JP4893250B2 - Projection display - Google Patents

Description

  The present invention relates to a projection display device, and in particular, based on a principle different from holography, a projection type that displays a three-dimensional image as an aerial image using an RGB monochromatic light source such as a light emitting diode or a laser diode as an illumination optical system. The present invention relates to a display device.

  Conventional eyeglassless binocular 3D displays and multi-view 3D displays have image skipping caused by moving the observation position in the horizontal direction, that is, unnaturalness caused by discontinuous motion parallax, and so-called congestion. It has not become widespread due to the problem of eye strain caused by mismatched accommodation.

  In addition, the holography method, which is said to be the ultimate 3D display method, has been put into practical use as a printing technology. The reality is that it is far away.

  However, a concept called super multi-view that solves the above-mentioned problem of inconsistency of congestion and adjustment while using conventional disparity information was found by a research and development project on 3D display performed by the communication and broadcasting mechanism (for example, , Patent Document 1 and Non-Patent Document 1), research on practical application of a natural three-dimensional display using this innovative concept has been activated.

  Even in such research, by reproducing a large number of ray groups obtained by sampling the light emitted by an actual object in units of angles, it is possible to create a three-dimensional model that does not cause horizontal smooth motion parallax and eye strain. The high-density directional display method that realizes color moving image display suggests that a natural and high-quality three-dimensional display can be put to practical use in the near future. The technical content of this high-density directional display method is disclosed in detail in, for example, Patent Document 2.

  Hereinafter, Patent Document 2 will be cited as a conventional example, and an outline of a three-dimensional image display technique based on a high-density directional display method will be described. FIG. 14 is a diagram in which the display principle disclosed in Patent Document 2 is cited. In the figure, each of a plurality of image generation sources has a display angle range 31, and the plurality of image generation sources are arranged in a two-dimensional manner obliquely as shown in FIG. By expanding the angle range as indicated by 34 in FIG. 14B and generating the vertical display angle range 35 common to all images, high-density image display in the horizontal direction is realized. . In FIG. 14, 32 is the horizontal display angle of each image, and 33 is the vertical display angle. In addition, the display itself using such an oblique two-dimensional arrangement is known as a multi-view stereoscopic display before this conventional example (see, for example, Patent Document 3 and Patent Document 4).

  In many multi-view stereoscopic display devices before the conventional example is disclosed, the image generation sources are arranged only in the horizontal direction in order to display images having different display directions in the horizontal direction. Only the viewpoint was displayed. For this reason, there has been a problem that images are switched discontinuously depending on the viewpoint, that is, a problem of discontinuous motion parallax and the problem of eye strain described above.

  However, according to the above conventional example, by arranging the image generation sources not only in the horizontal direction but also in the vertical direction, it becomes possible to arrange a large number of image generation sources at a high density. It became possible to increase more. Moreover, unlike the multi-view stereoscopic display devices described in Patent Document 3 and Patent Document 4 relating to multi-view stereoscopic display using only binocular parallax and convergence, images projected in parallel from many horizontal directions without assuming a viewpoint By collecting light rays in a space using (directivity image) and displaying as a so-called aerial image, it has become possible to perform three-dimensional display independent of the front and rear observation positions.

  As a result, 3D display with smooth motion parallax can be realized, and it is possible to express the material's glossiness and other textures. In addition, when viewing with multiple directional images incident on a single eye, convergence and adjustment It has also been experimentally confirmed that eye strain due to disagreement does not occur.

  Note that Patent Document 5 is disclosed as a conventional example using a large number of projectors for two-dimensional display.

JP 2002-258215 A Japanese Patent No. 3576521 Japanese Patent No. 3533904 Japanese Patent Laid-Open No. 10-505687 JP 2002-214707 A Telecommunications Broadcasting Organization, “Advanced 3D Video Remote Display Project Final Report” (2002)

  However, when a multi-projection type configuration is adopted as an embodiment of a conventional high-density directional display system, there is still a problem regarding image quality. One of the problems is that adjustments must be made so that different colors and luminances are suitable for each projector. In high-density directional display, images from multiple projectors (directional images) are incident on the viewer's retina, so if there is a difference in color or brightness between different projectors, the third order observed at a certain position This is because the original image has uneven color and uneven brightness.

  When a white light source such as a halogen lamp or a xenon lamp is used, uneven color can be eliminated by branching a high output light source such as a xenon lamp with a light guide. This technique is disclosed in Patent Document 5.

  However, for a field sequential display device that uses RGB single-color light sources such as light-emitting diodes (LEDs) and laser diodes in an illumination optical system and drives these light sources in a time-sharing manner, the luminance is sufficient for use as a projector. Since there is no light source, there is a problem that the luminance is insufficient when the light is branched.

  The present invention has been made in view of the above points, and a projection type capable of eliminating uneven color in a three-dimensional image as a configuration capable of emitting uniform illumination light from an illumination light source in a conventional three-dimensional image display device using a spatial image method. An object is to provide a display device.

  Another object of the present invention is to provide a projection display device that can obtain illumination light with sufficient luminance.

