Abstract: The present disclosure is directed to a direct-light generator for sun-sky-imitating illumination devices configured for generating natural light similar to that from the sun and the sky The generator includes a first emitting surface and an array of light-emitting devices configured to generate from a primary light a direct light which exits the first emitting surface along a direct-light direction. The direct light exiting the first emitting surface has a luminance profile which has a narrow peak in the angular distribution around the direct-light direction and is uniform across the first emitting surface. Each light-emitting device includes a light emitter having an emitting surface and at least a pair of collimation lenses illuminated by the light emitter.

Abstract: A lighting device includes: a first optical unit and a second optical unit. The first optical unit includes a primary light source and dichroic separation optics. The primary light source is configured to emit primary light in the visible spectrum. The dichroic separation optics are configured to intercept at least part of the primary light generated by the primary light source and emit, from a first emission surface, at least one first highly collimated light component and at least one diffuse light component. The at least one first highly collimated light component and the at least one diffuse light component forms a light with chromatic components having different angular distributions. The second optical unit includes secondary collimation optics is configured to generate, from the light with chromatic component, a weakly collimated light component and a second highly collimated light component.

Abstract: A direct-light generator includes an optical unit positioned downstream of an output surface of a collimated light source and upstream from a first emitting surface with respect to a direct light direction. The optical unit includes a first planar light mixing element characterized by a first response function having a first angular profile with a peak having a first divergence angle, and a second planar light mixing element characterized by a second response function having a second angular profile with a peak having a second divergence angle. The first planar light mixing element at least partially intercepts collimated light exiting the output surface of the collimated light source and defines a unit input surface. The second planar light mixing element is positioned downstream of the unit input surface to at least partially intercept light crossing the unit input surface and to define a unit emitting surface.

Abstract: The present disclosure is directed to an illumination device for providing a divergent illumination. The illumination device comprises a light source for emitting light in a visible spectrum; an output aperture, through which the light emitted from the light source exits the illumination device; and a layer structure. The layer structure comprises a scattering layer of a plurality of nanoscale scattering elements embedded in a host material and is positioned in an optical path of the emitted light that extends between the light source and the output aperture. The layer structure comprises further a pair of areal electrical contact layers, wherein the areal electrical contact layers extend at opposite sides of the scattering layer and are electrically connectable with a power source to generate an electric field across the scattering layer.

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.

Abstract: A sunlight-based projector system (3) is disclosed for providing a direct light beam (5). The projector system (3) comprises a sunlight receiving unit (9) with a collector system (13), a plurality of optical fibers (15), and a plurality of fiber output channels (44). The collector system (13) collects natural outdoor light, and couples the collected light into the plurality of optical fibers (15). The projector system (3) comprises further a sunlight forming unit (11) with a plurality of optical collimator units (47) arranged in a two-dimensional array, wherein each optical collimator unit (47) receives the respective fiber output light (45) and comprises at least one optical collimator (49) for reducing the angular distribution width of the received divergent fiber output light (45). Output areas of the plurality of optical collimator units (47) form essentially a continuously extending large light-emitting face (53) of the sunlight forming unit (11) for emitting an essentially collimated light beam (5).

Abstract: A light source (25) for emitting collimated light (29) in particular for a large area luminaire (21) comprises a light guide unit (43) for guiding light by total internal reflection. The light guide unit comprises a plurality of localized light source regions (57) at a main front face (55A) for having light pass there through. The light source (25) further comprises a plurality of light emitting units (41) for emitting light into the light guide strips (91) through respective portions of the at least one coupling face (47) of the light guide unit (43), and a collimation unit (45) extending along the main front face (55A) and comprising a plurality of collimating elements. At least one light emitting unit (41) is configured as a light input coupling assembly (250) to receive collected natural light from a fiber (249) and to provide the received natural light to the light guide unit (43).

Abstract: An artificial illumination device for generating natural light similar to that from the sun and the sky includes a direct-light source; and a diffused-light generator, wherein the direct-light source includes a first light-emitting device configured to emit a primary light, and a first emitting surface positioned downstream 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 includes a second emitting surface and is configured to cause diffused light at the second emitting surface. Both co-operate to form outer light at an outer emitting surface which includes a first light component which propagates along directions contained within the narrow peak and a second light component which propagates along directions spaced apart from the narrow peak, and wherein the first light component has a CCT which is lower than a CCT of the second light component.

Abstract: A lighting system for illuminating an environment with a lighting that simulates natural lighting, which 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 the light beam. The diffused-light generator transmits at least part of the light beam and emits, through the outer surface, visible diffused light, the correlated color temperature of the transmitted light being lower than the CCT of the visible diffused light. The lighting system includes a dark structure which is optically coupled to the environment via the diffused-light generator and provides a substantially uniform background to the first light source.

Abstract: In an aspect, a moon appearance generating system (1) is configured for providing an enhanced depth perception to imitate a sky scene, for example, a natural sky scene at night.

Abstract: A chromatic stratified panel structure (100) for generating a sun-sky-imitating effect in lighting systems (1) comprises two cover panels (102, 104) at least one of which being a transparent panel; an adhesive transparent polymeric layer (106) sandwiched between the two inner faces of the two cover panels; and at least one nanoparticle-based Rayleigh-like diffusing coating (108) applied to an inner face of at least one of the two cover panels (102, 104) and/or to a face of the adhesive transparent polymeric layer (106) and forming an interlayer between one of the cover panels (102, 104) and the adhesive transparent polymeric layer (106).

