Vehicle Lighting Unit with Bent Light Guide Reflection

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Solution Overview

Problem

Conventional vehicle lighting units with elongated light guides illuminated by a single light source at one end suffer from light attenuation and non-uniform light emission, requiring multiple light sources and concealing members, which increase parts complexity and restrict placement within a vehicle body.

Innovation Solution

A vehicle lighting unit design featuring reflection surfaces in the bending sections of a U-shaped light guide, allowing light from two sources to enter and be reflected along the guide, reducing the need for multiple substrates and concealing members, while maintaining uniform illumination.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single light source is disposed at one end of the light guide, then the device complexity is reduced, but the uniformity of light emission deteriorates due to light attenuation

Engineering Contradiction:
Improvenumber of light sourcesVSAvoiduniformity of light emission
Core Design Contradiction:
Device complexityVSIllumination intensity

Solution Approach 1:

The patent combines the functions of multiple light sources into a single integrated light source unit. The first and second light sources are mounted on the same substrate with their emission surfaces facing the same direction, allowing them to be controlled as one unit while maintaining separate light guiding paths. This merging approach reduces device complexity while the separate light guiding sections ensure uniform light distribution.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent segments the light guiding function into two separate light guiding sections (first and second light guiding sections) that extend in different directions from the bending section. Each section has its own light incident surface receiving light from the integrated light source, allowing independent optimization of light paths to achieve uniform emission across different directions while using a single light source unit.

Inventive Principle:
Principle #1Segmentation

2Illumination intensity

If light sources are disposed at two separate locations to illuminate both ends of the light guide, then the uniformity of light emission is improved, but the device complexity increases due to multiple substrates

Engineering Contradiction:
Improveuniformity of light emissionVSAvoidnumber of substrates
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The patent merges multiple light sources into a single substrate mounting structure. The first and second light sources are both mounted on the same substrate, with their emission surfaces facing the same direction. This integration eliminates the need for multiple separate substrates while maintaining the capability to illuminate different directions through the segmented light guiding sections.

Inventive Principle:
Principle #5Merging (Combining)

3Object-affected harmful factors

If concealing members are added to hide light sources at two locations, then the light sources cannot be directly observed, but the device complexity increases by the number of concealing members

Engineering Contradiction:
Improvevisibility of light sourcesVSAvoidnumber of concealing members
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent combines multiple light sources into a single integrated unit with emission surfaces facing the same direction. This merging eliminates the need for separate concealing members for each light source, as the unified structure can be concealed more efficiently or designed to be aesthetically pleasing without additional parts.

Inventive Principle:
Principle #5Merging (Combining)

4Area of stationary object

If the end of the light guide is located at the end of the lighting chamber, then the lighting coverage is maximized, but this is prevented by the provision of light sources at the end of the light guide

Engineering Contradiction:
Improvelighting coverageVSAvoidplacement constraints
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The patent inverts the conventional arrangement by having the light incident surfaces of the light guiding sections face away from the light source direction. The first and second light guiding sections extend in different directions from the bending section, with their light incident surfaces oriented to receive light from the integrated light source while allowing the light guide ends to reach the lighting chamber boundaries for maximum coverage.

Inventive Principle:
Principle #13The other way round (Inversion)

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 uniform light emission along the light guide with fewer parts, enabling flexible placement within a vehicle body by using a single substrate for both light sources and eliminating the need for concealing members.

Implementation Method 1

a first reflection surface (R1) configured to reflect light incident thereon in a first direction (D1); and a second reflection surface (R2) configured to reflect light incident thereon in a second direction (D2)

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP2762770B1Vehicle lighting unit
Publication Date: 2021.08.25 STANLEY ELECTRIC CO LTD
  • EP2762770B1 patent drawingFigure 1
  • EP2762770B1 patent drawingFigure 2
  • EP2762770B1 patent drawingFigure 3

AI summary

A vehicle lighting unit (1) can be configured to be capable of disposing a bent elongated light guide (4) to the end of a lighting chamber of the lighting unit while the uniformity of light emission state across the entire length of the bent elongated light guide (4) can be ensured with less part number as compared with the conventional lighting unit. The vehicle lighting unit (1) can include LEDs (5) mounted on a substrate (6), and an elongated inner lens configured to receive light emitted from the LEDs (5) and guide the light along its lengthwise direction so as to emit light from its front surface. The inner lens can include a first light guiding section (41) extending in the left-to-right direction and a second light guiding section (42) extending in the vertical direction, and a bending section (40) between the first and second light guiding sections (41, 42). The bending section (40) can include a first reflection surface (R1) and a second reflection surface (R2). The first reflection surface (R1) can internally reflect light from the rear side toward the first light guiding section (41) substantially in the horizontal direction. The second reflection surface (R2) can internally reflect the light from the rear side toward the second light guiding section (42) substantially in the vertical direction. The LEDs (5) can include a first LED (51) and a second LED (52). The first LED (51) can be disposed in the rear of the first reflection surface (R1) of the bending section (40). The second LED (52) can be disposed in the rear of the second reflection surface (R2) of the bending section (40).