Touch Screen Apparatus with Decoupled Sensing for 3D Input
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Solution Overview
Problem
Existing touch screen technologies face challenges in maintaining precise touch force sensing, especially on curved or bending displays, due to unreliable gap maintenance between touch electrodes, and struggle with high-speed touch report rates due to time division driving methods.
Innovation Solution
A touch screen apparatus with separate first and second touch sensors for capacitance and resistance-based sensing, respectively, utilizing a touch synchronization signal to simultaneously generate 3D touch information, allowing for high-speed reporting and improved sensitivity on various display types.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If gap maintenance members (air layer or elastic member) are used to maintain vertical gap between touch electrodes, then touch force sensing precision is improved, but reliability deteriorates due to repetitiveness and temperature effects
Solution Approach 1:
The patent replaces the mechanical gap maintenance system (air layer or elastic member) with an electromagnetic field-based sensing system. The touch force is detected through changes in electromagnetic capacitance between electrodes rather than maintaining a fixed mechanical gap, eliminating the reliability issues of mechanical gap maintenance while preserving measurement precision.
Solution Approach 2:
The patent changes the sensing parameter from physical gap distance to electrical capacitance. By measuring capacitance changes between touch electrodes, the system can detect touch force without relying on mechanical gap maintenance, thus improving reliability while maintaining measurement precision across various temperatures and repetition cycles.
2Device complexity
If time division driving method is used to sense both touch position and touch force, then device complexity is reduced by sharing touch electrode, but touch report rate deteriorates due to sequential sensing requirements
Solution Approach 1:
The patent implements periodic switching between touch position sensing and touch force sensing operations. By using periodic driving signals with different frequencies for position and force sensing, the system can sequentially activate different sensing modes, improving the touch report rate while maintaining the simplified shared electrode structure.
Solution Approach 2:
The patent introduces dynamic control of electrode activation and sensing modes. The touch electrode's function is dynamically switched between position sensing and force sensing based on timing signals, allowing optimized sensing cycles that improve report rate while maintaining structural simplicity through the shared electrode design.
3Manufacturing precision
If touch electrode is shared by both touch position and touch force sensing, then manufacturing precision requirements are reduced, but signal interference increases due to simultaneous sensing operations
Solution Approach 1:
The patent uses periodic driving signals with distinct time slots for position sensing and force sensing. By activating different electrode combinations at different periods, the system minimizes signal interference while maintaining the benefits of shared electrodes, reducing the need for high manufacturing precision.
Solution Approach 2:
The patent ensures continuous useful action by overlapping the sensing cycles of position and force detection. Through careful timing and signal processing, both sensing functions operate continuously without complete interruption, minimizing dead time while managing signal interference through synchronized operation.
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 precise touch force sensing on flat, curved, or bending displays with high-speed reporting rates, minimizing signal interference noise and enhancing sensitivity by decoupling touch position and force sensing processes.
Implementation Method 1
a first touch panel having a plurality of first touch sensors, wherein a capacitance in each first touch sensor is changed by a user's touch
Implementation Method 2
a second touch panel having a plurality of second touch sensors, wherein a resistance value in each second touch sensor is changed by a user's touch
Data Source
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AI summary
Disclosed is an apparatus for touch screen which is applicable to a flat, curved or bending type display device, and an electronic device comprising the same, wherein the touch screen apparatus includes a touch sensing circuit for outputting 3D touch information by sensing a touch position through a first touch sensor and sensing a touch force through a second touch sensor.