FR2780517A1 - Stereoscopic laser visualization apparatus for video signal images - Google Patents

Abstract

The device for stereoscopic laser visualization in transmission of video signals comprises two laser systems containing primary optical sources, left and right (IG,ID), which are coupled with two collimation systems (2G,2D) for visual display. The laser systems produce three monochromatic beams, blue, green and red (5b,5v,5r), which are modulated by the image monitors (8G,8D), which have the role of secondary optical sources.- DETAILED DESCRIPTION - The device includes primary laser sources which are for example light emitting diodes (LEDs), and the pixel image monitors are of the liquid crystal display (LCD) type. The collimation system is convex or biconvex, with a diameter equal to the diagonal of image monitors. At the first stage, the beams from the primary laser sources form a large angle (alpha) beam. The blue and green laser sources are with concave optical components, and the red beam is reflected from a convex mirror. The beams from secondary sources are reflected from plane or parabolic mirrors, centered on the optical axis of observer's eye. In the second embodiment of the invention, the image monitors contain matrices of pixels and semiconductor laser diodes. In the third embodiment, the monitors are of a form with a parabolic curvature

Description

The present invention relates to a display device for

  stereograms, from a transmission of video signals reproduced in the form of images in relief by

two laser broadcasters.

  The reconstruction of the relief from flat images can be carried out using the anaglyph technique or stereophotography known since the beginning of the century. The relief vision is based on the so-called stereoscopic or three-dimensional binocular vision. The stereoscopic depth10 is given by the difference in ocular perspective or by the neural calculation of the slight differences in position of the points which correspond on the retina. These differences are due to the distance between the two eyes, whose points of view thus differ slightly (phenomenon of 15 parallax). Binocular convergence is regulated by the positioning of the directed eye as a function of the directing eye, by superimposing the image of its fovea on that of the other eye. To this end, the duplication of the image disappears precisely on the fovea of each eye, which coordinates together on the same object point. The doubling of the object points becomes more significant as we move away from the center of the fovea. Under normal conditions, stereoscopic vision plays an important role in the perception of random shapes or objects such as the leaves of a tree. Likewise, the presence of linear objects or elements is not essential to the phenomenon of stereoscopic fusion and depth. Using stereoscopic images made up of randomly arranged dots, inside a stereogram, the dots of a region of the image which are laterally shifted appear in that region, in front or behind of the rest of the image. picture. however, even if binocular convergence is fairly easily established by superimposing images, it is important to note35 the induction of certain paradoxes of perception of an image in relief, when it comes from a stereogram. For example, it is interesting to note that certain perceptions of monocular depth, through the accommodation of the lens, can erase the stereoscopic depth when it is opposed to them. When a perspective scene is observed through a stereoscopic system in which the images are inverted before the eyes, the depth remains perceived normally, the illusion of perspective being stronger than stereoscopic vision. Stereoscopic vision being a reality of binocular vision, associated with the accommodation of the lens of each eyepiece, the visualization of a stereogram, does not always provide us with the adaptation of our entire vision system. This is due to the observation that a stereogram does not take into account all the laws of geometric optics, at the

  how our vision system apprehends and articulates them to create a raised image.

  Certain devices that have become conventional for viewing a fixed or animated stereogram, in connection with the invention, retransmit the images of a scene on two small viewing screens2), also arbitrarily called monitors, by means of one or two cameras ( s), whose framing is respective from two different points of view. The visualization is carried out by bringing each miniature monitor closer to each eyepiece and respectively from the point of view relating thereto. The monitors being too close to the eyes to clearly perceive the images, a lenticular optical system of global collimation, makes it possible to strongly correct the accommodation of the lens of each eyepiece, which forms for the monocular depth a final image3) at infinity. By global collimation is meant the focusing of all of the light beams or rays coming from the pixel points of the passing image, for example through a convex diopter. The configuration of a stereogram, on both

  monitors, related to these conventional devices is defined by the two-dimensional image of each small screen.

  From the point of view of binocular vision, it is only the two-dimensional coordinates of the same object point, different on the abscissa for each monitor, which define binocular convergence. 5 The projection of a two-dimensional image of a monitor is resolved by a mosaic of electroluminescent pixels covering its surface. Each pixel diffuses incoherent light in all directions, identical to a point light source coming from a point10 object of three-dimensional spatial coordinates. From the point of view of monocular vision, it is only the degree of divergence of the light beam, connecting the object point to the incident point of the eyepiece (the cornea), which defines the curvature of the lens. In popularizing the idea, we will say15 that if the two-dimensional image projected into the brain can give us the illusion of relief thanks to perspective, the relative size of objects and others, the accommodation of the lens, on the other hand, responds depending on the optical reality of the divergence of the light beam without worrying about whether it is an image point or an object point. For the accommodation of the lens, all the light scattering points are object points. Within the framework of such a stereoscopic visualization, we will note here that all the pixel points or image points of a monitor, 25 representative in real space of object points, are distributed substantially at the same distance from the eyepiece, therefore at the same distance from the lens. In the context of stereoscopic vision, this two-dimensional distribution at equal distance between the pixel points and 3 () the eyepiece results in an unusual effort to accommodate the lens of each eyepiece. The accommodation of the lens of each eyepiece is no longer correlated with binocular vision responding normally by an interrelation to the same commands of the central nervous system35. Indeed, this interrelation between the accommodation of the lens of each eyepiece and the convergence

  binocular can be translated by an evolution curve.

