Mutual-Capacitance Touch Panel Bridges for Lower Baseline Capacitance
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Solution Overview
Problem
Existing capacitive touch sensor panels exhibit high effective touch baseline capacitance, which can interfere with accurate detection of touch or proximity events.
Innovation Solution
The implementation of bridge portions in a different layer of the touch sensor panel, which include additional electrodes and expanded areas, to increase the mutual capacitance between the -Tx electrodes and the Rx electrode, thereby reducing the effective touch baseline capacitance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional mutual capacitance touch sensor panels are used, then the touch sensing function is provided, but the effective baseline capacitance is high which interferes with accurate touch detection
Solution Approach 1:
The patent introduces bridge portions in a second layer that are spatially separated from the electrodes in the first layer, creating a three-dimensional capacitive coupling structure. This dimensional separation allows the bridge portions to provide additional capacitance pathways without interfering with the primary touch sensing function, effectively reducing baseline capacitance while maintaining touch detection accuracy
Solution Approach 2:
The bridge portions act as intermediary elements that couple the first and second layer electrodes through capacitive coupling. These bridge portions provide an additional capacitance path that compensates for the harmful baseline capacitance effect, mediating between the drive electrodes and sense electrodes to improve measurement precision
2Object-generated harmful factors
If the distance between -Tx electrode and Rx electrode is reduced to increase mutual capacitance, then baseline capacitance is reduced, but the structural complexity and manufacturing difficulty increase
Solution Approach 1:
Instead of reducing the in-plane distance between -Tx and Rx electrodes which would complicate manufacturing, the patent utilizes the vertical dimension by introducing bridge portions in a second layer. This approach achieves the desired capacitance effect while maintaining simple planar electrode layouts that are easier to manufacture
Solution Approach 2:
The touch sensor is segmented into multiple layers with distinct functions: the first layer contains the primary electrodes for touch sensing, while the second layer contains bridge portions for baseline capacitance compensation. This segmentation allows each layer to be optimized independently for its specific function, simplifying the overall manufacturing 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
This approach effectively reduces the baseline capacitance, enhancing the signal-to-noise ratio for touch detection and improving the accuracy of touch sensing.
Implementation Method 1
increase the mutual capacitance between the -Tx electrodes and the Rx electrode, thereby reducing the effective touch baseline capacitance
Data Source
AI summary
In some examples, a touch sensor panel includes a plurality of touch electrodes in a first layer including a plurality of first drive electrodes along a first axis, a plurality of second drive electrodes along the first axis, and a plurality of sense electrodes formed of sense electrode segments along a second axis. The touch sensor panel includes a plurality of bridges in a second layer. Optionally the plurality of bridges includes one or more portions along the second axis configured to electrically connect the sense electrode segments to form the plurality of sense electrodes, and includes one or more portions along the first axis disposed under the plurality of second drive electrodes.