FR2812090A1 - Color night vision intensifier, has objective image path separator and intensifier with multiple input/output zones and display mechanism visual image recombination forming - Google Patents

Abstract

The image intensifier has a light intensifier (2) with an input (20) and surface image output (23). There is an objective (1) in front of the intensifier. There is a display unit (3) after the intensifier. The input surface has several input zones (21,22) and there are several output zones (24,25). The objective has a unit (10) which separates out different spectral fields. The display mechanism has a recombination unit (30) recombining the light, superimposing the images display to provide a visual image.

Description

The invention relates to the field of color vision systems.

  comprising a light intensifier, and in particular color night vision systems. The intensification of light allows man to observe scenes in very low lighting conditions, allowing him for example to move in an undergrowth at night and

without moonlight.

  Vision systems with a light intensifier are often monochrome vision systems. All the information contained in the different colors of an observation scene is then lost. A color vision system comprising a light intensifier, operating either in true colors or in false colors, makes it possible to store at least part of the information conveyed by color. Since the light intensifier itself is generally not sensitive to color differences, various structures of color vision systems have been adopted in the prior art for

  overcome this particularity of the light intensifier.

  According to a first prior art, there is known a color vision system comprising a light intensifier which successively comprises a photocathode, a microchannel plate, a phosphor screen, and using spatial mosaic filtering. Mosaic filters are used at the photocathode as well as at the screen level. The mosaic filters consist of the regular and periodic juxtaposition of a large number of elementary pixels, each elementary pixel being a point filter filtering only a given color. Each pixel covers an area corresponding to several microchannels. For the mosaic filters to be effective, that is to say so that the colors to be restored are not mixed together or lost, the mosaic filters located at the photocathode must be exactly superimposed on the mosaic filters located at the level phosphor screen; which makes the implementation of these mosaic filters in the system of

  color vision, and therefore the manufacture of it, complex and expensive.

  A disadvantage of the color vision system according to this prior art is that it is complex and expensive. Another drawback of the color vision system according to this prior art is to reduce the resolution by a factor appreciably worth the number of different colors filtered by the mosaic filter, that is to say the number of pixels of a different nature than

includes the mosaic filter.

  According to a second prior art, there is known a color vision system comprising a light intensifier which successively comprises a photocathode, a microchannel plate, a phosphor screen, and using sequential time filtering. Filtered rotating wheels are used at the photocathode as well as at the screen. The filtered wheels consist of the juxtaposition of several equal angular sectors, each angular sector being a simple filter only filtering a given color. Over time, each angular sector of one of the filtered wheels passes successively in front of the photocathode and each angular sector of the other filtered wheel passes successively in front of the phosphor screen. The filtered wheels are then synchronized with each other. A disadvantage of the color vision system according to this prior art is that it is bulky and consumes energy because the filtered wheels have a diameter considerably greater than that of the light intensifier and require a source of energy to ensure their rotation. over time. Another disadvantage of the color vision system according to this prior art is the loss of energy by a factor appreciably worth the number of different colors filtered by the filtered wheel, that is to say the number of angular sectors of nature different than the filtered wheel. One solution, not known in the prior art and not claimed, consists in using several light intensifiers, one for each color or spectral range considered. In all the figures, unless otherwise indicated, the light intensifiers are represented by boxes in which the acronym IL is inscribed. FIG. 1 schematically shows an example of such a solution using red and green filters to obtain by superposition a color image made up of the red and green spectral components. The direction of propagation of the light rays is indicated by the arrows. Elements 300, 308 and 309 are either lenses or lens systems. The elements 302 and 303 are light intensifiers successively comprising a photocathode, a microchannel plate and having the screens 304 and 305 respectively. The element 304 is a red screen while the element 305 is a green screen. Elements 306 and 307 are mirrors. Element 301 is a separating blade separating red and green. Element 310 is a recombinant slide combining red and green. The light arriving on the separating plate 301 is separated into two spectral components, one predominantly red and the other predominantly green. The predominantly red spectral component is intensified, that is to say amplified, through the intensifier 302 and then arrives at the red screen 304 which emits a red light component. The red light component is reflected by the mirror 306 then passes through the optical system 308 before recombining with the green light component at the level of the recombinant plate 310 in order to form a color image downstream of the recombinant plate 310. The component to dominant green is intensified through the intensifier 303 then arrives on the green screen 305 which emits a green light component. The green light component is reflected by the mirror 307 then passes through the optical system 309 before recombining with the red light component at the level of the recombinant plate 310 in order to form a color image downstream of the recombinant plate 310. A drawback of this solution is its cost and its size, given the fact that it requires several light intensifiers, one per spectral component intended to form the final color image, that is to say two light intensifiers in

  the example shown in Figure 1.

  A problem not resolved by the first and second prior art as by the solution described above and not claimed, is to produce a color vision system which includes a light intensifier, this system having little or no drawbacks

  first and second prior art or the unclaimed solution.

  The invention provides a color vision system which comprises a light intensifier, this system being on the one hand simpler and less expensive than the first prior art and on the other hand more compact and less energy consuming than the second prior art. In the color vision system according to the invention, the entry surface of the light intensifier, like the exit surface of the light intensifier, is divided into several spatially distinct zones, each zone being assigned to a different spectral range, separation of zones

  between them is not necessarily materialized.

  According to the invention, there is provided a color vision system comprising, a light intensifier comprising an input image surface and an output image surface, a lens being located upstream of the intensifier and imagining an object field at level of the input image surface of the intensifier, a display device being located downstream of the intensifier and imaging the output image surface of the intensifier, characterized in that the input image surface of the intensifier has several spatially distinct input zones and the intensifier output image surface has several spatially distinct output zones corresponding respectively to the input zones, in that the objective comprises a separation device spectrally filtering and angularly deviating the light so that the objective image respectively at the level of the different input areas different spectral ranges d u same object field, and in that the display device comprises a recombination device spectrally filtering and angularly deflecting the light so that the display device images all the output zones by superimposing them so as to

  form a visual image in color of the object field.

  The invention will be better understood and other features and

  advantages will become apparent from the following description and the drawings

  seals, given as examples, o: - Figure 1 schematically represents an unclaimed solution described above; - Figure 2 shows schematically the main elements that comprise a color vision system according to the invention; - Figure 3 schematically shows a preferred example of sharing in different spatially distinct areas of the input image surface and the output image surface of a light intensifier that comprises a color vision system according to the invention; - Figure 4 schematically shows another preferred example of sharing in different spatially distinct areas of the input image surface and the output image surface of a light intensifier that comprises a color vision system according to the invention; - Figure 5 schematically shows a preferred example of cutting into main structural blocks of a vision system according to the invention comprising an eyepiece; - Figure 6 schematically shows another preferred example of cutting into main structural blocks of a vision system according to the invention comprising a charge coupled sensor; - Figure 7 schematically shows another preferred example of cutting into main structural blocks of a vision system according to the invention comprising a charge coupled sensor integrated in the light intensifier; - Figure 8 schematically shows a first preferred embodiment of a separation device that includes a color vision system according to the invention, based on several prisms; - Figure 9 schematically shows a second preferred embodiment of a separation device that includes a color vision system according to the invention, based on several truncated lenses; - Figure 10 schematically shows a profile view of Figure 9; - Figure 11 schematically shows a third preferred embodiment of a separation device and / or a recombination device that includes a color vision system according to the invention, based on a dichroic blade and several fiber optic networks; - Figure 12 schematically shows a fourth preferred embodiment of a separation device and / or a recombination device that includes a color vision system according to the invention, based on prisms with variable spectral transmission depending light incidence; - Figure 13 schematically shows the variation of the spectral transmission as a function of the light incidence, of certain faces of the prisms used in the system shown in Figure 12; - Figure 14 schematically shows a fifth preferred embodiment of a separation device and / or a recombination device that includes a color vision system according to the invention, based on a blade with non-parallel faces; - Figure 15 schematically shows a sixth preferred embodiment of a separation device and / or a recombination device that includes a color vision system according to the invention, based on dichroic plate and mirrors; FIG. 16 schematically represents a seventh preferred embodiment of a separation device and / or of a recombination device that comprises a color vision system according to

  the invention, based on a dichroic blade and on fiber optic networks.

