Fiber-Reinforced Elastic Member for Foldable Display Flatness

Solution Overview

Problem

Flexible or foldable display devices experience deterioration in flatness and reliability due to repeated folding and unfolding, leading to cracks and wrinkles, which reduce their lifespan and performance.

Innovation Solution

An elastic member with a first region for folding and a second region for unfolding, featuring a first layer and a second layer with fibers inside the base material, enhancing tensile and yield strength to prevent plastic deformation and improve folding reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the elastic member is folded repeatedly, then the device can be carried easily and the image display region can be increased, but the flatness deteriorates and cracks occur in the folding region

Engineering Contradiction:

ImproveportabilityVSAvoidflatness

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The elastic member is divided into multiple layers with different materials and functions. The first layer (flexible substrate) provides flexibility for folding, while the second layer (rigidifying layer with fibers) maintains flatness and prevents cracks. This segmentation allows each layer to specialize in one function, resolving the contradiction between foldability and flatness maintenance.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent uses composite materials by combining a flexible substrate material (first layer) with a rigidifying layer containing fibers (second layer). This composite structure enables the elastic member to be both flexible enough to fold repeatedly and strong enough to prevent crack formation, thus resolving the contradiction between portability and reliability.

Inventive Principle:

Principle #40Composite materials

2Ease of operation

If the elastic member is folded repeatedly, then the device can be carried easily, but the lifespan is reduced due to stress concentration in the folding region

Engineering Contradiction:

ImproveportabilityVSAvoidlifespan

Core Design Contradiction:

Ease of operationVSDuration of action of stationary object

Solution Approach 1:

The elastic member is divided into multiple layers with different materials and functions. The first layer (flexible substrate) provides flexibility for folding, while the second layer (rigidifying layer with fibers) maintains flatness and prevents cracks. This segmentation allows each layer to specialize in one function, resolving the contradiction between foldability and flatness maintenance.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The second layer with fibers is incorporated beforehand to prevent stress concentration and crack formation in the folding region. This preventive measure cushions against the harmful effects of repeated folding before damage can occur, thereby extending the lifespan while maintaining portability.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Ease of operation

If the elastic member is folded repeatedly, then the device can be carried easily, but wrinkles visually recognized from the outside occur

Engineering Contradiction:

ImproveportabilityVSAvoidflatness

Core Design Contradiction:

Ease of operationVSShape

Solution Approach 1:

The elastic member is divided into multiple layers with different materials and functions. The first layer (flexible substrate) provides flexibility for folding, while the second layer (rigidifying layer with fibers) maintains flatness and prevents cracks. This segmentation allows each layer to specialize in one function, resolving the contradiction between foldability and flatness maintenance.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent uses a flexible substrate (thin film) that can be folded, combined with a rigidifying layer that prevents excessive deformation. This combination allows the structure to be flexible enough for portability while maintaining sufficient flatness to prevent visible wrinkles.

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

The elastic member maintains improved flatness and folding reliability by distributing stress evenly across its layers, preventing deformation and increasing curvature, thus extending the device's lifespan and reliability.

Implementation Method 1

the second layer includes a base material and fibers disposed inside the base material, wherein the fibers are disposed while extending in the second direction

Methodology Applied

Scientific EffectFiber reinforcement: Composite Materials

Data Source

PatentUS12600111B2Elastic member and display device comprising same

Publication Date: 2026.04.14 LG INNOTEK CO LTD

AI summary

An elastic member according to an embodiment includes: a first region and a second region, wherein a first direction is defined as a width direction of the elastic member and a second direction defined as a longitudinal direction of the elastic member, wherein the first region is defined as a folding region that is folded with the first direction as a folding axis, and the second region is defined as an unfolding region, wherein the elastic member includes a first layer and a second layer on the first layer; wherein the second layer includes a base material and fibers disposed inside the base material, wherein the fibers are disposed while extending in the second direction.