  According to the coordinates where the accommodation of the lens on the abscissa (expressed in diopters) is a function of binocular convergence on the ordinate (expressed in metric angle5), for an increasing distance on the median optical axis, The curve obtained corresponds to the bisector the angle of the coordinate axes. However around this position of equilibrium, a certain flexibility of evolution is allowed because of the relative amplitude of the two variables, one with respect to the other, to ensure the maintenance of a stereoscopic fusion. Experiments carried out in the context of research in visual perception in 1966 by Bela Julesz director of research in visual perception of the T. Bell laboratories and associate professor of the California Institute of Technology in the United States, confirms that after the decoupling of these two factors, changes in ocular accommodation seem to act only through their strong correlation to the state of binocular convergence. To return to this linear variation of the accommodation of the lens as a function of binocular convergence, it can be understood by taking into account the median optical axis, representative of a light beam of diverging rays of an angle of degree a as having a direct relationship with vision. In the context of the raised mink, we can consider three logico-mathematical relationships between three action factors which are; 1): the laws of the rectilinear propagation of light (in incoherent light) of a light beam coming from an object point, which at the incident point of the eyepiece (the cornea) and of the inter ocular front (distance between the two eyepieces), is characterized for each by a divergence of an angle ad; 2): binocular convergence, of a metric angle ac on the observation of the object point; 3): the curvature of the lens of dioptric power D for its accommodation35 at the object point. The logical-mathematical relationships are as follows; 1): the binocular convergence of metric angle ac varies in the same proportions as the degree ad of the angle of divergence of the light beam at the point of incidence of the inter ocular front, according to the distance D 'from an object point; 2): the curvature of the lens of optical power D varies in the same proportions as the degree ad of the angle of divergence of the light beam at the point of ocular incidence, according to the distance D 'from an object point; 3): the curvature of the lens of optical power D varies in the same proportions as the binocular convergence of metric angle ac, according to the distance D ', of a

point object.

  To this end, we can deduce that for each object point located at a distance D 'in real space in three dimensions and source of an incoherent light scattering, 15 are associated with it simultaneously in the context of observation by vision. stereoscopic, a degree ad of the angle of divergence for the light beam incident at the eyepiece and that incident at the inter ocular front, a degree ac of metric angle for the binocular convergence and an optical power D for the curvature of the lens. In other words, the set of these interactive factors, developed explicitly, represents the basic postulate demonstrative, of a nature to understand and correct the paradox of stereoscopic visualization.25 To follow our development, with each new binocular convergence oriented on an object point, following a change of gaze, via the directing eye by reflex or consciously, the lens of each eyepiece, adapts in less than 500 thousandths of a second in automatic response30 of its ciliary muscles. The pair of binocular convergence and monocular accommodation of strong correlation depend on the central nervous system. In the classic cases of viewing stereograms, the central nervous system often very well accommodates the curvature of the lens by the unusual effort of seeking the highest frequency of retinal stimuli. This effort can be interpreted as the compensation for a return to equilibrium of the third logico-mathematical relation with respect to

  the gap appeared from the second logical-mathematical relationship.

  In the context of viewing a stereogram, whatever the coordinates of the pixel points distributed on the two-dimensional display screen, the degree ad of the angle of divergence of the light beam at the incident point of the eyepiece from a any pixel point is identical to all the others and this whatever the binocular convergence it is likely to cause. this configuration does not take into account the second logico-mathematical relation which stipulates that each object point represented at a different distance D 'in comparison with other object points, must relate to a degree ad of the angle of divergence of the beam different light at the incident point of the eyepiece. The first logical-mathematical relationship likewise undergoing a paradox, binocular convergence is not affected by its deviation because it always confuses20 the line of gaze along the optical axis of each eyepiece, whatever the degree of divergence of the incident beam at the eyepiece (the cornea). For binocular convergence, the eyepieces only take into account the marginal rays of the light beam from an object point. It follows therefore, that for stereoscopic vision, only the superposition of two object points, following shape lines, is taken into account by the neuronal calculation of the nervous system. It is for this essential reason that the stereograms are observable. The curvature of the lens which30) logically follows this binocular convergence should focus the light beam of degree of angle cD of identical divergence, of each pixel point, in front of or

  behind the ocular retina according to the relational gap thus obtained. But the accommodation of the lens35 having a flexibility of evolution of relative amplitude, this-

  this constantly corrects the deviation thus imposed via the central nervous system. To summarize all this development, the curvature of the lens of unconscious reaction is the programmed response of the nervous system as a function of binocular convergence. A very simple experiment can perfectly demonstrate that it is practically impossible to make the lens work consciously without the support of binocular convergence. Wanting to accommodate the lens of an eyepiece amounts to fixing an object point by the1 (superimposition of the stereoscopic couple of the fovea of each eyepiece. However, the central nervous system can recalculate the focusing of the lens by an unusual effort if a gap is obtained by the search for the highest frequency of retinal stimuli. Binocular convergence15 is an inextricable consequence of the orientation of the gaze, along an optical axis in a conventional field of vision. Even a closed eye, binocular convergence takes place perfectly in concert with the eyes, with the only difference of obtaining a plane image. The constitutive nature20 of our vision system responding to the laws of optics, has inherently and mechanically rendered the application of

  such visual functions. Unusual prolonged effort to accommodate the lens can seriously impair the appreciation of vision by creating disorders that can range from difficulty with alertness, to headaches or eye pain.