In order to achieve the above object, a first aspect of the present invention is a projection display device that displays a three-dimensional image by projecting a plurality of two-dimensional images using a plurality of two-dimensional image display elements. Three or more light sources to be emitted, and a plurality of light branching means for branching the primary color lights respectively emitted from the three or more light sources into the same number of partial primary color lights as the number of two-dimensional image display elements for each primary color light, A plurality of illumination means for individually illuminating a plurality of two-dimensional image display elements with a combination of partial primary color lights of different primary colors separately branched by a plurality of light branching means; and a plurality of two-dimensional image display elements A deflecting optical element array for deflecting the directions of light rays from a plurality of projected two-dimensional images in different directions in units of the two-dimensional images, and forming an intersection of the light rays in a three-dimensional space to display the image Each of the three or more light sources has light adding means by a rod integrator composed of a single light pipe that adds a plurality of the same primary color lights and emits them as uniform illumination light. It is the structure which radiate | emits primary color light, It is characterized by the above-mentioned.

  In this invention, the primary color light emitted from each of the three or more light sources is branched into the same number of partial primary color lights as the number of two-dimensional image display elements for each primary color light, and branched partial primary color lights of different primary colors. Since the plurality of two-dimensional image display elements are individually illuminated with the combined light, the brightness and color of the individual illumination lights respectively illuminating the plurality of two-dimensional image display elements can be made the same.

  In order to achieve the above object, according to a second invention, each of the plurality of illumination means in the first invention is color-combined with partial primary color lights of different primary colors branched separately by the plurality of light branching means. The color composition means for generating white light and the light separation means for separating the white light into the three primary color lights and illuminating the two-dimensional image display element with the three primary color lights thus separated. Features.

  In order to achieve the above object, the third invention provides a two-dimensional image display element for red light that is illuminated with red light, and a green light for each of the plurality of two-dimensional image display elements in the first invention. A two-dimensional image display element for green light illuminated with a blue light and a two-dimensional image display element for blue light illuminated with blue light, and each of a plurality of illumination means is separately divided by a plurality of light branching means. Among the branched partial primary color lights, the two-dimensional image display element is individually illuminated with the corresponding partial primary color light of the primary color.

  In order to achieve the above object, according to a fourth aspect, the three or more light sources in the first aspect are sequentially and cyclically switched one by one for each field of the two-dimensional image display element. Switching means for switching the image to be displayed on the two-dimensional image display element to a primary color light image corresponding to the illumination primary color light in synchronism with each field, and each of the plurality of illumination means is separated by a plurality of light branching means. The two-dimensional image display element is individually illuminated with the partial primary color light branched into two.

In order to achieve the above object, the fifth aspect of the invention reproduces a light space by sampling light rays emitted from an object to be displayed in a three-dimensional image in units of angles, and displays a three-dimensional image as a spatial image. A projection type display apparatus, wherein different primary color lights respectively emitted from three or more light sources are branched into a plurality of partial primary color lights for each primary color light, and the branched partial primary color lights of different primary colors A plurality of illumination optical systems that emit light as illumination light in combination with the illumination optical system array arranged two-dimensionally in the horizontal direction and the vertical direction and illumination light separately emitted from the plurality of illumination optical systems individually A plurality of two-dimensional image display elements to be illuminated are two-dimensionally arranged in a horizontal direction and a vertical direction in a two-dimensional image display element array, and at the center position of each image display of the plurality of two-dimensional image display elements. A plurality of lenses arranged two-dimensionally in the horizontal direction and the vertical direction so that the positions of the respective optical axes are decentered, and divergence from images displayed on each of the plurality of two-dimensional image display elements A projection lens array that individually transmits light and a common image plane on which divergent light from the projection lens array converges are collimated in the horizontal direction and diffused in the vertical direction to be projected into space. have a common screen for forming an aerial image of a three-dimensional, each of the three or more light sources, light from the rod integrator composed of a single light pipe that emits the same primary color light as a plurality addition to uniform illumination light It has an addition means, and is characterized in that the primary color light of uniform illumination light is emitted from the light addition means . In the present invention, it is possible to make the brightness and color of individual illumination lights respectively illuminating a plurality of two-dimensional image display elements the same.

  According to the present invention, it is possible to make the brightness and color of individual illumination lights that respectively illuminate a plurality of two-dimensional image display elements the same, thereby eliminating chromaticity variations between projected images or parallax images. As a result, a compact, high-brightness, high-quality multi-projection type three-dimensional image display device can be realized.

  In addition, according to the present invention, each of the three or more light sources has light adding means for adding a plurality of the same primary color lights, thereby obtaining illumination light with sufficient brightness based on the primary color lights with sufficient power. be able to.

  Next, the best mode for carrying out the present invention will be described with reference to the drawings. FIG. 1 shows a basic configuration diagram of a first embodiment of an illumination optical system of a projection display apparatus according to the present invention. In the figure, the illumination optical system of the projection display apparatus includes a primary color light source of three primary colors composed of a red light source 101R that emits red light, a green light source 101G that emits green light, and a blue light source 101B that emits blue light; Relay lenses 102R, 102G, and 102B provided in a one-to-one correspondence with the primary color light sources 101R, 101G, and 101B, a red light field lens 103R, a green light field lens 103G, and a blue light field lens 103B, and red It has an optical waveguide array for light 104R, an optical waveguide array for green light 104G, and an optical waveguide array for blue light 104B.

  Further, n (n is a natural number of 4 or more) collimator lenses 1051 to 105n, n are provided on the light exit side of the optical waveguide array for red light 104R, the optical waveguide array for green light 104G, and the optical waveguide array for blue light 104B. Each of polarizers 1061 to 106n, n two-dimensional image display elements 1071 to 107n, n RGB color filters 1081 to 108n, n polarization beam splitters 1091 to 109n, and n projection lens units 1101 to 110n. Is provided.

