Touch Screen Haptic Calibration via Vibration Reciprocity

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Solution Overview

Problem

Existing touch-sensitive devices require laborious calculations to generate desired haptic sensations across multiple regions on the screen, making them inefficient for complex systems that provide tactile feedback simultaneously at multiple locations.

Innovation Solution

A self-calibrating touch-sensitive device that uses a processor and a plurality of transducers to detect and process vibrations, allowing the device to generate a desired haptic sensation without calculating transfer functions, leveraging reciprocity principles and adaptive filtering techniques to determine output signals for each transducer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If transfer functions are calculated to generate desired haptic sensations at multiple screen regions, then haptic feedback precision is improved, but calculation time and system complexity increase

Engineering Contradiction:
Improvehaptic feedback precisionVSAvoidcalculation time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system performs self-calibration by automatically measuring the screen's vibration response to impulsive inputs and using this measured data to compute the inverse transfer functions. This eliminates the need for manual calculation of complex transfer functions while achieving precise haptic feedback control.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system measures the actual vibration response of the screen at multiple locations and uses this feedback information to compute the inverse transfer functions. This closed-loop approach allows the system to adapt to the actual physical characteristics of the screen, achieving precise haptic feedback without requiring complex pre-calculated transfer functions.

Inventive Principle:
Principle #23Feedback

2Measurement precision

If transfer functions are calculated for multi-region haptics, then haptic feedback accuracy is improved, but device complexity increases

Engineering Contradiction:
Improvehaptic feedback accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system automatically performs calibration by measuring vibration responses and computing inverse transfer functions without requiring manual intervention or complex pre-computed models. This self-calibrating approach simplifies the system while maintaining high accuracy for multi-region haptic feedback.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system replaces complex mathematical modeling and manual calculation of transfer functions with a direct measurement-based approach. By measuring the actual vibration responses and using these measurements to compute the inverse transfer functions, the system eliminates the need for complex theoretical models while achieving the same or better accuracy.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If manual calculations are used to generate haptic sensations, then control precision is improved, but ease of operation decreases

Engineering Contradiction:
Improvecontrol precisionVSAvoidease of calibration
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The system performs self-calibration by automatically measuring the screen's vibration response to impulsive inputs and using this measured data to compute the inverse transfer functions. This eliminates the need for manual calculation of complex transfer functions while achieving precise haptic feedback control.

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

The device can autonomously calibrate to produce precise haptic feedback, reducing the need for manual calculations and improving efficiency in generating complex haptic sensations across multiple screen regions.

Implementation Method 1

a plurality of transducers mounted to the screen... detecting vibration in the screen using the plurality of transducers

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

when the transducers are driven by the output signals the screen is excited into generation of a desired haptics sensation

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentEP2417511B1Touch sensitive device
Publication Date: 2016.11.09 NVF TECH
  • EP2417511B1 patent drawingFigure 1~2a
  • EP2417511B1 patent drawingFigure 2b~2c
  • EP2417511B1 patent drawingFigure 3a~3c

AI summary

A method of calibrating a touch sensitive device comprising a touch-sensitive screen; a plurality of transducers mounted to the screen and a processor, the method comprising inputting a signal into the screen at a test position on the screen whereby the screen is excited into vibration; detecting vibration in the screen using the plurality of transducers; and processing, in the processor of the touch-sensitive device, the detected vibration to generate an output signal for each of the plurality of transducers whereby when the transducers are driven by the output signals the screen is excited to generate a desired haptics sensation at the test position.