Fluorescent Electrowetting Windshield Display for Sunlight Visibility

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Solution Overview

Problem

Existing windshield displays, even those using fluorescent films and transparent displays, are not bright enough to be effective in bright sunlight conditions, making it difficult for vehicle operators to view information without diverting their attention from the forward field of view.

Innovation Solution

A windshield assembly incorporating a fluorescent electrowetting cell that can switch between a fluorescent and transparent state, combined with an opaque electrowetting cell that can switch between opaque and clear states, allowing for image contrast and improved visibility against bright backgrounds by surrounding the fluorescent image with a contrasting border.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If fluorescent films and transparent displays are used in the windshield, then the display can be positioned in the field of view, but the brightness is insufficient in bright sunlight

Engineering Contradiction:
Improvedisplay brightnessVSAvoidvisibility in bright sunlight
Core Design Contradiction:
Illumination intensityVSReliability

Solution Approach 1:

The patent applies fluorescent materials that change their optical properties by absorbing ultraviolet light and emitting visible light at different wavelengths. The fluorescent layer transforms UV illumination into bright visible display elements, dramatically increasing display brightness and visibility in bright sunlight conditions while maintaining the ability to be viewed within the driver's field of view.

Inventive Principle:
Principle #32Color changes

2Stability of the object's composition

If a transparent display is used, then the windshield remains visible, but the image contrast is insufficient against bright backgrounds

Engineering Contradiction:
Improvewindshield transparencyVSAvoidimage contrast
Core Design Contradiction:
Stability of the object's compositionVSLoss of information

Solution Approach 1:

The patent implements local quality by applying fluorescent material only in specific patterns or regions where information needs to be displayed, while leaving other portions of the windshield transparent. This allows the display areas to have high contrast through fluorescent emission, while the rest of the windshield maintains its transparent quality for unobstructed viewing.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent uses composite material structures combining fluorescent materials with transparent substrates or encapsulants. This composite approach allows the display regions to exhibit fluorescent properties for high contrast, while the overall structure maintains transparency when the fluorescent material is not activated or in non-display areas.

Inventive Principle:
Principle #40Composite materials

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 enhances visibility of displayed information in bright sunlight by ensuring the image stands out against bright backgrounds, maintaining transparency for clear viewing and providing a contrasting edge to make the image more readable.

Implementation Method 1

The fluorescent electrowetting cell is operable to a fluorescent state where the fluorescent electrowetting cell fluoresces when illuminated with suitable light

Methodology Applied
Scientific EffectFluorescence: Fluorescence

Implementation Method 2

A windshield assembly incorporating a fluorescent electrowetting cell that can switch between a fluorescent and transparent state, combined with an opaque electrowetting cell

Methodology Applied
Scientific EffectElectrowetting: Electrowetting

Data Source

PatentEP2602138B1Windshield with fluorescent electrowetting display
Publication Date: 2016.05.18 DELPHI TECHNOLOGIES INC
  • EP2602138B1 patent drawingFigure 1
  • EP2602138B1 patent drawingFigure 2
  • EP2602138B1 patent drawingFigure 3

AI summary

A windshield assembly (10) that includes a fluorescent electrowetting cell (24) and an opaque electrowetting cell (28) overlying a windshield (22) and configured so the opaque electrowetting cell (28) cooperates with the fluorescent electrowetting cell (24) to contrast an image (36) displayed by the fluorescent electrowetting cell (24) with respect to a field of view (16) beyond the windshield assembly (10). The ability to contrast the image (36) makes the image (36) easier to see when bright sunlight is present.