Flexible Display Window With Holes And Buffer Layer

Solution Overview

Problem

Flexible display devices require a balance between flexibility and impact resistance, with existing solutions struggling to achieve both durability and a small curvature radius effectively.

Innovation Solution

A window for flexible display devices is designed with a specific structure, including a base film with holes, a buffer layer, and a hard coated layer, which enhances impact resistance by controlling the thickness and modulus of the layers, and using a filler with a lower modulus than the base film to disperse stress, while maintaining a small curvature radius.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a thick and rigid structure is used to improve impact resistance, then durability is improved, but flexibility and curvature radius deteriorate

Engineering Contradiction:

Improveimpact resistanceVSAvoidflexibility

Core Design Contradiction:

StrengthVSAdaptability or versatility

Solution Approach 1:

The window structure is divided into multiple functional layers: a first film layer (110) with holes for flexibility, a buffer layer (130) for impact absorption, and a hard coated layer (140) for surface protection. This segmentation allows each layer to perform its specific function independently, achieving both impact resistance and flexibility.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent uses composite material construction combining different materials with complementary properties: flexible polymer materials for the first and second films, viscoelastic buffer material for the buffer layer, and hard coating material for the hard coated layer. This composite structure enables simultaneous achievement of flexibility, impact resistance, and surface durability.

Inventive Principle:

Principle #40Composite materials

2Strength

If a thick and rigid structure is used to improve impact resistance, then durability is improved, but curvature radius deteriorates

Engineering Contradiction:

Improveimpact resistanceVSAvoidcurvature radius

Core Design Contradiction:

StrengthVSShape

Solution Approach 1:

The window structure is divided into multiple functional layers: a first film layer (110) with holes for flexibility, a buffer layer (130) for impact absorption, and a hard coated layer (140) for surface protection. This segmentation allows each layer to perform its specific function independently, achieving both impact resistance and flexibility.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent employs thin film structures (first film 110, second film 120) with controlled thicknesses (10-250 μm for first film, 10-60 μm for second film) that maintain flexibility while providing necessary protection. The holes in the first film (5-50% volume) further enhance flexibility while the buffer layer provides impact resistance, enabling small curvature radius.

Inventive Principle:

Principle #30Flexible shells and thin films

3Strength

If the window thickness is increased to improve impact resistance, then durability is improved, but the overall device thickness exceeds predetermined range

Engineering Contradiction:

Improveimpact resistanceVSAvoidwindow thickness

Core Design Contradiction:

StrengthVSLength of stationary object

Solution Approach 1:

The patent optimizes the thickness parameters of each layer within specific ranges: first film (10-250 μm), second film (10-60 μm), buffer layer (10-30 μm), and hard coated layer (10-60 μm). By carefully controlling these parameters, the total window thickness is kept within 100-300 μm, achieving impact resistance while maintaining the overall device within predetermined thickness range.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses composite material construction combining different materials with complementary properties: flexible polymer materials for the first and second films, viscoelastic buffer material for the buffer layer, and hard coating material for the hard coated layer. This composite structure enables simultaneous achievement of flexibility, impact resistance, and surface durability.

Inventive Principle:

Principle #40Composite materials

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 improves the impact resistance and maintains a small curvature radius, ensuring the flexible display device's thickness is within a predetermined range, effectively protecting against external impacts and maintaining flexibility.

Implementation Method 1

a buffer layer between the first film and the second film to attach a first side of the first film and a first side of the second film

Methodology Applied

Scientific EffectViscoelasticity: Viscoelasticity

Implementation Method 2

a hard coated layer on a second side of the second film

Methodology Applied

Scientific EffectHardness:

Implementation Method 3

A filler with a modulus that is less than a modulus of the base film may be filled in the holes

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentUS10632711B2Window for flexible display device and flexible display device having the same

Publication Date: 2020.04.28 SAMSUNG DISPLAY CO LTD

AI summary

The present disclosure relates to a window for a flexible display device, including: a first film including a transparent base film and a plurality of holes passing through the transparent base film; a second film overlapping the first film; a buffer layer between the first film and the second film to attach a first side of the first film and a first side of the second film; and a hard coated layer on a second side of the second film.