Flexible Display Window Member with Layered Modulus Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Flexible display devices face challenges in durability and bending stiffness, particularly when curved or folded, as existing designs often compromise between foldability and structural strength.
Innovation Solution
A flexible display device with a window member composed of multiple base layers, where the first base layer has a higher modulus of elasticity than the second base layer, with varying thicknesses in the folding and peripheral areas to enhance foldability and strength, respectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single-layer window member is used, then the structure is simple, but the durability and bending stiffness are insufficient
Solution Approach 1:
The window member is constructed as a composite structure with a first base layer (higher modulus of elasticity) and a second base layer (lower modulus of elasticity). This composite design allows the first base layer to provide strength and rigidity while the second base layer enhances flexibility and durability, resolving the contradiction between structural simplicity and durability.
Solution Approach 2:
The window member is divided into multiple functional layers with distinct properties. The first base layer and second base layer are segmented to perform different functions: the first layer provides structural strength while the second layer improves flexibility and impact resistance, thereby enhancing overall durability without excessive complexity.
2Strength
If the window member has high bending stiffness, then the strength is enhanced, but the foldability deteriorates
Solution Approach 1:
The window member exhibits spatially varying properties through its layered structure. The first base layer with higher modulus of elasticity provides local strength where needed, while the second base layer with lower modulus of elasticity provides local flexibility in the folding area. This local differentiation allows the window member to maintain overall strength while enabling foldability in specific regions.
Solution Approach 2:
By combining materials with different modulus of elasticity values in a layered composite structure, the window member achieves a balance between strength and flexibility. The higher-modulus first base layer ensures structural integrity while the lower-modulus second base layer facilitates bending and folding operations.
3Ease of operation
If the base layer with small modulus of elasticity has high ratio in folding area, then the foldability is improved, but the external strength is reduced
Solution Approach 1:
The second base layer (lower modulus of elasticity) is designed with a thickness ratio greater than 50% in the folding area to maximize flexibility where bending occurs. Simultaneously, the first base layer (higher modulus of elasticity) maintains sufficient thickness in peripheral areas to provide external strength and protection, achieving local optimization of both foldability and strength.
Solution Approach 2:
The composite layered structure allows the lower-modulus second base layer to dominate in the folding area for enhanced foldability, while the higher-modulus first base layer provides compensating strength in peripheral regions. This spatial distribution of material properties resolves the contradiction between local foldability and overall strength.
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 solution allows for improved durability and reduced bending stiffness, enabling easier folding while maintaining sufficient strength to protect the display panel from external impacts.
Implementation Method 1
The base layers include a first base layer and a second base layer. The second base layer is overlapped with the first base layer and has a modulus of elasticity smaller than a modulus of elasticity of the first base layer.
Data Source
AI summary
A flexible display device includes a flexible display panel and a window member. The flexible display device includes a folding area and a peripheral area disposed adjacent to the folding area. The window member includes at least first and second base layers. The second base layer is overlapped with the first base layer and has a modulus of elasticity that is higher than that of the first base layer. A thickness of a first portion of the first base layer, which is overlapped with the folding area, is greater than a thickness of a second portion of the first base layer, which is overlapped with the peripheral area.