Foldable Display Reinforcement Part Stress Mitigation

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Solution Overview

Problem

Flexible display apparatuses, such as foldable displays, are prone to crack occurrence when folded due to tensile stress, which can damage the display elements and compromise the structural integrity of the device.

Innovation Solution

A display apparatus design that includes a substrate with display elements, an encapsulation layer, and a reinforcement part arranged in the folded area, featuring varying thicknesses and materials to alleviate tensile forces, with the reinforcement part disposed on the encapsulation layer and potentially in the peripheral area to prevent crack propagation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a foldable display apparatus is folded, then flexibility and portability are improved, but crack occurrence and damage to display elements increase due to tensile stress in the folded area

Engineering Contradiction:
ImproveflexibilityVSAvoidcrack occurrence
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

A reinforcement part is disposed on the encapsulation layer in advance in the folded area before the display apparatus is folded. This reinforcement part has a thickness greater than that of the encapsulation layer, providing preemptive structural support to withstand tensile stress during folding operations, thereby preventing crack formation while maintaining flexibility

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The reinforcement part is selectively disposed only in the folded area where tensile stress occurs during folding, rather than uniformly across the entire display apparatus. This localized reinforcement provides targeted protection to the vulnerable region while maintaining flexibility in other areas, preventing crack occurrence without compromising overall adaptability

Inventive Principle:
Principle #3Local quality

2Ease of manufacture

If the reinforcement part has uniform thickness, then manufacturing is simplified, but stress distribution in the folded area is insufficient to prevent crack propagation

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidstress distribution
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The reinforcement part features a thickness that varies in the folded area, with greater thickness at locations experiencing higher tensile stress and progressively thinner sections toward areas with lower stress. This non-uniform thickness distribution optimizes stress mitigation where needed most while reducing material usage and manufacturing complexity compared to uniformly thick reinforcement across the entire folded area

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP4203658A1Display apparatus and method of manufacturing the display apparatus
Publication Date: 2023.06.28 SAMSUNG DISPLAY CO LTD
  • EP4203658A1 patent drawingFigure 1
  • EP4203658A1 patent drawingFigure 2
  • EP4203658A1 patent drawingFigure 3

AI summary

A display apparatus which is in-folded or out-folded in a folded area thereof includes a substrate, a plurality of display elements disposed over the substrate, an encapsulation layer sealing the plurality of display elements, and a reinforcement part disposed on the encapsulation layer and arranged in the folded area.