Vehicle Interior Light Box Layout for Compact Beam Homogenization

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional optical systems for vehicle interior lighting face challenges in space constraints and light beam homogenization due to the use of traditional light guides, which often require significant space and can disrupt light refraction.

Innovation Solution

The optical system employs a light box with an internal volume filled with air, featuring a series arrangement of light sources and a screen stacked along a longitudinal axis, using reflective walls and elliptical or parabolic cavity profiles to guide and concentrate light beams without additional homogenization components, allowing for dynamic and multi-colored lighting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a conventional light guide is used for homogenization, then light beam homogenization is achieved, but the system requires significant space and causes light refraction disturbances

Engineering Contradiction:
Improvelight beam homogenizationVSAvoidspace requirement
Core Design Contradiction:
Illumination intensityVSVolume of moving object

Solution Approach 1:

The patent extracts the homogenization function from the traditional light guide structure by using a light box filled with air instead of solid PMMA material. This removes the refraction problem while maintaining homogenization through reflective walls and multiple light sources, reducing the volume required for the system.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the physical state of the medium from solid (PMMA) to gas (air) in the light box, eliminating refraction. It also changes the homogenization mechanism from refraction-based to reflection-based, using reflective walls and multiple light sources to achieve uniform illumination without the space and refraction issues of conventional light guides.

Inventive Principle:
Principle #35Parameter changes

2Illumination intensity

If a conventional light guide is used, then light transmission is achieved, but refraction of the light beam occurs which disturbs homogenization

Engineering Contradiction:
Improvelight beam transmissionVSAvoidlight beam homogenization stability
Core Design Contradiction:
Illumination intensityVSStability of the object's composition

Solution Approach 1:

The patent removes the refraction-causing PMMA material from the light transmission path by using an air-filled light box. Light sources are positioned outside the light box, and light is transmitted through reflection off the reflective walls, eliminating refraction disturbances and stabilizing homogenization.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces reflective walls as an intermediary between the light sources and the target area. These walls mediate the light transmission process by reflecting light in a controlled manner, replacing the refraction-based transmission of conventional light guides and achieving stable homogenization without refraction disturbances.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Volume of moving object

If the optical system is made compact for narrow locations, then space efficiency is improved, but light beam homogenization becomes difficult

Engineering Contradiction:
Improvesystem compactnessVSAvoidlight beam homogenization
Core Design Contradiction:
Volume of moving objectVSIllumination intensity

Solution Approach 1:

The patent segments the illumination function into multiple independent light sources positioned around the light box. This segmentation allows each light source to contribute to the overall homogenization, achieving uniform illumination in a compact configuration where a single large light guide would not fit.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from a planar light guide structure to a three-dimensional light box configuration with light sources positioned in space around it. This dimensional change enables compact integration while maintaining homogenization through spatial distribution of light sources and reflective walls, fitting narrow locations effectively.

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

4Illumination intensity

If additional optical parts are added for homogenization, then light beam homogenization is improved, but device complexity increases

Engineering Contradiction:
Improvelight beam homogenizationVSAvoidnumber of optical components
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The patent merges the homogenization function into the light box structure itself through the use of reflective walls and the spatial arrangement of multiple light sources. This integration eliminates the need for separate homogenization optical parts, reducing device complexity while achieving effective homogenization.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The light box structure serves multiple functions simultaneously: it contains the air-filled volume, provides reflective walls for light redirection, and supports the positioning of multiple light sources. This multi-functionality achieves homogenization without requiring additional specialized optical components, simplifying the overall device.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 enables efficient light beam homogenization and dynamic lighting effects within a compact form factor, suitable for narrow spaces, while eliminating the need for additional optical parts, thus providing flexible and space-efficient interior vehicle lighting.

Implementation Method 1

the light beam is emitted from the light source before being projected onto the screen, being deflected only by reflections, once or multiple times, against the walls of the light box

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 2

The cavity comprises an elliptical profile in a first plane perpendicular to the screen and passing through the light source associated with said cavity

Methodology Applied
Scientific EffectGeometric concentration: Geometry

Data Source

PatentEP3856570B1Optical system for interior lighting of a vehicle
Publication Date: 2024.02.14 VALEO VISION SA
  • EP3856570B1 patent drawingFigure 1
  • EP3856570B1 patent drawingFigure 2
  • EP3856570B1 patent drawingFigure 3

AI summary

The invention concerns an optical system (1, 2) for the interior lighting of a motor vehicle (100) - the optical system comprising a screen (6) and a plurality of light sources (32) arranged in series, the plurality of light sources being designed to project a light beam onto the screen, the optical system (1, 2) comprising a light box (4) between the plurality of light sources and the screen, the light box comprising a plurality of recesses (8), each light source (32) being associated with a recess (8) in the light box (4), each light source being capable of being activated separately. The invention also concerns a motor vehicle (100) comprising an interior lighting device (115) comprising such an optical system (1, 2). Said invention applies to motor vehicles.