IMAGE PROJECTION APPARATUS

Abstract: A projected image displaying apparatus for displaying bright three-dimensional images on a display screen. In one embodiment, images in three colors, each in the form of vertically oriented stripes, are projected onto a transmissive diffusion surface with the stripes of the three images interleaved with one another, and preferably slightly over­ lapping one another. A lenticular lens may be employed to direct the three dimensional image to the eyes of the viewer. In another embodiment, the two-dimensional images are projected in a form of three energy beams, which may be infrared, ultraviolet or visible light, onto a light-emitting layer composed of repeating sequences of first through third phosphor stripes, each corresponding to one of the primary colors.

Description: IMAGE PROJECTION APPARATUS BACkGROUND OF THE IWNTION The present invention relates generally to an image projection apparatus, and more particularly to a three-dimensional image displaying apparatus capable of displaying *-hree-dimensional images on a screen. With the advance of information transmission in the form of gets, there has been a strong demand in recent years to display images on a large-size screen, and an image projection apparatus have been developed to meet such a demand. The image projection apparatus utilizes, for example, three cathode-ray tubes for producing three pr imarycolor images and includes an optical system for projecting the primary-color images at an enlarged scale onto the screen so that an enlarged image is produced in color by combining the three primary-color images on the screen. In this image projection apparatus, the brightness of the displayed image is determined by the brightness of the image displayed on each cathode-ray tubet and it is difficult to obtain a bright image on a large screen. The prior art image projection apparatus, therefore, has a drawback in that the illumination in the room should be turned down for viewing. Further, in a conventional three-dimensional image displaying apparatus, special eyeglasses have been required to view displayed images. According to one system, polarizers having directionsz of polarization displaced 90 degrees from each other are place8 in front of two image display tubes for left and right eyes, the two images are combined with a half-silvered mirror, and the viewer views the combined image through eyeglasses having mutually orthogonal directions of polarization. In another system, one image display tube alternately displays images tor lett and right eyes in successive fields, and shatters are provided for alternately shielding the left and right eyes in synchron ization with the alternate display of images. Still another system includes one image display tube for displaying the red and blue components of a color image and one for displaying the green component of the image, and eyeglasses are provided having a filter passing red and blue light for the left lens and a filter passing green light for the right lens. These three-aftaensional television systems which require special eyeglasses are disadvantageous in that displayed images suffer from appreciable flickering and the viewer may suffer from eye fatigue after viewing such a display over a long period of tine. Figs. 1 and 2 of the accompanying dravings illustrate a three-dimensional image displaying apparatus which has been proposed to dispense with special eyegla3sco* The illustrated system has been described by Takanori Ohkoshi, Three-Dimensional Isnaqe llnnineering, Japans Sangyo Tosho Co., Ltd., 1972, pp. 217, 218. In Fig. 1, images displayed by an image tube S for the left eye and an image tube 6 for the right eye are combined by a half-silvered mirror 2, and the combined image is viewed from a viewing point 1. A double-layer slit plate as shown in Fig. 2A, or a combining of a slit plate and a lenticular lens as shown in Fig. 2B, is placed in each of positions 3 and 4 With this arrangement1 the right eye views an image on the tube 5 and the left eye views an image on the tube 6. Further in Figs. 2A and 2B, reference numerals 7 and 16 designate shield plates compose8 of vertical stripes, 8 indicates an image display surface, and 9 a lenticular lens. The construction of Fig, 2A is not preferable since images are divided into vertical atripea, The arrangement of Fig, 2B is somewhat better as it does not suffer from such problems, Both systems, however, have a drawback that since images ate combined by a halfE-silvered mirror 2, the image position is far to the rear. In still another known three-dimensional image displaying apparatus, the slit plate 7 shown in Fig. 2A or the lenticular lens 9 shown in Fig. 2B is placed immediately in front of a reflecting screen, and an image is projected onto the screen by two or more projectors, with two projectors, however, the range in which the images can be observed is small. Ons known screen capable of transmitting light therethrough has two lenticular lenses disposed back to back with a diffusion surface interposed therebetween. Such a screen is disclosed by Gen Yanagisawa, history of Three-nimensional Television and Its Various Systems", Graphics and Images, spring 