PROJECTION TELEVISIONS COIM THREE-DIMENSIONAL HOLOGRAPHIC SCREENS Background of the Invention 1. Field of the Invention This invention relates generally to the field of television projection receivers, and in particular, to television projection receivers having screens that provide a color shift significantly reduced and / or cabinet depth significantly reduced. 2. Description of the prior art The color shift is defined as the change in the red / blue or green / blue ratio of a white image formed in the center of a projection screen by projected images of red, green and green projection tubes. blue, when observed at different angles in the horizontal plane, by observations made in the vertical viewing angle of peak brightness. The problem of color shift is caused by the need for at least three image projectors for respective images of different colors, for example, red, blue and green. A projection screen receives images from at least three projectors on a first side and displays the images on a second side with controlled light scattering of all the displayed images. One of the projectors, usually green and usually in the center of a projector array, has a first optical path in an orientation substantially orthogonal to the screen. At least two of the projectors, usually red and blue and usually placed on opposite sides of the green central projector in the array, have respective optical paths converging towards the first optical path in a non-orthogonal orientation defining incident angles. The color shift results from the non-orthogonal relationship of the red and blue projectors, in relation to the screen and the green projector. As a result of the color shift, the color tones may be different in each position on the screen. The condition in which the difference in color tone is large is generally referred to as bad white uniformity. The smaller the color shift, the better the uniformity of white. The color shift is denoted by a number scale, in which the smaller numbers indicate less color shift and better white uniformity. According to a common procedure, the values for the red, green and blue luminance are measured in the center of the screen from a variety of horizontal viewing angles, commonly at least about -40 ° to + 40 °, up to about -60 ° to + 60 °, in increments of 5 ° or 10 °. The positive and negative angles represent horizontal viewing angles to the right and left of the center of the screen respectively. These measurements are taken at the peak vertical viewing angle. The red, green, and blue data are normalized to unity at 0 °. One or both of the following equations (I) and (II) are evaluated at each angle: (I) C (?) = 20-log10 ((red (?) / (Blue (?)); And, (II) C (?) = 20-log10 ((green (?) / (Blue (?)), Where? Is any angle within a range of horizontal viewing angles, C (?) Is the color shift in the angle? , red (?) is the luminance level of red in the angle?, blue (?) is the level of luminance of blue in the angle? and green (?) is the level of luminance of green in the angle?. Maximum of these values is the color shift of the screen.In general, the color shift should not be greater than 5 nominally, in any commercially acceptable screen design.Other engineering and design constraints may sometimes require that the displacement of color is a bit greater than 5, although said color shift performance is undesirable and usually causes a lower perception image with poor white uniformity. As for television projection receivers are generally manufactured by an extrusion process that uses one or more molding rolls to configure the surface of a thermoplastic sheet material. The configuration is usually an array of lenticular elements, also called lenticules and contact lenses. The lenticular elements may be formed on one or both sides of the same sheet material or only on one side of different sheets which may then be permanently combined as a laminated unit or otherwise mounted adjacent thereto to function as a laminated unit. In many designs, one of the surfaces of the screen is configured as a Fresnel lens to provide light diffusion. The prior art efforts to reduce color shift and improve white uniformity have focused exclusively on two aspects of the screen. One aspect is the shape and arrangement of the lenticular elements. The other aspect is the degree to which the screen material, or portions thereof, are added with light diffusing particles to control the diffusion of light. These efforts are exemplified by the following patent documents. In U.S. Patent Serial Number 4,432,010 and in U.S. Patent Serial Number 4,536,056, a projection screen includes a light-transmitting lenticular sheet having an inlet surface and a surface of exit. The entrance surface is characterized by horizontal diffusion lenticular profiles that have a ratio of a lenticular depth Xv to a radius of curvature of the closed axis R 1 (Xv / R1) that is within the range of 0.5 to 1 .8. the profiles are elongated along the optical axis and form spherical entry lenticular lenses. The use of the screen with a double-sided lenticular lens is common. Such a screen has cylindrical input lenticular elements on an input surface of the screen, cylindrical lenticular elements formed on an output surface of the screen and a light-absorbing layer formed on the non-converging part of the light surface of the screen surface. departure. Each of the input and output lenticular elements has the form of a circle, ellipse or hyperbola represented by the following equation (III): (lll) Z (x) = (Cx2) / (1 + [1 - (K + 1 ) C2x2] 1 2) where C is a principal curvature and K is a conical constant. Alternatively, the lenses have a curve to which a term with an order greater than 2d0 order has been added. In screens that make use of a double-sided lenticular lens, it has been proposed to specify the positional relationship between the input lens and the output lens, or the lenticular elements that make up the lenses. It has been disclosed, for example in the United States Patent Serial Number 4,443,814, to place the input lens