Polarized Windscreen HUD Cover for Reflection Suppression

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Solution Overview

Problem

Existing head-up display devices in motor vehicles face challenges in reducing structural height while effectively suppressing ambient light reflections, particularly when combined with windscreen base display devices, due to limited installation space and the need for mirror banks that can obstruct the view.

Innovation Solution

Employing a transparent cover with a first polarization filter that transmits light of a first polarization direction and reflects light of a second polarization direction, combined with a windscreen base region having a second polarization filter oriented 90° to the first, allowing ambient light to be reflected away and enabling simultaneous use as a mirror bank and display surface without obstructing the view.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a reflective curved cover plate with light-absorbing surface is used to suppress ambient light reflections, then driver dazzling is prevented, but the structural height of the head-up display device increases to 5-10 cm

Engineering Contradiction:

Improveambient light reflectionVSAvoidstructural height

Core Design Contradiction:

Object-affected harmful factorsVSLength of stationary object

Solution Approach 1:

The patent changes the optical parameters of the cover plate by integrating a polarization filter that selectively transmits and reflects light based on polarization direction. This allows the cover plate to suppress ambient light reflections through polarization-based reflection rather than through curvature and distance, reducing the need for a tall light-absorbing surface structure.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent combines the cover plate with a polarization filter to create a composite optical component. This composite structure integrates the protective cover function with the ambient light suppression function in a single element, eliminating the need for a separate tall light-absorbing surface and reducing overall structural height.

Inventive Principle:

Principle #40Composite materials

2Adaptability or versatility

If a windscreen base display device is combined with head-up display, then display functionality is enhanced, but the mirror bank obstructs the view of the windscreen base display region

Engineering Contradiction:

Improvedisplay functionalityVSAvoidview obstruction

Core Design Contradiction:

Adaptability or versatilityVSLoss of information

Solution Approach 1:

The patent makes the cover plate multi-functional by integrating a polarization filter that serves both as part of the head-up display optical system and as a component that manages light for the windscreen base display region. The cover plate with polarization filter acts as both a protective cover and an active optical element that suppresses reflections while allowing the windscreen base display to be viewed.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The polarization filter in the cover plate acts as an intermediary that mediates between the head-up display projection light and the ambient light. It selectively transmits projection light while reflecting ambient light, and this same polarization-based mechanism allows the windscreen base display region to be visible without obstruction from the mirror bank.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 reduces the structural height of the head-up display device and prevents driver dazzling by ambient light reflections, while allowing both head-up and windscreen base display information to be perceived without interference.

Implementation Method 1

the first polarization filter transmits light of a first polarization direction and reflects light of a second polarization direction

Methodology Applied

Scientific EffectPolarization: Polarisation

Implementation Method 2

The reflected ambient light is only reflected to a minor extent on the light-absorbing surface, so that interfering reflections of ambient light or lights in a display region on the windscreen can be essentially avoided

Methodology Applied

Scientific EffectReflection: Reflection

Data Source

PatentUS12429642B2Arrangement for reflection suppression in a windscreen display system, and windscreen display system

Publication Date: 2025.09.30 BAYERISCHE MOTOREN WERKE AG

AI summary

A windscreen display system for a motor vehicle includes a head-up display device. The head-up display device includes a projection device for emitting a projection light beam with a first item of image information towards a first display region of a windscreen so that it is reflected there and can be perceived in an eye region, and a transparent covering for protecting the projection device, the covering having a cover pane and a first polarization filter, the first polarization filter transmitting light with a first polarization direction and fully reflecting light with a second polarization direction.