Single-Layer Resistive Touch Sensor for Flexible Surfaces
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Solution Overview
Problem
Current touch input technologies are expensive and not suitable for large-scale or flexible surfaces, such as large TVs, due to their reliance on multi-layered, grid-patterned electrodes on rigid glass substrates.
Innovation Solution
A touch-sensing system that injects AC voltage signals into a resistive layer at multiple locations, utilizing a shunting effect and capacitively coupling with a user's body to determine touch locations, eliminating the need for conventional electrode-patterning and enabling a single-layer, roll-to-roll coated, flexible, and scalable solution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multi-layered grid-patterned electrodes on rigid glass substrates are used, then touch sensing accuracy is improved, but manufacturing cost increases and adaptability to flexible surfaces deteriorates
Solution Approach 1:
The patent extracts and eliminates the complex multi-layered electrode structure from the touch sensor design. By removing the grid-patterned electrodes and rigid glass substrate requirements, the invention achieves touch sensing functionality using a simplified single-layer structure that can be manufactured at lower cost while maintaining sensing accuracy through alternative signal processing methods.
Solution Approach 2:
The patent employs flexible thin film structures instead of rigid glass substrates. The touch sensor is implemented using flexible printed circuit boards and thin conductive layers that can conform to various surface geometries, enabling application on flexible displays, curved surfaces, and large-area touch interfaces while reducing manufacturing complexity and cost.
2Measurement precision
If multi-layered grid-patterned electrodes on rigid glass substrates are used, then touch sensing accuracy is improved, but adaptability to flexible and non-flat surfaces deteriorates
Solution Approach 1:
The patent employs flexible thin film structures instead of rigid glass substrates. The touch sensor is implemented using flexible printed circuit boards and thin conductive layers that can conform to various surface geometries, enabling application on flexible displays, curved surfaces, and large-area touch interfaces while reducing manufacturing complexity and cost.
Solution Approach 2:
The patent creates a universal touch sensing platform that can be applied to multiple surface types including flat, curved, and flexible surfaces. The single-layer design with flexible substrate and alternative sensing methodology provides multi-functional adaptability across different display technologies and form factors, eliminating the need for surface-specific sensor designs.
3Difficulty of detecting and measuring
If conventional electrode-patterning is used, then touch detection capability is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent extracts and eliminates the complex multi-layered electrode structure from the touch sensor design. By removing the grid-patterned electrodes and rigid glass substrate requirements, the invention achieves touch sensing functionality using a simplified single-layer structure that can be manufactured at lower cost while maintaining sensing accuracy through alternative signal processing methods.
Solution Approach 2:
The patent replaces the mechanical electrode patterning system with an alternative sensing approach. Instead of relying on physical grid-patterned electrodes, the invention uses capacitive sensing with single-layer conductive structures and processes touch input through software-based signal processing and coordinate transformation algorithms, reducing hardware complexity.
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
The system provides accurate touch location determination, is cost-effective (less than several dollars per square meter), and suitable for non-flat surfaces, allowing easy application to various large-scale and flexible surfaces without increasing manufacturing costs.
Implementation Method 1
The touch sensor may be based on a shunting effect (shunt mode) of an electric field. When approaching the touch sensor, a human body may capacitively couple to the sensor acting as a low-pass filter and thereby increase the electrical impedance of the AC signals.
Implementation Method 2
When approaching the touch sensor, a human body may capacitively couple to the sensor acting as a low-pass filter and thereby increase the electrical impedance of the AC signals.
Implementation Method 3
A touch-sensing system that injects AC voltage signals into a resistive layer at multiple locations, utilizing a shunting effect and capacitively coupling with a user's body to determine touch locations
Data Source
AI summary
In one embodiment, an electrical device may inject one or more first electrical signals into a resistive layer of a touch sensor. The device may receive one or more second electrical signals each corresponding to a first electrical signal injected by a first electrode. The device may determine, based on the one or more second electrical signals, a vector with each element of the vector corresponding to a value associated with a particular second electrical signal. Each element may depend at least on: a relative location between the first electrode injecting the first electrical signal and a second electrode receiving the second electrical signal, the signal frequency, and a user touch location on the touch sensor. The device may determine the user touch location based on the vector using at least one of a lookup table, a curve-fitting coefficient set, or a machine-learning model.