Artificial Illumination Device Natural Light Replication

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Solution Overview

Problem

Existing artificial illumination devices fail to accurately replicate the natural light from the sun and sky, as they do not produce shadows that are parallel and bluish like natural light, and they often create visual conflicts that prevent infinite depth perception when viewed directly.

Innovation Solution

The solution involves a direct-light source with a luminance profile that is uniform across the emitting surface and has a narrow peak in the angular distribution, combined with a diffused-light generator that produces light with a higher Correlated Color Temperature (CCT) to mimic the sky, ensuring that the direct-light component has a lower CCT than the diffused component, and the diffused-light generator is positioned downstream or upstream of the direct-light source to create a coherent visual effect.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single light source is used to generate direct light, then the device structure is simple, but the shadows are not parallel and the visual appearance does not match natural sunlight

Engineering Contradiction:
Improvedevice structureVSAvoidshadow parallelism
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The single light source is segmented into multiple light sources arranged in an array. Each light source emits light in a specific direction, and collectively they produce parallel shadows that match natural sunlight characteristics. This segmentation resolves the contradiction by maintaining relatively simple structure while achieving the precision of parallel shadows.

Inventive Principle:
Principle #1Segmentation

2Volume of moving object

If the light source is positioned at a finite distance, then the device is compact, but the visual appearance does not create infinite depth perception

Engineering Contradiction:
Improvedevice compactnessVSAvoidvisual depth perception
Core Design Contradiction:
Volume of moving objectVSManufacturing precision

Solution Approach 1:

The device creates a virtual image of the light source at infinity through optical design, while the physical light sources remain at finite distances for compactness. This copying of the infinite distance effect resolves the contradiction between compact physical structure and infinite visual depth perception.

Inventive Principle:
Principle #26Copying

3Illumination intensity

If the direct light component has the same CCT as the diffused light, then the lighting is uniform, but it does not match natural sunlight characteristics

Engineering Contradiction:
Improvelight uniformityVSAvoidnatural light replication
Core Design Contradiction:
Illumination intensityVSManufacturing precision

Solution Approach 1:

The direct light component is given a different CCT (lower temperature) than the diffused light component (higher temperature). This local quality differentiation between light components resolves the contradiction by achieving natural sunlight characteristics while maintaining overall lighting effectiveness.

Inventive Principle:
Principle #3Local quality

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

This configuration allows for the creation of shadows that are parallel and bluish, enhancing the visual perception of infinite depth when viewing the illumination device, thereby mimicking natural sunlight and sky conditions effectively.

Implementation Method 1

a diffused-light generator (10) configured to emit a diffused light (35) from a second emitting surface (34), wherein said diffused light (35) is the component of the light which exits the second emitting surface (34) being scattered in virtually all forward directions

Methodology Applied
Scientific EffectScattering: Scattering

Implementation Method 2

a Rayleigh scattering panel 906 placed at a certain distance from the source 902. The panel 906 separates the light rays from the source 902 into a transmitted component 907 with Correlated Color Temperature (CCT) lower than that of the source 902, and into a diffused component 905 with higher CCT, the difference in CCT being due to the fact that the scattering efficiency increases with the inverse of the fourth power of the wavelength in the addressed Rayleigh regime

Methodology Applied
Scientific EffectRayleigh scattering: Rayleigh Scattering

Data Source

PatentEP2920511B2Artificial illumination device for generating natural light
Publication Date: 2023.10.11 COELUX
  • EP2920511B2 patent drawingFigure 1
  • EP2920511B2 patent drawingFigure 2A
  • EP2920511B2 patent drawingFigure 2B

AI summary

An artificial illumination device for generating natural light similar to that from the sun and the sky comprises a direct-light source; and a diffused-light generator, wherein the direct-light source comprises a first light-emitting device configured to emit a primary light, and a first emitting surface (28) positioned downstream of the first light-emitting device, wherein the diffused-light generator is at least partially light-transparent and is positioned downstream of the first light-emitting device and comprises a second emitting surface (34) and is configured to cause diffused light (35) at the second emitting surface (34). The direct-light source produces from the primary light a direct light (236) that exits the first emitting surface (28) with a luminance profile which is uniform across the first emitting surface (28) and has a narrow peak (30) in the angular distribution around a direct-light direction (32). The direct-light source and the diffused-light generator co-operate to form outer light at an outer emitting surface of the artificial illumination device which comprises a first light component which propagates along directions contained within the narrow peak (30) and a second light component which propagates along directions spaced apart from the narrow peak (30), and wherein the first light component (241) has a correlated colour temperature (CCT) which is lower than a CCT of the second light component (243).