Flexible Touch Screen Physical Feedback Using Electromagnetic Actuation

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Solution Overview

Problem

The existing physical feedback systems for flexible touch screens using electrified liquid media suffer from long response times, limiting the speed of physical deformation and user interaction.

Innovation Solution

A physical feedback system utilizing an armature part and a coil part, where energizing the coil part under electromagnetic action rapidly changes the relative distance between the armature and coil parts, enabling quick deformation of the flexible touch screen, thus shortening response times.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an electrified liquid medium is used to implement physical feedback, then the flexible touch screen can provide physical deformation feedback to users, but the response time for generating physical deformation is relatively long

Engineering Contradiction:
Improvephysical feedback capabilityVSAvoidresponse time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent changes the physical state and properties of the materials involved. Specifically, it uses a magnetorheological fluid that can rapidly change its viscosity and deformation characteristics in response to magnetic field changes, enabling fast response times while maintaining physical feedback capability. The flexible layer and rigid layer materials are also selected to optimize deformation speed and recovery.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces the traditional electrified liquid medium (which relies on electrostatic or electrowetting effects) with a magnetorheological fluid system driven by magnetic fields. This substitution enables faster response times because magnetic field generation and modulation can occur more rapidly than the electrical charging and discharging processes in liquid-based systems.

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

2Loss of information

If the display contents of the screen are changed, then the information display is updated, but a relatively long time is needed to complete the refreshing process of the physical deformation

Engineering Contradiction:
Improvedisplay content updateVSAvoidrefreshing time
Core Design Contradiction:
Loss of informationVSLoss of time

Solution Approach 1:

The patent implements preliminary action by pre-positioning the magnetorheological fluid and magnetic components in readiness. When display content needs to be updated, the system can rapidly switch between pre-configured magnetic field patterns without requiring substantial material repositioning or system reconfiguration, thereby reducing the refreshing time for physical deformation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent employs dynamic control of the magnetorheological fluid through rapidly switchable magnetic fields. The system can dynamically adjust the deformation patterns of the flexible layer to match changing display content in real-time, enabling synchronized updates of visual and physical feedback without long refreshing delays.

Inventive Principle:
Principle #15Dynamics

3Stability of the object's composition

If a rigid touch display screen is used, then the screen structure is stable and durable, but the user can only perform operations on a flat surface lacking physical feedback

Engineering Contradiction:
Improvescreen structure stabilityVSAvoidphysical feedback
Core Design Contradiction:
Stability of the object's compositionVSEase of operation

Solution Approach 1:

The patent segments the touch display structure into distinct functional layers: a stable rigid layer providing structural support, a flexible layer capable of deformation, and a magnetorheological fluid layer enabling controlled physical feedback. This segmentation allows each layer to optimize its specific function while working together as an integrated system.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a flexible layer with magnetorheological fluid that can dynamically change its physical form between flat and deformed states. This flexible component is sandwiched between rigid layers, allowing it to provide tactile feedback while the rigid layers maintain overall structural stability and protection.

Inventive Principle:
Principle #30Flexible shells and thin films

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

This approach significantly reduces response times for physical feedback on flexible touch screens, enhancing user interaction speed and accuracy by allowing rapid formation of protrusions or depressions, improving the overall user experience.

Implementation Method 1

When the coil part is energized, the relative distance between the armature part and the coil part is changed under an electromagnetic action

Methodology Applied
Scientific EffectElectromagnetic action: Electromagnetic Induction

Data Source

PatentEP2966542B1Physical feedback system, control method and device, display assembly and electronic device
Publication Date: 2021.10.06 XIAOMI INC
  • EP2966542B1 patent drawingFigure 1~2C
  • EP2966542B1 patent drawingFigure 3A~3B
  • EP2966542B1 patent drawingFigure 3C~3E

AI summary

Disclosed are a physical feedback system, a control method and device, a display assembly and an electronic device, which belong to the field of display screens. The system comprises: at least one physical feedback unit located below a flexible touchscreen; the physical feedback unit comprises an armature part and a coil part, wherein at least one of the armature part and the coil part is in an active state, and the initial relative distance between the armature part and the coil part is a predetermined value; when the coil part is energized, the relative distance between the armature part and the coil part is changed under the action of electromagnetism, and the changed relative distance is greater than or smaller than the predetermined value, so that a bulge or a depression is formed in the corresponding location of the flexible touchscreen. This disclosure solves the problem that the response time is too long when using a charged liquid medium for implementation; and achieves the effects of being able to rapidly physically deform the flexible touchscreen by only energizing the coil part, and of shortening the response time.