Electrophoretic Display Module Stress-Free Casing Fixation

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Solution Overview

Problem

Existing electrophoretic display (EPD) devices face issues with stress application and reduced reliability when the EPD laminate is fixed to a casing, leading to deteriorated image display quality and electrical characteristics, especially when bent or curved.

Innovation Solution

Incorporating conductive ITO layers at both ends of the EPD laminate and retentive portions in the casing that contact and retain the conductive portions, allowing for stress-free fixation and improved sealing reliability, enabling high display quality and electrical characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the EPD laminate is fixed to the casing using conventional positioning structures, then the laminate is retained in position, but stress is applied to the contact portion deteriorating image display quality and reducing sealing reliability

Engineering Contradiction:

Improvesealing reliabilityVSAvoidstress application

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces conductive portions (ITO layers) as intermediary elements between the retentive portions and the EPD laminate. These conductive portions serve as a mediator that absorbs positioning stresses, preventing direct stress transmission to the EPD laminate while maintaining electrical connectivity and positioning functionality.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent segments the contact interface by introducing separate conductive portions (ITO layers) that are distinct from the EPD laminate itself. This segmentation allows the positioning function to be separated from the display function, enabling independent optimization of stress distribution and electrical performance.

Inventive Principle:

Principle #1Segmentation

2Shape

If the EPD laminate is bent and fixed to the casing, then curved exterior surfaces are achieved, but local stress is applied to the EPD laminate deteriorating image display quality and electrical characteristics

Engineering Contradiction:

Improvecurved exterior surfaceVSAvoidlocal stress

Core Design Contradiction:

ShapeVSObject-affected harmful factors

Solution Approach 1:

The conductive portions act as stress-absorbing intermediaries that decouple the mechanical stress from the EPD laminate during bending. This allows the laminate to be bent into curved shapes while the conductive portions absorb the localized stresses, preventing deterioration of display quality and electrical characteristics.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the mechanical parameters of the system by introducing flexible conductive ITO layers that can deform with the bent laminate. This parameter change allows the conductive portions to accommodate curvature-induced stresses without transmitting damaging forces to the EPD laminate.

Inventive Principle:

Principle #35Parameter changes

3Manufacturing precision

If retentive portions contact the EPD laminate surface directly, then positioning is achieved, but the contact area is large applying excessive stress to the display surface

Engineering Contradiction:

Improvepositioning precisionVSAvoidexcessive stress

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The conductive portions serve as intermediary contact elements that distribute the positioning load over a larger area without concentrating stress on the EPD laminate display surface. This intermediary layer maintains precise positioning while reducing stress density through increased contact area distribution.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 prevents stress application to the display surface, enhances sealing reliability, and maintains high display quality and electrical characteristics even when the laminate is bent or fixed to curved casings, applicable to various devices with curved shapes.

Implementation Method 1

conductive portions made of indium tin oxide (ITO) layers located at both ends of the EPD laminate

Methodology Applied

Scientific EffectElectrical Conduction: Conduction (electrical)

Implementation Method 2

retentive portions that are provided in the casing and retain the EPD laminate. The retentive portions contact and retain at least a part of the conductive portions to position the EPD laminate with respect to the casing

Methodology Applied

Scientific EffectMechanical Retention: Mechanical Fastener

Implementation Method 3

An electrophoretic display (EPD) device includes an electrophoretic laminate that employs an electrophoresis phenomenon in which particles dispersed in a solvent are moved by an applied voltage

Methodology Applied

Scientific EffectElectrophoresis: Electrophoresis

Data Source

PatentUS7548366B2Electrophoretic display module and electrophoretic display device

Publication Date: 2009.06.16 E INK CORP

AI summary

An electrophoretic display (EPD) module includes an EPD laminate, conductive portions made of ITO layers which are located at both ends of the EPD laminate, a casing that encloses the EPD laminate, and retentive portions that are provided in the casing and retain the EPD laminate, in which the retentive portions contact and retain at least a part of the conductive portions to position the EPD laminate with respect to the casing.