Touch Panel Bending Wave Steering for Crosstalk Reduction

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Solution Overview

Problem

Existing touch-sensitive devices struggle to provide effective tactile feedback when multiple areas of a touch screen are simultaneously contacted, leading to interference and reduced signal clarity.

Innovation Solution

A touch-sensitive device with a panel capable of supporting bending waves, featuring multiple sensing areas and vibration exciters that apply bending waves to maximize tactile feedback at the touched area while minimizing it at other areas, using signal processing to steer and optimize the vibration amplitude and reduce crosstalk.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple vibration exciters are used to provide tactile feedback at multiple sensing areas, then the tactile feedback coverage is improved, but the crosstalk and interference between areas increases

Engineering Contradiction:
Improvetactile feedback coverageVSAvoidcrosstalk and interference
Core Design Contradiction:
Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The patent applies local quality by making each sensing area have distinct vibration characteristics through signal processing. The system steers bending waves to maximize amplitude at the touched sensing area while minimizing it at other areas, ensuring that each location receives primarily the haptics signal for that specific location. This creates spatially differentiated vibration patterns that provide clear, location-specific feedback without mutual interference.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent employs parameter changes by dynamically adjusting the amplitude and phase parameters of bending waves applied by multiple vibration exciters. The signal processing means modifies these parameters in real-time based on which sensing area is touched, thereby maximizing the vibration amplitude at the target area while reducing it at other areas. This parameter control enables simultaneous multi-region haptics with high signal-to-noise ratio.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If vibration amplitude is maximized at the touched area, then the tactile feedback clarity is improved, but the vibration at other areas increases causing interference

Engineering Contradiction:
Improvetactile feedback clarityVSAvoidunwanted vibrations
Core Design Contradiction:
Measurement precisionVSObject-generated harmful factors

Solution Approach 1:

The system ensures that each sensing area receives primarily the haptics signal for that location by steering bending waves to create localized vibration patterns. The signal processing means controls the vibration exciters to maximize amplitude at the touched area while minimizing amplitude at other sensing areas, thereby providing clear tactile feedback without unwanted vibrations at other locations.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent converts the potentially harmful effect of wave interference into a beneficial phenomenon by using constructive and destructive interference of bending waves. The signal processing means exploits wave interference patterns to create areas of strong vibration (constructive interference) at the touched location and areas of weak vibration (destructive interference) at other locations, thereby achieving spatially selective tactile feedback.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Productivity

If simultaneous haptic feedback is provided at multiple locations, then the user interaction capability is improved, but the signal-to-noise ratio decreases

Engineering Contradiction:
Improveuser interaction capabilityVSAvoidsignal-to-noise ratio
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The signal processing means dynamically changes the amplitude and phase parameters of bending waves from multiple vibration exciters to maximize the signal-to-noise ratio at each touched sensing area. By adjusting these parameters in real-time, the system ensures that each location receives a strong, clear haptic signal while other areas experience minimal vibration, thereby maintaining high signal-to-noise ratio even during simultaneous multi-region haptics.

Inventive Principle:
Principle #35Parameter changes

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 solution ensures clear, simultaneous haptic feedback at multiple spatially separate locations, improving the signal-to-noise ratio and reducing unwanted vibrations, thereby enhancing the user experience by providing precise tactile feedback without acoustic interference.

Implementation Method 1

a panel capable of supporting bending waves, a user-accessible touch sensitive screen on or forming part of a face of the panel, the touch sensitive screen having a plurality of different sensing areas, a plurality of vibration exciters coupled to the panel to apply bending waves to the panel to provide tactile feedback at the plurality of sensing areas

Methodology Applied
Scientific EffectBending waves: Vibration

Implementation Method 2

signal processing means arranged to apply signals to the vibration exciters so as to steer bending waves applied to the panel by the plurality of vibration exciters whereby the amplitude of the applied bending waves is maximised at the sensing area touched by the user and reduced or minimised at each other sensing area

Methodology Applied
Scientific EffectWave interference: Interference

Data Source

PatentEP2684111B1Touch sensitive device
Publication Date: 2019.11.20 GOOGLE LLC
  • EP2684111B1 patent drawingFigure 1a
  • EP2684111B1 patent drawingFigure 1b
  • EP2684111B1 patent drawingFigure 2a

AI summary

A touch sensitive device comprising a panel capable of supporting bending waves, a user-accessible touch sensitive screen on or forming part of a face of the panel, the touch sensitive screen having a plurality of different sensing areas, a plurality of vibration exciters coupled to the panel to apply bending waves to the panel to provide tactile feedback at the plurality of sensing areas in response to the user touching a sensing area, and signal processing means arranged to apply signals to the vibration exciters so as to steer bending waves applied to the panel by the plurality of vibration exciters whereby the amplitude of the applied bending waves is maximised at the sensing area touched by the user and reduced or minimised at each other sensing area.