HUD Windshield Coating Structure for Low-Reflectance Ghosting Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional automotive heads-up displays (HUDs) suffer from 'ghosting' due to multiple reflections from the windshield, and additional coatings for solar control and antenna functionality further complicate the issue by introducing more reflections.
Innovation Solution
A coated article with a substrate and a functional coating comprising multiple dielectric and metallic layers, specifically designed to minimize reflections and improve solar performance, is applied to the windshield.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional windshield with multiple glass plies is used, then the HUD system forms multiple reflected images (ghosting), but the windshield provides basic structural support and optical clarity
Solution Approach 1:
A functional coating layer is introduced as an intermediary between the glass plies and the external environment. This coating layer serves as a mediator that controls light reflection and transmission, eliminating ghosting while maintaining the structural integrity of the multi-ply windshield construction.
Solution Approach 2:
The windshield incorporates a composite structure consisting of multiple glass plies bonded with interlayer material, with an additional functional coating layer applied to one or more surfaces. This composite material approach allows simultaneous achievement of structural strength, optical clarity, and ghosting elimination.
2Reliability
If a wedge-shaped vinyl layer is added between glass plies to align reflected images, then ghosting is reduced, but the cost and manufacturing complexity increase
Solution Approach 1:
The complex wedge-shaped vinyl layer is replaced by a simpler functional coating applied directly to the glass surface. This extraction of the complexity from the internal windshield structure simplifies manufacturing while achieving the same ghosting elimination effect through optical property control.
Solution Approach 2:
The mechanical wedge-shaped structure is replaced by a thin-film coating that uses optical interference and reflection control to achieve image alignment. This substitution transitions from a mechanical geometry-based solution to an optical property-based solution, reducing manufacturing complexity.
3Loss of energy
If additional functional coatings are applied for solar control and antenna functionality, then solar performance and energy efficiency improve, but more reflections are introduced creating additional ghost images
Solution Approach 1:
The functional coating is designed to perform multiple functions simultaneously: solar control (reducing heat gain), antenna functionality (RF transparency), and optical control (ghosting elimination). This multi-functional coating eliminates the need for separate coatings, reducing the total number of interfaces and reflections.
Solution Approach 2:
Multiple functional requirements (solar control, antenna functionality, optical clarity) are merged into a single integrated coating layer. This consolidation reduces the number of separate coating interfaces, thereby minimizing total reflections while achieving all desired functions.
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 effectively reduces or eliminates ghosting in HUD systems while enhancing solar performance and energy efficiency.
Implementation Method 1
A coated article with a substrate and a functional coating comprising multiple dielectric and metallic layers, specifically designed to minimize reflections
Implementation Method 2
A coated article with a substrate and a functional coating comprising multiple dielectric and metallic layers, specifically designed to minimize reflections and improve solar performance
Data Source
AI summary
A coated article comprising includes a substrate comprising a first surface and second surface opposite the first surface and a coating applied over the surface. The coating includes: a first dielectric layer over at least a portion of the surface; a first metallic layer over at least a portion of the first dielectric layer; a second dielectric layer over at least a portion of the first metallic layer; a second metallic layer over at least a portion of the second dielectric layer; a third dielectric layer over at least a portion of the second metallic layer; a third metallic layer over at least a portion of the third dielectric layer; a fourth dielectric layer over at least a portion of the third metallic layer; an optional fourth metallic layer over at least a portion of the fourth dielectric layer; an optional fifth dielectric layer over at least a portion of the fourth metallic layer; and an outermost protective layer formed over at least a portion of the fourth or fifth dielectric layer. The coated article has a total combined thickness of the metallic layers is at least 10 nanometers, and no more than 60 nanometers.