Benchmark Updating for Touch Detection Eliminating Large-Area Interference

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Solution Overview

Problem

Mutual capacitance touch detection systems in handheld devices often misdetect user inputs due to large-area interference, leading to persistent key-pressing operations and inability to respond to normal user operations, as the difference data characteristics between fingers and large-area interference are similar, making it difficult to distinguish between normal touches and misoperation points.

Innovation Solution

A benchmark updating method and system that calculates a reference consistency value for touch detection nodes, samples data to determine current consistency, and updates the benchmark if the current consistency is less than the reference consistency by a constant value, distinguishing between real user operations and misoperation points caused by large-area interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a mutual capacitance touch detection scheme is used, then touch detection capability is provided, but misdetection occurs when large-area interference (such as palm pressing) is present during initialization or operation

Engineering Contradiction:
Improvetouch detection accuracyVSAvoidlarge-area interference
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The system performs preliminary sampling of touch detection nodes to establish baseline benchmark values before normal touch detection begins. By pre-characterizing the touch screen's electrical properties under known conditions (no touch), the system creates a reference state that enables later detection of actual touch events while filtering out large-area interference patterns.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system continuously monitors touch detection node data, compares current readings against stored benchmark values, and uses this feedback to distinguish between normal finger touches and large-area interference. The comparison mechanism provides real-time feedback that enables the system to adaptively reject interference while maintaining accurate touch detection.

Inventive Principle:
Principle #23Feedback

2Measurement precision

If benchmark values are established during initialization, then touch detection baseline is set, but persistent key-pressing misdetection occurs after large-area interference is removed

Engineering Contradiction:
Improvetouch position detection accuracyVSAvoidoperation response accuracy
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The benchmark values are not fixed but dynamically updated based on continuous sampling and comparison. The system adapts the baseline characteristics over time, allowing it to recover from large-area interference events and maintain accurate touch detection. This dynamic adjustment prevents persistent misdetection by continuously refining the reference state.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the electrical parameters (capacitance values) of touch detection nodes by updating benchmark values when interference is detected and removed. By modifying these parameters based on current conditions rather than relying on initial initialization values, the system maintains measurement precision while avoiding persistent misdetection.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If difference data characteristics are used for touch detection, then multi-finger touch capability is achieved, but inability to distinguish between normal touches and misoperation points occurs

Engineering Contradiction:
Improvemulti-touch detection capabilityVSAvoidtouch type discrimination accuracy
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The system adds a new dimension of analysis by comparing touch detection data against temporal baselines (benchmark values established at different times). Instead of relying solely on spatial difference data between nodes, the temporal comparison dimension enables discrimination between normal touches and misoperation points while preserving multi-finger touch capability.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 method effectively reduces misdetection phenomena by accurately differentiating between real user inputs and misoperation points, ensuring normal user operations are responsive and preventing device crashes due to incorrect benchmark values.

Implementation Method 1

When a mutual capacitance touch detection scheme is applied to a handheld terminal device

Methodology Applied
Scientific EffectMutual capacitance: Capacitance

Data Source

PatentUS9946623B2Benchmark updating method and system for touch detection terminal capable of eliminating large-area interference
Publication Date: 2018.04.17 SHENZHEN GOODIX TECH CO LTD
  • US9946623B2 patent drawing
  • US9946623B2 patent drawing
  • US9946623B2 patent drawing

AI summary

The present invention is applicable to the technical field of touch control, and provides a benchmark updating method for a touch detection terminal under large-area interference. The present invention can reduce the phenomenon of misdetection by performing consistency analysis on an original sampled value.