  FIG. 2 schematically represents the main elements that a color vision system according to the invention comprises. The optical axis a of the vision system is shown in phantom in Figure 2, as in Figures 5 to 7 and 10. The upstream-downstream direction chosen is the direction of propagation of the light beams, which is indicated by arrows placed either on the light beams or outside the light beams for clarity, especially when there are many:

  this agreement remains valid for all figures, unless otherwise stated.

  The color vision system successively comprises from upstream to downstream a lens 1, a light intensifier 2, a display device 3. Objective 1 includes a separation device 10. The

  display device 3 comprises a recombination device 30.

  The light intensifier 2 has an input image surface 20 located at its input and an output image surface 23 located at its output. The input image surface 20 and the output image surface 23 respectively comprise several input and output zones; in Figures 2 and 3, for simplicity and by way of example, only two areas

  are shown for each image surface, but there may be more.

  The input image surface 20 comprises two spatially distinct input zones, the input zones 21 and 22, which can be distinguished for example in upper input zone 21 and lower input zone 22. The image surface of exit 23 has two spatially distinct exit zones, exit zones 24 and 25, which can be distinguished for example in the upper exit zone

  24 and lower exit zone 25.

  The objective 1 image an object field, for example an observation scene, at the level of the input image surface 20. The object field can be broken down into positive, central and negative fields. The intensifier 2 intensifies the image available on its input image surface 20 so as to have an intensified image at its output surface 23. The device 3 for viewing the image of the output image surface 23, therefore l intensified image found there. The exit surface 23 is for example imaged at infinity, the element 40 then representing the exit pupil of the color vision system. The upper 24 and lower exit areas correspond respectively to the upper 21 and lower 22 entry areas, that is to say on the one hand that the image available at the upper entry area 21 is found, intensified, at the upper exit zone 24, and on the other hand that the image available at the lower entry zone 22 is found, intensified, at the level of the

lower outlet 25.

  The separation device 10 spectrally filters the light and deflects it angularly so that the objective 1 image at the level of the respectively upper 21 and lower 22 input areas different spectral ranges of the same object field, for example in FIG. 2 red and green but other spectral ranges can be chosen, a different spectral range per input area. The green spectral range of the object field is imaged on the upper input zone 21 so that an image corresponding to the green spectral content of the object field is found, here for example inverted, on the upper input zone 21. Similarly, the red spectral range of the object field is imaged on the lower input zone 22 so that an image corresponding to the red spectral content of the object field is found, here for example inverted, on the zone of lower entry 22. The image corresponding to the green spectral content of the object field and being located at the upper entry area 21 is intensified, that is to say amplified, to be found at the exit area upper 24. Similarly, the image corresponding to the red spectral content of the object field and being located at the lower input area 22 is intensified, that is to say

  amplified, to find itself at the level of the lower exit zone 25.

  The recombination device 30 spectrally filters the light and deflects it angularly so that the display device 3 images all the exit zones, namely the upper exit zone 24 and the lower exit surface 25, that is to say that is to say the intensified images originating respectively from the upper 24 and lower 25 output zones and corresponding respectively to the green and red spectral contents of the object field and being respectively located at the level of the upper 24 and lower 25 output zones, by superimposing between them these upper 24 and lower 25 output zones, that is to say the images coming from said zones, so as to form a visualized image in color of the object field, each different output zone corresponding to a different spectral range of the image displayed in color, said image representing the object field: for example the green spectral component of the image viewed in co uleur corresponds to the upper output zone 24 while the red spectral component of the image displayed in color corresponds to the lower output zone 25. The image displayed in color is for example imaged at infinity, the element 40 then representing the exit pupil of the color vision system, when the user's eye is intended to be placed downstream of the display device 3. The image displayed in color can also, for example, be imaged on a display image surface represented by the element 40, when a device such as a charge coupled device is intended to be placed downstream of the device 3 of

viewing.

  The image displayed in color was obtained by intensification of each of the red and green spectral components which were respectively restored in red and in green, which is not obligatory, a restitution in false colors can also be carried out. The green and red components of the object field are respectively both separated and sent by the separation device 10 to separate input areas 21 and 22, then are separately intensified by the intensifier 2 so as to end up respectively on distinct output zones 24 and 25, before being respectively at the same time retransformed into green and red components respectively and superimposed between them by the recombination device 30, so as to

  form the image displayed in color.

  For this, each of the separation and recombination devices 10 perform both a spectral light filtering function and an angular light deflection function. The spectral filtering carried out by the separation device 10 is preferably a static optical filtering, consisting for example of colored filters respectively placed in front of the different input zones. The spectral filtering performed by the recombination device 30 depends on the structure of the display device 3, it can be static optics, sequential electro-optics, or even consist of electronic processing in the event of video recovery of the intensified image located at level of the output image surface 23 of the intensifier 2. At the level of the separation device 10 as at the level of the recombination device 30, the angular deviation is preferably carried out by optical elements, examples of which are described later. The separation and recombination devices 10 may consist of several elements located at different locations respectively of the objective 1 and of the viewing device 3. Thus, several spectral components of the object field can be intensified separately by a single light intensifier 2. The decomposition of the input 20 and output 23 image areas of the intensifier 2 into several zones leads to a compromise between the extent of the object field observed and the resolution with which this object field is observed. For example, when cutting the input image surface 20 into two input zones 21 and 22, either the resolution is divided by a factor of two, or the extent of the observed field is divided by a factor of two, or the resolution and the extent of the field are respectively divided by factors between one and two. In observation applications in particular, a flattened vertical field, that is to say for which the vertical resolution has been divided by a factor of two, is not very troublesome. The light intensifier is preferably a light intensification tube comprising successively from upstream to downstream the following elements, namely an inlet blade for sealing the tube, a photocathode deposited on the blade input, the role of the photocathode being to transform the photons received into electrons, a system of transfer and multiplication of electrons with microchannels of the type of a microchannel plate, a phosphor screen deposited on an output blade, the role of the phosphor screen is to transform the electrons received into photons, the output plate for sealing the tube. Without any particular structure of the vision system, during the transformation of photons into electrons at the photocathode, the information conveyed by the wavelength of photons, that is to say the colors contained in the object field, is lost. The particular structure of the color vision system according to the invention as described above is particularly advantageous because at least part of the information conveyed by the colors of the object field is retained, that is to say that the information contained in the colors of the object field is not completely lost. In addition, this structure can allow the use of existing light intensifiers without having to make any modifications to them, or at least without having to

make major changes.

