Diffuse Reflective LED Luminaire for Glare Reduction

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Solution Overview

Problem

Current LED road lighting luminaires exhibit a pixelated appearance and high glare/brightness contrast due to individual lenses, leading to inefficient light distribution and glare issues.

Innovation Solution

A lighting system comprising a light source, a first diffuse reflective element that tapers from one end to another, and a lens, with an optional second specular reflective element that redirects light to the lens, creating a wide beam with improved light distribution and reduced glare by blocking light in undesired directions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If individual lenses are used for each LED in an array, then precise illumination of the road surface is achieved, but a pixelated appearance and high glare/brightness contrast occur

Engineering Contradiction:
Improveillumination precisionVSAvoidglare and pixelated appearance
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

Multiple individual LED-lens units are merged into a single luminaire housing with a common optical system. The reflective elements and single lens integrate light from multiple LEDs into a unified beam, eliminating the pixelated appearance while maintaining precise illumination control.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

Reflective elements (first and second reflective elements) are introduced as intermediaries to redirect and redistribute light from individual LEDs. These reflectors act as mediators that smooth out the light distribution, reducing brightness contrast and glare while preserving illumination precision.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Power

If a large array of medium power LEDs is used, then sufficient light output is achieved, but the luminaire exhibits high glare and brightness contrast

Engineering Contradiction:
Improvelight outputVSAvoidglare and brightness contrast
Core Design Contradiction:
PowerVSObject-affected harmful factors

Solution Approach 1:

Different regions of the optical system are assigned different functions: the first reflective element collects light from multiple LEDs, the second reflective element redirects light to fill dark areas, and the lens focuses the redistributed light. This local differentiation of optical qualities enables high light output without glare.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The optical system transitions from direct LED-to-lens illumination to a multi-dimensional light path involving multiple reflections. Light travels through additional spatial dimensions via the reflective elements, enabling redistribution that reduces brightness contrast while maintaining total light output.

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

3Illumination intensity

If multiple reflective elements are added to redirect light, then light distribution is improved and glare is reduced, but device complexity increases

Engineering Contradiction:
Improvelight distribution uniformityVSAvoidnumber of optical components
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The reflective elements serve multiple functions: the first reflective element both collects light from LEDs and redirects it toward the lens, while the second reflective element simultaneously fills dark areas and controls beam shape. This multi-functionality reduces the need for additional separate components.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The reflective elements are designed with specific geometric parameters (angles, curvatures, positions) that optimize light redistribution. By carefully controlling these parameters, the system achieves improved light distribution uniformity without requiring excessive numbers of components.

Inventive Principle:
Principle #35Parameter changes

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 system provides a wide beam with even light distribution at high angles, reducing glare and allowing for easy tuning of the beam shape, resulting in improved visual comfort and efficiency in street lighting.

Implementation Method 1

the first reflective surface is diffuse reflective

Methodology Applied
Scientific EffectDiffuse reflection: Reflection

Implementation Method 2

the second reflective element is configured to specularly reflect at least part of the light source light that reaches the second reflective element (to the lens)

Methodology Applied
Scientific EffectSpecular reflection: Reflection

Implementation Method 3

the lens is configured (especially at the first end) to beam shape at least part of the light source light emanating from the reflective element and the light source

Methodology Applied
Scientific EffectRefraction: Refraction

Data Source

PatentEP3601877B1High visual comfort road and urban LED lighting
Publication Date: 2021.08.11 SIGNIFY HOLDING BV
  • EP3601877B1 patent drawingFigure 1A
  • EP3601877B1 patent drawingFigure 1B~1C
  • EP3601877B1 patent drawingFigure 1D~1E

AI summary

The invention provides a lighting system (1000) comprising a light source (10), configured to provide light source light (11), a first reflective element (210), a second reflective element (220), and a lens (240), wherein: - the first reflective element (210) tapers from a first end (211) to a second end (212), wherein the first reflective element (210) comprises a first reflective surface (213) bridging the distance between the first end (211) and the second end (212), wherein the first reflective surface (213) is diffuse reflective, and wherein the light source (10) is at least partially circumferentially surrounded by the first reflective surface (213); - the light source (10) is configured closer to the second end (212) than to the first end (211), and wherein the light source (10) is configured to direct at least part of the light source light (11) in the direction of the first end (211); - the lens (240) is configured to beam shape at least part of the light source light (11) emanating from the reflective element (210) and the light source (10); and - the second reflective element (220) is configured to redirect part of the light source light (11) to the lens (240), wherein the second reflective element is configured to specularly reflect at least part of the light source light (11) that reaches the second reflective element (220).