Electrovibration Feedback Circuit for Compact Touch Panel Interfaces

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Solution Overview

Problem

Touch-based slider devices lack relative position or magnitude feedback, making them unsuitable for compact user interfaces and requiring additional displays for feedback, which increases size and complexity.

Innovation Solution

Implementing an electrovibration feedback circuit that generates a vibratory feedback simulating friction on a touch-sensitive surface, providing tactile feedback corresponding to operational adjustments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If a display is mounted remote from the slider to provide feedback, then feedback information is provided to the user, but the size of the user interface increases

Engineering Contradiction:
Improvefeedback informationVSAvoiduser interface size
Core Design Contradiction:
Loss of informationVSArea of stationary object

Solution Approach 1:

The patent combines the display function and feedback mechanism directly into the touch-sensitive surface itself. The electrovibration feedback circuit is integrated beneath the touch-sensitive external surface, allowing feedback to be generated at the exact location where the user interacts, eliminating the need for separate remote displays while maintaining feedback functionality.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent introduces electrovibration as an intermediary mechanism that transfers feedback information directly to the user's finger through the touch-sensitive surface. By simulating friction and providing tactile feedback at the point of contact, the system mediates between the user's touch input and the operational state, eliminating the need for visual displays.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Loss of information

If multiple separate components are used for touch input and feedback display, then feedback functionality is achieved, but device complexity increases

Engineering Contradiction:
Improvefeedback functionalityVSAvoidnumber of components
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

The patent merges the touch sensor array and electrovibration feedback circuit into a single integrated assembly. The control circuit receives touch inputs from the touch-sensitive circuit and simultaneously controls the electrovibration feedback circuit, which is coupled to the same external surface, creating a unified input-feedback system rather than separate components.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The touch-sensitive external surface serves multiple functions: it acts as both the input interface for detecting user touches and the output interface for providing electrovibration feedback. This multi-functionality eliminates the need for separate display components, reducing overall device complexity while maintaining full feedback capability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Ease of operation

If electrovibration feedback is used to simulate friction, then tactile feedback is provided at the touch surface, but energy consumption increases

Engineering Contradiction:
Improvetactile feedbackVSAvoidenergy consumption
Core Design Contradiction:
Ease of operationVSUse of energy by moving object

Solution Approach 1:

The electrovibration feedback circuit operates by applying periodic electrostatic forces to simulate friction. The system activates electrovibration only during touch interactions rather than continuously, using pulsed or periodic electrostatic fields to create the tactile feedback effect, thereby reducing overall energy consumption compared to continuous operation.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system dynamically adjusts the electrostatic force parameters based on the detected touch position and operational context. By varying the voltage amplitude and frequency of the electrovibration feedback according to the user's interaction state, the system provides effective tactile feedback while minimizing energy consumption by avoiding maximum power output at all times.

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

Enhances user interaction by offering precise and intuitive control through tactile feedback, allowing compact designs without additional displays.

Implementation Method 1

The electrovibration feedback circuit is configured to generate said vibratory feedback via an electrostatic force that simulates friction between said user's finger and the external surface

Methodology Applied
Scientific EffectElectrostatic force: Electrostatics

Data Source

PatentEP3440890B1Appliance with electrovibration user feedback in a touch panel interface
Publication Date: 2025.07.16 ELECTROLUX HOME PRODUCTS INC
  • EP3440890B1 patent drawingFigure 1
  • EP3440890B1 patent drawingFigure 2
  • EP3440890B1 patent drawingFigure 3

AI summary

A cooking appliance includes a plurality of electrically controlled heating elements operable to elevate a temperature of food items. A user interface includes a touch-sensitive circuit that is operativeiy-connected to an external surface of the cooking appliance for altering operational settings of the electrically controlled heating elements. An electrovibrafion feedback circuit is coupled to the external surface that generates a vibratory feedback that is sensible by the user's finger at the external surface in response to adjustments of the operational settings. The electrovibration feedback circuit creates an electrostatic force on the user's finger that simulates friction between the user's finger and the external surface.