In-cell Touch Display Force Sensing via Capacitance
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Solution Overview
Problem
Current touch-type display devices primarily sense touch position but lack the capability to effectively differentiate between various touch forces, limiting their functionality and user satisfaction.
Innovation Solution
An in-cell touch type display device that incorporates multiple first electrodes embedded in the display panel for touch coordinate sensing and a second electrode positioned outside for touch force sensing, using a touch circuit to apply driving signals and sense touch forces by calculating changes in capacitance between the electrodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If only touch position sensing is implemented, then the device structure remains simple, but the functionality and user satisfaction are limited
Solution Approach 1:
The patent combines touch position sensing and touch force sensing into a single integrated touch panel structure. The first electrodes are embedded within the display panel while the second electrode is positioned on the outer surface, creating a unified capacitive sensing system that simultaneously detects both touch location and applied force without requiring separate sensor layers or components.
Solution Approach 2:
The touch panel serves multiple functions: it acts as both the display interface and the sensing interface. The same capacitive structure that enables touch position detection also enables touch force detection, allowing a single component to provide diverse sensing capabilities (position, force, pressure) that would traditionally require separate specialized sensors.
2Measurement precision
If separate pressure sensors are added to sense touch force, then touch force detection capability is improved, but the device complexity and number of components increase
Solution Approach 1:
The patent merges touch force sensing capability into the existing capacitive touch panel structure by adding a second electrode that works in conjunction with the first electrodes. This integration allows touch force detection to be achieved without adding separate pressure sensor components, layers, or processing systems, thereby maintaining structural simplicity while enhancing sensing precision.
3Productivity
If multiple electrode types are integrated, then simultaneous touch coordinate and force sensing is enabled, but the manufacturing process becomes more complex
Solution Approach 1:
The patent segments the electrode system into two distinct parts: first electrodes embedded within the display panel and a second electrode positioned on the outer surface. This segmentation allows each electrode type to be manufactured and positioned independently using existing display manufacturing techniques, simplifying the integration process compared to creating a fully three-dimensional electrode structure.
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 and efficient sensing of touch coordinates and forces within a single touch driving period, distinguishing between soft and force touches without the need for separate pressure sensors, enhancing user interaction and device functionality.
Implementation Method 1
using a touch circuit to apply driving signals and sense touch forces by calculating changes in capacitance between the electrodes
Data Source
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AI summary
The present disclosure provides an in-cell touch type display device including multiple first electrodes (E1) embedded in a display panel (110), at least one second electrode (E2) positioned outside the display panel (110), and a touch force sensing gap exiting between the multiple first electrodes (E1) and the second electrode (E2) such that a capacitor is formed between the multiple first electrodes (E1) and the second electrode (E2).