JP2010237691A - Three-dimensional image display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a three-dimensional image display which certainly avoid a difficulty of viewing three-dimensional images due to overlapping of a light source or an optical system with the three-dimensional images. <P>SOLUTION: The three-dimensional image display includes: (A) light modulation means 30 which is configured to generate a two-dimensional image and emits a spacial frequency in the generated two-dimensional image along diffraction angles; (B) image restriction and generation means 32 which is configured to generate Fourier transformed images corresponding to a plurality of diffraction orders in number, select only predetermined Fourier transformed images, perform inverse Fourier transformation of the selected Fourier transformed image, and generate conjugate image of the two-dimensional image generated by the light modulation means; (C) an over-sampling filter OSF; (D) a Fourier transform image forming means 40; (E) a Fourier transform image selecting means 50; (F) a conjugate image forming means 60; and a semitransparent mirror 90 which is configured to change a travelling direction of a light ray emitted from the optical system. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a three-dimensional image display device capable of displaying a stereoscopic image.

  Both eyes of the observer can obtain a plurality of stereoscopic images from different viewpoints by preparing a plurality of sets of parallax images or a binocular stereoscopic image technique for obtaining stereoscopic images by observing different images called parallax images. Ocular stereoscopic image technology is known, and many technologies related to these have been developed. However, in the binocular stereoscopic image technology and the multi-view stereoscopic image technology, the stereoscopic image is not located in a space intended as a stereoscopic image, but exists on a two-dimensional display surface, for example. Located at a certain position. Accordingly, convergence and adjustment, which are visual system physiological reactions in particular, do not work together, and eye strain associated therewith is a problem.

  On the other hand, in the real world, information on the surface of an object propagates to an observer's eyeball using light waves as a medium. A holography technique is known as a technique for artificially reproducing a light wave from an object surface that physically exists in the real world. A stereoscopic image using the holography technique uses an interference fringe generated based on light interference, and uses a diffraction wavefront itself generated when the interference fringe is illuminated with light as an image information medium. Therefore, visual system physiological reactions such as convergence and adjustment similar to those when the observer observes an object in the real world occur, and an image with less eye strain can be obtained. Furthermore, the fact that the light wavefront from the object is reproduced means that continuity is ensured in the direction in which image information is transmitted. Therefore, even if the observer's viewpoint moves, it is possible to continuously present appropriate images from different angles according to the movement, and motion parallax can be continuously provided.

  However, in the holography technology, three-dimensional space information of an object is recorded as interference fringes in a two-dimensional space, and the amount of information is extremely large compared to the amount of information in a two-dimensional space such as a photograph of the same object taken. Amount. This is because it can be considered that when the three-dimensional space information is converted into the two-dimensional space information, the information is converted into the density in the two-dimensional space. Therefore, the spatial resolution required for a display device that displays interference fringes by CGH (Computer Generated Hologram) is extremely high, and an enormous amount of information is required. Realizing a stereoscopic image based on a real-time hologram At present, it is technically difficult.

  In the holography technique, light waves that can be regarded as continuous information are used as an information medium to transmit information from an object. On the other hand, as a technique for generating a stereoscopic image by discretizing light waves and recreating a situation that is theoretically equivalent to a field consisting of light waves in the real world with light rays, the light ray reproduction method (also called the integral photography method) )It has been known. In the light beam reproduction method, a light beam group composed of a large number of light beams propagating in many directions is scattered in the space in advance by optical means. Next, a light ray propagating from the surface of a virtual object located at an arbitrary position is selected from the group of light rays, and the intensity or phase of the selected light ray is modulated, so that an image composed of the light rays is converted into a space. Generate. An observer can observe this image as a stereoscopic image. A stereoscopic image obtained by the ray reconstruction method is an image in which images from a plurality of directions are multiplexed at an arbitrary point, and the viewing position of an arbitrary point is the same as when a three-dimensional object is viewed in the real world. The way it looks is different.

  As an apparatus for realizing the above-described light beam reproduction method, an apparatus combining a flat display device such as a liquid crystal display device or a plasma display device with a microlens array or a pinhole array has been proposed (for example, the following). (See Patent Literature 1 to Patent Literature 7). An apparatus in which a large number of projector units are arranged is also conceivable. FIG. 52 shows an example of the configuration of a three-dimensional image display apparatus that realizes a light beam reproduction method using a projector unit. In this apparatus, a large number of projector units 301 are arranged in parallel in the horizontal direction and the vertical direction, and light beams having different angles are emitted from each projector unit 301. As a result, a multi-view angle image is multiplexed and reproduced at an arbitrary point in a certain cross section 302 to realize a stereoscopic image.

Japanese Patent Application Laid-Open No. 2007-041504 includes
(A) It has a plurality of pixels, the light from the light source is modulated by each pixel to generate a two-dimensional image, and the spatial frequency in the generated two-dimensional image corresponds to the plurality of diffraction orders generated from each pixel Light modulating means for emitting along the diffraction angle,
(B) Fourier transform image forming means for generating a Fourier transform image of a number corresponding to the plurality of diffraction orders by Fourier transforming the spatial frequency in the two-dimensional image emitted from the light modulation means;
(C) Fourier transform image selection means for selecting a Fourier transform image corresponding to a desired diffraction order among Fourier transform images generated in a number corresponding to the plurality of diffraction orders, and
(D) conjugate image forming means for forming a conjugate image of the Fourier transform image selected by the Fourier transform image selection means;
Is disclosed.

JP 2003-173128 A Japanese Patent Laid-Open No. 2003-161912 JP 2003-295114 A JP 2003-75771 A JP 2002-72135 A JP 2001-56450 A Japanese Patent No. 3523605 JP 2007-041404 A

  According to the above-described light ray reproduction method, an image is obtained with light rays that are effective for focus adjustment as a visual function and binocular convergence angle adjustment, which is impossible with binocular stereoscopic image technology and multi-view stereoscopic images. Therefore, it is possible to provide a stereoscopic image with very little eye strain. In addition, since light rays are continuously emitted in a plurality of directions from the same element on the virtual object, it is possible to continuously provide a change in the image accompanying the movement of the viewpoint position.

  However, an image generated by the current light beam reproduction method lacks a sense of reality compared to an object in the real world. This is because the stereoscopic image by the current light beam reproduction method is generated by a very small amount of information, that is, a small amount of light with respect to the amount of information obtained by the observer from the object in the real world. Conceivable. In general, it is said that the human visual perception limit is about 1 minute in angular resolution, and a three-dimensional image by the current light beam reproduction method is generated by light rays that are insufficient for human vision. Therefore, in order to generate a stereoscopic image having high realism and reality of an object in the real world, it is a problem to generate an image with at least a large amount of light.

  In order to realize this, a technique capable of generating a light beam group with high spatial density is required, and it is conceivable to increase the display density of a display device such as a liquid crystal display device. Alternatively, in the case of an apparatus having a large number of projector units 301 shown in FIG. 52, it is conceivable that the projector units 301 are miniaturized as much as possible and are arranged with high spatial density. However, a dramatic improvement in display density in current display devices is difficult due to problems of light utilization efficiency and diffraction limit. In the case of the apparatus shown in FIG. 52, it is considered difficult to arrange the projector units 301 at a high spatial density because there is a limit to downsizing the projector units 301. In any case, in order to generate a high-density light beam group, a plurality of devices are required, and the overall size of the apparatus cannot be avoided.

  In the three-dimensional image display device disclosed in Japanese Patent Application Laid-Open No. 2007-041504, a group of light beams necessary for displaying a three-dimensional image can be generated at a high spatial density without increasing the size of the entire three-dimensional image display device. It is possible to scatter and obtain a stereoscopic image with light rays that are close to the same quality as real-world objects. However, in the three-dimensional image display device disclosed in Japanese Patent Application Laid-Open No. 2007-041504, when observing the Fourier transform image (stereoscopic image) selected by the Fourier transform image selection means, the light source and the optical elements constituting the three-dimensional image display device are used. There is a problem that the system is located in the field of view of the observer, the light source and the optical system overlap with the stereoscopic image, and the stereoscopic image becomes difficult to see.

  In addition, from the viewpoint of reducing the burden of the image data processing system in the three-dimensional image display device, even if a group of rays necessary for displaying a stereoscopic image is generated and scattered spatially at a lower density, There is also a strong demand for a technology that can obtain a three-dimensional image close to the same quality.

  Accordingly, a first object of the present invention is to provide a three-dimensional image display device that can surely avoid the occurrence of a problem that a light source and an optical system overlap with a stereoscopic image and the stereoscopic image becomes difficult to see. A second object of the present invention is to provide a three-dimensional image display device having a configuration and structure that can reduce the burden on an image data processing system.

The three-dimensional image display apparatus according to the first aspect of the present invention for achieving the first object includes a light source and an optical system.
The optical system is
(A) It has a plurality of pixels, the light from the light source is modulated by each pixel to generate a two-dimensional image, and the spatial frequency in the generated two-dimensional image corresponds to the plurality of diffraction orders generated from each pixel Light modulating means for emitting along the diffraction angle,
(B) Fourier transform image forming means for generating a Fourier transform image of a number corresponding to the plurality of diffraction orders by Fourier transforming the spatial frequency in the two-dimensional image emitted from the light modulation means;
(C) Fourier transform image selection means for selecting a Fourier transform image corresponding to a desired diffraction order among Fourier transform images generated in a number corresponding to the plurality of diffraction orders, and
(D) conjugate image forming means for forming a conjugate image of the Fourier transform image selected by the Fourier transform image selection means;
Consists of.

The three-dimensional image display device according to the 2A aspect of the present invention for achieving the first object includes a light source and an optical system,
The optical system is
(A) P × Q apertures (where P and Q are arbitrary positive integers) arranged in a two-dimensional matrix along the X and Y directions, and the passage and reflection of light from the light source Alternatively, a two-dimensional image is generated by controlling diffraction for each aperture, and based on the two-dimensional image, M sets (m-th to m′-th) from the m-th order along the X direction for each aperture. Where m and m ′ are integers, M is a positive integer), and N sets from the nth order to the n′th order along the Y direction (where n and n ′ are integers, N is A two-dimensional image forming apparatus that generates a total of M × N sets of diffracted light.
(B) a first lens in which a two-dimensional image forming apparatus is disposed on the front focal plane;
(C) A spatial filter that is arranged on the rear focal plane of the first lens and has a total of M × N opening / closing controllable openings, M in the X direction and N in the Y direction. ,
(D) a second lens having a spatial filter disposed on its front focal plane, and
(E) a third lens whose front focal point is located at the rear focal point of the second lens;
Consists of.

The three-dimensional image display device according to the 3A aspect of the present invention for achieving the first object includes a light source and an optical system,
The optical system is
(A) A one-dimensional spatial light modulator that has P pixels along the X direction and generates a one-dimensional image; two-dimensionally expands the one-dimensional image generated by the one-dimensional spatial light modulator; A scanning optical system for generating a two-dimensional image; and M sets from the m-th order to the m′-th order (where m and m ′ are integers) arranged on the generation surface of the two-dimensional image; , M is a positive integer) a two-dimensional image forming apparatus comprising diffracted light generating means for generating diffracted light,
(B) a first lens in which diffracted light generating means is disposed on the front focal plane;
(C) Arranged on the rear focal plane of the first lens, M × N in the X direction and N in the Y direction (where N is a positive integer). A spatial filter having a controllable opening,
(D) a second lens having a spatial filter disposed on its front focal plane, and
(E) a third lens whose front focal point is located at the rear focal point of the second lens;
Consists of.

The three-dimensional image display apparatus according to the 4A aspect of the present invention for achieving the first object includes a light source and an optical system.
The optical system is
(A) It has a plurality of pixels, the light from the light source is modulated by each pixel to generate a two-dimensional image, and the spatial frequency in the generated two-dimensional image corresponds to the plurality of diffraction orders generated from each pixel Light modulating means for emitting along the diffraction angle,
(B) Fourier transform the spatial frequency in the two-dimensional image emitted from the light modulation means to generate a number of Fourier transform images corresponding to a plurality of diffraction orders generated from the pixels, An image limiting / generating unit that selects only a predetermined Fourier transform image, and further performs inverse Fourier transform on the selected Fourier transform image to form a conjugate image of the two-dimensional image generated by the light modulation unit,
(C) an oversampling filter having a plurality of aperture regions and emitting spatial frequencies in a conjugate image of a two-dimensional image along diffraction angles corresponding to a plurality of diffraction orders generated from the respective aperture regions;
(D) Fourier transform image formation in which the spatial frequency in the conjugate image of the two-dimensional image emitted from the oversampling filter is Fourier transformed to generate a number of Fourier transform images corresponding to a plurality of diffraction orders generated from the aperture regions. means,
(E) Fourier transform image selection means for selecting a Fourier transform image corresponding to a desired diffraction order among Fourier transform images generated in a number corresponding to a plurality of diffraction orders generated from each aperture region; and
(F) conjugate image forming means for forming a conjugate image of the Fourier transform image selected by the Fourier transform image selection means;
Consists of.

The three-dimensional image display apparatus according to the 5A aspect of the present invention for achieving the first object includes a light source and an optical system.
The optical system is
(A) It has openings arranged in a two-dimensional matrix along the X and Y directions, and generates a two-dimensional image by controlling the passage, reflection, or diffraction of light from the light source for each opening, A two-dimensional image forming apparatus that generates diffracted light of a plurality of diffraction orders for each aperture based on the two-dimensional image;
(B) a first lens in which a two-dimensional image forming apparatus is disposed on the front focal plane;
(C) a scattering diffraction limiting aperture that is disposed on the rear focal plane of the first lens and allows only diffracted light of a predetermined diffraction order to pass;
(D) a second lens in which a scattering diffraction limiting aperture is disposed on the front focal plane;
(E) P _OSF × Q _OSF arranged on the rear focal plane of the second lens and arranged in a two-dimensional matrix along the X and Y directions (where P _OSF and Q _OSF are arbitrary positive numbers) Of M) from the m-th order to the m′-th order along the X direction based on the conjugate image of the two-dimensional image generated by the second lens. (Where m and m ′ are integers, M is a positive integer), and N sets from the nth order to the n′th order along the Y direction (where n and n ′ are integers, N Is a positive integer), a sum, an oversampling filter that generates M × N sets of diffracted light,
(F) a third lens having an oversampling filter disposed on its front focal plane;
(G) A spatial filter that is arranged on the rear focal plane of the third lens and has a total of M × N opening / closing controllable openings, M in the X direction and N in the Y direction. ,
(H) a fourth lens having a spatial filter disposed on its front focal plane, and
(I) a fifth lens whose front focal point is located at the rear focal point of the fourth lens;
Consists of.

The three-dimensional image display apparatus according to the 6A aspect of the present invention for achieving the first object includes a light source and an optical system,
The optical system is
(A) a one-dimensional spatial light modulator that generates a one-dimensional image; a scanning optical system that generates a two-dimensional image by two-dimensionally developing the one-dimensional image generated by the one-dimensional spatial light modulator; A two-dimensional image forming apparatus comprising a diffracted light generating means that is arranged on a generation surface of a dimensional image and generates diffracted light of a plurality of diffraction orders for each pixel;
(B) a first lens in which diffracted light generating means is disposed on the front focal plane;
(C) a scattering diffraction limiting aperture that is disposed on the rear focal plane of the first lens and allows only diffracted light of a predetermined diffraction order to pass;
(D) a second lens in which a scattering diffraction limiting aperture is disposed on the front focal plane;
(E) P _OSF × Q _OSF arranged on the rear focal plane of the second lens and arranged in a two-dimensional matrix along the X and Y directions (where P _OSF and Q _OSF are arbitrary positive numbers) Of M) from the m-th order to the m′-th order along the X direction based on the conjugate image of the two-dimensional image generated by the second lens. (Where m and m ′ are integers, M is a positive integer), and N sets from the nth order to the n′th order along the Y direction (where n and n ′ are integers, N Is a positive integer), a sum, an oversampling filter that generates M × N sets of diffracted light,
(F) a third lens having an oversampling filter disposed on its front focal plane;
(G) A spatial filter that is arranged on the rear focal plane of the third lens and has a total of M × N opening / closing controllable openings, M in the X direction and N in the Y direction. ,
(H) a fourth lens having a spatial filter disposed on its front focal plane, and
(I) a fifth lens whose front focal point is located at the rear focal point of the fourth lens;
Consists of.

The three-dimensional image display apparatus according to the seventh aspect of the present invention for achieving the first object includes a light source and an optical system.
The optical system is
(A) a two-dimensional image forming apparatus having a plurality of pixels and generating a two-dimensional image based on light from a light source;
(B) An optical element having an optical power for refracting incident light and condensing it at approximately one point is arranged in a two-dimensional matrix, and has a function as a phase grating that modulates the phase of transmitted light; An optical device that emits spatial frequencies in an incident two-dimensional image along diffraction angles corresponding to a plurality of diffraction orders;
(C) Fourier transform image forming means for generating a Fourier transform image having a number corresponding to the plurality of diffraction orders by Fourier transforming a spatial frequency in a two-dimensional image emitted from the optical device;
(D) Fourier transform image selection means for selecting a Fourier transform image corresponding to a desired diffraction order among Fourier transform images generated in a number corresponding to the plurality of diffraction orders, and
(E) conjugate image forming means for forming a conjugate image of the Fourier transform image selected by the Fourier transform image selection means;
Consists of.

The three-dimensional image display apparatus according to the 8A aspect of the present invention for achieving the first object includes a light source and an optical system.
The optical system is
(A) a two-dimensional image forming apparatus having a plurality of pixels and generating a two-dimensional image based on light from a light source;
(B) P _OD × Q _OD optical elements having an optical power that refracts incident light and collects it at approximately one point in a two-dimensional matrix along the X and Y directions (however, P _OD and Q _OD is an arbitrary positive integer) array and has a function as a phase grating that modulates the phase of transmitted light. A spatial frequency in an incident two-dimensional image is expressed by a plurality of diffraction orders (total number M × N). An optical device that emits light along a diffraction angle corresponding to
(C) a first lens in which the focal point of the optical element constituting the optical device is located on the front focal plane;
(D) A spatial filter that is arranged on the rear focal plane of the first lens and has a total of M × N open / close controllable openings, M in the X direction and N in the Y direction. ,
(E) a second lens having a spatial filter disposed on its front focal plane, and
(F) a third lens whose front focal point is located at the rear focal point of the second lens;
Consists of.

The three-dimensional image display apparatus according to the ninth aspect of the present invention for achieving the first object includes a light source and an optical system,
The optical system is
(A) It has a plurality of pixels, the light from the light source is modulated by each pixel to generate a two-dimensional image, and the spatial frequency in the generated two-dimensional image corresponds to the plurality of diffraction orders generated from each pixel Light modulating means for emitting along the diffraction angle,
(B) Fourier transform the spatial frequency in the two-dimensional image emitted from the light modulation means to generate a number of Fourier transform images corresponding to a plurality of diffraction orders generated from the pixels, An image limiting / generating unit that selects only a predetermined Fourier transform image, and further performs inverse Fourier transform on the selected Fourier transform image to form a conjugate image of the two-dimensional image generated by the light modulation unit,
(C) a light beam traveling direction changing unit that changes a traveling direction of a light beam emitted from the image limiting / generating unit, and
(D) Imaging means for forming an image of the light beam emitted from the light beam traveling direction changing means;
Consists of.

A three-dimensional image display apparatus according to the 10A aspect of the present invention for achieving the first object includes a light source and an optical system.
The optical system is
(A) It has openings arranged in a two-dimensional matrix along the X and Y directions, and generates a two-dimensional image by controlling the passage, reflection, or diffraction of light from the light source for each opening, A two-dimensional image forming apparatus that generates diffracted light of a plurality of diffraction orders for each aperture based on the two-dimensional image;
(B) a first lens in which a two-dimensional image forming apparatus is disposed on the front focal plane;
(C) a scattering diffraction limiting aperture that is disposed on the rear focal plane of the first lens and allows only diffracted light of a predetermined diffraction order to pass;
(D) a second lens in which a scattering diffraction limiting aperture is disposed on the front focal plane;
(E) a light ray traveling direction changing unit that is arranged behind the second lens and changes the traveling direction of the light emitted from the second lens; and
(F) a third lens that forms an image of the light beam emitted from the light beam traveling direction changing means;
Consists of.

A three-dimensional image display apparatus according to the 11A aspect of the present invention for achieving the first object includes a light source and an optical system,
The optical system is
(A) a one-dimensional spatial light modulator that generates a one-dimensional image; a scanning optical system that generates a two-dimensional image by two-dimensionally developing the one-dimensional image generated by the one-dimensional spatial light modulator; A two-dimensional image forming apparatus comprising a diffracted light generating means that is arranged on a generation surface of a dimensional image and generates diffracted light of a plurality of diffraction orders for each pixel;
(B) a first lens in which diffracted light generating means is disposed on the front focal plane;
(C) a scattering diffraction limiting aperture that is disposed on the rear focal plane of the first lens and allows only diffracted light of a predetermined diffraction order to pass;
(D) a second lens in which a scattering diffraction limiting aperture is disposed on the front focal plane;
(E) a light ray traveling direction changing unit that is arranged behind the second lens and changes the traveling direction of the light emitted from the second lens; and
(F) a third lens that forms an image of the light beam emitted from the light beam traveling direction changing means;
Consists of.

A three-dimensional image display apparatus according to the twelfth aspect of the present invention for achieving the first object described above includes a light source that emits light from a plurality of discrete light emission positions, and an optical system. Has
The optical system is
(A) A plurality of pixels, which are sequentially emitted from different light emission positions of the light source, modulate light with different incident directions by each pixel to generate a two-dimensional image, and a spatial frequency in the generated two-dimensional image A light modulating means for emitting light along a diffraction angle corresponding to a plurality of diffraction orders generated from each pixel, and
(B) A Fourier transform image in which the spatial frequency in the two-dimensional image emitted from the light modulation means is Fourier transformed to generate a Fourier transform image of a number corresponding to the plurality of diffraction orders, and the Fourier transform image is formed. Forming means,
Consists of.

A three-dimensional image display apparatus according to the thirteenth aspect of the present invention for achieving the first object described above includes a light source that emits light from a plurality of discrete light emission positions, and an optical system. With
The optical system is
(A) It has openings arranged in a two-dimensional matrix along the X and Y directions, and is sequentially emitted from different light emission positions of the light source, and controls the passage or reflection of light having different incident directions for each opening. A two-dimensional image forming apparatus that generates a two-dimensional image and generates diffracted light of a plurality of diffraction orders for each aperture based on the two-dimensional image,
(B) a first lens in which a two-dimensional image forming apparatus is disposed on the front focal plane;
(C) a second lens whose front focal plane is located on the rear focal plane of the first lens; and
(D) a third lens whose front focal plane is located on the rear focal plane of the second lens;
Consists of.

  In the three-dimensional image display device according to the first to thirteenth aspects of the present invention, the transflective mirror that changes (changes) the traveling direction of the light beam emitted from the optical system is further provided. I have. The transflective mirror may be a flat mirror having a flat reflecting surface or a concave mirror having a concave reflecting surface.

  Here, the semi-transmissive mirror is a transparent or semi-transparent plate-like, sheet-like or film-like substrate that is transparent to the light emitted from the optical system. It can be obtained by attaching a metal thin film or the like, or by forming a dielectric multilayer film, a dielectric highly reflective film, a cut filter, a dichroic filter, a metal thin film, or the like on the substrate. Examples of the base material include a glass substrate, a plastic substrate, a plastic sheet, and a plastic film. Examples of the plastic material constituting the plastic film include polyethersulfone (PES) film, polyethylene naphthalate (PEN) film, polyimide (PI) film, polyethylene terephthalate (PET) film, plastic substrate and plastic Examples of the plastic material constituting the sheet include polymethyl methacrylate resin (PMMA), polycarbonate resin (PC), polyarylate resin (PAR), polyethylene terephthalate resin (PET), acrylic resin, and ABS resin. Furthermore, examples of the base material include those in which the above-mentioned various films are bonded to a glass substrate, and those in which a polyimide resin layer, an acrylic resin layer, a polystyrene resin layer, and a silicone rubber layer are formed on the glass substrate. . Alternatively, examples of the base material include windshields of various vehicles such as automobiles and window glass of cockpits of aircraft. In such a form, a head-up display that can display a stereoscopic image ( HUD) can be configured.

  In the three-dimensional image display device according to the first to thirteenth aspects of the present invention, the light source and the optical system exist on the extension of the path of the light beam whose traveling direction is changed by the transflective mirror. It is preferable to adopt a configuration that does not. Here, the path of the light beam emitted from the optical system and before colliding with the semi-transmissive mirror is called “path-1”, and the path of the light beam that collides with the semi-transmissive mirror and is reflected and travels toward the observer. Called “Route-2”. “Extension of the path of the light beam” refers to a path that travels along the path-2 from the observer side, extends straight through the semi-transmissive mirror, and extends to the back of the semi-transmissive mirror. Alternatively, a configuration in which the image of the light source does not exist (that is, a configuration in which the image of the light source is concealed from the observer) on the extension of the path of the light beam whose traveling direction has been changed by the transflective mirror. Preferably, in order to achieve such a configuration, it is only necessary to optimize the arrangement of the transflective mirrors or to arrange a shielding member (for example, a partition) made of an opaque material to extend the path of the light beam. .

  In each of the three-dimensional image display devices according to the first to thirteenth to thirteenth aspects of the present invention, instead of including a transflective mirror that changes the traveling direction of the light beam emitted from the optical system, the light beam is emitted from the optical system. It is also possible to change the traveling direction of the light beam and to include a light beam control means for controlling the light collection state at the observation point of the light beam emitted from the optical system. Aim can be achieved. In addition, the three-dimensional image display apparatus having such a configuration is referred to as a three-dimensional image display apparatus according to the first to thirteenth aspects of the present invention.

  In the three-dimensional image display device according to the first to thirteenth to thirteenth aspects of the present invention, the light beam control means can be constituted by a concave mirror (a total reflection type mirror or a semi-transmission type mirror) having a concave reflection surface. . Alternatively, in the three-dimensional image display device according to the first to thirteenth to thirteenth aspects of the present invention, the light beam control means includes a lens on which a light beam emitted from the optical system is incident, and a light beam emitted from the lens. Can be composed of a mirror (a flat mirror or a concave mirror, and a total reflection type mirror or a semi-transmission type mirror). Alternatively, the light beam control means is constituted by a mirror (a flat mirror or a concave mirror, and a total reflection type mirror or a semi-transmission type mirror), and the light beam control means further includes a detection means for detecting an observation point. The position of the mirror can be controlled based on the observation point detection result of the detection means. That is, when the observer moves, the position of the mirror may be controlled in accordance with (in synchronization with) the movement of the observer. Alternatively, the light control means includes a lens on which a light beam emitted from the optical system is incident, and a mirror on which the light beam emitted from the lens is incident (a flat mirror or a concave mirror, and a total reflection type mirror or a semi-transmission type). The light beam control means further includes a detection means for detecting the observation point, and controls the condensing state of the lens based on the observation point detection result of the detection means. it can. That is, when the observer moves, the condensing state of the lens may be controlled in accordance with (in synchronization with) the movement of the observer. Note that the light beam to be emitted from the optical system may be controlled based on the observation point detection result of the detection means. That is, when the observer moves, the light beam to be emitted from the optical system may be controlled in accordance with (in synchronization with) the movement of the observer. The lens can be composed of, for example, a biconvex lens, a plano-convex lens, or a meniscus convex lens, can be composed of a Fresnel lens, or can be composed of a combination of these various convex lenses. Can also be configured by combining a concave lens and these various convex lenses. The detection means can be composed of, for example, a camera equipped with a CCD element. The detection means may be disposed essentially anywhere as long as the observation point can be detected (specifically, for example, as long as the face and pupil of the observer can be detected). For example, the three-dimensional image display device Near the inside of the optical system or inside the optical system.

  The three-dimensional image display device according to the 1A aspect of the present invention and the three-dimensional image display device according to the 1B aspect of the present invention, including the above-mentioned preferred forms and configurations, are collectively referred to as “first of the present invention. It is called a “three-dimensional image display device according to the embodiment”. Similarly, the three-dimensional image display device according to the jAth aspect of the present invention including the above-described preferred form and configuration and the three-dimensional image display apparatus according to the jBth aspect of the present invention (where j = 2, 3,... 13) is collectively referred to as “a three-dimensional image display device according to the jth aspect of the present invention” for convenience.

  In the three-dimensional image display device according to the first aspect of the present invention, the conjugate image forming means is generated by the light modulation means by performing inverse Fourier transform on the Fourier transform image selected by the Fourier transform image selection means. It is preferable that an inverse Fourier transform unit for forming a real image of a two-dimensional image is included.

  In the three-dimensional image display device according to the first aspect of the present invention including the above-described preferred configuration, the light modulation means is composed of a two-dimensional spatial light modulator having a plurality of pixels arranged two-dimensionally. In this case, the two-dimensional spatial light modulator may be a liquid crystal display device (more specifically, a transmissive or reflective liquid crystal display device), or two-dimensional spatial light. It is preferable to adopt a configuration in which a movable mirror is provided in each opening of the modulator (a configuration composed of a two-dimensional MEMS in which the movable mirrors are arranged in a two-dimensional matrix). Here, the planar shape of the opening is preferably rectangular. When the planar shape of the opening is rectangular, Fraunhofer diffraction occurs, and M × N sets of diffracted light are generated as described later. That is, such an aperture forms an amplitude grating that periodically modulates the amplitude (intensity) of the incident light wave and obtains a light amount distribution that matches the light transmittance distribution of the grating.

Alternatively, in the three-dimensional image display device according to the first aspect of the present invention including the above-described preferable configuration and form, the light modulation means includes:
(A-1) a one-dimensional spatial light modulator that generates a one-dimensional image;
(A-2) a scanning optical system that two-dimensionally develops a one-dimensional image generated by a one-dimensional spatial light modulator and generates a two-dimensional image; and
(A-3) a grating filter that is arranged on a generation surface of a two-dimensional image and emits spatial frequencies in the generated two-dimensional image along diffraction angles corresponding to a plurality of diffraction orders;
It can be set as the form which consists of. The grating filter may be composed of an amplitude grating, or may be composed of a phase grating that modulates the phase while modulating the phase of the amount of transmitted light, that is, the amplitude (intensity) of light is unchanged. .

  Furthermore, in the three-dimensional image display device according to the first aspect of the present invention including the above-described preferred configuration and configuration, the Fourier transform image forming means is formed of a lens, and the light modulation means is disposed on the front focal plane of the lens. In addition, a Fourier transform image selection means can be arranged on the rear focal plane of this lens.

  Further, in the three-dimensional image display device according to the first aspect of the present invention including the preferred configuration and form described above, the Fourier transform image selecting means has a number of opening / closing controllable openings corresponding to the plurality of diffraction orders. In this case, the Fourier transform image selection means can be a liquid crystal display device (more specifically, a transmissive or reflective liquid crystal display device). The movable mirror may be formed of a two-dimensional type MEMS arranged in a two-dimensional matrix. The Fourier transform image selection means is configured to select a Fourier transform image corresponding to a desired diffraction order by opening a desired opening in synchronization with the generation timing of a two-dimensional image by the light modulation means. It can be.

  Furthermore, in the three-dimensional image display device according to the first aspect of the present invention including the above-described preferable configuration and form, the spatial frequency in the two-dimensional image is the carrier frequency (carrier frequency) as the spatial frequency of the pixel structure. A configuration corresponding to image information can be adopted.

  In the three-dimensional image display device according to the second aspect of the present invention, the two-dimensional image forming device includes a liquid crystal display device (more specifically, a transmissive type) having two-dimensionally arranged P × Q pixels. Or a reflection type liquid crystal display device, and each pixel may be provided with an opening, or each opening in the two-dimensional image forming apparatus is provided with a movable mirror (movable) It is preferable that the mirror is configured of a two-dimensional type MEMS disposed in each of the openings arranged in a two-dimensional matrix. Here, the planar shape of the opening is preferably rectangular. When the planar shape of the opening is rectangular, Fraunhofer diffraction occurs, and M × N sets of diffracted light are generated. That is, an amplitude grating is formed by the openings.

  In the three-dimensional image display device according to the second aspect of the present invention including the above preferable configuration and form, the spatial filter is a liquid crystal display device having M × N pixels (more specifically, a transmission type or a reflection type). Liquid crystal display device) or a two-dimensional MEMS in which movable mirrors are arranged in a two-dimensional matrix. In addition, the spatial filter can be configured to open a desired opening in synchronization with the generation timing of the two-dimensional image by the two-dimensional image forming apparatus.

  In the three-dimensional image display device according to the third aspect of the present invention, the one-dimensional spatial light modulator may be configured to generate a one-dimensional image by diffracting light from the light source.

  In the three-dimensional image display device according to the third aspect of the present invention including the above preferred configuration, the spatial filter is a liquid crystal display device having M × N pixels (more specifically, a transmissive or reflective type). A liquid crystal display device), or a two-dimensional MEMS in which movable mirrors are arranged in a two-dimensional matrix. In addition, the spatial filter can be configured to open a desired opening in synchronization with the generation timing of the two-dimensional image.

  Furthermore, in the three-dimensional image display device according to the third aspect of the present invention including the above-described preferable configuration and form, a member (another member that causes anisotropic light diffusion) is further provided behind the third lens. (An anisotropic diffusion filter, an anisotropic diffusion sheet, or an anisotropic diffusion film) may be provided.

  In the three-dimensional image display device according to the fourth aspect of the present invention, the conjugate image forming means is generated by the image limiting / generating means by performing inverse Fourier transform on the Fourier transform image selected by the Fourier transform image selecting means. It is preferable that an inverse Fourier transform unit that forms a real image of a conjugate image of the two-dimensional image is included.

In the three-dimensional image display device according to the fourth aspect of the present invention including the above-mentioned preferred configuration, the light modulation means is composed of a two-dimensional spatial light modulator having a plurality of pixels arranged two-dimensionally. Can be configured to have an opening. In this case, the two-dimensional spatial light modulator is replaced with a liquid crystal display device (more specifically, a transmissive or reflective liquid crystal display device), or a two-dimensional space. It is preferable to adopt a configuration in which a movable mirror is provided in each opening of the optical modulator (a configuration composed of a two-dimensional type MEMS in which the movable mirrors are arranged in a two-dimensional matrix). Here, the planar shape of the opening is preferably rectangular. When the planar shape of the opening is rectangular, Fraunhofer diffraction occurs, and M ₀ × N ₀ sets of diffracted light are generated. That is, such an aperture forms an amplitude grating that periodically modulates the amplitude (intensity) of the incident light wave and obtains a light amount distribution that matches the light transmittance distribution of the grating.

Alternatively, in the three-dimensional image display device according to the fourth aspect of the present invention including the above-described preferred configuration and form, the light modulation means
(A-1) a one-dimensional spatial light modulator that generates a one-dimensional image;
(A-2) a scanning optical system that two-dimensionally develops a one-dimensional image generated by a one-dimensional spatial light modulator and generates a two-dimensional image; and
(A-3) a grating filter that is arranged on a generation surface of a two-dimensional image and emits spatial frequencies in the generated two-dimensional image along diffraction angles corresponding to a plurality of diffraction orders;
It can be set as the form which consists of. The grating filter may be composed of an amplitude grating, or may be composed of a phase grating that modulates the phase while modulating the phase of the amount of transmitted light, that is, the amplitude (intensity) of light is unchanged. .