1982, p. 86 see especially Figs. 21-a and 21-b. With this system, an image is projected from a projector onto a diffusion surface and the transmitted light is viewed. The difficulty with this system is that the range in which three-dimensional images can be viewed is small. Widening the viewing range requires many projectors and results in a system of large physical size. There is known a still further system, disclosed in i:xatined Japanese Patent Publication No. 57-11550, in which a special three-dimensional television picture tube is employed for displaying three-dimensional images. The picture tube required is, however, of a special and complex construction. SUMMARY OF THE INVENTION Accorclingly, it is an object of the invention to provide an image projection apparatus capable of producing bright three-dimensional images. It is a further object of the invention to provide such an image projection apparatus in which the image can be viewed over a relatively wide range of viewing angles. In acoordance with the above and other objects of the invention, there is provided a projected image displaying apparatus including image source means and image displaying meana, with the image source means being used to optimally protect two-dimensional images onto the image displaying means. The image displaying means includes, in one preferred embodiment, a transmissive diffusion surface onto which images produced by the image source means are projected, a shield plate composed of a plurality of vertically oriented stripes disposed on a side of the transmission diffusion surface adjacently image source means tor projecting the images onto the transtnissive diffusion surface in the form of overlapping, interleaved stripes, and a lenticular lens disposed on the side of the transmissive diffusion surface opposite the image source means. In another preferred embodiment, the image source means comprises means for projecting first through third energy beams representing images of the three primary colors, red, green and blue. In this embodiment, the image displaying means includes a substrate capable of transmitting light therethrougb, a light-emitting layer disposed on the substrate, and a shield plate of the type described above spaced Erc)m the light-emitting layer for directing the energy beams corresponding to images in the three primary colors from the image source means onto the light-emittlng layer in luch a manner as to maintain the projected beams interleaved with one another on the lightemitting layer. The light-emitting layer includes a plurality af each of first through third phosphor stripes receptive of the respective first through third energy beams with the first through third stripes being arranged parallel to one another in repetitive sequences. BRIEF DESCRIPTION OF THR DRAWINGS Fig. 1 is a view showing the arrangement of a conventional three-dimensional television display apparatus; Figs. 2A and 2B are, respectively, views of a slit plate and lenticular lens plate, placed directly in front of a display surface of the conventional display apparatus; Fig. 3 shows a three-dimensional television display apparatus constructed according to a preferred owhodiment of the present invention; Fig. 4 is a perspective view of B screen for displaying three-dimensional images in the three-dimensional television display apparatus shown in Fig. 3; Figs. 5 and 6 show modified screens for displaying three-dimensional images; ; Fig. 7 shows a phosphor screen of a projection image tube constructed according to another embodiment of the present invention; Fig. B is a pret of views illustrating a threedimensional image display apparatus for displaying colored three-dimensional images according to still another embodiment of the present invention; Fig. 9 is a plan view of a projection television apparatus according to a further embodiment of the present invention; Fig. 10 is a fragmentary enlarged cross-sectional view of a screen of the projection television apparatus shown in Pig. 9, Pig, 11 is a fragmentary elevational view showing a screen according to still another embodiment; ; Fig. 12 is a fragmentary cross-sectional view of a screen of the projection telavlsion apparatus according to a todification of the embodiment shown in Pig. 9 and 10; Fig. 13 shows a modification of the screen shown in Fig. 12; and Fig. 14A and 14H are fragmentary elevational view showing screens shown in Fig. 12 or 13. DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will hereinafter be described in detail with reference to the drawings. Figs 1, 2A and 2B show a conventional threedimensional television system as described above The slit plate or lenticular lens plate as shown in Fig. 2A or 2B is places in each of the positions 3 and 4 illuatrated in Fig. 1. The surface R or 10 le positioned in overlapping relation to the image display surfaces of the image tubes 5 and 6. As mentioned above, the prior art system as illustrated is disadvantageous in that a displayed image appears positioned to the rear. Also, it may be mentioned that the screen is relatively dark since the viewer vies only light that has been transmitted through the halfsilvered mirror, Pig 3 is a view illustrative of the