Saddle-Shaped Reflector for Street Lighting

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Solution Overview

Problem

Existing street and road lighting devices using gas-discharge lamps often dazzle drivers due to limited design opportunities for reflector arrangements, resulting in inadequate light distribution and increased risk of driver distraction.

Innovation Solution

A lighting device featuring a saddle-shaped reflector and compact light sources, such as LEDs, is mounted below the driver's eye level, with a reflector design that provides wide light distribution parallel to the illuminated surface and minimizes dazzling risks through adjustable light emission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If gas-discharge lamps are used to provide required luminance, then illumination intensity is improved, but device complexity increases and design opportunities for reflector arrangement are limited

Engineering Contradiction:
ImproveluminanceVSAvoiddesign opportunities for reflector arrangement
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The patent changes the type of light source from gas-discharge lamp to LED, representing a fundamental parameter change in the lighting technology. This substitution maintains required luminance while enabling new reflector design possibilities due to the compact LED geometry and different emission characteristics

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs a saddle-shaped reflector with specific curved surfaces designed to work optimally with the compact LED light source. The curved geometry of the reflector is specifically adapted to the point-like emission of LEDs, creating design opportunities that were not available with linear gas-discharge lamps

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Area of stationary object

If lighting device is mounted at low height to illuminate streets and roads, then illumination coverage is improved, but risk of dazzling drivers increases

Engineering Contradiction:
Improveillumination coverageVSAvoidrisk of dazzling drivers
Core Design Contradiction:
Area of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by creating specific dark zones in the light distribution pattern at driver eye level, while maintaining bright illumination in the road surface areas. The saddle-shaped reflector is designed to direct light locally toward the road while avoiding the horizontal plane where drivers are positioned

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent enables dynamic adjustment of the light distribution pattern through adjustable reflector elements or positioning mechanisms. This allows the lighting system to adapt to different mounting conditions and traffic situations, optimizing both illumination coverage and driver safety

Inventive Principle:
Principle #15Dynamics

3Device complexity

If compact LED light source is used instead of gas-discharge lamp, then device complexity is reduced and reflector design flexibility is improved, but illumination intensity may be compromised

Engineering Contradiction:
Improvereflector design flexibilityVSAvoidluminance
Core Design Contradiction:
Device complexityVSIllumination intensity

Solution Approach 1:

The patent compensates for the lower luminance of individual LEDs by utilizing the three-dimensional saddle-shaped reflector geometry to distribute light over a wide area. The reflector transforms the point-source LED emission into a broad illumination pattern, achieving high illuminance on the road surface through spatial distribution rather than relying on high source luminance

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 a broad, homogeneous light distribution while reducing the risk of dazzling drivers by utilizing a compact LED light source and a saddle-shaped reflector, allowing for precise adjustment of light emission based on mounting conditions.

Implementation Method 1

at least one light source comprising at least one light emitting diode

Methodology Applied
Scientific EffectLight emitting diode: Light Emitting Diode

Implementation Method 2

at least one reflector comprising an essentially saddle-shaped reflection surface, wherein the light source is arranged in such a way that at least a part of the light emitted by the light source is directed to the reflection surface of the reflector; and wherein the light is reflected by the reflection surface

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP2894392B1Lighting device for illumination streets, roads or paths
Publication Date: 2021.06.09 ZG LIGHTING FRANCE SAS
  • EP2894392B1 patent drawingFigure 1
  • EP2894392B1 patent drawingFigure 2
  • EP2894392B1 patent drawingFigure 3

AI summary

Lighting device (100) for illuminating streets, roads or paths, comprising: at least one light source (220) comprising at least one light emitting diode; at least one reflector (120) comprising an essentially saddle-shaped reflection surface (150); wherein the light source (220) is arranged such that at least a part of the emitted light is directed to the reflection surface (150) of the reflector (120); and wherein the light is reflected by the reflection surface (150) in such a way that a wide light distribution of the lighting device (100) is provided at least in a direction parallel to a surface to be illuminated and perpendicular to a main axis (160) of the reflection surface (150).