  The wealth of information contained in stereoscopic vision has always pushed imagery to use stereograms. With the development of computer science, 30 as far as the power of computers is concerned, synthetic imaging has found notable reinforcement with the use of stereoscopic vision. The perception of the relief constitutes a primordial aid for spatio-temporal location by an instantaneous appreciation, but the prolonged and repetitive use of 35 conventional stereoscopic devices by different professionals, such as surgeons, aircraft pilots, scientists or quite simply, by users of video game simulators or spectators of video sequences, is often poorly appreciated, because of the physiological disorders caused. It is good to mention that a significant percentage of the population is unable to observe a stereogram because of these optical paradoxes. The object of the invention is the production of a stereoscopic display system making it possible to remedy these) drawbacks. It is made up, in fact, of a device capable of correcting the gap with consistency, of one of the three logical-mathematical relationships of relief vision. The logico-mathematical relation which is to be corrected, concerns in its content, the degree of the angle of divergence of the light beam at the incident point of the eyepiece (the cornea) acting on the curvature of the lens, ie the second relation. The first relationship containing the essential basis of the reproduction of stereoscopic vision, it is not affected even if it undergoes a deviation. The third relation20 which is strictly dependent on the nervous system is the one which must remain the most stable. The idea therefore consists in reducing in the second relation, and until nothing, the degree of the angle of divergence of the light beam at the incident point of the eyepiece, of each pixel point resulting from a stereogram, for this fact only preserves the marginal rays strictly parallel to the incident points of the cones of the retina of each eyepiece. It should be noted that in this case and for what follows, a marginal ray is not necessarily linked to the optical axis, but rather to a visual axis. The following effect of this light arrangement is the maximum reduction, of the correction work that the lens performs to accommodate when viewing a stereogram. One can perfectly imagine that the diameter of the beam (of marginal rays) of a practically zero degree of divergence35, coming from a very small pixel point relates directly to the surface of a very reduced number of cones of the retina, without need to correct the focus beforehand when accommodating the lens. Following the necessary criteria relating to the light intensity, the parallelism of the light rays and 5 the beam diameter of the marginal rays, only one

  laser light beam can be used for this purpose.

  The stereoscopic viewing device, according to the invention comprises, two laser broadcasters, each of them respective to an eyepiece, two overall collimation dioptres 10 each of them respective to an eyepiece and a supporting frame. Each of the laser television broadcasters comprises, in its rear part, a set of several sources of primary blue, green or red monochrome light production, originating from semiconductor laser diodes or any other laser sources. In order to constitute an image from a laser broadcaster, we can consider several conditions and stages of the light pathways during their optical processing, from their primary production source to their ocular collimation. A distinction is made between the primary source and the secondary source in that the second comes from a pixel point and the first comes from a source of laser light production, such as a laser diode. It should be noted that a primary source can also be secondary. A distinction is made between six non-restrictive steps, distinct and characteristic of the invention. In a first step, the laser beams of primary source, from their source, must be arranged according to a divergence angle of degree a calculated beforehand, in order to be able to couple the laser beams of primary source of equal diameter on the diagonal of a monitor that they will cross further, with an optical straightening diopter. To obtain this result, each of the primary source laser light beams can be diffracted by a convex mirror or a concave diopter from its source. In a second step, the primary source laser light beams, of an orientation oriented at the base in the laser broadcaster, must be combined together according to their path, so that the marginal radius of each of the primary source laser light beams travels in a direction perpendicular to the spherical plane of an optical rectifier diopter. To obtain this result, each of the primary source laser light beams can be reflected or refracted by one or more mirror (s) with unidirectional reflection of flat or concave shape which can be associated with a prism and each of them being respective. to one or more laser light beam (s) from primary source. By unidirectional reflection is meant the possibility that mirrors with unidirectional reflection have the possibility of passing the laser light beams of primary source in one direction only, which makes it possible to arrange them through the path of a light beam not concerned, without reflect it. In a third step, the primary source laser beams must travel in a parallel arrangement of their rays so that each of the primary source laser beams can cross the screen of a monitor in a direction perpendicular to their rays. . To obtain this result, each of the primary source laser light beams is coupled with a convex or bi-convex diopter of diameter 25 equal to the diagonal of the monitor and each of them respective to the coupling of one to several light beams

  primary source lasers of the same diameter at incident points on its surface. In the case of the second step, if the mirror (s) with unidirectional reflection are of concave shape and if the laser beams of primary source are quite divergent before reflecting on them