  Preferably, the input image surface of the intensifier consists of two to four input zones. The input image surface of the intensifier advantageously consists of two input zones, as in FIG. 3 for example. FIG. 3 schematically represents a preferred example of partitioning into two spatially distinct input zones of the input image surface and of the output image surface of a light intensifier that a color vision system according to the invention comprises . The disc represents in one case the input image surface 20 of the intensifier 2 and in the other case the output image surface 23 of the intensifier 2. The upper rectangle represents either the upper input area 21 or the upper exit area 24. The lower rectangle represents either the lower entry area 22 or the exit area

lower 25.

  Preferably, all the entry zones are identical, that is to say

  say have the same area and the same shape. Figure 3 shows the example of rectangular shapes of entry areas. FIG. 4 schematically represents another preferred example of partitioning into two spatially distinct zones of the input image surface and the output image surface of a light intensifier that a vision system comprises.

in color according to the invention.

  In FIG. 4, the input image surface 20 of the intensifier 2 and the output image surface 23 of the intensifier 2 are circular and can be broken down into two semicircles respectively upper cs and lower ci which are separated by a diameter d of the complete circle c. The upper 21 and lower 22 input zones and / or the upper 24 and lower 25 output zones each have a rectangle inscribed in the assembly consisting on the one hand by a semicircle of the input image surface 20 and / or of the output image surface 23 and on the other hand by the diameter d which underlies said semicircle, the two rectangles having a large common side which is a portion of the diameter d. In practice, the two rectangles are separated by a neutral zone of small thickness. The

  upper entry 21 and / or exit 24 areas are included in the half

  upper circle cs and include the upper rectangle rs while the

  lower entry 22 and / or exit 25 areas are included in the half

  lower circle ci and include the lower rectangle ri.

  On the side of each of the short sides pc of each rectangle, the zone corresponding to the rectangle is extended by an additional sad surface delimited by two arcs of circle, one of which follows the contour of the image surface, the layout of the arcs of circle being arranged in such a way that one of the zones is the transform of the other by a translation of direction perpendicular to that of the large common side, that is to say of the

  diameter d, and of length equal to that of a small side pc of rectangle.

  By way of example, the additional sad surface situated to the left of the upper rectangle rs is delimited by the arcs of acl acl and ac2 as well as by the small left pc side of the upper rectangle rs. The upper zone, inlet 21 and / or outlet 24, consists of the rectangle

  upper rs and two additional sad surfaces located in the half

  upper circle cs while the lower zone, entry 22 and / or exit, consists of the lower rectangle ri and the two surfaces

  additional sad located in the lower semicircle ci.

  Thus, in FIG. 4, the surface of the entry and / or exit zones is increased compared to the case of FIG. 3, for a given format of

  rectangle, and the entry and / or exit areas remain identical to each other.

  In FIG. 3, the entry and / or exit zones are preferably either all 16/9 format rectangles or all

4/3 format rectangles.

  Each of the input zones corresponds to a spectral range of the object field. Each of the exit zones corresponds to a component

  spectral image viewed in color.

  In vision systems according to the prior art comprising a light intensification tube comprising a microchannel plate, this causes a loss of information on the nature which is seen by a user of the vision system, this loss coming from the loss of information conveyed by the different colors represented in the object field. For example, such a vision system may not show any

  difference between a field of grass and a land of land.

  The vision system according to the invention can make it possible to solve this problem at least to a certain extent because it makes it possible to conserve part of the information conveyed by the colors contained in the object field, since at least two spectral ranges of the field

  object are intensified separately.

  Although the spectral response of the light-intensifying tubes does not entirely correspond to that of the eye, with a judicious choice of the spectral ranges considered upstream of the light-intensifying tube and the spectral components considered downstream of the light tube intensification of light, a restitution close to the effective perception of the eye in the visible can be obtained. The choice of upstream spectral ranges and downstream spectral components can take into account the high reflectivity of chlorophyll in the near infrared, thus making it possible to restore a chromatic contrast of a scene presenting for example an alternation of plant elements and

  minerals which is close to the effective perception of the eye in the visible.

  This also helps to distinguish between certain camouflages based on green paint and greenery, because greenery and green paint often do not

  not the same reflectivity in the near infrared.

  Preferably, the spectral ranges of the two input zones are respectively the visible and the near infrared. For example, the visible range is approximately between 450nm and 700nm. For example, the

  near infrared is approximately between 700nm and 900nm.

  Advantageously, the output zone corresponding to the visible spectral range is restored by the display device 3 in red color and the output zone corresponding to the near infrared spectral range is restored by the display device 3 in green color. This type of display is called in false colors because the spectral components of the image displayed in color are completely different from the spectral ranges to which they correspond. It is also possible to produce a vision system allowing visualization in true colors, it suffices then that the visible and near infrared spectral ranges which were respectively restored in red and green components, become respectively red and green spectral ranges. An advantage of viewing in false colors here is to consider a spectrum wider than that of the visible and therefore to collect more light than in the case of viewing in true colors. In a visualization in true colors, the overall gain of the vision system would be reduced by the decrease in the extent of the light spectrum arriving on the

  input image area 20 of intensifier 2.

  The display device 3 preferably comprises an eyepiece located downstream of all the other optical elements of the system. FIG. 5 schematically represents a preferred example of cutting into main structural blocks of a vision system according to the invention comprising an eyepiece. The vision system successively comprises from upstream to downstream a lens 1, a light intensifier 2, an eyepiece 8 downstream of which can be placed the eye 4 of the user of the vision system. The viewing device 3 is then constituted by the eyepiece 8. The object field is focused by the objective 1 on the input image surface 20 so that several images of the object field are on the one hand at the level of the input image surface 20 and on the other hand intensified at the level

of the output image surface 23.

  The display device 3 advantageously comprises an image transport not shown in FIG. 5 and located between the intensifier 2 and the eyepiece 8. The display device 3 also preferably comprises at least one charge coupled device and a screen , successively located between the image transport and the eyepiece. FIG. 6 schematically represents a preferred example of cutting into main structural blocks of a vision system according to the invention comprising a charge coupled device. The vision system successively comprises from upstream to downstream a lens 1, a light intensifier 2, an image transport 5, at least one device 6 with charge coupling, a screen 7. The curved arrow line between the device

  6 with charge coupling and the screen 7 represents an electrical connection.

  Screen 7 allows the visualization of the image viewed in color; if the screen 7 is small, an eyepiece 8 can be placed downstream of the screen 7, the eyepiece 8 then being secured to the screen 7. The display device 3 is constituted by the transport 5 of image, the charge coupled device 6, the screen 7, as well as by the eyepiece 8 if necessary. The object field is focused by the objective 1 on the input image surface 20 so that several images of the object field are on the one hand at the level of the input image surface 20 and on the other hand intensified. at the level of the output image surface 23. These images available on the output image surface 23 are taken up by the image transport 5 in order to be focused, separately or superimposed between themselves as the case may be, on the sensitive surface 60 of the device 6 with charge coupling, before ending up at the level of the screen 7. The images are recombined advantageously, either optically upstream of the sensitive surface 60 when the images are focused while being superimposed on the sensitive surface 60 , either electronically in the charge coupled device 6 when the images are focused separately on the sensitive surface 60, or even electronically downstream of the charge coupled device 6 when the images are focused separately on the sensitive surface 60. The screen 7 is

  for example a color cathode ray tube.