and the output lens in such a way that the lens surface of one lens is present at the focal point of another lens. . It has also been disclosed, for example in Japanese Patent Serial No. 58-59436, that the eccentricity of the input lens is substantially the same as the reciprocal of the refractive index of the material constituting the lenticular lens. It has further been taught, for example in U.S. Patent Serial Number 4, 502,755, to combine two sheets of double-sided lenticular lenses so that the planes of the optical axes of the respective lenticular lenses are angled. straight with respect to each other, and forming such double lens lenticular lenses so that the input lens and the output lens at the periphery of one of the lenses are asymmetric with respect to the optical axes. It has also been taught, in U.S. Patent Serial Number 4,953,948, that the position of the convergence of light only in the valley of an input lens must be diverted to the viewing side of the surface of a lens output so that the tolerance for misalignment of optical axes and the difference in thickness can be made larger or the color shift can be made smaller. In addition to the various proposals to decrease the color shift or non-uniformity of white, other proposals to improve the performance of projection screens are directed towards the brilliance of images and to ensure the appropriate visual fields in both directions, horizontal and vertical. Such techniques are not of direct interest and are not described in detail. A summary of many such proposals can be found in U.S. Patent Serial Number 5, 196, 960, which shows a double-sided lenticular lens sheet comprising an input lens layer having a lens of input, and an output lens layer having an output lens, whose lens surface is formed at the point of light convergence of the input lens, or in the vicinity thereof, wherein the input lens layer and the output lens layer are each formed of a substantially transparent thermoplastic resin and at least the output layer contains fine particles of light diffusion and where there is a difference in the light diffusion properties between the lens layer input and the output lens layer. A plurality of input lenses comprise a cylindrical lens. The output lens is formed of a plurality of output lens layers, each having a lens surface at the point of light convergence of each lens of the input lens layer, or in the vicinity thereof. A light absorbing layer is also formed in the non-convergent part of light of the output lens layer. This screen design is said to provide sufficient horizontal visual field angle, decreased color shift and a brighter image, as well as easy fabrication through extrusion processes. Despite several years of aggressive developments in the design of projection screens, the improvements have been incremental, at best. Moreover, there has been no success in exceeding certain benchmarks. The angle of incidence defined by the geometric arrangement of the image projectors, here referred to as angle a, has generally been limited to the range of greater than 0 ° and less than or equal to approximately 10 ° or 1 1 °. The size of the image projectors makes the angles of a close to 0 ° essentially impossible. In the range of angles of a less than about 10 ° or 1 1 °, the best performance of the color shift that has been achieved is approximately 5, as determined in accordance with equations (I) and (II) . In the range of the angles of o- greater than about 10 ° or 1 1 °, the best performance of the color shift that has been achieved is not commercially acceptable. In fact, television projection receivers that have angles of a greater than 10 ° or 1 1 ° are not known. The small angles of a have a significant and undesirable consequence, especially the very large cabinet depth needed to house a television projection receiver. The large depth is a direct result of the need to accommodate optical trajectories that have small incidence angles (a). Techniques for reducing the size of television projection cabinets are generally based on mirror arrays. Such efforts are also ultimately limited by the small range of incidence angles. Polaroid Corporation sells a photographic polymer called DMP-128®, which Polaroid Corporation can manufacture as a three-dimensional hologram, using patented processes. The holographic manufacturing process is described, in part, in U.S. Patent Serial Number 5, 576,853. A three-dimensional holographic screen for a projection television was proposed by Polaroid Corporation, as one of many suggestions made during the efforts to establish a market for the holographic polymer photographic product DMP-128®. The proposal was based on advantages that Polaroid Corporation expected in terms of greater brilliance and resolution, lower manufacturing cost, lower weight, and abrasion resistance to which two-piece screens were attached during shipment. Polaroid Corporation never proposed a particular holographic configuration for holographic volume elements that could function as a holographic television projection screen, and never even considered the problem of color shifting on television projection screens of any type, holographic or any other . Above all, despite years of intense development to provide a television projection receiver that has a screen with a color offset of less than 5, still significantly less than 5, or that has a color shift as low as 5 for viewing angles. At even greater than 10 ° or 11 °, there has been no progress in solving the problem of the displacement of color other than those incremental changes in the shapes and positions of the lenticular elements and diffusers in the conventional projection screen. Moreover, despite suggestions that three-dimensional holograms can be useful for projection screens, although for reasons that have nothing to do with color shifting, there has been no effort to provide projection televisions with three-dimensional holographic screens . A deep sense of need for a television projection receiver that has significantly improved color