Vehicle Lamp Light Guide Layout for Uniform Multi-Color Luminance

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing vehicle lamps experience luminance unevenness in light output from partitioned sections, which affects the uniformity and aesthetic appeal of the lighting effect.

Innovation Solution

A vehicle lamp design incorporating a light guide plate with multiple light-exiting portions and a low-luminance portion between them, combined with a wavelength conversion member that converts the light emission peak wavelength from 420 nm to 550 nm to 540 nm to 700 nm, reducing luminance unevenness by diffusing light uniformly across the extraction region.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a light guide member with partitioned sections is used to output light in different colors from each section, then the vehicle lamp can achieve multi-color light output and design flexibility, but luminance unevenness occurs within each light-exiting portion

Engineering Contradiction:
Improvemulti-color light output capabilityVSAvoidluminance uniformity
Core Design Contradiction:
Adaptability or versatilityVSIllumination intensity

Solution Approach 1:

The light guide plate is divided into multiple light-exiting portions, each corresponding to a light source. This segmentation allows different colors of light to be emitted from different sections while maintaining uniform luminance within each section through the structured design of the light guide plate and wavelength conversion member

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the light guide plate are designed with different properties: light-exiting portions have high luminance for light emission, while low-luminance portions have reduced luminance to prevent light leakage. The wavelength conversion member is also designed with local quality variations to convert light wavelengths specifically in the light-exiting portions, ensuring uniform luminance distribution

Inventive Principle:
Principle #3Local quality

2Illumination intensity

If light is extracted from a continuous light guide surface, then the light output is uniform, but it is impossible to achieve partitioned multi-color light output

Engineering Contradiction:
Improveluminance uniformityVSAvoidpartitioned multi-color light output
Core Design Contradiction:
Illumination intensityVSAdaptability or versatility

Solution Approach 1:

The continuous light guide surface is segmented into multiple light-exiting portions separated by low-luminance portions. This segmentation enables different colors of light to be emitted from different sections while maintaining uniform luminance within each section through the structured design

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The wavelength conversion member acts as an intermediary between the light sources and the light guide plate. It converts the light from light sources to different wavelengths and directs it to specific light-exiting portions, enabling partitioned multi-color light output while maintaining luminance uniformity

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 achieves reduced luminance unevenness and enhanced uniformity of light output, improving the visual appearance and functionality of the vehicle lamp.

Implementation Method 1

a wavelength conversion member that converts the light emission peak wavelength from 420 nm to 550 nm to 540 nm to 700 nm

Methodology Applied
Scientific EffectWavelength conversion: Fluorescence

Implementation Method 2

reducing luminance unevenness by diffusing light uniformly across the extraction region

Methodology Applied
Scientific EffectLight diffusion: Diffusion

Data Source

PatentEP4368876B1Vehicle lamp
Publication Date: 2026.02.25 NICHIA CORP
  • EP4368876B1 patent drawingFigure 1A
  • EP4368876B1 patent drawingFigure 1B
  • EP4368876B1 patent drawingFigure 2A

AI summary

A vehicle lamp includes a light guide plate including a plurality of light-exiting portions and a low-luminance portion, which is located between adjacent light-exiting portions and outputs light having luminance lower than luminance of light exiting from the light-exiting portion; a plurality of light sources each emit light having a light emission peak wavelength in a range from 420 nm to 550 nm to enter the light guide plate; and a wavelength conversion member that is disposed on the plurality of light-exiting portions and emits light having a light emission peak wavelength in a range from 540 nm to 700 nm by converting a wavelength of the light exiting from the light-exiting portion.