Liquid Crystal Display Thermal Management with Longitudinal Heat Absorption

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Solution Overview

Problem

Liquid crystal screens in high-vehicle head displays experience thermal heating due to light absorption, which can reduce their lifespan and require frequent replacement, as existing cooling solutions are inadequate.

Innovation Solution

Incorporating a heat absorption device with longitudinal elements, such as metal wires, arranged alongside conductive tracks to minimize light obstruction and facilitate heat dissipation, and utilizing thermoelectric elements like the Peltier effect to actively cool the screen.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If the screen projects particularly bright images to improve visibility in ambient light, then illumination intensity is improved, but temperature increases causing overheating

Engineering Contradiction:
Improvebrightness of projected imageVSAvoidscreen temperature
Core Design Contradiction:
Illumination intensityVSTemperature

Solution Approach 1:

The patent converts the harmful heat generated by bright image projection into a beneficial cooling effect by using thermoelectric cooling elements (Peltier elements) that are activated by the same electrical current that drives the backlight, thereby converting waste heat into active cooling capacity

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

Solution Approach 2:

The patent introduces thermal management elements including heat-absorbing materials positioned between the backlight and liquid crystal layer, and heat-dissipating structures on the opposite side of the screen, acting as intermediaries to manage heat flow without interfering with the optical function

Inventive Principle:
Principle #24Intermediary (Mediator)

2Temperature

If longitudinal heat absorption elements are added to cool the screen, then temperature control is improved, but light transmission is obstructed

Engineering Contradiction:
Improvescreen temperatureVSAvoidlight transmission
Core Design Contradiction:
TemperatureVSIllumination intensity

Solution Approach 1:

The patent applies different properties to different regions: heat-absorbing longitudinal elements are placed specifically over conductive tracks where heat generation is highest, while other regions maintain optimal optical properties, thereby localizing the thermal management function to minimize impact on light transmission

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent addresses the two-dimensional conflict between heat absorption and light transmission by moving the heat management function to the longitudinal dimension (vertical placement of heat-absorbing elements), allowing simultaneous optimization of both optical and thermal properties in their respective dimensions

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Productivity

If the screen operates continuously to maintain functionality, then productivity is improved, but heat accumulation increases reducing lifespan

Engineering Contradiction:
Improvecontinuous operation capabilityVSAvoidscreen lifespan
Core Design Contradiction:
ProductivityVSDuration of action of stationary object

Solution Approach 1:

The patent implements continuous thermal management through thermoelectric cooling elements that operate continuously alongside the backlight, ensuring heat is actively removed throughout operation rather than allowing heat accumulation, thereby enabling sustained productivity without lifespan reduction

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The patent incorporates heat-absorbing materials and thermal management structures in advance within the screen construction, providing a buffer capacity to absorb and manage heat before it can accumulate to damaging levels, thereby protecting the screen during continuous operation

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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 cools the liquid crystal screen, reducing thermal stress and extending its lifespan by minimizing light obstruction and utilizing thermoelectric cooling to manage heat effectively.

Implementation Method 1

at least one longitudinal element is a power supply electrode for a thermoelectric cell (located, for example, within the screen). The Peltier effect is then used to cool the screen.

Methodology Applied
Scientific EffectPeltier effect: Peltier Effect

Implementation Method 2

a plurality of said longitudinal elements are connected to a plate at at least one of their ends. Such longitudinal elements can thus conduct the heat they absorb to the plate, where this heat can be more easily dissipated.

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3479167B1Liquid crystal display, image generating device including such a display and head-up display including such a device
Publication Date: 2021.12.01 VALEO COMFORT & DRIVING ASSISTANCE
  • EP3479167B1 patent drawingFigure 1~3
  • EP3479167B1 patent drawingFigure 4~7

AI summary

The invention relates to a liquid crystal display comprising a matrix of liquid crystal elements (17), transistors (18), each associated with one of said elements (17) and conductive tracks (19) for connecting to said transistors (18). A heat absorbing device comprises a plurality of longitudinal elements (30; 130, 135; 230, 235; 330, 335), each arranged at right angles with one of said conductive tracks (19). An image-generating device comprising such a display and a head-up display comprising such a device are also described.