Infrared-Permeable Plastic Components in Motor Vehicle Lighting

Solution Overview

Problem

Conventional motor vehicle lighting devices suffer from aesthetic and functional impairments due to solar radiation, particularly high-energy infrared radiation, which can cause heating and damage to dark-colored plastic components when focused by light-focusing means such as converging lenses or curved cover plates.

Innovation Solution

Incorporating infrared-permeable plastic components, like those made from materials like 'Makrolon' or 'Apec', which allow over 50% transmission of infrared radiation, especially in the near-infrared range, to prevent absorption and heating of dark-colored components, while maintaining their dark appearance and functionality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If dark-colored plastic components are used in the lighting device, then aesthetic appearance and light absorption are improved, but heating and damage from focused solar radiation occur

Engineering Contradiction:

Improveaesthetic appearanceVSAvoidcomponent heating

Core Design Contradiction:

ShapeVSTemperature

Solution Approach 1:

The patent applies local quality by making only the components located in the focal region of the converging lens infrared-permeable, while other components can remain with conventional dark coloring. This selective application allows aesthetic dark appearance to be maintained where it serves its purpose while preventing heating only where solar radiation focuses.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent uses composite materials by combining infrared-permeable plastic material with dark coloring properties in the affected components. This composite approach allows the material to simultaneously achieve aesthetic dark appearance and functional infrared transmission, resolving the contradiction between appearance and heat resistance.

Inventive Principle:

Principle #40Composite materials

2Shape

If conventional dark-colored plastic components are used, then aesthetic appearance is maintained, but surface changes and damage occur due to infrared radiation absorption

Engineering Contradiction:

Improveaesthetic appearanceVSAvoidcomponent integrity

Core Design Contradiction:

ShapeVSReliability

Solution Approach 1:

The patent applies local quality by making only the components located in the focal region of the converging lens infrared-permeable, while other components can remain with conventional dark coloring. This selective application allows aesthetic dark appearance to be maintained where it serves its purpose while preventing heating only where solar radiation focuses.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent uses composite materials by combining infrared-permeable plastic material with dark coloring properties in the affected components. This composite approach allows the material to simultaneously achieve aesthetic dark appearance and functional infrared transmission, resolving the contradiction between appearance and heat resistance.

Inventive Principle:

Principle #40Composite materials

3Temperature

If infrared-permeable plastic material is used, then heating and damage from infrared radiation are prevented, but material selection and manufacturing complexity increase

Engineering Contradiction:

Improvecomponent heatingVSAvoidmaterial selection

Core Design Contradiction:

TemperatureVSEase of manufacture

Solution Approach 1:

The patent applies local quality by making only the components located in the focal region of the converging lens infrared-permeable, while other components can remain with conventional dark coloring. This selective application allows aesthetic dark appearance to be maintained where it serves its purpose while preventing heating only where solar radiation focuses.

Inventive Principle:

Principle #3Local quality

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

Prevents surface changes, deformation, and damage to components by allowing infrared radiation to pass through without heating, ensuring the lighting device's appearance remains unchanged and functional, with the option to dissipate heat through cooling elements or air circulation.

Implementation Method 1

dunkle gefärbte Bauteile (22) aus einem infrarotdurchlässigen Material gefertigt sind, so dass eine Infrarotstrahlung, die von außen in das Gehäuse (17) einfällt und durch die Lichtbündelungsmittel (10; 15; 18) gebündelt wurde, diese Bauteile (22) durchdringen kann

Methodology Applied

Scientific EffectInfrared radiation transmission: Infrared Radiation

Implementation Method 2

Conventional motor vehicle lighting devices suffer from aesthetic and functional impairments due to solar radiation, particularly high-energy infrared radiation, which can cause heating and damage to dark-colored plastic components when focused by light-focusing means

Methodology Applied

Scientific EffectAbsorption (EM radiation): Absorption (EM radiation)

Implementation Method 3

Lichtbündelungsmittel (10; 15; 18), insbesondere wenn diese als Sammellinse ausgeführt ist

Methodology Applied

Scientific EffectLight focusing: Focusing

Implementation Method 4

projection optics, especially if this is designed as a converging lens

Methodology Applied

Scientific EffectConverging lens: Lens

Data Source

PatentEP2672170B1Illumination device of a motor vehicle

Publication Date: 2022.02.09 MARELLI GERMANY GMBH

Figure 1~2

AI summary

The illumination device (5) comprises light focusing units such as reflector (10), cover plate (15) and condenser lens (18), and dark colored components (22) made of plastic, and infrared transmitting material. The dark-colored components consist of a thermoplastic material with color pigments. The 6.dark-colored components have infrared transmittance of 90%. The thermoplastic material is formed of polycarbonate.