Touch Panel Electrode Layout for Force Sensing and Haptic Feedback
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Solution Overview
Problem
Existing touch panels face challenges in efficiently sensing touch force and touch point due to complex electrode structures and reduced sensitivity, and the integration of haptic functions increases device complexity and cost.
Innovation Solution
A touch panel design utilizing elastic dielectric members and dummy electrodes to sense both touch force and point, and provide haptic feedback without additional actuators, by varying capacitance and vibration through electrode configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If force sensing electrodes and point sensing electrodes are separated, then both touch force and touch point can be sensed, but the electrode structure becomes complicated
Solution Approach 1:
The patent makes the same electrode (first sensing electrode) serve dual functions: detecting both touch force (through capacitance change with dummy electrode) and touch point (through capacitance change with second sensing electrode). This eliminates the need for separate force sensing and point sensing electrode pairs, resolving the contradiction between versatile sensing capability and structural complexity.
2Measurement precision
If force sensing electrodes are decreased in size to improve touch resolution, then touch resolution improves, but the efficiency of sensing touch force is lowered
Solution Approach 1:
The patent segments the sensing functions by introducing a dummy electrode that is electrically connected to the first sensing electrode. This segmentation allows the first sensing electrode to maintain a larger area for force sensing while the intersection with the second sensing electrode provides high-resolution point detection, resolving the contradiction between resolution and sensing efficiency.
3Adaptability or versatility
If additional actuators are added to provide haptic feedback, then haptic function is provided, but the structure of the device is complicated and cost is increased
Solution Approach 1:
The patent makes the existing electrode structures serve dual purposes: touch sensing (both force and point detection) and haptic feedback generation. By applying voltage to the first and second sensing electrodes, the elastic dielectric member vibrates to provide haptic feedback. This eliminates the need for separate actuators, resolving the contradiction between functional versatility and structural complexity.
4Measurement precision
If point sensing electrodes are overlapped to improve touch resolution, then capacitance is maintained at constant value, but the efficiency of sensing touch point is lowered
Solution Approach 1:
The patent introduces an elastic dielectric member as an intermediary between the first and second sensing electrodes. This elastic dielectric member transmits touch force to deform the electrode structure, enabling capacitance change even when electrodes are overlapped, thus maintaining both high touch resolution and efficient touch point sensing.
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
Improves touch resolution and efficiency while simplifying the structure and reducing costs by integrating haptic functionality into the touch panel.
Implementation Method 1
an elastic dielectric member disposed on the first to n-th touch driving electrodes; and first to m-th touch sensing electrode groups disposed on the elastic dielectric member
Implementation Method 2
a touch force is sensed by a change of capacitance (Cm1) in accordance with the decrease of distance in between a pair of force sensing electrodes 12 and 22
Data Source
Figure 1~2
Figure 3~4
Figure 5A~5B
AI summary
Embodiments relate to an apparatus for driving of touch panel (100; 200; 300) comprising: a touch panel (100; 200; 300) including a plurality of touch driving electrodes, an elastic dielectric member (130) provided on the plurality of touch driving electrodes, and a plurality of touch sensing electrode groups provided on the elastic dielectric member and respectively intersected and overlapped with the plurality of touch driving electrodes, wherein each of the touch sensing electrode groups includes a touch sensing electrode and a first dummy electrode being in parallel to each other on the elastic dielectric member; and a touch driving circuit for applying a voltage to the touch driving electrode and applying a reference voltage to at least one touch sensing electrode group in accordance with a haptic mode, wherein the first dummy electrode is connected with the touch sensing electrode in accordance with the haptic mode.