Dynamic Touch Threshold Adjustment for False Positive Reduction
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Solution Overview
Problem
Touch-sensitive devices often incorrectly detect unintentional touches, such as water or body proximity, leading to unintended device behavior due to unclear grounding conditions, which affects user experience.
Innovation Solution
The system adjusts touch sensitivity by determining the grounding state of the device, setting a touch detection threshold based on whether the device is well-grounded or poorly-grounded, allowing for better differentiation between intended and unintended touches by varying the signal density threshold.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a low touch detection threshold is set to ensure sensitivity to intended touches, then touch sensitivity is improved, but false positives from water or unintended touches increase
Solution Approach 1:
The touch detection threshold is made dynamic rather than static. The system continuously monitors grounding conditions and adjusts the threshold accordingly - using a lower threshold when grounding is poor to maintain sensitivity, and raising the threshold when grounding is good to reduce false positives. This dynamic adjustment resolves the contradiction between sensitivity and false positive reduction.
Solution Approach 2:
The system changes the threshold parameter based on grounding conditions. By monitoring electrical grounding state and adjusting the detection threshold parameter in response, the system adapts to different operational contexts. This parameter change allows the same hardware to achieve both high sensitivity and low false positive rates at different times.
2Object-affected harmful factors
If a high touch detection threshold is set to reject water or unintended touches, then false positives are reduced, but sensitivity to intended touches decreases
Solution Approach 1:
The threshold is dynamically adjusted based on real-time grounding condition assessment. When the system detects poor grounding (e.g., device not properly connected to ground reference), it lowers the threshold to maintain sensitivity. When grounding is good, it raises the threshold to reject false positives. This dynamic behavior allows the system to achieve both goals contextually.
Solution Approach 2:
The system uses feedback from grounding condition monitoring to adjust the detection threshold. The grounding status information feeds back into the threshold selection logic, creating a closed-loop system that automatically adapts. This feedback mechanism ensures the threshold is optimized for current operational conditions without manual intervention.
3Device complexity
If the touch detection threshold is fixed to simplify system operation, then device complexity is reduced, but the ability to differentiate between intended and unintended touches deteriorates
Solution Approach 1:
The system performs self-adjustment based on its own grounding conditions without requiring external configuration or user intervention. The threshold selection is automated through internal grounding detection, making the system self-optimizing. This self-service approach maintains simplicity from the user perspective while achieving high reliability through automatic adaptation.
Solution Approach 2:
Rather than using a fixed static threshold, the system employs a dynamic threshold that automatically adapts to grounding conditions. This dynamic approach achieves high differentiation accuracy while keeping the system operationally simple, as the adjustment happens transparently in the background without user involvement.
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 enhances the accuracy of touch detection, reducing false positives and improving user experience by effectively rejecting unintentional touches when the device is in a well-grounded state while ensuring sensitivity to intended touches in poorly-grounded conditions.
Implementation Method 1
in capacitive-type touch sensing systems, fringing electrical fields used to detect touch can extend beyond the surface of the display
Implementation Method 2
fringing electrical fields used to detect touch can extend beyond the surface of the display
Data Source
AI summary
A touch sensitivity of a touch-sensitive surface can be adjusted based on a state of a device including the touch-sensitive surface. The state of the device can be a first state or a second state. In the first state, for example, the touch sensing system of the device can be programmed to recognize and process a wide range of touch signals including relatively weak touch signals, which may correspond to water, liquid or other unintentional touches. In the second state, for example, the touch detection threshold can be adjusted to better reject water or unintended touches. In some examples, a ratio of measurements captured using the different types of scans of a selected touch node can be used to determine the state of the device.