Foldable Display Adhesive Layer Impact Protection

Solution Overview

Problem

Foldable display devices face challenges in protecting internal elements from external impacts due to the use of flexible plastic covers, which compromise the protection of internal components.

Innovation Solution

A foldable display device design incorporating a thin film transistor substrate with a flexible first adhesive layer and a rigid second adhesive layer outside the first layer, except at the folding area, to absorb and distribute external impacts while maintaining flexibility for folding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a flexible plastic cover is used as a cover window to enable folding function, then flexibility and folding capability are improved, but the protection function from external impact is weakened

Engineering Contradiction:

Improvefolding capabilityVSAvoidexternal impact protection

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The adhesive layer is divided into two distinct segments: a first adhesive layer made of flexible material for the display area, and a second adhesive layer made of rigid material for the non-display area. This segmentation allows each part to perform its specific function - the flexible portion enables folding while the rigid portion provides impact protection.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the adhesive layer are assigned different material properties to match local functional requirements. The display area requires flexibility for folding operations, while the non-display area requires rigidity for impact resistance. This local quality differentiation resolves the contradiction between folding capability and impact protection.

Inventive Principle:

Principle #3Local quality

2Object-affected harmful factors

If a rigid material is used to protect internal elements from external impact, then protection function is improved, but flexibility and folding capability are worsened

Engineering Contradiction:

Improveexternal impact protectionVSAvoidfolding capability

Core Design Contradiction:

Object-affected harmful factorsVSAdaptability or versatility

Solution Approach 1:

The adhesive layer is divided into two distinct segments: a first adhesive layer made of flexible material for the display area, and a second adhesive layer made of rigid material for the non-display area. This segmentation allows each part to perform its specific function - the flexible portion enables folding while the rigid portion provides impact protection.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the adhesive layer are assigned different material properties to match local functional requirements. The display area requires flexibility for folding operations, while the non-display area requires rigidity for impact resistance. This local quality differentiation resolves the contradiction between folding capability and impact protection.

Inventive Principle:

Principle #3Local quality

3Strength

If adhesive layers are arranged to provide impact protection, then structural strength is improved, but manufacturing complexity increases

Engineering Contradiction:

Improvestructural integrityVSAvoidmanufacturing complexity

Core Design Contradiction:

StrengthVSEase of manufacture

Solution Approach 1:

The protective function and adhesive function are merged into a single integrated adhesive layer structure. The multi-layer adhesive configuration combines both structural support and bonding capabilities, eliminating the need for separate protective components and reducing overall manufacturing complexity.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The adhesive layer structure serves multiple functions simultaneously: it provides impact protection, maintains structural integrity during folding, and adheres the cover window to the display device. This multi-functionality reduces the number of separate components needed and simplifies the manufacturing process.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS10727425B2Foldable display device capable of preventing damage on internal elements caused by external impact and method of manufacturing the same

Publication Date: 2020.07.28 LG DISPLAY CO LTD

AI summary

A foldable display device and its manufacturing method are disclosed, in which a flexible cover plastic is used as a cover window and internal elements may be prevented from being damaged due to external impact. The foldable display device comprising a thin film transistor substrate; a first adhesive layer arranged on the thin film transistor substrate; a second adhesive layer arranged outside the first adhesive layer on the thin film transistor substrate; and a touch substrate arranged on the first and second adhesive layers, wherein the second adhesive layer includes a rigid material and is arranged on areas outside the first adhesive layer except a folding area where the thin film transistor substrate is folded.