  The display device 3 preferably comprises a charge coupling device integrated into the intensifier and located downstream of the output image surface, and a screen located downstream of the intensifier. FIG. 7 schematically represents a preferred example of cutting into main structural blocks of a vision system according to the invention comprising a charge coupled device integrated into the light intensifier. The vision system successively comprises from upstream to downstream a lens 1, a light intensifier 2, a device 6 with charge coupling, a screen 7. The curved line arrow between the device 6 to

  charge coupling and screen 7 represents an electrical connection.

  Screen 7 allows the visualization of the image viewed in color; if the screen 7 is small, an eyepiece 8 can be placed downstream of the screen 7. The charge coupling device 6 is physically integrated into the light intensifier 2, that is to say that in the case of a conventional light intensifier 2 with a microchannel plate, the electrons leaving the microchannels, instead of being transformed into photons, are directly stored in the device 6 with charge coupling: for the intensifier 2 of light, instead of talking about IL, we talk about ILCCD. The display device 3 is functionally constituted by the charge coupling device 6, the screen 7, as well as by the eyepiece 8 if necessary. The object field is focused by the objective 1 on the input image surface 20 so that several images of the object field are at the level of the input image surface 20. These images are found intensified at the level of the input of the coupling device 6 before ending up at the screen 7. The screen 7 is for example a color cathode ray tube. The recombination of the images is advantageously carried out electronically in the device 6 with coupling

dump.

  For all vision systems according to the invention comprising a charge coupled device, several variants of devices 6 to

  charge coupling are available.

  A first variant consists of a charge coupled device 6 on the one hand having a sensitive surface 60 which comprises several useful zones corresponding respectively to the output zones of the output image surface 23 of the intensifier 2 and on the other hand being oriented so that the height of the object field is imaged on the large

  dimension of the sensitive surface 60 of the charge coupled device 6.

  The orientation of the charge coupled device 6 is then offset by 90

  relative to the normal orientation of such a charge coupled device 6.

  The charge coupled device 6 is preferably at high resolution.

  A second variant consists of a device 6 with color charge coupling, the recombination device 30 then being entirely optical and located upstream of the device 6 with charge coupling. The image displayed in color is already present on the sensitive surface 60 of the

charge coupled device 6.

  In a third variant, the display device 3 comprises several charge coupling devices 6 all located upstream of the recombination device 30, the sensitive surfaces 60 of the charge coupling devices 6 corresponding respectively to the exit zones of

  the output image surface 23 of the intensifier 2.

  Whatever the variant using only one charge coupled device 6, to fully use the size of the sensitive surface 60 of the charge coupled device 6, an anamorphosis, that is to say vertical compression, is advantageously introduced into the objective 1 and / or into the image transport 5 so as to adapt the format of the output image surface 23 of the intensifier 2 to the format of the sensitive surface 60

  of the charge coupled device 6.

  Whatever the variant using one or more devices 6 with charge coupling, but not using a device 6 with color charge coupling, the recombination device 30 is advantageously constituted by entirely electronic processing means. The different images of the object field being still separated on the sensitive surface 60 of the device (s) 6 with charge coupling, they are recombined in or downstream of the device (s) 6 with coupling, for example using a memory d 'picture. The functions of both spectral filtering and angular deviation of the recombination device are here performed in a manner

fully electronic.

  The various preferred embodiments of the separation devices 10 and / or of the recombination devices that a color vision system according to the invention may include will now be described in more detail. They can be broken down into two categories, the first category in which the objective is formed by several pupil portions and the second category in which the objective is formed by a single pupil. The first category includes the first two embodiments and can only apply to the separation device 10, unless the recombination device 30 includes a charge coupling device 6. The second category includes the last five embodiments and can be applied to the separation device 10 as well as to the recombination device 30. It is possible to use respectively for the separation device and for the recombination device of the same color vision system, either the same embodiments, or

different embodiments.

  In the first and second embodiments of the separation device, the entrance pupil of the objective 1 is formed of several pupil portions, the pupil portions corresponding respectively to the entry zones. In FIGS. 8 to 10, only two half-pupils are shown, but the entrance pupil of the objective can be broken down into

  more pupil portions.

  The angular deflection of the light in the separation device 10 is preferably carried out by several adjoining prisms, the prisms corresponding respectively to the pupil portions. FIG. 8 schematically represents a first preferred embodiment of a separation device that comprises a color vision system according to the invention, based on several prisms. The separation device 10 comprises two prisms 101 and 102 which are placed side by side. Each of the prisms 101 and 102 corresponds to a half-pupil; in FIG. 8, the upper prism 101 corresponds to the upper half-pupil while the lower prism 102 corresponds to the lower half-pupil. Downstream of the separation device 10 is located an optical system 9 composed for example of one or more lenses and belonging to the objective 1. Downstream of the objective 1 is located the light intensifier 2. The upper half of the light beams, represented by a simple arrow, arrives on the upper prism 101 to then be focused by the lens 1 on the upper entry area 21. The lower half of the light beams, represented by a double arrow, arrives on the lower prism 102 to then be focused by the objective 1 on the lower entry zone 22. Preferably, thin filtering layers are deposited on the prisms 101 and 102,

  advantageously on the face on which the light beams arrive.

  Each of these layers corresponds to a spectral range corresponding to one of the input zones: thus on each input zone is focused only one spectral range of the object field. For example, a near infrared filter is placed at the upper prism 101 while a visible filter is placed at the lower prism 102. Thus the near infrared spectral range of the object field is focused on the upper input area 21 while that the visible spectral range of the object field is focused on the lower input area 22. In the separation device 10, the angular deviation function is performed by the prisms 101 and 102 while the spectral filtering function is performed by the layers

  thin filters deposited on these same prisms.

  The angular deflection of the light in the separation device 10 is preferably carried out by several joined truncated lenses situated in the same plane and linked together by their truncated part. FIG. 9 schematically represents a second preferred embodiment of a separation device 10 that comprises a color vision system according to the invention, based on several lenses

  truncated. The entrance pupil of objective 1 is formed by two half

  pupils, each of the half pupils corresponding to a truncated lens.

  The upper and lower half-pupils correspond respectively to the

  upper 103 and lower 104 truncated lenses.

  The offset, in a plane orthogonal to the direction of propagation of light, existing between the focal points of the truncated lenses is preferably equal to the offset existing between the centers of the corresponding entry zones. FIG. 10 schematically represents a profile view of FIG. 9. The center Is of the upper truncated lens 103 and the center li of the lower truncated lens 104 are offset by a distance d which is equal to the distance separating the center zs of the area

  upper entry 203 of the center zi of the lower entry area 204.

  The optical axis a of the vision system is located at mid-distance as well from

  Is and li centers as zs and zi centers.

  The upper half of the light beams, represented by a simple arrow, arrives on the upper truncated lens 103 in order then to be focused by the upper truncated lens 103 on the upper entry zone 203. The lower half of the light beams, represented by an arrow double, arrives on the lower truncated lens 104 to then be focused by the lower truncated lens 104 on the lower entry zone 204. Preferably, thin filtering layers are deposited on the truncated lenses 103 and 104, advantageously on the face on which the light beams arrive. Each of these layers corresponds to a spectral range corresponding to one of the input zones: thus on each input zone is focused only one spectral range of the object field. For example, a near infrared filter is placed at the upper truncated lens 103 while a visible filter is placed at the lower truncated lens 104. Thus the near infrared spectral range is focused on the upper input area 203 while the visible spectral range is focused on the lower entry zone 204. In the separation device 10, the angular deviation function is carried out by the truncated lenses 103 and 104 while the spectral filtering function is carried out by the thin filtering layers deposited on these same truncated lenses. The embodiments of the second category have

  preferably a single pupil. They will now be described in more detail.

