Vehicle Lamp Plate Light Guide Uniform Brightness

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Solution Overview

Problem

Vehicle lamps with plate-shaped light guides struggle to achieve uniform linear light emission and sufficient brightness, limiting design enhancement when turned on, as existing configurations either restrict sight direction or fail to secure adequate brightness.

Innovation Solution

A vehicle lamp configuration featuring a plate-shaped light guide with continuously arranged reflective elements of concave curved surfaces, where subsequent rows are positioned deeper from the first plate surface, allowing uniform total reflection and emission of light in a linear fashion, enhancing design properties by maintaining linear light appearance across varying sight directions and improving brightness uniformity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If a narrow groove-like reflective element or linear arrangement of reflective elements is formed on the plate surface, then linear light emission is achieved, but the sight direction in which linear light emission is observable is limited

Engineering Contradiction:
Improvelinear light emission patternVSAvoidsight direction range
Core Design Contradiction:
ShapeVSAdaptability or versatility

Solution Approach 1:

The reflective elements are given a substantially concave curved surface shape instead of flat or groove-like structures. This curvature enables the reflective elements to reflect light toward multiple directions including upward, forward, and backward directions, allowing linear light emission to be observed from various sight directions while maintaining the linear emission pattern.

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Shape

If the plate surface is textured to achieve linear light emission, then design property is improved, but sufficient brightness cannot be secured

Engineering Contradiction:
Improvelinear light emission patternVSAvoidbrightness
Core Design Contradiction:
ShapeVSIllumination intensity

Solution Approach 1:

The plate surface is divided into multiple reflective elements arranged in a specific pattern rather than using continuous texturing. Each reflective element acts as an independent light-reflecting unit with concave curved surface, and their collective arrangement produces linear light emission while maintaining high brightness through efficient light reflection.

Inventive Principle:
Principle #1Segmentation

3Illumination intensity

If multiple rows of reflective elements are arranged to improve brightness uniformity, then device complexity increases

Engineering Contradiction:
Improvebrightness uniformityVSAvoidreflective element arrangement
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

Different rows of reflective elements are positioned at different depths from the first plate surface according to their specific functional requirements. The second row is arranged deeper than the first row to optimize light reflection paths and achieve uniform brightness distribution, creating a graduated depth structure that improves performance while maintaining manageable complexity.

Inventive Principle:
Principle #3Local quality

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 described configuration enables the vehicle lamp to emit light linearly and uniformly along lines, improving design properties by maintaining linear light appearance and brightness consistency, even when the sight direction changes, and allowing for discrete optical fiber-like emission when turned on.

Implementation Method 1

a vehicle lamp configured to reflect light from a light source and incident on a plate-shaped light guide by a plurality of reflective elements

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 2

the plate-shaped light guide can appear to emit light in a manner substantially uniform in a front view of the lamp

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Data Source

PatentEP3875853B1Vehicle lamp
Publication Date: 2023.11.22 KOITO MFG CO LTD
  • EP3875853B1 patent drawingFigure 1
  • EP3875853B1 patent drawingFigure 2
  • EP3875853B1 patent drawingFigure 3

AI summary

Provided is a configuration that totally reflects light from a light source and incident on a plate-shaped light guide 32 by a plurality of reflective elements 32sC, 32sL, 32sR formed along lines L extending in an upper-lower direction on a first plate surface 32a, and then emits the light from a second plate surface 32b toward a front side of a lamp. In this case, the plurality of reflective elements are arranged in three rows in each of the lines L so as to be adjacent to each other in a left-right direction, and are each formed in a concave spherical surface shape. In addition, as compared to reflective elements 32sL, 32sR constituting two rows on left and right sides, reflective elements 32sC constituting a central row are formed at a deeper position from the first plate surface 32a. As a result, a brightness of reflected light from the reflective elements 32sC is brought close to brightness of reflected light from the reflective elements 32sL, 32sR, so that the plate-shaped light guide 32 appears to emit light linearly at a brightness that is substantially uniform along the lines L.