Vehicle Light Unit With Conductive Diffuser for Homogeneous LED Output

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Solution Overview

Problem

Existing lighting and signaling devices for motor vehicles face challenges in achieving homogeneous luminous patterns using pixelated elementary light sources, as they often result in a set of light points that appear close together, and current solutions like OLEDs are costly and less reliable than conventional LEDs.

Innovation Solution

A light assembly using conventional LEDs with a support structure and optically transparent, electrically conductive covering material to create a homogeneous illuminating surface by diffusing light from each source, ensuring electrical contact and mechanical retention, while maintaining a low cost and high light output.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If conventional LEDs are arranged in a pixelated pattern with minimal spacing, then light intensity and cost-effectiveness are improved, but luminous homogeneity deteriorates (appears as discrete light points)

Engineering Contradiction:
Improvelight intensityVSAvoidluminous homogeneity
Core Design Contradiction:
Illumination intensityVSManufacturing precision

Solution Approach 1:

A transparent covering layer is introduced as an intermediary element between the discrete LEDs and the observer. This layer diffuses the light from individual LEDs, merging the discrete light points into a continuous homogeneous luminous surface while preserving the high light intensity output of conventional LEDs.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The transparent covering layer modifies the optical appearance by diffusing light, transforming the visual perception from discrete points to a continuous surface. This optical transformation achieves luminous homogeneity without changing the physical arrangement or intensity of the underlying LEDs.

Inventive Principle:
Principle #32Color changes

2Manufacturing precision

If OLEDs are used to create emissive surfaces, then luminous homogeneity is improved, but cost, reliability, and light intensity performance worsen

Engineering Contradiction:
Improveluminous homogeneityVSAvoidreliability
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

Instead of using OLEDs to directly emit light, the invention uses conventional LEDs as light sources and creates a visual copy of a continuous emissive surface through the diffusing covering layer. This approach achieves the appearance of OLED homogeneity while maintaining the reliability and cost advantages of conventional LEDs.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The transparent covering layer acts as a mediator that translates the discrete output of conventional LEDs into a continuous luminous appearance, eliminating the need to switch to less reliable OLED technology while still achieving the desired homogeneous visual effect.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Area of stationary object

If elementary light sources are placed close together, then device size is reduced, but the perception of discrete light points increases

Engineering Contradiction:
Improvedevice sizeVSAvoidluminous homogeneity
Core Design Contradiction:
Area of stationary objectVSManufacturing precision

Solution Approach 1:

The transparent covering layer serves as a visual mediator that obscures the discrete nature of closely-spaced LEDs. By diffusing light across the covering layer, it creates a continuous luminous appearance even when LEDs are positioned at minimal spacing, thus achieving compact device size without sacrificing perceived homogeneity.

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

The solution produces a perceived homogeneous illuminating surface with reliable and optically efficient conventional LEDs, reducing production costs and enhancing aesthetic appeal while maintaining high light intensity and long lifespan.

Implementation Method 1

optically transparent and electrically conductive covering material to create a homogeneous illuminating surface by diffusing light from each source

Methodology Applied
Scientific EffectLight diffusion: Scattering

Data Source

PatentEP4078674B1Light unit for a lighting and/or signalling device for a motor vehicle
Publication Date: 2024.05.15 VALEO VISION SA
  • EP4078674B1 patent drawingFigure 1
  • EP4078674B1 patent drawingFigure 2
  • EP4078674B1 patent drawingFigure 3

AI summary

The invention relates to a light unit (100) for a lighting and/or signalling device of a motor vehicle, comprising a plurality of basic light sources (1a, … 1i, … 1n) arranged on a support (200). In the light unit (100) according to the invention, each basic light source (1a, … 1i, … 1n) is a light-emitting diode which is electrically connected, on the one hand, to a first conductive layer (30) of the support (200) and, on the other hand, to a second conductive layer (31) of the support (200), the first conductive layer (30) and the second conductive layer (31) being arranged on either side of a thickness (20) of the support (200). In the light unit (100) according to the invention, each light-emitting diode (1a, … 1i, … 1n) is placed in a receiving aperture (5a, … 5i, … 5n) which is arranged in the support (200), the receiving aperture (5a, … 5i, … 5n) extending through the first conductive layer (30) and through a thickness (20) of the support (200), respectively, as far as the second conductive layer (31), each light-emitting diode (1a, … 1i, … 1n) being partially encapsulated in a covering material (80, 80') which is optically transparent and electrically conductive.