  As the red light source 101R, the green light source 101G, and the blue light source 101B, an LED or a laser diode that emits corresponding predetermined primary color light is used. FIG. 1 shows an embodiment in which light sources of three primary colors R, G, and B are used, and the present invention can be applied as it is even when a multi-primary configuration using more illumination light sources is used. However, for convenience, it is assumed that only the colors R, G, and B are used as primary colors.

  In FIG. 1, the light emitted from the red light source 101R is incident on the optical waveguide array 104R using an optical system in which the loss of optical power is as small as possible. In FIG. 1, the relay lens 102R and the field lens 103R are used to form an image of the red light source 101R on the incident end face of the red light optical waveguide array 104R. For the green light and blue light emitted from the other green light source 101G and blue light source 101B, the images of the respective light sources are formed on the incident end faces of the optical waveguide arrays 104G and 104B in the same manner as the optical system for red light. . Each primary color light from the light sources 101R, 101G, and 101B is incident as uniform illumination on each incident end face of the optical waveguide array 104R, 104G, and 104B.

  These optical waveguide arrays 104R, 104G, and 104B have the same configuration, and for example, a flexible optical fiber bundle (the end face is shown in FIG. 5) or a rigid light guide (not shown) can be used. The light incident on each of the optical waveguide arrays 104R, 104G, and 104B is reflected at the emission end surface by repeating total reflection inside the individual optical waveguides constituting the optical waveguide arrays 104R, 104G, and 104B according to the principle of kaleidoscope illumination. The light intensity distribution is made uniform.

  FIGS. 5A and 5B show the end faces of each example of the optical waveguide array. FIG. 5A shows an optical fiber bundle 104a as the optical waveguide array 104R, 104G, 104B. Unlike the general optical fiber bundle, the optical fiber bundle 104a preferably reduces the loss of uniformly illuminated light as much as possible by bringing the individual optical fibers (optical waveguides) 1041 as close as possible.

In order to do this, the individual optical fibers 1041 are not bonded with an adhesive such as an epoxy resin, but the individual optical fibers 1041 are welded to each other using a glass welding technique, thereby achieving high heat resistance and high throughput. It can be realized in the literature (B. Pailthorpe et.al, “High-resolution display with uniform illumination”, Proc. Asia Display, IDW'01,
pp.1295-1298 (2001)).

  When applied to the aerial image type 3D display of the present invention, the illumination light flux required for each display device is inversely proportional to the number of display devices, and thus the heat resistance requirement is not so high. Therefore, as the optical fiber material, in addition to the above glass, an inexpensive plastic fiber can be used, and the optical fiber material can be used after being bonded with high density.

  As the optical fiber bundle, in addition to the optical fiber bundle 104a having a circular cross section shown in FIG. 5A, a rectangular optical fiber bundle 104b shown in FIG. 5B can be used. However, the optical fiber bundle 104b has a rectangular outer cross-sectional shape, and a large number of optical fibers (optical waveguides) 1042 having a circular cross section are adjacently welded, for example. In particular, when a light pipe having a rectangular cross-section is used as the uniform illumination optical system disposed in the front stage of the optical fiber bundle, matching is performed using the rectangular optical fiber bundle 104b shown in FIG. 5B in order to reduce light loss. It is preferable to take

  Referring back to FIG. 1, light emitted from each of m optical waveguides 104R1 to 104Rm (m is a natural number equal to or larger than n) constituting the optical waveguide array for red light 104R is emitted from the same red light source 101R. Therefore, the hue, the saturation, and the lightness (also referred to as chromaticity in this specification) are the same. Therefore, it is suitable as an illumination optical system for a multi-projection optical system. This is because green light emitted from each of the m optical waveguides 104G1 to 104Gm constituting the green light optical waveguide array 104G and each of the m optical waveguides 104B1 to 104Bm constituting the blue light optical waveguide array 104B. The same applies to the blue light emitted from. The number m of the optical waveguides constituting each primary color optical waveguide array 104R, 104G, 104B is configured to have at least the number n of the two-dimensional image display elements 1071 to 107n to be illuminated.

  The individual optical waveguides constituting the optical waveguide arrays 104R, 104G, and 104B illuminate the two-dimensional image display elements 1071 to 107n by combining three different primary colors. This illumination method differs depending on the types of the two-dimensional image display elements 1071 to 107n. In the present embodiment in which the two-dimensional image display elements 1071 to 107n have RGB color filters 1081 to 108n, the three primary color lights from the individual optical waveguides constituting the optical waveguide arrays 104R, 104G, and 104B are color-synthesized to produce white. Perform by light.

  Although this whitening is not shown in FIG. 1, a known color synthesis optical system using a dichroic filter having wavelength selectivity can be used. Alternatively, when optical fibers are used as the individual optical waveguides 104R1 to 104Rm, 104G1 to 104Gm, and 104B1 to 104Bm, even if a color combining optical system is not used, only R, G, and B3 optical fibers are bundled. Good.

  Here, the individual optical waveguides 104R1 to 104Rm, 104G1 to 104Gm, and 104B1 to 104Bm are optical fibers. For example, red light transmitted through the optical waveguide 104R1, green light transmitted through the optical waveguide 104G1, and transmission through the optical waveguide 104B1. The resulting blue light is color-combined into white light, the white light is converted into parallel light by the collimator lens 1051, and a predetermined polarization plane (for example, a polarization plane in a direction orthogonal to the paper surface of FIG. 1) is formed by the polarizer 1061. The two-dimensional image display element 1071 is illuminated by being converted into linearly polarized light having the same color, reflected by a polarizing beam splitter 1091 and separated into R, G, and B primary colors by an RGB color filter 1081.

