Electrowetting Display Shaped Color Filter Luminance

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Solution Overview

Problem

Electrowetting display devices often have lower than desired luminance due to limitations in controlling color gamut and luminance through pixel color filters.

Innovation Solution

Incorporating a color filter layer with a combination of a transmissive region and a color filter, where the transmissive region is designed to transmit a higher percentage of light than the color filter, allowing for greater control over luminance and saturation by adjusting the fluid configurations in response to applied voltages.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If pixel color filters are designed with appropriate hue and saturation parameters to control color gamut, then color accuracy is improved, but luminance decreases

Engineering Contradiction:
Improvecolor gamut controlVSAvoidluminance
Core Design Contradiction:
Measurement precisionVSIllumination intensity

Solution Approach 1:

The color filter layer is divided into multiple independent color filter regions (red, green, blue) with different optical properties. Each region can be independently optimized for its specific wavelength range, allowing selective light transmission that maintains color accuracy while improving overall luminance by not blocking all non-target wavelengths uniformly

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the color filter layer are assigned different hue and saturation characteristics tailored to their specific function. The red, green, and blue regions have locally optimized parameters that collectively improve color gamut control while their combined transmissive properties enhance luminance compared to a uniform filter design

Inventive Principle:
Principle #3Local quality

2Measurement precision

If color filter thickness is increased to improve saturation, then color intensity is improved, but light transmission and luminance decrease

Engineering Contradiction:
ImprovesaturationVSAvoidluminance
Core Design Contradiction:
Measurement precisionVSIllumination intensity

Solution Approach 1:

The patent optimizes the thickness parameter of the color filter layer to achieve the desired balance between saturation and luminance. By carefully selecting and adjusting the thickness value, the filter provides sufficient color intensity while maintaining adequate light transmission, resolving the trade-off between these two parameters

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

This configuration enhances luminance and provides more design freedom for achieving desired color gamuts, such as sRGB or AdobeRGB, while reducing cross-talk between adjacent display elements, thereby improving the overall display effect.

Implementation Method 1

the transmissive region is designed to transmit a higher percentage of light than the color filter

Methodology Applied
Scientific EffectLight transmission and filtering: Filter (optical)

Implementation Method 2

electrowetting display device with a color filter layer

Methodology Applied
Scientific EffectElectrowetting: Electrowetting

Data Source

PatentEP3237952B1Electrowetting display device with shaped colour filter
Publication Date: 2020.02.12 AMAZON TECH INC
  • EP3237952B1 patent drawingFigure 1
  • EP3237952B1 patent drawingFigure 2A
  • EP3237952B1 patent drawingFigure 2B~2D

AI summary

An electrowetting display device comprising: a first fluid adjoining a surface of a support plate; a second fluid; a colour filter for outputting light with a predetermined hue; a transmissive region configured to transmit light of at least one wavelength filtered by the colour filter; and an electrode for use in applying a voltage to control a configuration of the first and second fluids. In a first configuration the first fluid adjoins a first extent of the surface and overlaps a first extent of the colour filter and a first extent of the transmissive region. In a second configuration the first fluid adjoins a second extent of the surface and overlaps a second extent of the colour filter and a second extent of the transmissive region.