Furthermore, in the three-dimensional image display device according to the fourth aspect of the present invention including the preferred configuration and form described above, the image restriction / generation unit includes:
(B-1) two lenses, and
(B-2) a scattering diffraction limiting aperture disposed between the two lenses and allowing only the predetermined Fourier transform image to pass through;
It can be set as the form comprised from.

  In the three-dimensional image display device according to the fourth aspect of the present invention including the preferred configuration and configuration described above, the oversampling filter is a diffracted light generating member, more specifically, for example, a lattice filter. It can be. Note that the grating filter may be composed of an amplitude grating or a phase grating.

  Furthermore, in the three-dimensional image display device according to the fourth aspect of the present invention including the above-described preferred configuration and form, the Fourier transform image forming means is composed of a lens, and an oversampling filter is disposed on the front focal plane of this lens. In addition, a Fourier transform image selection means can be arranged on the rear focal plane of this lens.

  Further, in the three-dimensional image display device according to the fourth aspect of the present invention including the preferred configuration and configuration described above, the Fourier transform image selection means has a number corresponding to a plurality of diffraction orders generated from each aperture region. In this case, the Fourier transform image selection means is formed of a liquid crystal display device (more specifically, a transmissive or reflective liquid crystal display device). Alternatively, the movable mirror may be formed of a two-dimensional type MEMS arranged in a two-dimensional matrix. The Fourier transform image selection means is configured to select a Fourier transform image corresponding to a desired diffraction order by opening a desired opening in synchronization with the generation timing of a two-dimensional image by the light modulation means. It can be.

  Furthermore, in the three-dimensional image display device according to the fourth aspect of the present invention including the above preferred configuration and form, the spatial frequency in the two-dimensional image corresponds to image information in which the spatial frequency of the pixel structure is the carrier frequency. Furthermore, the spatial frequency in the conjugate image of the two-dimensional image may be a spatial frequency obtained by removing the spatial frequency of the pixel structure from the spatial frequency in the two-dimensional image. . That is, it is obtained as first-order diffraction using the 0th-order diffraction of the plane wave component as the carrier frequency, and the spatial frequency less than half the spatial frequency of the pixel structure (aperture structure) of the light modulation means is the image limiting / generating means. Or alternatively passes through a scattering diffraction limiting aperture. All the spatial frequencies displayed on the light modulation means or the two-dimensional image forming apparatus described later are transmitted.

In the three-dimensional image display device according to the fifth aspect of the present invention, the two-dimensional image forming device includes a liquid crystal display device (more specifically, a transmissive type) having two-dimensionally arranged P × Q pixels. Or a reflection type liquid crystal display device), each pixel is provided with an opening, and P _OSF > P, Q _OSF > Q can be satisfied, or the two-dimensional image forming apparatus has , P × Q openings are provided, and each opening is provided with a movable mirror (consisting of a two-dimensional MEMS in which the movable mirrors are arranged in respective openings arranged in a two-dimensional matrix. Configuration), P _OSF > P, Q _OSF > Q can be satisfied. The planar shape of the opening is preferably rectangular. When the planar shape of the opening is rectangular, Fraunhofer diffraction occurs, and M ₀ × N ₀ sets of diffracted light are generated. That is, an amplitude grating is formed by the openings. Further, the oversampling filter can be formed of a diffracted light generating member, more specifically, for example, a grating filter. Note that the grating filter may be composed of an amplitude grating or a phase grating.

  In the three-dimensional image display device according to the fifth aspect of the present invention including the above-described preferred configuration and form, the spatial filter is a liquid crystal display device having M × N pixels (more specifically, a transmissive type or a reflective type). Liquid crystal display device) or a two-dimensional MEMS in which movable mirrors are arranged in a two-dimensional matrix. In addition, the spatial filter can be configured to open a desired opening in synchronization with the generation timing of the two-dimensional image by the two-dimensional image forming apparatus.

In the three-dimensional image display device according to the sixth aspect of the present invention, the one-dimensional spatial light modulator has P pixels along the X direction, and diffracts light from the light source to display a one-dimensional image. And form that satisfies P _OSF > P. The oversampling filter can be in the form of a diffracted light generating member, more specifically a grating filter, for example. Note that the grating filter may be composed of an amplitude grating or a phase grating.

  In the three-dimensional image display device according to the sixth aspect of the present invention including the above preferable configuration and configuration, the spatial filter is a liquid crystal display device having M × N pixels (more specifically, a transmissive type or a reflective type). Liquid crystal display device) or a two-dimensional MEMS in which movable mirrors are arranged in a two-dimensional matrix. In addition, the spatial filter can be configured to open a desired opening in synchronization with the generation timing of the two-dimensional image.

In the three-dimensional image display device according to the fourth to sixth aspects of the present invention including the various preferable configurations and forms described above, P _{OSF is used} as the structure of the lattice filter constituting the oversampling filter. _XQ A structure (phase grating type) in which _OSF concave portions are formed in a two-dimensional matrix can be exemplified. Here, the concave portion corresponds to the opening region. When the planar shape of the opening region (concave portion) is, for example, rectangular, Fraunhofer diffraction occurs, and M × N sets of diffracted light are generated. Further, as described above, it is preferable that P _OSF > P, Q _OSF > Q is satisfied, but more specifically, 1 <P _OSF / P ≦ 4 and 1 <Q _OSF / Q ≦ 4 are exemplified. Can do.

  In the three-dimensional image display apparatus according to the seventh aspect of the present invention, the conjugate image forming means generates the two-dimensional image forming apparatus by performing inverse Fourier transform on the Fourier transform image selected by the Fourier transform image selecting means. It is preferable that an inverse Fourier transform unit that forms a real image of the two-dimensional image is included.

  In the three-dimensional image display device according to the seventh aspect of the present invention including the above-described preferable configuration, the two-dimensional image forming device is configured from a liquid crystal display device (more specifically, a transmissive or reflective liquid crystal display device). It is preferable to do.

Alternatively, in the three-dimensional image display device according to the seventh aspect of the present invention including the above-described preferable configuration, the two-dimensional image forming device includes:
(A-1) a one-dimensional image forming apparatus for generating a one-dimensional image, and
(A-2) a scanning optical system that two-dimensionally develops a one-dimensional image generated by a one-dimensional image forming apparatus and generates a two-dimensional image;
It can be set as the form which consists of.

  Furthermore, in the three-dimensional image display device according to the seventh aspect of the present invention, including the preferred configuration and form described above, the Fourier transform image forming means comprises a lens; an optical device is provided on the front focal plane of the lens. The focal point of the optical element to be constructed is located; a configuration in which Fourier transform image selection means is arranged on the rear focal plane of the lens can be adopted.

  Further, in the three-dimensional image display device according to the seventh aspect of the present invention including the preferred configuration and form described above, the Fourier transform image selecting means has a number of opening / closing controllable openings corresponding to the plurality of diffraction orders. In this case, the Fourier transform image selection means can be a liquid crystal display device (more specifically, a transmissive or reflective liquid crystal display device). The movable mirror may be formed of a two-dimensional type MEMS arranged in a two-dimensional matrix. The Fourier transform image selection means selects a Fourier transform image corresponding to a desired diffraction order by opening a desired opening in synchronization with the generation timing of the two-dimensional image by the two-dimensional image forming apparatus. It can be set as the structure to do.

  Furthermore, in the three-dimensional image display device according to the seventh aspect of the present invention including the above preferred configuration and form, the spatial frequency in the two-dimensional image is the carrier frequency of the spatial frequency of the pixel structure in the two-dimensional image forming device. It can be set as the structure corresponded to image information.

In the three-dimensional image display apparatus according to the eighth aspect of the present invention, the two-dimensional image forming apparatus includes two-dimensionally arranged P × Q pixels (where P _OD ≧ P, Q _OD ≧ Q). The liquid crystal display device (more specifically, a transmissive or reflective liquid crystal display device) can be used. As a more specific relationship between P _OD and P, Q _OD and Q, can be exemplified _{1 ≦ P OD / P ≦ 4,1} ≦ Q OD / Q ≦ 4.

Alternatively, in the three-dimensional image display apparatus according to the eighth aspect of the present invention, the two-dimensional image forming apparatus includes:
(A-1) a one-dimensional image forming apparatus for generating a one-dimensional image, and
(A-2) a scanning optical system that two-dimensionally develops a one-dimensional image generated by a one-dimensional image forming apparatus and generates a two-dimensional image;
It can be set as the structure which consists of. In this case, the one-dimensional image forming apparatus can be configured to generate a one-dimensional image by diffracting light from the light source. Furthermore, a member (an anisotropic diffusion filter, an anisotropic diffusion sheet, or an anisotropic diffusion film) that causes anisotropic light diffusion is further disposed behind the third lens. It can also be in the form.

  In the three-dimensional image display device according to the eighth aspect of the present invention including the above preferable configuration and form, the spatial filter is a liquid crystal display device having M × N pixels (more specifically, a transmission type or a reflection type). Liquid crystal display device) or a two-dimensional MEMS in which movable mirrors are arranged in a two-dimensional matrix. In addition, the spatial filter can be configured to open a desired opening in synchronization with the generation timing of the two-dimensional image by the two-dimensional image forming apparatus.

  In the three-dimensional image display device according to the seventh aspect and the eighth aspect of the present invention including the various preferable configurations and forms described above, each pixel in the two-dimensional image forming apparatus has an opening having a rectangular planar shape. Have. The following configuration can be exemplified as a specific structure of the optical device in the three-dimensional image display device according to the seventh aspect and the eighth aspect of the present invention. That is, it is preferable that the planar shape of the optical element is the same as or similar to the planar shape of the corresponding pixel aperture. Each optical element is composed of a convex lens having positive optical power, or is composed of a concave lens having negative optical power, or is composed of a Fresnel lens having positive optical power. It is also desirable that the lens is composed of a Fresnel lens having negative optical power. In other words, each optical element is composed of a refractive lattice element. The optical device is composed of a kind of microlens array, and examples of the material constituting the optical device include glass and plastic. The optical device can be manufactured based on a known method for manufacturing a microlens array. The optical device is disposed adjacent to the rear of the two-dimensional image forming apparatus. Thus, by arranging the optical device adjacent to the rear of the two-dimensional image forming apparatus, the influence of the diffraction phenomenon caused by the two-dimensional image forming apparatus can be ignored. Alternatively, for example, two convex lenses are arranged between the two-dimensional image forming apparatus and the optical apparatus, the two-dimensional image forming apparatus is arranged on the front focal plane of one convex lens, and the rear focal point of one convex lens. Alternatively, the front focal point of the other convex lens may be positioned on the rear focal plane of the other convex lens, and the optical device may be disposed on the rear focal plane of the other convex lens. Generally, when the diffraction grating is classified into two categories, the amplitude (intensity) of the incident light wave is periodically modulated, and the amplitude grating that obtains a light quantity distribution that matches the light transmittance distribution of the grating and the phase of the transmitted light quantity are modulated. That is, it can be classified as a phase grating that modulates the phase while maintaining the amplitude (intensity) of light as it is. However, the three-dimensional image display device according to the seventh aspect and the eighth aspect of the present invention is suitable. Thus, the optical device functions as the latter phase grating.

In the three-dimensional image display device according to the ninth aspect of the present invention, the light modulation means is composed of a two-dimensional spatial light modulator having a plurality of pixels arranged two-dimensionally, and each pixel has an opening. In this case, the two-dimensional spatial light modulator is replaced with a liquid crystal display device (more specifically, a transmissive or reflective liquid crystal display device) or each opening of the two-dimensional spatial light modulator. It is preferable to adopt a configuration in which a movable mirror is provided (a configuration composed of a two-dimensional type MEMS in which the movable mirrors are arranged in a two-dimensional matrix). Here, the planar shape of the opening is preferably rectangular. When the planar shape of the opening is rectangular, Fraunhofer diffraction occurs, and M ₀ × N ₀ sets of diffracted light are generated. That is, such an aperture forms an amplitude grating that periodically modulates the amplitude (intensity) of the incident light wave and obtains a light amount distribution that matches the light transmittance distribution of the grating.

Alternatively, in the three-dimensional image display device according to the ninth aspect of the present invention including the above preferred configuration and form, the light modulation means
(A-1) a one-dimensional spatial light modulator that generates a one-dimensional image;
(A-2) a scanning optical system that two-dimensionally develops a one-dimensional image generated by a one-dimensional spatial light modulator and generates a two-dimensional image; and
(A-3) a grating filter that is arranged on a generation surface of a two-dimensional image and emits spatial frequencies in the generated two-dimensional image along diffraction angles corresponding to a plurality of diffraction orders;
It can be set as the form which consists of. The grating filter may be composed of an amplitude grating, or may be composed of a phase grating that modulates the phase while modulating the phase of the amount of transmitted light, that is, the amplitude (intensity) of light is unchanged. .

Furthermore, in the three-dimensional image display device according to the ninth aspect of the present invention including the preferred configuration and configuration described above, the image restriction / generation means includes:
(B-1) a first lens that Fourier-transforms the spatial frequency in the two-dimensional image emitted from the light modulation means to generate a number of Fourier transform images corresponding to a plurality of diffraction orders generated from each pixel;
(B-2) a scattering diffraction limiting aperture that is disposed closer to the light beam traveling direction changing means than the first lens and selects only a predetermined Fourier transform image of the Fourier transform image; and
(B-3) A conjugate image of the two-dimensional image generated by the light modulation means is disposed by being closer to the light beam traveling direction changing means than the scattering diffraction limiting aperture, and inverse Fourier transforming the selected Fourier transform image. A second lens to be formed,
Consists of
A scattering diffraction limiting aperture may be arranged on the rear focal plane of the first lens and on the front focal plane of the second lens.

  Further, in the three-dimensional image display device according to the ninth aspect of the present invention including the various preferable configurations and forms described above, the light ray traveling direction changing means changes the angle of the emitted light beam with respect to the incident light beam. Reflective optical means that can be (changed), specifically, for example, can comprise a mirror, or can also change (change) the angle of the outgoing light with respect to the incoming light ) Transmission optical means, specifically, for example, a prism.

  Furthermore, in the three-dimensional image display device according to the ninth aspect of the present invention including the above various preferred configurations and forms, the spatial frequency in the two-dimensional image is image information in which the spatial frequency of the pixel structure is the carrier frequency. Furthermore, the spatial frequency in the conjugate image of the two-dimensional image is a spatial frequency obtained by removing the spatial frequency of the pixel structure from the spatial frequency in the two-dimensional image. Can do. That is, it is obtained as first-order diffraction using the 0th-order diffraction of the plane wave component as the carrier frequency, and the spatial frequency less than half the spatial frequency of the pixel structure (aperture structure) of the light modulation means is the image limiting / generating means. Or alternatively passes through a scattering diffraction limiting aperture. All the spatial frequencies displayed on the light modulation means or the two-dimensional image forming apparatus described later are transmitted.

  In the three-dimensional image display device according to the tenth aspect of the present invention, the two-dimensional image forming device is a liquid crystal display device (more specifically, a transmissive type) having two-dimensionally arranged P × Q pixels. Or a reflection type liquid crystal display device), and each pixel may be provided with an opening, or the two-dimensional image forming apparatus is provided with P × Q openings, Each opening may be provided with a movable mirror (the movable mirror is composed of a two-dimensional type MEMS disposed in each of the openings arranged in a two-dimensional matrix). The planar shape of the opening is preferably rectangular. When the planar shape of the opening is rectangular, Fraunhofer diffraction occurs, and M × N sets of diffracted light are generated. That is, an amplitude grating is formed by the openings.

  In the three-dimensional image display device according to the eleventh aspect of the present invention, the one-dimensional spatial light modulator has P pixels along the X direction, and diffracts light from the light source to display a one-dimensional image. It can be set as the form to produce | generate.

  In the three-dimensional image display device according to the tenth aspect or the eleventh aspect of the present invention, including the preferred configuration and form described above, the light ray traveling direction changing means changes the angle of the emitted light beam with respect to the incident light beam. Reflective optical means that can be changed (changed), specifically, for example, can be constituted by a mirror, or the angle of the outgoing light beam can be changed (changed) with respect to the incident light beam. Transmissive optical means, specifically, for example, a prism.

  In the description of the three-dimensional image display device according to the ninth aspect to the eleventh aspect of the present invention, the optical axis portion up to the light beam traveling direction changing means is the z-axis, and the orthogonal coordinates in a plane orthogonal to the z-axis Are the x axis and the y axis, the direction parallel to the x axis is the X direction, and the direction parallel to the y axis is the Y direction. The X direction is, for example, the horizontal direction in the image display device, and the Y direction is, for example, the vertical direction in the image display device. Further, the optical axis portion after the light beam traveling direction changing means is the z ′ axis, the orthogonal coordinates in the plane orthogonal to the z ′ axis are the x ′ axis and the y ′ axis, and the direction parallel to the x ′ axis is the X ′ axis. A direction parallel to the “direction, y” axis is defined as a Y ′ direction. The X ′ direction is, for example, the horizontal direction in the image display device, and the Y ′ direction is, for example, the vertical direction in the image display device.

  In the three-dimensional image display device according to the ninth aspect to the eleventh aspect of the present invention, the change of the traveling direction of the light beam by the light beam traveling direction changing unit is based on the light modulation unit (two-dimensional image forming apparatus). It is necessary to synchronize with the generation of the two-dimensional image. Here, after a certain image is formed on the imaging plane described below by the light beam traveling direction changing means, the position of the light beam traveling direction changing means is changed (changed), and the image is formed by the light beam traveling direction changing means. Until the next image is formed on the surface, it is necessary that the operation of the light source is interrupted so that a two-dimensional image is not generated by the light modulation means (two-dimensional image forming apparatus).

As described above, in order to set the position where the image is formed on the image plane to a position arranged in a two-dimensional matrix of S ₀ × T _0, when a mirror is used as the light beam traveling direction changing means, Is composed of a polygon mirror, and the inclination angle of the rotation axis may be controlled while rotating the polygon mirror about the rotation axis. Further, when a prism is employed as the light beam traveling direction changing means, for example, the prism may be rotated (changed) in a desired direction around the z axis. In addition to the conventional prism, for example, a prism made of a liquid crystal lens can be used as the prism. Since the mirror in which the movable mirrors are arranged in a two-dimensional matrix has a pixel structure, a new diffraction image is generated using the pixel structure as a carrier. Cannot be used.

In the dimensional image display device according to the ninth to eleventh aspects of the present invention, when the light beam emitted from the light beam traveling direction changing unit is imaged by the imaging unit or the third lens, the image is displayed. It is preferable that the position where the image is formed (the position in the X′Y ′ plane) is a position arranged in a two-dimensional matrix of S ₀ × T ₀ locations. Here, the number of S ₀ and T ₀ is not limited, but 4 ≦ S ₀ ≦ 11, preferably 7 ≦ S ₀ ≦ 9, for example, and 4 ≦ T ₀ ≦ 11. Preferably, for example, 7 ≦ T ₀ ≦ 9 can be mentioned. The value of S _{0 and} the value of T ₀ may be equal or different. The X′Y ′ plane on which the light beam emitted from the light beam traveling direction changing unit is imaged by the imaging unit or the third lens is hereinafter referred to as an imaging surface.

In the three-dimensional image display device according to the twelfth aspect of the present invention,
(C) conjugate image forming means for forming a conjugate image of the Fourier transform image formed by the Fourier transform image forming means;
Is preferably further provided.

In the three-dimensional image display apparatus according to the twelfth aspect or thirteenth aspect of the present invention, when the number of light emitting positions arranged discretely is LEP _Total , light is emitted from each light emitting position, and light modulating means Alternatively, the number of Fourier transform images generated by light having different incident directions to the two-dimensional image forming apparatus (hereinafter sometimes referred to as illumination light) is (plural diffraction orders) × LEP _Total . Further, the Fourier transform image obtained based on the illumination light is imaged in a spot shape at a discrete position corresponding to each light emission position by the Fourier transform image forming means or the first lens. If a Fourier transform image selection means or a spatial filter, which will be described later, is arranged, the number of Fourier transform images generated by the illumination light finally becomes, for example, LEP _Total . When a plurality of light emission positions arranged in a discrete manner are arranged separated in a two-dimensional matrix, the number of such light emission positions is expressed as “U ₀ × V ₀ ”. Here, U ₀ × V ₀ = LEP _Total .

In the three-dimensional image display device according to the twelfth aspect or the thirteenth aspect of the present invention, the light source can be configured to include a plurality of light emitting elements arranged in a two-dimensional matrix. In this case, if the number of light emitting elements arranged in a two-dimensional matrix is U ₀ '× V ₀ ', U ₀ '= U ₀ and V ₀ ' = V ₀ depending on the specifications of the light source. In some cases, for example, U ₀ '/ 3 = U ₀ and V ₀ ' / 3 = V ₀ . In this case, a lens (for example, a collimator lens) is disposed between the light source and the light modulation unit or the two-dimensional image forming apparatus, and the light source is the front focal plane (or the vicinity of the front focal plane) of this lens. It is preferable that the light is emitted from the lens (illumination light) becomes parallel light (substantially parallel light). Alternatively, in the three-dimensional image display device according to the twelfth aspect or the thirteenth aspect of the present invention, the light source is a light emitting element and light emitted from the light emitting element, and is a light modulation means or two-dimensional. A configuration may be provided that includes a light ray traveling direction changing means for changing the incident direction of light incident on the image forming apparatus. In this case, as the light beam traveling direction changing means, a refractive optical means (for example, a lens, more specifically, for example, which can change (change) the angle of the emitted light with respect to the incident light, for example, A collimator lens or a microlens array), or reflective optical means that can change (change) the position and angle of the emitted light with respect to the incident light (specifically, for example, a mirror, more specifically). Specifically, for example, a polygon mirror, a combination of a polygon mirror and a mirror, a convex mirror composed of a curved surface, a concave mirror composed of a curved surface, a convex mirror composed of a polyhedron, or a concave mirror composed of a polyhedron) Can do.

As described above, in the three-dimensional image display device according to the twelfth aspect or the thirteenth aspect of the present invention, when the light source includes a plurality of light emitting elements arranged in a two-dimensional matrix, It is desirable to dispose each light emitting element so that the emission direction of the light emitted from the light emitting element is different and the incident direction to the light modulation means or the two-dimensional image forming apparatus is different. Further, as described above, when the refractive optical means is adopted as the light beam traveling direction changing means, it is preferable to have a configuration including a plurality of light emitting elements arranged in a two-dimensional matrix. As a result of being able to change the emission direction of the light emitted sequentially from each light emitting element, entering the refractive optical means, and exiting from the refractive optical means, the light modulating means or the two-dimensional image forming apparatus The incident direction of light incident on can be changed. In this case, the emission direction of the light emitted from each light emitting element may be the same or different. On the other hand, as described above, when the reflective optical means is adopted as the light beam traveling direction changing means, the number of light emitting elements may be one, for example, U ₀ . Then, the number of light emission positions when the light is emitted from the reflective optical means may be set to U ₀ × V ₀ = LEP _{Total by} controlling the position of the reflective optical means. Specifically, for example, the inclination angle of the rotation axis may be controlled while rotating the polygon mirror around the rotation axis, or the position of light incident on the mirror from the light emitting element may be controlled. Alternatively, the position of the illumination light emitted from the mirror may be controlled, or the state of the illumination light emitted from the mirror (for example, passing or blocking of the illumination light) may be controlled. As a result, the incident direction of the light incident on the light modulation means or the two-dimensional image forming apparatus can be changed.

  Furthermore, in the three-dimensional image display device according to the twelfth aspect of the present invention including the above-described preferred configuration, the Fourier transform image forming means is composed of a lens (first lens), and the lens (first lens) The light modulation means may be arranged on the front focal plane.

In the three-dimensional image display device according to the twelfth aspect of the present invention, the image formed and imaged by the Fourier transform image forming means corresponds to a plurality of diffraction orders, but based on the low-order diffraction orders. Since the obtained image is bright and the image obtained based on the higher-order diffraction orders is dark, an image with sufficient image quality (for example, a three-dimensional image) can be obtained. However, for further improvement in image quality,
(D) Fourier transform image selection means for selecting a Fourier transform image corresponding to a desired diffraction order among the Fourier transform images generated by the number corresponding to the plurality of diffraction orders;
The Fourier transform image selection means is preferably arranged at a position where the Fourier transform image is formed.

Alternatively, in the three-dimensional image display device according to the thirteenth aspect of the present invention, the image generated and imaged by the first lens corresponds to a plurality of diffraction orders, but the low-order diffraction orders. Since the image obtained based on the above is bright and the image obtained based on the higher diffraction order is dark, it is possible to obtain an image with sufficient image quality (for example, a stereoscopic image). However, for further improvement in image quality,
(E) a spatial filter having a number of openings that can be controlled to be opened and closed corresponding to the number of light emission positions, and located on the rear focal plane of the first lens;
It is preferable to have a configuration further comprising In this case, in the spatial filter, it is desirable to open a desired opening in synchronization with the generation timing of the two-dimensional image by the two-dimensional image forming apparatus. Alternatively,
(E) a scattering diffraction limiting member having a number of openings corresponding to the number of light emission positions and located on the rear focal plane of the first lens;
It is preferable to have a configuration further comprising By disposing the spatial filter or the scattering diffraction limiting member, it is possible to pass only desired diffracted light among the generated diffracted light of a plurality of diffraction orders.

In these cases, the Fourier transform image selection means or the spatial filter, (a LEP _Total, for example, U ₀ × V ₀₎ the number of light emitting positions are numbers (LEP _Total corresponding to, for example, U ₀ × It is desirable to have an opening of V ₀ ). The opening may be controllable to open and close, or may be always open. Alternatively, as a Fourier transform image selection means having an opening that can be opened and closed, a liquid crystal display device (more specifically, a transmissive or reflective liquid crystal display device) can be cited, and a movable mirror is two-dimensional. A two-dimensional MEMS arranged in a matrix can also be mentioned. In the Fourier transform image selection means having an opening that can be opened and closed, the desired opening is opened in synchronization with the generation timing of the two-dimensional image by the light modulation means (two-dimensional image forming apparatus). The Fourier transform image corresponding to the desired diffraction order can be selected. The position of the opening may be a position where a desired Fourier transform image (or diffracted light) in the Fourier transform image (or diffracted light) obtained by the Fourier transform image selecting means or the first lens is formed, The position of the opening corresponds to the light emission positions arranged in a discrete manner.

  The three-dimensional image display device according to the twelfth aspect of the present invention including the preferred configuration described above is generated by the light modulation means by performing inverse Fourier transform on the Fourier transform image formed by the Fourier transform image forming means. It is preferable to further include an inverse Fourier transform unit that forms a real image of the two-dimensional image.

  In the three-dimensional image display device according to the twelfth aspect of the present invention including the above-described preferred configuration, the light modulation means is a two-dimensional image having a plurality of (P × Q) pixels arranged two-dimensionally. Each pixel includes a spatial light modulator, and each pixel may have an opening. In this case, the two-dimensional spatial light modulator is a liquid crystal display device (more specifically, a transmissive or reflective liquid crystal). Display device) or a configuration in which a movable mirror is provided in each opening of the two-dimensional spatial light modulator (a configuration composed of a two-dimensional MEMS in which the movable mirrors are arranged in a two-dimensional matrix). Is preferred. In the three-dimensional image display device according to the thirteenth aspect of the present invention including the preferred configuration described above, the two-dimensional image forming device includes a plurality of (P × Q) pixels arranged two-dimensionally. A liquid crystal display device (more specifically, a transmissive or reflective liquid crystal display device), and each pixel may be provided with an opening, or in a two-dimensional image forming apparatus. Is provided with a plurality of (P × Q) openings, and each opening is provided with a movable mirror (a two-dimensional type in which movable mirrors are arranged in respective openings arranged in a two-dimensional matrix. Of MEMS). Here, the planar shape of the opening is preferably rectangular. When the planar shape of the opening is rectangular, Fraunhofer diffraction occurs, and M × N sets of diffracted light are generated. That is, such an aperture forms an amplitude grating that periodically modulates the amplitude (intensity) of the incident light wave and obtains a light amount distribution that matches the light transmittance distribution of the grating.

  Furthermore, in the three-dimensional image display device according to the twelfth aspect of the present invention including the above-described preferable configuration and form, the spatial frequency in the two-dimensional image corresponds to image information using the spatial frequency of the pixel structure as the carrier frequency. Furthermore, the spatial frequency in the conjugate image of the two-dimensional image to be described later can be a spatial frequency obtained by removing the spatial frequency of the pixel structure from the spatial frequency in the two-dimensional image. . That is, it is obtained as 1st order diffraction using the 0th order diffraction of the plane wave component as a carrier frequency, and the spatial frequency less than half of the spatial frequency of the pixel structure (aperture structure) of the light modulation means is Fourier transform image selection means. Alternatively, it is selected in a spatial filter or alternatively passes through a Fourier transform image selection means or a spatial filter. All the spatial frequencies displayed on the light modulation means or the two-dimensional image forming apparatus are transmitted.

In the three-dimensional image display device according to the twelfth aspect or the thirteenth aspect of the present invention including the preferred configurations and forms described above, the number of U ₀ and V ₀ is not limited, but 4 ≦ U ₀ ≦ 12, preferably 9 ≦ U ₀ ≦ 11, for example, and 4 ≦ V ₀ ≦ 12, preferably 9 ≦ V ₀ ≦ 11, for example. The value of U _{0 and} the value of V ₀ may be equal or different. The plane (XY plane) on which the Fourier transform image is formed by the Fourier transform image forming means may be hereinafter referred to as an image plane.

  In the three-dimensional image display apparatus according to the twelfth or thirteenth aspect of the present invention, a Fourier transform image corresponding to a desired diffraction order is selected by a Fourier transform image selection means or a spatial filter, or The Fourier transform image selection means or the spatial filter is passed through, but the desired diffraction order is not limited, but examples include the zeroth diffraction order.

  In the twelfth aspect or the thirteenth aspect of the present invention including the various preferable configurations and forms described above, examples of the light source in the image display device include a laser, a light emitting diode (LED), and a white light source. it can. An illumination optical system for shaping illumination light may be disposed between the light source and the light modulation means or the two-dimensional image forming apparatus. Depending on the specifications of the image display device, monochromatic light or white light may be emitted from the light source. Alternatively, the light source includes a red light emitting element, a green light emitting element, and a blue light emitting element. By sequentially driving, light (red light, green light, and blue light) may be emitted from the light source, and by this, the light is emitted from a plurality of light emission positions arranged in a discrete manner. Alternatively, it is possible to obtain illumination light having different incident directions to the two-dimensional image forming apparatus.

  In the three-dimensional image display device according to the twelfth aspect or the thirteenth aspect of the present invention, an optical means for projecting a conjugate image formed by the conjugate image forming means may be provided. Optical means for projecting an image formed by the third lens may be provided behind the third lens.

In the three-dimensional image display device according to the second to third aspects or the fifth to sixth aspects of the present invention, m and m ′ are integers, and M is a positive integer. , M ′ and M are m ≦ m ′ and M = m′−m + 1. In addition, n and n ′ are integers, and N is a positive integer, but the relationship between n, n ′, and N is n ≦ n ′ and N = n′−n + 1. The number of M and N corresponding to the total number of diffraction orders is not limited,
0 ≦ M (= m′−m + 1) ≦ 21
Preferably, for example,
5 ≦ M (= m′−m + 1) ≦ 21
Also,
0 ≦ N (= n′−n + 1) ≦ 21
Preferably, for example,
5 ≦ N (= n′−n + 1) ≦ 21
Can be illustrated. The value of M and the value of N may be equal to or different from each other. The value of | m ′ | and the value of | m | may be equal to or different from each other. The value of n ′ | may be equal to or different from the value of | n |.

  Further, in the three-dimensional image display device according to the seventh aspect to the eighth aspect, in the optical device, the spatial frequency in the incident two-dimensional image corresponds to a plurality of diffraction orders (total M × N). Emitted along the diffraction angle, where M sets from the m-th order to the m′-th order along the X direction (where m and m ′ are integers, M is a positive integer), A total of M × N sets of diffracted light are generated along the Y direction from the nth to the n′th order (where n and n ′ are integers and N is a positive integer). The relationship between m, m ′, and M, and the relationship between n, n ′, and N can be as described above.

  Examples of the light source in the three-dimensional image display device according to the first to eighth aspects of the present invention including the various preferable configurations and forms described above include lasers, light emitting diodes (LEDs), and white light sources. it can. An illumination optical system for shaping the light emitted from the light source may be disposed between the light source and the light modulation means or the two-dimensional image forming apparatus.

  In a liquid crystal display device constituting a two-dimensional spatial light modulator or a two-dimensional image forming apparatus, for example, an area where a transparent first electrode and a transparent second electrode described below are overlapped and includes a liquid crystal cell is one pixel. (1 pixel). Then, the light transmittance of the light (illumination light) emitted from the light source is controlled by operating the liquid crystal cell as a kind of light shutter (light valve), that is, by controlling the light transmittance of each pixel. As a whole, a two-dimensional image can be obtained. By providing a rectangular opening in the overlapping region of the transparent first electrode and the transparent second electrode, light emitted from the light source (illumination light) passes through the opening, thereby causing Fraunhofer diffraction for each pixel. For example, M × N sets of diffracted light are generated.

  The liquid crystal display device includes, for example, a front panel provided with a transparent first electrode, a rear panel provided with a transparent second electrode, and a liquid crystal material disposed between the front panel and the rear panel. More specifically, the front panel includes, for example, a first substrate made of, for example, a glass substrate or a silicon substrate, and a transparent first electrode (also called a common electrode, for example, ITO provided on the inner surface of the first substrate. And a polarizing film provided on the outer surface of the first substrate. Furthermore, an alignment film is formed on the transparent first electrode. On the other hand, the rear panel more specifically includes, for example, a second substrate made of a glass substrate or a silicon substrate, a switching element formed on the inner surface of the second substrate, and conduction / non-conduction by the switching element. A transparent second electrode to be controlled (also called a pixel electrode, which is made of, for example, ITO) and a polarizing film provided on the outer surface of the second substrate. An alignment film is formed on the entire surface including the transparent second electrode. Various members and liquid crystal materials constituting these transmissive liquid crystal display devices can be formed of known members and materials. Examples of the switching element include a three-terminal element such as a MOS type FET and a thin film transistor (TFT) formed on a single crystal silicon semiconductor substrate, and a two-terminal element such as an MIM element, a varistor element, and a diode. Alternatively, a liquid crystal display device having a so-called matrix electrode configuration in which a plurality of scanning electrodes extend in a first direction and a plurality of data electrodes extend in a second direction can be provided. In the transmissive liquid crystal display device, light (illumination light) from the light source enters from the second substrate and is emitted from the first substrate. On the other hand, in a reflective liquid crystal display device, light (illumination light) from a light source is incident from a first substrate and is, for example, a second electrode (pixel electrode) formed on the inner surface of the second substrate. And is emitted from the first substrate again. The opening can be obtained, for example, by forming an opaque insulating material layer for light from the light source (illumination light) between the transparent second electrode and the alignment film, and forming the opening in the insulating material layer. . In addition, as the reflective liquid crystal display device, an LCoS (Liquid Crystal on Silicon) type can also be used.