  The two-dimensional image display element 1071 has a plurality of pixels regularly arranged in a matrix, each including one red pixel, green pixel, and blue pixel. The reflected light of the three primary colors having chromaticity corresponding to the image from the corresponding pixel is linearly polarized light whose polarization plane is orthogonal to that of the incident light, passes through the RGB color filter 1081, and further passes through the polarization beam splitter 1091 to be a projection lens. The light enters the unit 1101.

  Similarly for the other projection lens units 1102 to 110n, the three primary color lights from the individual optical waveguides are color-combined into white light, which is separated into R, G, and R separated by the RGB color filters 1082 to 108n, respectively. Three primary color lights having chromaticities corresponding to display images from the two-dimensional image display elements 1072 to 107n illuminated with the three primary color lights B are separately transmitted through the polarization beam splitters 1092 to 109n.

  Thus, in the present embodiment, the white light incident on each of the RGB color filters 1081 to 108n provided in front of the two-dimensional image display elements 1071 to 107n is the red light from the same red light source 101R, Since it is white light obtained by color-combining the green light from the same green light source 101G and the blue light from the same blue light source 101B, the chromaticities of each other are the same. The three primary color lights that illuminate the two-dimensional image display elements 1071 to 107n obtained by being separated by the color filters 1081 to 108n also have the same chromaticity between the same primary color lights, thereby causing chromaticity variations between projected images or parallax images. Can be almost eliminated.

  Next, a second embodiment of the present invention will be described. FIG. 2 shows a basic configuration diagram of a second embodiment of the illumination optical system of the projection display apparatus according to the present invention. In the figure, the same components as those in FIG. The second embodiment shown in FIG. 2 is characterized in that a three-plate reflective liquid crystal display element is used as the two-dimensional image display element, as compared with the first embodiment. That is, white light converted into linearly polarized light having a predetermined polarization plane in each of the polarizers 1061 to 106n is separated into three primary color lights of R, G, and B by a color separation optical system, and red light is liquid crystal for red light. Display elements 1111R to 111nR, green light illuminates liquid crystal display elements 1111G to 111nG for green light, and blue light illuminates liquid crystal display elements 1111B to 111nB for blue light.

  Reflected light of the three primary colors according to the display image reflected from the red light liquid crystal display elements 1111R to 111nR, the green light liquid crystal display elements 1111G to 111nG, and the blue light liquid crystal display elements 1111B to 111nB Are linearly polarized light whose polarization planes are orthogonal to each other, and are converted into white light by a known color synthesizing optical system (also referred to as a quad optical system) 1131 to 113n using a prism and separately incident on the projection lens units 1101 to 110n.

  In FIG. 2, light from individual optical waveguides is separated by a color separation optical system, and red light liquid crystal display elements 1111R to 111nR, green light liquid crystal display elements 1111G to 111nG, and blue light liquid crystal display elements 1111B to 1111B. Illustrated to illuminate 111 nB, the red light liquid crystal display elements 1111R to 111nR, the green light liquid crystal display elements 1111G to 111nG, and the blue light liquid crystal display elements 1111B to 111nB correspond to the individual optical waveguides. You may comprise so that it may illuminate directly with primary color light.

  Next, a third embodiment of the present invention will be described. FIG. 3 shows a basic configuration diagram of a third embodiment of the illumination optical system of the projection display apparatus according to the present invention. In the figure, the same components as those in FIG. Compared with the first and second embodiments, the third embodiment shown in FIG. 3 is a field sequential in which n two-dimensional image display elements 1121 to 112n can switch RGB frames of a moving image at high speed. It is characterized in that it is a display element of the system.

  In FIG. 3, each of the red light source 101R, the green light source 101G, and the blue light source 101B uses a single color LED or laser diode that can switch light emission (ON) and light extinction (OFF) at a high speed of 60 Hz or higher. In this embodiment, the red light source 101R, the green light source 101G, and the blue light source 101B are cyclically switched so that only one light source is turned on in synchronization with the fields of the two-dimensional image display elements 1121 to 112n.

  As a result, any one of R, G, and B primary color light is extracted from the collimating lenses 1051 to 105n, and the primary color light is output by the polarizers 1061 to 106n to a predetermined polarization plane (for example, on the paper surface of FIG. 3). Is converted into linearly polarized light having a polarization plane in an orthogonal direction, reflected by the polarization beam splitters 1091 to 109n, and irradiated on the two-dimensional image display elements 1121 to 112n. At this time, the two-dimensional image display elements 1121 to 112n display images of pixels of the same primary color as the primary color light that is illuminated in synchronization with the field in synchronization with the light source switching of the red light source 101R, the green light source 101G, and the blue light source 101B. Switch to display.

  Accordingly, the reflected light from each pixel of the two-dimensional image display elements 1121 to 112n is cyclically switched in synchronization with the field corresponding to the primary color light to be illuminated, and is incident on the projection lens units 1101 to 110n and is publicly known. Displays field sequential display.

  In the above three embodiments, a total of three light sources 101R, 101G, and 101B are used for each of the three primary colors with respect to the single color light source. Next, a fourth type using a plurality of single color light sources is used. The embodiment will be described with reference to FIG.

