Vehicle Roof Light Guide Structure for Floating Interior Lighting

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Solution Overview

Problem

Existing vehicular interior lighting devices fail to create a novel and visually appealing lighting effect that gives a sense of floating light, as passengers can often see the light sources and the lighting lacks a luxurious and harmonious design with the vehicle's interior.

Innovation Solution

A vehicular interior lighting device with a light guide member that protrudes from the housing, featuring a diffusion portion, a first light guide portion, and a reflecting portion, which directs light emitted from the light sources to create a floating effect, while a touch sensor on the tip surface allows easy operation and minimizes glare, and a display device integrated with the lighting module to enhance visibility and design harmony.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the light source is placed behind the illumination lens, then the lighting structure is simple, but the passenger can view the light source which reduces the floating effect

Engineering Contradiction:
Improvelighting structureVSAvoidfloating effect
Core Design Contradiction:
Device complexityVSIllumination intensity

Solution Approach 1:

A light guide member is introduced as an intermediary component between the light source and the illumination lens. The light guide member receives light from the light source and guides it to the illumination lens, allowing the light source to be positioned behind the lens while preventing direct viewing of the light source by passengers, thus maintaining the floating effect while keeping the structure simple

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The light guide member extends in the vehicle width direction with protruding portions that guide light laterally. This dimensional extension allows the light path to be routed around the illumination lens rather than directly through it, preventing passengers from seeing the light source while maintaining lighting functionality

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

2Illumination intensity

If a light guide member protrudes from the housing, then the floating effect is enhanced, but the device complexity increases

Engineering Contradiction:
Improvefloating effectVSAvoidhousing structure
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The light guide member is integrated with the housing structure, where the housing serves dual purposes as both the protective enclosure and the mounting structure for the light guide member. The housing includes a light source accommodating portion that directly interfaces with the light guide member, merging multiple structural functions into a single component

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The housing structure is designed to perform multiple functions: it protects internal components, provides mounting surfaces for the light guide member and light source, and includes reflective surfaces to optimize light distribution. This multi-functionality reduces the need for additional separate components, offsetting the complexity introduced by the protruding light guide member

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

3Illumination intensity

If the light source is covered by the light shielding cover portion, then the floating effect is improved, but the manufacturing complexity increases

Engineering Contradiction:
Improvefloating effectVSAvoidassembly process
Core Design Contradiction:
Illumination intensityVSEase of manufacture

Solution Approach 1:

The housing is divided into separate segments: the main housing body and the light shielding cover portion. This segmentation allows each component to be manufactured independently using standard processes, then assembled together. The cover portion can be separately molded and attached to the housing, simplifying manufacturing while maintaining the floating effect by covering the light source

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 solution provides a novel lighting experience with a floating effect, improved visibility of the display device, and a harmonious integration with the vehicle's design, enhancing passenger comfort and aesthetic appeal.

Implementation Method 1

a light guide member having a protruding portion protruding toward a direction along the inside surface from a gap between the main body portion and the cover portion and guiding light emitted from the light source to a cabin

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Implementation Method 2

a reflecting portion reflecting light guided by the first light guide portion toward the diffusion portion

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 3

a diffusion portion. The light guide member has a first light guide portion guiding light emitted from the light source to the protruding portion

Methodology Applied
Scientific EffectDiffusion: Diffusion

Data Source

PatentEP3613636B1Vehicular interior lighting device and roof module
Publication Date: 2023.09.06 YAZAKI CORP
  • EP3613636B1 patent drawingFigure 1
  • EP3613636B1 patent drawingFigure 2
  • EP3613636B1 patent drawingFigure 3

AI summary

A vehicular interior lighting device (2) includes a main body portion (7) fixed to an inside surface of a roof, a light source (4) accommodated in the main body portion, a light shielding cover portion (8) constituting a housing with the main body portion and covering the light source from below, and 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. The light guide member has a diffusion portion (53) formed on a surface of the protruding portion facing downward and diffusing light, a first light guide portion (51) guiding light emitted from the light source to the protruding portion, and a reflecting portion (54) reflecting light guided by the first light guide portion toward the diffusion portion.