  All these embodiments can be applied either to the device 10

  separation, or to the recombination device, unless otherwise stated.

  The direction of propagation of the light beams in FIGS. 11, 12 and 14 to 16 corresponds to the arrow in solid lines if we consider that the embodiment is applied to the separation device 10 and to the arrow in dotted lines if it is considered that the embodiment is applied to the recombination device. In FIGS. 11, 12 and 14 to 16, only two input and / or output zones are represented on the image 20 input and / or output 23 surface of the light intensifier 2, but these surfaces d entry and / or exit may have a larger number

entry and / or exit zones.

  The spectral filtering and the angular deflection of the light in the separation device 10 and / or in the recombination device 30 are preferably carried out by a dichroic blade 105 and by two networks of optical fibers, respectively the upper network 106 of optical fibers and the lower network 107 of optical fibers. The dichroic blade 105 can of course be replaced by an equivalent element, such as for example by a separator cube. The optical fiber networks 106 and 107 are located upstream of the input image surface 20 and / or downstream of the output image surface 23 and are physically integrated into the light intensifier 2 although functionally considered to belong to the device 3 display. The inlet and / or outlet faces 206 and 207 respectively of the upper 106 and lower 107 networks are arranged orthogonally to one another. FIG. 11 schematically represents a third preferred embodiment of a separation device 10 and / or of a recombination device that comprises a color vision system according to the invention, based on a dichroic blade and several fiber optic networks. In the case of the separation device 10, the dichroic blade 105 makes it possible to separate the spectral ranges of the object field corresponding respectively to the different input zones. Indeed, the light beams pass through the optical system 9, arrive on the dichroic plate 105 which separates them in the upper half of the light beams focusing on the entry face 206 of the upper network 106 of optical fibers and in the lower half of the light beams focusing on the input face 207 of the lower network 107 of optical fibers. The upper 106 and lower 107 networks respectively guide the upper and lower halves of light beams so that these arrive respectively at the upper 21 and lower 22 entry zones.

of the input image area 20.

  In the case of the recombination device 30, the dichroic slide 105 makes it possible to recombine the different images respectively from the different output zones by superimposing them so as to

  form the image displayed in color, an image which represents the object field.

  The intensified images of the object field are available respectively on the upper 24 and lower 25 output areas of the output image surface 23. These intensified images are respectively guided by the upper 106 and lower 107 networks so as to arrive respectively at their level. upper 206 and lower 207. exit face. These intensified images are recombined and filtered by the dichroic plate 105 so as to be superimposed between each other, each intensified image constituting one of the spectral components of the image displayed in color available downstream of the optical system 9: for example, one of the intensified images forms the green spectral component of the image viewed in color while the other intensified image forms its red spectral component. The spectral filtering and the angular deflection of the light in the separation device 10 and / or in the recombination device 30 are preferably carried out by two prisms which are arranged head to tail and on which the spectral transmission of at least certain faces depends of the incidence of light. FIG. 12 schematically represents a fourth preferred embodiment of a separation device 10 and / or of a recombination device that comprises a color vision system according to the invention, based on transmission prisms

  spectral variable depending on the light incidence.

  In the case of the separation device 10, from upstream to downstream the vision system successively comprises the separation device 10 consisting of two prisms 108 and 109 arranged head to tail, an optical system 9, the entry zones respectively upper 21 and lower 22 of the input image surface 20 of the light intensifier 2. Objective 1 includes the separation device 10 and the optical system 9. From upstream to downstream, are successively located the upstream face 110 of the prism 108, then the common face 111 between the prisms 108 and 109, and then the downstream face 112 of the prism 109. One of the spectral ranges of the object field, for

  example visible, successively crosses the three faces 110, 111 and 112.

  The other spectral range of the object field, for example the near infrared, crosses the upstream face 110, then crosses the common face 111, then is reflected on the downstream face 112, then is again reflected on the common face 111, then crosses the downstream face 112 to be downstream of the separation device 10. The spectral transmission of the common 111 and downstream 112 faces depends on the incidence of the light beams. An example of this dependence is represented in FIG. 13. FIG. 13 diagrammatically represents the variation of the spectral transmission as a function of the light incidence, of certain faces of the prisms used in the system represented in FIG. 12, here for example of the downstream face 112. The abscissa axis represents the wavelength X while the ordinate axis represents the transmission T in percentage%. The curve C1 in solid lines represents the variation of the spectral transmission for a low light incidence, for example ranging from 0 to 10, while the curve C2 in dotted lines represents the variation of the spectral transmission for a medium light incidence, for example ranging from 12 to 22. This type of filtering is based on an offset of the fronts fr as a function of the light incidence. The curves C 1 and C 2, with perfectly abrupt fronts fr, represent an ideal case. When it arrives at the downstream face 112, the visible spectral range between for example 450nm and 700nm arrives with a low light incidence and therefore crosses the downstream face 112, which corresponds to a transmission T equal to 100%. On its first arrival at the downstream face 1 12, the near infrared spectral range for example between 700nm and 900nm arrives with a low light incidence and therefore is reflected on the downstream face 112, which corresponds to a transmission worth 0 %. On its second arrival at the downstream face 112, the near infrared spectral range arrives with an average light incidence and therefore crosses the downstream face 112, which corresponds to a transmission worth 100%. The common face 111 can be produced in a similar manner. The near infrared and visible spectral ranges have not undergone the same number of reflections in prisms 108 and 109, and the light beams composing them do not exit with the same angle of the prism 109. The light beams composing the near infrared spectral range will for example be focused on the upper entry area 21 while the light beams composing the visible spectral range will for example be focused on the entry area

lower 22.

  In the case of the recombination device 30, each intensified image is available at an output zone. The spectral component, for example green, of the intensified image coming from the upper output zone 24 and the spectral component, for example red, of the intensified image originating from the lower output zone 25 will be superimposed between them after they have passed through the two prisms. joined 109 and 108, so as to form the image displayed in color after having left

of the prism 108 by the face 110.

  The spectral filtering and the angular deflection of the light in the separation device 10 and / or in the recombination device 30 are preferably carried out by a blade with non-parallel faces whose upstream face is a spectral filter while the downstream face is a mirror, the reflecting side of which is arranged towards the inside of the blade. FIG. 14 schematically represents a fifth preferred embodiment of a separation device 10 and / or of a recombination device that comprises a color vision system according to the invention, based on a slide

with non-parallel faces.

  In the case of the separation device 10, the light beams first arrive on the upstream face 114. The upstream face 114 is a filter letting pass one of the spectral ranges, for example the near infrared, and reflecting the other, for example the visible, while the downstream face 113 is a mirror on the inside of the plate 10. The near infrared spectral range passes through the upstream face 114, is reflected from the inside of the downstream face 113, passes through the upstream face 114 to be focused on the upper input area 21 after passing through the optical system 9. The visible spectral range is reflected on the upstream face 114 which is not parallel to the downstream face 113, the visible spectral range is then focused on the area

  lower entry 22 after passing through the optical system 9.

