Capacitive Touch Sensing Device Noise Reduction via Segmented Electrodes
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Solution Overview
Problem
Conventional capacitive touch sensing devices face errors due to noise coupling from surrounding environments, particularly when integrated with display devices, which affects the accuracy of cross-capacitance measurements.
Innovation Solution
The capacitive touch sensing device employs a sensing array with independently controlled transmitting electrodes and receiving electrodes, where each row of transmitting electrodes is divided into groups coupled to separate signal lines, allowing for differential capacitance measurements to isolate and eliminate noise from display electrodes by using predetermined voltage levels and signal polarities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the sensing device is integrated with a display device, then the functionality and compactness are improved, but noise coupling onto the sensing electrodes from display electrodes increases, degrading measurement precision
Solution Approach 1:
The sensing electrodes are divided into multiple segments along each row, with each segment independently controllable. This segmentation allows selective activation of specific electrode segments to perform differential measurements that cancel out noise from display electrodes, thereby maintaining measurement precision while enabling integration with display devices.
Solution Approach 2:
The patent applies different voltage levels (first voltage level and second voltage level) to different segments of sensing electrodes. By changing the electrical parameters (voltage levels) of adjacent electrode segments, the system can perform differential capacitance measurements that eliminate common-mode noise from display electrodes, thus improving measurement accuracy in integrated systems.
2Device complexity
If all diamond shapes on the same horizontal row are belonged to the same horizontal sensing electrode and are not controlled independently, then the device complexity is reduced, but the types of cross-capacitance measurement methods are reduced
Solution Approach 1:
Each horizontal row of sensing electrodes is divided into multiple independently controllable segments. This segmentation enables multiple measurement methods by allowing different combinations of segments to be activated simultaneously or sequentially, increasing measurement versatility without significantly increasing overall device complexity through systematic control schemes.
Solution Approach 2:
The system dynamically controls the voltage levels of different electrode segments based on the measurement requirements. By dynamically switching between different voltage configurations (e.g., adjacent segment differential measurement, non-adjacent segment measurement), the system can adaptively select appropriate measurement methods for different sensing scenarios.
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 effectively reduces noise interference, enhancing the accuracy of capacitance measurements and improving the reliability of touch sensing in integrated systems.
Implementation Method 1
A capacitance Cpar is formed between the horizontal sensing electrode T10 and a voltage terminal Vcom, and another capacitance is formed between the vertical sensing electrode R10 and the voltage terminal Vcom. When a grounded object 10 approaches the crossing point of the horizontal sensing electrode T10 and the vertical sensing electrode R10, the crossing capacitance Ccross between the horizontal sensing electrode T10 and the vertical sensing electrode R10 is decreased.
Data Source
AI summary
A sensing device is provided. The sensing device includes at least one first receiving electrode, a plurality of first electrodes, and at least one second electrode. The first receiving electrode extends in a first direction. The first electrodes are connected electrically by a first signal line. The width of each first electrode is larger than a width of the first signal line. The first signal line passes through the first electrodes. The first signal line and the first electrodes are overlapped. The first electrodes have a first voltage level. The second electrode has a second voltage level. The first electrodes and the second electrode are disposed on the same row which extends in a second direction intersecting the first direction. The first voltage level is different from the second voltage level. The first signal line crosses the first receiving electrode and the second electrode.