  FIG. 4 shows a basic configuration diagram of a fourth embodiment of the illumination optical system of the projection display apparatus according to the present invention. In the figure, the same components as those in FIG. The present invention branches primary color light emitted from a light source using optical waveguide arrays 104R, 104G, and 104B such as optical fiber bundles, but it is premised that the original light source has sufficient light output. However, at present, LEDs and laser diodes that can be used in projectors do not yet have sufficient light output to withstand branching.

  Therefore, in order to suitably implement the present invention, it is desirable to use a plurality of monochromatic light sources (such as LEDs) of the same color and add and increase the light output. Various methods can be considered as such a light addition method. As shown in FIG. 4, a plurality of single-color light sources of the same color are mounted on the rod integrators 114R, 114G, and 114B made of light pipes to make the light addition compact. A high output light source can be provided.

  That is, as shown in FIG. 4, for example, by attaching three red light sources 101R1, 101R2, and 101R3 to a rod integrator 114R made of one light pipe, the light output is three times that of one red light source 101R. Can be obtained. Light emitted from the rod integrator 114R enters the optical waveguide array 104R. At this time, the red light incident on the incident end face of the optical waveguide array 104R shown in FIG. 5A or FIG. 5B does not differ in luminance between the center and the periphery of the optical fiber bundle, The luminances of the three red light sources 101R1, 101R2, and 101R3 are set so as to be incident as uniform illumination with uniform luminance over the entire incident end face.

  Similarly, for the green light source, three green light sources 101G1, 101G2, and 101G3 are attached to a rod integrator 114G that is made up of one light pipe, and for the blue light source, three blue light sources 101B1, 101B2, and 101B3 are combined into one. By attaching to the rod integrator 114B made of a light pipe, it is possible to obtain a light output that is three times that of a single monochromatic light source, and these light outputs are incident on the incident end faces of the optical waveguide arrays 104G and 104B as uniform illumination light. To do.

  The light emitted from these light sources is branched by the optical waveguide arrays 104R, 104G, and 104B by approximately the same number as the number of the projection lens units 1101 to 110n, and the above-described first to third are divided according to the type of the two-dimensional image display element. What is necessary is just to illuminate similarly to having demonstrated in embodiment of this. In FIG. 4, the two-dimensional image display element is shown by way of example of the field sequential display two-dimensional image display elements 1121 to 112n according to the third embodiment. The first embodiment of the first embodiment or the second embodiment of FIG. 2 may be used.

  Next, an embodiment in which the present invention is applied to a multi-projection type three-dimensional display will be described in detail with reference to FIGS. The three-dimensional display according to the present embodiment relates to a so-called aerial image reproduction type three-dimensional display that reproduces an image by reproducing a large number of light rays in space. That is, instead of the multi-view stereoscopic display in which the projection light is collected at the position of the observer's eyes and the entire two-dimensional image (perspective projection image) displayed by one projector is incident on the observer's pupil, one projector is used. A part of the image (parallel projection image) is made incident on the pupil of the observer, and a retinal image is formed as an integral of partial images from different projectors. This is because the aerial image method requires less light power to be applied to one projector than the multi-view method, and thus the present invention can be more suitably implemented. Of course, this does not mean that the present invention is not applicable to multi-view stereoscopic displays.

  FIG. 6 is a diagram showing a basic configuration of an embodiment of the projection type display apparatus of the present invention. 6A is a perspective view of the entire apparatus, and FIG. 6B is a front view of an array optical system constituting the apparatus. In FIG. 6, the three-dimensional image display device includes a two-dimensional image display device array 10, a lens array 12, an aperture array 14, a shared lens 16, and a vertical diffusion plate 17. Reference numeral 18 denotes a common image plane, and 19 denotes an optical axis.

  FIG. 6B is a front view of the above-described array optical system. The two-dimensional image display device array 10 has a configuration in which a plurality of two-dimensional image display devices 11 are two-dimensionally arranged obliquely. . The lens array 12 includes a plurality of lenses 13 provided at positions corresponding to the two-dimensional image display device 11. The aperture array 14 includes a plurality of apertures 15 provided at positions corresponding to the plurality of lenses 13. In the present embodiment, the shared lens 16, the vertical diffusion plate 17, and the common image plane 18 are arranged almost integrally.

  FIGS. 7A and 7B are top views showing the light beam state of the main part of the projection display device of the present invention, and FIGS. 8A and 8B are side views thereof. FIGS. 7A and 8A show the light beam state when the two-dimensional image display device 11 is on the optical axis 19 of the entire array optical system. FIGS. 7B and 8B show the light beam state when the two-dimensional image display device 11 is located at a position off the optical axis 19.

  7 and 8, the hatched area represents an area where light rays from the image displayed on the two-dimensional image display device 11 exist. In addition, light rays indicated by solid lines near the boundary of this region show three typical light rays that pass through the individual openings 15. That is, one principal ray that passes through the center of the opening 15 and two marginal rays that pass through the edge of the opening 15.

  As indicated by the optical paths of these principal rays (principal rays) and outer marginal rays (marginal rays), the divergent rays emitted from the two-dimensional image display device 11 converge on the common image plane 18 near the shared lens 16. That is, the two-dimensional image display device 11 and the shared lens 16 are substantially in an imaging relationship. This means that the shared lens 16 does not contribute to image formation. However, the contribution of the shared lens 16 is present in the three-dimensional image formed by the group of rays diverging again after being imaged by the shared lens 16 as will be described in detail later.