  In the case of the recombination device 30, the light beams of each intensified image exit respectively from the upper 24 and lower 25 exit zones, pass through the optical system 9 and arrive first on the upstream face 114. The upstream face 114 is a filter letting through one of the spectral components which will constitute the image displayed in color, for example green, and reflecting the other, for example red, while the downstream face 113 is a mirror on the side of the interior of the plate 10. The green spectral component of the intensified image coming from the upper exit zone 24 crosses the upstream face 114, is reflected from the inside of the downstream face 113, crosses again the upstream face 114 to be superimposed with the spectral component red which is reflected on the upstream face 114 which is not parallel to the downstream face 113. The superposition of the green spectral component of the intensified image coming from the fate zone ie upper 24 and the red spectral component of the intensified image coming from the exit zone

  lower 25 constitutes the image viewed in color.

  The spectral filtering and the angular deflection of the light in the separation device 10 and / or in the recombination device 30 are preferably carried out by at least one dichroic blade and several mirrors. FIG. 15 schematically represents a sixth preferred embodiment of a separation device 10 and / or of a recombination device that comprises a color vision system according to

  the invention, based on a dichroic blade and mirrors.

  In the case of the separation device 10, the dichroic blade 115 makes it possible to separate the spectral ranges of the object field corresponding respectively to the different input zones. Indeed, the light beams pass through the optical system 9, arrive on the dichroic plate 115 which separates them in the upper half of the light beams focusing on the upper entry area 21 after having been successively reflected by the mirrors 116 and 117 and lower half of the light beams focusing on the lower entry area 22 after being

reflected by the mirror 118.

  In the case of the recombination device 30, the dichroic blade makes it possible to recombine the different images respectively from the different output zones by superimposing them so as to form the image displayed in color which represents the object field. The intensified images of the object field are available respectively on the upper 24 and lower 25 output areas. These intensified images are respectively reflected one by the mirrors 117 and 116 and the other by the mirror 118 so as to each arrive at 'a different side of the dichroic plate 115. These intensified images are recombined and filtered by the dichroic plate 105 so as to be superimposed between each other, each intensified image constituting one of the spectral components of the image displayed in color available downstream of the optical system 9: for example, the intensified image coming from the upper exit zone 24 has its reflected red component and its transmitted green component which alone forms the green spectral component of the image displayed in color after having passed through the optical system 9 while the intensified image from the lower exit zone 25 has its transmitting green component ise and its reflected red component which alone forms the red spectral component

  of the image displayed in color after having passed through the optical system 9.

  In a variant of the sixth embodiment, the angular deflection of the light in the recombination device is achieved by at least one semi-reflecting plate and several mirrors, the semi-reflecting plate and the mirrors being arranged so as to add a channel. additional optics for binocular vision. The dichroic plate of FIG. 15 is replaced by a separating plate while two filters corresponding for example to the green and red spectral components are added between the exit zones and the separating plate 115. The green filter is for example placed between the zone of upper outlet 24 and the mirror 117. The red filter is for example placed between the lower outlet area 25 and the mirror 118. In the direction D shown in the figure, another optical system 9 not shown allows an additional optical channel forming a second image displayed in identical color

  to the first, thus allowing binocular vision.

  The spectral filtering and the angular deflection of the light in the separation device 10 and / or in the recombination device 30 are carried out by at least one dichroic blade 119, two networks 121 and 122 of optical fibers, respectively the upper network 121 and the lower network 122, and a mirror 120 located between the dichroic blade 119 and the upper network 121 of optical fibers. The upper 121 and lower 122 networks are arranged parallel to each other. The upper network 121 is longer than the lower network 122, so as to take account of the additional optical path traveled between the dichroic plate 119 and the mirror by the upper half of the light beams arriving on the upper network 121. The upper networks 121 and lower 122 are located upstream of the input image surface 20 and / or downstream of the output image surface 23 and are physically integrated into the light intensifier 2 although functionally considered as belonging to the display device 3. FIG. 16 schematically represents a seventh preferred embodiment of a separation device 10 and / or of a recombination device 30 that comprises a color vision system according to the invention, based on a dichroic blade 119 and networks 121

and 122 of optical fibers.

  In the case of the separation device 10, the dichroic blade 119 makes it possible to separate the spectral ranges of the field corresponding respectively to the different input zones. Indeed, the light beams pass through the optical system 9, arrive on the dichroic plate 119 which separates them in the upper half of the light beams focusing on the input face 221 of the upper network 121 of optical fibers and in the lower half of the light beams focusing on the input face 222 of the lower network 122 of optical fibers. The upper 121 and lower 122 arrays respectively guide the upper and lower halves of light beams so that these arrive respectively at the upper 21 and lower 22 input areas of the input image surface 20. In the case of the 30 recombination device, the dichroic blade 119 makes it possible to recombine the different images respectively from the different output zones by superimposing them so as to form the image displayed in color which represents the object field. The intensified images of the object field are available respectively on the upper 24 and lower 25 output areas of the output image surface 23. These intensified images are respectively guided by the upper 121 and lower 122 networks so as to arrive respectively at the faces. of upper 221 and lower 222 output from upper 121 and lower 122. networks. The intensified image coming from the upper face 221 is reflected by the mirror 120 before arriving at the level of the dichroic plate 119 while the intensified image coming from the lower face 222 arrives directly at the level of the dichroic plate 119. These intensified images are recombined and filtered by the dichroic plate 119 so as to be superimposed between each other, each intensified image constituting one of the spectral components of the image viewed in color available downstream of the optical system 9: for example, the intensified image coming from e the upper face 221 forms the green spectral component of the image displayed in color while the intensified image coming from the lower face 122

  forms its red spectral component.

  In a variant of the seventh embodiment, the angular deflection of the light in the recombination device is carried out by at least one semi-reflecting plate, a mirror situated upstream from the semi-reflecting plate, and several fiber networks optics which are arranged parallel to each other, which have different lengths, which are located downstream of the output image surface and which are integrated into the intensifier, the semi-reflecting plate, the mirror and the optical fiber networks being arranged so as to add an additional optical channel for binocular vision. The dichroic plate 119 of FIG. 16 is replaced by a separating plate while two filters corresponding for example to the green and red spectral components are added between the exit zones and the separating plate 119. The green filter is for example placed between the face upper 221 and the mirror 120. The red filter is for example placed between the lower face 222 and the separating blade 119. In the direction D shown in FIG. 16, another optical system 9 not shown allows an additional optical channel forming a second color image identical to the first,

  thus allowing binocular vision.

  Another embodiment consists in using diffractive elements in the separation device 10 and / or in the recombination device 30. Each of the seven preferred embodiments described above allowing the production, either of a separation device 10, or of a recombination device, or of both at the same time, is of interest. These embodiments are relative to

  others more or less advantageous, depending on the criteria considered.

  In terms of the total energy collected, the third to seventh embodiments are more advantageous than the first and second embodiments, since the entrance pupil of the vision system in

  color according to the invention is not separated into several pupil portions.

  At the level of a possible switching, described in detail later, between a color vision mode and a monochrome vision mode, this switching is possible for the first, fourth and fifth embodiments, it is however impossible for the third , sixth and seventh embodiments for which all or part of the separation device 10 and / or of the recombination device 30

  is physically integrated into the light intensifier 2.

