Capacitive Touch Panel With Electrorheological Fluid Tactile Feedback

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Solution Overview

Problem

Existing touch panels lack the tactile feedback similar to mechanical keypads, which is essential for providing a satisfying input experience.

Innovation Solution

A capacitive-type touch panel utilizing electrorheological fluid with a driving device that applies a combined signal of driving and sensing voltages to electrode pairs, increasing the viscosity of the fluid to simulate a clicking sensation upon input detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a vibration motor is installed below the touch panel to provide tactile feedback, then the sense of input is improved, but the vibration is whole-panel and differs from mechanical keypad sensation

Engineering Contradiction:
Improvesense of inputVSAvoidvibration mechanism
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The touch panel is divided into multiple independently controllable electrode pairs that can be activated selectively. Instead of using a single vibration motor that vibrates the entire panel, the patent applies electric fields to specific electrode pairs to create localized viscous changes in the electrorheological fluid, providing segmented and precise tactile feedback corresponding to different input regions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent replaces the mechanical vibration motor system with an electrorheological fluid-based system controlled by electric fields. The electrorheological fluid's viscosity changes in response to applied electric fields, creating tactile resistance and feedback without mechanical moving parts, thus substituting a mechanical vibration system with an electro-fluidic system.

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

2Ease of operation

If electrorheological fluid is used to provide tactile feedback, then the viscosity control is improved, but the device complexity increases

Engineering Contradiction:
Improvetactile feedbackVSAvoidfluid control system
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent utilizes the property of electrorheological fluid that its viscosity can be changed by altering the electric field parameters. By applying different voltages to electrode pairs, the viscosity of the fluid in specific regions is dynamically adjusted, providing tactile feedback. This parameter-based control allows precise viscosity modulation without complex mechanical fluid handling systems.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The electrorheological fluid acts as an intermediary between the electric field and the tactile feedback mechanism. The fluid mediates the conversion of electrical energy into mechanical resistance and tactile sensation, allowing the system to provide tactile feedback without direct mechanical contact or complex actuation mechanisms.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of operation

If the whole touch panel is vibrated by a vibration motor, then the input detection is enhanced, but the localization precision is reduced

Engineering Contradiction:
Improveinput detectionVSAvoidinput location
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The touch panel is segmented into multiple electrode pairs that can be independently activated. When a user touches the panel, the system can selectively activate electrode pairs in the vicinity of the touch location, providing localized tactile feedback and enhancing input location precision. This segmented approach allows the system to distinguish between different input locations based on which electrode pairs are activated.

Inventive Principle:
Principle #1Segmentation

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 touch panel effectively replicates the tactile feedback of a mechanical keypad by varying the viscosity of the electrorheological fluid, providing a satisfying input experience through controlled repulsive forces and capacitance changes.

Implementation Method 1

an electrorheological fluid interposed between the first and second substrates; a driving device configured to apply, to the one or more of the first electrode lines, a combined signal obtained by combining a driving voltage for varying the viscosity of the electrorheological fluid with a sensing voltage

Methodology Applied
Scientific EffectElectrorheological effect: Electrorheological Effect

Implementation Method 2

a driving device configured to apply, to the one or more of the first electrode lines, a combined signal obtained by combining a driving voltage for varying the viscosity of the electrorheological fluid with a sensing voltage

Methodology Applied
Scientific EffectViscosity variation:

Implementation Method 3

a sensing device configured to be connected to the second electrode lines and detect an input to the touch panel in response to the sensing voltage being applied to the one or more of the first electrode lines

Methodology Applied
Scientific EffectCapacitance: Capacitance

Data Source

PatentEP2515211B1Touch panel and driving device for the same
Publication Date: 2017.06.21 SAMSUNG ELECTRONICS CO LTD
  • EP2515211B1 patent drawingFigure 1
  • EP2515211B1 patent drawingFigure 2
  • EP2515211B1 patent drawingFigure 3

AI summary

A driving device and a touch panel are provided. The driving device includes a first switcher and a second switcher. The first switcher is coupled to a first electrode of a capacitance node of the touch panel and is configured to selectively apply, to the first electrode, a driving voltage for generating an electric potential difference in the capacitance node. The second switcher is coupled to the first electrode and configured to selectively apply, to the first electrode, a sensing voltage for sensing a variation in the capacitance of the at least one capacitance node.