principles of a three-dimensional display apparatus sccording to a first preferred embodiment of the present invention. Designated at 11 is the position Of the left eye of a viewer and at 12 the position of the right eye of the viewer. An image displayed by a projection image tube 20 il directed by a lens 19 to a shield plate 16 having vertical stripes. The image is then projected onto a diffusion surface 15. Similarly, an image displayed by a projection image tube 22 is directed by a lens 21 to the vertically striped shield plate 16, and is then projected onto the diffusion surface 15, The image for the left eye, which is produced by the projection image tube 20, is projected onto the diffusion surface 15 in the vicinity of an area 17 thereof, while the image for the left eye, which i8 produced by the projection image tube 22, is projected onto the diffusion surface 15 in the vicinity of an area 18 thereof, with the stripes of the two images being interleaved. The images having passed through the diffusion surface 15 are separated by a lenticular lens 14 into an image which can be viewed in the direction of the viewer' right eye 12 and an image which oan be viewed in the direction of the viewer's right eye 11. More specifically, the image in the vicinity of the area 17 of the diffusion surtace 15 is projected in the direction of the left eye 11 while the image in the vicinity of the area 18 of the diffusion surface 15 is projected in the direction of the right eye 12. Thus, the two imagea can be viewed as a three-dimensional image. The lenticular lens plate 14, the diffusion surface 15, and the vertically striped shield plate 16 jointly constitute a three-dimensional image screen 13. Fig. 4 is a perspective view showing the threedimensional image screen 13 of Pig. 3 in greater detail. With such an arrangement, the images from the projection image tubes 20 and 22 are projected onto the diffusion surface 15 as interleaved vertical stripes. The image stripes should preferably have some overlap. With this construction, the displayed three-dimensional image can be viewed even if the viewer moves laterally a small distance, and hence the range in which images can be seen is widened. When the viewer moves to the tight, the three dimen4ional image being viewed appears to be shifted to the left, and when the viewer moves to the left, the three dlmensional image being viewed appears to be shifted to the right, which is usually not objectionable. With the construction of Fig. 3, if the screen 13 is relatively large in size, the image on the diffusion surface in lateral peripheral edge portions ot the screen appears slightly shifted outwardly in position, and the incident angles of light rays emitted from the projection image tubes 20 and 22 falling on the screen in such lateral peripheral edge portions are angularly shifted. This reduces the quantity of light reaching the viewer, resulting in a so-called shading phenomenon. Such shading can be reduced by placing a Fresnel lens 23 (Fig. n in front of or behind the vertically striped shield plate 16. Fig. 5 shows the Fresnel lens 23 as being positioned in front of the shield plate l6. Fig. 6 illustrates a diffusion surface 24 arranged such that a displayed three-dimensional image will not appear inverted when it is viewed at in a lateral direction rather than head on. The arrangement of Fig. 6 has been proposed by Japanese Laid-Open Patent publication NO. 5096228. Other proposals for preventing three-dimensional ires from appearing inverted .are disclosed in Examined Japanese Utility Model Publication No. 51-213 and Japanese Laid-Open Patent Publications sNo. 50-96227. The oonctruction of the diffusion surface per sg, however, is not part of the present invention. Fig. 7 shows a three-dimensional image display apparatus according to another embodiment of the present invention More specifically, Fig. 7 illustrates a phosphor screen 26 of a projection image tube corresponding to the projection image tube 20 or 22 shown in Fig. 3. While the phosphor screen illustrated in Fig. 3 eatts light over its entire surface, the phosphor screen of Fig. 7 is composed of vertical stripes 28 which emit light separated by vertical stripes 27 which emit no light. This arrangement is effected by a uniform phosphor screen 26 and a vertically striped shield plate 25 positioned directly in front of the phoaphor screen 26. Accordingly, a vertically striped image is produced. Images from the left-eye and right-eye image tubes are projected onto the diffusion surface 15 in overlapping interleaved stripes, as described before. With this embodiiaent, no shield plate 16 as shown in Pigs, 3 and 4 is required. Rather than plaeing the shield plate iminodiately in front of the phosphor screen 26 as shown in Fig. it, a vertically striped electrode may be provided for shleldinq the electron beas falling on the phosphor screen 26. With such an arrangement, the portions indicated by 27 in Fig. 7 contain luminescent phosphor but emit no light. The manner in which images are projected onto the diffusion surface 15 remains ag described above. As another arrangement for implementing the embodiment of Fig. 7, a beam blanking process can be employed whereby the