LED Lighting Device Peripheral Reflector Geometry

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Solution Overview

Problem

Existing outdoor lighting devices, particularly street lighting, suffer from inefficiencies due to dispersed light beams and the screen effect of light sources, leading to significant loss of luminous energy, as they are not effectively directed towards the target.

Innovation Solution

The design incorporates LED light sources with their Full Width at Half Maximum (FWHM) luminous spectrum totally reflected by strategically shaped reflecting surfaces, ensuring that most light beams are directed towards the target, minimizing dispersion and increasing luminous efficacy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If traditional light sources (incandescent, halogen, fluorescent) are used, then the light beams are emitted in all directions providing omnidirectional illumination, but the light sources act as screens blocking most light beams causing significant energy loss

Engineering Contradiction:
Improveomnidirectional illuminationVSAvoidlight beam loss due to screen effect
Core Design Contradiction:
Illumination intensityVSLoss of energy

Solution Approach 1:

The invention extracts the light source from the center position and places it at the periphery of the reflector system. This peripheral positioning removes the light source from the path of the light beams it generates, eliminating the screen effect that caused energy loss while maintaining omnidirectional illumination capability through the reflector geometry

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention introduces a reflector as an intermediary element between the light source and the target area. The reflector captures light beams emitted in all directions and redirects them toward the desired illumination zone, converting the omnidirectional emission into directed illumination while preventing the light source itself from blocking the beams

Inventive Principle:
Principle #24Intermediary (Mediator)

2Area of stationary object

If light sources are placed at a considerable distance from the target, then the illumination covers a larger area, but the light beams become dispersed reducing lighting efficiency

Engineering Contradiction:
Improveillumination coverage areaVSAvoidlighting efficiency
Core Design Contradiction:
Area of stationary objectVSProductivity

Solution Approach 1:

The invention employs a movable lighting device that can dynamically adjust its position and orientation relative to the target area. This dynamic positioning allows the system to optimize the balance between coverage area and beam concentration, maintaining high lighting efficiency while adapting to different illumination requirements and distances

Inventive Principle:
Principle #15Dynamics

3Loss of energy

If reflecting surfaces are added to redirect light beams towards the target, then the luminous efficacy is considerably improved, but the device complexity increases

Engineering Contradiction:
Improveluminous efficacyVSAvoidstructure complexity with reflecting surfaces
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The invention segments the reflector surface into multiple distinct zones, each with specific geometric characteristics optimized for different functions: some zones redirect light at specific angles, others concentrate beams, and some areas provide diffuse reflection. This segmentation allows complex optical functionality to be achieved through modular geometric design rather than a single complicated surface

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention utilizes curved and shaped reflecting surfaces with specific geometric profiles designed to redirect light beams in predetermined patterns. The curved geometries naturally guide light rays through reflection to achieve concentration and directionality without requiring additional optical elements, simplifying the overall device structure while maintaining high luminous efficacy

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 approach significantly enhances luminous efficacy by maximizing the recovery of light beams that would otherwise be lost, reducing the screen effect of the light source, and allowing for tailored reflection and projection configurations for improved light distribution.

Implementation Method 1

one or more reflecting surfaces (5) designed to at least partially reflect the light beams (40). At least a first one (8) of the LED sources has the FWHM of its luminous spectrum totally reflected by at least one of the reflecting surfaces (5) and totally projected towards a target

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP2376830B1Lighting device
Publication Date: 2018.09.05 ARIANNA
  • EP2376830B1 patent drawingFigure 1~2
  • EP2376830B1 patent drawingFigure 3~4
  • EP2376830B1 patent drawingFigure 5~6

AI summary

An outdoor lighting device for lighting a target (O), particularly for use in street lighting, comprising a support structure (2) and a lighting unit (3, 103, 503) stably associated with the support structure (2) and having one or more light beam sources (4) of LED type, with preset FWHM values, and one or more reflecting surfaces (5, 105, 205, 305, 405, 505) designed to at least partially reflect light beams. At least a first one (8, 108, 508) of the LED sources (4) has the FWHM of its luminous spectrum totally reflected by one or more of the reflecting surfaces (5, 105, 205, 305, 405, 505) and totally projected towards the target (O) for increased lighting efficiency.