  In the present embodiment, the vertical diffusion plate 17 that does not diffuse light in the horizontal direction is disposed close to the shared lens 16 so that light is diffused only in the vertical direction. As an embodiment of the screen composed of the shared lens 16 and the vertical diffusing plate 17, there are two kinds of forms, that is, a case where it is constituted by one piece and a case where it is constituted by two pieces as shown in FIGS. Conceivable. FIG. 9A shows an example in which the shared lens 16 and the vertical diffusing plate 17 are integrated as a screen. FIG. 5A shows a case where a Fresnel lens is used as the shared lens 16 and a lenticular sheet is used as the vertical diffusion plate 17. After the common image surface 18 is made telecentric by matching the Fresnel lens surface 16 on the back surface, the difference in display direction is eliminated by the vertical diffusion plate 17 on the viewer side.

  As the vertical diffusion plate 17, a holographic screen can be used in addition to the lenticular sheet. Further, by forming a catadioptric optical system (catadioptric optical system) that is bent using a plane mirror or a concave mirror between the shared lens 16 and the lens array 12, the depth of the apparatus can be reduced.

  FIG. 9B shows an example in which the shared lens 16 and the vertical diffusing plate 17 are composed of two sheets. By using a double lenticular sheet formed on both sides as shown in the figure as the vertical diffusion plate 17, more excellent diffusibility can be provided in the vertical direction. Examples of such a screen that have been put into practical use include a Fresnel wrench screen for a rear projection television.

  In the present embodiment, the central axis of the two-dimensional image display device 11 does not coincide with the optical axis of each lens 13 and the optical axis of each opening 15, and is decentered in parallel. That is, as shown in FIG. 7 or FIG. 8, the optical axis of each lens 13 (shown by a dashed line) and the light of each opening 15 with respect to the central axis (not shown) of the two-dimensional image display device 11. The axis (shown with a dashed line) is shifted. The light passing through the diaphragm centers of these individual optical systems passes through the center of the shared lens 16. Therefore, the display direction of the image necessary for the three-dimensional display is not given by the shared lens 16, but is given from the beginning by the individual optical systems having decentering. This decentered optical system will be described in more detail with reference to FIG.

  FIG. 10 is a diagram showing an embodiment of a projection optical system array having decentration. In the figure, the same components as those in FIG. In FIG. 10, two orthogonal straight lines are a horizontal axis 2 representing the horizontal direction and a vertical axis 3 representing the direction perpendicular thereto. The horizontal direction is a direction parallel to the direction connecting the two eyes of the viewer of the display image. As shown in FIG. 10, in the present embodiment, the two-dimensional image display device 11 that is an image generation source is shifted obliquely so that the positions projected on the horizontal axis 2 do not coincide with each other in the vertical axis 3 direction. It is arranged. And with respect to these two-dimensional image display apparatuses 11, each lens 13 and opening 15 are shifted in the horizontal direction and the vertical direction by different eccentric amounts.

  Previously, the lens shift of the projection lens was accompanied by image distortion and image degradation. However, due to recent advances in optical design technology, even if the lens shift is performed in the horizontal and vertical directions, the image quality will deteriorate. A projector having a projection lens that is less than an allowable value and does not require electrical distortion correction has been developed, and the present applicant also manufactures and sells the projector.

  7 and 8, the shared lens 16 and the vertical diffusion plate 17, which are screens arranged in the vicinity of the common image plane 18, are enlarged image sizes of the two-dimensional image display device 11 formed on the common image plane 18. Project into the space without changing. That is, two light beams emitted from each of the plurality of two-dimensional image display devices 11 are refracted by the shared lens 16 so that two light beams are parallel each other. That is, the shared lens 16 is configured to be telecentric without changing the propagation direction of the pupil given by the lens shift described above.

  A three-dimensional image is formed by the light beam that is telecentric in the horizontal direction and diffused in the vertical direction by the screen including the shared lens 16 and the vertical diffusion plate 17.

  Next, the visual observation of the above three-dimensional image will be described. FIG. 11 is a diagram illustrating an example of an image on the membrane of an observer at the time of naked eye observation. FIG. 11A is an image on the retina that is observed when an observer sees a spatial image of the sphere 21 and the cube 22 at a certain observation position. The retinal image shown in FIG. 11A has a high directivity and telecentric light rays are projected onto the space, so that only a part of the parallel projection image displayed on the two-dimensional image display device 11 is incident on the eyes. Therefore, a partial image is observed. In the vertical direction, the exit pupil is enlarged by the vertical diffusing plate 17, so that a vertically long strip-shaped image is obtained. The retinal image is an image in which these strip-like images from different projectors are arranged on the retina, and a plurality of strip-like images are connected as shown in FIG.

  Examples of such strip-shaped images are shown in FIGS. These show images that are observed with the naked eye when an image is displayed only on one two-dimensional image display device 11 in the two-dimensional image display device array 10 in FIG. 6. In FIG. 12A, an image of the left part of the spherical space image 21 is displayed. At this time, when the observation position is moved in the horizontal direction, the image of the central portion of the spherical space image 21 can be visually observed as shown in FIG. When the observation position is further moved in the horizontal direction, the right end of the spherical aerial image 21 shown in FIG. 12C, the left end of the cubic aerial image 22 shown in FIG. 12D, and FIG. The projected image at the right end of the cubic aerial image 22 shown in FIG. 12F can be sequentially observed with the naked eye in the vicinity of the center of the cubic aerial image 22.

