High Thermal Conductivity Reflector for HUD Screen Cooling

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Solution Overview

Problem

Head-up displays for vehicles face issues with screen overheating due to backlighting, leading to reduced lifespan and potential damage, with existing solutions either compromising brightness or exposing the optics to dust and light leaks.

Innovation Solution

An image generation device with a reflector having high thermal conductivity, positioned between the light source and screen, that evacuates excess heat through thermal conduction to heat dissipation elements, while also serving as a housing for the screen and maintaining a sealed enclosure to prevent dust and light leaks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a temperature probe is used to control light source power, then screen temperature is regulated, but display brightness is reduced and device bulk increases

Engineering Contradiction:

Improvescreen temperatureVSAvoiddisplay brightness

Core Design Contradiction:

TemperatureVSIllumination intensity

Solution Approach 1:

The harmful heat is extracted from the optical path by introducing a dedicated heat reflection portion that directs thermal energy away from the screen. This separates the heat management function from the light transmission function, allowing the light source to operate at full power without overheating the screen.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

A heat reflection portion is introduced as an intermediary element between the light source and the screen. This intermediary redirects thermal energy through a specific path (via the diffuser plate and housing wall) while allowing visible light to pass through to illuminate the screen at full brightness.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Temperature

If the device is opened to evacuate heat, then heat dissipation is improved, but the device becomes exposed to dust and light leaks

Engineering Contradiction:

Improveheat dissipationVSAvoiddust exposure and light leaks

Core Design Contradiction:

TemperatureVSObject-affected harmful factors

Solution Approach 1:

The housing wall serves multiple functions: it provides structural enclosure to protect against dust, acts as a heat conduction path for thermal management, and works with the diffuser plate to redirect heat away from the screen. This multi-functionality eliminates the need to open the device for heat dissipation.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The housing wall, which would normally just be a structural element, is converted into an active heat dissipation component. By making it thermally conductive and integrating it with the heat reflection portion, it becomes a beneficial heat evacuation path that maintains device sealing.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Temperature

If the reflector has high thermal conductivity, then heat evacuation is improved, but manufacturing complexity may increase

Engineering Contradiction:

Improveheat evacuationVSAvoidreflector manufacturing

Core Design Contradiction:

TemperatureVSEase of manufacture

Solution Approach 1:

The heat reflection portion and diffuser plate are merged into a single integrated component. This combination simplifies manufacturing by reducing the number of separate parts while maintaining both the heat redirection function and the light diffusion function. The integrated design allows for easier production compared to assembling multiple separate thermal management components.

Inventive Principle:

Principle #5Merging (Combining)

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

Effectively cools the screen, prevents overheating, maintains desired brightness levels, and protects the optics from dust and light leaks, enhancing the overall image quality and durability of the head-up display.

Implementation Method 1

the reflector has a thermal conductivity greater than 1 W.m-1 so that the reflector is adapted to evacuate, by thermal conduction effect, excess heat from the image generating device

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

a reflector arranged between said source of light and said screen so that an internal face of said reflector at least partly reflects the light emitted by the light source

Methodology Applied

Scientific EffectLight reflection: Reflection

Implementation Method 3

an outer face of the reflector is provided with a plurality of heat dissipation fins

Methodology Applied

Scientific EffectThermal radiation: Thermal Radiation

Implementation Method 4

an outer face of the reflector is provided with a plurality of heat dissipation fins

Methodology Applied

Scientific EffectConvection: Convection

Data Source

PatentEP3491444B1Image generating device and associated head-up display

Publication Date: 2021.08.04 VALEO COMFORT & DRIVING ASSISTANCE

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AI summary

The invention relates to an image generating device (20) comprising: - at least one light source (23), - a screen (21) designed to be backlit by said light source, and - a reflector (25) arranged between said light source and screen such that an inner face (25A) of the reflector reflects at least some of the light emitted by the light source. The reflector (25) has a thermal conductivity greater than 1 W.m-1.K-1. The invention also relates to a head-up display comprising an image generating device of this type.