# US 10,371,354 B2 · Illumination device

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- Number: US 10,371,354 B2
- Document ID: US10371354B2
- Status: Granted
- Kind: B2
- Application number: 15/212,675
- Filed: 2016-07-18
- Published: 2017-01-19
- Granted: 2019-08-06
- Earliest claimed: 2008-06-24
- Assignees: CoeLux S.r.l.
- Applicants: CoeLux S.r.l.
- Inventors: Paolo Di Trapani; Marta Cecilia Pigazzini
- Web page: https://patentgrep.com/patent/US10371354B2

## CPC

- F21V 9/02: for simulating daylight (F21V9/04, F21V9/06 take precedence)
- F21V 3/00: Globes; Bowls; Cover glasses (with refracting properties F21V5/00; with reflecting properties F21V7/00; characterised by cooling arrangements F21V29/506)
- F21V 9/08: for producing coloured light, e.g. monochromatic; for reducing intensity of light (with provision for controlling the colour F21V9/40)
- 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)
- F21V 9/40: with provision for controlling spectral properties, e.g. colour, or intensity
- G02B 5/0242: {by means of dispersed particles}
- G02B 6/001: {the light being emitted along at least a portion of the lateral surface of the fibre}
- G02B 6/0041: {provided in the bulk of the light guide}
- G02B 6/0096: {the lights guides being of the hollow type}
- 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)}
- G02B 19/0071: {adapted to illuminate a complete hemisphere or a plane extending 360 degrees around the source}
- G02B 27/30: Collimators
- F21K 9/00: Light sources using semiconductor devices as light-generating elements, e.g. using light-emitting diodes [LED] or lasers
- F21K 9/61: using light guides
- F21S 8/033: {the surface being a wall or like vertical structure, e.g. building facade}
- F21W 2121/00: Use or application of lighting devices or systems for decorative purposes, not provided for in codes F21W2102/00 – F21W2107/00
- F21W 2131/103: of streets or roads
- F21Y 2115/10: Light-emitting diodes [LED]
- F21Y 2115/30: Semiconductor lasers
- H10H 20/851: Wavelength conversion means
- H10H 20/882: {Scattering means (H10H20/82 takes precedence)}
- F21V: FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- F21K: NON-ELECTRIC LIGHT SOURCES USING LUMINESCENCE; LIGHT SOURCES USING ELECTROCHEMILUMINESCENCE; LIGHT SOURCES USING CHARGES OF COMBUSTIBLE MATERIAL; LIGHT SOURCES USING SEMICONDUCTOR DEVICES AS LIGHT-GENERATING ELEMENTS; LIGHT SOURCES NOT OTHERWISE PROVIDED FOR
- F21S: NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
- F21W: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO USES OR APPLICATIONS OF LIGHTING DEVICES OR SYSTEMS
- F21Y: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED
- H10H: INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS

## 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

### Claim 1

An artificial illumination method for reproducing, in an indoor environment, the light and colors of the sun and of the sky, the artificial illumination method comprising:
artificially producing the simultaneous presence of two different color components of visible light, the two different color components comprising:
diffused skylight, wherein blue light is dominant in the skylight; and
directed sunlight having a low blue light component;
wherein artificially producing the simultaneous presence of the skylight and the sunlight comprises producing the skylight and the sunlight in light cones of different angular divergence, wherein the sunlight is directed in a relatively narrow inner cone and the skylight is directed in a relatively wider cone;
wherein the skylight illuminates
a shadow formed by an object with respect to the sunlight, wherein the object is located in the center of the light cone of the sunlight, and
an outer area outside of the light cone of the sunlight, which is not illuminated by the sunlight.

### Claim 2 (depends on 1)

The artificial illumination method of claim 1, wherein
producing the simultaneous presence of skylight and sunlight comprises creating a spectral distribution characteristic of skylight and sunlight.

### Claim 3 (depends on 1)

The artificial illumination method of claim 1, wherein producing the simultaneous presence of two different color components of visible light comprises producing broad-band radiation from a broad-band artificial light source and chromatically diffusing the broad-band radiation to thereby generate the skylight.

### Claim 4 (depends on 3)

The artificial illumination method of claim 3, wherein the broad-band radiation is chromatically diffused such that an area in the environment, for which a direct illumination by the sunlight is prevented by an obstacle, is exposed to the skylight generated by the diffuser, which therefore colors the shadow of the obstacle.

### Claim 5 (depends on 3)

The artificial illumination method of claim 3, wherein the area illuminated by skylight comprises the shadow of an object located in the center of the sunlight cone and an outer area which would not be illuminated by the sunlight cone produced in the absence of chromatically diffusing the broad-band radiation.

