Tunable Scattering Layer for Sunlight Simulation

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Solution Overview

Problem

Existing lighting systems that mimic natural sunlight using Rayleigh-like scattering struggle with adaptability and tunability, as the scattering parameters are fixed by the type and number of nanoparticles and host material, limiting their ability to simulate varying sun-sky appearances and conditions.

Innovation Solution

A diffuser unit with a scattering layer comprising nanoscale scattering elements and a host material, where the scattering layer is adaptable through varying the relative refractive index and effective size of the nanoscale elements, and an electric field is applied to change the scattering cross-section, allowing for chromatic tunability of transmitted light.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If fixed nanoparticles and host material are used in Rayleigh-like scattering, then the scattering parameters are stable and reliable, but the adaptability and tunability of the lighting system are limited

Engineering Contradiction:
Improvetunability of scattering parametersVSAvoidcomplexity of adapting scattering layer
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies the dynamics principle by making the scattering layer tunable and adaptable. The host material's refractive index can be dynamically changed through temperature variation, allowing the scattering parameters to be adjusted without changing the nanoparticle composition. This enables the lighting system to adapt to different sun-sky conditions while maintaining a relatively simple fixed structure of nanoparticles embedded in the host material.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements parameter changes by varying the refractive index of the host material through temperature control. This changes the relative refractive index between nanoparticles and host material, thereby tuning the scattering cross-section and enabling different sun-sky appearance simulations without modifying the nanoparticle properties themselves.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If the scattering layer is made adaptable by varying refractive index and effective size, then the chromatic tunability is improved, but the device complexity increases

Engineering Contradiction:
Improvechromatic tunability of transmitted lightVSAvoidcomplexity of controlling scattering parameters
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent uses parameter changes by controlling the refractive index of the host material through temperature variation. This single parameter change (temperature) simultaneously controls the scattering cross-section and chromatic properties of the transmitted light, achieving chromatic tunability without requiring multiple complex control mechanisms.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces mechanical or chemical methods of changing scattering parameters with a thermal field approach. By using temperature to control the refractive index of the host material, the system achieves chromatic tunability through a simple thermal control mechanism rather than complex mechanical adjustments or chemical compositions.

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

3Adaptability or versatility

If electric field is applied to change scattering cross-section, then the dynamic simulation capability is improved, but the energy consumption increases

Engineering Contradiction:
Improvedynamic simulation of sun-sky conditionsVSAvoidenergy for adjusting scattering parameters
Core Design Contradiction:
Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

The patent replaces electric field control with thermal field control for adjusting scattering parameters. By using temperature variation to change the refractive index of the host material, the system achieves dynamic simulation capability through passive thermal management rather than active energy-consuming electric fields, thereby reducing energy consumption.

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

Solution Approach 2:

The system uses natural temperature variations and passive thermal control to adjust scattering parameters. The host material's refractive index changes automatically with temperature, allowing the lighting system to simulate different sun-sky conditions without requiring active energy input for parameter adjustment.

Inventive Principle:
Principle #25Self-service

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

Enables dynamic simulation of different sun-sky conditions by adjusting the scattering parameters, providing a tunable illuminance profile that mimics the color and intensity variations of natural sunlight throughout the day, enhancing visual comfort and ambiance.

Implementation Method 1

the panel receives the light from the light source and acts as a so-called Rayleigh diffuser, namely it diffuses incident light similarly to the earth atmosphere in clear-sky conditions

Methodology Applied
Scientific EffectRayleigh scattering: Rayleigh Scattering

Implementation Method 2

a liquid crystal layer with liquid crystals having an anisotropy in the index of refraction... and a pair of areal electrical contacts for providing an electric field for interacting with the liquid crystals

Methodology Applied
Scientific EffectElectric field effect on liquid crystals: Electric Field

Implementation Method 3

lighting units are known for simulating natural lighting, specifically sunlight illumination, that provide dichroic light to be emitted from a dichroic light exiting surface, where the dichroic light comprises a directional light portion of direct light having a first (lower) correlated color temperature (CCT) and a diffused light portion of diffused light having a second (larger) CCT

Methodology Applied
Scientific EffectLight transmission and diffusion: Scattering

Data Source

PatentEP3542195B1Tunability in sun-light imitating lighting systems
Publication Date: 2022.09.28 COELUX
  • EP3542195B1 patent drawingFigure 1A~1B
  • EP3542195B1 patent drawingFigure 2A~3
  • EP3542195B1 patent drawingFigure 4A~4B

AI summary

A diffuser unit (9) for providing a chromatically tunable transmitted light (33) by scattering of light that is incident on the diffuser unit (9) by illumination with white light (89) comprises a scattering layer (17) with a plurality of nanoscale scattering elements (19, 63) and a host material (21, 61) separating the nanoscale scattering elements (19, 63). The diffuser unit (9) further comprises a pair of areal electrical contacts (23') for providing an electric field (27) and at least one of the areal electrical contacts (23') is configured to be transparent in the visible wavelength range. The scattering layer (17) is configured to be adaptable in the ensemble light scattering cross-section amount by varying the relative refractive index and/or the effective size of the nanoscale scattering elements (19, 63), thereby providing a changeability in the spectrum of the transmitted light (33).