Flexible Display Notch Pattern Stress Alignment

Solution Overview

Problem

Flexible display devices face issues with layer de-lamination and cracking due to stress from repeated folding, as the maximum stress line is not parallel to the folding line, leading to operational and visual defects.

Innovation Solution

A display device design with a folding area and non-folding areas, featuring notch patterns in the overlapping areas of the non-display and folding regions, which guides the folding behavior to align the maximum stress line parallel to the folding line, reducing stress concentration and layer separation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If flexible display devices are folded repeatedly, then the device is more portable and adaptable, but layer de-lamination and cracking occur due to stress concentration

Engineering Contradiction:

Improvefolding capabilityVSAvoidlayer integrity

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The display device is divided into distinct functional areas: a first non-folding area, a folding area, and a second non-folding area. This segmentation allows the folding area to accommodate bending stress while the non-folding areas maintain structural integrity and house critical components, preventing layer de-lamination and cracking during repeated folding operations.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the display device are assigned different functional properties: the folding area is designed to be flexible and accommodate bending, while the non-folding areas maintain rigidity to protect critical components. This local differentiation of mechanical properties allows the device to fold without compromising overall structural integrity.

Inventive Principle:

Principle #3Local quality

2Ease of operation

If the maximum stress line is not parallel to the folding line, then folding is possible, but stress concentration causes de-lamination and cracking

Engineering Contradiction:

Improvefolding operationVSAvoidlayer bonding strength

Core Design Contradiction:

Ease of operationVSStrength

Solution Approach 1:

The device structure is pre-configured with a folding area positioned between two non-folding areas, with the maximum stress line parallel to the folding line. This preliminary structural arrangement ensures that during folding operations, stress is evenly distributed along the folding line rather than concentrating at specific points, preventing de-lamination and cracking before they can occur.

Inventive Principle:

Principle #10Preliminary action

3Volume of moving object

If critical components are placed in the folding area, then the device is more compact, but the components are damaged by folding stress

Engineering Contradiction:

Improvedevice compactnessVSAvoidcomponent functionality

Core Design Contradiction:

Volume of moving objectVSReliability

Solution Approach 1:

The display device is divided into distinct functional areas: a first non-folding area, a folding area, and a second non-folding area. This segmentation allows the folding area to accommodate bending stress while the non-folding areas maintain structural integrity and house critical components, preventing layer de-lamination and cracking during repeated folding operations.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS10461274B2Flexible display device including notch pattern in folding area and flexible electronic device including the same

Publication Date: 2019.10.29 SAMSUNG DISPLAY CO LTD

AI summary

Disclosed is a display device, includes a display area configured to display an image, a non-display area adjacent to the display area, a folding area configured to bend based on a folding line, and a first non-folding area and a second non-folding area positioned at opposite sides of the folding area. A first notch pattern is formed in an overlapping area of the non-display area and the folding area.