Electrowetting Display Radiation Filter for Photo-bleaching

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Solution Overview

Problem

Electrowetting display devices face a reduction in lifetime due to susceptibility of their fluids to photo-bleaching, which affects the durability and performance of the display.

Innovation Solution

Incorporating a radiation filter configured to block specific wavelengths of radiation that cause deterioration, positioned between the viewing side and the fluids, to reduce exposure and extend the device's operational life while maintaining acceptable display quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of stationary object

If dyes with greater resistance to photo-bleaching are used, then the lifetime of the electrowetting display device is improved, but the cost and complexity of material selection increase

Engineering Contradiction:
Improvelifetime of display deviceVSAvoidcomplexity of material selection
Core Design Contradiction:
Duration of action of stationary objectVSDevice complexity

Solution Approach 1:

A radiation filter layer is introduced as an intermediary component between the viewing side and the electrowetting fluid. This filter selectively blocks harmful radiation wavelengths that cause photo-bleaching of the dye, while allowing visible light to pass through for display functionality. The filter acts as a mediator that protects the dye without requiring changes to the dye itself, thus simplifying material selection while extending device lifetime.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Duration of action of stationary object

If a radiation filter is added to block harmful radiation, then the lifetime of the device is improved, but the device complexity and number of layers increase

Engineering Contradiction:
Improvelifetime of display deviceVSAvoidnumber of layers
Core Design Contradiction:
Duration of action of stationary objectVSDevice complexity

Solution Approach 1:

The radiation filter layer is designed to perform multiple functions simultaneously: it blocks harmful UV and high-energy visible radiation that causes photo-bleaching, while maintaining high transmission in the visible range for display quality. By integrating this multi-functional layer, the patent avoids needing separate components for radiation protection and optical quality, thus managing complexity while achieving extended lifetime.

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

3Reliability

If the radiation filter blocks more wavelengths, then the protection against photo-bleaching is improved, but the display quality may be compromised

Engineering Contradiction:
Improveprotection against photo-bleachingVSAvoiddisplay quality
Core Design Contradiction:
ReliabilityVSIllumination intensity

Solution Approach 1:

The radiation filter is designed with wavelength-selective properties that apply different transmission characteristics to different parts of the electromagnetic spectrum. It provides high blocking in the UV and high-energy visible ranges where photo-bleaching occurs, while maintaining high transmission in the visible range required for display quality. This local differentiation of transmission properties allows simultaneous achievement of protection and display performance.

Inventive Principle:
Principle #3Local quality

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 radiation filter effectively reduces radiation-induced deterioration of the fluids, thereby enhancing the lifetime of the electrowetting display device without compromising display effects.

Implementation Method 1

a dye for example, which in some known devices is susceptible to photo-bleaching

Methodology Applied
Scientific EffectPhoto-bleaching: Photodissociation

Implementation Method 2

a radiation filter configured to filter at least some of the radiation of the at least one predetermined wavelength

Methodology Applied
Scientific EffectRadiation filtering: Absorption (EM radiation)

Data Source

PatentEP3201675B1Electrowetting display device comprising a radiation filter
Publication Date: 2020.11.04 AMAZON TECH INC
  • EP3201675B1 patent drawingFigure 1~2
  • EP3201675B1 patent drawingFigure 3
  • EP3201675B1 patent drawingFigure 4

AI summary

An electrowetting display device includes a picture element. There is a surface for receiving incident radiation for entering picture element. A first fluid and a second fluid immiscible with the first fluid are usable to provide a display effect. At least one of the first fluid or the second fluid are susceptible to deterioration by exposure to radiation of at least one predetermined wavelength. A support plate is located between the surface and at least one of the first or second fluids. The support plate includes a layer including a radiation filter configured to filter radiation of the at least one predetermined wavelength.