Artificial lighting system for simulating natural lighting

Patent metadata

Field	Value
Publication number	US-10077884-B2
Application number	US-201313838998-A
Country	US
Kind code	B2
Filing date	Mar 15, 2013
Priority date	Nov 14, 2012
Publication date	Sep 18, 2018
Grant date	Sep 18, 2018

Abstract

A system for illuminating an environment with light that simulates natural light includes: a first light source which emits a beam of visible light; a diffused-light generator delimited by an inner surface, which receives the light beam, and an outer surface, the diffused-light generator being at least partially transparent to a long wavelength component of the beam of visible light. The diffused-light generator transmits diffused light from a short wavelength component of the beam of visible light, through the outer surface, the correlated color temperature of the transmitted light being lower than the CCT of the visible diffused light. The lighting system includes a dark box which hosts the first light source and is optically coupled to the environment via the diffused-light generator.

First claim

The invention claimed is:

1. A lighting system for illuminating an environment with a light that visually simulates sunlight and/or light diffused by one of sunlight and light diffused by the Earth's atmosphere, which comprises:
a first light source configured to emit a beam of visible light;
a diffused-light generator delimited by an inner surface, configured to receive the light beam, and by an outer surface, said diffused-light generator being at least partially transparent to the light beam, being configured to transmit at least part of the light beam, and being further configured to emit, through the outer surface, visible diffused light, the correlated color temperature (CCT) of the transmitted light being lower than the CCT of the visible diffused light; and
a dark box housing the first light source, said dark box being optically coupled to the environment via the diffused-light generator, at least part of said dark box being configured to absorb visible radiation; and
a reflective optical system arranged inside the dark box and configured to convey the light beam onto the diffused-light generator, the first light source and the reflective optical system being configured so that the light beam entirely illuminates the outer surface of the diffused-light generator;
wherein the diffused-light generator is arranged with respect to the first light source so that the relation
|tan(θ 1 −θ 2 )|≤ X ·cos(θ 1 )/ L

holds true for each point of the inner surface spaced apart from a geometric center of the inner surface by X, with X<<L, wherein:
θ 1 is the angle at which a first light ray of the light beam, which originates from the geometric center of an emitting surface of the first light source, impinges on the geometric center of the inner surface;
θ 2 is the angle at which a second light ray, which originates from the geometric center of the emitting surface of the first light source, impinges on said at least one point of the inner surface; and
L is equal to, or greater than, three meters.

2. The lighting system according to claim 1 , wherein the diffused-light generator is such that the CCT of the transmitted light is not greater than the CCT of the light beam.

3. The lighting system according to claim 1 , wherein the diffused-light generator is such that the CCT of the visible diffused light is greater than the CCT of the light beam.

4. The lighting system according to claim 1 , wherein the first light source is configured so that the illuminance across the inner surface varies between a minimum value and a maximum value, the maximum value being not greater than three times the minimum value.

5. A lighting system for illuminating an environment with a light that visually simulates at least one of sunlight and light diffused by the Earth's atmosphere, which comprises:
a first light source configured to emit a beam of visible light;
a diffused-light generator delimited by an inner surface, configured to receive the light beam, and by an outer surface, said diffused-light generator being at least partially transparent to the light beam, being configured to transmit at least part of the light beam, and being further configured to emit through the outer surface, visible diffused light, the correlated color temperature (CCT) of the transmitted light being lower than the CCT of the visible diffused light; and
a dark box housing the first light source, said dark box being optically coupled to the environment via the diffused-light generator, at least part of said dark box being configured to absorb visible radiation; and
a reflective optical system arranged inside the dark box and configured to convey the light beam onto the diffused-light generator, the first light source and the reflective optical system being configured so that the light beam entirely illuminates the outer surface of the diffused-light generator;
wherein the diffused-light generator is arranged with respect to the first light source so that the relation
|(tan(θ 1 −θ e |≤0.5·cos(θ 1 )

holds true, wherein:
θ 1 is the angle at which a first light ray of the light beam, which originates from the geometric center of an emitting surface of the first light source, impinges on the geometric center of the inner surface; and
θ e is the angle at which a second light ray, which originates from the geometric center of the emitting surface of the first light source, impinges on a point of a boundary of the inner surface, said point being the point among the points of the boundary having maximum distance from the geometric center of the inner surface.

6. The lighting system according to claim 1 , wherein the first light source is arranged off-axis with respect to a line perpendicular to the inner surface and passing through the geometric center of the inner surface.

7. A lighting system for illuminating an environment with a
light that visually simulates at least one of sunlight and light diffused by the Earth's atmosphere, which comprises:
a first light source configured to emit a beam of visible light;
a diffused-light generator delimited by an inner surface, configured to receive the light beam, and by an outer surface, said diffused-light generator being at least partially transparent to the light beam, being configured to transmit at least part of the light beam, and being further configured to emit, through the outer surface, visible diffused light, the correlated color temperature (CCT) of the transmitted light being lower than the CCT of the visible diffused light;
a dark box housing the first light source, said dark box being optically coupled to the environment via the diffused-light generator, at least part of said dark box being configured to absorb visible radiation; and
a reflective optical system arranged inside the dark box and configured to convey the light beam onto the inner surface, said reflective optical system being configured so that substantially all light rays emanating, in use, from the inner surface and impinging onto the reflective optical system are not reflected onto the inner surface.

8. The lighting system according to claim 7 , wherein the reflective optical system comprises a first mirror of a plane type.

9. The lighting system according to claim 8 , wherein said first mirror is arranged in parallel to the inner surface, in a manner such that a projection of the first mirror along a plane containing the inner surface does not overlap with the inner surface.

10. The lighting system according to claim 7 , wherein the reflective optical system comprises a first mirror of the converging type.

11. The lighting system according to claim 10 , wherein the first mirror is shaped as a portion of a circular paraboloid.

12. The lighting system according to claim 10 , wherein the first mirror is shaped as a portion of a parabolic cylinder.

13. The lighting system according to claim 12 , wherein the reflective optical system further comprises a second mirror shaped as a portion of a parabolic cylinder, the axes of the first and second mirrors being substantially orthogonal to each other.

14. The lighting system according to claim 13 , wherein the first and second mirrors are arranged so as to share a common focus, the first light source being arranged substantially in the common focus.

15. The lighting system according to claim 7 , wherein the reflective optical system forms a light path connecting the first light source to the inner surface, the first mirror causing a last bend of the light path before the inner surface; and wherein a light ray connecting a be geometric center of the first mirror to a geometric ce

Assignees

• Coelux Srl

Inventors

• Di Trapani Paolo
• Magatti Davide

Classifications

• F21S8/02

  of recess-mounted type, e.g. downlighters (specially adapted for vehicle exteriors F21S41/00-F21S45/00) · CPC title

• E04D2013/0345

  with skylight shafts extending from roof to ceiling · CPC title

• F21V7/0041

  for avoiding direct view of the light source or to prevent dazzling · CPC title

• F21Y2101/00

  Point-like light sources · CPC title

• F21V11/08

  using diaphragms containing one or more apertures · CPC title