Electrophoretic Smart Glass Layout for Low-Haze Visible Grid

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Solution Overview

Problem

Existing electrophoretic devices struggle to achieve transparent light states with glass-like quality, minimal haze, and a perceivable grid or pattern that is aesthetically pleasing, while effectively attenuating light in other states.

Innovation Solution

The device employs a polymer structure that defines distinct areas for concentrated charged particles, allowing both transparent and attenuating areas to be visibly resolved, with a grid-like pattern in the transparent state, and minimizes integration of particle color or haze by selecting appropriate scales and designs to enhance optical quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If microstructure size is reduced to be invisible to the eye (subtending less than one arc minute), then optical clarity and glass-like quality are improved, but the device cannot provide a visible grid or pattern in the transparent state

Engineering Contradiction:
Improveoptical clarityVSAvoidvisible grid pattern
Core Design Contradiction:
Illumination intensityVSLoss of information

Solution Approach 1:

The device divides the display area into discrete pixel regions separated by visible grid lines. Each pixel is a distinct functional unit that can be independently controlled, and the grid lines are deliberately made visible (subtending more than two arc minutes) to provide a perceivable structure in the transparent state, resolving the contradiction between optical clarity and visible pattern

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the device have different optical properties: pixel areas are optimized for light transmission and display content, while grid line areas are designed to be visible and provide structural definition. This local differentiation allows simultaneous achievement of glass-like clarity in pixel regions and visible grid pattern in separator regions

Inventive Principle:
Principle #3Local quality

2Illumination intensity

If charged particles are concentrated in discrete areas to form transparent apertures, then light transmission is improved, but a perceivable tint corresponding to the color of charged particles remains visible

Engineering Contradiction:
Improvelight transmissionVSAvoidperceivable tint
Core Design Contradiction:
Illumination intensityVSObject-generated harmful factors

Solution Approach 1:

The harmful tint effect is extracted and isolated to the grid line regions, while the pixel regions maintain neutral optical properties. The charged particles are selectively positioned such that their colorant is concentrated in grid areas rather than pixel areas, removing the tint from the functional display regions

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The grid lines act as intermediary elements that contain the colorant particles, serving as a buffer between the transparent pixel regions and the viewer. This intermediary structure absorbs the potentially harmful tint effect while preserving the light transmission and clarity of the pixel areas

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of manufacture

If the pitch and size of transparent areas and obstructions are maximized within resolution limits, then manufacturing is simplified, but diffraction and haze increase

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoiddiffraction and haze
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The device optimizes the pitch and dimensional parameters of pixels and grid lines to specific ranges that balance manufacturing ease with optical performance. The pitch is set large enough for simple manufacturing but small enough to minimize diffraction, and grid line widths are carefully controlled to provide visibility without excessive haze

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 provides clear glass-like transparency with a visible, aesthetically acceptable grid in the transparent state and effective light attenuation in the other state, reducing diffraction and minimizing perceptible tint or haze.

Implementation Method 1

The electrophoretic ink's charged particles respond to an applied electrical field to move between light states

Methodology Applied
Scientific EffectElectrophoresis: Electrophoresis

Data Source

PatentEP4038452B1Electrically-actuated variable transmission film having very low haze and a visible grid in a clear state
Publication Date: 2026.04.22 E INK CORP
  • EP4038452B1 patent drawingFigure 1a~1c
  • EP4038452B1 patent drawingFigure 2a~2b
  • EP4038452B1 patent drawingFigure 3~4

AI summary

A light attenuator that provides transparent light states and absorbing dark states for use in selectively controlling light, especially for smart glass applications. The light attenuator includes abutting areas of attenuation and transparency that form a repeat pattern or a quasi-repeat pattern. The attenuating areas are visible when the light attenuator is in the light state, but the repeat pattern is sufficiently large that a viewer looks through the attenuator and sees no haze.