  For example, when a liquid crystal display device composed of ferroelectric liquid crystal is used as the light modulation means (two-dimensional image forming apparatus), it is necessary to bring it closer to plus / minus 0 in terms of DC when a drive voltage is applied. That is, when a positive potential or a negative potential is applied for a certain period (where applied voltage × time is V × t), a voltage that cancels the same amount of V × t is It is necessary to apply for a period. In a ferroelectric liquid crystal, if such an operation is not performed, charges are accumulated in the ferroelectric liquid crystal, and a kind of baking occurs. Therefore, when it is necessary to continue a sequence in which a two-dimensional image is generated by a light modulation means or a two-dimensional image forming apparatus and then not generated, or when such a sequence can be adopted, It is preferable to use a liquid crystal display device composed of ferroelectric liquid crystal capable of high-speed operation.

  As a one-dimensional spatial light modulator (one-dimensional image forming apparatus), more specifically, an apparatus in which diffraction grating-light modulation elements (GLV: Grating Light Valve) are arranged one-dimensionally in an array ( Hereinafter, it may be referred to as a diffraction grating-light modulation device).

  In the three-dimensional image display device according to the first aspect to the eighth aspect and the twelfth aspect to the thirteenth aspect of the present invention, the conjugate image formed by the conjugate image forming means is projected. An optical means may be provided, or an optical means for projecting an image formed by the third lens or the fifth lens may be provided behind the third lens or the fifth lens. . Moreover, in the three-dimensional image display apparatus according to the ninth to tenth aspects of the present invention, the three-dimensional image display apparatus may include optical means for projecting an image formed by the image forming means, or Optical means for projecting an image formed by the third lens may be provided behind the third lens.

  In the three-dimensional image display device according to the first to thirteenth aspects of the present invention, when the number P × Q of pixels (pixels) of a two-dimensional image is represented by (P, Q), (P, Q) Specifically, values of VGA (640, 480), S-VGA (800, 600), XGA (1024, 768), APRC (1152, 900), S-XGA (1280, 1024), U- Image display resolutions such as XGA (1600, 1200), HD-TV (1920, 1080), Q-XGA (2048, 1536), (1920, 1035), (720, 480), (1280, 960), etc. However, the present invention is not limited to these values.

  In the three-dimensional image display apparatus according to the first to thirteenth aspects of the present invention, the light emitted from the optical system (specifically, the conjugate image forming means, the third lens, and the fifth Since a transflective mirror that changes the traveling direction of the light beam emitted from the lens, the imaging unit, or the Fourier transform image forming unit is provided, when observing an image reflected on the transflective mirror, three-dimensional The light source and the optical system constituting the image display device are not positioned in the observer's field of view, and the problem that the light source and the optical system overlap with the stereoscopic image and the stereoscopic image becomes difficult to see does not occur. Further, the viewpoint is easily guided to the reproduced stereoscopic image, and the recognition of the stereoscopic image is facilitated. Furthermore, it is possible to fuse the stereoscopic image and the background.

  On the other hand, in the three-dimensional image display device according to the first to thirteenth aspects of the present invention, the traveling direction of the light beam emitted from the optical system is changed, and the light beam emitted from the optical system is changed. Since it is equipped with a light beam control means for controlling the light collection state at the observation point, all the light beam groups (light beam groups having parallax information) necessary for displaying a stereoscopic image need not be spatially generated or scattered. Even if a group of rays necessary for displaying a stereoscopic image is spatially generated and scattered at a lower density, it is possible to obtain a stereoscopic image with light rays that are close to the same quality as real-world objects, and display a three-dimensional image. The burden on the image data processing system in the apparatus can be reduced.

  In the three-dimensional image display device according to the first aspect of the present invention to the third aspect of the present invention, a two-dimensional image is generated and generated by the light modulation means or the two-dimensional image forming apparatus. The spatial frequency in the two-dimensional image is emitted along diffraction angles corresponding to a plurality of diffraction orders generated from each pixel and the diffracted light generating means, and the spatial frequency is Fourier transformed by the Fourier transform image forming means or the first lens. A number of Fourier transform images corresponding to a plurality of diffraction orders are generated, and a Fourier transform image selection means or a spatial filter generates a desired number of diffraction orders among the Fourier transform images generated by the number corresponding to the plurality of diffraction orders. The corresponding Fourier transform image is selected in synchronization with the formation timing of the two-dimensional image, and the Fourier transform image is formed by the conjugate image forming means (second lens and third lens). A conjugate image of the Fourier transform image selected based on the image selection means or the spatial filter is formed, and the operation of finally reaching the observer is repeated sequentially and in time series, corresponding to a plurality of diffraction orders. As a result, the light beam can be generated and dispersed in a spatially high density and distributed in a plurality of directions. Based on the utilized light beam reproduction method, a three-dimensional image close to a real world object can be obtained without increasing the size of the entire image display apparatus.

  In the three-dimensional image display apparatus according to the fourth aspect to the sixth aspect of the present invention, a two-dimensional image is generated by the light modulation means (two-dimensional image forming apparatus), and A spatial frequency in the generated two-dimensional image is emitted along diffraction angles corresponding to a plurality of diffraction orders generated from each pixel or the like, and the spatial frequency is Fourier-transformed by an image limiting / generating unit (first lens). The number of Fourier transform images corresponding to the diffraction orders of the image is generated, and only a predetermined Fourier transform image is selected by the image limiting / generating means (scattering diffraction limiting aperture), and the image limiting / generating means (second The conjugate image of the two-dimensional image is generated by the lens. Then, the spatial frequency in the conjugate image of the two-dimensional image is emitted from the oversampling filter along diffraction angles corresponding to a plurality of diffraction orders generated from each aperture region, and Fourier transform image forming means (third lens) As a result, the spatial frequency is Fourier transformed to generate a number of Fourier transformed images corresponding to a plurality of diffraction orders generated from each aperture region. Next, a Fourier transform image corresponding to a desired diffraction order among the Fourier transform images generated by the Fourier transform image selection means (spatial filter) corresponding to a plurality of diffraction orders generated from each aperture region is a two-dimensional image. The conjugate image of the Fourier transform image selected based on the Fourier transform image selection means (spatial filter) is formed by the conjugate image formation means (second lens and third lens). Finally reach the observer. Such operations are sequentially repeated in time series, so that a group of rays corresponding to a plurality of diffraction orders generated from each aperture region in the oversampling filter can be spatially high in density and As a result of being able to generate and scatter in a state of being distributed in the direction, the entire image display device is enlarged based on a light beam reproduction method that efficiently utilizes the light diffraction phenomenon, which has not been conventionally used, due to such a light beam group. Therefore, it is possible to obtain an image (stereoscopic image) having a texture close to that of an object in the real world. Moreover, in the three-dimensional image display apparatus according to the fourth aspect to the sixth aspect of the present invention, an oversampling filter is arranged, that is, a light modulation means (two-dimensional image forming apparatus). Since the read image (conjugate image of the two-dimensional image) is newly spatially sampled independently, the size of the finally obtained image and the viewing angle can be controlled independently. Therefore, the scale (size) of the displayed image (stereoscopic image) can be increased while expanding the area of the observed image (stereoscopic image).

  In the three-dimensional image display apparatus according to the seventh aspect to the eighth aspect of the present invention, a two-dimensional image is generated by the two-dimensional image forming apparatus, and the spatial frequency in the generated two-dimensional image is refracted. Is emitted along diffraction angles corresponding to a plurality of diffraction orders by an optical device which is an assembly of optical elements composed of a lattice element of a mold, and a spatial frequency is Fourier transformed by a Fourier transform image forming means or a first lens. A number of Fourier transform images corresponding to a plurality of diffraction orders are generated, and a Fourier transform image selection means or a spatial filter generates a desired number of diffraction orders among the Fourier transform images generated by the number corresponding to the plurality of diffraction orders. Corresponding Fourier transform images are selected in synchronization with the formation timing of the two-dimensional image, and the conjugate image forming means (the second lens and the third lens) is used to select the Fourier transform image. D. A conjugate image of the Fourier transform image selected based on the transform image selection means or the spatial filter is formed, and the operation of finally reaching the observer is sequentially repeated in time series so that a plurality of diffraction orders are obtained. Can be generated and scattered in a spatially high density and distributed in multiple directions. As a result, the light group can efficiently eliminate the light diffraction phenomenon Based on the light ray reproducing method that has been used in practice, it is possible to obtain an image (stereoscopic image) having a texture close to that of an object in the real world without increasing the size of the entire image display device.

  The spatial frequency in the two-dimensional image generated by the two-dimensional image forming apparatus is changed along diffraction angles corresponding to a plurality of diffraction orders by an amplitude grating having a rectangular opening and generating Fraunhofer diffraction based on the rectangular opening. In some cases, it is difficult to produce an amplitude grating having a high aperture ratio. And since light utilization efficiency is dependent on the aperture ratio of an opening, there exists a possibility that it may become difficult to achieve high light utilization efficiency. On the other hand, when generating a Fourier transform image by Fourier transforming the spatial frequency in a two-dimensional image, the uniformity between the Fourier transform images corresponding to a plurality of diffraction orders (uniformity of light intensity between diffraction orders) is The smaller, the better. In the three-dimensional image display apparatus according to the seventh aspect to the eighth aspect of the present invention, an optical apparatus that is an aggregate of optical elements including refractive grating elements is employed instead of the amplitude grating. Therefore, not only can the optical element itself have a high aperture ratio and can improve the efficiency of light utilization, but also the light incident on the optical element is condensed at a substantially single point. Equivalent to the obtained one, high uniformity can be achieved between Fourier transform images corresponding to a plurality of diffraction orders. In addition, by optimizing the optical device, a large amount of energy can be distributed even for high-order diffraction. For example, if a phase grating in which a large number of concave portions are formed on a glass flat plate is employed, it is possible to increase the light utilization efficiency. However, in the case of pattern generation by phase modulation, an arbitrary pattern can be generated in a specific plane. However, in a system that generates an image by light rays in an arbitrary plane, a specific pattern is determined in an arbitrary plane. Is extremely difficult to generate. In the three-dimensional image display device according to the seventh aspect to the eighth aspect of the present invention, an optical device that is an assembly of optical elements composed of refractive grating elements is used instead of the phase grating. By doing so, such a problem in the phase grating can be solved.

  In the three-dimensional image display apparatus according to the ninth aspect to the eleventh aspect of the present invention, a two-dimensional image is generated by the light modulation means (two-dimensional image forming apparatus), and the generated two-dimensional image A spatial frequency is emitted along diffraction angles corresponding to a plurality of diffraction orders generated from each pixel or the like, and a spatial frequency is Fourier-transformed by an image limiting / generating unit (first lens) to correspond to a plurality of diffraction orders. Of the two-dimensional image is selected by the image limiting / generating means (scattering diffraction limiting aperture) and the image limiting / generating means (second lens). A conjugate image is generated. Then, the spatial frequency in the conjugate image of the two-dimensional image is emitted from the light beam traveling direction changing means at a desired angle with respect to the z ′ axis that is the optical axis. Further, a conjugate image of the Fourier transform image emitted from the light beam traveling direction changing unit is formed on the imaging plane by the imaging unit (third lens), and finally reaches the observer. And, such operations are sequentially repeated in time series so that the light beam emitted from the light beam traveling direction changing means is spatially high in density and distributed in a plurality of directions. As a result of being able to generate and scatter, the entire image display device is based on the light ray reproduction method that efficiently controls the direction component of light rays for constructing an image (stereoscopic image), which has not been conventionally used, with such a light ray group. An image (stereoscopic image) with a texture close to that of a real world object can be obtained without increasing the size. In addition, in the three-dimensional image display apparatus according to the ninth to eleventh aspects of the present invention, the loss of light quantity in the light beam traveling direction changing means is so small that it can be ignored. Therefore, a clear and blur-free image (stereoscopic image) can be observed without reducing the contrast of the image to be displayed.

In the three-dimensional image display apparatus according to the twelfth to thirteenth aspects of the present invention, the light modulation means (2) is based on light (illumination light) emitted sequentially from different light emission positions of the light source and having different incident directions. A two-dimensional image is generated by a two-dimensional image forming apparatus), and a spatial frequency in the generated two-dimensional image is emitted along diffraction angles corresponding to a plurality of diffraction orders generated from each pixel or the like to form a Fourier transform image The spatial frequency is Fourier-transformed by the means (first lens) to generate a number of Fourier-transformed images (diffracted lights) corresponding to a plurality of diffraction orders, which are formed and finally reach the observer. The image reaching the observer includes a component in the incident direction of light (illumination light) to the light modulation means (two-dimensional image forming apparatus). Then, by repeating such operations sequentially in time series, a group of light beams (for example, LEP _Total light beams) emitted from the Fourier transform image forming means (first lens) are spatially converted. As a result of being able to generate and scatter in a state of high density and distributed in multiple directions, the light ray direction component for constructing an image (stereoscopic image), which has never existed in the past, is efficiently obtained by such a light ray group. Based on the controlled light beam reproduction method, it is possible to obtain an image (stereoscopic image) having a texture close to an object in the real world without increasing the size of the entire image display apparatus. Moreover, in the image display devices according to the twelfth to thirteenth aspects of the present invention, for example, if an image (stereoscopic image) is formed based on the 0th-order diffracted light, a bright, clear, high-quality image (stereoscopic) is formed. Image).

1A, 1B, and 1C schematically illustrate the arrangement of a light source, an optical system, and a transflective mirror in the three-dimensional image display apparatus according to the first to thirteenth aspects of the present invention. FIG. 2A is a diagram schematically showing the arrangement of a light source, an optical system, and a transflective mirror in the three-dimensional image display device according to the first to thirteenth aspects of the present invention. 2A, 2B, and 2C schematically illustrate the arrangement of the light source, the optical system, and the light beam control means in the three-dimensional image display device according to the first to thirteenth aspects of the present invention. FIG. FIG. 3 is a conceptual diagram in the yz plane of the three-dimensional image display apparatus according to the first embodiment. FIG. 4 is a conceptual diagram of the three-dimensional image display device according to the first embodiment when viewed from an oblique direction. FIG. 5 is a conceptual diagram of the three-dimensional image display device according to the first embodiment when viewed from an oblique direction. FIG. 6 is a schematic front view of an example of Fourier transform image selection means (spatial filter). FIG. 7 is a diagram schematically illustrating a state in which diffracted light having a plurality of diffraction orders is generated by the light modulation unit (two-dimensional image forming apparatus) according to the first embodiment. FIG. 8 is a schematic diagram illustrating a condensing state in the Fourier transform image forming unit (first lens L ₁ ) and an image forming state in the Fourier transform image selecting unit (spatial filter) in the three-dimensional image display apparatus according to the first embodiment. FIG. (A) and (B) of FIG. 9 respectively show the state of the lowest spatial frequency and the state of the highest spatial frequency in the two-dimensional image generated by the light modulator (two-dimensional image forming apparatus). 1 is a schematic front view of a two-dimensional image forming apparatus. (A) and (B) of FIG. 10 respectively show the light of the Fourier transform image in the state where the spatial frequency is the lowest and the highest in the two-dimensional image generated by the light modulation means (two-dimensional image forming apparatus). It is a figure which shows typically the frequency characteristic of an intensity | strength. 11A is a schematic diagram showing the distribution of the Fourier transform image on the xy plane of the Fourier transform image selection means (spatial filter), and FIGS. 11B and 11C are diagrams of FIG. It is a figure which shows the light intensity distribution of the Fourier-transform image on the x-axis of A). FIG. 12 is a conceptual diagram of the three-dimensional image display apparatus according to the third embodiment. FIG. 13 is a conceptual diagram of a part of the light modulation unit (two-dimensional image forming apparatus) in the three-dimensional image display apparatus according to the third embodiment. FIG. 14 is a conceptual diagram on the yz plane of the three-dimensional image display apparatus according to the fourth embodiment. FIG. 15 is a conceptual diagram when the three-dimensional image display apparatus according to the fourth embodiment is viewed from an oblique direction. FIG. 16 is a diagram schematically illustrating an arrangement state of components of the three-dimensional image display device according to the fourth embodiment. FIG. 17 is a schematic diagram illustrating a condensing state in the Fourier transform image forming unit (third lens L ₃ ) and an image forming state in the Fourier transform image selecting unit (spatial filter) in the three-dimensional image display apparatus according to the fourth embodiment. FIG. FIG. 18 is a conceptual diagram of the three-dimensional image display apparatus according to the fifth embodiment. FIG. 19 is a conceptual diagram on the yz plane of the three-dimensional image display apparatus according to the sixth embodiment. FIG. 20 is a conceptual diagram for explaining the operation and action of the optical device in the three-dimensional image display device according to the sixth embodiment. FIG. 21 is a conceptual diagram when the three-dimensional image display apparatus according to the sixth embodiment is viewed from an oblique direction. FIG. 22 is a diagram schematically illustrating an arrangement state of components of the three-dimensional image display device according to the sixth embodiment. FIG. 23 is a diagram schematically illustrating a state in which diffracted light having a plurality of diffraction orders is generated by the two-dimensional image forming apparatus in the sixth embodiment. FIG. 24 is a conceptual diagram of the three-dimensional image display apparatus according to the seventh embodiment. FIG. 25 is a conceptual diagram on the yz plane of the three-dimensional image display apparatus according to the eighth embodiment. FIG. 26 is a conceptual diagram when the three-dimensional image display device according to the eighth embodiment is viewed from an oblique direction. FIG. 27 is a diagram schematically illustrating an arrangement state of components of the three-dimensional image display device according to the eighth embodiment. FIG. 28 is a conceptual diagram of the three-dimensional image display apparatus according to the ninth embodiment. FIG. 29 is a conceptual diagram on the yz plane of the three-dimensional image display apparatus according to the tenth embodiment. FIG. 30 is a diagram schematically illustrating an arrangement state of components of the three-dimensional image display device according to the tenth embodiment. FIG. 31 is an enlarged conceptual diagram of a part of the three-dimensional image display apparatus according to the tenth embodiment. 32A and 32B schematically show a state in which diffracted light of a plurality of diffraction orders is generated by the light modulation means (two-dimensional image forming apparatus) in the three-dimensional image display apparatus of the tenth embodiment. FIG. FIG. 33 is a schematic front view of a light source in the three-dimensional image display apparatus according to the tenth embodiment. FIG. 34 is a schematic front view of a spatial filter in the three-dimensional image display apparatus according to the tenth embodiment. FIG. 35 is a conceptual diagram of the three-dimensional image display device according to the eleventh embodiment on the yz plane. FIG. 36 is an enlarged conceptual view of a part of the three-dimensional image display apparatus according to Example 11 shown in FIG. 35 (however, a certain light emitting element is in a light emitting state). FIG. 37 is an enlarged conceptual view of a part of the three-dimensional image display apparatus according to Example 11 shown in FIG. 35 (however, another light emitting element is in a light emitting state). FIG. 38 is a conceptual diagram in which a part of the three-dimensional image display apparatus according to Example 11 shown in FIG. 35 is enlarged (however, another light emitting element is in a light emitting state). FIG. 39 is a conceptual diagram of a part of the three-dimensional image display apparatus according to the twelfth embodiment on the yz plane. FIG. 40 is a diagram showing the formation timing of a two-dimensional image in the light modulation means (two-dimensional image forming apparatus) and the opening / closing timing of the opening of the Fourier transform image selection means (spatial filter). The two-dimensional image formation timing in the means (two-dimensional image forming apparatus) is shown, and the opening and closing timing of the opening of the Fourier transform image selection means (spatial filter) is shown in the middle and lower stages. FIG. 41 is a diagram schematically showing the concept of spatial filtering by Fourier transform image selection means (spatial filter) in time series. FIG. 42 is a diagram schematically showing an image obtained as a result of the spatial filtering shown in FIG. FIG. 43 is a diagram schematically showing at which position an image is formed on the imaging plane by performing position control of the light beam traveling direction changing means. FIG. 44 is a diagram schematically showing the arrangement of the lower electrode, the fixed electrode, and the movable electrode constituting the diffraction grating-light modulation element. 45A is a schematic cross-sectional view of the fixed electrode and the like along the arrow BB in FIG. 44, and a schematic cross-sectional view of the movable electrode and the like along the arrow AA in FIG. However, the diffraction grating-light modulation element is not in operation), and FIG. 45B is a schematic cross-sectional view of the movable electrode and the like along the arrow AA in FIG. However, FIG. 45C is a schematic cross-sectional view of the fixed electrode, the movable electrode, and the like along the arrow CC in FIG. 44. . (A), (B), and (C) in FIG. 46 are a first configuration example, a second configuration example, and a light source and illumination optical system in the three-dimensional image display devices according to the first to ninth embodiments, respectively. It is a schematic diagram which shows a 3rd structural example. 47A and 47B are schematic diagrams illustrating a fourth configuration example and a fifth configuration example of the light source and the illumination optical system in the three-dimensional image display apparatuses according to the first to ninth embodiments, respectively. is there. 48A and 48B are conceptual diagrams on a yz plane of a part of a modification of the three-dimensional image display apparatus according to the first embodiment. FIG. 49 is a conceptual diagram on a yz plane of a part of another modification of the modification of the three-dimensional image display device according to the first embodiment. 50A and 50B are diagrams schematically showing a state in which light beams necessary for displaying a stereoscopic image are spatially scattered. FIG. 51 is a configuration diagram illustrating a multi-unit type three-dimensional image display device in which a plurality of three-dimensional image display devices according to the first embodiment are combined. FIG. 52 is a diagram illustrating a configuration example of a conventional three-dimensional image display apparatus.

  Hereinafter, the present invention will be described based on examples with reference to the drawings.

  Example 1 relates to a three-dimensional image display apparatus according to the first A aspect and the second A aspect of the present invention. FIG. 1A, FIG. 3, FIG. 4 and FIG. 5 are conceptual diagrams of a three-dimensional image display apparatus of Example 1 for monochromatic display. In FIG. 3, the optical axis is the z axis, the orthogonal coordinates in the plane orthogonal to the z axis are the x axis and the y axis, the direction parallel to the x axis is the X direction, and the direction parallel to the y axis is Y. The direction. The X direction is, for example, the horizontal direction in the 3D image display device, and the Y direction is, for example, the vertical direction in the 3D image display device. Here, FIG. 3 is a conceptual diagram of the three-dimensional image display apparatus of Example 1 in the yz plane. The conceptual diagram of the three-dimensional image display apparatus of the first embodiment in the xz plane is substantially the same as FIG. FIG. 4 is a conceptual diagram of the three-dimensional image display apparatus according to the first embodiment when viewed from an oblique direction. FIG. 5 schematically illustrates the arrangement state of the components of the three-dimensional image display apparatus according to the first embodiment. FIG. The z-axis (corresponding to the optical axis) passes through the center of each component constituting the three-dimensional image display device of each embodiment, and is orthogonal to each component constituting the three-dimensional image display device.

  In the display of stereoscopic images using the conventional ray reconstruction method, rays that are emitted at various angles are provided in advance in order to emit a plurality of rays with the virtual object surface existing at an arbitrary position as a virtual origin. It is necessary to have a device that can do this. That is, for example, in the apparatus shown in FIG. 52, a large number (for example, M × N) of projector units 301 must be arranged in parallel in the horizontal direction and the vertical direction.

  On the other hand, the three-dimensional image display apparatus 1A according to the first embodiment is a conventional three-dimensional image display apparatus having the components shown in FIG. 1A, FIG. 3, FIG. 4 and FIG. Compared to the above, it is possible to generate and form a large number of light beams with high spatial density. The three-dimensional image display device 1A according to the first embodiment is a single three-dimensional image display device, in which a large number (M × N) of projector units 301 shown in FIG. 52 are arranged in parallel in the horizontal direction and the vertical direction. It has a function equivalent to the device. For example, when the multi-unit method is adopted, the three-dimensional image display device 1A of the first embodiment may be provided as many as the number of divided three-dimensional images as shown in FIG. In FIG. 51, an apparatus provided with 4 × 4 = 16 three-dimensional image display apparatus 1A of the first embodiment is illustrated.

Describing along the components of the three-dimensional image display device according to the aspect 1A of the present invention, the three-dimensional image display device 1A of Example 1 is a three-dimensional image display device including a light source 10 and an optical system. 1A. And this optical system
(A) A plurality of pixels 31 are provided, light from a light source is modulated by each pixel 31 to generate a two-dimensional image, and a spatial frequency in the generated two-dimensional image is converted into a plurality of diffractions generated from each pixel 31. Light modulating means 30 that emits along a diffraction angle corresponding to the order (total M × N);
(B) Fourier transform image forming means for generating a Fourier transform image having a number corresponding to the plurality of diffraction orders (total M × N) by subjecting the spatial frequency in the two-dimensional image emitted from the light modulation means 30 to Fourier transform. 40,
(C) Fourier transform image selection means 50 for selecting a Fourier transform image corresponding to a desired diffraction order among the Fourier transform images generated by the number corresponding to the plurality of diffraction orders, and
(D) conjugate image forming means 60 for forming a conjugate image of the Fourier transform image selected by the Fourier transform image selection means;
It has.

Further, the conjugate image forming unit 60 performs inverse Fourier transform on the Fourier transform image selected by the Fourier transform image selection unit 50 to form a real image of the two-dimensional image generated by the light modulation unit 30. Conversion means (specifically, a second lens L ₂ described later) is provided. Further, the Fourier transform image forming means 40 comprises a lens, the light modulation means 30 is disposed on the front focal plane of the lens, and the Fourier transform image selection means 50 is disposed on the rear focal plane of the lens. The Fourier transform image selection means 50 has a number of openings 51 that can be opened and closed corresponding to a plurality of diffraction orders.

  Here, the spatial frequency in the two-dimensional image corresponds to image information using the spatial frequency of the pixel structure as the carrier frequency.

Further, the description will be made along the components of the three-dimensional image display device according to the 2A aspect of the present invention. It is a display device. And this optical system
(A) P × Q apertures (where P and Q are arbitrary positive integers) arranged in a two-dimensional matrix along the X direction and the Y direction, and the light from the light source 10 A two-dimensional image is generated by controlling the passage for each aperture, and M sets from the m-th order to the m′-th order along the X direction are provided for each aperture based on the two-dimensional image (however, m and m ′ are integers, M is a positive integer), and N sets from the n-th order to the n′-th order along the Y direction (where n and n ′ are integers, N is a positive number) A two-dimensional image forming apparatus 30 that generates a total of M × N sets of diffracted light,
(B) a first lens (more specifically, a convex lens in the first embodiment) L ₁ in which the two-dimensional image forming apparatus 30 is disposed on the front focal plane thereof;
(C) M × N open / close controllable openings 51 are arranged on the rear focal plane of the first lens L ₁ and M in the X direction and N in the Y direction. A spatial filter SF,
(D) a second lens (more specifically, a convex lens in Example 1) L ₂ in which a spatial filter SF is disposed on its front focal plane, and
(E) a third lens (more specifically, a convex lens in the first embodiment) L ₃ in which the front focal point is located at the rear focal point of the second lens L ₂ ;
It has.

Then, the three-dimensional image display device 1A of the first embodiment, further, the traveling direction of a light ray emitted (specifically, light beams emitted from the conjugate image formation means 60 or the third lens L ₃₎ from the optical system Is provided with a transflective mirror 90 that changes (changes). The transflective mirror 90 is made of, for example, a dielectric multilayer film such as a partially transmissive (reflective) mirror. Incidentally, as shown in the conceptual diagram of FIG. There are no light sources and optics on the extension of the modified ray path. That is, the light source and the optical system do not exist on the extension of “path-2”. In order to achieve such a configuration, the arrangement of the transflective mirrors may be optimized. Alternatively, a shielding member 91 made of, for example, an opaque plate or sheet may be disposed in the extension of the light path, as shown in the conceptual diagrams of FIGS. 1B and 1C. In addition, you may draw the picture used as the kind of background of a stereo image on the shielding member 91. FIG. In the example shown in FIG. 1B and FIG. 1C, the image of the light source does not exist on the extension of “path-2”. In other words, the image of the light source is concealed from the observer by the shielding member 91. In the example shown in FIG. 1C, specifically, the shielding member 91 is at the same level (or substantially the same level) as the upper surface of the three-dimensional image display device 1A. It is arranged in parallel (or substantially parallel) with the upper surface. The arrangement state of the semi-transmissive mirror 90 is different between FIG. 1B and FIG. 1C, and the example shown in FIG. The light beam reflected by is directed upward from the example shown in FIG. As shown in FIG. 1A, FIG. 1B, or FIG. 1C, the transflective mirror 90 may be a flat mirror with a flat reflecting surface, or FIG. As shown in (A), the transflective mirror 92 may be a concave mirror having a concave reflecting surface. The semi-transmissive mirrors 90 and 92 and the shielding member 91 described above can also be applied to Examples 3 to 12 to be described later.

Here, in Example 1, Example 2, Example 3 and Example 12 described later, P = 1024, Q = 768, m = -4, m '= 4, M = m'- m + 1 = 9, n = -4, n '= 4, and N = n'-n + 1 = 9. However, it is not limited to these values. When the constituent elements of the three-dimensional image display device according to the first aspect of the present invention are compared with the constituent elements of the three-dimensional image display device according to the second or third aspect of the present invention, the light modulation means 30 is corresponding to the two-dimensional image forming apparatus 30, the Fourier transform image forming means 40 corresponds to the first lens L _1, the Fourier transform image selection means 50 corresponds to the spatial filter SF, the inverse Fourier transform unit and the second lens Corresponding to L ₁ , the conjugate image forming means 60 corresponds to the second lens L ₂ and the third lens L ₃ . Therefore, for the sake of convenience, the following description will be made based on the terms two-dimensional image forming apparatus 30, first lens L ₁ , spatial filter SF, second lens L ₁ , and third lens L ₃ .

  An illumination optical system 20 for shaping the light emitted from the light source 10 is disposed between the light source 10 and the two-dimensional image forming apparatus 30. The two-dimensional image forming apparatus 30 is illuminated with light (illumination light) emitted from the light source 10 and passed through the illumination optical system 20. As illumination light, for example, light obtained by shaping light from the light source 10 with high spatial coherence into parallel light by the illumination optical system 20 is used. The characteristics of the illumination light and a specific configuration example for obtaining the illumination light will be described later.

  The two-dimensional image forming apparatus 30 includes a two-dimensional spatial light modulator having a plurality of pixels 31 arranged two-dimensionally, and each pixel 31 has an opening. Specifically, the two-dimensional image forming apparatus 30 or the two-dimensional spatial light modulator is two-dimensionally arranged, that is, P × Q arranged in a two-dimensional matrix along the X direction and the Y direction. It consists of a transmissive liquid crystal display device having a number of pixels 31, and each pixel 31 is provided with an opening.

  One pixel 31 is an overlapping region of the transparent first electrode and the transparent second electrode, and includes a region including a liquid crystal cell. Then, by operating the liquid crystal cell as a kind of light shutter (light valve), that is, by controlling the light transmittance of each pixel 31, the light transmittance of the light emitted from the light source 10 is controlled, As a whole, a two-dimensional image can be obtained. In the overlapping region of the transparent first electrode and the transparent second electrode, a rectangular opening is provided, and when light emitted from the light source 10 passes through the opening, Fraunhofer diffraction occurs. XN sets = 81 sets of diffracted light are generated. In other words, since the number of pixels 31 is P × Q, it can be considered that a total of (P × Q × M × N) diffracted lights are generated. In the two-dimensional image forming apparatus 30, the spatial frequency in the two-dimensional image is emitted from the two-dimensional image forming apparatus 30 along diffraction angles corresponding to a plurality of diffraction orders (total M × N) generated from each pixel 31. . The diffraction angle varies depending on the spatial frequency in the two-dimensional image.

A two-dimensional image forming apparatus 30 is arranged on the front focal plane (focal plane on the light source side) of the first lens L ₁ having a focal length f _1, and the rear focal plane (observation) of the first lens L _1. The spatial filter SF is disposed on the focal plane on the person side. The first lens L ₁ generates M × N = 81 Fourier transform images that are numbers corresponding to a plurality of diffraction orders, and these Fourier transform images are formed on the spatial filter SF. In FIG. 4, for the sake of convenience, 64 Fourier transform images are shown as dots.

Specifically, the spatial filter SF is a spatial filter capable of temporal opening and closing control for spatially and temporally filtering the Fourier transform image. More specifically, the spatial filter SF has a number of openings 51 that can be controlled to open and close (specifically, M × N = 81) corresponding to a plurality of diffraction orders. In the spatial filter SF, one Fourier corresponding to a desired diffraction order is obtained by opening one desired opening 51 in synchronization with the generation timing of a two-dimensional image by the two-dimensional image forming apparatus 30. Select the conversion image. More specifically, the spatial filter SF is, for example, a transmissive liquid crystal display device or a reflective liquid crystal display device using a ferroelectric liquid crystal having M × N pixels, or a movable mirror is a two-dimensional matrix. It can be composed of a two-dimensional type MEMS including devices arranged in a shape. FIG. 6 shows a schematic front view of the spatial filter SF formed of a liquid crystal display device. In FIG. 6, numerals (m ₀ , n ₀ ) indicate the numbers of the openings 51 and the diffraction orders. That is, for example, a Fourier transform image having a diffraction order of m ₀ = 3 and n ₀ = 2 is incident on the (3, 2) -th opening 51.

As described above, specifically, the conjugate image forming unit 60 includes the second lens L ₂ and the third lens L ₃ . The second lens L ₂ having the focal length f ₂ performs the inverse Fourier transform on the Fourier transform image filtered by the spatial filter SF, thereby realizing the real image RI of the two-dimensional image generated by the two-dimensional image forming apparatus 30. Form. The third lens L ₃ having a focal length f ₃ forms a conjugate image CI of the Fourier transform image filtered by the spatial filter SF.

The second lens L ₂ is arranged on the front focal plane so that the spatial filter SF is positioned, and a real image RI of the two-dimensional image generated by the two-dimensional image forming apparatus 30 is formed on the rear focal plane. Are arranged to be. The magnification of the real image RI obtained here with respect to the two-dimensional image forming apparatus 30 can be changed by arbitrarily selecting the focal length f ₂ of the second lens L ₂ .

On the other hand, the third lens L ₃ is arranged such that its front focal plane coincides with the rear focal plane of the second lens L ₂ , and a conjugate image CI of the Fourier transform image is formed on the rear focal plane. Are arranged as follows. Here, since the rear focal plane of the third lens L ₃ is a conjugate plane of the spatial filter SF, it is generated by the two-dimensional image forming apparatus 30 from a portion corresponding to one opening 51 on the spatial filter SF. This is equivalent to the output of the two-dimensional image. The amount of light finally generated and output is an amount obtained by multiplying the number of pixels (P × Q) by a plurality of diffraction orders (specifically, M × N) transmitted through the optical system. Can be defined. Further, although the back focal plane of the third lens L ₃ conjugate image CI of the Fourier transform image is formed, in the back focal plane of the third lens L _3, orderly group of light beams are two-dimensionally It can be regarded as being placed. That is, as a whole, the projector unit 301 shown in FIG. 52 is arranged for a plurality of diffraction orders (specifically, M × N) on the rear focal plane of the third lens L ₃ . Is equivalent to

As schematically shown in FIGS. 4 and 7, nine pixels from the fourth order to the fourth order along the X direction are arranged along the Y direction by one pixel 31 in the two-dimensional image forming apparatus 30. Nine sets from the −4th order to the + 4′th order, a total of M × N sets = 81 sets of diffracted light are generated. In FIG. 7, only the diffracted light of the 0th order light (n ₀ = 0), ± 1st order light (n ₀ = ± 1), and ± 2nd order light (n ₀ = ± 2) is shown as a representative. As shown, higher-order diffracted light is actually generated, and a stereoscopic image is finally formed based on these diffracted light. Here, all image information (information of all pixels) of the two-dimensional image generated by the two-dimensional image forming apparatus 30 is collected in the diffracted light (light beam) of each diffraction order. A plurality of light beam groups (9 × 9 = 81 light beam groups) generated by diffraction from the same pixel on the two-dimensional image forming apparatus 30 all have the same image information at the same time. In other words, in the two-dimensional image forming apparatus 30 including a transmissive liquid crystal display device having P × Q pixels 31, the light from the light source 10 is modulated by each pixel 31 to generate a two-dimensional image. In addition, the spatial frequency in the generated two-dimensional image is emitted along diffraction angles corresponding to a plurality of diffraction orders (total M × N) generated from each pixel 31. That is, M × N types of copies of the two-dimensional image are emitted from the two-dimensional image forming apparatus 30 along diffraction angles corresponding to a plurality of diffraction orders (total M × N).

