Nano-Coated HUD Windshield for Ghost-Free Projection and Insulation

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Solution Overview

Problem

Existing head-up display (HUD) technologies in automobiles require expensive, specialized polyvinyl butyral coatings that are difficult to apply and provide poor thermal insulation and thermal comfort, leading to high material and technological costs, limited applicability across vehicle models, and inadequate ghosting suppression.

Innovation Solution

A vehicle window glass with a transparent nano coating that reflects P-polarized light, ensuring high visible light transmittance and low total solar energy transmittance, combined with an electric heating function, to achieve an HUD image without ghosting and enhance thermal insulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a wedge-shaped PVB coating is used to achieve HUD image without ghosting, then ghosting is suppressed, but material cost increases 7 to 10 times and technological difficulty is high

Engineering Contradiction:
ImproveghostingVSAvoidmaterial cost and technological difficulty
Core Design Contradiction:
Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The patent changes the optical parameters of the PVB coating by controlling its thickness (3mm to 8mm) and using white light illumination with specific spectral characteristics. This transforms the coating's interaction with light to suppress ghosting through interference effects rather than requiring expensive specialized formulations

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent makes the HUD window universally applicable across different vehicle models by using standard PVB materials and adjustable thickness parameters, eliminating the need for model-specific custom coatings while achieving ghosting suppression

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

2Object-affected harmful factors

If a specialized PVB coating is used for HUD function, then ghosting is reduced, but thermal insulation effect is poor and thermal comfort requirements are not met

Engineering Contradiction:
ImproveghostingVSAvoidthermal insulation effect
Core Design Contradiction:
Object-affected harmful factorsVSTemperature

Solution Approach 1:

The patent optimizes the PVB coating thickness parameter (3mm to 8mm) to simultaneously achieve two functions: suppressing ghosting through optical interference and providing adequate thermal insulation. This parameter optimization allows one material to fulfill multiple functions without contradiction

Inventive Principle:
Principle #35Parameter changes

3Object-affected harmful factors

If different PVB coatings are designed for different vehicle models, then ghosting suppression is optimized for each model, but applicability is poor and manufacturing complexity increases

Engineering Contradiction:
ImproveghostingVSAvoidapplicability across vehicle models
Core Design Contradiction:
Object-affected harmful factorsVSAdaptability or versatility

Solution Approach 1:

The patent creates a universal HUD window solution that can be applied to different vehicle models by using standard PVB materials with adjustable thickness (3mm to 8mm). The system achieves model-independent ghosting suppression through parameter optimization rather than custom design, significantly improving versatility

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

Solution Approach 2:

The patent uses thickness as a adjustable parameter (3mm to 8mm) that can be optimized for different applications without changing the fundamental material or design, enabling universal applicability across various vehicle models while maintaining ghosting suppression performance

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 a cost-effective, universally applicable HUD window with improved thermal comfort, safety, and defrosting capabilities while suppressing ghosting and ensuring high-quality image projection.

Implementation Method 1

The window glass can reflect P-polarized light, thereby achieving an HUD image without ghosting

Methodology Applied
Scientific EffectP-polarized light reflection: Reflection

Implementation Method 2

the window glass has a visible light transmittance greater than or equal to 70% and a total solar energy transmittance less than or equal to 50%, thereby not only ensuring the safety requirements of driving, but also achieving a good thermal insulation effect

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 3

even incorporates an electric heating function, thereby meeting the safety driving requirements of defrosting and defogging

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP4421552B1Head-up display window, and vehicle
Publication Date: 2025.12.31 FUYAO GLASS IND GROUP CO LTD
  • EP4421552B1 patent drawingFigure 1~2
  • EP4421552B1 patent drawingFigure 3

AI summary

A head-up display (HUD) window includes a window glass and a projector (1). The window glass includes a glass layer (2) and a transparent nano coating (3). The transparent nano coating (3) is disposed on the glass layer (2). The projector (1) is configured to generate and project a projection light ray onto the window glass to form a projection image. A proportion of P-polarized light in the projection light ray is greater than or equal to 70%. The transparent nano coating (3) is capable of reflecting at least part of the P-polarized light incident. The window glass has a reflectivity for the P-polarized light greater than or equal to 5%. The window glass has a visible light transmittance greater than or equal to 70%. The window glass has a total solar energy transmittance less than or equal to 50%. The window glass in the disclosure has a good thermal insulation effect, thereby satisfying the usage requirements of thermal comfort.