### Claim 6 (depends on 3)

The artificial illumination method of claim 3, wherein chromatically diffusing the broad-band radiation is based on a light scattering process in a nanostructured transparent material in “Rayleigh” regime due to which the artificial illumination device is capable of producing a separation and a different distribution between “cold” and “warm” components of light originally produced by the broad-band artificial light source.

### Claim 7 (depends on 6)

The artificial illumination method of claim 6, wherein in the “Rayleigh” regime, the increase of scattering efficiency is inversely proportional to the fourth power of the wavelength.

### Claim 8 (depends on 3)

The artificial illumination method of claim 3, wherein producing the simultaneous presence of two different color components of visible light comprises collimating the broad-band radiation so as to create a cone of given angular divergence as the inner cone, or for reducing the angle of divergence of that radiation.

### Claim 9 (depends on 1)

The artificial illumination method of claim 1, further comprising transforming electrical current into luminous radiation with a visible spectral bandwidth Δλ>100 nm.

### Claim 10 (depends on 9)

The artificial illumination method of claim 9, wherein transforming electrical current into luminous radiation comprises: transforming electrical current into luminous radiation with a visible spectral bandwidth Δλ>170 nm, or transforming electrical current into luminous radiation with a visible spectral bandwidth Δλ>250 nm.

### Claim 11 (depends on 1)

The artificial illumination method of claim 1, wherein the skylight contributes for about 20% to the total luminosity produced by skylight and the sunlight.

### Claim 12

An artificial illumination device for reproducing, in an indoor environment, sunlight and skylight, the artificial illumination device comprising:
a broad-band artificial light source that emits light of broad visible spectrum; and
a chromatic diffuser located downstream of the broad-band artificial light source, wherein the chromatic diffuser is configured to generate the skylight by scattering blue light, which is dominant in skylight, and to generate the sunlight by transmitting the remaining light;
wherein the chromatic diffuser is configured to emit the skylight and the sunlight in light cones of different angular divergence, a narrow inner cone of sunlight and a wider cone of skylight such that the skylight illuminates a shadow formed by an object with respect to the sunlight, the object being located in the center of the light cone of the sunlight, and an outer area outside the light cone of the sunlight, which is not illuminated by the sunlight.

### Claim 13 (depends on 12)

The artificial illumination device of claim 12, wherein the dimension of the chromatic diffuser is selected such that an area in the environment, for which a direct illumination by sunlight is prevented by an obstacle, is exposed to skylight generated by the diffuser, which therefore colors the shadow of the obstacle.

### Claim 14 (depends on 12)

The artificial illumination device of claim 12, wherein the area illuminated by skylight comprises the shadow of an object located in the center of the sunlight cone and an outer area that would not be illuminated by the sunlight cone produced in the absence of the chromatic diffuser.

### Claim 15 (depends on 12)

The artificial illumination device of claim 12, wherein the broad-band artificial light source is configured to transform electrical current into luminous radiation with a visible spectral bandwidth greater than 100 nm.

### Claim 16 (depends on 12)

The artificial illumination device of claim 12, wherein the broad-band artificial light source comprises one or more active elements that either emit photons or absorb photons and then re-emit the photons at a higher wavelength.

### Claim 17 (depends on 12)

The artificial illumination device of claim 12, further comprising a lens configured to collimate the light emitted from the broad-band artificial light source so as to create a cone of given angular divergence as the inner cone, or for reducing the angle of divergence of the light emitted from the broad-band artificial light source.

### Claim 18 (depends on 1)

The artificial illumination method of claim 1, wherein producing the simultaneous presence of two different color components of visible light comprises separating the two different color components of visible light from light having a uniform spectrum.

### Claim 19 (depends on 1)

The artificial illumination method of claim 1, wherein producing the simultaneous presence of skylight and sunlight comprises:
generating skylight by scattering blue light from light of a broad visible spectrum, and
generating sunlight by transmitting the remaining light.

### Claim 20 (depends on 2)

The artificial illumination method of claim 2, wherein the spectral distribution characteristic is given by the light cone of skylight and the light cone of sunlight.

### Claim 21 (depends on 1)

The artificial illumination method of claim 1, wherein producing the simultaneous presence of two different color components of visible light comprises producing the simultaneous presence of two different color components of visible light with a broad-band artificial light source and a nanostructured chromatic diffuser.

### Claim 22 (depends on 1)

The artificial illumination method of claim 1, wherein producing the simultaneous presence of skylight and sunlight comprises producing broad-band radiation by either emitting photons or absorbing photons and then re-emitting the photons at a higher wavelength.