Then, the spatial frequency in the two-dimensional image in which all the image information of the two-dimensional image generated by the two-dimensional image forming apparatus 30 is aggregated is Fourier-transformed by the first lens L ₁ , and a plurality of diffraction orders (total M × The number of Fourier transform images corresponding to N) is generated, and the Fourier transform images are formed on the spatial filter SF. In the first lens L ₁ , a Fourier transform image having a spatial frequency in a two-dimensional image emitted along diffraction angles corresponding to a plurality of diffraction orders is generated. Obtainable.

Here, the wavelength of the light (illumination light) emitted from the light source 10 is λ (mm), the spatial frequency in the two-dimensional image generated by the two-dimensional image forming apparatus 30 is ν (lp / mm), and the first lens Assuming that the focal length of L ₁ is f ₁ (mm), light having a spatial frequency ν (Fourier transform image) at a distance Y ₁ (mm) from the optical axis on the rear focal plane of the first lens L _1. ) Appears.

Y ₁ = f ₁ · λ · ν (A)

FIG. 8 schematically shows a condensing state of the first lens L ₁ . In FIG. 8, “Y ₀ ” indicates the length in the y-axis direction of the two-dimensional image generated by the two-dimensional image forming apparatus 30, and “Y ₁ ” is generated by the two-dimensional image forming apparatus 30. The interval in the y-axis direction of the Fourier transform image on the spatial filter SF based on the two-dimensional image is shown. Further, the 0th-order diffracted light is indicated by a solid line, the first-order diffracted light is indicated by a dotted line, and the second-order diffracted light is indicated by a one-dot chain line. In other words, the diffracted light of each diffraction order, in other words, the Fourier transform image generated by the number corresponding to the diffraction order is condensed by the first lens L ₁ on different openings 51 on the spatial filter SF (FIG. (See also 4). As described above, the number of the openings 51 is M × N = 81. The converging angle (divergence angle after being emitted from the spatial filter SF) θ to the spatial filter SF is the same in the P × Q pixels 31 in the Fourier transform image (or diffracted light) having the same diffraction order. It is. On the spatial filter SF, an interval between Fourier transform images of adjacent diffraction orders can be obtained from the equation (A). By arbitrarily selecting the focal length f ₁ of the first lens L ₁ from the formula (A), it is possible to change the position of the Fourier transform image (image position on the spatial filter SF).

In the first lens L _1, in order to transmit the spatial frequency in the two-dimensional image emitted along the diffraction angles corresponding to a plurality of diffraction orders, the first lens L ₁ in accordance with the diffraction order to use It is necessary to select an aperture ratio NA, and the aperture ratios of all lenses after the first lens L ₁ are required to be equal to or higher than the aperture ratio NA of the first lens L ₁ regardless of the focal length. .

Size of the opening 51 may be the same value as the value of Y ₁ in the formula (A). As an example, the wavelength λ of the illumination light 532 nm, and the focal length f ₁ of the first lens L ₁ 50 mm, the size of one pixel 31 of the two-dimensional image forming apparatus 30 is for approximately 13Myuemu～14myuemu, Y ₁ Value Is about 2 mm. This means that a Fourier transform image corresponding to each diffraction order can be obtained at a high density of about 2 mm on the spatial filter SF. In other words, 9 × 9 = 81 Fourier transform images can be obtained on the spatial filter SF at intervals of about 2 mm in both the X direction and the Y direction.

  Here, since the spatial frequency ν in the two-dimensional image generated by the two-dimensional image forming apparatus 30 is generated by the two-dimensional image forming apparatus 30 including the P × Q pixels 31, the two-dimensional image is generated. At most, the frequency has a period composed of two consecutive pixels 31 constituting the two-dimensional image forming apparatus 30.

FIG. 9A shows a schematic front view of the two-dimensional image forming apparatus 30 in the state where the spatial frequency in the two-dimensional image generated by the two-dimensional image forming apparatus 30 is the lowest. Here, the state with the lowest spatial frequency is a case where all pixels are displayed in black or white, and the spatial frequency in the two-dimensional image in this case has only a plane wave component (DC component). . FIG. 9A shows a case where white display is performed. In this case, the frequency characteristic of the light intensity of the Fourier transform image formed by the first lens L ₁ is schematically shown in FIG. 10A. The peak of the light intensity of the Fourier transform image has a frequency ν _1. Appears at intervals of.

On the other hand, FIG. 9B shows a schematic front view of the two-dimensional image forming apparatus 30 in the state where the spatial frequency in the two-dimensional image generated by the two-dimensional image forming apparatus 30 is the highest. Here, the state with the highest spatial frequency is a case where all the pixels alternately display black display and white display. In this case, the frequency characteristic of the light intensity of the Fourier transform image formed by the first lens L ₁ is schematically shown in FIG. 10B. The peak of the light intensity of the Fourier transform image has a frequency ν _2. (= ν _1/2) appears at intervals. FIG. 11A schematically shows the distribution of the Fourier transform image on the spatial filter SF (on the xy plane), and FIGS. 11B and 11C show the x-axis of FIG. The light intensity distribution of the Fourier transform image on (it represents with a dotted line) is shown typically. 11B shows the lowest spatial frequency component (plane wave component), and FIG. 11C shows the highest spatial frequency component.

  9A and 9B, the spatial frequency is the lowest, the spatial frequency is the highest, and the frequency of the light intensity of the Fourier transform image shown in FIGS. 10A and 10B. The discussion on the characteristics, the distribution of the Fourier transform image on the spatial filter SF shown in FIGS. 11A, 11B, and 11C, and the light intensity distribution of the Fourier transform image also applies to other embodiments described later. can do.

  The planar shape of the opening 51 in the spatial filter SF may be determined based on the shape of the Fourier transform image. Furthermore, an opening 51 may be provided for each diffraction order so that the peak position of the plane wave component of the Fourier transform image is centered. As a result, the peak of the light intensity of the Fourier transform image is located at the center position 52 of each opening 51. That is, an opening that allows all the highest positive and negative spatial frequencies in the two-dimensional image to pass through the periodic pattern of the Fourier transform image when the spatial frequency in the two-dimensional image is the lowest spatial frequency component (plane wave component). 51 may be used.

By the way, the state with the highest spatial frequency is a case where all pixels alternately display black display and white display, as shown in FIG. 9B. The relationship between the spatial frequency of the pixel structure in the two-dimensional image forming apparatus 30 and the spatial frequency in the two-dimensional image is as follows. That is, assuming that the aperture occupies all of the pixels, the highest spatial frequency in the two-dimensional image is (1/2) of the spatial frequency of the pixel structure. Also, if the aperture occupies a certain percentage of pixels (less than 1), the highest spatial frequency in the two-dimensional image is below (1/2) the spatial frequency of the pixel structure. Therefore, all the spatial frequencies in the two-dimensional image appear up to the half of the periodic pattern interval due to the pixel structure appearing in the spatial filter SF. For this reason, all the openings 51 can be arranged without spatially interfering with each other. That is, for example, the (3,2) th aperture 51, while the Fourier transform image having a diffraction order of _{m 0 = 3, n 0 =} 2 enters, the _{m 0 = 3, n 0 =} 2 The Fourier transform image having the diffraction order does not enter the other openings 51. As a result, the space in the two-dimensional image generated by the two-dimensional image forming apparatus 30 in the Fourier transform image located in one opening 51 on the spatial filter SF having the independent opening 51 for each Fourier transform image. While the frequency exists, the spatial frequency in the two-dimensional image generated by the two-dimensional image forming apparatus 30 is not lost due to the spatial restriction of the opening 51. Note that the spatial frequency of the pixel structure can be regarded as the carrier frequency, and the spatial frequency in the two-dimensional image corresponds to image information using the spatial frequency of the pixel structure as the carrier frequency.

  In the spatial filter SF, the opening / closing control of the opening 51 is performed in order to control the passage / non-passage of the M × N Fourier transform images. If the spatial filter SF is composed of, for example, a liquid crystal display device, the opening / closing control of the opening 51 can be performed by operating the liquid crystal cell as a kind of light shutter (light valve).

If the brightness of the obtained image is different depending on the diffraction order, a neutral density filter that attenuates a bright image with respect to the darkest image is used as the third lens L ₃ (or most What is necessary is just to arrange | position to the back side focal plane of the lens located behind. The same applies to other embodiments described later.

  Moreover, the opening / closing control of the openings 51 provided in the spatial filter SF may not be performed for all the openings 51. That is, for example, the opening / closing control of every other opening 51 may be performed, or the opening / closing control of only the opening 51 located at a desired position may be performed. The same applies to other embodiments described later.

  The timing of opening / closing control of the opening 51 in the spatial filter SF will be described later. A configuration example of the light source and the illumination optical system will also be described later.

  In the three-dimensional image display apparatus according to the first embodiment or the second to twelfth embodiments described later, the operation of the light modulation means and the two-dimensional image forming apparatus is controlled by a personal computer (not shown).

In the three-dimensional image display apparatus according to the first embodiment, the traveling direction of the light beam emitted from the optical system (specifically, the light beam emitted from the conjugate image forming unit 60 or the third lens L ₃ ) is changed. Since the semi-transmissive mirrors 90 and 92 are provided, when observing an image reflected on the semi-transmissive mirrors 90 and 92, the light source and the optical system constituting the three-dimensional image display device are positioned within the field of view of the observer. This eliminates the problem that the light source and the optical system overlap with the stereoscopic image and the stereoscopic image becomes difficult to see.

  Further, according to the three-dimensional image display device 1A of the first embodiment, since the light beam reproduction method is used, it is possible to provide a stereoscopic image that satisfies visual functions such as focus adjustment, convergence, and motion parallax. . Furthermore, according to the three-dimensional image display apparatus 1A of the first embodiment, since high-order diffracted light is efficiently used, one image output device (two-dimensional image formation) is compared with a conventional image output method. Light rays (a kind of copy of the two-dimensional image) that can be controlled by the device 30) can be obtained for a plurality of diffraction orders (ie M × N). Moreover, according to the three-dimensional image display apparatus 1A of the first embodiment, spatial and temporal filtering is performed, so that the temporal characteristics of the three-dimensional image display apparatus are changed to the spatial characteristics of the three-dimensional image display apparatus. Can be converted. In addition, a stereoscopic image can be obtained without using a diffusion screen or the like. Furthermore, it is possible to provide an appropriate stereoscopic image for observation from any direction. In addition, since a group of rays (a group of rays having parallax information) can be generated and scattered at a spatially high density, it is possible to provide a fine spatial image close to the visual recognition limit.

  Example 2 relates to a three-dimensional image display device according to the first and second aspects of the present invention. The three-dimensional image display apparatus according to the second embodiment changes the traveling direction of the light beam emitted from the optical system, instead of including a transflective mirror that changes the traveling direction of the light beam emitted from the optical system, and optical It differs from the three-dimensional image display device described in the first embodiment in that it includes a light beam control means for controlling the light collection state at the observation point of the light beam emitted from the system. Other constituent elements in the three-dimensional image display apparatus according to the second embodiment are the same as the constituent elements of the three-dimensional image display apparatus described in the first embodiment. Therefore, such differences will be described below.

  In the three-dimensional image display apparatus according to the second embodiment, as shown in FIG. 2A, the light beam control means includes a concave mirror 92 having a concave reflecting surface. The light collection state at the observation point of the light beam emitted from the optical system is controlled by the curvature of the concave mirror. The concave mirror 92 in the second embodiment may be a total reflection type mirror or a semi-transmission type mirror. Thus, by using the concave mirror 92 as the light beam control means, the light beam emitted from the optical system and reflected by the concave mirror 92 is condensed in a certain spatial region.

  Alternatively, as shown in FIG. 2B, the light beam control means includes a lens 93 on which a light beam emitted from the optical system is incident, and a mirror 94 (a plane mirror or a mirror) on which the light beam emitted from the lens 93 is incident. It is a concave mirror and is composed of a total reflection type mirror or a semi-transmission type mirror). Thus, by providing the lens 93, the light beam reflected by the mirror 94 is condensed in a certain spatial region. The lens 94 can be composed of, for example, a biconvex lens, a plano-convex lens, or a meniscus convex lens, or may be composed of a Fresnel lens.

  Alternatively, as shown in FIG. 2C, the light beam control means is composed of a mirror 94 (a plane mirror or a concave mirror, and a total reflection type mirror or a semi-transmission type mirror). , A detection means (specifically, for example, a camera equipped with a CCD element) 95 for detecting an observation point is provided, and the observation point detection result (specifically, the face of the observer or the like) Based on the detection of the pupil, the position of the mirror 95 is controlled. The detection means 95 can detect the observer's face and pupil based on a known method, and the control of the position of the mirror 95 based on the observation point detection result of the detection means 95 is also a known method and control. This can be done based on the mechanism. These detections and controls are performed by a personal computer (not shown).

  Alternatively, the light control means includes a lens on which light emitted from the optical system is incident, and a mirror on which the light emitted from the lens is incident (a flat mirror or a concave mirror, and a total reflection type mirror or a semi-transmission type). The light beam control means further includes a detection means for detecting the observation point, and the detection point detection result of the detection means (specifically, detection of the face and pupil of the observer) Based on this, it is possible to control the condensing state of the lens. The lens condensing state can be controlled by, for example, a method of moving the optical axis or image forming point of the lens by moving the lens, the lens moving mechanism, the lens moving method, and the lens movement control. Can be a known movement mechanism, movement method, and movement control.

  By the way, when the observer's pupil or face is located in the space area where the light rays are collected and the observer's face hardly moves (specifically, for example, the observer is sitting on a chair). In some cases, even if a group of rays (a group of rays having parallax information) necessary for displaying a stereoscopic image is spatially generated and scattered at a lower density, it is close to the same quality as an object in the real world. It is possible to obtain a stereoscopic image using light rays, and it is possible to reduce the burden on the image data processing system in the three-dimensional image display device. That is, as shown in the conceptual diagram of FIG. 50A, when an observer views a stereoscopic image from various positions, a group of light beams necessary for displaying the stereoscopic image is spatially increased at a higher density. Need to be generated and sprayed. On the other hand, as shown in the conceptual diagram of FIG. 50B, when the observer views the stereoscopic image from a predetermined position, the light beams necessary for displaying the stereoscopic image are spatially reduced at a lower density. Generate and spread. Therefore, since the light emission region is limited, the number of light rays can be reduced without reducing the light density near the observer. As a result, the burden on the image data processing system in the three-dimensional image display device can be reduced.

  Note that the light beam to be emitted from the optical system may be controlled based on the observation point detection result of the detection means. Specifically, for example, in the spatial filter SF having M × N opening / closing controllable openings 51, based on the observation point detection result (specifically, detection of the face and pupil of the observer), the open state What is necessary is just to restrict | limit the opening part 51 which should be taken. More specifically, for example, when the observer's pupil is located at a position where the image emitted from the (3, 3) -th opening 51 is mainly viewed, for example, the (1, 1) -th opening (51) to (1,5) th opening 51, (2,1) th to 51st (2,5) th opening 51, (3,1) th opening 51 To (3, 5) th opening 51, (4,1) th opening 51 to (4,5) th opening 51, (5,1) th opening 51 to Control may be performed such that the opening and closing of the (5, 5) -th opening 51 is controlled and the other openings 51 are closed. This also makes it possible to generate and scatter light groups necessary for displaying a stereoscopic image at a lower density in space. Therefore, since the light emission region is limited, the number of light rays can be reduced without reducing the light density near the observer. As a result, the burden on the image data processing system in the three-dimensional image display device can be reduced.

  Example 3 relates to a three-dimensional image display apparatus according to the first and third aspects of the present invention. A conceptual diagram of the three-dimensional image display device of Example 3 is shown in FIG. In FIG. 12, a transflective mirror 90 is illustrated.

  The third to twelfth embodiments described below basically include a transflective mirror that changes the traveling direction of the light beam emitted from the optical system described in the first embodiment. The light beam control means for changing the traveling direction of the light beam emitted from the optical system described in the second embodiment and controlling the light collection state at the observation point of the light beam emitted from the optical system is provided. Accordingly, in the third to twelfth embodiments described below, only differences in the configuration and structure of the three-dimensional image display device will be described.

  Unlike the liquid crystal display device according to the first embodiment, the light modulation unit 130 according to the third embodiment is a one-dimensional spatial light modulator (specifically, a PD (for example, 1920) divided one-dimensional image). , Diffraction grating-light modulation device 201); a one-dimensional spatial light modulator (diffraction grating-light modulation device 201), which is generated by a two-dimensionally developed (scanned) P-dimensional one-dimensional image. ), A scanning optical system (specifically, scan mirror 205) that forms a P × Q partitioned two-dimensional image; and a spatial frequency in the generated two-dimensional image arranged on the two-dimensional image generation surface. Is provided with a grating filter (diffraction grating filter) 132 that emits along a diffraction angle corresponding to a plurality of diffraction orders (specifically, the total number M × N). Here, M × N sets of diffracted light are generated by the grating filter 132 for each section of the two-dimensional image formed by the scanning optical system (scan mirror 205) and partitioned into P × Q. The grating filter 132 may be composed of an amplitude grating or may be composed of a phase grating. In the fifth, seventh, and ninth embodiments described later, the configuration and structure of the light modulating unit 130 can be the same.

Alternatively, the three-dimensional image display apparatus according to the third embodiment will be described along the components of the three-dimensional image display apparatus according to the third aspect of the present invention. It is a display device. And this optical system
(A) A one-dimensional spatial light modulator (specifically, a diffraction grating-light modulation device 201) having P pixels along the X direction and generating a one-dimensional image; A scanning optical system (specifically, a scan mirror 205) that expands the generated one-dimensional image two-dimensionally to generate a two-dimensional image; and a two-dimensional image generation surface, Diffracted light generating means (specifically, grating filter 132) for generating diffracted light of M sets from the m-th order to the m'-th order (where m and m 'are integers and M is a positive integer). A two-dimensional image forming apparatus 130 comprising:
(B) a first lens (specifically, a convex lens in Example 3) L ₁ in which diffracted light generating means is disposed on its front focal plane;
(C) M × N lenses arranged on the rear focal plane of the first lens L ₁ , M in the X direction and N in the Y direction (where N is a positive integer) A spatial filter SF having an opening 51 that can be controlled to open and close,
(D) a second lens (specifically, a convex lens in Example 3) L ₂ having a spatial filter SF disposed on the front focal plane thereof, and
(E) a third lens (specifically, a convex lens in Example 3) L ₃ whose front focal point is located at the rear focal point of the second lens L ₂ ;
It has.

  Here, it is assumed that the one-dimensional image extends in the X direction. The scanning direction is the Y direction, and the two-dimensional image is generated along the X direction and the Y direction. However, alternatively, the X direction and the Y direction may be exchanged. The same applies to Example 5, Example 7, and Example 9 described later. In FIG. 12, or FIGS. 18, 24, and 28 described later, the illumination optical system 20 is not shown.

  A conceptual diagram of a light modulation means (two-dimensional image forming apparatus) 130 including a diffraction grating-light modulation device is shown in FIG. That is, the light modulation means 130 of the third embodiment is incident on the light source 10 that emits a laser, a condensing lens (not shown) that condenses the light emitted from the light source 10, and light that has passed through the condensing lens. Diffraction grating-light modulation device 201, lens 203 through which light emitted from diffraction grating-light modulation device 201 passes, spatial filter 204, and imaging lens that forms an image of one light beam that has passed through spatial filter 204 (not shown) I.e., a scanning mirror 205 that scans one light beam that has passed through the imaging lens.

  The one-dimensional spatial light modulator (one-dimensional image forming apparatus, diffraction grating-light modulation apparatus 201) generates a one-dimensional image by diffracting light from the light source 10. More specifically, the diffraction grating-light modulation device 201 includes a diffraction grating-light modulation element (GLV) 210 arranged in a one-dimensional array. The diffraction grating-light modulation element 210 is manufactured by applying a micromachine manufacturing technique, is composed of a reflective diffraction grating, has an optical switching action, and electrically controls on / off control of light. To display the image. In the light modulation means (two-dimensional image forming apparatus) 130, the light emitted from each of the diffraction grating-light modulation elements 210 is scanned by the scan mirror 205 formed of a galvano mirror or a polygon mirror to be two-dimensional. Get an image. Accordingly, in order to display a two-dimensional image composed of P × Q (for example, 1920 × 1080) pixels (pixels), the diffraction grating-light modulation from the P (= 1920) diffraction grating-light modulation elements 210 is performed. The apparatus 201 may be configured.

It is necessary to generate diffracted light based on the two-dimensional image obtained by scanning with the scan mirror 205. Therefore, diffracted light is generated by arranging an amplitude type or phase type filter on a two-dimensionally developed surface. Specifically, the two-dimensional image obtained by scanning with the scan mirror 205 passes through the scanning lens system 131 and enters a grating filter (diffraction grating filter) 132 disposed on the generation surface of the two-dimensional image. In the lattice filter 132, M × N sets of diffracted light are generated for each section of the two-dimensional image partitioned into P × Q. That is, the spatial frequency in the generated two-dimensional image is emitted from the grating filter 132 along diffraction angles corresponding to a plurality of diffraction orders generated from each section (corresponding to a pixel) of the grating filter 132. The grating filter 132 is disposed on the front focal plane of the first lens L ₁ having a focal length f ₁ .

When a one-dimensional spatial light modulator (one-dimensional image forming apparatus) is used, since the generated image is one-dimensional, diffraction also occurs in the one-dimensional space. Therefore, an optical system intended to diffuse the obtained diffracted light in the Y direction is required. In the three-dimensional image display device according to the third embodiment, the diffracted light generated in the one-dimensional direction is arranged in the two-dimensional direction downstream (observer side) from the third lens L ₃ (conjugate image forming means 60). A member (also referred to as an anisotropic diffusion filter, an anisotropic diffusion film, or an anisotropic diffusion sheet) 133 that causes anisotropic light diffusion to be diffused is disposed.

  Except for the above points, the configuration and structure of the three-dimensional image display apparatus according to the third embodiment can be the same as the configuration and structure of the three-dimensional image display apparatus described in the first embodiment. To do. The configuration and structure of the diffraction grating-light modulation element 210 will be described later.

  Example 4 relates to a three-dimensional image display apparatus according to the fourth and fifth aspects of the present invention. FIG. 14, FIG. 15 and FIG. 16 show conceptual diagrams of a three-dimensional image display apparatus of Example 4 for monochromatic display. In FIG. 14, the optical axis is the z axis, the orthogonal coordinates in the plane orthogonal to the z axis are the x axis and the y axis, the direction parallel to the x axis is the X direction, and the direction parallel to the y axis is Y. The direction. The X direction is, for example, the horizontal direction in the 3D image display device, and the Y direction is, for example, the vertical direction in the 3D image display device. Here, FIG. 14 is a conceptual diagram of the three-dimensional image display apparatus of Example 4 on the yz plane. The conceptual diagram of the three-dimensional image display apparatus of Example 4 in the xz plane is substantially the same as FIG. FIG. 15 is a conceptual diagram of the three-dimensional image display apparatus according to the fourth embodiment when viewed obliquely. FIG. 16 schematically illustrates the arrangement state of the components of the three-dimensional image display apparatus according to the fourth embodiment. FIG. 16 illustrates a transflective mirror 90 as an example.

  Even in the three-dimensional image display device 1B of the fourth embodiment, the three-dimensional image display device alone provided with the components shown in FIGS. 14, 15, and 16 is spatially compared with the conventional technology. And it is possible to generate and form a large number of light beams. The three-dimensional image display apparatus 1B of the fourth embodiment is a single three-dimensional image display apparatus, and a large number (M × N) of projector units 301 shown in FIG. 52 are arranged in parallel in the horizontal direction and the vertical direction. It has a function equivalent to the device. For example, when the multi-unit method is adopted, as many as the number of divided three-dimensional images, the three-dimensional image display device 1B of Embodiment 4 may be provided as shown in FIG. In FIG. 51, an apparatus provided with 4 × 4 = 16 three-dimensional image display apparatus 1B of the fourth embodiment is illustrated.

Describing along the components of the three-dimensional image display device according to the fourth aspect of the present invention, the three-dimensional image display device 1B of Example 4 is a three-dimensional image display device including a light source 10 and an optical system. It is. And this optical system
(A) A plurality of pixels 31 are provided, light from the light source 10 is modulated by each pixel 31 to generate a two-dimensional image, and a spatial frequency in the generated two-dimensional image is generated from the plurality of pixels 31. Light modulating means 30 for emitting along a diffraction angle corresponding to the diffraction order;
(B) Fourier transform of the spatial frequency in the two-dimensional image emitted from the light modulation means 30 to generate a number of Fourier transform images corresponding to a plurality of diffraction orders generated from the respective pixels 31, and these Fourier transform images Only a predetermined Fourier transform image (for example, a Fourier transform image corresponding to the first order diffraction using the 0th order diffraction of the plane wave component as the carrier frequency) is selected, and the selected Fourier transform image is further converted to the inverse Fourier. An image limiting / generating unit 32 that converts and forms a conjugate image of the two-dimensional image generated by the light modulation unit 30 (a real image of the two-dimensional image);
(C) An oversampling filter that has a plurality of aperture regions 34 and emits spatial frequencies in a conjugate image of a two-dimensional image along diffraction angles corresponding to a plurality of diffraction orders generated from the aperture regions 34 (diffracted light generation Member) OSF,
(D) Fourier transform image that Fourier-transforms the spatial frequency in the conjugate image of the two-dimensional image emitted from the oversampling filter OSF to generate a number of Fourier transform images corresponding to a plurality of diffraction orders generated from each aperture region 34. Forming means 40,
(E) Fourier transform image selection means 50 for selecting a Fourier transform image corresponding to a desired diffraction order among Fourier transform images generated in a number corresponding to a plurality of diffraction orders generated from each aperture region 34; and
(F) conjugate image forming means 60 for forming a conjugate image of the Fourier transform image selected by the Fourier transform image selection means 50;
It has.

Further, the conjugate image forming means 60 performs inverse Fourier transform on the Fourier transform image selected by the Fourier transform image selection means 50 to thereby obtain a conjugate image (hereinafter referred to as a conjugate image of the two-dimensional image generated by the image restriction / generation means 32). Inverse Fourier transform means (specifically, a fourth lens L _{4 to be} described later) for forming a “conjugate image of a two-dimensional image” may be provided. The Fourier transform image forming means 40 is composed of a lens, an oversampling filter OSF is disposed on the front focal plane of the lens, and a Fourier transform image selecting means 50 is disposed on the rear focal plane of the lens. The Fourier transform image selection means 50 has a number of openings 51 that can be controlled to be opened and closed corresponding to a plurality of diffraction orders generated from each opening region 34.

  Here, the spatial frequency in the two-dimensional image corresponds to image information using the spatial frequency of the pixel structure as the carrier frequency. The spatial frequency in the conjugate image of the two-dimensional image is a spatial frequency obtained by removing the spatial frequency of the pixel structure from the spatial frequency in the two-dimensional image.

Further, the three-dimensional image display device 1B according to the fourth embodiment will be described along the components of the three-dimensional image display device according to the fifth aspect of the present invention. It is a display device. And this optical system
(A) Having apertures (number: P × Q) arranged in a two-dimensional matrix along the X and Y directions, and controlling the passage, reflection, or diffraction of light from the light source 10 for each aperture. A two-dimensional image forming apparatus 30 that generates a two-dimensional image and generates diffracted light of a plurality of diffraction orders for each aperture based on the two-dimensional image,
(B) a first lens L ₁ in which a two-dimensional image forming apparatus 30 is disposed on the front focal plane;
(C) Only the diffracted light of a predetermined diffraction order (for example, a Fourier transform image corresponding to the first order diffraction using the 0th order diffraction of the plane wave component as the carrier frequency) is disposed on the rear focal plane of the first lens L _1. A scattering diffraction limiting aperture 33 to be passed,
(D) a second lens L ₂ in which a scattering diffraction limiting aperture 33 is arranged on the front focal plane;
(E) P _OSF × Q _OSF pieces arranged in the rear focal plane of the second lens L ₂ and arranged in a two-dimensional matrix along the X direction and the Y direction (however, P _OSF and Q _OSF are arbitrary) (A positive integer) of the aperture region 34, and based on the conjugate image of the two-dimensional image generated by the second lens L ₂ , for each aperture region 34, the mth to m′th positions along the X direction. M sets up to the following (where m and m ′ are integers and M is a positive integer), N sets from the n-th order to the n′-th order along the Y direction (where n and n ′ Is an integer and N is a positive integer), a total, M × N oversampling filter (diffracted light generating member) OSF that generates diffracted light,
(F) a third lens L _{3 having} an oversampling filter OSF disposed on its front focal plane;
(G) M × N open / close-controllable openings 51 are arranged in the rear focal plane of the third lens L ₃ and M in the X direction and N in the Y direction. A spatial filter SF,
(H) a fourth lens L ₄ having a spatial filter SF disposed on the front focal plane thereof;
(I) a fifth lens L ₅ whose front focal point is located at the rear focal point of the fourth lens L ₄ ;
It has.

In Example 4, the first lens L ₁ , the second lens L ₂ , the third lens L ₃ , the fourth lens L _4, and the fifth lens L ₅ are specifically described. Consists of a convex lens. The image limiting / generating unit 32 includes two lenses (first lens L ₁ and second lens L ₂ ), and these two lenses (first lens L ₁ and second lens). L ₂ ) and is configured to include a scattering diffraction limiting aperture 33 that passes only a predetermined Fourier transform image (for example, a Fourier transform image corresponding to the first order diffraction using the zeroth order diffraction of the plane wave component as a carrier frequency). Has been. Furthermore, the oversampling filter (diffraction light generation member) OSF consists grating filter (grating filter), and more specifically, corresponds to a P _OSF × Q _OSF number of recesses (opening region into a flat glass, the planar shape Has a structure formed in a two-dimensional matrix. That is, the oversampling filter (diffracted light generating member) OSF is composed of a phase grating. The same applies to Example 5 and Example 12 described later.

Here, in Example 4 or Example 5 or Example 12 described later, P _OSF = 2048, Q _OSF = 1536, P = 1024, Q = 768, m = -4, m ′. = 4, M = m'-m + 1 = 9, n = -4, n '= 4, and N = n'-n + 1 = 9. However, it is not limited to these values. When the components of the three-dimensional image display device according to the fourth aspect of the present invention are compared with the components of the three-dimensional image display device according to the fifth or sixth aspect of the present invention, the light modulation means 30 is Corresponding to the two-dimensional image forming apparatus 30, the image limiting / generating unit 32 corresponds to the first lens L ₁ , the scattering diffraction limiting aperture 33 and the second lens L ₂ , and the Fourier transform image forming unit 40 corresponds to the first lens L ₁ . corresponding to the third lens L _3, the Fourier transform image selection means 50 corresponds to the spatial filter SF, the inverse Fourier transform means corresponds to the fourth lens L _4, the conjugate image formation means 60 fourth lens L ₄ And the fifth lens L ₅ . Therefore, for convenience, the two-dimensional image forming apparatus 30, the first lens L _1, scattering diffraction limiting aperture 33, a second lens L _2, the third lens L _3, the spatial filter SF, the fourth lens L ₄ And the fifth lens L ₅ will be described below.

  Similar to the first embodiment, an illumination optical system 20 for shaping light emitted from the light source 10 is disposed between the light source 10 and the two-dimensional image forming apparatus 30. The two-dimensional image forming apparatus 30 is illuminated with light (illumination light) emitted from the light source 10 and passed through the illumination optical system 20. The illumination optical system 20 will be described later.

  The two-dimensional image forming apparatus 30 includes a two-dimensional spatial light modulator having a plurality of pixels 31 arranged two-dimensionally, and each pixel 31 has an opening. Specifically, the two-dimensional image forming apparatus 30 or the two-dimensional spatial light modulator is two-dimensionally arranged, that is, P × Q arranged in a two-dimensional matrix along the X direction and the Y direction. It consists of a transmissive liquid crystal display device having a number of pixels 31, and each pixel 31 is provided with an opening.

Similar to the first embodiment, one pixel 31 is an overlapping region of the transparent first electrode and the transparent second electrode and includes a region including a liquid crystal cell. Then, by operating the liquid crystal cell as a kind of light shutter (light valve), that is, by controlling the light transmittance of each pixel 31, the light transmittance of the light emitted from the light source 10 is controlled, As a whole, a two-dimensional image can be obtained. In the overlapping region of the transparent first electrode and the transparent second electrode, a rectangular opening is provided. When light emitted from the light source 10 passes through the opening, Fraunhofer diffraction occurs. ₀ × N ₀ diffracted light is generated. In other words, since the number of pixels 31 is P × Q, it can be considered that a total of (P × Q × M ₀ × N ₀ ) diffracted lights are generated. In the two-dimensional image forming apparatus 30, the spatial frequency in the two-dimensional image is emitted from the two-dimensional image forming apparatus 30 along diffraction angles corresponding to a plurality of diffraction orders (total M ₀ × N ₀ ) generated from each pixel 31. Is done. The diffraction angle varies depending on the spatial frequency in the two-dimensional image.

A two-dimensional image forming apparatus 30 is arranged on the front focal plane (focal plane on the light source side) of the first lens L ₁ having a focal length f _1, and the rear focal plane (observation) of the first lens L _1. Scattering diffraction limiting aperture 33 is arranged on the focal plane on the person side. A number of Fourier transform images corresponding to a plurality of diffraction orders are generated by the first lens L ₁ , and these Fourier transform images are formed in a plane where the scattering diffraction limiting aperture 33 is located. Then, only diffracted light of a predetermined diffraction order (for example, a Fourier transform image corresponding to the first order diffraction using the 0th order diffraction of the plane wave component as the carrier frequency) passes through the scattering diffraction limiting opening 33. A scattering diffraction limiting aperture 33 is disposed on the front focal plane of the second lens L ₂ having a focal length f _2, and an oversampling filter OSF is disposed on the rear focal plane of the second lens L _2. Has been placed. Furthermore, an oversampling filter OSF is disposed on the front focal plane of the third lens L ₃ having a focal length f _3, and a spatial filter SF is disposed on the rear focal plane of the third lens L _3. ing. The third lens L ₃ generates M × N = 81 Fourier transform images, which are numbers corresponding to a plurality of diffraction orders generated from the respective aperture regions 34, and these Fourier transform images are generated on the spatial filter SF. Form an image. In FIG. 15, for the sake of convenience, 64 Fourier transform images are shown as dots.

