Foldable Display Optical Film Moisture Sealing via Adhesive Protrusions

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Bendable or foldable display devices face issues with moisture penetration into optical films, leading to a loss of external light reflection prevention function and image quality deterioration due to tensile or compressive forces during bending or folding.

Innovation Solution

A display device configuration featuring a display panel with an optical film including a 1/4 wavelength phase retarder and a polarizer, sealed by first and second adhesive layers with protrusion regions that contact each other, preventing moisture penetration and maintaining external light reflection prevention.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the display device is made bendable or foldable to improve portability and reduce volume, then the display device can be viewed at various angles and portability is improved, but tensile or compressive forces occur during bending or folding which cause layers to float and moisture to penetrate into the optical film

Engineering Contradiction:
ImproveportabilityVSAvoidmoisture resistance
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The adhesive layers are extended in the third dimension by forming protrusions that extend beyond the surface of the optical film. This dimensional extension allows the adhesive to bridge gaps and seal edges more effectively, preventing moisture penetration while maintaining the bendable structure.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The adhesive layers are applied to the optical film before the device is bent or folded, and the protrusions are formed in advance to cover potential floating regions. This preliminary sealing action prevents moisture from penetrating into the optical film when bending or folding occurs during normal use.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If adhesive layers are applied to prevent moisture penetration, then moisture resistance is improved, but the adhesive layers may interfere with the optical performance or add complexity to the structure

Engineering Contradiction:
Improvemoisture resistanceVSAvoidstructure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The adhesive layers serve multiple functions: they bond the optical film to adjacent layers, seal the edges to prevent moisture penetration, and the protrusions provide additional sealing without requiring separate components. This multi-functionality reduces overall structural complexity while maintaining moisture resistance.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If protrusion regions are added to the adhesive layers to enhance sealing, then moisture resistance is improved, but manufacturing precision requirements increase

Engineering Contradiction:
Improvemoisture resistanceVSAvoidprotrusion formation
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The protrusions are formed by controlling the application parameters of the adhesive layers, such as viscosity, application pressure, and curing conditions. By optimizing these parameters, the protrusions can be consistently formed with adequate dimensions to seal the optical film edges without requiring extremely tight manufacturing tolerances.

Inventive Principle:
Principle #35Parameter changes

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 effectively prevents moisture ingress into the optical film, maintaining image quality and external light reflection prevention, even when the display device is bent or folded, thereby enhancing the overall image quality and durability.

Implementation Method 1

a first adhesive layer between the display panel and the optical film and contacting a first surface of the optical film; and a second adhesive layer on the optical film and contacting a second surface of the optical film

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 2

an optical film over the display panel and including at least one phase retarder and a polarizer

Methodology Applied
Scientific EffectPhase retardation:

Implementation Method 3

an optical film over the display panel and including at least one phase retarder and a polarizer

Methodology Applied
Scientific EffectPolarization: Polarisation

Data Source

PatentEP3312900B1Display device
Publication Date: 2023.05.10 SAMSUNG DISPLAY CO LTD
  • EP3312900B1 patent drawingFigure 1
  • EP3312900B1 patent drawingFigure 2
  • EP3312900B1 patent drawingFigure 3

AI summary

A display device (1) includes: a display panel (100) to display an image; an optical film (200) over the display panel (100) and including at least one phase retarder (210) and a polarizer (220); a first adhesive layer (310) between the display panel (100) and the optical film (200) and contacting a first surface of the optical film (200); and a second adhesive layer (320) on the optical film (200) and contacting a second surface of the optical film (200) opposite the first surface, and the first adhesive layer (310) and the second adhesive layer (320) contact each other.