Abstract: In an aspect, a lighting system (1) comprises a lighting unit (11) with a light source (31) and a dichroic light exiting surface (15), wherein the lighting unit (11) is configured for emitting dichroic light from the dichroic light exiting surface (15). The emitted dichroic light includes a directional light portion (37) of direct light (17) and a diffused light portion (39) of diffused light (19) with a another larger correlated color temperature. The lighting system further comprises an appearance affecting optical system (13) with a plurality of structural elements (40, 91, 93, 101, 105) that comprise surfaces that delimit a plurality of diffused light passages (14, 103, 107), and comprise direct light illuminated surface regions (25), which are subject to the illumination with direct light (17) from respectively associated affected direct light providing areas (81) of the dichroic light exiting surface (15).

Abstract: In an aspect, a chromatic facade unit for being attached to a wall (1A) of a building (1) is disclosed that can form a facade (3) of the wall (1A). The chromatic facade unit (11) comprises a support structure (15), a chromatic reflective layer (17) formed on the support structure (15), the chromatic reflective layer (17) comprising reflective layer (43) and a chromatic diffusing layer (41), wherein the chromatic diffusing layer (41) is configured to provide for a specular reflectance that is larger in the red than in the blue and for a diffuse reflectance that is larger in the blue than in the red, and the reflective layer (43) is configured to reflect visible light having passed through the chromatic diffusing layer (41).

Abstract: A light source (25) for emitting collimated light (29) in particular for a large area luminaire (21) comprises a light guide unit (43) comprising a plurality of light guide strips (91) configured for guiding light received at the at least one lateral coupling face (47), for example, by total internal reflection. The light guide strips comprise a plurality of localized light source regions (57) at a main front face (55A) for having light pass there through, wherein the light source regions (57) are provided along the light guide strip (91) within a non-source region (59). The light source (25) further comprising a plurality of light emitting units (41) for emitting light into the light guide strips (91) through respective portions of the at least one coupling face (47), and a collimation unit (45) extending along the main front face (55A) and comprising a plurality of collimating elements.

Abstract: A lighting system (1) for in particular forming a room edge (12) of a room comprises an enlarged sky-perception providing unit (2) with a light transparent panel (3) and a mirror unit (13) with a reflective face (13A) forming an inner edge (14), the lighting system further comprises a light source (41) configured to emit a direct light beam (43) through the light transparent panel (3) onto the mirror unit (13) such that the transmitted portion (9) of the light beam is reflected completely by the reflective face (13A), thereby creating a reflected direct light beam (17) in particular for imitating a sun beam.

Abstract: In an aspect, an illumination system (100) includes a light source (102) configured to generate a light beam (103), and a chromatic reflective unit (1) for being illuminated by the light beam (103). The chromatic reflective unit (1) includes a plurality of non-coplanar reflective surface sections (3?), and a chromatic diffusing layer (5) includes a plurality of nanoparticles (37) embedded in a matrix (39). The chromatic diffusing layer (5) is provided upstream of the plurality of reflective surface sections (3?) such that at least a portion of the light beam (103) passes through the chromatic diffusing layer (5) before and after being reflected by the plurality of non-coplanar reflective surface sections (3?). Chromatic diffusing layer (5) is further configured to provide for a specular reflectance that is larger in the red than in the blue and for a diffuse reflectance that is larger in the blue than in the red.

Abstract: A composite system for light diffusion comprises a matrix of a material that is transparent to light; the matrix contains a dispersion of scattering elements having a core that is a nanocluster of inorganic nanoparticles, and a shell comprising silane compounds and dispersing agents; the nanocluster having average dimensions in the range of 20 nm to 300 nm.

Abstract: 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) has a wavelength dependent ensemble light scattering cross-section amount within the visible wavelength range that depends on a relative refractive index between the nanoscale scattering elements (19, 63) and the host material (21, 61) associated to an illumination direction, and an effective size of the nanoscale scattering elements (19, 63) associated to the illumination direction.

Abstract: A lighting system (100A, 100B) comprises a light source (102) for emitting a light beam stripe (220B) with a plurality of light emitting units (603, 803A, 803B) forming an array in the longitudinal direction (X), and an optical element (870) at the exit side of the light source (102) extending across the plurality of light emitting units, and configured to enlarge the beam divergence in the transversal direction.

Abstract: An embodiment of a solid optical sky-sun diffuser, which comprises a transparent solid matrix embedding a dispersion of transparent nanoparticles having an average size d in the range 10 nm?d?240 nm; wherein: the ratio between the blue and red scattering optical densities ??Log [T(450 nm)]/Log [T(630 nm)] of said diffuser falls in the range 5???2.5, where T(?) is the Monochromatic Normalized Collinear Transmittance; in at least one propagation direction, said Monochromatic Normalized Collinear Transmittance is T(450 nm)?0.4; in at least one propagation direction said Monochromatic Normalized Collinear Transmittance is T(450 nm)?0.9, said propagation direction being the same or different from that at which said Monochromatic Normalized Collinear Transmittance is T(450 mm)?0.4.