Touch Location Determination Using Historical Data

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Solution Overview

Problem

Existing touch-sensitive displays in portable electronic devices face challenges in accurately determining the location of touches when multiple touches overlap in time, particularly when one touch is discontinued, leading to incorrect pairing of coordinate values and ghost touches.

Innovation Solution

A method is implemented where first touch data is used to identify the location of touches, and if it is not accurate, previous touch data is obtained to determine the location, ensuring accurate identification of touch positions by utilizing a processor and touch-sensitive display system.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple touches are detected simultaneously on the touch-sensitive display, then the device can support multi-touch operations, but coordinate pairing errors and ghost touches occur when touches overlap in time

Engineering Contradiction:
Improvemulti-touch capabilityVSAvoidtouch location accuracy
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The system performs preliminary actions by storing historical touch data and coordinate information in advance. When a touch is detected, the system retrieves previously stored touch data to compare and verify the current touch location, preventing coordinate pairing errors before they occur

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system implements feedback by continuously monitoring touch data accuracy and using previously detected touch locations to validate current touch measurements. When coordinate pairing errors are detected, the system uses feedback from historical data to correct the erroneous readings

Inventive Principle:
Principle #23Feedback

2Speed

If touch data is processed in real-time without verification, then processing speed is maintained, but incorrect touch locations are identified due to coordinate mismatches

Engineering Contradiction:
Improvetouch processing speedVSAvoidtouch data accuracy
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The system performs preliminary verification by comparing current touch data against previously stored touch data before finalizing the touch location determination. This preliminary check prevents incorrect locations from being processed further

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system applies partial verification by selectively retrieving and comparing only relevant portions of historical touch data with current touch data. This approach provides sufficient verification to ensure accuracy without excessively slowing down the processing speed

Inventive Principle:
Principle #16Partial or excessive action

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 resolves the issue of ghost touches by using previous touch data to correct coordinate mismatches, ensuring accurate touch location determination and preventing incorrect function performance.

Implementation Method 1

projective capacitive touch panel

Methodology Applied
Scientific EffectCapacitance: Capacitance

Data Source

PatentEP2407866B1Portable electronic device and method of determining a location of a touch
Publication Date: 2018.11.28 BLACKBERRY LTD
  • EP2407866B1 patent drawingFigure 1
  • EP2407866B1 patent drawingFigure 2
  • EP2407866B1 patent drawingFigure 3

AI summary

A method includes determining when a touch of a plurality of touches overlapping in time on a touch-sensitive display, is discontinued, utilizing first touch data prior to the determining to identify a location of the touch, and when the first touch data is not established to be accurate, obtaining second touch data prior to the first touch data to identify the location of the touch.