Lighting Device Micro-Lens Array UGR Reduction

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Solution Overview

Problem

Current indoor flat lighting devices fail to meet the Unified Glare Rating (UGR) standard below 19 due to excessive light flux emission between 65° and 90°, causing eye discomfort, despite the use of reflecting shades or diffusion plates.

Innovation Solution

A lighting device configuration that incorporates a micro-lens array on a transparent optical plate, with adjustable sag and Fill Factor, is used to reduce light flux emission between 65° and 90° by forming a natural air gap between the diffusing plate and the optical plate, optimizing light distribution and UGR.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a diffusion plate is used to reduce hot spot and emit uniform light, then illumination uniformity is improved, but light flux emission between 65° and 90° is not sufficiently reduced causing UGR to remain above 19

Engineering Contradiction:
Improveillumination uniformityVSAvoidUGR value
Core Design Contradiction:
Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

The optical plate is segmented into multiple micro-lenses arranged in an array, where each micro-lens independently controls light rays within specific angular ranges. This segmentation allows precise control over light distribution in different directions, particularly reducing light flux in the 65°-90° range while maintaining uniform illumination in other directions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the optical plate have different local optical properties through varying micro-lens parameters (sag, diameter, spacing). The micro-lenses are designed with specific local characteristics to control light refraction angles, ensuring that light flux is reduced in the harmful 65°-90° range while maintaining or enhancing illumination in desirable directions.

Inventive Principle:
Principle #3Local quality

2Object-affected harmful factors

If reflecting shades or louver are used to reduce light spreading angle, then UGR is reduced, but device complexity and structural complexity increase

Engineering Contradiction:
ImproveUGR valueVSAvoidstructural complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent replaces mechanical light control structures (reflecting shades, louver) with an optical system based on micro-lenses. The micro-lens array inherently controls light direction through refraction without requiring movable or complex mechanical components, thereby reducing device complexity while achieving UGR reduction.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent controls light distribution by changing optical parameters of the micro-lenses (sag, diameter, spacing, refractive index) rather than using complex mechanical adjustments. By optimizing these parameters, the system achieves precise control over light angles and UGR values with a simple, static structure.

Inventive Principle:
Principle #35Parameter changes

3Object-affected harmful factors

If micro-lens array is added to control light flux, then UGR is reduced, but device complexity increases

Engineering Contradiction:
ImproveUGR valueVSAvoiddevice complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The optical plate combining micro-lens array is merged with the diffusing plate into a single integrated component. This merging eliminates the need for separate light control mechanisms and simplifies the overall device structure while maintaining effective UGR reduction through the micro-lens array's optical control capabilities.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The optical plate serves multiple functions simultaneously: it acts as a diffusing plate for uniform light distribution, a light control element for reducing light flux in specific angles, and an optical guide for directing light. This multi-functionality reduces the need for additional components, thereby minimizing device complexity while achieving UGR reduction.

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

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 configuration effectively reduces UGR to below 19, enhancing illumination intensity and light efficiency while maintaining compliance with indoor lighting standards, by refracting and collecting light through the micro-lens pattern and air gap, resulting in improved glare reduction and light distribution.

Implementation Method 1

a configuration wherein a micro-lens array is patterned on a transparent plate... by refracting and collecting light through the micro-lens pattern

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 2

forming a natural air gap between the diffusing plate and the optical plate, optimizing light distribution and UGR

Methodology Applied
Scientific EffectLight collection and redistribution: Lens

Data Source

PatentEP2726776B1Lighting device
Publication Date: 2021.03.31 LG INNOTEK CO LTD
  • EP2726776B1 patent drawingFigure 1~3
  • EP2726776B1 patent drawingFigure 4(a)~5
  • EP2726776B1 patent drawingFigure 6~8

AI summary

The present invention relates to an lighting device capable of reducing UGR (Unified Glare Rating) characterized by comprising the frame portion formed at the peripheral area in which the printed circuit board mounted with a light source and the light source are arranged, and the inserting portion into which the diffusing plate and the optical plate are inserted at the inside of the frame portion simultaneously. Particularly, an air gap can be formed on the closed adhered surface of the optical plate and the diffusing plate.