  Ci, it is not useful to couple the primary laser light beams with a biconvex diopter. In a fourth step, each of the laser beams of the respective primary source at a chrominance must be modulated in its light intensity from each of its points II located on its directional plane in order to constitute pixels. To obtain this result, the set of laser beams of the respective primary source with three chrominances is coupled with a monitor with 5 liquid crystal LCD cells with active matrix by substituting the laser beams of primary source for the set of LED diodes. luminescent. Each of the primary source laser light beams being respective to a chrominance, each pixel of the monitor consisting of one to several 10 liquid crystal cells, each of which is associated with a respective chromatic filter to the chrominance of a laser light beam of primary source passing through it. To this end, each of the liquid crystal LCD cells modulates the intensity of a portion of the laser light beam from the primary monochromatic blue, green or red source depending on the video signal via the switching of a semiconductor transistor. Each pixel point in the directional plane of a primary source laser light beam representing the dimensions of a liquid crystal cell, the diameter of the directional plane of the primary source laser light beam must be equal to the diagonal of the screen. monitor display. The modulation of the light intensity proper to each of the pixel points of the directional plane of the primary source laser light beam, is carried out through each liquid crystal cell respectively with its blue, green or red colored filter. In a fifth step, When the laser beams of primary source pass through the liquid crystal cells LCD, these undergoing diffraction, the laser beams of secondary source thus produced, must be made parallel again. To obtain this result, each of the secondary source laser light beams is coupled with a biconvex diopter designed to the size of the secondary light source laser beam. In a sixth step, if the path of the laser beams of secondary source is not parallel to the optical axis of the eyepiece of the observer, after the fifth step, each of the laser beams of secondary source must be reoriented for eye collimation of the observer. To obtain this result, each of the secondary source laser light beams is reflected by a set of prisms or mirrors of planar or concave shape so that the laser beam beam of central secondary source is coincident with the optical axis of the eye of the observer. At the output10 of the laser broadcaster, the laser beams of parallel rays with regard to the final path

  should be collimated to the observer's eyepiece, so that the focus is around the center of the eye lens. In this case, the laser broadcaster 15 is supplemented by a convex or biconvex overall collimating diopter, of dioptric power calculated beforehand.

  However, a parabolic mirror as mentioned in the sixth step, can replace a global collimation diopter, if this is close enough20 to the eyepiece, For the following logical effect, an associated global collimation lens respectively to one of the laser broadcasters, each of them respective to each eyepiece of the observer, refracts each of the laser beams of secondary source towards the cells of the retina of the observer. This optical refraction of a different angle ax for each laser light beam and symmetrical from one eyepiece to the other, is representative in the visual field of an observer, of an optical direction line 30 of an object point or d '' a possible visual axis of an object point, provided that the image is placed respectively in its eyepiece. A single laser light beam for each eyepiece can be representative of an optical axis. According to another embodiment respectively at

  a laser broadcaster, this uses a monitor made up of a mosaic of pixels with semi-laser diodes

  conductors, which will mean what it involves by achieving a flat shaping of the laser broadcaster. Each semiconductor laser diode, so to speak, is a spatial replacement for a liquid crystal cell. Therefore, three functions can be generated within them; the production of a laser light beam, the modulation of its intensity and the definition of its chrominance. The modulation of the light intensity replaces the liquid crystal cells, the defined chrominance of each semiconductor laser diode replaces the filter associated with each liquid crystal cell and the primary light source of all the laser diodes is substitute for the primary source of all the laser light beams. Under these conditions, it can be considered that the first four steps can be canceled by replacing all of the semiconductor laser diodes with all of the liquid crystal cells representing each other, the pixel mosaic. In summary, in the second embodiment, the laser broadcaster does not include a concave diopter or convex mirrors, nor mirrors with unidirectional reflection, nor a bi-convex optical rectifier diopter, nor a crystal cell screen monitor. LCD liquid. In this variant embodiment and up to the fourth step 25 included, the laser broadcaster comprises a monitor whose pixels consist of three laser diodes also called semiconductor lasers or heterojunction laser diodes and diffusing for each of them from from their emitting area a light beam of parallel rays of respective chromatic source in a blue, green or red color. The quality of the material chosen in the constitution of

  semiconductors is respective of the desired color. By way of example, the laser diodes with red chromatic emission can be made up, from GaAsP compound or35 from said quaternary compound InGaAlP distributed in several successive layers, relative to the p- junctions.

  not. To produce the wavelengths of visible red around 650 nm, the mixing ratios determine the exact wavelength. The laser diodes of each pixel are connected by each of their p-n 5 junctions to the terminals of an electrical voltage + and -. Each laser diode emits light in proportion to the intensity of the electric current passing between the two p-n junctions originating from the switched matrix video signal and amplified by a semiconductor transistor. The advantage of a 10 semiconductor laser diode lies in the possibility of instantaneously modulating the light intensity scattered from its emitting area as a function of the intensity of a current passing through the terminals of the pn junctions. . The function of emitting a light intensity in pulsed mode gives it 15 good walking conditions while respecting the observer's retinal ocular remanence. In addition, the function of modulating this light intensity in an instantaneous manner, supersedes it to the function of liquid crystal cells, commonly used for screens20) flat LCDs with active matrices. The dimension of a laser diode in the plane of its emitting area must have a surface of the order of ten thousandths of a square millimeter, this in order to constitute relatively small pixels for a correct resolution of the image of a monitor. about 2.5 cm diagonal. The precision of the parallelism of the rays of the laser light beams of secondary source must relate to an angle a of the laser light beam much less than a thousandth of a degree. According to a technique for producing the pixel mosaic of a monitor, the laser diodes are designed so that their different superimposed layers which constitute the p-n junctions, are parallel to the plane of the screen of each monitor. The light source of each laser diode not being perpendicular to the plane of its respective monitor but parallel, the laser light beams of secondary source must be redirected by 90 degrees. In this case, each of the secondary source laser light beams is reflected at 90 degrees by a respective flat or concave mirror.

  this one or more laser light beam (s).

