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 center 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 center 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:
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:
Multifunctional optical sensor, comprising a matrix of photodetectors of the CCD or CMOS type, having a sensitive area divided into sub-areas, each of which, individually or combined with others, is dedicated to a specific function of monitoring the scene or measuring environmental parameters. The optical sensor comprises a matrix of microlenses, each of which is set to focus the radiation coming from a portion of solid angle on the associated photodetector or cluster of mutually contiguous photodetectors. Each function is associated to a single microlens or to a single subgroup of mutually contiguous microlenses or to multiple, not mutually contiguous microlenses or to multiple, not mutually contiguous subgroups of microlenses. The angular separation between the central directions of the portions of solid angle subtended by adjacent photodetectors or adjacent clusters of photodetectors is not constant within the matrix.
Abstract:
A light-emitting device comprises a light source in the form of an incandescent filament, a substantial part of which is integrated in a host element having at least one portion structured according to nanometric dimensions. The nano-structured portion is in the form of a photonic crystal or of a Bragg grating for the purpose of obtaining an amplified or increased emission of radiation in the region of the visible.
Abstract:
An optical system for image projection, particularly for projection devices of the “head-mounted”type, includes a display, an optical system for focusing an image formed by the display, and a light guide having an extended body, with two opposite, longitudinal, plane and parallel faces, and opposite ends which define first reflecting surface for coupling into the light guide and second reflecting surface for extracting the image from the light guide. Each light ray which propagates through the light guide undergoes at least three internal total reflections on the parallel plane faces of the light guide. At least a surface of the focusing optical system is a portion of a surface free of rotational symmetry axes. Moreover, the two reflecting surfaces of the light guide are portions of surfaces free of rotational symmetry axes. Finally, the inlet pupil of the light guide coincides with the outlet pupil of the focusing system.
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.
Abstract:
An aircraft which is attachable to, for example, a cellular phone. The aircraft is provided with at least four rotors actuated with compressed fluid or by ring-shaped electric motors.
Abstract:
An illumination arrangement for a vehicle headlight is formed of a plurality of contiguous elementary cells, each including a light source, defined by an emission surface having a horizontal dimension and a vertical dimension and capable of emitting a luminous flux, and an optical system capable of conveying the luminous flux at a predetermined solid angle about a predetermined direction. The elementary cells are disposed so as to generate overall a predetermined distribution of light emission. The horizontal dimension and the vertical dimension of the emission surface of the light sources are different. The vertical dimension is less than 1 mm and the ratio between the horizontal dimension and the vertical dimension is greater than 2.
Abstract:
A lighting device has a light source, comprising a volume (11) inside which combustion of a fuel-comburent mixture is confined. A photonic crystal structure (16) is positioned inside the volume (11). The photonic crystal structure (16) operates to inhibit or limit emission from said passage of at least a part of infrared radiation and simultaneously allow emission of visible light radiation. (FIG. 1)
Abstract:
A light-emitting device comprises a light source in the form of an incandescent filament, a substantial part of which is integrated in a host element having at least one portion structured according to nanometric dimensions. The nano-structured portion is in the form of a photonic crystal or of a Bragg grating, for the purpose of obtaining an amplified or increased emission of radiation in the region of the visible.