Abstract: The invention relates to an illumination system for combining two light beams. A prism bounded by two entrance faces that form a dihedron. An integrator is coupled to an exit face of the prism. Each beam penetrates the prism via one of the entrance faces and is reflected by internal reflection on the other entrance face toward the exit face. These beams are substantially focused onto the entrance face of the integrator in such a way that the latter delivers an almost uniform exit beam. Applications: Projection and backprojection apparatus.

Abstract: The invention concerns a polarized light illumination device comprising in particular: a light source, an optical Fresnel Rhomb polarization device receiving light from the source and reflecting it at least twice on at least two opposite surfaces, a reflective polarizer arranged opposite the output surface of the Fresnel Rhomb polarization device to receive the reflected light so as to allow through linearly polarized light along a first direction and to reflect light having any other type of polarization, a reflecting device arranged between the polarization device and the light source so as to allow through the light but to reflect the light reflected by the reflective polarizer. The invention is applicable to liquid crystal display for illuminating liquid crystal valves.

Abstract: The invention relates to an illuminating device comprising an optical source emitting an unpolarized light beam, a polarizing beam splitter comprising a grid polarizer situated between the faces of two prisms. The light beam penetrates into the first prism through a face and reaches the polarizing beam splitter that transmits the light having a first polarization direction to the face that reflects it toward an exit face. In addition, the splitter reflects the light having a second polarization direction to the face that reflects it toward an exit face.

Abstract: A backprojection device is disclosed having an image source, a projection lens, a folding mirror and a projection screen, the image source transmitting an image beam through the projection lens towards the folding mirror, the folding mirror reflecting the beam towards the projection screen. In order to reduce the height of the device beneath the screen, the angle between the surface of the folding mirror and the screen is greater than or equal to 45° and the optical axis of the beam strikes the screen in a zone adjacent to the edge opposite the projection lens, the zone having a height less than or equal to a quarter of the height of the screen.

Abstract: A display device comprises an illumination system that generates a light beam of variable colour along an illumination axis, and an optical motor. The optical motor generates a polarised light beam and comprises a matrix imager, each pixel of which reflects the light beam with a polarization that depends on the image to be generated in the colour received, a first polarization splitter capable of transmitting a polarization of the light beam of variable colour and of at least partly transmitting the beam reflected by the imager in another direction, and a second polarization splitter capable of transmitting the said polarization of the light beam of variable colour.

Abstract: Each optical light extraction element comprises: an entry interface optically coupled with the emissive surface of the cells or that of the substrate of the panel, so as to capture the rays emitted by these cells; an exit interface of suitable shape so that the rays emitted by the cells pass through it; and optionally, a reflective surface that modifies the path of these rays so as to reduce the angle of incidence at this exit interface.

Abstract: The invention concerns a polarized light illumination device comprising in particular: a light source, an optical Fresnel Rhomb polarization device receiving light from the source and reflecting it at least twice on at least two opposite surfaces, a reflective polarizer arranged opposite the output surface of the Fresnel Rhomb polarization device to receive the reflected light so as to allow through linearly polarized light along a first direction and to reflect light having any other type of polarization, a reflecting device arranged between the polarization device and the light source so as to allow through the light but to reflect the light reflected by the reflective polarizer. The invention is applicable to liquid crystal display for illuminating liquid crystal valves.

Abstract: A lighting device for lighting a display surface is provided. The lighting device includes a light source, a lighting well and a lens, which is arranged between the light source and the display surface. Due to the combined use of the lighting well and the lens, light scattered laterally is also reflected in the direction of the display surface.

Abstract: The invention concerns a display apparatus with an imager illuminated by an illumination system and with an imaging system projecting an image on a viewing screen, wherein the brightness of the image on the imager has a variation over a given direction, and wherein the illumination system has means for controlling the light distribution over the given direction.

Abstract: A lighting device for lighting a display surface is described. The lighting device includes a light source, a lighting well and a lens, which is situated between the light source and the display surface. This yields a homogeneous and efficient lighting of a display surface.

Abstract: The present invention relates to a back-lighting system for a transmissive electrooptic modulator using the light polarization effect. The system comprises a means for generating light rays, a reflector for sending the rays back in a direction x and means for guiding the light rays towards the electrooptic modulator, with a reflective linear polarizing film positioned in front of the said means for guiding the light rays. The invention applies to projection.

Abstract: The present invention relates to a backlight system for transmissive electro-optical modulator comprising: at least one source of light rays; at least one reflector for returning the light rays along a first direction referenced z; a means of transmission of light, positioned at the exit of the reflector in such a way as to transport the light rays along the z direction, one of the faces of the transmission means lying along the z direction comprising a micro-prismatic structure which specularly reflects the light rays and extracts them from the transmission means substantially along a second direction referenced x perpendicular to the first direction and a collimation means (20) situated between the source of light rays and the transmission meansz. The said collimation means (20) comprises an entrance face (21) inclined with respect to the first direction referenced z. The invention applies more particularly to retroprojection.