electron beam which scans the phosphor screen 26 is periodically cut off by an external circuit for producing a vertically striped image. This process is also capable of producing vertically striped left-eye and righteye images which can be projected onto the diffusion surface 15 in the desired overlapping, interleaved pattern. Any of the arrangements described above allow the viewer to observe a three-dimensional image at the viewing points 11 and 12, The present invention is not to be interpreted as being limited to the foregoing embodiments, but includes various modifications. Three-dimensional images can be viewed in color by employing color image tubes instead of monochrome image tubes as the projection image tubes 20 and 22. For achieving a three-dimensional color television display apparatus, it would be a simple matter to use color image tubes for the projection image tubes 20 and 22 shown in Fig. 3 However, no projection image tube is generally available at the present time which is capable of displaying images in colors. Three-dimensional images can be displayed in color by the system shown in Figs, SA and 8B. More specifically, the ararangement of Big. SA is similar to that of Fig. 3, but differs therefrom in that color filters 31 and 34 are added. .Fig. 8A is a plan view of this sytem, while Fig. 8B is a side elevational view. As shown ln Fig. 8B, a projection image tube 36 emits red light which is projected through a projection lens 35 and a red-pass filter 34 onto a diffusion surface 15. A projection image tube 39, a projection lens 38, and a green-pass filter 37 serve to project green light onto the diffusion surface 15. Likewise, a projection image tube 42, a projection lens 41, and a blue-pass filter 42 serve to project green light onto the diffusion surface 15 The projection image tubes and related components shown in Fig. SB are used only for forming the right-eye image, A projection image tube 33, a projection lens 32, and a red pass filter 31 illustrated in Fig. SA serve to project red light onto the diffusion surface 15 for a left-eye image. below the projection image tube 33, the projection lens 32, and the red-pass filter 31, there are provided similar components for projecting images of green and blue light for the left eye using the Same arrangement as shown in Flq. 8B. The vertically striped images of red, green and blue light in Fig. SB are projected onto the transmissive diffusion gurfaoe lS, and the images of three colors in one set are overlapped as one vertical stripe image which appears as a colored image. The images thus formed appear as a colored three-dimensional image at the viewing points 11 and 12. While the projection image tubes for red, green and blue light are arranged in Fig. 8B in the stated order in the vertical direction, the projection image tubes are not limited to such an order, and may be arranged in any other sequence. Also, the projection image tubes for the left and right eyes need not be arranged in the stated order, and may be in any desired sequence. Schmidt optical systems including projection optios may be employed as the projection image tubes 20, 22, 33 and 36, 39, 42 as shown in Figs. 3 and B. With a Schmidt ystear the optical components 19, 21 and 32, 35, 38, 41 indicated in Fig. 3 and B may be dispensed with, and the shield plate placed directly in front of the phosphor screen surface doubles as an electrode plate for shielding the electron beam. Nhe latter effect is due to the fact that the electron beam strikes the phosphor acreen in the same direction with respect to the plane of the phoaphor screen as that in which light is emitted from the phosphor screen. While two projection image tubes are shown in Figs, 3 and X, as many projection image tubes as desired may be dispoaed in the lateral direction, provided a plurality of such projection image tubes are included. The more projection image tubes, the greater will be the realiaticnese of the displayed three-dimensional images. As the number of projection image tubes is increased, the intervals between slits in the shield plate 16 should of course be correspondingly decreased to reduce the image overlap on the diffusion surfaoe. Fig. 9 is 8 lide elevational view of a projection television apparatus according to the present invention, The projection television apparatus shown in Fig. 9 has a screen 31, cathode-ray tubes 32, 33 and 34 for displaying images in red, green, and blue, respectively, and the optical systems 35, 36 and 37 for projecting the color images displayed on the cathode-ray tubes 32, 33 and 34, re*pecti vely, onto the Screen 31. The light rays representative of the color images projected onto the screen 31 have different incident angles. Fig. 10 is a fragmentary enlarged cross-sectional view of the screen 31 illustrated in Fig. g A substrate 38, which is made of glass or synthetic resin capable of transmitting light, has a surface A where a projected image is observed. The substrate 38 is coated on the entirety of its reverse side with a uniform light-diffusing layer 39 serving to mix colors well and thus enlarge the range in which images can be observed. A light-emitting layer 40 coated on the surface of the light-diffusing