Double Diffuser LED Module for Homogeneous Light Mixing

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Solution Overview

Problem

LED modules with multiple LED chips of different emission spectra face challenges in achieving homogeneous light mixing, leading to negative shading effects and localized color separation when viewed from the edge region of a diffuser, which affects the perceived color temperature and homogeneity of the emitted light.

Innovation Solution

A two-shell diffuser system comprising a primary diffuser element that encloses the LED chips like a hood and a secondary diffuser element spaced apart with an air gap, where the primary diffuser is mechanically attached and has a reduced wall thickness above the LED chips, and both diffuser elements can be made of plastic or glass materials, ensuring improved light mixing and color homogeneity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If a single diffuser element is used to cover LED chips with different emission spectra, then light mixing is attempted, but negative shading effects occur and localized color separation is visible at the edge region

Engineering Contradiction:
Improvecolor homogeneityVSAvoidnegative shading effects
Core Design Contradiction:
Stability of the object's compositionVSObject-generated harmful factors

Solution Approach 1:

The diffuser is divided into two separate elements: a first diffuser element directly covering the LED chips and a second diffuser element positioned further away. This segmentation allows each diffuser to perform a specific function - the first for initial light scattering and the second for final homogeneous mixing, eliminating the negative shading effects of a single diffuser design.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

An air gap is introduced as an intermediary between the first and second diffuser elements. This air gap acts as a medium that allows light to propagate and mix between the two diffusers, enabling the second diffuser to receive light from the first and further scatter it to achieve uniform color distribution without direct contact between the diffusers.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Illumination intensity

If the first diffuser element is positioned close to the LED chips, then light scattering is effective, but the edge region becomes visible and color separation occurs

Engineering Contradiction:
Improvelight scattering efficiencyVSAvoidcolor homogeneity
Core Design Contradiction:
Illumination intensityVSStability of the object's composition

Solution Approach 1:

The solution transitions from a single-plane diffuser arrangement to a three-dimensional configuration with two diffusers at different positions along the light propagation path. The first diffuser is close to the LEDs for effective scattering, while the second diffuser is positioned further away to ensure homogeneous mixing, utilizing the spatial dimension to resolve the contradiction.

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

3Adaptability or versatility

If multiple LED chips with different emission spectra are integrated on a common carrier, then adjustable color temperature is achieved, but homogeneous light mixing becomes difficult

Engineering Contradiction:
Improvecolor temperature adjustmentVSAvoidlight mixing homogeneity
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The diffuser system is segmented into two functional parts: the first diffuser element that receives light from multiple LED chips with different spectra, and the second diffuser element that further mixes this light. This segmentation enables effective mixing of multiple spectra while maintaining color temperature adjustability through independent control of the LED chips.

Inventive Principle:
Principle #1Segmentation

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 two-shell diffuser system effectively mixes light from LED chips with different spectra, eliminating localized color separation and enhancing the perceived color homogeneity and temperature of the emitted light, providing a more uniform and aesthetically pleasing illumination.

Implementation Method 1

a first diffuser element (10), which diffusely scatters light from the at least one LED chip

Methodology Applied
Scientific EffectLight scattering: Scattering

Implementation Method 2

LED modules consisting of at least one blue LED, which generates white light by means of wavelength conversion means arranged on the LED

Methodology Applied
Scientific EffectWavelength conversion: Photoluminescence

Implementation Method 3

from this, preferably with the formation of an air gap, separated

Methodology Applied
Scientific EffectLight propagation: Light

Data Source

PatentEP2556286B1LED module having a double diffuser
Publication Date: 2018.10.17 TRIDONIC JENNERSDORF GMBH
  • EP2556286B1 patent drawingFigure 1a~1b
  • EP2556286B1 patent drawingFigure 2~3

AI summary

The invention relates to a LED module (7) which comprises: at least one LED chip (20, 21) mounted on a substrate, a first diffuser element (10) which scatters the light from the at least one LED chip (20, 21) diffusely, and a second diffuser element (8) which when viewed in the light beam direction is outside the first diffuser element (10) and is separated therefrom, preferably forming an air gap.