Abstract:
A light concentrator is described, for a device for the conversion of solar radiation into electrical, thermal or chemical energy, capable of conveying the radiation towards a surface of the conversion device. The concentrator comprises at least one portion of Fresnel lens of rotational symmetry, one face of which has a plurality of crests disposed concentrically about a centre so as to form a segmented transverse profile of the portion of Fresnel lens. The profile is formed in such a manner that the focal distance of the Fresnel lens is variable in dependence on the radial distance from the centre of the lens. The variation of the focal distance is determined such that, when the Fresnel lens is illuminated by polychromatic radiation, the superposition of the distributions of irradiance, produced by the lens at the individual wavelengths constituting the spectrum of the incident radiation, generates a substantially uniform distribution of polychromatic irradiance on the conversion device.
Abstract:
A reflector for a vehicle headlight is described, capable of illuminating the surrounding space according to a predetermined light distribution. The reflector is formed of a plurality of sectors capable of reflecting the light beam emitted by a light source of the headlight and directing it into predetermined regions of said light distribution. The major part of the sectors of the reflector is delimited at least in part by an edge in which the divergence value of the light beam reflected at said edge portions is constant. The sectors delimited by edge portions having lower values of the angle of spread are arranged to direct the light beam reflected thereby into the regions of the light distribution having a higher spatial gradient of illuminance.
Abstract:
An optical device for motor vehicles, designed to detect the condition of the road surface, comprises a unit for the emission of electromagnetic radiation in the direction of the road surface to be detected, a receiving unit coupled to an optical element for focusing the radiation back-diffused by the road surface and an electronic control and processing unit for receiving signals at output from said receiving unit and for processing them in order to determine the condition of the road surface, on the basis of a reference map. Appearing in said map are the values of the intensity of radiation Iref back-reflected at a reference wavelength and at least one second wavelength. The map is divided into subareas identified beforehand as corresponding to the different conditions of the road surface.
Abstract:
A method of fabrication of transparent LED devices, of the type comprising the operations of: i) providing a series of conductive paths on a transparent underlayer; ii) connecting said conductive paths to electronic control means; iii) associating to said underlayer an array of LED sources addressable individually or in groups through said conductive paths, in which i) said LED sources are integrated in the form of chips, i.e., of elements obtained by dividing up a semiconductor wafer and without package, via technologies of the chip-on-board type; ii) said method envisages the use of the flip-chip technique for die bonding, i.e., the electrical connection of the chip to the underlayer.
Abstract:
Described herein is a transparent device for display of information superimposed on a background, said device comprising a plurality of LED sources, addressable individually or in groups through a series of conductive paths deposited on a transparent underlayer and connected to a control electronics, in which: i) said LED sources are integrated in the form of dice, i.e., of elements obtained by dividing up a semiconductor wafer and without package; and ii) at least one of said conductive paths is with interrupted stretches and replaced by stretches of metal wire, bonded to said paths through a wire-bonding operation.
Abstract:
An emitter (F) for incandescent light sources, in particular a filament, capable of being brought to incandescence by the passage of electric current is obtained in such a way as to have a value of spectral absorption α that is high in the visible region of the spectrum and low in the infrared region of the spectrum, said absorption α being defined as α=1−ρ−τ, where ρ is the spectral reflectance and τ is the spectral transmittance of the emitter.
Abstract:
An optical module for projecting a light beam comprises a solid body of transparent material into which a light source is sunk and which is delimited by an annular surface and by a central surface, and a substantially annular reflecting surface arranged around the solid body. The central and annular surfaces are suitable for receiving respective distinct portions of the luminous flux produced by the source. The reflecting surface may have a reflecting coating or may form part of a transparent body, in which case it works by total internal reflection. The reflecting surface reflects a portion of luminous flux refracted by the annular surface and shapes the flux into a predetermined distribution of luminous intensity about the principal axis. The annular surface is designed in a manner such as to reduce the overall thickness of the module by moving the refracted ray away from the principal axis. The central surface shapes the other portion of the luminous flux emitted by the source into a predetermined distribution of luminous intensity about the principal axis. The surfaces cooperate so as to shape the luminous flux as a whole emerging from the source into a distribution of luminous intensity having divergences which may be different in two directions that are perpendicular to one another and to the principal axis.
Abstract:
A reflector for a vehicle headlight is described, capable of illuminating the surrounding space according to a predetermined light distribution. The reflector is formed of a plurality of sectors capable of reflecting the light beam emitted by a light source of the headlight and directing it into predetermined regions of said light distribution. The major part of the sectors of the reflector is delimited at least in part by an edge in which the divergence value of the light beam reflected at said edge portions is constant. The sectors delimited by edge portions having lower values of the angle of spread are arranged to direct the light beam reflected thereby into the regions of the light distribution having a higher spatial gradient of illuminance.
Abstract:
Described herein is a transparent-display device for motor vehicles, to be used for presentation of information to the driver and/or to the passengers, said device comprising a plurality of LED sources, addressable individually or in groups through a series of conductive paths, deposited on a transparent underlayer and connected to a control electronics, in which: i) said LED sources are integrated in the form of dice, i.e., of elements obtained by dividing up a semiconductor wafer and without package; ii) said dice are integrated on, and electrically connected to, said underlayer via technologies of the chip-on-board type; and iii) said transparent underlayer 1 is pre-arranged for being at least in part superimposed on the windscreen of the vehicle, in such a way that at least part of the information presented to the user is superimposed on the background, said background being visible to the user through said windscreen.
Abstract:
A system for projecting a virtual image within an observer's field of view comprises a support element, a transparent element mounted on the support element and suitable for being placed in front of the observer's eyes, the transparent element comprising a first face and a second face, an image display device suitable for forming an additional image, and a projection and focusing device for projecting the additional image in a manner such as to present it superimposed on the image of the outside world. The display device comprise light-emitting devices disposed on one of the faces of the transparent element, and the projection and focusing device comprise optical elements associated with respective emitting devices and arranged on the other face. Each of the optical elements creates a virtual image of the emitting device associated therewith. The virtual images of the emitting devices together form the additional image.