Dual-Sided Electrophoretic Display Identical Imaging

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Solution Overview

Problem

Conventional electrophoretic displays face issues with long-term image quality due to particle settling, and they often display complementary rather than similar images on opposing surfaces, limiting their usage in architectural applications where dual-sided identical imaging is desired.

Innovation Solution

A dual-sided electrophoretic display is developed using encapsulated dispersion fluid layers with charged particles, where the first and second layers have similar colored particles but opposite charges, or multi-chromal particles with matching surface charges, positioned between light-transmissive electrodes to maintain similar optical states on both sides by adjusting electrode potentials.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional electrophoretic displays use single-layer encapsulated particles, then the device structure is simple, but the display shows complementary images on opposing surfaces rather than identical images

Engineering Contradiction:

Improvedual-sided identical imaging capabilityVSAvoiddisplay structure

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The display is divided into two separate encapsulated layers, each containing electrophoretic particles with opposite charges. The first layer contains particles with positive charge and the second layer contains particles with negative charge. This segmentation allows each layer to be independently controlled by respective electrodes, enabling identical images to be displayed on both sides of the display simultaneously.

Inventive Principle:

Principle #1Segmentation

2Reliability

If electrophoretic displays use charged particles in fluid medium, then the display can change optical states, but particles settle over time degrading long-term image quality

Engineering Contradiction:

Improvelong-term image qualityVSAvoidparticle distribution stability

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The display system applies periodic addressing pulses to both the first and second electrodes to maintain particle distribution. The controller periodically sends voltage pulses to counteract gravitational settling, redistributing particles uniformly within their respective encapsulated layers. This periodic action prevents particle aggregation and maintains consistent display quality over extended periods.

Inventive Principle:

Principle #19Periodic action

3Adaptability or versatility

If dual-sided electrophoretic display uses two layers with opposite charged particles, then identical images can be displayed on both surfaces, but the device complexity increases

Engineering Contradiction:

Improvedual-sided identical imaging capabilityVSAvoidnumber of layers and electrodes

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The controller integrates the driving logic for both layers into a single control unit that coordinates voltage application to the first and second electrodes. The encapsulated layers are combined in a stacked configuration where the first encapsulated layer and second encapsulated layer are positioned adjacent to each other, sharing a common substrate structure. This merging approach enables identical dual-sided imaging while minimizing overall device complexity through coordinated control and integrated structure.

Inventive Principle:

Principle #5Merging (Combining)

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 enables dual-sided electrophoretic displays to show identical optical states on both surfaces, improving long-term image quality and addressing the issue of complementary images, thus enhancing their suitability for architectural applications.

Implementation Method 1

a first and second layer of encapsulated dispersion fluid containing charged particles and a front and rear light-transmissive electrode

Methodology Applied

Scientific EffectElectrophoresis: Electrophoresis

Implementation Method 2

The charged particles within the first layer may have a color similar to and a charge opposite of the charged particles within the second layer

Methodology Applied

Scientific EffectElectro-optic effect: Electro-Optic Effects

Data Source

PatentUS10509294B2Dual sided electrophoretic display

Publication Date: 2019.12.17 E INK CORP

AI summary

An image display medium includes a first and second layer of encapsulated dispersion fluid containing charged particles and a front and rear light-transmissive electrode. The first layer is positioned between the front light-transmissive electrode and the second layer and the second layer is position between the first layer and the rear light-transmissive electrode. The charged particles within the first layer have a color similar to and a charge opposite of the charged particles within the second layer. Alternatively, the charged particles within the first layer may have a color and a charge similar to the charged particles within the second layer and the display medium includes a common conductor positioned between the first and second layer that is configured to drive the charged particles in the first and second layer.