Touch Device Haptic Feedback via Dual-Peak Signal Modulation

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Solution Overview

Problem

Existing touch-sensitive devices lack effective simulation of keyboard switch haptic sensations, as they primarily provide tactile feedback for discrete touches without accurately replicating the dynamic response of a keyboard switch.

Innovation Solution

A method and device that generate a carrier wave signal modulated with a modulation envelope comprising two exponential functions with different decay rates, producing a closely spaced pair of peaks to simulate the haptic sensation of a keyboard switch by exciting the touch-sensitive surface with a force exciter, potentially combined with audio cues for enhanced feedback.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a simple single impulse is generated to provide tactile feedback, then the device complexity is reduced, but the haptic sensation fails to accurately simulate keyboard switch feedback

Engineering Contradiction:
Improvesignal generation complexityVSAvoidhaptic sensation accuracy
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The single impulse signal is segmented into a double impulse signal with two distinct peaks separated by a time interval. This segmentation creates a more complex signal structure that accurately simulates the characteristic haptic sensation of keyboard switch feedback, resolving the contradiction by accepting increased signal complexity to achieve reliable haptic simulation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The signal parameters are changed by introducing a double impulse structure with specific time intervals and amplitude ratios between the two peaks. This parameter modification transforms a simple tactile feedback signal into one that reliably simulates keyboard switch haptics, addressing the accuracy requirement while maintaining manageable complexity.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If a double impulse signal with complex modulation envelope is used to simulate keyboard switch haptics, then the haptic sensation accuracy is improved, but the device complexity increases

Engineering Contradiction:
Improvehaptic sensation accuracyVSAvoidsignal generation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

A modulation envelope function serves as an intermediary element that shapes the carrier signal into a double impulse waveform. This envelope function with two exponential terms acts as a mediator between the simple carrier signal and the complex double impulse output, enabling accurate haptic simulation through a structured approach that manages complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The signal employs periodic modulation with a carrier wave that is modulated by the envelope function to produce the double impulse structure. This periodic action at the signal level creates the characteristic two-peak waveform needed for keyboard switch haptic simulation, achieving accuracy through structured periodic modulation rather than complex hardware.

Inventive Principle:
Principle #19Periodic 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

The solution effectively simulates the haptic sensation of a keyboard switch by producing a pair of impulses with controlled timing and amplitude, improving user experience through more realistic tactile and auditory feedback.

Implementation Method 1

a force exciter or actuator coupled to the touch-sensitive surface... driving the exciter or actuator with the modulated carrier wave signal to excite the touch-sensitive surface

Methodology Applied
Scientific EffectElectromagnetic actuation: Electromagnetic Induction

Implementation Method 2

modulating the carrier wave signal with a modulation envelope so that the modulated carrier wave signal has a closely spaced pair of peaks... to excite the touch-sensitive surface to provide a closely spaced pair of impulses

Methodology Applied
Scientific EffectMechanical vibration: Vibration

Data Source

PatentEP2483760B1Touch sensitive device generating a haptic feedback that simulates a click feeling
Publication Date: 2019.02.13 NVF TECH
  • EP2483760B1 patent drawingFigure 1a~1b
  • EP2483760B1 patent drawingFigure 2a~2b
  • EP2483760B1 patent drawingFigure 3~5

AI summary

A method of generating a keyboard switch haptic sensation in a coupled system comprising a touch-sensitive surface and a force exciter or actuator coupled to the touch-sensitive surface, the method comprising generating a carrier wave signal at frequencies within the frequency bandwidth of the coupled system, modulating the carrier wave signal with a modulation envelope so that the modulated carrier wave signal has a closely spaced pair of peaks, and driving the exciter or actuator with the modulated carrier wave signal to excite the touch-sensitive surface to provide a closely spaced pair of impulses whereby the keyboard switch haptic sensation is simulated to a user touching the touch-sensitive surface.