  However, if this kind of embodiment is necessary for semiconductor laser diodes of conventional manufacture, the current technique proposes laser diodes whose emitting area is perpendicular to the superimposed layers of the p-n junctions. Since they can be manufactured in large numbers on the same wafer of superimposed layer of semiconductor, the idea of constituting a laser diode monitor directly on a wafer is not excluded. To return to the continuation, the passage of the laser beams of primary source, at the exit of the emitting area of the semiconductor laser diodes being characterized by a light diffraction, the fifth stage is maintained, in that the laser beams of secondary source thus produced, must be made parallel again. To obtain this result, each of the secondary source laser light beams is coupled with a convex bi-2 () diopter designed to the size of the secondary source laser light beam. Regarding the sixth step, if the

  path of the secondary source laser light beams is not parallel to the optical axis of the observer's eyepiece, after the fifth step, each of the secondary source laser light beams must be redirected towards an ocular collimation of the observer.

  To obtain this result, each of the secondary laser light beams is reflected by a set of prisms or mirrors of planar or concave shape so that the marginal radius of each of the secondary laser light beams travels in a direction parallel to the axis

  optics of the observer's eyepiece. As in the previous mode, a parabolic mirror as mentioned in the sixth step, can replace a diopter of global collimation, if this is sufficiently close to the eyepiece.

  According to a variant of this embodiment, a flat laser broadcaster includes a

  parabolic form whose interest is to substitute its curvature for the overall collimation diopter normally5 associated with the laser broadcaster, provided that it is flat and sufficiently close to the eyepiece.

  Two particular embodiments of a stereoscopic viewing system as well as a variant of

  embodiment of one of these modes will appear in the description which follows, given by way of nonlimiting example

  using the appended figures which represent: FIG. 1, a drawing of a sectional view of a first embodiment of a stereoscopic display device, in accordance with the present invention. FIG. 2, a drawing of a sectional view of a second embodiment of a stereoscopic display device according to the present invention and associated with the example from a stereoscopic point of view. Fig. 3, a drawing of a sectional view of a variant of the

  second embodiment of a stereoscopic display device according to the present invention.

  With regard to each of the elements of the stereoscopic viewing system respectively on each of the sides and for better clarity, each of the numbered elements may be associated with a G for the left side and a D for the right side. As for each of the numbers to which they will be referred, for all the descriptive development which will follow, each color will be represented by the letter "b" for blue, by the letter "v" for green30 and by the letter "r" for red. Also, a set of identical elements will be represented by the letter "x" when it will not be useful to specify a precision concerning one of them. According to FIG. 1, The display system is

  consisting of two laser broadcaster (1G) and (1D) of elongated shape and two collimating dioptres. (2G) and (2D).

