Touch Sensing Device Parasitic Capacitance Reduction
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Solution Overview
Problem
The existing touch sensing devices with integrated force sensors suffer from reduced signal sensitivity due to interference between the touch sensor and force sensor layers, making it difficult to effectively prevent accidental touches.
Innovation Solution
A touch sensing device and driving method that utilize a plurality of electrodes and a driving circuit to manage parasitic capacitance between the touch sensor and force sensor layers by providing specific driving signals and controlling the electrodes to reduce interference, thereby increasing signal sensitivity and improving accidental touch prevention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the touch sensor layer and force sensor layer are layered on the same area on the display screen, then the device can provide both touch sensing and force sensing functions, but the sensitivity of the signals of the touch sensor and force sensor will be greatly reduced due to interference between the two layers
Solution Approach 1:
The sensing area is divided into multiple electrode groups, with each group containing touch sensing electrodes and force sensing electrodes. By segmenting the sensor layers into distinct electrode groups that can be independently driven, the patent reduces mutual interference while maintaining both touch and force sensing functions in the same area.
Solution Approach 2:
The patent employs periodic driving signals with different frequencies for touch sensing electrodes and force sensing electrodes. The touch sensing electrodes are driven at a first frequency while force sensing electrodes are driven at a second frequency, allowing both sensors to operate simultaneously without signal interference through frequency division multiplexing.
2Productivity
If the touch sensor layer and force sensor layer are driven simultaneously, then the device can perform both touch sensing and force sensing operations, but the parasitic capacitance between the two layers increases causing signal interference
Solution Approach 1:
The patent uses periodic driving signals at different frequencies for simultaneous operation of both sensor layers. The touch sensing electrodes receive driving signals at a first frequency while force sensing electrodes receive driving signals at a second frequency, enabling concurrent operation without parasitic capacitance interference through frequency separation.
Solution Approach 2:
The patent introduces different driving frequencies as an intermediary mechanism to mediate between the touch sensor layer and force sensor layer. By using frequency as the mediating parameter, both layers can be driven simultaneously without their electromagnetic fields interfering with each other through parasitic capacitance.
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 solution effectively reduces parasitic capacitance and enhances the sensitivity of both touch and force sensors, improving the ability to prevent accidental touches by determining touch events based on force sensing results.
Implementation Method 1
a parasitic capacitance between the touch sensor layer and the force sensor layer is reduced by adjusting driving signals of the force sensor layer and the touch sensor layer
Data Source
AI summary
A touch sensing device and a driving method for driving the touch sensing device are provided. The touch sensing device includes a plurality of electrodes and a driving circuit. The electrodes includes a touch sensing electrode and a force sensing electrode. During a touch sensing driving period, the driving circuit provides a first driving signal to one of the touch sensing electrode and the force sensing electrode, provides a second driving signal to another one of the touch sensing electrode and the force sensing electrode or controls the another one of the touch sensing electrode and the force sensing electrode to enter a floating state.