Automotive Light Guide Protrusions for Uniform Luminance

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Solution Overview

Problem

Automobile lighting devices with complex shapes, such as those surrounding power seat operation switches, often experience uneven luminance due to varying curvatures, which can reduce the quality and luxuriousness of the lighting experience.

Innovation Solution

A lighting device with a light guide having a complex shape and multiple protrusions on its surface, made from a light-transmitting resin like polycarbonate, that scatters light uniformly across the lighting region, mimicking the side shape of the power seat, ensuring consistent illumination.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If a light guide with a complex shape (mimicking power seat side shape) is used, then the lighting device can provide aesthetic value and facilitate operations, but the luminance becomes uneven between portions with different curvatures

Engineering Contradiction:
Improvecomplex shapeVSAvoidluminance uniformity
Core Design Contradiction:
ShapeVSIllumination intensity

Solution Approach 1:

The patent applies local quality by providing protrusions at specific locations on the light guide surface where curvature varies. The protrusions are strategically positioned to compensate for luminance differences in different regions, creating non-uniform local modifications that result in overall uniform luminance distribution across the complex-shaped light guide.

Inventive Principle:
Principle #3Local quality

2Illumination intensity

If protrusions are provided on the light guide surface to control light distribution, then luminance uniformity can be improved, but the device complexity increases

Engineering Contradiction:
Improveluminance uniformityVSAvoidlight guide structure
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The patent merges the light guide function with the light distribution control function by integrating protrusions directly into the light guide body. This combination eliminates the need for separate light distribution components, achieving uniform luminance while maintaining relatively simple device structure.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent changes the surface parameters of the light guide by adding protrusions with specific geometric characteristics (height, diameter, spacing). By adjusting these parameters, the light distribution is controlled to achieve uniform luminance across the complex shape without fundamentally changing the light guide's overall structure.

Inventive Principle:
Principle #35Parameter changes

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 lighting device with a complex shape that maintains uniform luminance, enhancing the quality and luxuriousness of the lighting experience without increasing costs by using a light guide with strategically placed protrusions to scatter light effectively and prevent leakage.

Implementation Method 1

multiple protrusions on its surface, made from a light-transmitting resin like polycarbonate, that scatters light uniformly across the lighting region

Methodology Applied
Scientific EffectLight scattering: Scattering

Data Source

PatentEP3719392B1Illumination device
Publication Date: 2023.01.04 ALPS ALPINE CO LTD
  • EP3719392B1 patent drawingFigure 1
  • EP3719392B1 patent drawingFigure 2
  • EP3719392B1 patent drawingFigure 3

AI summary

A lighting device includes a light guide that propagates incoming light, and a lighting panel including a lighting region. A front side of the lighting panel excluding the lighting region is configured to prevent transmission of light, the light guide is covered by the lighting panel, the lighting device is configured such that the light emitted from the light guide passes through the lighting region of the lighting panel for illumination, and surfaces of the lighting panel surrounding the light guide are white in color.