Touch Sensor Signal Integration for Display Noise Reduction
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Solution Overview
Problem
Current touch sensors face challenges in accurately detecting the presence and position of objects within touch-sensitive areas, particularly in reducing noise and flicker when integrated with display systems, which can affect the reliability of touch measurements.
Innovation Solution
A touch sensor system that includes a controller performing specific integration and phase shift operations synchronized with display synchronization signals to reduce noise and flicker, using a pattern of positive and negative integrations with gaps to invert the phase of cross-talk between display source data and drive signals, thereby enhancing touch measurement accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If touch sensor integrates with display system, then display functionality is enhanced, but noise and flicker increase affecting touch measurement accuracy
Solution Approach 1:
The patent implements periodic integration operations synchronized with display refresh cycles. The controller performs integration at specific phases (rising and falling edges) of display synchronization signals, creating a periodic sampling pattern that eliminates noise and flicker while maintaining touch detection accuracy throughout the display cycle.
Solution Approach 2:
The system uses feedback from display synchronization signals to control the timing of integration operations. The controller monitors display sync signals and adjusts integration timing accordingly, creating a closed-loop system that synchronizes touch sensing with display operations to eliminate interference and improve measurement precision.
2Measurement precision
If integration operations are performed continuously, then touch measurement coverage is maximized, but noise and cross-talk from display signals increase
Solution Approach 1:
Instead of continuous integration, the system performs periodic integration at specific phases of display synchronization signals. This selective periodic sampling captures touch information at optimal moments when display-related noise is minimal, while the periodic nature ensures complete coverage across all display cycles.
Solution Approach 2:
The system performs preliminary integration operations at predetermined phases of display sync signals before potential interference occurs. By anticipating and preparing measurements at optimal timing points, the system avoids capturing noise and cross-talk during problematic periods while maintaining comprehensive measurement coverage.
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 solution effectively reduces display noise and flicker while maintaining touch measurement performance, improving the accuracy and reliability of object detection within touch-sensitive areas.
Implementation Method 1
a change in capacitance may occur within the touch screen at a position of the touch sensor of the touch screen that corresponds to the position of the object within the touch sensitive area of the touch sensor
Data Source
AI summary
In certain embodiments, a method includes performing a first positive integration by sensing a first rising edge of a charging signal of a touch sensor during a first synchronization period, performing a first negative integration by sensing a first falling edge of the charging signal during a second synchronization period, and performing a first phase shift by skipping integration during a third synchronization period. The method further includes performing a second positive integration by sensing a second rising edge of the charging signal during a fourth synchronization period, performing a second negative integration by sensing a second falling edge of the charging signal during a fifth synchronization period, and performing a second phase shift by skipping integration during a sixth synchronization period. The first integrations are associated with a first sample measurement and the second integrations are associated with a second sample measurement.