  Specifically, the spatial filter SF is a spatial filter capable of temporal opening and closing control for spatially and temporally filtering the Fourier transform image. More specifically, the spatial filter SF has a number of openings 51 that can be controlled to open and close (specifically, M × N = 81) corresponding to a plurality of diffraction orders generated from each opening region 34. In the spatial filter SF, one Fourier corresponding to a desired diffraction order is obtained by opening one desired opening 51 in synchronization with the generation timing of a two-dimensional image by the two-dimensional image forming apparatus 30. Select the conversion image. More specifically, the spatial filter SF is, for example, a transmissive liquid crystal display device or a reflective liquid crystal display device using a ferroelectric liquid crystal having M × N pixels, or a movable mirror is a two-dimensional matrix. It can be composed of a two-dimensional type MEMS including devices arranged in a shape. A schematic front view of the spatial filter SF formed of the liquid crystal display device is the same as that shown in FIG.

As described above, specifically, the conjugate image forming unit 60 includes the fourth lens L ₄ and the fifth lens L ₅ . Then, the fourth lens L ₄ having the focal length f ₄ performs inverse Fourier transform on the Fourier transform image filtered by the spatial filter SF, thereby conjugated image of the two-dimensional image generated by the second lens L ₂ . The real image RI is formed. The fifth lens L ₅ having the focal length f ₅ forms a conjugate image CI of the Fourier transform image filtered by the spatial filter SF.

The fourth lens L ₄ is disposed on the front focal plane so that the spatial filter SF is positioned, and a real image of a conjugate image of the two-dimensional image generated by the second lens L ₂ is disposed on the rear focal plane. Arranged to form an RI. The magnification of the real image RI obtained here with respect to the real image formed by the second lens L ₂ can be changed by arbitrarily selecting the focal length f ₄ of the fourth lens L ₄ .

On the other hand, the fifth lens L ₅ is arranged such that its front focal plane coincides with the rear focal plane of the fourth lens L ₄ , and a conjugate image CI of the Fourier transform image is formed on the rear focal plane. Are arranged as follows. Here, since the rear focal plane of the fifth lens L ₅ is a conjugate plane of the spatial filter SF, a conjugate image of a two-dimensional image is output from a portion corresponding to one opening 51 on the spatial filter SF. It is equivalent to what is done. The amount of light rays finally generated / output is the number of pixels (P × Q), and a plurality of diffraction orders (specifically, the light rays that have passed through the scattering diffraction limiting aperture 33 are transmitted through the optical system. Specifically, it can be defined by an amount multiplied by M × N). Further, although the back focal plane of the fifth lens L ₅ conjugate image CI of the Fourier transform image is formed, in the back focal plane of the fifth lens L _5, orderly group of light beams are two-dimensionally It can be regarded as being placed. That is, as a whole, the projector unit 301 shown in FIG. 52 is arranged for a plurality of diffraction orders (specifically, M × N) on the rear focal plane of the fifth lens L ₅ . Is equivalent to

As schematically shown in FIG. 7, a single pixel 31 in the two-dimensional image forming apparatus 30 generates a total of M ₀ × N ₀ sets of diffracted light along the X and Y directions. In FIG. 7, only the diffracted light of the 0th order light (n ₀ = 0), ± 1st order light (n ₀ = ± 1), and ± 2nd order light (n ₀ = ± 2) is shown as a representative. However, actually, higher-order diffracted light is generated, and a stereoscopic image is finally formed based on a part of the diffracted light. Here, all image information (information of all pixels) of the two-dimensional image generated by the two-dimensional image forming apparatus 30 is collected in the diffracted light (light beam) of each diffraction order. A plurality of light ray groups generated by diffraction from the same pixel on the two-dimensional image forming apparatus 30 all have the same image information at the same time. In other words, in the two-dimensional image forming apparatus 30 including a transmissive liquid crystal display device having P × Q pixels 31, the light from the light source 10 is modulated by each pixel 31 to generate a two-dimensional image. In addition, the spatial frequency in the generated two-dimensional image is emitted along diffraction angles corresponding to a plurality of diffraction orders (total M ₀ × N ₀ ) generated from each pixel 31. That is, a kind of M ₀ × N ₀ copies of the two-dimensional image are emitted from the two-dimensional image forming apparatus 30 along diffraction angles corresponding to a plurality of diffraction orders (total M ₀ × N ₀ ).

Then, the spatial frequency in the two-dimensional image emitted from the two-dimensional image forming apparatus 30 is Fourier-transformed by the first lens L ₁ , and a number of Fourier-transform images corresponding to a plurality of diffraction orders generated from each pixel 31 are generated. Is done. Of these Fourier transform images, only a predetermined Fourier transform image (for example, a Fourier transform image corresponding to the first order diffraction using the zeroth order diffraction of the plane wave component as the carrier frequency) passes through the scattering diffraction limiting aperture 33. Further, the selected Fourier transform image is subjected to inverse Fourier transform by the second lens L ₂ to form a conjugate image of the two-dimensional image generated by the two-dimensional image forming apparatus 30, and the conjugate of the two-dimensional image. The image is formed on the oversampling filter OSF. Note that the spatial frequency in the two-dimensional image corresponds to image information in which the spatial frequency of the pixel structure is a carrier frequency, but only in a region of image information having a 0th-order plane wave as a carrier wave (that is, the maximum spatial frequency of the pixel structure). In other words, it is obtained as first-order diffraction using the 0th-order diffraction of the plane wave component as the carrier frequency, and the spatial frequency of the pixel structure (aperture structure) of the light modulation means Less than half of the spatial frequency passes through the scattering diffraction limiting aperture 33. Thus, the conjugate image of the two-dimensional image formed on the oversampling filter OSF does not include the pixel structure of the two-dimensional image forming apparatus 30, while the two-dimensional image generated by the two-dimensional image forming apparatus 30. All of the spatial frequencies in the image are included.

The spatial frequency in the conjugate image of the two-dimensional image in which all the image information of the two-dimensional image generated by the two-dimensional image forming apparatus 30 is aggregated corresponds to a plurality of diffraction orders generated from each aperture region 34 in the oversampling filter OSF. The light is emitted along the diffraction angle and is Fourier transformed by the third lens L ₃ to generate a number of Fourier transform images corresponding to a plurality of diffraction orders (total M × N). The Fourier transform image is generated on the spatial filter SF. Is imaged. In the third lens L ₃ , a Fourier transform image having a spatial frequency in a conjugate image of a two-dimensional image emitted along diffraction angles corresponding to a plurality of diffraction orders is generated. A converted image can be obtained.

Here, the wavelength of the light (illumination light) emitted from the light source 10 is λ (mm), the spatial frequency in the conjugate image of the two-dimensional image generated by the second lens L ₂ is ν (lp / mm), If the focal length of the _third lens L ₃ is f ₃ (mm), the rear focal plane of the third lens L ₃ has a distance Y ₁ (mm) from the optical axis represented by the following formula (B). Light having a spatial frequency ν (Fourier transform image) appears at the position.

The condensing state in the third lens L ₃ is schematically shown in FIG. In FIG. 17, “Y ₀ ” indicates the length in the y-axis direction of the conjugate image of the two-dimensional image generated by the second lens L ₂ , and “Y ₁ ” indicates the second lens L _2. The space | interval of the y-axis direction of the Fourier-transform image on the spatial filter SF based on the conjugate image of the two-dimensional image produced | generated by FIG. Further, the 0th-order diffracted light is indicated by a solid line, the first-order diffracted light is indicated by a dotted line, and the second-order diffracted light is indicated by a one-dot chain line. In other words, the diffracted light of each diffraction order, in other words, the Fourier transform image generated by the number corresponding to the diffraction order is condensed by the third lens L ₃ on different openings 51 on the spatial filter SF (FIG. 15). As described above, the number of the openings 51 is M × N = 81. The condensing angle to the spatial filter SF (the divergence angle after being emitted from the spatial filter SF and also the viewing angle) θ is P _{OSF in a} Fourier transform image (or diffracted light) having the same diffraction order. × Q It is the same in the _OSF open regions 34 and can be obtained from the following equation (C). On the spatial filter SF, the interval between Fourier transform images of adjacent diffraction orders can be obtained from the equation (B). By arbitrarily selecting the focal length f ₃ of the third lens L ₃ from the equation (B), it is possible to change the position of the Fourier transform image (image formation position on the spatial filter SF). Incidentally, in the formula (C), "w" is the length in the Y direction of the conjugate image of the two-dimensional image projected on the oversampling filter OSF, optionally a focal length f ₂ of the second lens L ₂ It can be changed by selecting.

Y ₁ = f ₃ · λ · ν (B)
θ = 2 × arctan (w / 2f ₃ ) (C)

In the third lens L ₃ , in order to transmit the spatial frequency in the conjugate image of the two-dimensional image emitted along the diffraction angles corresponding to the plurality of diffraction orders generated from each aperture region 34, the diffraction order to be used is set. Accordingly, it is necessary to select the aperture ratio NA of the third lens L _{3, and} the aperture ratio of all the lenses after the _third lens L ₃ is the aperture ratio of the third lens L ₃ regardless of the focal length. It is required to be greater than or equal to NA.

The size of the opening 51 may be the same value as the value of Y ₁ in the formula (B). As an example, the wavelength λ of the illumination light 532 nm, the third lens L ₃ of the focal length f ₃ of 50 mm, when the 13μm~14μm about the size of the opening area 34 in the oversampling filter OSF, the value of Y ₁ is about 2 mm. This means that a Fourier transform image corresponding to each diffraction order can be obtained at a high density of about 2 mm on the spatial filter SF. In other words, 9 × 9 = 81 Fourier transform images can be obtained on the spatial filter SF at intervals of about 2 mm in both the X direction and the Y direction.

Here, the spatial frequency ν in the conjugate image of the two-dimensional image is the continuous 2 constituting the oversampling filter OSF at most because the oversampling filter OSF is composed of P _OSF × Q _OSF opening regions 34. It is a frequency having a period composed of two open regions 34.

A schematic front view of the two-dimensional image forming apparatus 30 having the lowest spatial frequency in the conjugate image of the two-dimensional image is the same as that shown in FIG. 9A, and in this case, the third The frequency characteristic of the light intensity of the Fourier transform image formed by the lens L ₃ is the same as that shown in FIG. On the other hand, a schematic front view of the two-dimensional image forming apparatus 30 having the highest spatial frequency in the conjugate image of the two-dimensional image is the same as that shown in FIG. The frequency characteristic of the light intensity of the Fourier transform image formed by the _third lens L ₃ is the same as that shown in FIG. Furthermore, the distribution of the Fourier transform image on the spatial filter SF (on the xy plane) is the same as shown in FIGS. 11A, 11B, and 11C. Further, the planar shape of the opening 51 in the spatial filter SF may be the same as that in the first embodiment.

By the way, the state with the highest spatial frequency is a case where all pixels alternately display black display and white display, as shown in FIG. 9B. In addition, the relationship between the spatial frequency of the aperture region structure in the oversampling filter OSF and the spatial frequency in the conjugate image of the two-dimensional image is as follows. That is, assuming that the aperture ratio of the aperture region 34 is 100%, the highest spatial frequency in the conjugate image of the two-dimensional image is (1/2) of the spatial frequency of the aperture region structure. When the aperture ratio of the aperture region 34 occupies a certain ratio (less than 100%), the highest spatial frequency in the conjugate image of the two-dimensional image is (1/2) of the spatial frequency of the aperture region structure. Below. Therefore, all the spatial frequencies in the conjugate image of the two-dimensional image appear up to the half of the periodic pattern interval due to the opening area structure appearing in the spatial filter SF. For this reason, all the openings 51 can be arranged without spatially interfering with each other. That is, for example, the (3,2) th aperture 51, while the Fourier transform image having a diffraction order of _{m 0 = 3, n 0 =} 2 enters, the _{m 0 = 3, n 0 =} 2 The Fourier transform image having the diffraction order does not enter the other openings 51. Thus, on the spatial filter SF having the independent opening 51 for each Fourier transform image, the spatial frequency in the conjugate image of the two-dimensional image exists in the Fourier transform image located at one opening 51, while the opening The spatial frequency in the conjugate image of the two-dimensional image is not lost due to the spatial limitation of the unit 51. Note that the spatial frequency of the aperture region structure can be regarded as the carrier frequency, and the spatial frequency in the conjugate image of the two-dimensional image corresponds to image information in which the spatial frequency of the aperture region structure is the carrier frequency.

  In the spatial filter SF, the opening / closing control of the opening 51 is performed in order to control the passage / non-passage of the M × N Fourier transform images. If the spatial filter SF is composed of, for example, a liquid crystal display device, the opening / closing control of the opening 51 can be performed by operating the liquid crystal cell as a kind of light shutter (light valve).

When the brightness of the obtained image is different depending on the diffraction order generated from the aperture region 34, as described above, a neutral density filter that attenuates a bright image with respect to the darkest image is used as the fifth lens. it may be arranged on the rear focal plane of the L _5.

  In the three-dimensional image display apparatus according to the fourth embodiment, a three-dimensional image display apparatus from which the oversampling filter OSF is removed is assumed for comparison. Such a three-dimensional image display device is referred to as a comparative three-dimensional image display device for convenience. The following description will be made by comparing the three-dimensional image display device of Example 4 with the comparative three-dimensional image display device.

Note that the wavelength of light (illumination light) emitted from the light source 10 is λ (mm), and the spatial frequency in the two-dimensional image generated by the two-dimensional image forming apparatus 30 is ν ₀ (lp / mm).

Incidentally, the projection angle (viewing angle) θ is an important parameter for determining the region of the stereoscopic image to be observed. On the other hand, the position and interval (Y ₁ ) of the Fourier transform image on the spatial filter SF are important parameters that determine the continuity of the displayed stereoscopic image and motion parallax and the scale (size) of the displayed stereoscopic image. is there. The larger the value of the projection angle (viewing angle) θ and the value of Y ₁ corresponding to the position and interval of the Fourier transform image on the spatial filter SF, the better.

Incidentally, the formula (B) described above, the variable that controls the Y ₁ is the wavelength of the light (illumination light) lambda, and the focal length f ₃ of the third lens L _3, further, the spatial frequency ν This is the spatial frequency ν ₀ in the two-dimensional image generated by the base two-dimensional image forming apparatus 30. Here, since the wavelength λ of the light (illumination light) changes in the color tone of the image, it cannot actually take an arbitrary value. Moreover, the wavelength of visible light is about 400 nm to about 700 nm, the amount of change is at most 1.75 times, and the operation region is narrow. Further, in order to increase the value of the spatial frequency ν ₀ , it is necessary to make the pixel pitch in the two-dimensional image forming apparatus 30 fine. However, making the pixel pitch in the two-dimensional image forming apparatus 30 fine is a reality. Is difficult. Therefore, in order to increase the value of Y ₁ in the formula (B), it is most realistic to increase the focal length f ₃ of the third lens L ₃ . However, when the focal length f ₃ is increased, the length w in the Y direction of the conjugate image of the two-dimensional image projected on the oversampling filter OSF is constant from the equation (C), that is, the second lens L _When the focal length f ₂ of ₂ is constant, the value of the projection angle (viewing angle) θ is small. That is, Expression (B) and Expression (C) are not independent, and the value of Y _{1 and} the value of the projection angle (viewing angle) θ are in a so-called trade-off relationship.

By the way, in the three-dimensional image display device 1B of the fourth embodiment, a two-dimensional image is generated by the light modulation means or the two-dimensional image forming device 30, and the spatial frequency ν ₀ in this two-dimensional image is two-dimensional. The value depends on the opening structure of the opening constituting the image forming apparatus. On the other hand, the spatial frequency ν in the conjugate image of this two-dimensional image depends on the opening region structure of the opening region 34 in the oversampling filter OSF, and P _OSF > P, Q _OSF > Q. The spatial frequency (carrier frequency) of the opening region structure in the oversampling filter OSF is higher than the spatial frequency (carrier frequency) of the pixel structure (opening structure) in the forming apparatus 30, and ν> ν ₀ . The oversampling filter OSF can be manufactured, for example, by directly forming a lattice pattern on a flat glass. Therefore, if the pitch of the lattice pattern is made fine, the carrier frequency can be increased, and the two-dimensional The value of the spatial frequency ν generated by the oversampling filter OSF in the conjugate image of the image can be easily increased. Therefore, the value of the spatial frequency ν can be easily increased, and the value of Y ₁ obtained from the equation (B) can be increased. Even if the focal length f ₃ of the third lens L ₃ is set short, the value of Y ₁ obtained from the equation (B) can be increased. On the other hand, since the focal length f ₃ of the third lens L ₃ can be set short, the value of the viewing angle θ obtained from the equation (C) can be increased. Alternatively, the value of w can be increased by appropriately setting the focal length f ₂ of the second lens L ₂ , and as a result, the value of the viewing angle θ obtained from the equation (C) can be increased. Can do.

As described above, in the three-dimensional image display device 1B according to the fourth embodiment, the value of Y _{1 and} the value of the projection angle (viewing angle) θ can be controlled independently. Therefore, it is possible to increase the scale (size) of the displayed stereoscopic image while expanding the area of the observed stereoscopic image. In addition, there is no need to change the wavelength of light from the light source, and there is no change in color tone due to wavelength variation. Further, there is essentially no need to change the focal length f ₃ of the third lens L ₃ .

For example, in the comparative three-dimensional image display device, the size of the two-dimensional image forming device 30 is 0.7 inches diagonal and has a square planar opening (P × Q = 1024 × 768). To do. Also, when the aperture interval is 14 μm, the wavelength λ of the light emitted from the light source 10 is 532 nm, and f ₂ = f ₃ = f ₄ = f ₅ = 50 mm, the space after passing through the fifth lens L ₅ The interval between the conjugate images on the conjugate plane of the filter SF is 1.9 mm, the viewing angle θ _Y corresponding to the Y direction of the two-dimensional image forming apparatus 30 is 16.1 degrees, and the field angle corresponding to the X direction of the two-dimensional image forming apparatus 30. The angle θ _X is 12.1 degrees.

Further, 100 mm in the three-dimensional image display apparatus for comparison, in order to increase the size of the conjugate image of the two-dimensional image formed by the second lens L _2, a focal length f ₂ of the second lens L ₂ In this case, the viewing angle θ _Y is 31.5 degrees and the viewing angle θ _X is 23.9 degrees, so that the viewing angle can be increased. However, since the size of the conjugate image of the two-dimensional image is doubled, the value of ν in the equation (B) is halved, so that the spatial filter SF after passing through the fifth lens L ₅ is used. The interval between the conjugate images on the conjugate plane is 0.95 mm. In this case, a light beam group having a spatial density higher than usual is generated, but since the generation area per one light beam group is ¼, the size of the observation image becomes ¼. .

Therefore, when an oversampling filter OSF composed of a diffraction filter having a square lattice having a spacing of 14 μm (= Y ₀ ) is arranged, a new spatial sampling for a conjugate image of a two-dimensional image magnified twice is performed. The spatial frequency is the same as the pixel interval of the original two-dimensional image forming apparatus 30, and the viewing angle θ _Y is 31.5 degrees and the viewing angle θ _X is 23.9 degrees, so that the viewing angle can be increased. In addition, the interval between the conjugate images on the conjugate plane of the spatial filter SF after passing through the fifth lens L ₅ can be 1.9 mm. That is, in this case, a light beam group having a spatial density higher than usual is generated, and the generation area per one light beam group does not change, and the size of the observation image does not change. This oversampling filter OSF can be produced simply by drawing a grid arranged in a two-dimensional matrix with a pitch of 14 μm on a flat glass.

As described above, according to the three-dimensional image display apparatus 1B of the fourth embodiment, the spatial frequency in the two-dimensional image generated by the light modulation unit (two-dimensional image forming apparatus) 30 corresponds to a plurality of diffraction orders. is the emitted along diffraction angle, only the Fourier transform image corresponding to a predetermined diffraction order is selected by the image restriction and generation means 32, the conjugate image is Fourier transformed image of the two-dimensional image generated by the second lens L ₂ The Fourier transform image obtained by Fourier transform by the forming means 40 (third lens L ₃ ) is spatially and temporally filtered by the Fourier transform image selection means 50 (spatial filter SF), Since the conjugate image CI of the filtered Fourier transform image is formed, it is spatially high without increasing the size of the entire three-dimensional image display device. Density and further in a state of being distributed in a plurality of directions can be generated and scattered light ray group. In addition, by providing the two-dimensional image forming apparatus 30 and the oversampling filter OSF, it is possible to increase the scale (size) of the displayed stereoscopic image while expanding the area of the observed stereoscopic image. In addition, individual light beams that are constituent elements of the light beam group can be controlled independently in terms of time and space. As a result, it is possible to obtain a three-dimensional image using light rays that are close to the same quality as real-world objects.

  Further, according to the three-dimensional image display device 1B of the fourth embodiment, since the light beam reproduction method is used, it is possible to provide a stereoscopic image that satisfies visual functions such as focus adjustment, convergence, and motion parallax. . Furthermore, according to the three-dimensional image display apparatus 1B of the fourth embodiment, since higher-order diffracted light is efficiently used, one image output device (two-dimensional image formation) is compared with the conventional image output method. Light rays (a kind of copy of the two-dimensional image) that can be controlled by the device 30) can be obtained by the oversampling filter OSF for a plurality of diffraction orders (ie M × N). Moreover, according to the three-dimensional image display device 1B of the fourth embodiment, spatial and temporal filtering is performed, so that the temporal characteristics of the three-dimensional image display device are changed to the spatial characteristics of the three-dimensional image display device. Can be converted. In addition, a stereoscopic image can be obtained without using a diffusion screen or the like. Furthermore, it is possible to provide an appropriate stereoscopic image for observation from any direction. In addition, since a group of rays can be generated and scattered at a spatially high density, a fine spatial image close to the visual recognition limit can be provided.

  Furthermore, in the three-dimensional image display device 1B of Example 4, the size of the conjugate image on the conjugate plane of the spatial filter SF after passing through the fifth lens and the projection angle (viewing angle) are independent. Can be controlled. Therefore, it is possible to increase the scale (size) of the displayed stereoscopic image while expanding the area of the observed stereoscopic image.

  Example 5 relates to a three-dimensional image display apparatus according to the fourth and sixth aspects of the present invention. A conceptual diagram of the three-dimensional image display device of Example 5 is shown in FIG. In FIG. 18, a semi-transmissive mirror 90 is illustrated.

Unlike the liquid crystal display device according to the fourth embodiment, the light modulation unit 130 according to the fifth embodiment is a one-dimensional spatial light modulator (specifically, a PD (for example, 1920) divided one-dimensional image). , Diffraction grating-light modulation device 201); a one-dimensional spatial light modulator (diffraction grating-light modulation device 201), which is generated by a two-dimensionally developed (scanned) P-dimensional one-dimensional image. ), A scanning optical system (specifically, scan mirror 205) that forms a P × Q partitioned two-dimensional image; and a spatial frequency in the generated two-dimensional image arranged on the two-dimensional image generation surface. Is provided along a diffraction angle corresponding to a plurality of diffraction orders (specifically, total number M ₀ × N ₀ ). Here, M ₀ × N ₀ sets of diffracted light are generated by the grating filter 132 for each section of the two-dimensional image formed by the scanning optical system (scan mirror 205) and partitioned into P × Q. The grating filter 132 may be composed of an amplitude grating or a phase grating.

Alternatively, the three-dimensional image display device according to the fifth embodiment will be described along the components of the three-dimensional image display device according to the sixth aspect of the present invention. The three-dimensional image display device according to the fifth embodiment includes a light source 10 and an optical system. It is a display device. And this optical system
(A) A one-dimensional spatial light modulator that generates a one-dimensional image (specifically, a diffraction grating light modulator 201); two-dimensionally develops the one-dimensional image generated by the one-dimensional spatial light modulator. A scanning optical system that generates a two-dimensional image (specifically, a scan mirror 205); A two-dimensional image forming apparatus 130 comprising means (specifically, a lattice filter 132),
(B) a first lens L ₁ in which diffracted light generating means (grating filter 132) is disposed on the front focal plane;
(C) Only the diffracted light of a predetermined diffraction order (for example, a Fourier transform image corresponding to the first order diffraction using the 0th order diffraction of the plane wave component as the carrier frequency) is disposed on the rear focal plane of the first lens L _1. A scattering diffraction limiting aperture 33 to be passed,
(D) a second lens L ₂ in which a scattering diffraction limiting aperture 33 is arranged on the front focal plane;
(E) P _OSF × Q _OSF pieces arranged in the rear focal plane of the second lens L ₂ and arranged in a two-dimensional matrix along the X direction and the Y direction (however, P _OSF and Q _OSF are arbitrary) of a positive integer, it has an opening area of the P _OSF> P), based on the conjugate image of the two-dimensional image generated by the second lens L _2, each opening region, the along the X direction m M sets from the next to the m'th (where m and m 'are integers and M is a positive integer), N sets from the nth to the n'th (along the Y direction) , N and n ′ are integers, where N is a positive integer), a total, M × N oversampling filters OSF that generate diffracted light,
(F) a third lens L _{3 having} an oversampling filter OSF disposed on its front focal plane;
(G) M × N open / close-controllable openings 51 are arranged in the rear focal plane of the third lens L ₃ and M in the X direction and N in the Y direction. A spatial filter SF,
(H) a fourth lens L ₄ having a spatial filter SF disposed on the front focal plane thereof;
(I) a fifth lens L ₅ whose front focal point is located at the rear focal point of the fourth lens L ₄ ;
It has.

The conceptual diagram of the light modulation means (two-dimensional image forming apparatus) 130 including the diffraction grating-light modulation device is the same as that of the light modulation means 130 of the third embodiment shown in FIG. In the lattice filter 132, M ₀ × N ₀ sets of diffracted light are generated for each section of the two-dimensional image partitioned into P × Q.

  The one-dimensional spatial light modulator (diffraction grating-light modulation device 201) and diffraction grating-light modulation element 210 will be described later.

  Except for the above points, the configuration and structure of the three-dimensional image display apparatus according to the fifth embodiment can be the same as the configuration and structure of the three-dimensional image display apparatus described in the fourth embodiment. To do.

  Example 6 relates to a three-dimensional image display apparatus according to the seventh and eighth aspects of the present invention. 19, 20, 21, and 22 are conceptual diagrams of the three-dimensional image display device according to the sixth embodiment for monochrome display. In FIG. 19, the optical axis is the z axis, the orthogonal coordinates in the plane orthogonal to the z axis are the x axis and the y axis, the direction parallel to the x axis is the X direction, and the direction parallel to the y axis is Y. The direction. The X direction is, for example, the horizontal direction in the 3D image display device, and the Y direction is, for example, the vertical direction in the 3D image display device. Here, FIG. 19 is a conceptual diagram of the three-dimensional image display apparatus of Example 6 on the yz plane. The conceptual diagram of the three-dimensional image display apparatus of Example 6 in the xz plane is substantially the same as FIG. FIG. 21 is a conceptual diagram when the three-dimensional image display device of the sixth embodiment is viewed from an oblique direction, and FIG. 22 schematically shows the arrangement state of the components of the three-dimensional image display device of the sixth embodiment. FIG. 22 illustrates a transflective mirror 90 as an example.

  Even in the three-dimensional image display device 1C according to the sixth embodiment, the three-dimensional image display device alone including the components shown in FIGS. 19, 20, 21, and 22 can be compared with the conventional technology. Therefore, it is possible to generate and form a large number of light beams with high density. The three-dimensional image display device 1C according to the sixth embodiment is a single three-dimensional image display device in which a large number (M × N) of projector units 301 shown in FIG. 52 are arranged in parallel in the horizontal direction and the vertical direction. It has a function equivalent to the device. For example, when the multi-unit method is adopted, as many as the number of divided three-dimensional images, the three-dimensional image display device 1C of Embodiment 6 may be provided as shown in FIG. In FIG. 51, an apparatus provided with 4 × 4 = 16 three-dimensional image display apparatus 1C of the sixth embodiment is illustrated.

Describing along the components of the three-dimensional image display device according to the seventh aspect of the present invention, the three-dimensional image display device 1C of Example 6 is a three-dimensional image display device including a light source 10 and an optical system. It is. And this optical system
(A) a two-dimensional image forming apparatus 30 that includes a plurality of pixels 31 and generates a two-dimensional image based on light from the light source 10;
(B) An optical element 36 having an optical power for refracting incident light and condensing it at approximately one point is arranged in a two-dimensional matrix and has a function as a phase grating for modulating the phase of transmitted light. An optical device 35 that emits spatial frequencies in a two-dimensional image incident from the two-dimensional image forming device 30 along diffraction angles corresponding to a plurality of diffraction orders (total M × N);
(C) Fourier transform image forming means 40 for generating a Fourier transform image of a number corresponding to the plurality of diffraction orders (total M × N) by Fourier transforming the spatial frequency in the two-dimensional image emitted from the optical device 35. ,
(D) Fourier transform image selection means 50 for selecting a Fourier transform image corresponding to a desired diffraction order among Fourier transform images generated in a number corresponding to the plurality of diffraction orders (total M × N); and
(E) conjugate image forming means 60 for forming a conjugate image of the Fourier transform image selected by the Fourier transform image selection means 50;
It has.

Further, the conjugate image forming means 60 forms a real image of the two-dimensional image generated by the two-dimensional image forming apparatus 30 by performing inverse Fourier transform on the Fourier transform image selected by the Fourier transform image selecting means 50. Inverse Fourier transform means (specifically, a second lens L ₂ described later) is provided. Further, the Fourier transform image forming means 40 is composed of a lens, and the focal point of the optical element 36 constituting the optical device 35 (the rear focal point in the sixth embodiment) is located on the front focal plane of the lens. A Fourier transform image selection means 50 is disposed on the rear focal plane of this lens. The Fourier transform image selection means 50 has a number of openings 51 that can be controlled to be opened and closed corresponding to a plurality of diffraction orders (total M × N).

  Here, the spatial frequency in the two-dimensional image corresponds to image information using the spatial frequency of the pixel structure in the two-dimensional image forming apparatus 30 as the carrier frequency.

Further, the three-dimensional image display apparatus 1C according to the sixth embodiment will be described along the components of the three-dimensional image display apparatus according to the eighth aspect of the present invention. It is a display device. And this optical system
(A) a two-dimensional image forming apparatus 30 that has a plurality (P × Q) of pixels 31 and generates a two-dimensional image based on light from the light source 10;
(B) P _OD × Q _OD optical elements 36 having an optical power that refracts incident light and collects the light at approximately one point in a two-dimensional matrix along the X and Y directions (where P _OD and Q _OD is an arbitrary positive integer) array and has a function as a phase grating that modulates the phase of transmitted light. A spatial frequency in an incident two-dimensional image is expressed by a plurality of diffraction orders (total M × N). ) An optical device 35 that emits along a diffraction angle corresponding to
(C) The first lens (more specifically, the embodiment) in which the focal point of the optical element 36 constituting the optical device 35 (the rear focal point in the sixth embodiment) is located on the front focal plane. 6 is a convex lens) L ₁ ,
(D) M × N open / close controllable openings 51 are arranged on the rear focal plane of the first lens L _{1 and} are M along the X direction and N along the Y direction. A spatial filter SF,
(E) a second lens (more specifically, a convex lens in Example 6) L ₂ in which the spatial filter SF is disposed on the front focal plane thereof, and
(F) a third lens (more specifically, a convex lens in Example 6) L ₃ whose front focal point is located at the rear focal point of the second lens L ₂ ;
It has.

Here, in Example 6 or Example 7 or Example 12 to be described later, in the optical device 35, there are M groups (however, m and m) from the m-th order to the m′-th order along the X direction. 'Is an integer, M is a positive integer), and N sets from the n-th to the n'-th along the Y direction (where n and n' are integers and N is a positive integer) In total, M × N sets of diffracted light are generated. Here, P _OD = P = 1024, Q _OD = Q = 768, m = −4, m ′ = 4, M = m′−m + 1 = 9, n = −4, n ′ = 4, N = n′−n + 1 = 9. However, it is not limited to these values. When the constituent elements of the three-dimensional image display apparatus according to the seventh aspect of the present invention are compared with the constituent elements of the three-dimensional image display apparatus according to the eighth aspect of the present invention, the Fourier transform image forming means 40 is Corresponding to the lens L ₁ , the Fourier transform image selecting means 50 corresponds to the spatial filter SF, the inverse Fourier transform means corresponds to the second lens L ₁ , and the conjugate image forming means 60 corresponds to the second lens L ₂ and the _second lens L ₂ . It corresponds to the third lens L _3. Therefore, for the sake of convenience, the following description will be made based on the terms two-dimensional image forming apparatus 30, first lens L ₁ , spatial filter SF, second lens L ₁ , and third lens L ₃ .

  Similar to the first embodiment, an illumination optical system 20 for shaping light emitted from the light source 10 is disposed between the light source 10 and the two-dimensional image forming apparatus 30. The two-dimensional image forming apparatus 30 is illuminated with light (illumination light) emitted from the light source 10 and passed through the illumination optical system 20. The illumination optical system 20 will be described later.

  The two-dimensional image forming apparatus 30 has a plurality of pixels 31 arranged two-dimensionally, and each pixel 31 has an opening. Specifically, the two-dimensional image forming apparatus 30 includes P × Q pixels 31 that are two-dimensionally arranged, that is, arranged in a two-dimensional matrix along the X and Y directions. Each pixel 31 is provided with an opening.

  Similar to the first embodiment, one pixel 31 is an overlapping region of the transparent first electrode and the transparent second electrode and includes a region including a liquid crystal cell. Then, by operating the liquid crystal cell as a kind of light shutter (light valve), that is, by controlling the light transmittance of each pixel 31, the light transmittance of the light emitted from the light source 10 is controlled, As a whole, a two-dimensional image can be obtained. A rectangular opening is provided in an overlapping region between the transparent first electrode and the transparent second electrode, and a light emitted from the light source 10 passes through the opening to generate a two-dimensional image.

An optical device 35 is disposed adjacent to the rear of the two-dimensional image forming apparatus 30 (for example, in close contact with the two-dimensional image forming apparatus 30 or through a slight gap). Note that, by arranging the optical device 35 adjacent to the two-dimensional image forming apparatus 30, the influence of the diffraction phenomenon caused by the light passing through the openings of the pixels 31 constituting the two-dimensional image forming apparatus 30 can be ignored. it can. Here, in Example 6, the planar shape of the optical element 36 constituting the optical device 35 is a rectangular shape similar to the planar shape of the opening of the corresponding pixel 31, and each optical element 36 has positive optical power. It has a refractive grid element, specifically, a convex lens (focal length f ₀ ). And the optical apparatus 35 is comprised from a kind of micro lens array, and is produced from glass based on the well-known method of manufacturing a micro lens array.

