Foldable Display Film Stack for Impact Resistance and Flexibility
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing flexible display devices lack sufficient impact resistance and folding properties, limiting their durability and usability.
Innovation Solution
A display device design featuring multiple films with varying moduli and adhesive layers, including a first film with high modulus, a second film with intermediate modulus, and a third film with low modulus, along with protective films at the bottom, enhances impact resistance and folding capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a single rigid protective film is used on the display module, then impact resistance is improved, but folding properties deteriorate
Solution Approach 1:
The protective structure is divided into multiple film layers (first film, second film, third film) with different moduli. The first film (high modulus, 2-4 GPa) provides impact resistance, while the second film (intermediate modulus, 0.5-2 GPa) and third film (low modulus, 0.1-0.5 GPa) enable flexible deformation during folding. This segmentation allows each layer to perform its specific function, resolving the contradiction between rigidity for protection and flexibility for folding.
Solution Approach 2:
The invention uses a composite multi-layer film structure where each layer has different mechanical properties (modulus values). The combination of high-modulus, intermediate-modulus, and low-modulus films creates a composite material system that simultaneously achieves impact resistance (from the high-modulus first film) and folding capability (from the flexible second and third films).
2Reliability
If multiple films with different moduli are used, then both impact resistance and folding properties are improved, but device complexity increases
Solution Approach 1:
The invention employs thin film structures that inherently provide flexibility and conformability. The multi-layer thin film design allows the display device to achieve reliable folding properties while maintaining a relatively simple overall structure. The thin films can be integrated into the existing display module architecture without requiring complex mechanical components.
Data Source
Figure 1A
Figure 1B
Figure 2A
AI summary
Disclosed is a display device including a display module that has at least one folding area, a first film disposed on the display module and having a first modulus, a second film disposed on the first film, being farther from the display module than the first film, and having a second modulus less than the first modulus, and a third film disposed on the second film, being farther from the display module than the second film, and having a third modulus less than the second modulus. The third modulus is equal to or less than about one-sixth of the first modulus.