Capacitive Stylus Electrode Layout for Reduced Signal Coupling
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Solution Overview
Problem
Capacitive styluses face accuracy issues due to coupling between transmitting electrodes, affecting location detection and inclination measurement, which compromises writing precision and overall performance.
Innovation Solution
A stylus design with a first electrode in the tip and a second electrode on the inner wall of the stylus rod, increasing the distance between them to reduce coupling, enhancing location and inclination detection accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If two transmitting electrodes are disposed close together in the stylus tip, then the device structure is compact, but coupling occurs between the electrodes affecting writing accuracy
Solution Approach 1:
The patent extends the electrode arrangement from a two-dimensional planar configuration to a three-dimensional spatial arrangement by positioning electrodes at different longitudinal positions along the stylus rod. The first transmitting electrode is located in the stylus tip while the second transmitting electrode is positioned higher on the stylus rod, creating vertical separation that reduces electromagnetic coupling while maintaining compact lateral dimensions.
Solution Approach 2:
The patent divides the electrode system into separate functional segments: the first transmitting electrode in the stylus tip for location detection, the second transmitting electrode higher on the rod for inclination measurement, and a receiving electrode positioned separately. This segmentation isolates the electrode functions and reduces mutual interference between them.
2Device complexity
If two transmitting electrodes are disposed close together in the stylus tip, then the device structure is compact, but coupling occurs between the electrodes affecting use performance
Solution Approach 1:
The patent resolves the contradiction by transitioning from a simple two-dimensional planar electrode layout to a three-dimensional configuration where electrodes are distributed along the longitudinal axis of the stylus. This spatial distribution reduces electromagnetic coupling and improves reliability while maintaining structural simplicity.
Solution Approach 2:
The patent introduces a non-conductive material filling the space between the first transmitting electrode and the second transmitting electrode. This intermediary material acts as an electromagnetic shield, reducing coupling between the electrodes and improving signal reliability without adding structural complexity.
3Measurement precision
If transmitting electrodes are isolated and shielded with spacing, then coupling is reduced improving accuracy, but the device structure becomes more complex
Solution Approach 1:
The patent combines multiple functions into integrated electrode structures. The first transmitting electrode serves both as a location detection element and as part of the inclination measurement system when combined with the second transmitting electrode. The receiving electrode also participates in multiple detection functions, reducing the need for separate dedicated components and simplifying the overall structure.
Solution Approach 2:
The patent implements multi-functional electrodes where the same electrode structures serve multiple purposes. The transmitting electrodes are used for both location detection and inclination measurement, and the receiving electrode participates in various signal reception functions. This universality reduces the total number of components needed while maintaining high measurement precision.
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 the accuracy of location and inclination measurement, leading to better writing precision and performance by minimizing electromagnetic interference between the electrodes.
Implementation Method 1
The first electrode is configured to transmit a first signal to an electronic device, and the second electrode is configured to transmit a second signal to the electronic device
Implementation Method 2
a transmitting electrode and a receiving electrode are usually disposed in the capacitive stylus. The transmitting electrode is configured to transmit a signal to a touchscreen, and the receiving electrode is configured to receive a signal sent by the touchscreen
Data Source
Figure 1~2A
Figure 2B
Figure 3~4
AI summary
Embodiments of this application provide a stylus and an electronic device component. The stylus includes a stylus rod and a detachable stylus tip at one end of the stylus rod, and further includes a first electrode, a second electrode, a first circuit board, and a second circuit board. The first electrode is disposed in the stylus tip, the first electrode is connected to the first circuit board, and the first circuit board is electrically connected to the second circuit board. The second electrode is disposed on an inner wall of the stylus rod, or the second electrode is disposed on a fastener in the stylus rod, and the second electrode is electrically connected to the second circuit board or the first circuit board. This increases a distance between the first electrode and the second electrode, and reduces coupling between the first electrode and the second electrode. The stylus in embodiments of this application resolves a problem that writing accuracy of the stylus is reduced because the two electrodes in the stylus are easily coupled.