Touch Screen Full-Screen Drive Detection for Water False Touches
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Solution Overview
Problem
Conventional capacitive touch screens face misjudgments due to water stains or conductive substances that cross multiple conductive strips, leading to false detection of external touch or approach.
Innovation Solution
Implementing a full screen driven detection method where a driving signal is simultaneously provided to all conductive strips, allowing for one-dimensional sensing information to be generated and determining external conductive objects coupled to ground, with a subsequent 2D mutual capacitive detection updating reference values when no external object is detected.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional mutual capacitive detection is used, then touch position can be detected, but water stains or conductive substances cause misjudgment by mimicking touch events
Solution Approach 1:
The system dynamically switches between two detection modes: full-screen driven detection for rapid water stain identification, and traditional mutual capacitive detection for precise touch positioning. This dynamic adaptation allows the system to maintain high reliability in both wet and dry conditions while preserving measurement precision.
Solution Approach 2:
The controller periodically performs full-screen driven detection to scan for water stains or conductive substances. When no external objects are detected during these periodic scans, the system transitions to traditional mutual capacitive detection for normal touch operation, creating a rhythmic detection pattern that ensures reliability without compromising touch responsiveness.
2Measurement precision
If traditional mutual capacitive detection is used, then touch position can be detected, but detection time and power consumption increase due to sequential scanning
Solution Approach 1:
The detection process is segmented into two distinct phases: full-screen driven detection that simultaneously drives all conductive strips for rapid water stain scanning, and traditional mutual capacitive detection that sequentially scans for precise touch positioning. This segmentation allows the system to optimize for speed during water stain detection and for precision during normal touch operation.
Solution Approach 2:
The system performs partial full-screen driven detection by simultaneously driving all conductive strips only when water stain detection is needed, rather than continuously. This partial application of the full-screen method reduces overall power consumption and time loss while maintaining the ability to quickly identify water stains when present.
3Reliability
If full-screen driven detection is used, then water stain detection accuracy improves, but power consumption increases due to simultaneous driving of all conductive strips
Solution Approach 1:
The full-screen driven detection is performed periodically rather than continuously, allowing the system to maintain high water stain detection accuracy while reducing average power consumption. The controller alternates between periodic full-screen scans and lower-power traditional detection modes, creating an energy-efficient detection rhythm.
Solution Approach 2:
The system applies full-screen driven detection only partially - specifically when water stain detection is required - rather than continuously. This selective application maintains high detection accuracy when needed while minimizing power consumption during normal operation, achieving an optimal balance between reliability and energy efficiency.
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 approach effectively differentiates between real and unreal touches, including those caused by water stains, and reduces power consumption, making it suitable for power-saving modes.
Implementation Method 1
capacitive coupling signals at the intersections between the first conductive strip provided with the driving signal and all the second conductive strips
Implementation Method 2
a driving signal is sequentially provided to each first conductive strip, and corresponding to each first conductive strip provided with the driving signal, signals from all of the second conductive strips are detected
Data Source
AI summary
The invention discloses a full screen driven detection. A driving signal is simultaneously provided to all first conductive strips arranged in parallel in a first direction in a touch screen, and mutual capacitive signals are detected from all second conductive strips arranged in parallel in a second direction. The mutual capacitive signals can be used for determining whether an external conductive object coupled to the ground is touching or approaching the touch screen or not even if water or other conductive object not coupled to ground is on the touch screen. Thus, the baseline of the mutual capacitive signals can be updated if the touch screen is not touched or approached by any external conductive object coupled to ground over a predetermined period of time.