Touch Chip Synchronization for Display Noise Cancellation
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Solution Overview
Problem
The close proximity of conductive electrodes in display and touch detection systems in portable devices leads to increased capacitance and interference, affecting touch detection sensitivity due to display system noise.
Innovation Solution
A synchronization module associates touch driving with display control signals, enabling differential processing of touch sensor outputs to cancel or reduce display system interference, improving signal-to-noise ratio and sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the distance between conductive electrodes in display system and touch detection system is reduced to achieve lightness and thinness, then the device achieves lighter weight and thinner structure, but the capacitance value increases causing display system interference to greatly affect touch detection sensitivity
Solution Approach 1:
The patent applies preliminary action by performing touch detection before the display system generates interference signals. The touch detection is conducted in advance during a period when the display system is not actively driving, thereby capturing touch information before display noise contaminates the measurement, thus resolving the contradiction between reduced distance and maintained sensitivity
Solution Approach 2:
The patent converts the harmful display system interference into a beneficial timing reference. By synchronizing touch detection with the display system's driving cycle, the interference periods are used to identify optimal detection windows, transforming the harmful noise into a useful synchronization mechanism that maintains detection accuracy despite reduced electrode distance
2Productivity
If touch detection is performed during display system driving period, then touch detection can be continuous, but display system noise greatly affects touch detection sensitivity
Solution Approach 1:
The patent implements periodic action by conducting touch detection during specific periods of the display system's driving cycle. Instead of continuous detection, the system performs detection in defined time windows synchronized with display refresh cycles, alternating between detection periods and display driving periods, thus maintaining continuity while avoiding noise interference
Solution Approach 2:
The patent performs touch detection in advance during periods when the display system is not driving, capturing touch information before interference occurs. This preliminary detection action ensures touch continuity is maintained while avoiding the harmful noise periods of display system operation
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
The method enhances touch detection sensitivity by synchronizing touch driving with display control signals, allowing differential processing to mitigate interference, thereby improving the signal-to-noise ratio and overall touch detection performance.
Implementation Method 1
since some conductive electrodes in the display system often have certain distances from some conductive electrodes in the touch detection system, thus forming some specific capacitors
Data Source
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AI summary
A touch control chip, a touch detection method, a touch detection system and an electronic device, and the touch chip includes: a synchronization module, a touch drive module, and a touch detection module. The synchronization module is electrically connected to a display drive chip, to enable touch driving performed by the touch drive module to have an association relationship with a display control signal of the display drive chip; the synchronization module is electrically connected to the touch drive module, to enable the touch drive module to drive a touch sensor under control of the display control signal; and the touch detection module is electrically connected to the touch sensor, to detect an output signal of the touch sensor to determine a touch position. The touch detection system cancels or reduces interference from a display system, thereby improving the signal-to-noise ratio of the touch detection system and further improving the sensitivity of touch detection.