  Further, even when the observation position is fixed and the two-dimensional image display devices 11 of the two-dimensional image display device array 10 are sequentially turned on one by one. Images similar to those shown in FIGS. 12A to 12F can be observed with the naked eye. Needless to say, images projected from different directions are displayed on the different two-dimensional image display devices 11, so that the strip images observed with the naked eye are strictly parallax with FIGS. 12 (a) to 12 (f). Only the amount is different.

  Here, if there is even a slight color unevenness or luminance unevenness in these individual strip-shaped images, when all the two-dimensional image display devices 11 are turned on, the images are smoothly as shown in FIG. The retinal image cannot be connected. In the present invention, as described with reference to FIGS. 1 to 5, in order to suppress such color unevenness, a common monochromatic light source is used to divide the emitted light by an optical fiber bundle or the like, and the color is synthesized after being branched. In this way, the uneven color was completely eliminated.

  Next, a specific example for carrying out the present invention will be described in detail with reference to FIG. FIG. 13 is a structural view from the upper surface direction of the main part of an embodiment of the projection display device according to the present invention. In the figure, the same components as those in FIGS. 1 to 4 and 6 are denoted by the same reference numerals.

  In FIG. 13, the two-dimensional image display element 1121, the polarization beam splitter 1091, and the projection lens unit 1101 constitute the projector 100. Similarly, the two-dimensional image display elements 1122 to 112n, the polarizing beam splitters 1092 to 109n, and the projection lens units 1102 to 110n also form second to nth projectors, respectively.

  Each projector such as the projector 100 is a two-dimensional image projection device having a decentered photographing optical system, and is arranged two-dimensionally in the horizontal direction and the vertical direction as a whole to constitute a two-dimensional image projection device array. . The projection lens unit 1101 includes an incident-side projection lens 211, an aperture stop 212 inside the projection lens, and an exit-side projection lens 213. The same applies to the other projection lens units 1102 to 110n. The two-dimensional image display elements 1121 to 112n correspond to the two-dimensional image display device 11 shown in FIG. 6B, and the two-dimensional image display device array 10 shown in FIGS. It is composed. Each of the projection lens units 1101 to 110n corresponds to the lens 13 and the aperture 15 in FIG. 6B, and constitutes the lens array 12 and the aperture array 14 shown in FIGS. 6A and 6B as a whole. ing.

  Projected images of the subject are displayed on the two-dimensional image display elements 1121 to 112n in FIG. 13 by a reproduction device and a drive circuit (not shown). As a method of introducing light from the illumination light source into the two-dimensional image display elements 1121 to 112n in FIG. 13, a projector optical system using a general reflective liquid crystal display element can be used. In FIG. 13, the field sequential display two-dimensional image display elements 1121 to 112n shown in FIG. 3 or FIG. 4 are shown as an example of the two-dimensional image display element, but the two-dimensional image shown in FIG. Although a display element may be sufficient and the illumination light source is not illustrated in FIG. 13, any one of the illumination optical systems illustrated in FIGS. 1 to 4 can be used.

  As the two-dimensional image display elements 1121 to 112n, it is preferable to use LCOS (Liquid Crystal On Silicon) which is a reflective liquid crystal display element having a high resolution. In particular, among D-ILA (registered trademark), which is an LCOS manufactured and sold by the present applicant, when a resolution of 4096 × 2160 pixels is used, a large-screen, high-resolution three-dimensional image display device is suitably realized. can do.

  Of course, instead of the two-dimensional image display elements 1121 to 112n, transmissive liquid crystal typified by HTPS (High Temperature Poly-Silicon: High-Temperature Polysilicon TFT Liquid Crystal) or other micro-type such as DLP (Digital Light Processing: registered trademark). It is also possible to use a display device (Micro Display Device: MD). In that case, the light source, the illumination optical system, and the polarization beam splitters 1091 to 109n may be replaced with ones suitable for each microdisplay device.

  The two-dimensional image light beams emitted from the two-dimensional image display elements 1121 to 112n are transmitted through the polarization beam splitters 1091 to 109n in a telecentric state, and then enter the projection lens units 1101 to 110n separately. The projection lens units 1101 to 110n form an enlarged image of the two-dimensional image display elements 1121 to 112n in the vicinity of the shared lens (Fresnel lens) 16 and then n vertically long strips on the retina 23 of the observer. A three-dimensional aerial image connected with the image is formed.

  As described above in detail, according to the present embodiment, the illumination optical system can substantially eliminate chromaticity variations between projected images or parallax images. Therefore, in the conventional three-dimensional image display device using the aerial image method, The unevenness of color and brightness of the displayed three-dimensional image can be eliminated, and the common lens 16, the vertical diffusing plate 17 and the common image plane 18 are arranged in close proximity to each other, thereby projecting a two-dimensional image. Since the optical path length from the device to the common image plane and the size of the shared lens are reduced, a simple and small projector array can be configured.

  The present invention is not limited to the above-described embodiment. For example, the light source is not limited to the three monochromatic light sources for R, G, and B, and may be three or more monochromatic light sources.

