Device for optical-cable transport and combination of light images
First Claim
1. A device for transmitting and combining light images in which a first light image is transported by means of an optical cable formed by an ordered bundle of optical fibers terminating in two flat end faces, an entrance face and an exit face, an entrance lens for forming said first image to be transmitted on the entrance face and an exit lens for transferring the image formed on the exit face in order to permit observation of said image, means being provided for eliminating the raster effect produced by the cable, said eliminating means being constituted by a first optical element upstream of the entrance lens for dispersing the received radiation as a function of the wavelength and a second optical element downstream of the exit lens for inversely combining the emergent radiation and re-forming said first image, said dispersive optical elements being formed by two holographic optical elements, a first holographic element being constituted by a mirror for reflecting a first predetermined spectral band corresponding to said first image, said dispersion being caused by chromatic aberrations exhibited by the first holographic element, the second element being constituted by a partially transparent mirror on the one hand for inversely reflecting the radiation corresponding to said first spectral band and eliminating said aberrations and on the other hand for transmitting the radiation corresponding to a second spectral band which corresponds to a second image to be combined with the first, no wavelength of said first band being contained in said second band.
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Accused Products
Abstract
In a device for optical-cable transport and combination of light images, the ends of an optical cable forming part of the device are coupled with lenses which are in turn associated with an optical system for dispersing radiation as a function of the wavelength in order to suppress any raster effect. This optical system is constituted at one end of the optical cable by a reflecting holographic mirror, the chromatic aberrations of which form the dispersion. At the other end of the cable, the optical system consists of a partially transparent holographic mirror for reflecting a first image to be transported and re-forming this image by suppressing the aberrations and combining said first image with a second image. The first image can be a synthetic image displayed on a CRT indicator and the second image can be the surrounding landscape in an application such as a helmet sight visor.
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Citations
6 Claims
- 1. A device for transmitting and combining light images in which a first light image is transported by means of an optical cable formed by an ordered bundle of optical fibers terminating in two flat end faces, an entrance face and an exit face, an entrance lens for forming said first image to be transmitted on the entrance face and an exit lens for transferring the image formed on the exit face in order to permit observation of said image, means being provided for eliminating the raster effect produced by the cable, said eliminating means being constituted by a first optical element upstream of the entrance lens for dispersing the received radiation as a function of the wavelength and a second optical element downstream of the exit lens for inversely combining the emergent radiation and re-forming said first image, said dispersive optical elements being formed by two holographic optical elements, a first holographic element being constituted by a mirror for reflecting a first predetermined spectral band corresponding to said first image, said dispersion being caused by chromatic aberrations exhibited by the first holographic element, the second element being constituted by a partially transparent mirror on the one hand for inversely reflecting the radiation corresponding to said first spectral band and eliminating said aberrations and on the other hand for transmitting the radiation corresponding to a second spectral band which corresponds to a second image to be combined with the first, no wavelength of said first band being contained in said second band.
Specification