Matrix Electrode Arrays Reducing Background Capacitance
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Solution Overview
Problem
Existing input devices with matrix electrode arrays face challenges in reducing background capacitance, which affects the accuracy of capacitive sensing and object detection in sensing regions.
Innovation Solution
The input device incorporates a matrix electrode array with transmitter and receiver electrodes arranged in columns, where routing traces for receiver electrodes only overlap receiver electrodes and for transmitter electrodes only overlap transmitter electrodes, and uses an analog front-end to select and sequence receiver electrodes for capacitive measurements, reducing capacitive contributions to the baseline.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If routing traces are disposed underneath sensor electrodes in conventional matrix electrode arrays, then electrical connections are established, but background capacitance increases reducing sensing accuracy
Solution Approach 1:
The patent segments the routing traces into direction-specific groups: first routing traces extend in a first direction and connect to sensor electrodes, while second routing traces extend in a second direction perpendicular to the first. This segmentation allows each trace group to be optimally positioned to minimize capacitive overlap with sensor electrodes, thereby reducing background capacitance while maintaining electrical connectivity.
Solution Approach 2:
The patent introduces a dimensional organization by arranging routing traces in perpendicular directions (first direction and second direction) rather than simply underneath sensor electrodes. This spatial reorganization in multiple dimensions reduces the capacitive coupling between routing traces and sensor electrodes, lowering background capacitance without compromising signal transmission.
2Area of stationary object
If sensor electrodes are arranged in matrix arrays for comprehensive sensing, then sensing coverage is improved, but capacitive interference between electrodes increases
Solution Approach 1:
The patent segments the electrode array into transmitter electrodes and receiver electrodes with dedicated routing trace groups. First routing traces connect to transmitter electrodes while second routing traces connect to receiver electrodes, allowing independent optimization of each trace group's position and orientation to minimize mutual capacitive interference while maintaining comprehensive sensing coverage.
Solution Approach 2:
The patent utilizes perpendicular directional arrangement of routing traces (first direction for transmitter electrodes, second direction for receiver electrodes) to spatially separate capacitive fields. This dimensional separation reduces capacitive coupling and interference between adjacent electrodes in the matrix array, enabling accurate sensing across the entire sensing area.
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 configuration enhances the signal-to-noise ratio and improves the accuracy of object detection by minimizing capacitive interference, allowing for more precise capacitive sensing and object information determination in the sensing region.
Implementation Method 1
matrix electrode array of sensor electrodes that perform transcapacitive or absolute capacitive scans of a sensing region
Implementation Method 2
obtain, using an analog front-end (AFE), a first resulting signal from a first receiver electrode among various receiver electrodes
Data Source
AI summary
An input device may include a matrix electrode array that includes various transmitter electrodes and various receiver electrodes. The transmitter electrodes may be disposed in a first direction. The receiver electrodes may be disposed in a second direction that is substantially parallel with the first direction. The input device may further include a first set of routing traces coupled to the transmitter electrodes and disposed underneath the transmitter electrodes in the first direction. The input device may further include a second set of routing traces coupled to the receiver electrodes and disposed underneath the receiver electrodes in the second direction.