Segmented Glass Cover for Foldable Displays
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Foldable electronic devices face challenges in protecting their displays from damage during bending and unfolding, as existing materials lack sufficient flexibility and durability to prevent cracking.
Innovation Solution
A display cover layer with a strip-shaped bendable portion made from a material with a lower modulus of elasticity than the surrounding portions, combined with chemical strengthening to create a shallower compressive surface stress layer, enhances flexibility and resistance to damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a uniform glass cover layer is used across the entire display, then the display maintains consistent protective strength and structural integrity, but the glass cannot bend without cracking when the device is folded
Solution Approach 1:
The display cover glass is divided into three distinct portions: a first portion, a second portion, and a third portion. The second portion is specifically designed with different material properties (lower modulus of elasticity) to enable bending, while the first and third portions maintain higher strength for protection. This segmentation allows the glass structure to both protect the display and accommodate folding movements without cracking.
Solution Approach 2:
Different portions of the glass cover layer are assigned different material qualities tailored to their specific functional requirements. The second portion (bendable portion) has a lower modulus of elasticity to facilitate bending, while the first and third portions have higher modulus of elasticity for structural strength. This local differentiation of material properties resolves the contradiction between overall strength and localized flexibility.
2Adaptability or versatility
If the bendable portion is made thinner to facilitate bending, then flexibility improves, but the protective capability and resistance to damage decrease
Solution Approach 1:
The thickness parameter of the glass is varied across different portions to optimize both bending flexibility and protective strength. The bendable second portion is made thinner to enable flexibility, while the first and third portions are made thicker to provide enhanced protection. This parameter variation resolves the contradiction by allocating thickness according to functional needs rather than using a uniform thickness throughout.
3Strength
If chemical strengthening is applied to increase surface compressive stress, then the glass becomes more resistant to cracking, but the bending flexibility is reduced
Solution Approach 1:
Chemical strengthening treatment is applied selectively to different portions of the glass cover layer. The first and third portions receive full chemical strengthening to maximize crack resistance, while the second portion receives reduced or no chemical strengthening to preserve its bending flexibility. This segmented application of strengthening treatment resolves the contradiction between overall crack resistance and localized flexibility.
Solution Approach 2:
The degree of chemical strengthening varies by location to match functional requirements. Areas requiring high strength (first and third portions) receive deeper and more intense compressive stress layers, while the bendable area (second portion) receives shallower or reduced compressive stress to maintain flexibility. This local differentiation of strengthening intensity optimizes both protection and flexibility.
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 effective bending and unfolding of electronic devices without damaging the display cover layer, maintaining image quality and user privacy while adhering to privacy regulations.
Implementation Method 1
The second portion may be formed from a glass with a lower modulus of elasticity than the first and third portions
Implementation Method 2
The second portion may also be thinner than the first and third portions and may be characterized by a compressive surface stress layer that is shallower than compressive surface stress layers in the first and third portions
Data Source
AI summary
An electronic device may have a display and may be configured to fold about a bend axis that overlaps the display. The display may have a display cover layer having first, second, and third portions that are joined side-by-side. The second portion may have a strip shape that extends along the bend axis and may be configured to bend as the first and third portions are folded towards each other. The second portion may be formed from a different material than the first and third portions to facilitate bending. The second portion may also be characterized by a compressive stress layer that is shallower than compressive stress layers on the first and third portions.