Multi-Fold Display Cover Plate Structure for Stiffness and Bendability

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Solution Overview

Problem

Existing foldable electronic devices face challenges in achieving good bendability of bending areas, high unfolding stiffness of non-bending areas, and sufficient impact and compression resistance.

Innovation Solution

A display module with a flexible structure featuring unequal thickness and modulus designs in its cover plate, where the non-bending areas have increased thickness or modulus to enhance stiffness while maintaining bendability and resistance, and cushion layers with varying thickness and modulus to improve impact and compression resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the thickness of the non-bending area is increased to improve stiffness, then the stiffness of the non-bending area is improved, but the bendability of the bending area deteriorates

Engineering Contradiction:
Improvestiffness of non-bending areaVSAvoidbendability of bending area
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

The cover plate is designed with different thicknesses for different areas: the first non-bending area has a greater thickness to provide high stiffness and strength, while the second non-bending area has a smaller thickness. The bending areas have intermediate thickness values that allow for flexible deformation. This local differentiation of thickness enables each area to have the appropriate mechanical properties for its function.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The cover plate is divided into multiple distinct areas (first non-bending area, first bending area, second non-bending area, second bending area, third non-bending area) with different thickness characteristics. This segmentation allows independent optimization of each area's thickness to meet different functional requirements simultaneously.

Inventive Principle:
Principle #1Segmentation

2Strength

If the thickness of the first non-bending area is increased to improve stiffness, then the stiffness is improved, but the overall device thickness increases

Engineering Contradiction:
Improvestiffness of first non-bending areaVSAvoidoverall device thickness
Core Design Contradiction:
StrengthVSVolume of moving object

Solution Approach 1:

The cover plate implements local quality by having the first non-bending area with greater thickness only where needed for stiffness and strength, while other areas have reduced thickness. This localized thickening provides the required mechanical performance without uniformly increasing the overall device thickness.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent transitions from a uniform thickness design to a variable thickness design across different areas of the cover plate. This dimensional variation in the thickness parameter allows optimization of stiffness in specific areas without proportionally increasing the overall device volume.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Stability of the object's composition

If the elastic modulus of the non-bending area is increased to improve rigidity, then the rigidity is improved, but the impact and compression resistance deteriorates

Engineering Contradiction:
Improverigidity of non-bending areaVSAvoidimpact and compression resistance
Core Design Contradiction:
Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

The cushion layer is designed with different elastic moduli for different areas: the first portion (in the first non-bending area) has a greater elastic modulus to provide high rigidity, while the second portion (in the first bending area) has a smaller elastic modulus to provide good impact and compression resistance. This local differentiation allows each area to have appropriate mechanical properties.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The cover plate structure combines multiple layers including the substrate and cushion layer with different material properties. The cushion layer acts as a composite element that provides both rigidity in non-bending areas and shock absorption in bending areas, achieving a balance between rigidity and impact resistance through material composition.

Inventive Principle:
Principle #40Composite materials

Data Source

PatentEP4715790A1Display module and electronic device
Publication Date: 2026.03.25 HUAWEI TECH CO LTD
  • EP4715790A1 patent drawingFigure 1~2
  • EP4715790A1 patent drawingFigure 3
  • EP4715790A1 patent drawingFigure 4

AI summary

A display module (11) and an electronic device that includes the display module (11) are provided, which relate to the field of display technologies. The display module (11) can improve unfolding stiffness and bendability. The display module (11) includes a display (112) and a cover plate (110) disposed on a display surface of the display (112). The display (112) includes at least two bending portions and three non-bending portions. In other words, the display module (11) is a multi-foldable display module (11), and the cover plate (110) is designed to be of an unequal-thickness structure. The cover plate (110) is designed as an unequal-thickness design, so that the non-bending portion has high rigidity, and the bending portion has good bendability.