Vehicle Lamp Light Guide Reflection Design

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Solution Overview

Problem

Conventional vehicle lamps fail to ensure that light from the light source reliably reaches the light guide, resulting in insufficient light distribution and design inefficiencies.

Innovation Solution

A vehicle lamp design featuring a first light guide with a reflecting surface that directs light towards a second light guide, which extends outward in the vehicle width direction, ensuring that light is positively incident on the second guide and providing uniform light emission without leakage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If the reflector is designed to suppress leakage light to the side, then the light distribution forward is improved, but the light amount reaching the light guide becomes insufficient

Engineering Contradiction:
Improvelight distribution forwardVSAvoidlight amount reaching light guide
Core Design Contradiction:
Illumination intensityVSQuantity of substance

Solution Approach 1:

A reflecting surface is introduced as an intermediary element between the light source and the light guide. This reflecting surface captures the leakage light that would otherwise be lost and redirects it toward the light guide, effectively mediating the light transfer process. The solution resolves the contradiction by adding this intermediate reflecting component that recovers otherwise wasted light and channels it to the intended destination.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Loss of energy

If the reflecting surface is provided at the center of the first light guide, then light reflection is maximized, but the light flux becomes bifurcated and emission uniformity is compromised

Engineering Contradiction:
Improvelight reflection efficiencyVSAvoidlight emission uniformity
Core Design Contradiction:
Loss of energyVSStability of the object's composition

Solution Approach 1:

The reflecting surface is strategically positioned at a specific location within the first light guide rather than at the center. This localized placement ensures that the reflecting surface operates in an optimal position where it can effectively redirect light without causing bifurcation of the light flux. The solution applies local quality by making the reflecting surface's position a specific design parameter that balances reflection efficiency with emission uniformity.

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

This configuration allows for reliable light distribution to the second light guide, enhancing the light's reach and achieving a high design effect with even light emission.

Implementation Method 1

The first light guide has a reflecting surface configured to reflect a part of incident light from the light source toward the connection end of the second light guide

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP3553370B1Vehicle lamp
Publication Date: 2021.08.04 TOYOTA JIDOSHA KK
  • EP3553370B1 patent drawingFigure 1
  • EP3553370B1 patent drawingFigure 2
  • EP3553370B1 patent drawingFigure 3

AI summary

An front (FR) turn lamp (10) that is a vehicle lamp includes a first light guide (12) and a second light guide (13). The first light guide (12) is disposed in front of a light source (11) in the direction of an optical axis (C1). A lens surface (12A) opposed to the light source (11) is formed at the rear end in the direction of the optical axis (C1), and a light emission surface (12B) is formed at the front end in the direction of the optical axis (C1). The second light guide (13) has a connection end (13C) connected to a vehicle width direction outer side surface (12C) of the first light guide (12) and extends outward in the vehicle width direction from the connection end (13C). A reflecting surface (13A) is formed at the rear in a vehicle longitudinal direction, and a light emission surface (13B) is formed at the front in the vehicle longitudinal direction. The first light guide (12) has a reflecting surface (15) configured to reflect a part of incident light from the light source (11) toward the connection end (13C) of the second light guide (13).