Abstract: The present invention relates to a backlighting device, having several brightness levels, for a transmission display screen (12). The device comprises light sources placed in a case (14) between a translucent front wall formed by a diffuser screen (20) and a rear wall (24). The light sources, selected according to the desired brightness level, are mosaics (24, 28) of light-emitting diodes (26, 30) that are placed immediately behind the diffuser screen with, for the highest brightness level, a first mosaic (24) of light-emitting diodes that provides daytime illumination and with, for the lowest brightness level, a second mosaic (28) of light sources that supplies night-time illumination.

Abstract: The present invention relates to a backlighting device, having several brightness levels, for a transmission display screen (12). The device comprises light sources placed in a case (14) between a translucent front wall formed by a diffuser screen (20) and a rear wall (24). The light sources, selected according to the desired brightness level, are mosaics (24, 28) of light-emitting diodes (26, 30) that are placed immediately behind the diffuser screen with, for the highest brightness level, a first mosaic (24) of light-emitting diodes that provides daytime illumination and with, for the lowest brightness level, a second mosaic (28) of light sources that supplies night-time illumination.

Abstract: A magneto-optical effect distance measuring device and measuring rig incorporating the device. The device can measure the distance separating two members which can be displaced one with respect to the other by the magneto-optical effect. A permanent magnet is fixed on one of the members and an electro-optical device is fixed on the other member. The electro-optical device includes a diode emitting an optical beam. Further, a Faraday-effect magneto-optical film is disposed, on the one hand, between a polarizer and an analyser and, on the other hand, in the magnetic field of the magnet when the two members are in proximity to one another, the optical beam passing through the assembly. A diode receives the optical beam retransmitted by the analyzer so as to transform the luminous intensity of the beam into an electrical signal whose amplitude depends on the distance separating the two members when they are in proximity to one another.

Abstract: An optical device on board an aircraft for detecting icing conditions including an optical beam emitter to create at least one illuminated external volume of measurement through which there circulates a flow of air charged with water particles; a collector optical system for the collection of at least a part of the light beam back-scattered by the water particles (the external volume of measurement being located on the optical axis of said collector optical system); a photodetector for detecting back-scattered optical beams; a signal processor for processing the signal delivered by the photodetector to compute the severity of the icing conditions; an information provider for providing information on the calculated severity of the icing conditions. Advantageously, the optical means for the differentiation of device includes a differentiation for differentiating between liquid water particles and solid water particles, based on analysis of the polarization.

Abstract: An optical velocimetry probe used in avionics. A measurement volume through which particles can pass is illuminated with a light beam. Light which is backscattered by the particles causes interference with a reference beam which is taken from the original beam. A photodetector detects the interference.

Abstract: A sensor for measuring the concentration of water in liquid phase in a gas moving relative to the sensor. The sensor itself comprises a device for illuminating the water drops transiting a measurement volume, an optical screen, a device imaging the measurement volume onto the optical screen, and photo-detectors to sense the light radiation transmitted by the optical screen.

Abstract: The disclosed device for the analysis of interferometrical sensors of micromovements comprises N light sources, each connected by an optical fiber to a measurement interferometer. Other optical fibers connect the former optical fibers to a single analysis device. The ends of the latter optical fibers are arranged in a circle with a small radius, facing a collimation lens. The output of the analysis interferometer is followed by an optical focusing device and a cell-based detector arranged in a circle.