The optical device 35 functions as a phase grating. That is, in the two-dimensional image generated by the two-dimensional image forming apparatus 30, the light emitted from each pixel 31 (this light can be regarded as parallel light) is two-dimensional image forming apparatus 30. Is incident on the corresponding optical element 36 in the optical device 35 arranged adjacent to. The light incident on the optical element 36 is refracted and collected at a substantially single point at the focal length f ₀ , and further proceeds backward from that point. Looking at this situation from another point of view, as shown in a conceptual diagram of FIG. 20, the optical device 35 at the rear of the distance f _0, if it were, a rectangular corresponding to the optical element 36 opening region (a kind of It can be considered that the light emitted from the optical element 36 passes through the virtual opening region 37. As a result, an equivalent phenomenon occurs when Fraunhofer diffraction occurs, and in the optical element 36 corresponding to each pixel 31 (more specifically, in the virtual opening region 37 corresponding to the optical element 36), M × N sets = 81 sets of diffracted light are generated. In other words, since the number of pixels 31 and optical elements 36 is P × Q = P _OD × Q _OD , a total of (P _OD × Q _OD × M × N) diffracted lights are generated in the optical device 35. Can also be considered. And the spatial frequency in a two-dimensional image is radiate | emitted from the optical apparatus 35 along the diffraction angle corresponding to several diffraction orders (total MxN) which arise from each optical element 36. FIG. The diffraction angle varies depending on the spatial frequency in the two-dimensional image. Although the value of the focal length f ₀ can be essentially an arbitrary value, the multiple optical elements 36 constituting the optical device 35 have the same focal length f ₀ . The light emitted from the optical element 36 propagates at an angle determined by the numerical aperture of the optical element 36, as shown in FIG. it can. Here, the arrangement pitch or size of the optical element 36 and d _0, the parallel light of a wavelength λ is, the width D of the light collected by the size d _0, the optical element 36 of focal length f _0, the
D = 2.44λ / sin (arctan (d ₀ / 2f ₀ ))
Can be expressed as From this, the optical aperture ratio can be expressed by (D ² / d ₀ ² ) by using the optical element 36, but no light loss is caused due to the decrease in the aperture ratio.

Further, the rear focal point (focal length f ₀ ) of the optical element 36 constituting the optical device 35 is located on the front focal plane (focal plane on the light source side) of the first lens L ₁ having the focal length f _1. A spatial filter SF is disposed on the rear focal plane of the first lens L ₁ (observer-side focal plane). The first lens L ₁ generates M × N = 81 Fourier transform images that are numbers corresponding to a plurality of diffraction orders, and these Fourier transform images are formed on the spatial filter SF. In FIG. 21, for convenience, 64 Fourier transform images are shown as dots.

  In the same manner as described in the first embodiment with reference to FIG. 6, the spatial filter SF is specifically capable of temporal opening / closing control for spatially and temporally filtering the Fourier transform image. Spatial filter. More specifically, the spatial filter SF has a number of openings 51 that can be controlled to open and close (specifically, M × N = 81) corresponding to a plurality of diffraction orders. In the spatial filter SF, one Fourier corresponding to a desired diffraction order is obtained by opening one desired opening 51 in synchronization with the generation timing of a two-dimensional image by the two-dimensional image forming apparatus 30. Select the conversion image. More specifically, the spatial filter SF is, for example, a transmissive liquid crystal display device or a reflective liquid crystal display device using a ferroelectric liquid crystal having M × N pixels, or a movable mirror is a two-dimensional matrix. It can be composed of a two-dimensional type MEMS including devices arranged in a shape.

As described above, specifically, the conjugate image forming unit 60 includes the second lens L ₂ and the third lens L ₃ . The second lens L ₂ having the focal length f ₂ performs the inverse Fourier transform on the Fourier transform image filtered by the spatial filter SF, thereby realizing the real image RI of the two-dimensional image generated by the two-dimensional image forming apparatus 30. Form. The third lens L ₃ having a focal length f ₃ forms a conjugate image CI of the Fourier transform image filtered by the spatial filter SF.

The second lens L ₂ is arranged on the front focal plane so that the spatial filter SF is positioned, and a real image RI of the two-dimensional image generated by the two-dimensional image forming apparatus 30 is formed on the rear focal plane. Are arranged to be. The magnification of the real image RI obtained here with respect to the two-dimensional image forming apparatus 30 can be changed by arbitrarily selecting the focal length f ₂ of the second lens L ₂ .

On the other hand, the third lens L ₃ is arranged such that its front focal plane coincides with the rear focal plane of the second lens L ₂ , and a conjugate image CI of the Fourier transform image is formed on the rear focal plane. Are arranged as follows. Here, since the rear focal plane of the third lens L ₃ is a conjugate plane of the spatial filter SF, it is generated by the two-dimensional image forming apparatus 30 from a portion corresponding to one opening 51 on the spatial filter SF. This is equivalent to the output of the two-dimensional image. The amount of light finally generated and output is an amount obtained by multiplying the number of pixels (P × Q) by a plurality of diffraction orders (specifically, M × N) transmitted through the optical system. Can be defined. Further, although the back focal plane of the third lens L ₃ conjugate image CI of the Fourier transform image is formed, in the back focal plane of the third lens L _3, orderly group of light beams are two-dimensionally It can be regarded as being placed. That is, as a whole, the projector unit 301 shown in FIG. 52 is arranged for a plurality of diffraction orders (specifically, M × N) on the rear focal plane of the third lens L ₃ . Is equivalent to

As schematically shown in FIGS. 21 and 23, the X direction can be obtained by one optical element 36 in the optical device 35 (more specifically, in the virtual opening region 37 located at the rear focal point of the optical element 36). 9 sets from the −4th order to the + 4th order along the Y direction, and 9 sets from the −4th order to the + 4′th order along the Y direction, a total of M × N sets = 81 sets of diffracted light. Generated. In FIG. 23, only the diffracted light of the 0th order light (n ₀ = 0), ± 1st order light (n ₀ = ± 1), and ± 2nd order light (n ₀ = ± 2) is shown as a representative. As shown, higher-order diffracted light is actually generated, and a stereoscopic image is finally formed based on these diffracted light. Here, all image information (information of all pixels) of the two-dimensional image generated by the two-dimensional image forming apparatus 30 is collected in the diffracted light (light beam) of each diffraction order. A plurality of light beam groups (9 × 9 = 81 light beam groups) generated by diffraction from the same pixel on the two-dimensional image forming apparatus 30 all have the same image information at the same time. In other words, in the two-dimensional image forming apparatus 30 including the transmissive liquid crystal display device having P × Q pixels 31, a two-dimensional image is generated based on the light from the light source 10, and the generated 2 The spatial frequency in the dimensional image is emitted from the optical device 35 along diffraction angles corresponding to a plurality of diffraction orders (total M × N) generated from the optical elements 36. That is, M × N types of copies of the two-dimensional image are emitted from the two-dimensional image forming apparatus 30 along diffraction angles corresponding to a plurality of diffraction orders (total M × N).

Then, the spatial frequency in the two-dimensional image in which all the image information of the two-dimensional image generated by the two-dimensional image forming apparatus 30 is aggregated is Fourier-transformed by the first lens L ₁ , and a plurality of diffraction orders (total M × The number of Fourier transform images corresponding to N) is generated, and the Fourier transform images are formed on the spatial filter SF. In the first lens L ₁ , a Fourier transform image having a spatial frequency in a two-dimensional image emitted along diffraction angles corresponding to a plurality of diffraction orders is generated. Obtainable.

Here, the wavelength of the light (illumination light) emitted from the light source 10 is λ (mm), the spatial frequency in the two-dimensional image generated by the two-dimensional image forming apparatus 30 is ν (lp / mm), and the first lens Assuming that the focal length of L ₁ is f ₁ (mm), the space on the rear focal plane of the first lens L ₁ is a space at a distance Y ₁ (mm) from the optical axis based on the above-described equation (A). Light having a frequency ν (Fourier transform image) appears.

Since the condensing state of the first lens L ₁ is the same as that schematically shown in FIG. 8, detailed description thereof is omitted.

In the first lens L _1, in order to transmit the spatial frequency in the two-dimensional image emitted along the diffraction angles corresponding to a plurality of diffraction orders, the first lens L ₁ in accordance with the diffraction order to use It is necessary to select an aperture ratio NA, and the aperture ratios of all lenses after the first lens L ₁ are required to be equal to or higher than the aperture ratio NA of the first lens L ₁ regardless of the focal length. .

The size of the opening 51 may be the same value as the value of Y ₁ in the formula (A), as described in the first embodiment. As an example, the wavelength λ of the illumination light 532 nm, and the focal length f ₁ of the first lens L ₁ 50 mm, the size of one pixel 31 in the two-dimensional image forming apparatus 30 is for approximately 13Myuemu～14myuemu, Y ₁ Value Is about 2 mm. This means that a Fourier transform image corresponding to each diffraction order can be obtained at a high density of about 2 mm on the spatial filter SF. In other words, 9 × 9 = 81 Fourier transform images can be obtained on the spatial filter SF at intervals of about 2 mm in both the X direction and the Y direction.

  Here, since the spatial frequency ν in the two-dimensional image generated by the two-dimensional image forming apparatus 30 is generated by the two-dimensional image forming apparatus 30 including the P × Q pixels 31, the two-dimensional image is generated. At most, the frequency has a period composed of two consecutive pixels 31 constituting the two-dimensional image forming apparatus 30.

A schematic front view of the two-dimensional image forming apparatus 30 in the state where the spatial frequency in the two-dimensional image generated by the two-dimensional image forming apparatus 30 is the lowest is the same as that shown in FIG. In this case, the frequency characteristic of the light intensity of the Fourier transform image formed by the first lens L ₁ is the same as that shown in FIG. On the other hand, a schematic front view of the two-dimensional image forming apparatus 30 having the highest spatial frequency in the conjugate image of the two-dimensional image is the same as that shown in FIG. The frequency characteristic of the light intensity of the Fourier transform image formed by the _first lens L ₁ is the same as that shown in FIG. Furthermore, the distribution of the Fourier transform image on the spatial filter SF (on the xy plane) is the same as shown in FIGS. 11A, 11B, and 11C. Further, the planar shape of the opening 51 in the spatial filter SF may be the same as that in the first embodiment.

By the way, the state with the highest spatial frequency is a case where all pixels alternately display black display and white display, as shown in FIG. 9B. The relationship between the spatial frequency of the pixel structure in the two-dimensional image forming apparatus 30 and the spatial frequency in the two-dimensional image is as follows. That is, when it is assumed that the aperture occupies all the pixels (that is, the aperture ratio is 100%), the highest spatial frequency in the two-dimensional image is (1/2) of the spatial frequency of the pixel structure. Also, if the aperture occupies a certain percentage of pixels (less than 100%), the highest spatial frequency in the two-dimensional image is below (1/2) of the spatial frequency of the pixel structure. Therefore, all the spatial frequencies in the two-dimensional image appear up to the half of the periodic pattern interval due to the pixel structure appearing in the spatial filter SF. For this reason, all the openings 51 can be arranged without spatially interfering with each other. That is, for example, the (3,2) th aperture 51, while the Fourier transform image having a diffraction order of _{m 0 = 3, n 0 =} 2 enters, the _{m 0 = 3, n 0 =} 2 The Fourier transform image having the diffraction order does not enter the other openings 51. As a result, the space in the two-dimensional image generated by the two-dimensional image forming apparatus 30 in the Fourier transform image located in one opening 51 on the spatial filter SF having the independent opening 51 for each Fourier transform image. While the frequency exists, the spatial frequency in the two-dimensional image generated by the two-dimensional image forming apparatus 30 is not lost due to the spatial restriction of the opening 51. The spatial frequency of the pixel structure can be regarded as the carrier frequency, and the spatial frequency in the two-dimensional image corresponds to image information using the spatial frequency of the pixel structure as the carrier frequency.

  In the spatial filter SF, the opening / closing control of the opening 51 is performed in order to control the passage / non-passage of the M × N Fourier transform images. If the spatial filter SF is composed of, for example, a liquid crystal display device, the opening / closing control of the opening 51 can be performed by operating the liquid crystal cell as a kind of light shutter (light valve).

When the brightness of the obtained image is different depending on the diffraction order, as described above, a neutral density filter for dimming a bright image with the darkest image as a reference is used for the third lens L ₃ . What is necessary is just to arrange | position to a back side focal plane. The same applies to Example 7 and Example 12 described later.

As described above, according to the three-dimensional image display device 1C of the sixth embodiment, the spatial frequency in the two-dimensional image generated by the two-dimensional image forming device 30 is along the diffraction angles corresponding to a plurality of diffraction orders. The Fourier transform image obtained by the Fourier transform by the Fourier transform image forming means 40 (first lens L ₁ ) is spatially and Fourier transformed by the Fourier transform image selection means 50 (spatial filter SF). In addition, since it has a configuration in which a conjugate image CI of the filtered Fourier transform image is formed by temporal filtering, a plurality of three-dimensional image display devices can be spatially high in density without increasing the size of the entire three-dimensional image display device. A group of rays can be generated and scattered in a state distributed in the direction of. In addition, each light beam that is a constituent element of the light beam group can be independently controlled temporally and spatially. As a result, it is possible to obtain a three-dimensional image using light rays that are close to the same quality as real-world objects.

  Further, according to the three-dimensional image display apparatus 1C of the sixth embodiment, since the light beam reproduction method is used, it is possible to provide a stereoscopic image that satisfies visual functions such as focus adjustment, convergence, and motion parallax. . Furthermore, according to the three-dimensional image display apparatus 1C of the sixth embodiment, since higher-order diffracted light is efficiently used, one image output device (two-dimensional image formation) is compared with the conventional image output method. Light rays (a kind of copy of a two-dimensional image) that can be controlled by the device 30 and the optical device 35) can be obtained for a plurality of diffraction orders (ie M × N). In addition, according to the 3D image display apparatus 1C of the sixth embodiment, spatial and temporal filtering is performed, so that the temporal characteristics of the 3D image display apparatus are changed to the spatial characteristics of the 3D image display apparatus. Can be converted. In addition, a stereoscopic image can be obtained without using a diffusion screen or the like. Furthermore, it is possible to provide an appropriate stereoscopic image for observation from any direction. In addition, since a group of rays can be generated and scattered at a spatially high density, a fine spatial image close to the visual recognition limit can be provided.

  The seventh embodiment is a modification of the sixth embodiment. A conceptual diagram of the three-dimensional image display apparatus of Example 7 is shown in FIG. In FIG. 24, a semi-transmissive mirror 90 is illustrated.

The two-dimensional image forming apparatus 130 according to the seventh embodiment is different from the liquid crystal display apparatus according to the sixth embodiment in that a one-dimensional image forming apparatus (specifically, one-dimensional image forming apparatus that generates P (for example, 1920) partitioned one-dimensional images). Is generated by a diffraction grating-light modulation device 201); and a one-dimensional image forming device (diffraction grating-light modulation device 201), and two-dimensionally developing (scanning) a P-partitioned one-dimensional image. And a scanning optical system (specifically, a scan mirror 205) that forms a two-dimensional image divided into P × Q. An optical device 35 is disposed behind the scanning optical system. The spatial frequency in the generated two-dimensional image is arranged along the diffraction angle corresponding to a plurality of diffraction orders (specifically, the total number M ₀ × N ₀ ). Emitted.

The conceptual diagram of the two-dimensional image forming apparatus 130 including the diffraction grating-light modulation apparatus is the same as the light modulation means 130 of the third embodiment shown in FIG. The two-dimensional image obtained by scanning passes through the scanning lens system 131 and enters the optical device 35 arranged on the generation surface of the two-dimensional image, and is divided into P × Q pieces in the optical device 35. For each section of the two-dimensional image, M × N sets of diffracted light are generated. Specifically, the spatial frequency in the generated two-dimensional image is emitted from the optical device 35 along diffraction angles corresponding to a plurality of diffraction orders generated from the optical elements 36 of the optical device 35. The rear focal point of the optical device 35 is disposed on the front focal plane of the first lens L ₁ having the focal length f ₁ . The one-dimensional spatial light modulator (diffraction grating-light modulation device 201) and diffraction grating-light modulation element 210 will be described later.

  Except for the above points, the configuration and structure of the three-dimensional image display apparatus according to the seventh embodiment can be the same as the configuration and structure of the three-dimensional image display apparatus described in the sixth embodiment. To do.

Example 8 relates to a three-dimensional image display apparatus according to the ninth and tenth aspects of the present invention. FIG. 25, FIG. 26 and FIG. 27 show conceptual diagrams of a three-dimensional image display apparatus according to the eighth embodiment for monochrome display. Here, FIG. 25 is a conceptual diagram of the three-dimensional image display apparatus according to the eighth embodiment in the xz plane and the x′z ′ plane. The conceptual diagram of the three-dimensional image display apparatus according to the eighth embodiment in the yz plane and the y′z ′ plane is substantially the same except for the arrangement of the imaging means 82 (third lens L ₃ ) and the beam splitter 81 described later. This is the same as FIG. FIG. 26 is a conceptual diagram when the three-dimensional image display device of the eighth embodiment is viewed from an oblique direction, and FIG. 27 schematically shows the arrangement state of the components of the three-dimensional image display device of the eighth embodiment. FIG. 27 illustrates a transflective mirror 90 as an example. In FIG. 26, most of the components of the three-dimensional image display device are omitted, and the illustration of light rays is simplified, which is different from FIGS. 25 and 27. Furthermore, in FIG. 26, only a part of the light beam emitted from the two-dimensional image forming apparatus is illustrated.

Even in the three-dimensional image display device 1D according to the eighth embodiment, the three-dimensional image display device alone including the components shown in FIGS. 25, 26, and 27 has a spatial density as compared with the conventional technique. And it is possible to generate and form a large number of light beams. The three-dimensional image display apparatus 1D according to the eighth embodiment is a single three-dimensional image display apparatus, and a large number (S ₀ × T ₀ pieces) of projector units 301 shown in FIG. 52 are arranged in parallel in the horizontal direction and the vertical direction. It has a function equivalent to the arranged device. For example, when the multi-unit system is adopted, the three-dimensional image display device 1D according to the eighth embodiment may be provided as many as the number of divided three-dimensional images (for example, 4 × 4 = 16).

Describing along the components of the three-dimensional image display device according to the ninth aspect of the present invention, the three-dimensional image display device 1D of Example 8 is a three-dimensional image display device including a light source 10 and an optical system. It is. And this optical system
(A) A plurality of pixels 31 are provided, light from the light source 10 is modulated by each pixel 31 to generate a two-dimensional image, and a spatial frequency in the generated two-dimensional image is generated from the plurality of pixels 31. Light modulating means 30 for emitting along a diffraction angle corresponding to the diffraction order;
(B) Fourier transform of the spatial frequency in the two-dimensional image emitted from the light modulation means 30 to generate a number of Fourier transform images corresponding to a plurality of diffraction orders generated from the respective pixels 31, and these Fourier transform images Only a predetermined Fourier transform image (for example, a Fourier transform image corresponding to the first order diffraction using the 0th order diffraction of the plane wave component as the carrier frequency) is selected, and the selected Fourier transform image is further converted to the inverse Fourier. An image limiting / generating unit 32 that converts and forms a conjugate image of the two-dimensional image generated by the light modulation unit 30 (a real image of the two-dimensional image);
(C) a light beam traveling direction changing unit 80 that changes (changes) the traveling direction of the light beam emitted from the image limiting / generating unit; and
(D) Imaging means 82 for forming an image of the light beam emitted from the light beam traveling direction changing means 80;
It has.

  Here, the spatial frequency in the two-dimensional image corresponds to image information using the spatial frequency of the pixel structure as the carrier frequency. The spatial frequency in the conjugate image of the two-dimensional image is a spatial frequency obtained by removing the spatial frequency of the pixel structure from the spatial frequency in the two-dimensional image.

Then, the image restriction / generation unit 32
(B-1) The first lens L ₁ that generates a Fourier transform image having a number corresponding to a plurality of diffraction orders generated from each pixel by Fourier transforming the spatial frequency in the two-dimensional image emitted from the light modulation means 30. ,
(B-2) It is arranged closer to the light beam traveling direction changing means side than the first lens L ₁ , and a predetermined Fourier transform image (for example, 0th-order diffraction of a plane wave component is used as a carrier frequency among these Fourier transform images) A scattering diffraction limiting aperture (image limiting aperture) 33 for selecting only the Fourier transform image corresponding to the first order diffraction), and
(B-3) A conjugate of the two-dimensional image generated by the light modulation means 30 by being arranged on the light beam traveling direction changing means side with respect to the scattering diffraction limiting aperture 33 and performing inverse Fourier transform on the selected Fourier transform image. A second lens L ₂ forming an image,
It is composed of The scattering diffraction limiting aperture 33 is disposed on the rear focal plane of the first lens L ₁ and on the front focal plane of the second lens L ₂ . The same applies to Example 9 and Example 12 described later.

Further, the three-dimensional image display device 1D according to the eighth embodiment will be described along the components of the three-dimensional image display device according to the tenth aspect of the present invention. It is a display device. And this optical system
(A) It has openings (number: P ₀ × Q ₀ ) arranged in a two-dimensional matrix along the X and Y directions, and controls the passage, reflection, or diffraction of light from the light source 10 for each opening. A two-dimensional image forming apparatus 30 for generating a two-dimensional image and generating diffracted light of a plurality of diffraction orders for each aperture based on the two-dimensional image
(B) a first lens L ₁ in which a two-dimensional image forming apparatus 30 is disposed on the front focal plane;
(C) Only the diffracted light of a predetermined diffraction order (for example, a Fourier transform image corresponding to the first order diffraction using the 0th order diffraction of the plane wave component as the carrier frequency) disposed on the rear focal plane of the first lens L ₁ is used. A scattering diffraction limiting aperture (image limiting aperture) 33 to be passed;
(D) a second lens L ₂ in which a scattering diffraction limiting aperture 33 is arranged on the front focal plane;
(E) is arranged in the second lens L ₂ of the rear (rear side focal plane), to change the traveling direction of the light ray emitted from the second lens L ₂ (alters) light ray traveling direction change means 80, and ,
(F) a third lens L ₃ for forming an image of the light beam emitted from the light beam traveling direction changing means 80;
It has.

In Example 8, the first lens L ₁ , the second lens L ₂ , and the third lens L ₃ are specifically composed of convex lenses.

Here, in Example 8 or Example 9 or Example 12 described later, P ₀ = 1024, Q ₀ = 768, S ₀ = 8, and T ₀ = 8. However, it is not limited to these values. Further, the z-axis, which is the optical axis portion up to the light beam traveling direction changing means 80, extends to the light beam traveling direction changing means 80 constituting the three-dimensional image display device 1D of the ninth embodiment or the twelfth embodiment described later. Through the center of each of the components, and is orthogonal to these components constituting the three-dimensional image display device 1D. When the components of the three-dimensional image display device according to the ninth aspect of the present invention are compared with the components of the three-dimensional image display device according to the tenth or eleventh aspect of the present invention, the light modulation means 30 is Corresponding to the two-dimensional image forming apparatus 30, the image limiting / generating unit 32 corresponds to the first lens L ₁ , the scattering diffraction limiting aperture (image limiting aperture) 33, and the second lens L ₂ , and forms an image. The means 82 corresponds to the third lens L ₃ . Therefore, for the sake of convenience, the following description will be given based on the terms two-dimensional image forming apparatus 30, first lens L ₁ , scattering diffraction limiting aperture 33, second lens L ₂ , and third lens L ₃ .

  Similar to the first embodiment, an illumination optical system 20 for shaping light emitted from the light source 10 is disposed between the light source 10 and the two-dimensional image forming apparatus 30. The two-dimensional image forming apparatus 30 is illuminated with light (illumination light) emitted from the light source 10 and passed through the illumination optical system 20. The illumination optical system 20 will be described later.

The two-dimensional image forming apparatus 30 includes a two-dimensional spatial light modulator having a plurality of pixels 31 arranged two-dimensionally, and each pixel 31 has an opening. Specifically, the two-dimensional image forming device 30 or the two-dimensional spatial light modulator is two-dimensionally arranged, that is, P ₀ × arranged in a two-dimensional matrix along the X direction and the Y direction. It consists of a transmissive liquid crystal display device having Q ₀ pixels 31, and each pixel 31 is provided with an opening.

Similar to the first embodiment, one pixel 31 is an overlapping region of the transparent first electrode and the transparent second electrode and includes a region including a liquid crystal cell. Then, by operating the liquid crystal cell as a kind of light shutter (light valve), that is, by controlling the light transmittance of each pixel 31, the light transmittance of the light emitted from the light source 10 is controlled, As a whole, a two-dimensional image can be obtained. In the overlapping region of the transparent first electrode and the transparent second electrode, a rectangular opening is provided. When light emitted from the light source 10 passes through the opening, Fraunhofer diffraction occurs. ₀ × N ₀ diffracted light is generated. In other words, since the number of pixels 31 is P ₀ × Q ₀ , it can be considered that a total of (P ₀ × Q ₀ × M ₀ × N ₀ ) diffracted lights are generated. In the two-dimensional image forming apparatus 30, the spatial frequency in the two-dimensional image is emitted from the two-dimensional image forming apparatus 30 along diffraction angles corresponding to a plurality of diffraction orders (total M ₀ × N ₀ ) generated from each pixel 31. Is done. The diffraction angle varies depending on the spatial frequency in the two-dimensional image.

A two-dimensional image forming apparatus 30 is arranged on the front focal plane (focal plane on the light source side) of the first lens L ₁ having a focal length f _1, and the rear focal plane (observation) of the first lens L _1. Scattering diffraction limiting aperture 33 is arranged on the focal plane on the person side. A number of Fourier transform images corresponding to a plurality of diffraction orders are generated by the first lens L ₁ , and these Fourier transform images are formed in a plane where the scattering diffraction limiting aperture 33 is located. Then, only diffracted light of a predetermined diffraction order (for example, a Fourier transform image corresponding to the first order diffraction using the 0th order diffraction of the plane wave component as the carrier frequency) passes through the scattering diffraction limiting opening 33. A scattering diffraction limiting aperture 33 is disposed on the front focal plane of the second lens L ₂ having the focal length f ₂ . Furthermore, the light beam traveling direction changing means 80 is disposed on the rear focal plane of the second lens L ₂ and on the front focal plane of the third lens L ₃ having the focal length f ₃ . . The rear focal plane of the third lens L ₃ corresponds to the imaging plane IS. A beam splitter 81 is disposed between the second lens L ₂ and the light beam traveling direction changing means 80, and the light beam from the _second lens L ₂ passes through the beam splitter 81 and travels. It enters the direction changing means 80.

The light beam traveling direction changing means 80 is constituted by a reflective optical means that can change (change) the angle of the emitted light with respect to the incident light, specifically, a mirror, for example. More specifically, the mirror is composed of a polygon mirror. By controlling the tilt angle of the rotation axis while rotating the polygon mirror around the rotation axis, the image is formed on the imaging plane IS. The positions where the images are formed can be positions arranged in a two-dimensional matrix of S ₀ × T ₀ locations.

  The light beam traveling direction changing means 80 is constituted by a transmission type optical means capable of changing (changing) the angle of the emitted light with respect to the incident light, specifically, for example, a prism. Can do. In this case, for example, a mechanism for rotating (changing) the prism in a desired direction about the z axis may be provided.

The third lens L ₃ is arranged so that its front focal plane coincides with the rear focal plane of the second lens L ₂ , and a conjugate image CI of the Fourier transform image is formed on the rear focal plane (imaging plane IS). Are arranged to form. The light beam reflected by the light beam traveling direction changing means 80 is reflected by the beam splitter 81 and enters the _third lens L ₃ . Here, since the rear focal plane of the third lens L ₃ is a conjugate plane of the scattering diffraction limiting aperture 33, a conjugate image of a two-dimensional image is output from the scattering diffraction limiting aperture 33 ( However, the final direction component of the conjugate image of the two-dimensional image is equivalent to that defined by the light beam traveling direction changing means 80). The amount of light finally generated / output is the number of pixels (P ₀ × Q ₀ ), and is the light that has passed through the scattering diffraction limiting aperture 33. That is, the amount of light passing through the scattering diffraction limiting aperture 33 is not substantially reduced by passing and reflecting the subsequent components of the three-dimensional image display device. Further, since the back focal plane of the third lens L ₂ conjugate image CI of the Fourier transform image is formed, the direction component of the conjugate image of the two-dimensional image defined by the light ray traveling direction change means 80, In the rear focal plane of the third lens L ₃ , it can be considered that the light beam groups are arranged two-dimensionally and orderly. That is, as a whole, a plurality of projector units 301 shown in FIG. 52 (specifically, S ₀ × T ₀ ) are provided on the rear focal plane (imaging plane IS) of the third lens L ₃ . Is equivalent to the state of being arranged. In the following description, the light beam emitted from the light beam traveling direction changing unit 80 is connected to the (m, n) th position on the rear focal plane (imaging plane IS) of the third lens L _3. When imaged, such imaging may be referred to as the (m, n) th imaging. In FIG. 26, for convenience, 64 images are shown as dots.

As schematically shown in FIG. 7, a single pixel 31 in the two-dimensional image forming apparatus 30 generates a total of M ₀ × N ₀ sets of diffracted light along the X and Y directions. In FIG. 7, only the diffracted light of the 0th order light (n ₀ = 0), ± 1st order light (n ₀ = ± 1), and ± 2nd order light (n ₀ = ± 2) is shown as a representative. However, actually, higher-order diffracted light is generated, and a stereoscopic image is finally formed based on a part of the diffracted light. Here, all image information (information of all pixels) of the two-dimensional image generated by the two-dimensional image forming apparatus 30 is collected in the diffracted light (light beam) of each diffraction order. A plurality of light ray groups generated by diffraction from the same pixel on the two-dimensional image forming apparatus 30 all have the same image information at the same time. In other words, in the two-dimensional image forming apparatus 30 composed of a transmissive liquid crystal display device having P ₀ × Q ₀ pixels 31, the light from the light source 10 is modulated by each pixel 31 to generate a two-dimensional image. It is, and the spatial frequency in the generated two-dimensional image is emitted along diffraction angles corresponding to a plurality of diffraction orders (total M ₀ × N ₀₎ generated from the respective pixels 31. That is, a kind of M ₀ × N ₀ copies of the two-dimensional image are emitted from the two-dimensional image forming apparatus 30 along diffraction angles corresponding to a plurality of diffraction orders (total M ₀ × N ₀ ).

Then, the spatial frequency in the two-dimensional image emitted from the two-dimensional image forming apparatus 30 is Fourier-transformed by the first lens L ₁ , and a number of Fourier-transform images corresponding to a plurality of diffraction orders generated from each pixel 31 are generated. Is done. Of these Fourier transform images, only a predetermined Fourier transform image (for example, a Fourier transform image corresponding to the first order diffraction using the zeroth order diffraction of the plane wave component as the carrier frequency) passes through the scattering diffraction limiting aperture 33. Further, the selected Fourier transform image is subjected to inverse Fourier transform by the second lens L ₂ to form a conjugate image of the two-dimensional image generated by the two-dimensional image forming apparatus 30, and the conjugate of the two-dimensional image. The image is incident on the light beam traveling direction changing means 80. Note that the spatial frequency in the two-dimensional image corresponds to image information in which the spatial frequency of the pixel structure is a carrier frequency, but only in a region of image information having a 0th-order plane wave as a carrier wave (that is, the maximum spatial frequency of the pixel structure). In other words, it is obtained as first-order diffraction using the 0th-order diffraction of the plane wave component as the carrier frequency, and the spatial frequency of the pixel structure (aperture structure) of the light modulation means Less than half of the spatial frequency passes through the scattering diffraction limiting aperture 33. Thus, the conjugate image of the two-dimensional image formed on the light beam traveling direction changing unit 80 does not include the pixel structure of the two-dimensional image forming apparatus 30, but is generated by the two-dimensional image forming apparatus 30. All of the spatial frequencies in the two-dimensional image are included.

The spatial frequency in the conjugate image of the two-dimensional image in which all the image information of the two-dimensional image generated by the two-dimensional image forming apparatus 30 is aggregated is emitted in a state where the direction component is changed from the light beam traveling direction changing unit 80, An image is formed on the imaging plane IS by the third lens L ₃ . In the third lens L ₃ , a Fourier transform image having a spatial frequency in the conjugate image of the two-dimensional image emitted from the light beam traveling direction changing means 80 is generated, so that a Fourier transform image can be obtained with a spatially high density. Can do.

  As described above, according to the three-dimensional image display apparatus 1D of the eighth embodiment, the spatial frequency in the two-dimensional image generated by the light modulation unit (two-dimensional image forming apparatus) 30 is changed by the light beam traveling direction changing unit 80. Is emitted along a predetermined angle, and the conjugate image CI is imaged on the imaging plane IS. Therefore, the entire three-dimensional image display device is enlarged without increasing the size, and A group of rays can be generated and scattered in a state distributed in a plurality of directions. Further, by providing the light beam traveling direction changing means 80, the contrast of the obtained image is not lowered, and a clear and blur-free stereoscopic image can be observed. In addition, each light beam that is a constituent element of the light beam group can be independently and temporally controlled. As a result, it is possible to obtain a three-dimensional image using light rays that are close to the same quality as real-world objects.

  Further, according to the three-dimensional image display apparatus 1D of the eighth embodiment, since the light beam reproduction method is used, it is possible to provide a stereoscopic image that satisfies visual functions such as focus adjustment, convergence, and motion parallax. . Furthermore, according to the three-dimensional image display device 1D of the eighth embodiment, the direction component of the image is controlled by the light beam traveling direction changing means 80. Moreover, according to the three-dimensional image display device 1D of the eighth embodiment, Since the beam traveling direction changing means 80 performs a kind of filtering spatially and temporally, the temporal characteristic of the three-dimensional image display device can be converted into the spatial characteristic of the three-dimensional image display device. In addition, a stereoscopic image can be obtained without using a diffusion screen or the like. Furthermore, it is possible to provide an appropriate stereoscopic image for observation from any direction. In addition, since a group of rays can be generated and scattered at a spatially high density, a fine spatial image close to the visual recognition limit can be provided.

  Example 9 relates to a three-dimensional image display device according to the ninth and eleventh aspects of the present invention. FIG. 28 shows a conceptual diagram of the three-dimensional image display apparatus according to the ninth embodiment. In FIG. 28, a transflective mirror 90 is illustrated.

Unlike the liquid crystal display device according to the eighth embodiment, the light modulating unit 130 according to the ninth embodiment is a one-dimensional spatial light modulator that generates a one-dimensional image divided into P ₀ (eg, 1920) (specifically, Is generated by a one-dimensional spatial light modulator (diffraction grating-light modulation device 201), and two-dimensionally develops (scans) the one-dimensional image divided into P ₀ pieces. A scanning optical system (specifically, a scan mirror 205) that generates a two-dimensional image divided into P ₀ × Q ₀ ; and a two-dimensional image that is arranged and generated on the generation surface of the two-dimensional image A grating filter (diffraction grating filter) 132 that emits spatial frequencies in an image along diffraction angles corresponding to a plurality of diffraction orders (specifically, total number M ₀ × N ₀ ) is provided. Here, M ₀ × N ₀ sets of diffracted light are generated by the grating filter 132 for each section of the two-dimensional image formed by the scanning optical system (scan mirror 205) and partitioned into P ₀ × Q ₀ pieces. . The grating filter 132 may be composed of an amplitude grating or a phase grating.

Alternatively, the three-dimensional image display apparatus according to the ninth embodiment will be described along the components of the three-dimensional image display apparatus according to the eleventh aspect of the present invention. It is a display device. And this optical system
(A) A one-dimensional spatial light modulator that generates a one-dimensional image (specifically, a diffraction grating light modulator 201); two-dimensionally develops the one-dimensional image generated by the one-dimensional spatial light modulator. A scanning optical system that generates a two-dimensional image (specifically, a scan mirror 205); A two-dimensional image forming apparatus 130 comprising means (specifically, a lattice filter 132),
(B) a first lens L ₁ in which diffracted light generating means (grating filter 132) is disposed on the front focal plane;
(C) Only the diffracted light of a predetermined diffraction order (for example, a Fourier transform image corresponding to the first order diffraction using the 0th order diffraction of the plane wave component as the carrier frequency) is disposed on the rear focal plane of the first lens L _1. A scattering diffraction limiting aperture 33 to be passed,
(D) a second lens L ₂ in which a scattering diffraction limiting aperture 33 is arranged on the front focal plane;
(E) is arranged behind the second lens L _2, the second lens L ₂ to change the traveling direction of a light ray emitted from the (changing) light ray traveling direction change means 80, and,
(F) a third lens L ₃ for forming an image of the light beam emitted from the light beam traveling direction changing means 80;
It has.