  The supporting frame in this case is merged with the profile of each of the laser broadcasters (1G) and (ID) according to an ergonomics of modeling of their external walls, for a helmet carrying the entire stereoscopic display system. The two laser broadcasters (1G) and (lD) constitute by their outer walls the branches (19G) and (19D), each of them resting on one side of the observer's head. Each of the laser broadcasters (1G) and (1D) is joined with the other in the middle of the observer's interocular forehead to become a support leg (21). In addition to the function of acting as a headset, the laser broadcasters (1G) and (lD) also fully represent two production, tracking and optical processing enclosures. Each of the laser broadcasters (1G) 15 and (1D) comprises in its rear part, a set of three laser diodes (4b), (4v) and (4r) with semiconductor of primary light production source monochrome blue, green, or red . As regards what will follow each of the two laser broadcasters (1G) and (lD) in the first step, the laser light beams (3b), (3v) and (3r) of primary source are diffracted according to a larger angle a by coupling the laser light beams (3b) and (3v) of primary source on two concave diopters (11b) and (11v) and by reflecting the laser light beam (3r) of primary source with a convex mirror (10r) . According to the second step, the laser light beams (3v) and (3r) from primary source are reflected off at an angle adapted by two mirrors with unidirectional reflection (12v) and (12r) of planar shape and themselves crossed by the laser light beam. (3b) being disposed thereof perpendicular to the righting diopter (13). According to the third step, in order to obtain a parallelism of their rays, and in order to make each of these rays cross perpendicular to the monitors (8G) and (8D), each of the 35 laser light beams (3b), (3v) and (3r) of primary source is coupled with a bi-convex diopter (13) of diameter equal to the diagonal of a monitor and of itself corresponding to the coupling of the three laser light beams (3b), (3v) and (3r ) from primary source. The diffractions caused by the convex mirror (0lr) and by the concave diopters (11b) and (11v), must be calculated respectively for each of the laser light beams (3b), (3v) and (3r) of primary source in order to obtain for each of them at the incident points of the biconvex diopter (13) a diameter D 'to their perpendicular directional plane, of a length equal to the diagonal of the monitor screen (8). According to the fourth step, each of the laser light beams (3b), (3v) and (3r) of respective primary source with a chrominance, is modulated by its light intensity from each of the points of its perpendicular directional plane, knowing that the dimension and the coordinates of one of these points represent that of a liquid crystal cell. To do this, each of the laser light beams (3b), (3v) and (3r) of respective primary source to a chrominance is coupled with a20) monitor (8) with liquid crystal cells LCD with active matrix by substituting the light beams. lasers (3b), (3v) and (3r) from primary source to all of the LED luminescent diodes. The monitor (8) is of a conventional constitution. Each of the pixels (7.x) consists of three25 liquid crystal cells each associated with a blue, green or red filter. For clarity regarding the example of a binocular vision which will be associated with FIG. 2, the pixel mosaic (7.x) is represented by a line of only 9 pixels per monitor, numbered (7G.1) (7G.2) (7G.3) (7G.4) (7G.5) ( 7G.6) (7G.7) (7G.8) (7G.9) for the monitor (8G) and (7D.1) (7D.2) (7D.3) (7D.4) (7D.5 ) (7D.6) (7D.7) (7D.8) (7D.9) for the monitor (8D). Each of the cells is switched to a transistor which manages the modulation of the light intensity as a function of the video signal, during the passage through the color filter of the respective primary source laser light beam to the color of the filter. As a result, three laser light beams, blue, green and red, of primary source and rays strictly parallel, have been substituted for all of the LED luminescent diodes which traditionally constitute the active matrix LCD liquid crystal screen. According to a fifth step, the LCD liquid crystal cells being able to cause diffraction during the passage of the laser light beams (3b), (3v) and (3r) from a primary source, the laser light beams (5b.x), (5v. x) and (5r.x) of secondary source thus produced, must be made parallel again. To do this, each of the laser light beams (5b.x), (5v.x) and (5r.x) of secondary source is coupled with a bi-convex diopter (14x) designed to the dimension of the laser light beam (5b .x), (5v.x) and (5r. x) from a secondary source. In Figs 1, 2 and 3, a single bi-convex diopter is shown for each pixel (7x) for better clarity of the drawings. Next a

  manufacturing technique, the bi-convex dioptres (14x) are produced together on the same support with suitable characteristics as regards the refringence, the diotric power and the subtlety of the material. The idea is to directly shape the shape of a bi-

  convex (14x) or convex, by molding the support. According to the sixth step, the orientation of the laser broadcaster (1) not having its monitor facing the optical axis of the eyepiece of the observer, each of the laser light beams (5b.x), (5v.x) and (5r.x) of secondary source, is reflected by a set of mirrors (15) and (16) of planar or parabolic shape with an adapted setting, so that the laser light beams of secondary source (5b), (5v) and 30 (5r) central are merged with the optical axis of the observer's eyepiece. The laser light beams (5b.x), (5v.x) and (5r.x) of secondary source and parallel rays with regard to the final path are collimated towards the eyepiece so that the focus is located at around 35 from the center of the eye lens. In this case, the laser broadcaster (1) is supplemented by a global collimation diopter (2) convex or biconvex, of dioptric power calculated beforehand. The overall collimating diopter (2) concerned by its own thread mounting with external thread is coupled with the laser broadcaster S (1) by its thread mounting with internal thread and is removable from '' a movement of translation, from front to back, by a screw-nut system. The overall collimation diopter (2) is of a curvature calculated so that the focus of collimation is located in the center of the eye lens of the observer. Its function is to refract each laser beam from a secondary source of parallel rays produced by the laser broadcaster (1) towards the eyepiece. The overall collimation diopter (2) can be associated with other lenticular systems of different optical treatments, in order to correct or improve the vision of the image thus observed. After the sixth step, it follows that each of the laser beams (5b.x), (5v.x) and (5r.x) of secondary source converges according to its two-dimensional coordinates of the screen of the respective monitor. to (8G) and (8D) at a different angle of refraction at the incident point of the overall collimating diopter (2G) and (2D). Each (2G) and (2D) collimating diopter is associated with each eyepiece of the observer and focuses the laser beams from secondary sources (5b.x), (5v.x) and (5r.x) on the cells of the retina. Following the associated example of FIG. 2, this global collimation or this optical focusing of a different angle of refraction x for each of the laser light beams of secondary source (5b.x), (5v.x) and (5r. x) and symmetrical from one eyepiece to another, becomes representative in the visual field of the observer, of a binocular point of view object, provided that the respective image is placed in his eyepiece. Referring to fig. 2, the stereoscopic display device also includes FIG. 1, two laser broadcasters (1G) and (1D), two dioptres of

  global collimation (2G) and (2D) and a support frame.

