Capacitive Pressure Detection Module Using Elastic Foam
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Solution Overview
Problem
Current touch screen technologies can only detect touch position and not the magnitude of touch pressure, limiting the ability to perform nuanced input operations.
Innovation Solution
A pressure detection module is introduced, comprising electrodes and an elastic foam layer that changes capacitance in response to pressure, allowing for the detection of pressure magnitude through capacitance changes between electrodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a traditional touch screen is used to detect touch position, then the operation is simple and easy to use, but the magnitude of touch pressure cannot be detected
Solution Approach 1:
The patent combines the pressure detection function with the existing touch screen structure by integrating electrodes and elastic foam into the display assembly. The first electrode is formed on the front surface of the display, the elastic foam is positioned behind the display, and the second electrode is formed on the back surface, creating a unified capacitive pressure sensing system that works together with the touch screen without requiring separate pressure sensing components
Solution Approach 2:
The display assembly is designed to serve multiple functions: it acts as both the display component and the pressure detection component. The electrodes and elastic foam structure enable the display to simultaneously present visual information and sense touch pressure magnitude, eliminating the need for separate pressure sensing hardware and achieving multi-functionality within the existing display assembly
2Measurement precision
If electrodes and elastic foam are added to detect pressure, then pressure magnitude can be detected, but the device structure becomes more complex
Solution Approach 1:
The pressure detection module is segmented into distinct functional layers: the first electrode layer on the front surface, the elastic foam layer in the middle, and the second electrode layer on the back surface. This segmentation allows each component to be manufactured and positioned independently, then assembled together, simplifying the manufacturing process while maintaining pressure detection functionality
Solution Approach 2:
The elastic foam serves as an intermediary element between the first and second electrodes. It transmits the mechanical pressure from the touch surface to the electrodes while maintaining electrical insulation, enabling pressure detection without direct contact between the electrodes and the touch interface, thus simplifying the manufacturing and assembly process
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 touch pressure in addition to touch position, enhancing the capability of touch input devices to perform more complex operations by accurately measuring pressure applied on the screen.
Implementation Method 1
A capacitance between the first electrode and the second electrode is changed according to a relative distance change between the reference potential layer and the first and the second electrodes through a transformation of the elastic foam
Implementation Method 2
an elastic foam. The elastic foam is located between the first and the second electrodes and a reference potential layer located apart from the pressure detection module
Data Source
AI summary
A pressure detection module may be provided that includes: a first electrode and a second electrode which are located on an insulation layer; and an elastic foam. The elastic foam is located between the first and the second electrodes and a reference potential layer located apart from the pressure detection module. A capacitance between the first electrode and the second electrode is changed according to a relative distance change between the reference potential layer and the first and the second electrodes through a transformation of the elastic foam. A magnitude of a pressure which causes the elastic foam to be transformed is detected according to the capacitance change.