Illumination device

• US 8,622,560 B2
• Filed: 06/19/2009
• Issued: 01/07/2014
• Est. Priority Date: 06/24/2008
• Status: Active Grant

• Current Assignee: CoeLux S.R.L.
• Original Assignee: Light in Light S.r.l.
• Inventors: Di Trapani, Paolo, Pigazzini, Marta Cecilia
• Primary Examiner(s): Mai, Anh
• Assistant Examiner(s): Snyder, Zachary J
• Application Number:
  US13/001,050
• Publication Number:
  US 20110194270A1
• Time in Patent Office: 1,663 Days
• Field of Search: 362/2, 362/147, 362/307
• US Class Current: 362/2
• CPC Class Codes: F21K 9/00 Light sources using semiconductor devices as light-generating elements, e.g. using light-emitting diodes [LED] or lasers
• CPC Class Codes: F21K 9/61 using light guides
• CPC Class Codes: F21S 8/033 the surface being a wall or like vertical structure, e.g. building facade
• CPC Class Codes: F21V 3/00 Globes; Bowls; Cover glasses with refracting properties F21V5/00; with reflecting properties F21V7/00; characterised by cooling arrangements F21V29/506
• CPC Class Codes: F21V 9/02 for simulating daylight F21V9/04, F21V9/06 take precedence
• CPC Class Codes: F21V 9/08 for producing coloured light, e.g. monochromatic; for reducing intensity of light with provision for controlling the colour F21V9/40
• CPC Class Codes: F21V 9/30 Elements containing photoluminescent material distinct from or spaced from the light source shades F21V1/17; globes, bowls or cover glasses F21V3/08, F21V3/12; refractors F21V5/10; reflectors F21V7/26, F21V7/30; elements with provision for controlling the spectral properties or intensity F21V9/40
• CPC Class Codes: F21V 9/40 with provision for controlling spectral properties, e.g. colour, or intensity
• CPC Class Codes: F21W 2121/00 Use or application of lighting devices or systems for decorative purposes, not provided for in codes F21W2102/00 – F21W2107/00
• CPC Class Codes: F21W 2131/103 of streets or roads
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: F21Y 2115/30 Semiconductor lasers
• CPC Class Codes: G02B 19/0047 for use with a light source G02B19/009, G02B19/0095 take precedence; details of lighting devices in general F21V; non-semiconductor lasers having optical devices external to the laser cavity H01S3/005
• CPC Class Codes: G02B 19/0071 adapted to illuminate a complete hemisphere or a plane extending 360 degrees around the source
• CPC Class Codes: G02B 27/30 Collimators
• CPC Class Codes: G02B 5/0242 by means of dispersed particles
• CPC Class Codes: G02B 6/001 the light being emitted along at least a portion of the lateral surface of the fibre
• CPC Class Codes: G02B 6/0041 provided in the bulk of the light guide
• CPC Class Codes: G02B 6/0096 the lights guides being of the hollow type
• CPC Class Codes: H01L 2933/0091 Scattering means in or on the semiconductor body or semiconductor body package H01L33/22 takes precedence
• CPC Class Codes: H01L 33/50 : Wavelength conversion elements

Abstract

An embodiment of an illumination device comprising a broad band artificial light source and a non-liquid chromatic diffuser transparent to visible light comprising a dispersion of elements of nanometrical dimensions of a first material with of certain refractive index in a second material with different refractive index, wherein the light is scattered producing a separation and different distribution between cold and hot components of the light originally produced by the source, according to a scattering process in “Rayleigh” regime. The device allows illumination effects similar to those of natural outdoor environments to be reproduced in indoor environments.

Claims

1. A chromatically non-uniform illumination device comprising:

an artificial light source with a spectral bandwidth of at least 100 nm in the range of wavelengths between 400 nm and 700 nm, the artificial light source comprising one or more active elements which emit photons or which absorb photons and then re-emit photons at a higher wavelength; and

a chromatic diffuser located downstream the artificial light source, which comprises elements of a first non-liquid material transparent to visible light, the elements of the first non-liquid material being dispersed in a second non-liquid material transparent to visible light, the typical linear dimension d of the dispersed elements of the first non-liquid material satisfying the condition 5 nm≦

d≦

300 nm;

wherein the chromatic diffuser is non-absorbent in the range of wavelengths between 400 nm and 700 nm, and a maximum dimension L_max of the chromatic diffuser is equal to or greater than twice a minimum dimension d_min of a projection of the largest of said active elements on a first plane perpendicular to a first direction, wherein said maximum dimension L_max is defined as the greatest between;

a transverse dimension, defined as the maximum distance between couples of points belonging to the projection of the chromatic diffuser on the first plane; and

a longitudinal dimension, defined as the maximum distance between couples of points belonging to the projection of the chromatic diffuser on a second plane parallel to the first direction;

and wherein;

a. in case the artificial light source is anisotropic, said first direction is the maximum emission direction of said artificial light source;

otherwise

b. in case the artificial light source is isotropic, said first direction is defined by a straight line that joins the closest points of said artificial light source and chromatic diffuser.

2. The illumination device according to claim 1, wherein the dispersed elements of the first non-liquid material are solid nanoparticles with refractive index n₁, said second non-liquid material being a solid matrix with refractive index n₂<

n₁.