displacement performance, which can also be built in a significantly smaller cabinet, still remains unsatisfied. Brief Description of the Invention A television projection receiver in accordance with the embodiments of the invention described herein provides a significant improvement in color shift performance, measured in orders of magnitude, such that a color shift of 2 or less it can be achieved with television projection receivers that have angles of incidence a in the range of less than 10 ° or 1 1 °. Moreover, the color shift performance is so significant that commercially acceptable television projection receivers having angles of incidence greater than about 30 ° can be provided in much smaller cabinets. The color shift performance of such wide-angle receivers is at least as good as small-angle receivers, for example having a color shift of 5, and one can expect to approximate or even achieve values as low as approximately 2, as in the receivers from angle to small. These results are achieved by completely abandoning the extruded lens screen technology. Instead of this, a television projection receiver according to an arrangement of the invention has a screen formed by a three-dimensional hologram formed on a substrate, for example, a polyethylene film, such as Mylar®. Such a three-dimensional holographic screen was originally developed for its expected advantages in terms of higher brightness and resolution, lower manufacturing cost, lower weight, and abrasion resistance to which two-piece screens were subject, for example during shipment. The discovery of the color shift performance of the three-dimensional holographic screen came approximately when it was tested to determine if the optical properties of the three-dimensional screen would be at least as good as those of a conventional screen. The performance of the color shift of the three-dimensional holographic screen, as measured by equations (1) and (I I), was so unexpectedly low that it caused concussion. The barriers limiting the improvement of the prior art to incremental steps have been completely eliminated. Moreover, smaller cabinets with projection geometry characterized by larger incident angles can now be developed. A projection television that has the unexpected properties associated with three-dimensional holographic screens, and in accordance with the embodiments of the invention described herein, comprises: at least three image projectors for the respective images of the different colors; a projection screen formed by a three-dimensional hologram device on a substrate, the screen that receives images of the projectors on a first side and that displays the images on a second side with controlled light scattering of all the images displayed; one of the projectors having a first optical path in a substantially orthogonal orientation with the screen and at least two of the projectors having respective optical paths converging towards the first optical path in a non-orthogonal orientation defining angles of incidence; and, the three-dimensional hologram representing a three-dimensional array of lenticular elements having an effective configuration for reducing the color shift in the displayed images, the screen having a color shift less than or equal to approximately 5 for all incident angles in a range greater than 0 ° and less than or equal to approximately 30 °, as determined by the maximum value obtained from at least one of the following expressions: C (?) = 20-log? or ((red (?) / (blue (?)); and, C (?) = 20- log10 ((green (?) / (blue (?)), where? is any angle within a range of angles of horizontal vision, C (?) is the color shift in the angle?, red (?) is the luminance level of red in the angle?, blue (?) is the level of luminance of blue in the angle? and green (?) is the luminance level of green in the angle? The color shift of the screen can be expected to be less than 5, for example, less than or equal to about 4, 3 or even 2. In terms of the known barrier at an angle of incidence of approximately 10 ° or 1 1 °, the color shift of the screen is less than or equal to approximately 2 for all angles of incidence in a first subrange of angles of incidence greater than 0 ° and less than or equal to about 10 °, and, the color shift of the screen is less than or equal to about 5 for all incident angles in a second subrange of angles of incidence greater than about 10 ° and less than or equal to about 30 °. The screen additionally comprises a light transmission reinforcing member, for example, of an acrylic material in a layer having a thickness in the range of about 2-4 mm. The substrate comprises a highly durable, transparent, water repellent film, such as a polyethylene terephthalate resin film. The substrate can be a film having a thickness in the range of about 25.4-254 microns. A thickness of approximately 178 microns has been found to provide adequate support for the three-dimensional hologram. The thickness of the film is not related to performance. The three-dimensional hologram has a thickness in the range of no more than about 20 microns. The projection television may additionally comprise one or more mirrors between the image projectors and the screen. Brief Description of the Drawings Figure 1 is a representative diagram of a projection television according to the embodiments of the invention described herein. Figure 2 is a simplified diagram of the geometrically useful projection television to explain the embodiments of the invention. Figure 3 is a side elevational view of a reinforced projection screen according to the embodiments of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A 1 0 television projection receiver is illustrated in the form of a diagram in FIG. 1. A matrix 12 of cathode ray tubes 14, 16 and 1 8 provides red, green and blue images, respectively. The cathode ray tubes are provided with the respective lenses 1 5, 1 7 and 1 9. The projected images are reflected by a mirror 20 on a projection screen 22. Additional mirrors can also be used., depending on the particular geometry of the