Flexible Display Device Stress Neutral Surface Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional flexible display devices face challenges with scratch resistance, stable folding and unfolding characteristics, and image distortion due to their structure, which limits their application in foldable mobile devices.
Innovation Solution
The flexible display device incorporates a stress neutral surface between the inner hard coating layer and the display panel, with a touch electrode layer directly on the inner surface of the transparent substrate, and includes a polarization panel between the protective panel and the display panel, featuring transparent fine particles in the adhesive layers arranged perpendicular to the folding direction to reduce stress and distortion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a rigid structure is used to maintain display quality, then display performance is improved, but flexibility and wearability are worsened
Solution Approach 1:
The patent applies flexible thin films throughout the display structure, including the encapsulation layer, buffer layer, and electrode layers. These thin film structures enable the entire display device to be flexible while maintaining display performance, directly resolving the contradiction between rigidity for display quality and flexibility for wearability.
Solution Approach 2:
The patent implements a dynamic flexible display structure that can adapt to different wearing states. The display device transitions from a rigid configuration to a flexible,可穿戴 configuration, allowing the display to dynamically adjust its form factor based on usage requirements.
2Adaptability or versatility
If the display device is made flexible for wearability, then adaptability is improved, but structural stability and protection are worsened
Solution Approach 1:
The patent employs composite material structures combining organic and inorganic layers (e.g., alternating organic encapsulation layers with inorganic buffer layers). This composite approach provides both flexibility for wearability and structural stability for protection, resolving the contradiction between adaptability and strength.
Solution Approach 2:
The encapsulation structure includes buffer layers positioned to preemptively protect the organic light-emitting layer from environmental damage. This beforehand cushioning approach ensures structural stability and protection while maintaining the flexible form factor needed for wearability.
3Ease of manufacture
If the organic light-emitting layer is exposed for flexibility, then ease of manufacture is improved, but reliability against environmental damage is worsened
Solution Approach 1:
The patent uses flexible thin film encapsulation layers that conformally cover the organic light-emitting layer. These thin films provide effective barrier protection against moisture and oxygen while maintaining the manufacturing simplicity associated with flexible display fabrication processes.
Solution Approach 2:
The encapsulation structure employs a nested multi-layer configuration where organic and inorganic layers are alternately stacked. This nested structure provides enhanced protection against environmental damage while maintaining ease of manufacture through sequential deposition processes.
Data Source
Figure 1~3
Figure 4~8
Figure 9~11
AI summary
A plurality of panels include: a display panel; and a protective panel that is disposed outside the display panel, and includes a transparent substrate and an outer hard coating layer and an inner hard coating layer that are respectively formed on an outer surface and an inner surface of the transparent substrate, and each have a hardness greater than a hardness of the transparent substrate. A thickness of the outer hard coating layer is greater than a thickness of the inner hard coating layer, and a stress neutral surface of the flexible display device is configured so that a compressive stress is applied to the inner hard coating layer when the flexible display device is bent.