Dual Capacitive Touch Confirmation for False Touch Reduction
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Solution Overview
Problem
Capacitive touch-sensitive screens often experience 'false touches' due to incidental contact with objects that increase capacitance similarly to a human finger, and traditional force sensing systems are costly and complex.
Innovation Solution
A dual capacitive touch confirmation system that combines a primary capacitive touch sensing array with a secondary sensor array, using capacitance changes to differentiate between potential and confirmed touches, thereby reducing false activations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single capacitive touch sensing array is used, then the device is simple and low-cost, but false touches occur due to incidental contact with objects that provide similar capacitance increases
Solution Approach 1:
The touch detection system is segmented into two separate capacitive sensor arrays: a first array for initial touch detection and a second array for confirmation. This segmentation allows the system to distinguish between valid touches and false activations by requiring correlation between the two arrays, thereby improving reliability without excessive complexity.
Solution Approach 2:
A microcontroller acts as an intermediary between the two capacitive sensor arrays, processing capacitance changes from the first array and using them to modulate the second array. This intermediary processing enables the system to filter false touches by comparing capacitance changes across both arrays before confirming a touch event.
2Measurement precision
If traditional force sensing systems with force sensors and auxiliary circuitry are used, then force detection is achieved, but cost, circuit board area, and mechanical component complexity increase
Solution Approach 1:
The patent replaces traditional mechanical force sensors with a capacitive sensing system that uses electrical field interactions to detect touch and infer force. By substituting mechanical sensing components with capacitive sensor arrays and electronic processing, the system achieves force detection capability while reducing mechanical complexity and component count.
Solution Approach 2:
The system detects force by measuring changes in capacitance parameters rather than relying on mechanical force sensors. The capacitance values from the sensor arrays are processed to infer touch force, allowing force measurement through electrical parameter changes instead of mechanical sensing components.
3Reliability
If additional force sensing components are added to reduce false touches, then touch accuracy improves, but cost and system complexity increase
Solution Approach 1:
The second capacitive sensor array serves multiple functions: it acts as a confirmation sensor for touch validation, a force detection sensor for distinguishing touch intensity, and a false touch filter. This multi-functionality reduces the need for separate dedicated components, thereby improving reliability while controlling manufacturing cost.
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 solution provides a low-cost, low-complexity method for force sensing in capacitive touch screens, effectively reducing false touches by utilizing a secondary sensor to detect force-related capacitance changes.
Implementation Method 1
A first capacitive sensor is positioned relative to the substrate such that the first capacitive sensor can detect the substrate being touched by a finger
Implementation Method 2
A second capacitive sensor is positioned relative to the first capacitive sensor such that the second capacitive sensor can detect a change in capacitance between the first capacitive sensor and the second capacitive sensor due to the elastic deformation of the substrate
Implementation Method 3
A substrate configured to be touched by and elastically deformed or deflected by a finger of a human user
Data Source
AI summary
A touch-sensitive screen arrangement includes a substrate configured to be touched by and elastically deformed or deflected by a finger of a human user. A first capacitive sensor is positioned relative to the substrate such that the first capacitive sensor can detect the substrate being touched by the finger. The first capacitive sensor is elastically deformed by the finger of the human user touching the substrate. A second capacitive sensor is positioned relative to the first capacitive sensor such that the second capacitive sensor can detect a change in capacitance between the first capacitive sensor, which is grounded to reduce the variability associated with the user, and the second capacitive sensor due to the elastic deformation of the first capacitive sensor that results from the substrate being touched by the finger.