines the touch electrode layer and pressure sensing function into a single integrated structure. The strain gauge is formed using the same conductive material layers as the touch electrodes, eliminating the need for separate pressure sensor layers and reducing overall device complexity while maintaining pressure sensing capability
Solution Approach 2:
The touch electrode pattern serves dual functions: it acts as both the touch detection electrode and the strain gauge for pressure sensing. By making the touch electrode itself sensitive to strain through its connection to the strain gauge circuit, the structure achieves multi-functionality without adding separate components
2Ease of manufacture
If touch electrodes and strain gauges are arranged on different layers, then manufacturing complexity is reduced, but device thickness and layer structure become more complex
Solution Approach 1:
The patent merges the touch electrode and strain gauge into the same layer by forming the strain gauge using the remaining conductive material after touch electrode patterning. This eliminates the need for separate layers for touch electrodes and strain gauges, simplifying the overall layer structure while maintaining manufacturing feasibility
Solution Approach 2:
The conductive material layer is segmented into different functional regions: some portions form the touch electrodes while other portions form the strain gauge. This segmentation occurs within the same layer, allowing both functions to coexist without requiring additional layers
3Ease of manufacture
If strain gauge is disposed between touch electrodes on the same layer, then manufacturing is simplified, but touch electrode arrangement flexibility is reduced
Solution Approach 1:
The patent applies local quality by assigning different functions to different portions of the same conductive layer. The strain gauge is positioned in specific local regions where it can sense pressure without interfering with the touch electrode patterns, allowing flexible arrangement while maintaining manufacturing simplicity
Solution Approach 2:
The strain gauge acts as an intermediary element that connects to the touch electrodes through the conductive layer. It senses pressure locally and transmits this information through the existing electrode structure, maintaining flexibility in touch electrode arrangement while enabling pressure sensing
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 simultaneous detection of touch position and pressure, enhancing input sensitivity and accuracy, and simplifying manufacturing by integrating touch electrodes and strain gauges on the same layer.
Implementation Method 1
the at least one strain gauge configured to sense a pressure
Implementation Method 2
a Wheatstone bridge circuit unit electrically connected to the strain gauge
Data Source
AI summary
A touch sensor includes: a base layer; a plurality of first touch electrodes arranged on the base layer in a first direction; and at least one strain gauge disposed between the plurality of first touch electrodes, the at least one strain gauge configured to sense a pressure, wherein the plurality of first touch electrodes and the strain gauge are arranged on the same layer.