  In terms of resolution, the first, second, fourth, fifth, sixth and seventh embodiments are more advantageous than the third embodiment which exhibits a loss of a factor r / in one of the dimensions of the image displayed in color because of the orientation of the faces 206 and 207 respectively of the networks 106 and 107 of

optical fiber.

  In terms of the relationship between complexity and cost, the first, third, fifth and seventh embodiments are simpler and

  less expensive than the second, fourth and sixth embodiments.

  In terms of a possible parallax problem when the object field observed is in a region close to the color vision system according to the invention, the third to seventh embodiments are more advantageous than the first and second embodiments; indeed the third to seventh embodiments do not present a parallax problem since the entrance pupil of the color vision system according to the invention is not separated into several pupil portions

  as in the first and second embodiments.

  In using a fiber optic intensifier as a light intensifier 2, the more expensive fiber optic intensifier than a conventional intensifier is required for the third, fifth, sixth and seventh embodiments which are less

  advantageous than the first, second and fourth embodiments.

  In terms of the use of the color vision system according to the invention in applications requiring a bend in the optical architecture of the vision system, the fifth to seventh embodiments are more advantageous than the first to fourth embodiments since the fifth embodiment is already bent and the sixth and seventh embodiments can easily be bent. In terms of the existence of a variant allowing binocular vision for applications requiring it, the sixth and seventh embodiments, having such a variant which are particularly easy to implement, are more advantageous than the first to fifth modes.

of achievement.

  The output image surface 23 of the light intensifier 2 is preferably a screen of white color, that is to say a screen which emits white light or at least light appearing to be white because it is constituted of several spectral components such as red, green and blue, the sum of these components

  spectral giving a light appearing as white light.

  The white light screen is for example a white phosphor screen or

  well for example a liquid crystal viewer.

  A frame materializing the exit zones is preferably arranged downstream of the light intensifier 2. This frame is advantageously arranged at the level of the output image surface 23 of the intensifier 2 and it delimits the contours of the output zones which can for example be two superimposed rectangles as in certain preferential examples described previously. This materialization of the exit zones is advantageous for the comfort of the user because it avoids the risk of the presence of bordering monochrome zones in the image viewed in color observed by the user of the color vision system. In the case of a light intensifier 2 having one or more integrated networks of optical fibers located upstream of the input image surface 20, the presence of the materialization frame upstream of

  The intensifier 2 is easily conceivable.

  The spectral filtering in the separation device 10 is preferably carried out twice, on the one hand at the level of the entrance pupil of the vision system and on the other hand at the level of the image input surface 20 of the intensifier 2. Similarly, the spectral filtering in the recombination device is preferably carried out twice, on the one hand at the level of the exit pupil of the vision system and on the other hand at the level of the image surface of output 23 of the intensifier 2. This duplication of the spectral filtering, both upstream and downstream of the intensifier 2, makes it possible to solve possible problems such as

  stray images and off-screen light beams.

  The color vision system according to the invention preferably comprises switching means making it possible to retract the separation and recombination devices 10 so that the color vision system switches to monochrome vision mode. In this advantageous option, the vision system has a separation device 10 and a recombination device 30 making it possible to obtain an image displayed in color. In the separation and recombination devices 10, a certain part of the light energy is lost, in particular at the level of the filtering function. This loss of energy is not a problem as soon as the light energy at the level of the object field is not too low. The color vision system then operates in color mode, that is to say in the previously described mode in which the separation and recombination devices 10 are functional. In the case where the light energy at the level of the object field is very low, it is advantageous to be able to operate in monochrome mode as in conventional monochrome vision systems. For this, there is a monochrome mode in the color vision system according to the invention. Switching to monochrome mode from color mode is preferably carried out on the initiative of the user, by retracting the separation and recombination devices 10. Conversely, the transition from monochrome to color mode is achieved by replacing the separation and recombination devices 10. While allowing color vision in most cases, this option allows you to fall back on classic monochrome vision in case of very

  low light, for better user comfort in all cases.

  A preferred field of application of a color vision system according to the invention is the military and paramilitary field in which night vision is of great importance. In observation, such a color vision system is especially interesting for detection, but also for recognition. When driving a vehicle, such a color vision system can allow faster identification of

  the environment in which the vehicle is traveling.

  A first preferred application of a color vision system according to the invention relates to a night vision binocular. The sixth and seventh embodiments are particularly advantageous in the case of a pair of binoculars because they have a variant which easily allows binocular vision. The pair of binoculars is mainly used for observation, it typically weighs a few hundred grams, for example. A second preferred application of a color vision system according to the invention relates to a helmet. The helmet is mainly used for driving a vehicle on the move, it weighs for example

typically one kilogram.

  A third preferred application of a color vision system according to the invention relates to an episcope. The fifth to seventh embodiments are particularly advantageous in the case of an episcope because, either they are already bent, or they can easily be bent. The episcope is mainly used for driving a tank type vehicle, it is generally integrated and typically weighs around fifteen kilograms, for example. A fourth preferred application of a color vision system according to the invention relates to a telescopic sight. The glasses

  sight is for example mounted on a rifle.

Claims (37)

