Sensor Panel Wiring Layout for Uniform Capacitive Position Detection
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Solution Overview
Problem
The arrangement of connection wires in multiple regions for capacitive position detection devices leads to reduced accuracy due to uneven coupling capacitance and external noise interference, especially with increasing screen sizes and bezel width reductions.
Innovation Solution
The implementation of extension lines or dummy lines that connect to the sensor controller but not directly to sensor electrodes, allowing for differential signal processing to minimize the impact of coupling capacitance and external noise across different regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If connection wires are arranged in multiple regions in a distributed manner, then the device can accommodate more sensor electrodes and larger screen sizes, but the coupling capacitance distribution becomes uneven and position detection accuracy decreases
Solution Approach 1:
The patent introduces extension lines as intermediary elements between the sensor electrodes and connection wires. These extension lines are arranged to extend along the connection wires in the distributed regions, acting as mediators that balance the coupling capacitance distribution. By adding these intermediary extension lines, the system can maintain even capacitance distribution while accommodating more sensor electrodes in a distributed architecture.
Solution Approach 2:
The patent modifies the electrical parameters of the connection path by adding extension lines with specific capacitance values. This changes the total capacitance parameter at each sensor electrode to compensate for the uneven coupling capacitance caused by distributed wire arrangement. The extension lines are designed to provide specific capacitance values that equalize the total capacitance across different sensor electrodes, thereby maintaining position detection accuracy.
2Area of stationary object
If connection wires are arranged in multiple regions in a distributed manner, then the device can support reduced bezel width and larger screen size, but external noise distribution becomes unequal and position derivation accuracy is reduced
Solution Approach 1:
The extension lines serve as intermediary elements that also function as noise compensation mechanisms. By arranging extension lines along the distributed connection wires, the patent creates parallel paths that experience similar external noise. This allows the sensor controller to derive differentials between adjacent sensor electrodes while the extension lines ensure that noise components remain balanced, enabling effective noise cancellation.
Solution Approach 2:
The patent converts the harmful effect of distributed wire arrangement (which causes unequal noise exposure) into a beneficial configuration. By adding extension lines that deliberately create additional capacitance paths, the system ensures that all sensor electrodes in a region experience similar noise conditions. This transforms the disadvantage of distributed arrangement into an opportunity to implement uniform noise exposure, which then can be canceled through differential measurement.
3Measurement precision
If extension lines are added to balance coupling capacitance, then position detection accuracy is maintained in distributed configurations, but device complexity increases
Solution Approach 1:
The patent merges the extension lines with the existing connection wire structure. The extension lines are integrated into the flexible printed circuit board alongside the existing FPC wires, and are combined with the routing lines in the sensor panel. This merging approach allows the capacitance balancing function to be achieved without adding separate, independent components, thereby limiting the increase in device complexity.
Solution Approach 2:
The extension lines perform multiple functions: they balance coupling capacitance distribution, provide additional signal transmission paths, and serve as noise compensation elements. By making these elements multi-functional, the patent reduces the need for separate dedicated components for each function, thereby limiting the increase in device complexity while achieving the capacitance balancing objective.
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 ensures a consistent distribution of coupling capacitance and cancels out external noise, thereby maintaining position detection accuracy even when connection wires are distributed across multiple regions.
Implementation Method 1
coupling capacitance occurs between adjacent ones of the sensor electrodes and between adjacent ones of the connection wires
Implementation Method 2
an external noise is sometimes superimposed upon the downlink signal
Data Source
AI summary
A position detection device includes a first sensor electrode and a second sensor electrode adjacent to the first sensor electrode, first and second connection wires connected to the first and second sensor electrodes, respectively, a sensor controller connected to the connection wires, and a first extension line; and a second extension line. Some of the plurality of connection wires, including the first connection wire, extend at regular intervals in a first region. The connection wires, including the second connection wire, are arranged to extend at regular intervals in a second region different from the first region. The first extension line extends along the second connection wire in the second region and is electrically connected to the first sensor electrode. The second extension line extends along the first connection wire in the first region and is electrically connected to the second sensor electrode.