layer 39 iS composed of repeating sequences of phosphor stripes 4UX, 4OG and 4OB respectively emitting the three primary colors of light, that is, red, green, and blue. A shield plate 41 is spaced a predetermined distance from the light-emitting layer 40 in a confronting relation thereto. The shield plate 41 has a multiplicity of apertures 42 formed therein for guiding images projected from the cathode-ray tubes 32 to < 4 shown in Fig, 9 as image projectors onto the phosphor stripes 40R, 40G and 403 so that the images will not overlap each other. Also, designated in Fig. 9, at R, G and B, are light rays of projected images in red, green and blue, respectively, which are generated from the cathode-ray tubes 32, 33 and 34 via their respective optical systems. The projection television apparatus of the foregoing embodiment operates as follows. he red image produced by the cathode-ray tube 32 is projected by the optical system 35 onto the screen 31. Since the shield plate 41 is disposed in front of the light-emitting layer 40 of the screen 31, only a portion of the light rays R of the red image passes through the apertures 42 in the shield plate 41 and falls on the phosphor stripes 40R, as indicated by the arrows RX and R2 in Fig. 10. As a result, the phosphor stripes SOR emit red light due to excitation by the light rays R of the red image. Likewise, the light rays G of the green image and the light rays B of the blue image are supplied from the cathode-ray tubes 33 and 342 respectively, and fall on the respective phosphor stripes 40G and 4çBt passing through the apertures 42 in the shield plate 41. The phosphor stripes OG and 40B are thus excited to emit green and blue light. tight rays in the three primaries thus emitted by the phosphor stripes 40R, 4OG and OB are diffused by the light diffusion layer 39 so as to be mixed together and enlarge the range in which the image can be observed. Thereafter, the light rays pass through the transmiseive substrate 38 toward the viewer. Accordingly, projeoted images can be displayed in color at a high brightness level by light rays of the respective image colors which are, in turn, produced by light rays (which may be visible light infrared or ultraviolet radiation, for example) emitted from the cathode-ray tubes 42, 43 and 44 which excite the phosphor stripes 4OR, 40G and 40B. While in the foregoing embodiment the phosphor stripes 40R, 40G and 403 have been described as being arranged in a stripes, the apertures 42 may be farmed in the shield plate 41 in a staggered pattern as shown in fig. 11 and the phosphor stripes 40R, 40G and 40B disposed in positions corresponding to the apertures 42. In such an arrangement, the quality of images displayed is improved since the three colors are well mixed. To increase the contrast of the displayed images, each of the phosphor stripes should be peripherally enclosed by a light-absorbing material such as carbon, or the viewing surface of the substrate 31 should be arranged such that it will absorb extraneous light falling thereon Fig. 12 is a cron ectional view, similar to the view of Pig. 10, illustrating a screen which can be used in the three-dimensional displaying apparatus of Fig. 3. In this case, the image source may emit any of visible light, infrared light or ultraviolet light. Accordingly, stripes 56, 57 and 58 of fluorescent material for emitting red, green and blue light, respectively are disposed on the face of a base of substrate adjacent the shield plate 41. A diffusion layer 54 or the like is disposed under the fluorescent stripes 56, 57 and SS. As in the case of Pig. 3, a lenticular lens is provided. Fig. 13 shows a modification of the screen of Fig. 12 in which the light-emitting portions for eaah of red, green and blue are offset in the longitudinal diretion with respect to one another. The purpose for the relative offsets is to compensate for differences in wavelengths among the red, green and blue light. More particularly, the radius of the curvature of the lenticular lens is constant at any portion thereon, but the wavelength of the image portions in the three different primary colors are different, so that the reflective index of the lenses different for these three colors, thereby producing a dioplaoerent of the three images. Such displacement is compensated for with the arrangement of Fig. 13. Finally, Figs. 14A and 14B are front views of a screen of the type of Figs. 12 or 15, In the case of Fig. 14A, the light-emitting stripes 56, 57 and 58 are arranged in a regular rectangular pattern, while in the arrangement of Fig. 14S, an offset is provided between pairs of two adjacent columns of the stripes. With the projection television apparatus of the present invention as described above, images in the three primary colors are displayed by three respective cathode-ray tubes, and light rays representative of such images are projected from different positions through apertures in a shield plate onto corresponding light-emitting portions of phosphor stripes which constitute a screen, thereby causing the phosphor stripes to display a color image which can be directly observed, Therefore, the displayed image is much brighter than in a conventional device.

