LED Lighting Device with Reflective Top Plate for Eye Safety

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Solution Overview

Problem

Conventional LED lighting devices do not effectively mitigate direct eye exposure to intense light sources, which can cause discomfort and vision obstruction, especially in indirect lighting setups.

Innovation Solution

A lighting device design featuring a heat sink with a reflective top plate and inclined bottom plate, along with an optical body and cover, that redirects and diffuses light from multiple LED source units, ensuring light is emitted in a controlled direction and reducing direct visibility of the LEDs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If direct lighting is used to maximize luminous efficiency, then light output is improved, but direct eye exposure to intense light causes discomfort and vision obstruction

Engineering Contradiction:
Improveluminous efficiencyVSAvoiddirect eye exposure to intense light
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

A reflective top plate with a conical reflective surface is introduced as an intermediary between the LED light source and the external environment. This reflective surface redirects light that would otherwise travel directly toward the observer, converting direct light paths into reflected paths that achieve indirect lighting效果, thereby protecting eyes from direct exposure while maintaining luminous efficiency

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

Instead of allowing light to travel directly from the source to the target (direct lighting), the design inverts the light path by using a reflective surface to bounce light indirectly toward the target area. This inversion transforms the direct lighting approach into an indirect lighting solution that eliminates harmful direct eye exposure while preserving lighting effectiveness

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

2Object-affected harmful factors

If indirect lighting is used to protect eyes from direct light exposure, then eye safety is improved, but light intensity and luminous efficiency are reduced

Engineering Contradiction:
Improvedirect eye exposure to intense lightVSAvoidluminous efficiency
Core Design Contradiction:
Object-affected harmful factorsVSProductivity

Solution Approach 1:

The reflective top plate serves as an intermediary that captures and redirects light rather than allowing it to be lost. By positioning the reflective surface at a 45-degree angle, the system efficiently redirects light that would otherwise be wasted or cause direct exposure, thereby maintaining high luminous efficiency while achieving eye protection

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The design changes the directional parameters of light propagation by using a conical reflective surface with specific angular geometry. This parameter change redirects light at controlled angles, ensuring that light reaches the intended target area with high efficiency while preventing direct line-of-sight exposure to the light source

Inventive Principle:
Principle #35Parameter changes

3Illumination intensity

If multiple light source units are provided to increase illumination, then lighting coverage is improved, but direct visibility of multiple LED sources increases eye discomfort

Engineering Contradiction:
Improvelighting coverageVSAvoiddirect visibility of LED sources
Core Design Contradiction:
Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

The lighting system is segmented into multiple independent light source units, each equipped with its own reflective top plate. This segmentation allows each LED source to be individually managed and redirected, ensuring comprehensive lighting coverage while preventing any single direct LED exposure point from causing eye discomfort

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Each light source unit is paired with a reflective top plate that acts as an intermediary, redirecting light from multiple sources simultaneously. This systematic application of the intermediary principle across multiple sources ensures that increased illumination coverage does not come at the cost of increased direct eye exposure

Inventive Principle:
Principle #24Intermediary (Mediator)

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 effectively protects users' eyes from direct LED light exposure by redirecting light through a conical reflective surface and inclined surfaces, enhancing luminous efficiency and user safety.

Implementation Method 1

a top plate being disposed on the opening of the heat sink and including a reflective surface which reflects light from the light source unit in a particular direction

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 2

a heat sink including an inner surface on which the substrate of the light source unit is disposed

Methodology Applied
Scientific EffectThermal radiation: Thermal Radiation

Implementation Method 3

a plurality of heat radiating fins are disposed on the outer surface of the heat sink

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 4

an optical body which is disposed between the heat sink and the reflective surface of the top plate and excites, diffuses or collects light from the light source unit

Methodology Applied
Scientific EffectDiffusion: Diffusion

Implementation Method 5

The lens excites, diffuses or collects the light from the reflective surface of the top plate

Methodology Applied
Scientific EffectRefraction: Refraction

Data Source

PatentEP2418423B1Lighting device
Publication Date: 2019.05.29 LG INNOTEK CO LTD
  • EP2418423B1 patent drawingFigure 1
  • EP2418423B1 patent drawingFigure 2
  • EP2418423B1 patent drawingFigure 3

AI summary

A lighting device may be provided that includes a lighting device including: a light source unit including a substrate and a light emitting device disposed on the substrate; a heat sink including an inner surface on which the light source unit is disposed and at least one opening; and a top plate being disposed on the heat sink and including a reflective surface which reflects light from the light source unit in a particular direction.