The conceptual diagram of the two-dimensional image forming apparatus 130 including the diffraction grating-light modulation device is the same as the light modulation means 130 of the third embodiment shown in FIG. , M ₀ × N ₀ sets of diffracted light are generated for each section of the two-dimensional image partitioned into P ₀ × Q ₀ pieces.

  Except for the above points, the configuration and structure of the three-dimensional image display apparatus according to the ninth embodiment can be the same as the configuration and structure of the three-dimensional image display apparatus described in the eighth embodiment. To do.

  Example 10 relates to a three-dimensional image display apparatus according to the twelfth and thirteenth aspects of the present invention. FIG. 29 is a conceptual diagram of the three-dimensional image display apparatus according to the tenth embodiment for monochrome display. In FIG. 29, the optical axis is the z axis, the orthogonal coordinates in the plane orthogonal to the z axis are the x axis and the y axis, the direction parallel to the x axis is the X direction, and the direction parallel to the y axis is Y. The direction. The X direction is, for example, the horizontal direction in the 3D image display device, and the Y direction is, for example, the vertical direction in the 3D image display device. Here, FIG. 29 is a conceptual diagram of the three-dimensional image display apparatus of Example 10 on the yz plane. The conceptual diagram of the three-dimensional image display apparatus of Example 10 in the xz plane is substantially the same as FIG. Further, the conceptual diagram when the three-dimensional image display device of Example 10 is viewed obliquely is the same as that shown in FIG. 4, and FIG. 30 shows the arrangement state of the components of the three-dimensional image display device of Example 10. FIG. 30 illustrates a transflective mirror 90 as an example. Further, FIGS. 31 and 32 are conceptual diagrams in which the vicinity of the light modulation means (two-dimensional image forming apparatus), the Fourier transform image forming means (first lens), and the Fourier transform image selecting means (spatial filter) are enlarged. (A) and (B). Furthermore, a schematic front view of the light source is shown in FIG. 33, and a schematic front view of the spatial filter is shown in FIG.

Even in the 3D image display device 1E of Example 10, the 3D image display device alone having the components shown in FIG. 29 and the like is spatially higher in density than the conventional technology, and A large number of light beams can be generated and formed. The three-dimensional image display apparatus 1E according to the tenth embodiment is a single three-dimensional image display apparatus, and a large number (U ₀ × V ₀ pieces) of projector units 301 shown in FIG. 52 are arranged in parallel in the horizontal direction and the vertical direction. It has a function equivalent to the arranged device. For example, when the multi-unit method is adopted, as shown in the conceptual diagram of FIG. 51, the number of divided three-dimensional images (for example, 4 × 4 = 16) is the three-dimensional image display of the tenth embodiment. What is necessary is just to provide the apparatus 1E.

Describing along the constituent elements of the three-dimensional image display device according to the twelfth aspect of the present invention, the three-dimensional image display device 1E of Example 10 emits light from a plurality of discrete light emission positions. A three-dimensional image display device including a light source 10E and an optical system. And this optical system
(A) A two-dimensional image having a plurality of pixels (number: P × Q) 31, which are sequentially emitted from different light emission positions of the light source 10 </ b> E and having different incident directions (illumination light) by the pixels 31. And a light modulation means 30 that emits the spatial frequency in the generated two-dimensional image along diffraction angles corresponding to a plurality of diffraction orders (total M × N) generated from each pixel 31, and
(B) Fourier transform of the spatial frequency in the two-dimensional image emitted from the light modulation means 30 to generate a number of Fourier transform images corresponding to the plurality of diffraction orders (total M × N). Fourier transform image forming means 40 for imaging
In addition,
(C) conjugate image forming means 60 for forming a conjugate image of the Fourier transform image formed by the Fourier transform image forming means 40;
It has.

Alternatively, to explain along the components of the three-dimensional image display device according to the thirteenth aspect of the present invention, the three-dimensional image display device 1E of the tenth embodiment is based on a plurality of discrete light output positions. This is a three-dimensional image display device including a light source 10E that emits light and an optical system. And this optical system
(A) Light (illumination) having openings (number: P × Q) arranged in a two-dimensional matrix along the X and Y directions, sequentially emitted from different light emission positions of the light source 10E, and having different incident directions A two-dimensional image that generates a two-dimensional image by controlling the passage of light) for each aperture, and that generates diffracted light of a plurality of diffraction orders (total M × N) for each aperture based on the two-dimensional image. Image forming apparatus 30,
(B) a first lens L ₁ in which a two-dimensional image forming apparatus 30 is disposed on the front focal plane (focal plane on the light source side);
(C) on the rear focal plane of the first lens L ₁ (the focal surface on the observer side), a front-side focal plane the second lens (the focal plane of the light source side) is positioned L _2, and,
(D) a third lens L ₃ whose front focal plane is located on the rear focal plane of the second lens L ₂ ;
It has.

  Here, the spatial frequency in the two-dimensional image corresponds to image information using the spatial frequency of the pixel structure as the carrier frequency.

In the three-dimensional image display device 1E according to the tenth embodiment, the light source 10E is the light emitting element 11 and the light emitted from the light emitting element 11 and incident on the light modulating unit or the two-dimensional image forming apparatus 30. A light beam traveling direction changing means for changing the direction is provided. Here, a plurality of light emitting elements 11 (specifically, light emitting diodes) are provided, and the plurality of light emitting elements 11 are arranged in a two-dimensional matrix. Note that the number of the plurality of light emitting elements 11 arranged in a two-dimensional matrix is U ₀ '× V ₀ ', and the number of discrete light emission positions in the light source 10E is U ₀ × V ₀ ( However, U ₀ = U ₀ ′, V ₀ = V ₀ ′). In the tenth embodiment, P = 1024, Q = 768, U ₀ = 9, and V ₀ = 9. However, it is not limited to these values. Further, the light beam traveling direction changing means is composed of a refractive optical means, specifically a lens, more specifically a collimator lens 12. Here, a plurality of light emitting elements 11 are disposed in the vicinity of the front focal plane of the collimator lens 12, and are emitted from each light emitting element 11, incident on the collimator lens 12, and light (parallel light) emitted from the collimator lens 12. ) Can be three-dimensionally changed by the collimator lens 12, so that the incident direction of light (illumination light) incident on the light modulation means or the two-dimensional image forming apparatus 30 can be three-dimensionally changed (FIG. 31). In addition, although the emission direction of the light emitted from each light emitting element 11 is the same in the tenth embodiment (specifically, parallel to the optical axis), it may be different. Alternatively, in other words, a lens (specifically, a collimator lens 12) is arranged between the light emitting elements 11 serving as the light source and the light modulation means or the two-dimensional image forming apparatus 30. The light emitting element 11 is located in the front focal plane of the collimator lens 12 or in the vicinity of the front focal plane.

When the constituent elements of the three-dimensional image display apparatus according to the twelfth aspect of the present invention are compared with the constituent elements of the three-dimensional image display apparatus according to the thirteenth aspect of the present invention, the light modulation means 30 is the two-dimensional image forming apparatus. 30, the Fourier transform image forming means 40 corresponds to the first lens L ₁ , the Fourier transform image selection means 50 described later corresponds to the spatial filter SF, and the inverse Fourier transform means corresponds to the second lens L ₂ . Correspondingly, the conjugate image forming means 60 corresponds to the second lens L ₂ and the third lens L ₃ . Therefore, for the sake of convenience, the following description will be given based on the terms two-dimensional image forming apparatus 30, first lens L ₁ , spatial filter SF, second lens L ₂ , and third lens L ₃ .

_{A state} in which light beams emitted from the light emitting elements 11 _A , 11 _B , and 11 _C constituting the light source 10E pass through the two-dimensional image forming apparatus 30, the first lens L ₁ , and the spatial filter SF is schematically illustrated. As shown in FIG. In Figure 31 shows the light beam emitted from the light emitting element 11 _A constituting the light source 10E by the solid line, the light flux emitted from the light emitting element 11 _B shown by a one-dot chain line, dotted light flux emitted from the light emitting element 11 _C It shows with. In addition, the positions of the images in the spatial filter SF formed by the illumination light emitted from the light emitting elements 11 _A , 11 _B , and 11 _C are denoted by reference numerals (11 _A ), (11 _B ), and (11 _C ), respectively. . Note that the position numbers (which will be described later) of the light emitting elements 11 _A , 11 _B , 11 _C constituting the light source 10E are, for example, the (4,0) th, (0,0) th, and , (−4,0) th. Here, when a certain light emitting element is in a light emitting state, all other light emitting elements are turned off.

  As described above, the collimator lens 12 is disposed between the light emitting element 11 and the two-dimensional image forming apparatus 30. The two-dimensional image forming apparatus 30 is illuminated by the illumination light emitted from the light emitting element 11 and passed through the collimator lens 12. As described above, the incident direction of the illumination light to the two-dimensional image forming apparatus 30 is as follows. Depending on the two-dimensional position (light emission position) of the light emitting element 11, the light emitting element 11 is three-dimensionally different.

  The light modulation means 30 includes a two-dimensional spatial light modulator having a plurality of pixels 31 arranged two-dimensionally, and each pixel 31 has an opening. Here, the two-dimensional spatial light modulator or the two-dimensional image forming apparatus 30 is specifically arranged two-dimensionally, that is, arranged in a two-dimensional matrix along the X and Y directions. It consists of a transmissive liquid crystal display device having P × Q pixels 31, and each pixel 31 is provided with an opening. The planar shape of the opening is a rectangle. When the planar shape of the opening is rectangular, Fraunhofer diffraction occurs, and M × N sets of diffracted light are generated. That is, such an aperture forms an amplitude grating that periodically modulates the amplitude (intensity) of the incident light wave and obtains a light amount distribution that matches the light transmittance distribution of the grating.

  Similar to the first embodiment, one pixel 31 is an overlapping region of the transparent first electrode and the transparent second electrode and includes a region including a liquid crystal cell. Then, by operating the liquid crystal cell as a kind of light shutter (light valve), that is, by controlling the light transmittance of each pixel 31, the light transmittance of the illumination light emitted from the light source 10E is controlled. As a whole, a two-dimensional image can be obtained. In the overlapping region of the transparent first electrode and the transparent second electrode, a rectangular opening is provided, and when the illumination light emitted from the light source 10E passes through the opening, Fraunhofer diffraction occurs. M × N diffracted light is generated. In other words, since the number of pixels 31 is P × Q, it can be considered that a total of (P × Q × M × N) diffracted lights are generated. In the two-dimensional image forming apparatus 30, the spatial frequency in the two-dimensional image is emitted from the two-dimensional image forming apparatus 30 along diffraction angles corresponding to a plurality of diffraction orders (total M × N) generated from each pixel 31. . The diffraction angle varies depending on the spatial frequency in the two-dimensional image.

In the three-dimensional image display device 1E of Example 10, the Fourier transform image forming means 40 is composed of a lens (first lens L _1), the front focal plane of the lens (first lens L ₁₎ (light source The light modulation means 30 is disposed on the side focal plane.

In the three-dimensional image display device 1E according to the tenth embodiment, a Fourier transform image selection unit 50 that selects a Fourier transform image corresponding to a desired diffraction order among the Fourier transform images generated by a number corresponding to a plurality of diffraction orders. Is provided. Here, the Fourier transform image selection means 50 is arranged at a position where an Fourier transform image is formed (an XY plane or an image plane on which a Fourier transform image is formed by the Fourier transform image forming means 40). Specifically, the Fourier transform image selection means 50 is disposed on the rear focal plane (observer focal plane) of the lens (first lens L ₁ ) constituting the Fourier transform image formation means 40. Alternatively, 495. In other words, the three-dimensional image display device 1E of Example 10, has a number of closing controllable opening 51 corresponding to the number of light emitting positions of the light source 10E, the first lens L ₁ A spatial filter SF located on the rear focal plane is provided. That is, the Fourier transform image selection means 50 (the spatial filter SF), the number of light emitting positions discretely arranged light source _{10E (U 0 × V 0 =} LEP Total) number corresponding to the (U ₀ × V ₀ = LEP _Total ) opening 51.

Here, more specifically, the Fourier transform image selection means 50 (or the spatial filter SF) is, for example, a transmissive liquid crystal display device using a ferroelectric liquid crystal having U ₀ × V ₀ pixels or a reflection. Type liquid crystal display device or a two-dimensional type MEMS including a device in which movable mirrors are arranged in a two-dimensional matrix. Here, for example, the opening / closing control of the opening 51 can be performed by operating the liquid crystal cell as a kind of optical shutter (light valve), and the opening / closing control of the opening 51 can be performed by moving / non-moving the movable mirror. It can be carried out. In the Fourier transform image selection means 50 (spatial filter SF), a desired opening 51 (specifically, for passing the 0th-order diffracted light in synchronization with the generation timing of the two-dimensional image by the light modulation means 30). By opening the opening 51), a Fourier transform image corresponding to a desired diffraction order (0th order) can be selected.

Further, the three-dimensional image display device 1E forms a real image RI of the two-dimensional image generated by the light modulation unit 30 by performing inverse Fourier transform on the Fourier transform image formed by the Fourier transform image forming unit 40. Inverse Fourier transform means (specifically, a second lens L ₂ described later) is further provided.

In the tenth embodiment, the first lens L ₁ , the second lens L ₂ , and the third lens L ₃ are specifically composed of convex lenses.

As described above, the two-dimensional image forming apparatus 30 is disposed on the front focal plane (focal plane on the light source side) of the first lens L ₁ having the focal length f _1, and the rear side of the _first lens L ₁ . A spatial filter SF capable of temporal opening / closing control for spatially and temporally filtering the Fourier transform image is disposed on the focal plane (observer-side focal plane). Then, the number of Fourier transform images corresponding to a plurality of diffraction orders is generated by the first lens L ₁ , and these Fourier transform images are formed on the spatial filter SF.

FIG. 33 shows a schematic front view of a light source 10E composed of a plurality of light emitting elements arranged in a two-dimensional matrix, and FIG. 34 shows a schematic front view of a spatial filter SF made up of a liquid crystal display device. In FIGS. 33 and 34, numerals (u, v) indicate the position numbers of the light-emitting elements constituting the light source 10E or the openings 51 constituting the spatial filter SF. That is, for example, in the (3, 2) th opening 51, a desired Fourier transform image (for example, Fourier corresponding to 0th-order diffraction) of a two-dimensional image by the (3, 2) th light emitting element is provided. Only the (converted image) enters and passes through the (3, 2) -th opening 51. A Fourier transform image other than the desired Fourier transform image of the two-dimensional image by the (3, 2) th light emitting element is blocked by the spatial filter SF. A spatial filter SF is disposed on the front focal plane of the second lens L ₂ having the focal length f ₂ . Furthermore, the back focal plane of the second lens L _2, such that the third front focal plane of the lens L ₃ with a focal length f ₃ matches, the second lens L ₂ and third lens L ₃ is arranged. The planar shape of the opening 51 in the spatial filter SF may be the same as that in the first embodiment.

As described above, specifically, the conjugate image forming unit 60 includes the second lens L ₂ and the third lens L ₃ . The second lens L ₂ having the focal length f ₂ performs the inverse Fourier transform on the Fourier transform image filtered by the spatial filter SF, thereby realizing the real image RI of the two-dimensional image formed by the two-dimensional image forming apparatus 30. Form. That is, the second lens L ₂ is disposed so that a real image RI of the two-dimensional image formed by the two-dimensional image forming apparatus 30 is formed on the rear focal plane of the second lens L ₂ . The magnification of the real image RI obtained here with respect to the two-dimensional image forming apparatus 30 can be changed by arbitrarily selecting the focal length f ₂ of the second lens L ₂ . The third lens L ₃ having a focal length f ₃ forms a conjugate image CI of the Fourier transform image filtered by the spatial filter SF.

Here, since the rear focal plane of the third lens L ₃ is a conjugate plane of the spatial filter SF, it is generated by the two-dimensional image forming apparatus 30 from a portion corresponding to one opening 51 on the spatial filter SF. This is equivalent to the output of the two-dimensional image. The amount of light finally generated and output is the number of pixels (P × Q), and is the light that has passed through the spatial filter SF. That is, the amount of light passing through the spatial filter SF is not substantially reduced by passing and reflecting the subsequent components of the three-dimensional image display device. Further, a conjugate image CI of the Fourier transform image is formed on the rear focal plane of the third lens L ₃ , but the directional component of the conjugate image of the two-dimensional image is emitted from the light source 10E, and the two-dimensional image forming apparatus 30. Therefore, it can be considered that the light beam group is two-dimensionally arranged in the rear focal plane of the third lens L ₃ . That is, as a whole, a plurality of projector units 301 shown in FIG. 52 (specifically U ₀ ××) are provided on the rear focal plane of the third lens L ₃ (the surface on which the conjugate image CI is formed). V ₀ ), which is equivalent to the arranged state.

As schematically shown in FIGS. 32A and 32B, one pixel 31 in the two-dimensional image forming apparatus 30 causes a total of M × N sets of diffracted light along the X and Y directions. Generated. In FIGS. 32A and 32B, zero-order light (n ₀ = 0), ± first-order light (n ₀ = ± 1), and ± second-order light (n ₀ = ± 2) are shown. Although only the diffracted light is shown as a representative, actually, higher-order (for example, ± 5th order) diffracted light is generated, and a part of these diffracted light (specifically, for example, 0 Based on the next light, a stereoscopic image is finally formed. Incidentally, (A) in FIG. 32, the diffracted light formed by a light ray emitted from the light emitting element 11 _B schematically show, in FIG. 32 (B) is formed by light rays emitted from the light emitting element 11 _A The diffracted light made is schematically shown. Here, all image information (information of all pixels) of the two-dimensional image formed by the two-dimensional image forming apparatus 30 is collected in the diffracted light (light beam) of each diffraction order. A plurality of light ray groups generated by diffraction from the same pixel on the two-dimensional image forming apparatus 30 all have the same image information at the same time. In other words, in the two-dimensional image forming apparatus 30 including a transmissive liquid crystal display device having P × Q pixels 31, the illumination light from the light source 10E is modulated by each pixel 31 to generate a two-dimensional image. The spatial frequency in the generated two-dimensional image is emitted along diffraction angles corresponding to a plurality of diffraction orders (total M × N) generated from each pixel 31. That is, M × N types of copies of the two-dimensional image are emitted from the two-dimensional image forming apparatus 30 along diffraction angles corresponding to a plurality of diffraction orders (total M × N).

Then, the spatial frequency in the two-dimensional image in which all the image information of the two-dimensional image generated by the two-dimensional image forming apparatus 30 is aggregated is Fourier transformed by the first lens L ₁ , and a plurality of diffractions generated from each pixel 31 A number of Fourier transform images corresponding to the order are generated. Then, among these Fourier transform images, only a predetermined Fourier transform image (for example, a Fourier transform image corresponding to the 0th-order diffraction) is passed through the spatial filter SF. Inverse Fourier transform is performed by the _second lens L ₂ , and a conjugate image of the two-dimensional image generated by the two-dimensional image forming apparatus 30 is formed. The conjugate image of the two-dimensional image is incident on the _third lens L ₃ , A conjugate image CI is formed by the third lens L ₃ . Note that the spatial frequency in the two-dimensional image corresponds to image information in which the spatial frequency of the pixel structure is a carrier frequency, but only in a region of image information having a 0th-order plane wave as a carrier wave (that is, the maximum spatial frequency of the pixel structure). In other words, it is obtained as first-order diffraction using the 0th-order diffraction of the plane wave component as the carrier frequency, and the spatial frequency of the pixel structure (aperture structure) of the light modulation means Less than half of the spatial frequencies pass through the spatial filter SF. Thus, in the conjugate image of the two-dimensional image formed by the third lens L ₃ , the pixel structure of the two-dimensional image forming apparatus 30 is not included, while the 2 generated by the two-dimensional image forming apparatus 30. All of the spatial frequencies in the dimensional image are included. Since the third lens L ₃ generates a Fourier transform image having a spatial frequency in the conjugate image of the two-dimensional image, a Fourier transform image can be obtained with a spatially high density.

As described above, according to the three-dimensional image display device 1E of the tenth embodiment, the predetermined light emitting element 11 emits light, while the desired opening 51 in the Fourier transform image selection means 50 (spatial filter SF) is opened. To do. Therefore, the spatial frequency in the two-dimensional image generated by the light modulation means (two-dimensional image forming apparatus) 30 is emitted along diffraction angles corresponding to a plurality of diffraction orders, and the Fourier transform image forming means 40 (first The Fourier transform image obtained by Fourier transform by the lens L ₁ ) is spatially and temporally filtered by the Fourier transform image selection means 50 (spatial filter SF), and the filtered Fourier transform image. Since the conjugate image CI is formed, the light beam group is generated and scattered in a spatially high density and distributed in a plurality of directions without increasing the size of the entire three-dimensional image display device. can do. In addition, each light beam that is a constituent element of the light beam group can be independently controlled temporally and spatially. As a result, it is possible to obtain a three-dimensional image using light rays that are close to the same quality as real-world objects.

Further, according to the three-dimensional image display device 1E of the tenth embodiment, since the light beam reproduction method is used, it is possible to provide a stereoscopic image that satisfies visual functions such as focus adjustment, convergence, and motion parallax. . Furthermore, according to the three-dimensional image display device 1E of the tenth embodiment, illumination light having different incident directions to the two-dimensional image forming device 30 depending on a plurality of discretely arranged light emission positions can be efficiently used. Therefore, as compared with the conventional image output method, the number of light beams that can be controlled by one image output device (two-dimensional image forming apparatus 30) is the same as the number of discrete light output positions (that is, , U ₀ × V ₀ ). In addition, according to the three-dimensional image display device 1E of the tenth embodiment, spatial and temporal filtering is performed, so that the temporal characteristics of the three-dimensional image display device are changed to the spatial characteristics of the three-dimensional image display device. Can be converted. In addition, a stereoscopic image can be obtained without using a diffusion screen or the like. Furthermore, it is possible to provide an appropriate stereoscopic image for observation from any direction. In addition, since a group of light beams can be generated and scattered at a high spatial density, a fine spatial image close to the visual recognition limit can be provided.

The eleventh embodiment is a modification of the tenth embodiment. In Example 11, the light source 10E includes a plurality of light emitting elements 11 arranged in a two-dimensional matrix, and the light emitting elements 11 are arranged so that the emission directions of the light emitted from the light emitting elements 11 are different. is doing. As a result, the light modulator or the two-dimensional image forming apparatus can be illuminated with illumination light sequentially emitted from different light emission positions of the light source and having different incident directions. FIG. 35 shows a conceptual diagram of the three-dimensional image display device when the light source having such a configuration is adopted in the three-dimensional image display device of Example 11. Note that in FIG. 35 shows the one light flux emitted from the light emitting element 11 _A constituting the light source 10E by a solid line, shows a single light flux emitted from the light emitting element 11 _B by a one-dot chain line, the light emitting element 11 One of the light beams emitted from _C is indicated by a dotted line. In addition, the positions of the images in the spatial filter SF formed by the illumination light emitted from the light emitting elements 11 _A , 11 _B , and 11 _C are denoted by reference numerals (11 _A ), (11 _B ), and (11 _C ), respectively. , The positions of the images on the rear focal plane of the third lens L ₃ formed by the illumination light emitted from the light emitting elements 11 _A , 11 _B , and 11 _{C are} denoted by reference numerals (11 _a ) and (11 _b ), respectively. , (11 _c ). Further, it is a conceptual diagram in which the vicinity of the light modulation means (two-dimensional image forming apparatus) 30, the Fourier transform image formation means 40 (first lens L ₁ ), and the Fourier transform image selection means 50 (spatial filter SF) are enlarged. , Schematically shows a state in which the light beams emitted from the light emitting elements 11 _A , 11 _B , and 11 _C constituting the light source 10E pass through the two-dimensional image forming apparatus 30, the first lens L ₁ , and the spatial filter SF. FIG. 36, FIG. 37, and FIG. The position numbers of the light emitting elements 11 _A , 11 _B , 11 _C constituting the light source 10E are, for example, the (5,0) th, (0,0) th, and (−5,0). ) Th. Here, when a certain light emitting element is in a light emitting state, all other light emitting elements are turned off. In FIG. 35, reference numeral 20 denotes an illumination optical system composed of a lens for shaping illumination light.

  In Example 10 or Example 11, the light source may include a light emitting element and a light beam traveling direction changing unit for changing the traveling direction of light emitted from the light emitting element. it can. Specifically, for example, the inclination angle of the rotation axis may be controlled while rotating the polygon mirror around the rotation axis. Alternatively, the light traveling direction changing means is composed of a convex mirror composed of a curved surface, a concave mirror composed of a curved surface, a convex mirror composed of a polyhedron, and a concave mirror composed of a polyhedron, and the illumination light emitted from the mirror The light emission position of the light beam may be changed (changed) by controlling the mirror position and the like.

In the tenth or eleventh embodiment, instead of the spatial filter SF (Fourier transform image selection means 50), the first lens L has a number of openings corresponding to the number of light emission positions. It can also be set as the structure provided with the scattering diffraction limiting member located in ₁ back focal planes. This scattering diffraction limiting member can be produced, for example, by providing an opening (for example, a pinhole) in a plate-like member that does not transmit light. Here, the position of the opening is a desired Fourier transform image (for example, having a 0th diffraction order) in a Fourier transform image (or diffracted light) obtained by the Fourier transform image selection means or the first lens. Alternatively, the position of the diffracted light) may be set as a position where the image is formed, and the position of the opening may correspond to the light emission positions arranged discretely.

  The twelfth embodiment is a modification of the various embodiments described above. A conceptual diagram of the three-dimensional image display device of Example 12 is shown in FIG. In the three-dimensional image display devices of Examples 1 to 11, the light transmission type two-dimensional image forming device 30 was used. On the other hand, in the three-dimensional image display apparatus according to the twelfth embodiment, a reflection type light modulation means (two-dimensional image forming apparatus) 30 'is used. As the reflection type light modulation means (two-dimensional image forming apparatus) 30 ', for example, a reflection type liquid crystal display device can be cited.

  In the three-dimensional image display device according to the twelfth embodiment, a beam splitter 70 is provided on the z-axis (optical axis). The beam splitter 70 has a function of transmitting or reflecting light depending on the difference in polarization components. The beam splitter 70 reflects light (illumination light) emitted from the light sources 10 and 10E toward the reflective light modulation means (two-dimensional image forming apparatus) 30 '. Further, the reflected light from the light modulation means (two-dimensional image forming apparatus) 30 'is transmitted. Except for this point, the configuration and structure of the three-dimensional image display device according to the twelfth embodiment can be the same as the configuration and structure of the three-dimensional image display device according to the first to eleventh embodiments. Omitted.

  In addition, as a reflection-type light modulation means (two-dimensional image forming apparatus), depending on the form of the embodiment, a configuration in which movable mirrors are provided in the openings instead (movable mirrors are in a two-dimensional matrix shape). In this case, a two-dimensional image is generated by moving / non-moving the movable mirror, and Fraunhofer diffraction is generated by the aperture. . Note that when a two-dimensional MEMS is employed, a beam splitter is not necessary, and illumination light may be incident on the two-dimensional MEMS from an oblique direction.

  Hereinafter, the timing of opening / closing control of the opening 51 in the spatial filter SF in Examples 1 to 7 and Examples 10 to 11 will be described.

  In the spatial filter SF, in order to select a Fourier transform image corresponding to a desired diffraction order, the opening / closing control of the opening 51 is performed in synchronization with the image output of the two-dimensional image forming apparatus 30. This operation will be described with reference to FIG. 40, FIG. 41, and FIG. 40 shows the image output timing in the two-dimensional image forming apparatus 30, and the middle stage in FIG. 40 shows the opening / closing timing of the (3, 2) -th opening 51 in the spatial filter SF. The lower part of FIG. 40 shows the opening / closing timing of the (3, 3) th opening 51.

As shown in FIG. 40, in the two-dimensional image forming apparatus 30, for example, the image “A” is displayed during the time t _{1S to} t _1E (period TM ₁ ), and during the time t _{2S to} t _2E (period TM _2). ) Is displayed as an image “B”. At this time, in Examples 1 to 7, in the spatial filter SF, as shown in FIG. 40, the the period TM ₁ the (3, 2) th aperture 51, the period TM ₂ second ( The third and third openings 51 are set in the open state. In this way, different diffraction orders are generated in the same pixel 31 in the two-dimensional image forming apparatus 30 (or the same aperture region 34 in the oversampling filter OSF or the same optical element 36 constituting the optical device 35). Different image information can be added to the Fourier transform image generated by the lens L ₁ or the third lens L ₃ . In other words, in the period TM ₁ , a certain pixel 31 in the two-dimensional image forming apparatus 30 (or an opening region 34 in the oversampling filter OSF or an optical element 36 constituting the optical device 35). The Fourier transform image having the diffraction order of m ₀ = 3 and n ₀ = 2 obtained in FIG. 4 includes image information related to the image “A”. On the other hand, in the period TM _2, the same one pixel in the two-dimensional image forming apparatus 30 31 (alternatively, the same one opening region 34 in the oversampling filter OSF Alternatively, the same one optical element constituting the optical device 35 36 The Fourier transform image having the diffraction orders of m ₀ = 3 and n ₀ = 3 obtained in () includes image information related to the image “B”.

Also in the tenth embodiment, as shown in FIG. 40, in the two-dimensional image forming apparatus 30, for example, the image “A” is displayed during the time t _{1S to} t _1E (period TM ₁ ), and the time t It is assumed that the image “B” is displayed between _{2S and} t _2E (period TM ₂ ). At this time, in the light source 10E is only the period TM ₁ the (3, 2) -th light emitting element is a light emitting state, the period TM ₂ the (3,3) th and only a light emitting state light-emitting element. In this way, illumination light that is sequentially emitted from a plurality of light emission positions arranged in a discrete manner and has different incident directions to the two-dimensional image forming apparatus 30 is used, and the illumination light is modulated by each pixel 31. . On the other hand, in the spatial filter SF, as shown in FIG. 40, the the period TM ₁ the (3, 2) th aperture 51, the the period TM ₂ the (3,3) th aperture 51 opened And In this way, different image information can be added to the Fourier transform image generated as different diffraction orders in the same pixel 31 in the two-dimensional image forming apparatus 30 and generated by the first lens L ₁ . In other words, in the period TM ₁ , the (3, 2) -th light emitting element is brought into a light emitting state, whereby a Fourier transform having a zero-order diffraction order obtained in a certain pixel 31 in the two-dimensional image forming apparatus 30. The image includes image information related to the image “A” and incident direction information of the illumination light to the two-dimensional image forming apparatus 30. On the other hand, in the period TM ₂ , the (3, 3) -th light emitting element is brought into the light emitting state, thereby obtaining a Fourier transform image having the 0th-order diffraction order obtained in the same certain pixel in the two-dimensional image forming apparatus 30. Includes image information related to the image “B” and incident direction information of the illumination light to the two-dimensional image forming apparatus 30.

FIG. 41 schematically shows the timing of image formation and the timing of controlling the opening 51 in the two-dimensional image forming apparatus 30. In the period TM ₁ , the image “A” is displayed in the two-dimensional image forming apparatus 30, and M × N Fourier transform images are Fourier transformed images in the corresponding (3, 2) th opening 51 of the spatial filter SF. Focused as “α”. In the period TM ₁ , since only the (3, 2) -th opening 51 is opened, only the Fourier transform image “α” having diffraction orders of m ₀ = 3 and n ₀ = 2 (in the tenth embodiment, , Only the Fourier transform image “α” having the 0th-order diffraction order) passes through the spatial filter SF. In the next period TM ₂ , the image “B” is displayed in the two-dimensional image forming apparatus 30, and similarly, the M × N Fourier transform images correspond to the (3, 3) th corresponding to the spatial filter SF. The aperture 51 is condensed as a Fourier transform image “β”. In the period TM ₂ , since only the (3, 3) th opening 51 is opened, only the Fourier transform image “β” having a diffraction order of m ₀ = 3, n ₀ = 3 (in the tenth embodiment, , Only the Fourier transform image “β” having the 0th-order diffraction order) passes through the spatial filter SF. Thereafter, the opening / closing control of the opening 51 in the spatial filter SF is sequentially performed in synchronization with the image forming timing of the two-dimensional image forming apparatus 30. In FIG. 41, the opening 51 in the open state is surrounded by a solid line, and the opening 51 in the closed state is surrounded by a dotted line. Here, in Example 10, when the space occupied by the spatial filter SF is viewed for a certain length of time, U ₀ × V ₀ bright spots (Fourier transform images) are arranged in a two-dimensional matrix. A state (a state similar to the state shown in FIG. 4) will be seen.

FIG. 42 schematically shows an image obtained as the final output of the three-dimensional image display device when image formation in the two-dimensional image forming device 30 and opening / closing control of the opening 51 are performed at such timing. . In FIG. 42, since the image “A ′” opens only the (3, 2) -th opening 51, only the Fourier transform image “α” having diffraction orders of m ₀ = 3 and n ₀ = 2 (implementation). In Example 10, an image obtained as a result of the Fourier transform image “α” having the 0th-order diffraction order when the (3, 2) -th light-emitting element is in the light-emitting state passes through the spatial filter SF. It is. In addition, since the image “B ′” opens only the (3, 3) -th opening 51, only the Fourier transform image “β” having diffraction orders of m ₀ = 3 and n ₀ = 3 (Example 10). In this case, only the Fourier transform image “β” having the zeroth diffraction order when the (3, 3) th light emitting element is in the light emitting state is an image obtained as a result of passing through the spatial filter SF. . Further, since the image “C ′” opens only the (4, 2) th opening 51, only the Fourier transform image “γ” having diffraction orders of m ₀ = 4 and n ₀ = 2 (Example) 10 is an image obtained as a result of passing a Fourier transform image “γ” having a 0th-order diffraction order when the (4,2) light-emitting element is in a light-emitting state through the spatial filter SF. is there. Note that the image shown in FIG. 42 is an image viewed by an observer. In FIG. 42, for convenience, the image and the image are separated by a solid line, but the solid line is a virtual solid line. In addition, to be exact, the image shown in FIG. 42 is not obtained at the same time, but since the image switching period is very short, it is observed as if it is simultaneously displayed to the eyes of the observer. The For example, image formation for all orders (M × N) in the two-dimensional image forming apparatus 30 (or oversampling filter OSF) and selection of one image in the spatial filter SF are performed within a display period of one frame. In the tenth embodiment, however, (U ₀ × V ₀ ) images are selected based on all the discretely arranged light emission positions within one frame display period. Further, although it is illustrated in a plan view in FIG. 42, what is actually observed by the observer is a stereoscopic image.