  The laser broadcasters (1G) and (lD) being flat in shape, a frame quite distinct from these supports the entire stereoscopic viewing system. The support frame consists of two arms (19G) and (19D), each of them resting on one ear and fixed each of them, on each side to the mounts (9G) and (9D) of the laser broadcasters. (1G) and (lD). The mounts (9G) and (9D) of the laser broadcasters (1G) and (1D) are placed side by side and rest on the nose by a support tab (21). Each of the branches (19G) and (19D) can be folded over the mounts (9G) and (9D) of the laser broadcasters (1G) and (lD) by hinges of fasteners (20G) and (20D). The overall collimating dioptres (2G) and (2D) concerned by their own mount (18G) and (18D) with external thread thread are coupled respectively with the laser broadcasters (1G) and (lD) by their mount (9G ) and (9D) internal thread thread to be removable with a translational movement, from front to rear, relative to each of the 20 laser broadcasters (1G) and (ID) by a screw nut system. The diodes of global collimation (2G) and (2D) have the same characteristics as those explained in Fig. 1. The laser broadcasters (lG) and (lD) cannot be removed from the mounts (9G) and (9D) in a translational movement from front to back. On the other hand the laser broadcasters (1G) and (1D) can be removable with a lateral translation movement by an adjustment screw, in order to position each of the laser broadcasters (1G) and (lD) precisely facing its respective eyepiece OG and OD. With regard to what30) will follow each of the two laser broadcasters (1G) and (lD), the monitor (8) is composed on its matrix screen of light diffusion, of a mosaic of pixels (7.x) and (7.x) with semiconductor laser diodes (6b.x), (6v.x) and (6r.x). Each of the laser light beams (5b.x), (5v.x) and (5r.x) of secondary source emitted by each semiconductor laser diode (6b.x), (6v.x) and (6r.x) is perpendicular to the plane of the monitor (8) This requires a special arrangement of the semiconductor laser diodes (6b.x), (6v.x) and (6r.x) on the screen of their monitor (8) when they are produced. . The first four steps being canceled by the arrangement of all the semiconductor laser diodes (6b.x), (6v.x) and (6r.x) on their monitor (8), in the fifth step, the passage of primary source laser light beams, at the output of the emitting area of the semiconductor laser diodes (6b.x), (6v.x) 10 and (6r.x) being characterized by a light diffraction, the laser light beams (5b. x), (5v.x) and (5r.x), of secondary source thus produced by each of the laser diodes, are made again parallel. Each of the light beams (5b.x), (5v.x) and (5r.x) of secondary source15 is coupled with a bi-convex diopter (14r.x) (14v.x) and (14b.x) designed to the dimension of the laser light beam (5b.x), (5v.x) and (5r.x) from a secondary source. With regard to the sixth step, in this condition, the laser light beams (5b.x), (5v.x) and (5r.x) of central secondary source, are arranged in a direction parallel to the optical axis since their laser broadcaster (1) is directly close to the eyepiece. Each of the pixels (7x) of the monitor (8) emits laser light beams (5b.x), (5v.x) and (5r.x), in a direction 25 perpendicular to the plane of each of the monitor (8). The laser light beams (5b.x), (5v.x) and (5r.x), from secondary sources scattered parallel to each other are refracted by a global collimating diopter (2) towards the center of the ocular lens . Following this collimation of the laser light beams (5b.x), (5v.x) and (5r.x), from a secondary source the horizontal binocular scanning of the observer in his field of vision, always positions thanks to the collimation effect and whatever its line of sight, the OD and OG eyepieces on the optical path of the laser light beams of secondary source (5b.x), (5v.x) and (5r.x), coming from two pixels (7G.x) and (7D.x). All the laser light beams (5b.x), (5v.x) and (5r.x), are representative of a possible visual axis. All the laser light beams (5b.x), (5v.x) and (5r.x), each form a line of direction joining on the one hand any pixel point (7x) representative of an object point PO at point conjugated on the retina R'o. As a figurative example, a stereoscopic point of view is given by considering an object point PO of binocular viewing; represented by the parallax coordinates of two pixels (7G.8) of OG and (7D.2) of OD, each of them diffusing three laser light beams (5b.8), (5v.8) and (5r.8 ) for OG and (5b.2), (5v.2) and (5r.2) for OD, all passing through the respective visual axis of ocular OG or OD according to their convergence, by collimation or refraction. 15 According to a variant of embodiment of FIG. 2 the monitor (8) according to FIG. 3 can be realized, according to a form of parabolic bending. In this embodiment, a global collimation diopter (2) for each the broadcaster (1) is useless since the curvature of the monitor 20 (8) is collimator. Each of the laser diodes (6b.x) (6v.x) (6r.x) of each of the pixels (7.x) and respectively to the parabolic monitor (8) are arranged with their light emitting area perpendicular to the curvilinear plane of the parabolic monitor (8). In other words, the emitting area of the laser diodes is oriented towards the focus of the parabolic monitor. The parabolic monitor (8) is calculated beforehand of its curvature so that the focus of collimation is located in the center of the eye lens of the observer. The advantage of this embodiment lies in the lightness of the whole stereoscopic display system as well as in recognized ergonomics and aesthetics. The laser broadcasters (1G) and (1D) can be removable from their own mount (9G) and (9D) by sliding them in a translational movement from front to back, by coupling the two laser broadcasters (1G) and (ID) with an adjustment screw (22) whose nut merges into the body of the support tab (21). Just as the laser broadcasters (1G) and (1D) can be removable with a lateral translational movement to position them facing the eyepieces.5 The glabal collimation system, whatever its embodiment, must be implemented so that the laser beams of secondary source do not cross each other perfectly at the same ocular point of the observer, this for a question of rise in temperature at the crossover points. For an emmetropic eye, the naturally induced and artificially accentuated optical aberrations should be enough to avoid such light concentration. According to a variant embodiment not explained by a figure, the pixels (7.x) are designed, according to two different types of chromatic couple, each respective type to a laser broadcaster (1G) or (1D), with pixels (7G). x) with semiconductor laser diodes (6b) and (6v) for one, and with pixels (7D.x) with semiconductor laser diodes (6v) 2 () and (6r) for the other. This type of configuration responds to the stereoscopic visualization technique based on the anaglyph and offers less bulky technical means of production. In addition, this technique is used in the design of computer stereoscopic images to save memory. This stereoscopic display device can be attached directly to the management of a computer for the observation and exploitation of virtual images. According to a variant of the chromatic light scattering concerning the alternative embodiment of pixels30 explained just above, a chromatic sequential video inverter, orders several times per second, the inversion of the chromatic sequences on the video matrix circuits of the screens of each of the two monitors (8G) and (8D). The chromatic sequences are the blue-green sequence and the green-red sequence. For a given monitor (8G) or (8D) and attached to an eyepiece, it diffuses sometimes in blue-green light, and sometimes in green-red light. However, a computer program for reversing video sequences on a computer can replace the chromatic sequential video inverter if the stereoscopic display device is attached to a computer. This variant embodiment with sequential inversions of the chromatic modes, preserves a