Claims: CLAIMS 1, A projected image displaying apparatus including image source means and image displaying means, said image source means optically projecting two-dimensional images onto said image displaying means said image displaying means comprising a transmissive diffusion surface onto which said images produced by said image source means are projected, a vertically striped shield plate disposed on a side of said transmissive diffusion surface adjacent to said image source means for projecting said images onto said transmissive ditfusion surface in the form of overlapping, interleaved stripes, and a lenticular lens plate disposed on an opposite side of said transmissive diffusion surface from said image source means. 2. The projected image displaying apparatus as claimed in claim l, wherein said image source means cooprigea a plurality of image Sources, each projecting a two-dimensional image onto said transmissive diffusion surface in a predetermined wavelength range of visual light. 3. The projected $wage displaying apparatus as claimed in claim 1, wherein said image source means comprises a plurality of image sources for projecting twodimensional monochrome images onto Said transmissive diffusion surface within a wavelength range of visual light, wherein three-dimensional images are composed on said transmissive diffusion surface. 4. The projected image displaying apparatus as claimed in clam 1, wherein said image source means comprises a plurality of pairs of three image sources, each of said three image sources projecting images in respective red, green and blue colors onto said transmissive diffusion surface, three-dimenslonal images being composed on said transmissive diffusion surface. 5. The projected image displaying apparatus as claimed in claim 2, further comprising a Fresnel lens disposed adjacent said shield plate on a elide of said shield plate adjacent said image source means. 6. The projeted image displaying apparatus as claimed in claim 4, further comprising a Fresnel lens disposed adjacent said shield plate on a side of said shield plate adjacent said image source means. 7. The projected image displaying apparatus as claimed in claim 2, wherein said shield plate and said lenticular lens type has a eig-zag interface having a pitch equal to a pitch of stripes On said shield plate 8. The projected image displaying apparatus as claimed in claim 4, wherein said shield plate and said lenticular lens type has a zig-zag interface having a pitch equal to a pitch of stripes on said shield plate. 9. A projected image displaying apparatus including image source means and image displaying earns, Said image source means optically projecting two-dimensional images onto said image displaying means, said image displaying means comprising a substrate capable of tansmitting light tberethrough, a fluorescent layer disposed on said substrate, and a shield plate spaced from said fluorescent layer in confronting relationship thereto having a plurality of striped apertures formed therein. 10. The projected image displaying apparatus of claim 9, wherein said image displaying means further aomprising a lenticular lens plate disposed on an opposite side of said substrate from said image source means. 11, A projected image displaying apparatus including image source means and image displaying seans, said image source mean13 comprising means for projecting first through third energy beams representing images of red, green and blue colors, said image displaying means comprising a substrate capable of transmitting light therethrough, a light-emitting layer disposed on said substrate, and a shield plate spaced from said lightemitting layer in confronting relationship thereto having a plurality Qr striped perturbs formeS heroin for directing said first through third light energy beam from said image source means onto said light-emitting layer in such a manner as to maintain said energy beams interleaved with One another on sated light-emitting layer, said light-emitting layer including a plurality of first phosphor stripes receptive of said first energy beam for emitting light of a first primary color, a plurality of second phosphor stripes receptive of second energy beat for emitting light of a second primary color, and a plurality of third phosphor stirpes receptive of said third energy beam for emitting light of a third primary color, ones of said first through third stripes being arranged parallel to one another in repetitive sequences. 12. The projected image displaying apparatus of claim 11, wherein said first through third phorphor stripes are divided into a plurality ot rectangular patches arranged in rows and columns, and further comprising a lenticular lens disposed on a side of said substrate opposite said image source means. 13. The projected image displaying apparatus of claim 12, wherein said patches of said first through third phosphor stripes are arranged in a regular rectangular matrix of columns and rows. 14 The projected image displaying apparatus of claim 12, wherein said patches of first through third phosphor stripes are arranged in rows and columns with an offset between adjacent pairs of columns in a columnar direction. 15 A projected image displaying apparatus covprisings plurality of projection image tubes, each projecting two-dimensional images, a shield plate having a plurality of vertically oriented apertures formed therein, a diffusion surface for diffusion light, said shield plate being disposed parallel to said diffusion surface on a side thereof adjacent said projection image tubes, lens means for focusing images produced by said projection image tubes onto said diffusion surface through said shield plate, said shield plate being positioned to provide on said diffusion surface images from said projection images tubes in a form of vertically oriented stripes with stripes of images corresponding to each of said projection image tubes being interleaved with one another, and a lenticular lens disposed parallel to said diffusion surface on a side thereof opposite said projection image tubes, 16. A projected image displaying apparatus comprising: a transparent substrate, a light diffusion layer provided on one surface of said substrate, a lightemitting layer formed on said light-diffusion layer, said light-emitting layer comprising a plurality of repeating sequences of phorphor stripes, each of said sequences including stripes for emitting light in red, green and blue colors, and a shield plate disposed parallel to said substrate on a Fiae thereof adjacent said surface, said shield plate having a plurality of vertically oriented apertures formed therein, each of said apertures being positioned over a respective stripe of a single predetermined color.

Inventors: MORISHITA, MASANOBU
Applicants: NEC HOME ELECTRONICS, LTD.
Application year: 1984
Main classification: H04N13
IPC codes: H04N13, H04N9