Vehicular Roof Light Guide Member Floating Illumination

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Solution Overview

Problem

Existing vehicular interior lighting systems fail to create a novel and visually appealing lighting effect that gives a sense of floating light, as passengers can typically see the light sources and the lighting lacks a harmonious integration with vehicle designs.

Innovation Solution

A vehicular interior lighting device and roof module with a light guide member that protrudes from the housing, featuring a diffusion portion and reflecting surfaces, which directs light from multiple light sources to create a floating effect, while the light sources are concealed from view, and touch sensors for easy operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If the light source is positioned behind the illumination lens for straightforward lighting, then the lighting function is simple and reliable, but passengers can view the light source directly which reduces aesthetic appeal and novelty

Engineering Contradiction:
Improvelighting functionVSAvoidaesthetic appeal
Core Design Contradiction:
Illumination intensityVSShape

Solution Approach 1:

The patent introduces a light guide member as an intermediary between the light source and the illumination area. The light guide member has a light source contact portion that receives light from the LED and a light emission portion that displays the light to passengers. This intermediary structure allows the light source to be positioned away from direct view while still achieving effective illumination, resolving the contradiction between functional simplicity and aesthetic appeal.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The light guide member extends in the vehicle width direction, creating a horizontal dimension for light transmission. By positioning the light source at one end and having the light emission portion extend along the vehicle width, the patent transforms the traditional vertical light path into a horizontal one, allowing the light source to be concealed while the light emission occurs along the extended structure.

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

2Adaptability or versatility

If multiple light sources are added to create complex lighting patterns, then lighting versatility and novelty are improved, but device complexity and structural integration become more difficult

Engineering Contradiction:
Improvelighting patternsVSAvoidstructural integration
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The light guide member serves multiple functions: it guides light from the LED, structures the light emission pattern, provides mechanical support, and integrates with the vehicle's ceiling structure. By making the light guide member a multi-functional component, the patent achieves versatile lighting patterns without proportionally increasing device complexity, as the same structure performs multiple roles.

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

Solution Approach 2:

The patent combines the light guide function, structural support function, and light emission function into a single integrated light guide member. Rather than using separate components for light guidance, support, and emission, these functions are merged into one component that extends along the vehicle width, simplifying the overall structure while enabling complex lighting patterns.

Inventive Principle:
Principle #5Merging (Combining)

3Shape

If the light guide member extends far in the vehicle width direction to create floating light effects, then aesthetic appeal and novelty are improved, but the risk of light leakage and glare increases

Engineering Contradiction:
Improvefloating light effectVSAvoidlight leakage and glare
Core Design Contradiction:
ShapeVSObject-affected harmful factors

Solution Approach 1:

The light guide member has different optical properties at different locations: the light source contact portion has high light absorption to prevent backward leakage, while the light emission portion has optimized transparency for controlled light display. This local differentiation of optical quality allows the extended structure to create floating light effects while minimizing glare and unwanted light leakage at specific critical locations.

Inventive Principle:
Principle #3Local quality

4Shape

If the light source is concealed to create floating light illusion, then aesthetic appeal and novelty are improved, but light source maintenance and replacement become more difficult

Engineering Contradiction:
Improvefloating light illusionVSAvoidlight source maintenance
Core Design Contradiction:
ShapeVSEase of repair

Solution Approach 1:

The lighting system is segmented into a permanently installed light guide member and a replaceable light source unit. The light source contact portion of the light guide member is designed to accept and accommodate the LED module, which can be independently removed and replaced. This segmentation allows the light source to be concealed for aesthetic purposes while maintaining ease of maintenance through modular replacement capability.

Inventive Principle:
Principle #1Segmentation

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 system achieves a novel lighting effect that gives passengers a sense of floating light, improving the aesthetic and usability of the lighting system, while ensuring seamless integration with vehicle designs and reducing glare.

Implementation Method 1

a light guide member (5) having a protruding portion (52) protruding toward a direction along an inside surface (101a) from a gap (G1) between the main body portion (7) and the cover portion (8) and guiding light emitted from the first light source (4) and the second light source (9) to a cabin

Methodology Applied
Scientific EffectLight transmission: Light

Implementation Method 2

a diffusion portion (53) formed on a surface of the protruding portion (52) facing downward and diffusing light

Methodology Applied
Scientific EffectLight diffusion: Diffusion

Implementation Method 3

a reflecting portion (55) reflecting light emitted from the second light source (9) and incident on the light guide member (5) via the condensing lens (15) toward a part of the diffusion portion (53)

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 4

a condensing lens (15) disposed between the second light source (9) and the light guide member (5)

Methodology Applied
Scientific EffectLight condensation: Lens

Data Source

PatentEP3613635B1Vehicular interior lighting device and roof module
Publication Date: 2022.03.23 YAZAKI CORP
  • EP3613635B1 patent drawingFigure 1
  • EP3613635B1 patent drawingFigure 2
  • EP3613635B1 patent drawingFigure 3

AI summary

A vehicular interior lighting device (2) includes a main body portion (7) fixed to a roof, a first and second light sources (4, 9) accommodated in the main body portion, a light shielding cover portion (8) covering the first and second light sources from below, a light guide member (5) having a protruding portion (52) protruding along the inside surface from a gap between the main body portion and the cover portion, and a condensing lens (15) disposed between the second light source and the light guide member. The light guide member has a diffusion portion (53) on a surface of the protruding portion facing downward and a reflecting portion (55) reflecting light from the second light source toward a part of the diffusion portion. The diffusion portion emits light in whole by light from the first light source and partially emits light by light from the second light source.