Cover Plate with Low Stiffness Patterns for Foldable Displays

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Solution Overview

Problem

Foldable display devices suffer from damage, such as cracks, in the cover window and backplate due to repeated folding and unfolding, leading to decreased display quality and reliability.

Innovation Solution

A cover plate with alternating low stiffness and high stiffness regions, arranged in a specific pattern to absorb stress during folding and unfolding, providing protection while allowing for flexible folding in multiple directions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a rigid cover window is used to protect the display panel, then protection strength is improved, but damage from repeated folding occurs

Engineering Contradiction:

Improveprotection strengthVSAvoiddamage resistance

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The cover plate is divided into multiple regions with different stiffness characteristics - rigid regions for protection and flexible regions for folding, preventing cracks during repeated folding operations

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the cover plate have different local stiffness properties, with rigid portions providing protection and flexible portions enabling folding, resolving the contradiction between strength and reliability

Inventive Principle:

Principle #3Local quality

2Adaptability or versatility

If a flexible structure is used to enable folding, then portability is improved, but protection capability deteriorates

Engineering Contradiction:

Improvefolding capabilityVSAvoidprotection capability

Core Design Contradiction:

Adaptability or versatilityVSStrength

Solution Approach 1:

The cover plate combines rigid and flexible segments in a single structure, allowing the flexible portions to enable folding while rigid portions maintain protection capability

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The cover plate uses a composite structure with regions of different stiffness, combining the benefits of rigid materials (protection) and flexible materials (folding capability) in one component

Inventive Principle:

Principle #40Composite materials

3Strength

If the cover plate is made entirely rigid, then protection is improved, but stress concentration during folding increases

Engineering Contradiction:

ImproveprotectionVSAvoidstress concentration

Core Design Contradiction:

StrengthVSStress or pressure

Solution Approach 1:

Flexible regions are strategically placed in areas prone to stress concentration during folding, while rigid regions provide protection in areas requiring strength, optimizing the stress distribution

Inventive Principle:

Principle #3Local quality

Data Source

PatentEP3330833B1Cover plate and foldable display device including the same

Publication Date: 2021.09.01 LG DISPLAY CO LTD

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AI summary

An embodiment of the present invention provides a cover plate including a high stiffness base and a plurality of low stiffness patterns arranged in a hole or an indentation of the high stiffness base. The cover plate and a foldable display device including the cover plate can be foldable in various directions.