Display Substrate Common Voltage Line Signal Compensation
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Solution Overview
Problem
In display devices with integrated touch functionality, high-frequency impulse voltage signals used for touch recognition often cause coupling disturbances to other signal lines, leading to inaccurate signal transmission and compromised display quality.
Innovation Solution
A display substrate design that includes a first common voltage line, a second common voltage line, and an integrated circuit. The integrated circuit provides identical display signals to both common voltage lines during the display stage and identical touch signals during the touch stage, ensuring consistent signal transmission without coupling disturbances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If high-frequency impulse voltage signals are used for touch recognition, then touch function is achieved, but coupling disturbances occur to other signal lines leading to inaccurate signal transmission
Solution Approach 1:
A common voltage line compensation circuit is introduced as an intermediary to counteract the coupling disturbances caused by high-frequency touch signals. The compensation circuit receives the same high-frequency impulse voltage signal and generates a compensating signal that cancels out the harmful coupling effects on display signal lines, thereby maintaining signal transmission accuracy while preserving touch functionality
Solution Approach 2:
The harmful coupling effect of high-frequency touch signals on display signal lines is converted into a beneficial compensation mechanism. By intentionally applying the same high-frequency signal to a dedicated common voltage line, the system generates a predictable coupling effect that can be measured and used to create compensation signals, turning the originally harmful interference into a useful reference for signal correction
2Device complexity
If common voltage lines are used for both display and touch signals, then device complexity is reduced, but signal cross-talk occurs between different functional stages
Solution Approach 1:
The common voltage line system is segmented into multiple independent lines, each dedicated to specific functional stages. Display-stage common voltage lines are separated from touch-stage common voltage lines, preventing cross-talk between stages while maintaining the simplicity of using common voltage lines rather than separate dedicated lines for each function
Solution Approach 2:
The system uses time-division multiplexing where common voltage lines are alternately assigned to display stage or touch stage operations. During display stage, common voltage lines provide DC voltages for liquid crystal driving; during touch stage, the same lines provide high-frequency impulse signals for touch sensing, with compensation circuits active only during touch stage to eliminate cross-talk
Data Source
AI summary
A display substrate and a display device are provided. The display substrate has a display area and a peripheral area surrounding the display area. The display substrate includes a first common voltage line, a second common voltage line and an integrated circuit. The first common voltage line is provided in the peripheral area and at least partially surrounds the display area; the second common voltage line is provided in the peripheral area, located on a side of the first common voltage line away from the display area, and at least partially surrounds the display area; the integrated circuit is provided in the peripheral area, and located on a first side of the display area, configured to provide first signals to the first and second common voltage line during a display stage, and provide second signals to the first and second common voltage line during a touch stage.