It is a fundamental lineblock diagram of a 1st embodiment of an illumination optical system of a projection type display of the present invention. It is a basic block diagram of 2nd Embodiment of the illumination optical system of the projection type display apparatus of this invention. It is a basic block diagram of 3rd Embodiment of the illumination optical system of the projection type display apparatus of this invention. It is a basic block diagram of 4th Embodiment of the illumination optical system of the projection type display apparatus of this invention. It is a figure which shows the end surface of each example of an optical waveguide array. It is a figure which shows the basic composition of one Embodiment of the projection type image display apparatus of this invention. It is a top view which shows the light ray state of the principal part of the projection type display apparatus of this invention. It is a side view which shows the light ray state of the principal part of the projection type display apparatus of this invention. It is a perspective view which shows each example of the screen which consists of a shared lens in FIG. 6, and a vertical direction diffuser. It is a figure which shows one Embodiment of the projection optical system array with a decentration in this invention. It is a figure which shows an example of the image on the membrane of an observer at the time of macroscopic observation. It is a figure which shows the example of a strip image observed with the naked eye. It is a block diagram from the upper surface direction of the principal part of one Embodiment of the projection type display apparatus of this invention. It is a display principle explanatory drawing of an example of the conventional three-dimensional display.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Two-dimensional image display apparatus array 11 Two-dimensional image display apparatus 12 Lens array 13 Lens 14 Aperture array 15 Aperture 16 Shared lens 17 Vertical direction diffuser 18 Common image surface 19 Optical axis 100 Projector (two-dimensional image projection apparatus)
101R Red light source 101G Green light source 101B Blue light source 102R, 102B, 102B Relay lens 103R, 103G, 103B Field lens 104R, 104G, 104B Optical waveguide array 1051-105n Collimating lens 1061-106n Polarizer 1071-107n, 1121-112n Two-dimensional Image display element 1081 to 108n RGB color filter 1091 to 109n Polarizing beam splitter 1101 to 110n Projection lens unit 1111R to 111nR Liquid crystal display element for red light 1111G to 111nG Liquid crystal display element for green light 1111B to 111nB Liquid crystal display element for blue light 1131 113n Color synthesis optical system 114R, 114G, 114B Rod integrator comprising light pipe

Claims (5)

In a projection type display device that displays a three-dimensional image by projecting a plurality of two-dimensional images using a plurality of two-dimensional image display elements,
Three or more light sources that emit different primary colors;
A plurality of light branching means for branching the primary color light respectively emitted from the three or more light sources into the same number of partial primary color lights as the number of the two-dimensional image display elements for each primary color light;
A plurality of illumination means for individually illuminating the plurality of two-dimensional image display elements with light obtained by combining the partial primary color lights of different primary colors separately branched by the plurality of light branching means;
A deflection optical element array that deflects the directions of light rays from a plurality of two-dimensional images projected from the plurality of two-dimensional image display elements in directions different from each other in units of the two-dimensional image;
Displaying a three-dimensional aerial image by forming the intersection of the rays in space ;
Each of the three or more light sources has a light adding means by a rod integrator composed of a single light pipe that adds a plurality of the same primary color lights and emits them as uniform illumination light. A projection type display device characterized in that the primary color light of illumination light is emitted . Each of the plurality of illumination means includes
Color synthesizing means for generating white light by color synthesizing the partial primary color lights of different primary colors separately branched by the plurality of light branching means;
The projection display apparatus according to claim 1, further comprising: a light separation unit that separates the white light into three primary color lights and illuminates the two-dimensional image display element with the separated three primary color lights. Each of the plurality of two-dimensional image display elements is illuminated with red light, a two-dimensional image display element for red light that is illuminated with red light, a two-dimensional image display element for green light that is illuminated with green light, and a blue light. It consists of a two-dimensional image display element for blue light,
Each of the plurality of illumination means is means for individually illuminating the two-dimensional image display element with a partial primary color light of a corresponding primary color among the partial primary color lights branched separately by the plurality of light branching means. The projection type display device according to claim 1. The three or more light sources are sequentially switched one by one in units of fields of the two-dimensional image display element, and the light source that performs the light emission operation is a primary color corresponding to the illumination primary color light. Switching means for switching to the light image in synchronism with the field unit;
2. The plurality of illumination means are means for individually illuminating the two-dimensional image display element with the partial primary color light separately branched by the plurality of light branching means. Projection display device. A projection display device that reproduces a light space by sampling light rays emitted by an object to be displayed in a three-dimensional image in units of angles, and displays a three-dimensional image as a spatial image,
Different primary color lights respectively emitted from three or more light sources are branched into a plurality of partial primary color lights for each primary color light, and the split primary color lights of different primary colors are combined to emit light as illumination light. An illumination optical system array in which a plurality of illumination optical systems are two-dimensionally arranged in a horizontal direction and a vertical direction;
A plurality of two-dimensional image display elements individually illuminated with illumination light emitted separately from the plurality of illumination optical systems, a two-dimensional image display element array arranged two-dimensionally in the horizontal direction and the vertical direction;
A plurality of lenses arranged two-dimensionally in the horizontal direction and the vertical direction so that the position of each optical axis is decentered with respect to the center position of each image display of the plurality of two-dimensional image display elements, A projection lens array that individually transmits divergent light from images displayed on each of the plurality of two-dimensional image display elements;
Commonly arranged near the common image plane where the divergent light from the projection lens array converges, parallelizes the divergent light in the horizontal direction, diffuses it in the vertical direction, and projects it into space to form a three-dimensional aerial image. possess a screen,
Each of the three or more light sources has a light adding means by a rod integrator composed of a single light pipe that adds a plurality of the same primary color lights and emits them as uniform illumination light. A projection type display device characterized in that the primary color light of illumination light is emitted .