3. The illumination device according to claim 1, wherein the dispersed elements of the first non-liquid material are gas nanobubbles with refractive index n₁, said second non-liquid material being a solid matrix with refractive index n₂>

n₁.

4. The illumination device according to claim 1, wherein the dispersed elements of the first non-liquid material are nanovolumes of air, said second non-liquid material being formed by a solid dendritic structure of ultra low density silica, comprising clusters of nanoparticles.

5. The illumination device according to claim 1, wherein the chromatic diffuser is a panel having the shape of a parallelepiped, and the artificial light source is arranged on a smallest face of said panel.

6. The illumination device according to claim 1, further comprising a reflector, said artificial light source being arranged inside the reflector so that the reflector is configured to redirect light back-scattered by the chromatic diffuser towards the chromatic diffuser.

7. The illumination device according to claim 1, wherein said chromatic diffuser is structurally separated from said artificial light source.

8. The illumination device according to claim 1, wherein said chromatic diffuser is a panel integrated in a wall of a building.

9. The illumination device according to claim 1, wherein said first non-liquid material has a refractive index n₁, and said second non-liquid material has a refractive index n₂, and wherein |n₂/n₁−

1|>

0.1.

10. The illumination device according to claim 1, wherein the chromatic diffuser is integrated with a lens.

11. A chromatically non-uniform illumination device comprising:

an artificial light source with a spectral bandwidth of at least 100 nm in the range of wavelengths between 400 nm and 700 nm, the artificial light source comprising one or more active elements which emit photons or which absorb photons and then re-emits photons at a higher wavelength; and

a chromatic diffuser located downstream the artificial light source, which comprises elements of a first non-liquid material transparent to visible light, the elements of the first non-liquid material being dispersed in a second non-liquid material transparent to visible light, the typical linear dimension d of the dispersed elements of the first non-liquid material satisfying the condition 5 nm≦

d≦

300 nm;

wherein the chromatic diffuser is non-absorbent in the range of wavelengths between 400 nm and 700 nm, and a transverse dimension of the chromatic diffuser is equal to or greater than twice a minimum dimension d_min of a projection of the largest of said active elements on a first plane perpendicular to a first direction, wherein said transverse dimension is defined as the maximum distance between couples of points belonging to the projection of the chromatic diffuser on the first plane, and wherein;

in ease the artificial light source is anisotropic, said first direction is the maximum emission direction of said artificial light source;

otherwise

in case the artificial light source is isotropic, said first direction is defined by a straight line which joins the closest points of said artificial light source and chromatic diffuser.

12. The illumination device according to claim 11, wherein the transverse dimension of the chromatic diffuser is equal to or greater than ten times the minimum dimension d_min.

13. The illumination device according to claim 11, wherein said first non-liquid material has a refractive index n₁, and said second non-liquid material has a refractive index n₂, and wherein |n₂/n₁−

1|>

0.1.

14. The illumination device according to claim 11, wherein said chromatic diffuser has the shape of a hollow cylinder and said artificial light source has an elongated shape and is positioned coaxially inside said hollow cylinder.

15. The illumination device according to claim 11, wherein the chromatic diffuser is a panel integrated in a wall of a building.

16. The illumination device according to claim 11, wherein said transverse dimension is the maximum dimension of the chromatic diffuser.

17. A chromatically non-uniform illumination device comprising:

an artificial light source with a spectral bandwidth of at least 100 nm in the range of wavelengths between 400 nm and 700 nm, the artificial light source comprising one or more active elements which emit photons or which absorb photons and then re-emits photons at a higher wavelength; and

a chromatic diffuser located downstream the artificial light source, which comprises elements of a first non-liquid material transparent to visible light, the elements of the first non-liquid material being dispersed in a second non-liquid material transparent to visible light, the typical linear dimension d of the dispersed elements of the first non-liquid material satisfying the condition 5 nm≦

d≦

300 nm;

wherein the chromatic diffuser is non-absorbent in the range of wavelengths between 400 nm and 700 nm, and a longitudinal dimension of the chromatic diffuser is equal to or greater than twice a minimum dimension d_min of a projection of the largest of said active elements on a first plane perpendicular to a first direction, wherein said longitudinal dimension is defined as the maximum distance between couples of points belonging to the projection of the chromatic diffuser on the first direction, and wherein;

in case the artificial light source is anisotropic, said first direction is the maximum emission direction of said artificial light source;

otherwise

in case the artificial light source is isotropic, said first direction is defined by a straight line which joins the closest points of said artificial light source and chromatic diffuser;

and wherein said longitudinal dimension is greater than twice a transverse dimension, which is defined as the maximum distance between couples of points belonging to the projection of the chromatic diffuser on the first plane.

18. The illumination device according to claim 17, wherein said longitudinal dimension of the chromatic diffuser is equal to or greater than ten times the minimum dimension d_min.

19. The illumination device according to claim 17, wherein said first non-liquid material has a refractive index n₁, and said second non-liquid material has a refractive index n₂, and wherein |n₂/n₁−

1|>

0.1.

20. The illumination device according to claim 17, wherein the chromatic diffuser has the shape of a hollow cylinder and the artificial light source has a circular crown shape and is arranged coaxially in proximity of one end of said hollow cylinder.