Abstract: A method for contactless measurement of the density of a porous material, using a measurement of the refractive index of the material by optical coherence tomography. In the optical coherence tomography technique, the optical path corresponding to the crossing of an object made of the material by a light beam used in the technique, is determined, the thickness of the object is determined, the refractive index of the material is determined from the optical path and from the thickness, and the density of the material is determined from the refractive index.

Abstract: A method for contactless measurement of the density of a porous material, using a measurement of the refractive index of the material by optical coherence tomography. In the optical coherence tomography technique, the optical path corresponding to the crossing of an object made of the material by a light beam used in the technique, is determined, the thickness of the object is determined, the refractive index of the material is determined from the optical path and from the thickness, and the density of the material is determined from the refractive index.

Abstract: According to the invention, to measure an object (32), for example a hollow, translucent or transparent sphere with respect to a visible light, using Snell-Descartes laws, relating to the propagation of light through the object, an equation is established which associates optogeometric parameters of the object with the result of an observation performed directly on an image of the object, said image being acquired by observing said object, by single-view optical shadowgraphy, said image is acquired, the observation is performed, and at least one geometric or optical parameter of the object is determined using the equation and the result of the observation.

Abstract: To measure a hollow three-dimensional object without contact, this object being translucent or transparent vis-á-vis a visible light, an image of the object is acquired by single-view backlit shadowgraphy, along a viewing axis, by observing this object with visible light, this image comprising at least one luminous line, an equation is established that connects at least one optogeometric parameter of the object to at least one geometric parameter of the luminous line, this geometric parameter is determined, and the optogeometric parameter is determined by means of the equation and the geometric parameter thus determined.

Abstract: To measure a hollow three-dimensional object without contact, this object being translucent or transparent vis-á-vis a visible light, an image of the object is acquired by single-view backlit shadowgraphy, along a viewing axis, by observing this object with visible light, this image comprising at least one luminous line, an equation is established that connects at least one optogeometric parameter of the object to at least one geometric parameter of the luminous line, this geometric parameter is determined, and the optogeometric parameter is determined by means of the equation and the geometric parameter thus determined.

Abstract: A motor vehicle has at its front end, a pair of passing or dipped beam headlights and a separate pair of cruising or main beam headlights. The passing headlights and cruising headlights produce, respectively, a regulation, short range, dipped passing beam and a regulation, long range, main or cruising beam. A control unit, when the vehicle is negotiating a bend in passing beam mode, causes at least one of the cruising main beam lights to emit an additional bend beam for lighting into the bend. This bend beam increases the light intensity generally in the direction of the bend.

Abstract: The present invention concerns a lighting device for an automobile, comprising a light source situated at the first focus of a reflector of the elliptical type, a convergent lens being disposed in front of the light source so that the second focus of the elliptical reflector is contained in the object focal plane of the convergent lens, the first and second foci of the elliptical reflector defining an optical axis of the lighting device. According to the present invention, an obscuring element is disposed substantially perpendicular to the optical axis and at a distance from the object focal plane of the convergent lens.

Abstract: A motor vehicle headlight has a reflector with two focal regions, a light source in one of these focal regions producing a pool of reflected light in the other focal region, and a lens which converts the pool of light into a beam projected on the road. The headlight includes means for displacing the light source with respect to the reflector.

Abstract: The present invention concerns a lighting device for an automobile, comprising a light source situated at the first focus of a reflector of the elliptical type, a convergent lens being disposed in front of the light source so that the second focus of the elliptical reflector is contained in the object focal plane of the convergent lens, the first and second foci of the elliptical reflector defining an optical axis of the lighting device.

Abstract: A motor vehicle has at its front end a pair of passing or dipped beam headlights and a separate pair of headlights which are cruising or main beam headlights. The passing lights and cruising lights produce, respectively, a regulation, short range, dipped passing beam and a regulation, long range, main or cruising beam.

Abstract: A motor vehicle headlight has a reflector with two focal regions, a light source in one of these focal regions producing a pool of reflected light in the other focal region, and a lens which converts the pool of light into a beam projected on the road. The headlight includes means for displacing the light source with respect to the reflector.