Touch Screen Floating State Determination and Compensation

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Solution Overview

Problem

Touch screen devices face challenges in accurately identifying touch positions and number of fingers in floating environments, leading to coordinate jitter and point vanishing issues, which existing methods fail to address by determining the floating state or performing floating compensation.

Innovation Solution

The method involves performing two times of self-capacitance interlaced driving in both driving and sensing directions, calculating self-capacitance differences, and determining a floating level for each channel to enable floating state determination and compensation, allowing normal operation of capacitive screens even in floating conditions, especially when multiple fingers are used.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If hardware design increases cover thickness to increase channel layer height, then touch sensitivity is improved, but device thickness increases

Engineering Contradiction:

Improvetouch sensitivityVSAvoiddevice thickness

Core Design Contradiction:

Measurement precisionVSLength of moving object

Solution Approach 1:

The patent changes the electrical parameters (driving voltage, sensing threshold) and structural parameters (channel layer conductivity, electrode arrangement) to optimize touch sensitivity without increasing physical thickness. The method uses interlaced driving patterns and dynamic threshold adjustment to enhance measurement precision while maintaining compact device dimensions.

Inventive Principle:

Principle #35Parameter changes

2Speed

If software algorithms reduce touch threshold to optimize coordinate detection, then touch responsiveness is improved, but false detection increases

Engineering Contradiction:

Improvetouch responsivenessVSAvoiddetection accuracy

Core Design Contradiction:

SpeedVSReliability

Solution Approach 1:

The patent implements feedback mechanisms where the system continuously monitors touch events and adjusts detection thresholds dynamically. The algorithm analyzes coordinate patterns, finger count consistency, and pressure distribution to distinguish valid touches from false detections, maintaining high responsiveness while ensuring detection reliability through adaptive threshold adjustment.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system performs preliminary validation of touch events by checking multiple parameters (coordinate consistency, finger count stability, pressure distribution) before confirming a touch detection. This preliminary action filters out false detections while maintaining rapid response to genuine touches.

Inventive Principle:

Principle #10Preliminary action

3Device complexity

If floating compensation is not performed, then device complexity is reduced, but touch accuracy deteriorates in floating environment

Engineering Contradiction:

Improvesystem complexityVSAvoidtouch accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent implements self-service floating compensation where the system automatically detects floating conditions and applies compensation algorithms without requiring external intervention or complex additional hardware. The touch controller monitors its own performance metrics and adjusts parameters to maintain accuracy in floating environments.

Inventive Principle:

Principle #25Self-service

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 determines the floating state and compensates for it, ensuring accurate touch recognition and performance on capacitive screens, even under floating conditions with multiple fingers, by calculating interlaced differential values and using compensation factors to adjust for mutual capacitance differences.

Implementation Method 1

performing two times of self-capacitance interlaced driving on the touch screen in each of a driving direction and a sensing direction; calculating self-capacitance differences corresponding to the two times of self-capacitance interlaced driving

Methodology Applied

Scientific EffectCapacitance: Capacitance

Data Source

PatentUS10983632B2Floating state determination and floating compensation methods and apparatuses for touch screen

Publication Date: 2021.04.20 SHENZHEN GOODIX TECH CO LTD

AI summary

Disclosed are floating state determination and floating compensation methods and apparatuses for a touch screen. The floating state determination method includes: performing two times of self-capacitance interlaced driving on the touch screen in each of a driving direction and a sensing direction; calculating self-capacitance differences corresponding to the two times of self-capacitance interlaced driving in each of the driving direction and a sensing direction, and obtaining an interlaced differential value of each channel based on the self-capacitance differences; and calculating a self-capacitance differential value of each channel, and determining a floating level of the channel based on the result of calculation. The floating state determination method can determine a floating state of the touch screen, and then a floating compensation is performed based on the floating state, so that the capacitive screen can be operated normally under floating.