  good receptivity to the light response of all types of retinal cells for both eyes at the same time, in order to avoid any residual conditional perception effect10 (Mc Collough effect).

  This stereoscopic visualization system is particularly intended for spatio-temporal displacements

  of a user by simulating virtual images; to become a real substitute for computer monitors or portable mini-TVs.

Claims (3)

Claims 1) Stereoscopic display device comprising respectively for each of the OG and OD eyepieces two laser broadcasters (1G) and (ID) identical in all points, and relative to a laser broadcaster (1G) or (LD), the latter being able to comprise according to conditions of the optical path of several laser beams from primary source (3b), (3v) and (3r) of production towards the eyepiece of the observer, several elements arranged successively in six stages characterized in that the laser broadcaster ( 1) comprises, in its rear part, a set of three semiconductor laser diodes (4b), (4v) and (4r) of primary light production source monochrome blue, green, or red. 2) Stereoscopic display device according to claim 1 characterized in that the laser broadcaster (1) is supplemented by a global collimation diopter (2) convex or biconvex. 3) A stereoscopic display device according to claim 1 characterized in that in the first step, the laser light beams (3b), (3v) and (3r) of primary source are diffracted at a greater angle O by coupling the light beams lasers (3b) and (3v) from primary source on two concave diopters (llb) and (11v) and by reflecting the laser light beam (3r) from primary source with a convex mirror (10r). 4) A stereoscopic display device according to claim 1 characterized in that in the second step the laser light beams (3v) and (3r) of primary source are reflected at an angle adapted by two mirrors with unidirectional reflection (12v) and (12r ) of planar shape and themselves traversed by the laser light beam (3b) being disposed thereof perpendicular to the righting diopter (13). 5) stereoscopic display device according to claim 1 characterized in that in the third step each of the laser light beams (3b), (3v) and (3r) of primary source is coupled with a bi-convex diopter (13) of diameter equal to the diagonal of a monitor and itself respective to the coupling of the three laser light beams (3b), (3v) and (3r) from primary source. 6) A stereoscopic display device according to claim 1 characterized in that in the fourth step each of the laser light beams (3b), (3v) and (3r) of respective primary source to a chrominance is coupled with a monitor (8) to LCD active cell liquid crystal cells by substituting the laser light beams (3b), (3v) 20 (and (3r) from primary source for all of the LED luminescent diodes. 7) Stereoscopic display device according to claim 1 characterized in that in the fifth step each of the laser light beams (5b.x), (5v.x) and (5r.x) of secondary source is coupled with a bi-convex diopter (14x) designed to the dimension of the light beam laser (5b.x), (5v.x) and (5r.x) from secondary source. ) Stereoscopic display device according to claim 1 characterized in that in the sixth step each of the laser light beams (5b.x), (5v.x) and (5r.x) of secondary source, is reflected by a set of mirrors (15) and (16) of planar or parabolic shape with a suitable adjustment, so that the laser beams of secondary source (5b), (5v) and (5r) central is merged with the optical axis of l eye of the observer. 9) A stereoscopic display device according to claim 6 characterized in that the monitor (8) can be composed on its matrix screen of light diffusion, of a mosaic of pixels (7.x) and (7.x) with laser diodes semiconductor (6b.x), (6v.x) and (6r.x).   1) 10) stereoscopic display device according to claim 6 characterized in that   According to an alternative embodiment of FIG. 2 the monitor (8) according to FIG. 3, can be achieved, according to a form of parabolic bending.