Display Medium Reflectivity Control for Moire Elimination

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Solution Overview

Problem

Existing display technologies face challenges in minimizing the reflectivity difference between electrode and boundary portions, leading to Moire patterns and deteriorated display quality, especially when displaying black colors.

Innovation Solution

A display medium comprising a first transparent substrate, a second substrate with electrode and boundary portions at specific intervals, a spacing member maintaining a gap, and a particle dispersion liquid with migratory particles, where the reflectivity difference between electrode and boundary portions is minimized through a coat layer or surface treatment, ensuring low reflectivity differences and improved transmittance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If electrode portions and boundary portions are constructed with different materials or structures, then electrical functionality is improved, but reflectivity difference increases causing Moire patterns

Engineering Contradiction:

Improveelectrical functionalityVSAvoidreflectivity difference causing Moire patterns

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by treating electrode portions and boundary portions differently through selective coating. The boundary portions are coated with a light-absorbing material to reduce their reflectivity, while electrode portions maintain their original reflective properties. This localized differentiation allows the system to maintain electrical functionality while compensating for the harmful reflectivity difference that causes Moire patterns.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent converts the harmful reflectivity difference into a beneficial effect by using the boundary portions' lower reflectivity (achieved through coating) to reduce overall light reflection from the electrode structure. This conversion transforms the previously harmful Moire pattern-causing reflectivity variation into a beneficial light-absorbing characteristic that improves display quality.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

2Object-affected harmful factors

If a coat layer is applied to reduce reflectivity difference, then display quality is improved, but manufacturing complexity increases

Engineering Contradiction:

Improvedisplay quality deteriorationVSAvoidmanufacturing complexity

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The coating is applied selectively only to boundary portions rather than the entire surface. This localized approach reduces the amount of coating material needed and simplifies the manufacturing process compared to full-surface coating, while still effectively reducing the reflectivity difference that causes Moire patterns and improves display quality.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent uses a simple, inexpensive light-absorbing coating material that can be easily applied and removed if needed. This disposable-like approach allows for cost-effective implementation of the reflectivity reduction without requiring complex, expensive, or permanent structural modifications to the electrode portions.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

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 reduces the reflectivity difference to 12 percentage points or less, eliminating Moire patterns and enhancing display quality, particularly for black color representation by using a black coat layer or surface treatment on the electrode surfaces.

Implementation Method 1

particles which moves by an electric field formed between the first and second substrates

Methodology Applied

Scientific EffectElectric field: Electric Field

Implementation Method 2

the second substrate has a difference between the reflectivity of the electrode portions and the reflectivity of the boundary portions with respect to light incident from the first substrate side

Methodology Applied

Scientific EffectReflection: Reflection

Implementation Method 3

an electrode surface of each electrode portion facing the first substrate side has a coat layer made of an anodized aluminum alloy

Methodology Applied

Scientific EffectAnodization: Anodising

Data Source

PatentUS8630034B2Display medium and display device

Publication Date: 2014.01.14 E INK CORP

AI summary

A display medium of the present invention includes first and second substrates, a spacing member and a particle dispersion liquid. The first substrate is transparent to light. The second substrate is opposite to the first substrate and has plural electrodes placed at an interval. The second substrate has a difference between reflectivity of the electrode portions and reflectivity of plural boundary portions between the electrodes with respect to light incident from the first substrate side. The difference is 12 percentage points or less. The spacing member is placed between the first and second substrates at another interval, is transparent to light, and keeps a gap between the first and second substrates. The particle dispersion liquid is filled between the first and second substrates, and includes particles moving in a direction of an electric field formed between the first and second substrates and a dispersion medium.