optical paths. The green cathode ray tube 16 projects the green image along an optical path 32, which has a substantially orthogonal orientation to the screen 22. In other words, the optical path is at a right angle to the screen. The red and blue cathode ray tubes have respective optical paths 34 and 36, which converge towards the first optical path 32 in a non-orthogonal orientation defining angles of incidence a. The incidence angles introduce the problem of color displacement. The screen 22 comprises a three-dimensional hologram 26 arranged on a substrate 24. The screen receives images of the projectors on a first, input surface side 28 and displays the images on a second, output surface side 30, with light scattering controlled of all the images displayed. The substrate is preferably an extremely durable, transparent, water repellent film, such as a polyethylene terephthalate resin film. Such a movie is available from E. I. du Pont de Nemours &; Co. under the Mylar® trademark. The film substrate has a thickness in the range of about 25.4-254 microns. It has been found that a film having a thickness of approximately 178 microns provides adequate support for the three-dimensional hologram disposed therein. The thickness of the film does not affect the performance of the screen in general or the performance of the color t in particular, and films of different thicknesses may be used. The three-dimensional hologram 26 has a thickness of no more than about 20 microns. Three-dimensional holographic screens are available from at least two sources. Polaroid Corporation uses a patented wet chemical process to form three-dimensional holograms in its DMP-128 photo polymeric material. A preferred embodiment of the three-dimensional holographic screens used in the television projection receivers described and claimed herein was manufactured by the wet chemical process of Polaroid Corporation, in accordance with the following performance specifications: Horizontal half-angle of view: 38 ° + 3 °, Vertical half-angle of view: 10 ° + 1 °, Screen gain: > . 8, Color t: < . 3, where the horizontal and vertical viewing angles are measured conventionally, the screen gain is the quotient of the intensity of the light directed from the source towards the back of the viewing surface, and the intensity of the light of the part front of the viewing surface towards the observer, measured orthogonal to the screen, and the color t is measured as described above. The extraordinary performance of the color t of the three-dimensional holographic projection screen was, as explained in the Brief Description of the Invention, totally unexpected. Figure 2 is a simplified diagram of a projection television, which omits the mirror and lenses, to explain the performance of the color t. The optical axes 34 and 36 of the red and blue cathode ray tubes 14 and 18 are aligned symmetrically at angles of incidence with respect to the optical axis 32 of the green cathode ray tube 16. The minimum depth D of a cabinet is determined by the distance between the screen 22 and the trailing edges of the cathode ray tubes. It will be appreciated that, as the angle a becomes smaller, the cathode tubes move closer together, and must be further spaced from the screen to prevent them from colliding with each other. At a sufficiently small angle, such interference can not be avoided. This undesirably increases the minimum depth D of a cabinet. Conversely, as the angle a becomes larger, the cathode ray tubes can move closer to the screen 22, reducing the minimum depth D of a cabinet. On the viewing side of the screen 22, two horizontal half-viewing angles are designated by -β and + β. Together, a total horizontal viewing angle of 2ß is defined. The half-vision angles may typically be within the range of + _ 40 ° to + 60 °. Within each half angle is a plurality of specific angles?, In which the color t can be measured and determined, in accordance with equations (I) and (II) explained above. In terms of the known barrier at an angle of incidence of about 10 ° or 1 1 °, the color t of the three-dimensional holographic screen is less than or equal to about 2 for all angles of incidence in a first subrange of incident angles greater than 0 ° and less than or equal to approximately 10 °; and, the color t of the screen is less than or equal to about 5 for all incident angles in a second subrange of incident angles greater than about 10 ° and less than or equal to about 30 °. A color t less than or equal to approximately 2 is expected, as in the first subrange, can also be achieved in the second subrange of larger incident angles. With reference to Figure 3, the substrate 24 comprises a transparent film, such as Mylar®, as described above. The photographic polymeric material from which the three-dimensional hologram 26 is formed is supported on the film layer 24. A suitable photographic polymer material is the DMP-128®. The screen 22 may additionally comprise a light transmission strengthening member 38, for example, of an acrylic material, such as polymethylmethacrylate (PMMA). Polycarbonate materials can also be used. The reinforcing member 38 is currently a layer having a thickness in the range of about 2-4 mm. The screen 22 and the reinforcing member are adhered to one another along the entire mutual boundary 40 of the holographic layer 26 and the reinforcing member 38. Adhesive, radiation and / or thermal bonding techniques can be used. The surface 42 of the reinforcement layer can also be treated, for example by one or more of the following: coloration, anti-reflective coatings, anti-scratch coatings. Various surfaces of the screen and / or its constituent layers can be provided with other optical lenses or lenticular arrays to control aspects of the projection screen that exhibit performance characteristics different from the performance of the color shift, as is known to be done with the conventional projection screens, without deteriorating the performance of the improved color shift of the three-dimensional holographic projection screen.