  1. A color vision system comprising, a light intensifier (2) comprising an input image surface (20) and an output image surface (23), a lens (1) being located upstream of the intensifier ( 2) and imaging an object field at the level of the input image surface (20) of the intensifier (2), a display device (3) being located downstream of the intensifier (2) and imaging the image surface output (23) of the intensifier (2), characterized in that the input image surface (20) of the intensifier (2) has several spatially distinct input zones (21, 22) and the image surface exit (23) of the intensifier (2) comprises several spatially distinct exit zones (24, 25) corresponding respectively to the entry zones (21, 22), in that the objective (1) comprises a device ( 10) of separation spectrally filtering and angularly deflecting the light so that the objective (1) image respectively at level of the different input zones (21, 22) different spectral ranges of the same object field, and in that the display device (3) comprises a recombination device (30) spectrally filtering and angularly deflecting the light so that that the display device (3) images all the output zones (24, 25) by superimposing them so as to form an image displayed in object field color.   2. Color vision system according to claim 1, characterized in that the input image surface (20) of the intensifier (2)   consists of two to four entry areas (21, 22).   3. Color vision system according to claim 2, characterized in that the input image surface (20) of the intensifier (2)   consists of two entry areas (21, 22).   4. Color vision system according to any one of   previous claims, characterized in that all entry areas (21, 22) are identical.   5. Color vision system according to claims 3 and 4,   characterized in that the input image surface (20) of the intensifier (2) is circular, in that each input zone (21, 22) comprises a rectangle (rs, ri) inscribed in the set constituted on the one hand by a semicircle (cs, ci) of the input image surface (20) and on the other hand by the diameter (d) which underlies said semicircle (cs, ci), both rectangles (rs, ri) having a large common side, in that on the side of each of the short sides (pc) of each rectangle (rs, ri) the entry area (21, 22) corresponding to the rectangle (rs, ri ) is extended by an additional surface (sad) delimited by two arcs of a circle (acl, ac2) one of which (acl) follows the contour of the input image surface (20), the tracing of the arcs of a circle (acl , ac2) being arranged so that one of the entry zones (21, 22) is the transformed of the other by a translation of direction perpendicular to that of the large common side and of length   equal to that of a small side (pc) of rectangle (rs, ri).   6. Color vision system according to any one of   claims 1 to 4, characterized in that the entry areas (21, 22) are,   either all 16/9 rectangles, or all rectangles of 4/3 format.   7. Color vision system according to any one of   claims 3 to 6, characterized in that the spectral ranges of the two   entry zones (21, 22) are the near infrared and the visible.   8. Color vision system according to claim 7, characterized in that the exit zone (25) corresponding to the visible spectral range is restored by the display device (3) in red color and in that the exit zone (24) corresponding to the near infrared spectral range is restored by the display device (3) in green color. 9. Color vision system according to any one of   previous claims, characterized in that the device (3) for   display includes an eyepiece (8) located downstream of all the others optical elements of the system.   10. Color vision system according to claim 9, characterized in that the display device (3) comprises a transport   image (5) located between the intensifier (2) and the eyepiece (8).   11. Color vision system according to claim 10, characterized in that the display device (3) comprises at least one device (6) with charge coupling and a screen (7), successively located   between the image transport (5) and the eyepiece (8).   12. Color vision system according to claim 11, characterized in that the device (6) with charge coupling on the one hand has a sensitive surface (60) which comprises several useful zones corresponding respectively to the exit zones (24, 25) and on the other hand is oriented so that the height of the object field is imaged on the large   dimension of the sensitive surface (60) of the charge coupled device (6).   13. Color vision system according to any one of   Claims 11 to 12, characterized in that the coupling device (6)   charge is a device (6) with color charge coupling and in that the recombination device (30) is entirely optical and located upstream   of the charge coupled device (6).   14. Color vision system according to claim 11, characterized in that the display device (3) comprises several charge coupling devices (6) all located upstream of the recombination device (30), the sensitive surfaces (60 ) coupled devices (6)   load corresponding respectively to the exit zones (24, 25).   15. Color vision system according to any one of   Claims 1 to 9, characterized in that the display device (3)   comprises a device (6) with charge coupling integrated into the intensifier (2) and located downstream of the output image surface (23), and a screen (7) located in downstream of the intensifier (2).   16. Color vision system according to one of claims   11 to 13 or 15, characterized in that an anamorphosis is introduced into the objective (1) and / or into the image transport (5) so as to adapt the format of the output image surface (23) of the intensifier (2) in the format of   the sensitive surface (60) of the charge coupled device (6).   17. Color vision system according to one of claims   11 to 12 or 14 to 16, characterized in that the recombination device (30)   is made up of entirely electronic processing means.   18. Color vision system according to any one of   previous claims, characterized in that the entrance pupil of   the objective (1) is formed of several pupil portions, the portions of   pupil corresponding respectively to the entry zones (21, 22).   19. A color vision system according to claim 18, characterized in that the angular deflection of the light in the device (10) for separation is produced by several prisms (101, 102) placed side by side, the   prisms (101, 102) corresponding respectively to the pupil portions.   20. A color vision system according to claim 18, characterized in that the angular deflection of the light in the separation device (10) is produced by several truncated lenses (103, 104) placed side by side situated in the same plane and linked between them by their truncated part. 21. A color vision system according to claim 20, characterized in that the offset (d), in a plane orthogonal to the direction of propagation of light, existing between the centers (Is, li) of the truncated lenses (103, 104) is equal to the offset (d) existing between the centers (zs,   zi) corresponding entry zones (203, 204).   22. Color vision system according to any one of   Claims 3 to 17, characterized in that the spectral filtering and the   angular deflection of the light in the separation device (10) and / or in the recombination device (30) are produced by a dichroic plate (105) and by two networks (106, 107) of optical fibers which are located upstream of the input image surface (20) and / or downstream of the output image surface (23), which are integrated into the intensifier (2), and whose faces   inlet (206, 207) are arranged orthogonally to each other.   23. Color vision system according to any one of   claims 3 to 17, characterized in that the spectral filtering and the   angular deflection of the light in the separation device (10) and / or in the recombination device (30) are produced by two prisms (108, 109) which are arranged head to tail and whose spectral transmission at least   minus certain faces (111,112) depends on the incidence of light.   24. Color vision system according to any one of   claims 3 to 17, characterized in that the spectral filtering and the   angular deflection of the light in the separation device (10) and / or in the recombination device (30) are produced by a blade with non-parallel faces (113, 114) whose upstream face (114) is a spectral filter while that the downstream face (113) is a mirror whose reflecting side is arranged inward of the blade.   25. Color vision system according to any one of   Claims 1 to 17, characterized in that the spectral filtering and the   angular deflection of the light in the separation device (10) and / or in the recombination device (30) are produced by at least one   dichroic blade (115) and several mirrors (116, 117, 118).   26. Color vision system according to any one of   Claims 1 to 17, characterized in that the angular deviation of the   light in the recombination device (30) is produced by at least one semi-reflecting plate (115) and several mirrors (116, 117, 118), the semi-reflecting plate (115) and the mirrors (116, 117, 118) being arranged to add an additional optical path for binocular vision. 27. Color vision system according to any one of the   Claims 1 to 17, characterized in that the spectral filtering and the   angular deflection of the light in the separation device (10) and / or in the recombination device (30) are produced by at least one dichroic plate (119), several networks (121, 122) of optical fibers which are arranged in parallel between them, which have different lengths, which are located upstream of the input image surface (20) and / or downstream of the output image surface (23), which are integrated into the intensifier (2), and at least one mirror (120), each mirror (120) being located between the dichroic blade (119) and   one of the networks (121,122) of optical fibers.   28. Color vision system according to any one of   Claims 1 to 17, characterized in that the angular deviation of the   light in the recombination device (30) is produced by at least one semi-reflecting plate (119), a mirror (120) situated upstream from the semi-reflecting plate (119), and several networks (121, 122) optical fibers which are arranged parallel to each other, which have different lengths, which are located downstream of the output image surface (23) and which are integrated into the intensifier (2), the semi-reflective strip (119), the mirror (120) and the optical fiber networks (121, 122) being arranged so as to add an additional optical channel for vision binocular.   29. Color vision system according to any one of   Claims 1 to 17, characterized in that the spectral filtering and the   angular deflection of the light in the separation device (10) and / or in the recombination device (30) are produced by one or more diffractive elements.   30. Color vision system according to the claims   previous, characterized in that the output image surface (23) of   The intensifier (2) is a white screen.   31. Color vision system according to the claims   previous, characterized in that a frame materializing the exit zones   (24, 25) is arranged downstream of the intensifier (2).   32. Color vision system according to the claims   above, characterized in that the spectral filtering in the separation device (10) is carried out twice, on the one hand at the level of the entrance pupil of the vision system and on the other hand at the level of the image surface d entry (20) of the intensifier (2) and in that the spectral filtering in the recombination device (30) is carried out twice, on the one hand at the exit pupil of the vision system and on the other hand at the level of the   output image surface (23) of the intensifier (2).   33. Color vision system according to the claims   previous, characterized in that the system includes switching means making it possible to retract the separation and recombination devices (10) so that the color vision system switches to monochrome vision mode.   34. Night vision binoculars characterized in that it comprises a color vision system according to any one of claims 1 to 33.   35. Helmet characterized in that it includes a vision system   in color according to any one of claims 1 to 33.   36. Episcope characterized in that it comprises a system of   color vision according to any one of claims 1 to 33.   37. Riflescope characterized in that it comprises a   color vision system according to any one of claims 1 to 33.