Rollable Display Coil Assembly for Even Screen Expansion

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Solution Overview

Problem

Conventional rollable electronic devices face issues with screen deformation and uneven expansion/contraction due to concentrated driving force, often requiring multiple motors and complex structures, leading to defects like the middle area of the display being lifted.

Innovation Solution

The device incorporates a flexible display, a support member, a shaft bracket, and a coil assembly, with a coil assembly generating driving force for screen expansion/contraction, eliminating the need for separate motors and ensuring even force distribution across the display.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If a motor with a rotation shaft is used to drive the display, then the screen can be expanded and contracted, but the driving force is concentrated at one end causing the middle area to be lifted and deformed

Engineering Contradiction:
Improveautomatic screen expansion and contractionVSAvoiddisplay flatness and deformation
Core Design Contradiction:
Extent of automationVSManufacturing precision

Solution Approach 1:

The single motor is divided into multiple motors distributed along the display length. Each motor independently drives a corresponding segment of the display, transforming the concentrated driving force into distributed driving force, thereby preventing the middle area from being lifted and deformed during screen expansion and contraction

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Multiple motors are positioned at different locations along the display to provide locally optimized driving force. This ensures that each region of the display receives appropriate driving force, maintaining uniform expansion and contraction while preventing localized deformation

Inventive Principle:
Principle #3Local quality

2Area of moving object

If the overall length of the display is increased to increase display area, then the display area increases, but the structure becomes more complex and harder to control

Engineering Contradiction:
Improvedisplay areaVSAvoidstructure complexity
Core Design Contradiction:
Area of moving objectVSDevice complexity

Solution Approach 1:

The long display is divided into multiple segments, each driven by a separate motor. This segmentation allows the long display to be controlled in manageable sections, reducing the complexity of controlling the entire structure while maintaining the increased display area

Inventive Principle:
Principle #1Segmentation

3Force

If multiple motors are used to drive both ends of the shaft, then the driving force is improved, but the structure becomes more complex

Engineering Contradiction:
Improvedriving forceVSAvoidmotor structure complexity
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

Instead of using multiple motors at the ends of a single shaft, the invention segments the display into multiple sections, each with its own motor positioned along the length. This distributes the driving force more effectively while avoiding the complexity of interlocking shaft mechanisms

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent replaces the mechanical interlocking shaft system with independently controlled motors positioned along the display. This substitution simplifies the mechanical structure by eliminating complex shaft connections while maintaining or improving the driving force distribution

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

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 configuration prevents display deformation by evenly distributing driving force, enhances the driving output, and increases the diameter of the electromagnet actuator for circular driving.

Implementation Method 1

The coil assembly may be coupled to one side of the shaft bracket and may be configured to generate a driving force for moving the support member in a first direction or in a second direction opposite to the first direction

Methodology Applied
Scientific EffectElectromagnetic interaction: Electromagnetic Propulsion

Data Source

PatentEP4235356B1Rollable electronic device and method for operating same
Publication Date: 2026.02.18 SAMSUNG ELECTRONICS CO LTD
  • EP4235356B1 patent drawingFigure 1
  • EP4235356B1 patent drawingFigure 2
  • EP4235356B1 patent drawingFigure 3

AI summary

An electronic device according to various embodiments disclosed herein may include a flexible display, a support member, a shaft bracket, a coil assembly, and a printed circuit board. The flexible display may include a first region disposed so as to be visible from the outside and a second region that extends from the first region and that is accommodated inside when in a slide-in state and disposed so as to be visible from the outside when in a slide-out state. The support member is disposed on the rear surface of the flexible display and can support the flexible display in the slide-in state and the slide-out state. The shaft bracket may be disposed under the support member. The coil assembly is coupled to one side of the shaft bracket and can generate a driving force for moving the support member in a first direction or a second direction opposite to the first direction. An electronic component for supplying a driving current to the coil assembly may be disposed on the printed circuit board.