That is, in Examples 1 to 7 and Examples 10 to 11, as described above, two-dimensional image formation is performed from the rear focal plane of the third lens L ₃ or the fifth lens L _5. 2-dimensional image produced by the apparatus 30, or alternatively, the conjugate image of the two-dimensional image generated by the second lens L ₂ (for example, in time series, the image "a '", the image "B'" ... -Image "C '") is output. That is, as a whole, the projector unit 301 shown in FIG. 52 has a plurality of diffraction orders (specifically M × N) on the rear focal plane of the third lens L ₃ or the fifth lens L ₅ . ) Or a plurality of discretely arranged light emission positions (specifically, U ₀ × V ₀ ), which are arranged in time series from a certain projector unit 301. A ′ ”is output, an image“ B ′ ”is output from another projector unit 301, and an image“ C ′ ”is output from another projector unit 301. For example, if the image is reproduced in time series in the two-dimensional image forming apparatus 30 based on data of a large number of images (or images created by a computer) obtained by photographing a certain object from various positions (angles). A stereoscopic image can be obtained based on these images.

  Next, the timing of the position control of the light beam traveling direction changing means 80 in the eighth or ninth embodiment will be described.

To image an image having a direction component by the third lens L _3, in synchronization with the image output of the two-dimensional image forming apparatus 30 performs position control of the light ray traveling direction change means 80. This operation will be described with reference to FIGS. 40, 41, 42, and 43. FIG. 40 shows the image output timing in the two-dimensional image forming apparatus 30, and the middle stage in FIG. 40 shows the position of the (3, 2) -th image formation in the light beam traveling direction changing means 80. The timing of control is shown, and the lower part of FIG. 40 shows the timing of position control of the (3, 3) -th image formation.

As shown in FIG. 40, in the two-dimensional image forming apparatus 30, for example, the image “A” is displayed during the time t _{1S to} t _1E (period TM ₁ ), and during the time t _{2S to} t _2E (period TM _2). ) Is displayed as an image “B”. At this time, in the light traveling direction changing means 80, as shown in FIG. 40, the period TM _1, the (3, 2) th position control, such as imaging is obtained is made, the period TM _2, the Position control is performed so that the (3, 3) -th image is obtained. In FIG. 43, the light beam traveling direction changing means 80 that is in the position control state so as to obtain the (3, 2) -th image formation is indicated by a dotted line, and the image obtained on the image plane IS. Is conceptually indicated by “A”, and the light ray traveling direction changing means 80 in the position control state capable of obtaining the (3, 3) -th image formation is indicated by a solid line and obtained on the image plane IS. The image is conceptually indicated by “B”. In this way, different image information (direction component) can be added to the Fourier transform image generated by the first lens L ₁ . Stated words, the period TM _1, the Fourier transform image, the image information is included relating to the image "A". On the other hand, in the period TM _2, the Fourier transform image, the image information is included relating to the image "B".

FIG. 41 schematically shows the timing of image formation in the two-dimensional image forming apparatus 30 and the timing of position control of the light beam traveling direction changing means 80. In the period TM ₁ , the image “A” is displayed in the two-dimensional image forming apparatus 30 and is condensed as a Fourier transform image “α” on the light beam traveling direction changing unit 80. In the period TM ₁ , the (3, 2) -th image is obtained. In the next period TM ₂ , the image “B” is displayed in the two-dimensional image forming apparatus 30, and is similarly condensed as a Fourier transform image “β” on the light beam traveling direction changing means 80. In the period TM ₂ , the (3, 3) -th image is obtained. Thereafter, the position control of the light beam traveling direction changing unit 80 is sequentially performed in synchronization with the image forming timing of the two-dimensional image forming apparatus 30. In FIG. 41, the image forming position on the image forming plane IS is surrounded by a solid line, and the image forming position at another timing of the position control of the light beam traveling direction changing means 80 is surrounded by a dotted line.

  It is necessary to synchronize the change in the traveling direction of the light beam by the light traveling direction changing unit 80 with the generation of the two-dimensional image based on the two-dimensional image forming apparatus 30. After forming an image (for example, “α”), the position of the light beam traveling direction changing unit 80 is changed (changed), and the light beam traveling direction changing unit 80 changes the position of the next image (for example, “β”). Until the image is formed, the operation of the light source 10 is interrupted, and the two-dimensional image forming apparatus 30 does not generate a two-dimensional image.

When the image formation in the two-dimensional image forming apparatus 30 and the position control of the light beam traveling direction changing unit 80 are performed at such timing, an image obtained as the final output of the three-dimensional image display apparatus is schematically shown in FIG. Indicate. In FIG. 42, an image “A ′” is an image obtained as a result of the (3, 2) -th image formation, and an image “B ′” is obtained as a result of the (3, 3) -th image formation. The image “C ′” is an image obtained as a result of the (4, 2) -th image formation. For example, within a display period of one frame, generation of a two-dimensional image of the number of times (S ₀ × T ₀ ) and position control of the light beam traveling direction changing unit 80 are performed.

That is, in Example 8 or Example 9, as described above, the two-dimensional image generated by the second lens L ₂ from the rear focal plane (imaging plane IS) of the third lens L _3. Are output (for example, image “A ′”, image “B ′”... Image “C ′” in time series). That is, as a whole, a plurality (specifically, S ₀ × T ₀ ) of projector units 301 shown in FIG. 52 are arranged on the rear focal plane of the third lens L ₃ . In series, an image “A ′” is output from one projector unit 301, an image “B ′” is output from another projector unit 301, and an image “C ′” is output from another projector unit 301. When output, it is equivalent. For example, if the image is reproduced in time series in the two-dimensional image forming apparatus 30 based on data of a large number of images (or images created by a computer) obtained by photographing a certain object from various positions (angles). A stereoscopic image can be obtained based on these images.

  Next, the configuration and structure of the diffraction grating-light modulation element 210 will be described.

  The arrangement of the lower electrode 212, the fixed electrode 221, the movable electrode 222, and the like constituting the diffraction grating-light modulation element 210 is schematically shown in FIG. In FIG. 44, the lower electrode 212, the fixed electrode 221, the movable electrode 222, and the support portions 214, 215, 217, and 218 are hatched for clarity.

  The diffraction grating-light modulation element 210 includes a lower electrode 212, a band-shaped (ribbon-shaped) fixed electrode 221, and a band-shaped (ribbon-shaped) movable electrode 222. The lower electrode 212 is formed on the support 211. The fixed electrode 221 is supported by the support portions 214 and 215 and supported and stretched above the lower electrode 212. Further, the movable electrode 222 is supported by support portions 217 and 218, supported and stretched above the lower electrode 212, and juxtaposed with the fixed electrode 221. In the illustrated example, one diffraction grating-light modulation element 210 is composed of three fixed electrodes 221 and three movable electrodes 222. The three movable electrodes 222 are collectively connected to the control electrode, and the control electrode is connected to a connection terminal portion (not shown). On the other hand, the three fixed electrodes 221 are collectively connected to the bias electrode. The bias electrode is common to the plurality of diffraction grating-light modulation elements 210 and is grounded via a bias electrode terminal portion (not shown). The lower electrode 212 is also common to the plurality of diffraction grating-light modulation elements 210, and is grounded via a lower electrode terminal portion (not shown).

  When a voltage is applied to the movable electrode 222 via the connection terminal portion and the control electrode and a voltage is applied to the lower electrode 212 (actually, the lower electrode 212 is in a ground state), the movable electrode 222 and the lower electrode 212 are applied. Electrostatic force (Coulomb force) is generated between The movable electrode 222 is displaced downward toward the lower electrode 212 by the electrostatic force. The state before displacement of the movable electrode 222 is shown on the left side of FIGS. 45A and 45C, and the state after displacement is shown on the right side of FIGS. 45B and 45C. Show. Based on such displacement of the movable electrode 222, a reflective diffraction grating is formed by the movable electrode 222 and the fixed electrode 221. Here, FIG. 45A is a schematic cross-sectional view of a fixed electrode and the like along arrow BB in FIG. 44, and a schematic view of a movable electrode and the like along arrow AA in FIG. FIG. 45 is a cross-sectional view (provided that the diffraction grating-light modulation element is not in operation), and FIG. 45B is a schematic cross-sectional view of movable electrodes and the like along arrow AA in FIG. (However, the diffraction grating-light modulation element is in operation). FIG. 45C is a schematic cross section of the fixed electrode, the movable electrode, etc. along the arrow CC in FIG. FIG.

The distance between adjacent fixed electrodes 221 is d (see FIG. 45C), the wavelength of light (incident angle: θ _i ) incident on the movable electrode 222 and the fixed electrode 221 is λ, and the diffraction angle is θ _m . Then
d [sin (θ _i ) −sin (θ _m )] = m _Dif · λ
Can be expressed as Here, m _Dif is an order and takes values of 0, ± 1, ± 2 _,.

When the difference Δh _{1 in} height between the top surface of the movable electrode 222 and the top surface of the fixed electrode 221 (see FIG. 45C) is (λ / 4), the light intensity of the diffracted light is the maximum value. Become.

In the light modulation means, the movable electrode 222 and the stationary electrode 222 are fixed when the diffraction grating-light modulation element 210 in the state shown in the left side of FIGS. 45 (A) and 45 (C) is inoperative. Light reflected from the top surface of the electrode 221 is blocked by the spatial filter 204. On the other hand, the movable electrode 222 is diffracted by the movable electrode 222 and the fixed electrode 221 when the diffraction grating-light modulation element 210 is in the state shown on the right side of FIGS. 45B and 45C. First-order (m _Dif = ± 1) diffracted light passes through the spatial filter 204. With such a configuration, light on / off control can be controlled. Further, by changing the voltage applied to the movable electrode 222, the height difference Δh ₁ between the top surface of the movable electrode 222 and the top surface of the fixed electrode 221 can be changed. As a result, the intensity of the diffracted light can be increased. The gradation control can be performed by changing.

  Next, structural examples of the light source and the illumination optical system in Examples 1 to 9 are shown in FIGS. 46 (A) to 46 (C) and FIGS. 47 (A) to 47 (B). Here, the characteristics of light (illumination light) emitted from the light source, shaped by the illumination optical system, and illuminating the two-dimensional image forming apparatus 30 will be described below using spatial coherence.

  Spatial coherence indicates the coherence of light that occurs in a cross section in an arbitrary space, and the degree thereof can be indicated by the contrast of the generated interference fringes. In the process of generating interference fringes, the interference fringes with the highest contrast are generated by interference of plane waves or spherical waves that can be optically exchanged with plane waves. This shows that the light with the highest spatial coherence is a plane wave (or spherical wave). For example, a plane wave having only one traveling direction component has the highest spatial coherence, and as the degree of spatial coherence decreases, a plurality of traveling direction components exist. Further, the distribution of the light traveling direction component is equivalent to discussing the spatial size of the light emission origin or the secondary light emission point. From the above, the spatial coherence can be discussed based on the spatial size of the light emission origin or the secondary light emission point. Spatial coherence, that is, the spatial size of the light source is a factor that determines the spatial frequency characteristics of the image in the three-dimensional image display device. When light other than light having perfect spatial coherence is used as illumination light, the contrast decreases in order from the high frequency component. Since the spatial frequency characteristics of the obtained image have different requirements depending on specific applications, various configuration methods for flexibly responding to different requirements will be described here without referring to specific numerical values.

  In the three-dimensional image display apparatuses 1A to 1D according to the first to ninth embodiments, the configuration method of the light source and the illumination optical system is different between the case where light having high spatial coherence is used as the illumination light and the case where it is not. Further, the configuration of the illumination optical system differs depending on the characteristics of the light source. Below, the combination of the structural method in a light source and an illumination optical system is demonstrated. In all cases, it is assumed that the light source is a single color or a light source close to a single color.

(A) in FIG. 46, as a first configuration example, the high light source 10 ₁ spatial coherence, shows an example in which the high illumination optical system 20 ₁ spatial coherence as a whole. Light source 10 ₁ is constituted, for example, from a laser. The illumination optical system 20 ₁ includes a lens 21 ₁ , a circular aperture plate 22 ₁ , and a lens 24 _{1 in} order from the light source side. The circular aperture plate 22 ₁ is provided with a circular aperture 23 ₁ at the center. An aperture 23 ₁ is disposed at the condensing position of the lens 24 ₁ . The lens 24 ₁ functions as a collimator lens.

FIG. 46B shows an example in which the illumination optical system 20 ₂ having a low spatial coherence as a whole is configured using a light source 10 ₂ having a high spatial coherence as a second configuration example. Light source 10 ₂ is composed, for example, from a laser. The illumination optical system 20 ₂ includes a lens 21 ₂ , a diffusion plate 22 ₂ , and a lens 24 _{2 in} order from the light source side. The diffusion plate 22 ₂ may be a movable diffusion plate.

46C and 47A show illumination optical systems having high spatial coherence as a whole, using light sources 10 ₃ and 10 ₄ having low spatial coherence as the third and fourth configuration examples. An example in which 20 ₃ and 20 ₄ are configured is shown. As the light sources 10 ₃ and 10 ₄ , for example, a light emitting diode (LED) or a white light source is used. The illumination optical system 20 _{3 in} FIG. 46C includes a lens 21 ₃ , a circular aperture plate 22 ₂ , and a lens 24 _{3 in} order from the light source side. The circular aperture plate 22 ₂ is provided with a circular aperture 23 ₃ at the center. An aperture 23 ₃ is arranged at a condensing position in the lens 24 ₃ . Lens 24 ₃ functions as a collimator lens. On the other hand, in the illumination optical system 20 ₄ of FIG. 47A, the lens 21 ₃ is omitted as compared with the illumination optical system 20 ₃ of FIG. 46C, and the circular aperture plate 22 ₄ and the aperture are sequentially arranged from the light source side. 23 ₄ and a lens 24 ₄ .

In FIG. 47 (B), as a fifth configuration example, using a light source ₁₀₅ is not high spatial coherence, shows an example in which the illumination optical system 20 ₅ not high spatial coherence as a whole. Other than the light source 10 ₅ , the lens 24 ₅ alone is used.

  In each configuration example, when an illumination optical system having a high spatial coherence as a whole is constructed, the secondary emission point is reduced without depending on the light source. Further, when constructing an illumination optical system that does not have high spatial coherence as a whole, the secondary light emission point is increased without depending on the light source.

  Although the three-dimensional image display device of the present invention has been described based on the preferred embodiments, the present invention is not limited to these embodiments.

  In the fourth and fifth embodiments, the grating filter constituting the oversampling filter is constituted by the phase grating, but may alternatively be constituted by the amplitude grating.

  In the sixth embodiment, for example, two convex lenses are arranged between the two-dimensional image forming apparatus 30 and the optical apparatus 35, and the two-dimensional image forming apparatus 30 is disposed on the front focal plane of one convex lens. The front focal point of the other convex lens is positioned at the rear focal point of one convex lens, and the optical device 35 is disposed at the rear focal plane of the other convex lens. Alternatively, the optical element 36 constituting the optical device 35 can alternatively be constituted by a concave lens. In this case, the virtual opening area 37 is located in front of the two-dimensional image forming apparatus 30 (on the light source side). Furthermore, the optical element 36 may be composed of a Fresnel lens instead of a normal lens.

  In the tenth embodiment, the collimator lens 12 is arranged between the light source 10E and the light modulation means (two-dimensional image forming apparatus) 30, but instead, a microlens array in which microlenses are arranged in a two-dimensional matrix. Can also be used.

In the first and third embodiments, the light modulating means (two-dimensional image forming apparatus) 30 and the diffracted light generating means are provided on the front focal plane of the lens (first lens L ₁ ) constituting the Fourier transform image forming means 40. The Fourier transform image selection means is arranged on the rear focal plane. However, in some cases, as a result of crosstalk occurring in the spatial frequency in the two-dimensional image, the finally obtained stereoscopic image If the deterioration occurs but the deterioration is allowed, the light modulation means (two-dimensional image forming apparatus) is positioned at a position shifted from the front focal plane of the lens (first lens L ₁ ) constituting the Fourier transform image forming means 40. ) 30 or diffracted light generating means may be arranged, or Fourier transform image selecting means may be arranged at a position shifted from the rear focal plane. The first lens L ₁ , the second lens L ₂ , and the third lens L ₃ are not limited to convex lenses, and appropriate lenses may be selected as appropriate.

Also in the fourth and fifth embodiments, the oversampling filter OSF is disposed on the front focal plane of the lens (third lens L ₃ ) constituting the Fourier transform image forming means 40, and the Fourier transform is performed on the rear focal plane. The image selecting means 50 (spatial filter SF) is arranged. However, in some cases, crosstalk occurs in the spatial frequency in the conjugate image of the two-dimensional image, resulting in degradation of the finally obtained stereoscopic image. However, if such deterioration is allowed, an oversampling filter OSF may be disposed at a position shifted from the front focal plane of the lens (third lens L ₃ ) constituting the Fourier transform image forming means 40, The Fourier transform image selection means 50 (spatial filter SF) may be arranged at a position shifted from the rear focal plane. The first lens L ₁ , the second lens L ₂ , the third lens L ₃ , the fourth lens L ₄ , and the fifth lens L ₅ are not limited to convex lenses, and appropriate lenses are appropriately selected. do it.

In Example 6 and Example 7, the focal point of the optical element 36 constituting the optical device 35 is located on the front focal plane of the lens (first lens L ₁ ) constituting the Fourier transform image forming means 40. In this case, the Fourier transform image selection means is arranged on the rear focal plane. However, in some cases, crosstalk occurs in the spatial frequency of the two-dimensional image, resulting in deterioration of the finally obtained stereoscopic image. However, if such deterioration is allowed, the focal point of the optical element 36 constituting the optical device 35 is shifted from the front focal plane of the lens (first lens L ₁ ) constituting the Fourier transform image forming means 40. The Fourier transform image selection means may be arranged at a position shifted from the rear focal plane. The first lens L ₁ , the second lens L ₂ , and the third lens L ₃ are not limited to convex lenses, and appropriate lenses may be selected as appropriate.

Furthermore, in Example 8, the light ray traveling direction changing means 80 is disposed on the rear focal plane of the second lens L ₃ and on the front focal plane of the third lens L _2. The light beam traveling direction changing means 80 may be disposed at a position shifted from these focal planes. The first lens L ₁ , the second lens L ₂ , and the third lens L ₃ are not limited to convex lenses, and appropriate lenses may be selected as appropriate.

Further, in the tenth and eleventh embodiments, the light modulating means (two-dimensional image forming apparatus) 30 and the diffracted light are arranged on the front focal plane of the lens (first lens L ₁ ) constituting the Fourier transform image forming means 40. Although the generation unit is arranged and the Fourier transform image selection unit is arranged on the rear focal plane, in some cases, the resulting stereoscopic image is deteriorated, but such deterioration is allowed. If so, the light modulating means (two-dimensional image forming apparatus) 30 and the diffracted light generating means are arranged at a position shifted from the front focal plane of the lens (first lens L ₁ ) constituting the Fourier transform image forming means 40. Alternatively, the spatial filter SF (Fourier transform image selection means 50) may be arranged at a position shifted from the rear focal plane. The first lens L ₁ , the second lens L ₂ , and the third lens L ₃ are not limited to convex lenses, and appropriate lenses may be selected as appropriate.

  In the embodiment, it is assumed that the light source is a single color or a light source close to a single color in all cases, but the light source is not limited to such a configuration. The wavelength band of the light source may extend to a plurality of bands. However, in this case, for example, the three-dimensional image display apparatus 1A in the first embodiment will be described as an example. As shown in FIG. 48A, the illumination optical system 20 and the light modulation means (two-dimensional image forming apparatus) ) 30, or alternatively, taking the 3D image display device 1 </ b> E in Example 10 as an example, wavelength selection is performed between the collimator lens 12 and the light modulation means (2D image forming device) 30. It is preferable to arrange the narrow band filter 71, whereby the wavelength band can be sorted and selected, and the monochromatic light can be extracted.

  Alternatively, the wavelength band of the light source 10 may extend over a wide band. However, in this case, as shown in FIG. 48B, between the illumination optical system 20 and the light modulation means (two-dimensional image forming apparatus) 30, or alternatively, the collimator lens 12 and the light modulation means ( It is preferable to arrange a dichroic prism 72 and a narrow band filter 71G for wavelength selection between the two-dimensional image forming apparatus) 30. Specifically, the dichroic prism 72 reflects, for example, red light and blue light in different directions and transmits light including green light. A narrow band filter 71G for separating and selecting the green light is disposed on the light emission side including the green light in the dichroic prism 72.

  As shown in FIG. 49, a narrow band filter 71G for separating and selecting green light is arranged on the emission side of the light beam including green light in the dichroic prism 72, and the red light is separated on the emission side of the light beam including red light. If the narrow band filter 71R to be selected is arranged, and the narrow band filter 71B for separating and selecting the blue light is arranged on the light emission side including the blue light, the three-dimensional image display device for displaying the three primary colors can be obtained. A light source can be configured. Three three-dimensional image display devices having such a configuration are used. Alternatively, a light source that emits red light and a three-dimensional image display device, a light source that emits green light, a three-dimensional image display device, and blue light are emitted. By using a combination of a light source and a three-dimensional image display device and synthesizing images from the respective three-dimensional image display devices using, for example, a light combining prism, color display can be performed. A dichroic mirror can be used instead of the dichroic prism. Alternatively, the light source is composed of a red light emitting element, a green light emitting element, and a blue light emitting element, and the red light emitting element, the green light emitting element, and the blue light emitting element are sequentially brought into a light emitting state, thereby producing a color. Display can also be performed. Needless to say, the above-described modifications of the three-dimensional image display device can be applied to other embodiments.

1A, 1B, 1C, 1D, 1E... 3D image display device, 10, 10 ₁ , 10 ₂ , 10 ₃ , 10 ₄ , 10 ₅ ... Light source, 11 _A , 11 _B , 11 _C. -Light emitting element, 12 ... collimator lens, 20, 20 ₁ , 20 ₂ , 20 ₃ , 20 ₄ , 20 ₅ ... illumination optical system, 21 ₁ , 21 ₂ , 21 ₃ , 24 ₁ , 24 ₂ , 24 ₃ , 24 ₄ , 24 ₅ ... Lens, 22 ₁ , 22 ₂ , 22 ₄ ... Circular aperture plate, 22 ₂ ... Diffuser plate, 23 ₁ , 23 ₃ , 23 ₄ . 130: Light modulation means (two-dimensional image forming apparatus), 31 ... Pixel, 32 ... Image limiting / generating means, 33 ... Scattering diffraction limiting aperture, 34 ... Opening area, 35 ..Optical device 36... Optical element 37... Virtual aperture region 40 .Fourier transform image forming means 50. Fourier transform image selection means, 51... Opening, 52... Center position of opening, 60... Conjugate image forming means, 70 ... beam splitter, 71, 71R, 71G, 71B. Filter, 72 ... Dichroic prism, 80 ... Ray traveling direction changing means, 81 ... Beam splitter, 82 ... Imaging means, 90, 92 ... Semi-transmissive mirror, 91 ... Shielding Member 93... Lens 94 94 mirror 95 detecting means 131 scanning lens system 132 lattice filter 133 anisotropic diffusion filter 201. Diffraction grating-light modulation device, 203 ... lens, 204 ... spatial filter, 205 ... scan mirror, 210 ... diffraction grating-light modulation element, 211 ... support, 212 ... Lower electrode, 214, 2 15,217,218 ... support portion, 221 ... fixed electrode, 222 ... movable electrode, L ₁ ... the first lens, L ₂ ... second lens, L ₃ ... the third lens, L ₄ · · · fourth lens, L ₅ · · · fifth lens, SF · · · spatial filter, OSF · · · oversampling filter, RI · · · real image (inverse Fourier transform image ), CI: conjugate image of Fourier transform image

Claims (16)

A light source and an optical system,
The optical system is
(A) It has a plurality of pixels, the light from the light source is modulated by each pixel to generate a two-dimensional image, and the spatial frequency in the generated two-dimensional image corresponds to the plurality of diffraction orders generated from each pixel Light modulating means for emitting along the diffraction angle,
(B) Fourier transform the spatial frequency in the two-dimensional image emitted from the light modulation means to generate a number of Fourier transform images corresponding to a plurality of diffraction orders generated from the pixels, An image limiting / generating unit that selects only a predetermined Fourier transform image, and further performs inverse Fourier transform on the selected Fourier transform image to form a conjugate image of the two-dimensional image generated by the light modulation unit,
(C) an oversampling filter having a plurality of aperture regions and emitting spatial frequencies in a conjugate image of a two-dimensional image along diffraction angles corresponding to a plurality of diffraction orders generated from the respective aperture regions;
(D) Fourier transform image formation in which the spatial frequency in the conjugate image of the two-dimensional image emitted from the oversampling filter is Fourier transformed to generate a number of Fourier transform images corresponding to a plurality of diffraction orders generated from the aperture regions. means,
(E) Fourier transform image selection means for selecting a Fourier transform image corresponding to a desired diffraction order among Fourier transform images generated in a number corresponding to a plurality of diffraction orders generated from each aperture region; and
(F) conjugate image forming means for forming a conjugate image of the Fourier transform image selected by the Fourier transform image selection means;
A three-dimensional image display device comprising:
Furthermore, a transflective mirror that changes the traveling direction of the light beam emitted from the optical system,
A three-dimensional image display device. A light source and an optical system,
The optical system is
(A) It has openings arranged in a two-dimensional matrix along the X and Y directions, and generates a two-dimensional image by controlling the passage, reflection, or diffraction of light from the light source for each opening, A two-dimensional image forming apparatus that generates diffracted light of a plurality of diffraction orders for each aperture based on the two-dimensional image;
(B) a first lens in which a two-dimensional image forming apparatus is disposed on the front focal plane;
(C) a scattering diffraction limiting aperture that is disposed on the rear focal plane of the first lens and allows only diffracted light of a predetermined diffraction order to pass;
(D) a second lens in which a scattering diffraction limiting aperture is disposed on the front focal plane;
(E) P _OSF × Q _OSF arranged on the rear focal plane of the second lens and arranged in a two-dimensional matrix along the X and Y directions (where P _OSF and Q _OSF are arbitrary positive numbers) Of M) from the m-th order to the m′-th order along the X direction based on the conjugate image of the two-dimensional image generated by the second lens. (Where m and m ′ are integers, M is a positive integer), and N sets from the nth order to the n′th order along the Y direction (where n and n ′ are integers, N Is a positive integer), a sum, an oversampling filter that generates M × N sets of diffracted light,
(F) a third lens having an oversampling filter disposed on its front focal plane;
(G) A spatial filter that is arranged on the rear focal plane of the third lens and has a total of M × N opening / closing controllable openings, M in the X direction and N in the Y direction. ,
(H) a fourth lens having a spatial filter disposed on its front focal plane, and
(I) a fifth lens whose front focal point is located at the rear focal point of the fourth lens;
A three-dimensional image display device comprising:
Furthermore, a transflective mirror that changes the traveling direction of the light beam emitted from the optical system,
A three-dimensional image display device. A light source and an optical system,
The optical system is
(A) a one-dimensional spatial light modulator that generates a one-dimensional image; a scanning optical system that generates a two-dimensional image by two-dimensionally developing the one-dimensional image generated by the one-dimensional spatial light modulator; A two-dimensional image forming apparatus comprising a diffracted light generating means that is arranged on a generation surface of a dimensional image and generates diffracted light of a plurality of diffraction orders for each pixel;
(B) a first lens in which diffracted light generating means is disposed on the front focal plane;
(C) a scattering diffraction limiting aperture that is disposed on the rear focal plane of the first lens and allows only diffracted light of a predetermined diffraction order to pass;
(D) a second lens in which a scattering diffraction limiting aperture is disposed on the front focal plane;
(E) P _OSF × Q _OSF arranged on the rear focal plane of the second lens and arranged in a two-dimensional matrix along the X and Y directions (where P _OSF and Q _OSF are arbitrary positive numbers) Of M) from the m-th order to the m′-th order along the X direction based on the conjugate image of the two-dimensional image generated by the second lens. (Where m and m ′ are integers, M is a positive integer), and N sets from the nth order to the n′th order along the Y direction (where n and n ′ are integers, N Is a positive integer), a sum, an oversampling filter that generates M × N sets of diffracted light,
(F) a third lens having an oversampling filter disposed on its front focal plane;
(G) A spatial filter that is arranged on the rear focal plane of the third lens and has a total of M × N opening / closing controllable openings, M in the X direction and N in the Y direction. ,
(H) a fourth lens having a spatial filter disposed on its front focal plane, and
(I) a fifth lens whose front focal point is located at the rear focal point of the fourth lens;
A three-dimensional image display device comprising:
Furthermore, a transflective mirror that changes the traveling direction of the light beam emitted from the optical system,
A three-dimensional image display device. A light source and an optical system,
The optical system is
(A) a two-dimensional image forming apparatus having a plurality of pixels and generating a two-dimensional image based on light from a light source;
(B) An optical element having an optical power for refracting incident light and condensing it at approximately one point is arranged in a two-dimensional matrix, and has a function as a phase grating that modulates the phase of transmitted light; An optical device that emits spatial frequencies in an incident two-dimensional image along diffraction angles corresponding to a plurality of diffraction orders;
(C) Fourier transform image forming means for generating a Fourier transform image having a number corresponding to the plurality of diffraction orders by Fourier transforming a spatial frequency in a two-dimensional image emitted from the optical device;
(D) Fourier transform image selection means for selecting a Fourier transform image corresponding to a desired diffraction order among Fourier transform images generated in a number corresponding to the plurality of diffraction orders, and
(E) conjugate image forming means for forming a conjugate image of the Fourier transform image selected by the Fourier transform image selection means;
A three-dimensional image display device comprising:
Furthermore, a transflective mirror that changes the traveling direction of the light beam emitted from the optical system,
A three-dimensional image display device. A light source and an optical system,
The optical system is
(A) a two-dimensional image forming apparatus having a plurality of pixels and generating a two-dimensional image based on light from a light source;
(B) P _OD × Q _OD optical elements having an optical power that refracts incident light and collects it at approximately one point in a two-dimensional matrix along the X and Y directions (however, P _OD and Q _OD is an arbitrary positive integer) and has a function as a phase grating that modulates the phase of transmitted light. The spatial frequency in an incident two-dimensional image is changed to a diffraction angle corresponding to a plurality of diffraction orders. An optical device that emits along,
(C) a first lens in which the focal point of the optical element constituting the optical device is located on the front focal plane;
(D) A spatial filter that is arranged on the rear focal plane of the first lens and has a total of M × N open / close controllable openings, M in the X direction and N in the Y direction. ,
(E) a second lens having a spatial filter disposed on its front focal plane, and
(F) a third lens whose front focal point is located at the rear focal point of the second lens;
A three-dimensional image display device comprising:
Furthermore, a transflective mirror that changes the traveling direction of the light beam emitted from the optical system,
A three-dimensional image display device. A light source and an optical system,
The optical system is
(A) It has a plurality of pixels, the light from the light source is modulated by each pixel to generate a two-dimensional image, and the spatial frequency in the generated two-dimensional image corresponds to the plurality of diffraction orders generated from each pixel Light modulating means for emitting along the diffraction angle,
(B) Fourier transform the spatial frequency in the two-dimensional image emitted from the light modulation means to generate a number of Fourier transform images corresponding to a plurality of diffraction orders generated from the pixels, An image limiting / generating unit that selects only a predetermined Fourier transform image, and further performs inverse Fourier transform on the selected Fourier transform image to form a conjugate image of the two-dimensional image generated by the light modulation unit,
(C) a light beam traveling direction changing unit that changes a traveling direction of a light beam emitted from the image limiting / generating unit, and
(D) Imaging means for forming an image of the light beam emitted from the light beam traveling direction changing means;
A three-dimensional image display device comprising:
Furthermore, a transflective mirror that changes the traveling direction of the light beam emitted from the optical system,
A three-dimensional image display device. A light source and an optical system,
The optical system is
(A) It has openings arranged in a two-dimensional matrix along the X and Y directions, and generates a two-dimensional image by controlling the passage, reflection, or diffraction of light from the light source for each opening, A two-dimensional image forming apparatus that generates diffracted light of a plurality of diffraction orders for each aperture based on the two-dimensional image;
(B) a first lens in which a two-dimensional image forming apparatus is disposed on the front focal plane;
(C) a scattering diffraction limiting aperture that is disposed on the rear focal plane of the first lens and allows only diffracted light of a predetermined diffraction order to pass;
(D) a second lens in which a scattering diffraction limiting aperture is disposed on the front focal plane;
(E) a light ray traveling direction changing unit that is arranged behind the second lens and changes the traveling direction of the light emitted from the second lens; and
(F) a third lens that forms an image of the light beam emitted from the light beam traveling direction changing means;
A three-dimensional image display device comprising:
Furthermore, a transflective mirror that changes the traveling direction of the light beam emitted from the optical system,
A three-dimensional image display device. A light source that emits light from a plurality of light emission positions arranged discretely, and an optical system,
The optical system is
(A) A plurality of pixels, which are sequentially emitted from different light emission positions of the light source, modulate light with different incident directions by each pixel to generate a two-dimensional image, and a spatial frequency in the generated two-dimensional image A light modulating means for emitting light along a diffraction angle corresponding to a plurality of diffraction orders generated from each pixel, and
(B) A Fourier transform image in which the spatial frequency in the two-dimensional image emitted from the light modulation means is Fourier transformed to generate a Fourier transform image of a number corresponding to the plurality of diffraction orders, and the Fourier transform image is formed. Forming means,
A three-dimensional image display device comprising:
Furthermore, a transflective mirror that changes the traveling direction of the light beam emitted from the optical system,
A three-dimensional image display device. A light source that emits light from a plurality of light emission positions arranged discretely, and an optical system,
The optical system is
(A) It has openings arranged in a two-dimensional matrix along the X and Y directions, and is sequentially emitted from different light emission positions of the light source, and controls the passage or reflection of light having different incident directions for each opening. A two-dimensional image forming apparatus that generates a two-dimensional image and generates diffracted light of a plurality of diffraction orders for each aperture based on the two-dimensional image,
(B) a first lens in which a two-dimensional image forming apparatus is disposed on the front focal plane;
(C) a second lens whose front focal plane is located on the rear focal plane of the first lens; and
(D) a third lens whose front focal plane is located on the rear focal plane of the second lens;
A three-dimensional image display device comprising:
Furthermore, a transflective mirror that changes the traveling direction of the light beam emitted from the optical system,
A three-dimensional image display device.   The three-dimensional image display device according to any one of claims 1 to 9, wherein a light source and an optical system are not present on an extension of a path of a light beam whose traveling direction is changed by a transflective mirror.   The three-dimensional image display device according to any one of claims 1 to 9, wherein an image of a light source does not exist on an extension of a path of a light beam whose traveling direction is changed by a semi-transmissive mirror.   10. The three-dimensional image display device according to claim 1, wherein the three-dimensional image display device emits light from the optical system instead of including a transflective mirror that changes a traveling direction of light emitted from the optical system. A three-dimensional image display device comprising a light beam control means for changing a traveling direction of a light beam and controlling a light collecting state at an observation point of the light beam emitted from the optical system.   The three-dimensional image display device according to claim 12, wherein the light beam control means comprises a concave mirror.   13. The three-dimensional image display device according to claim 12, wherein the light beam control means includes a lens on which a light beam emitted from the optical system is incident, and a mirror on which the light beam emitted from the lens is incident. The light beam control means consists of a mirror,
The light beam control means further includes a detection means for detecting an observation point,
The three-dimensional image display device according to claim 12, wherein the position of the mirror is controlled based on the observation point detection result of the detection means. The light beam control means is composed of a lens on which the light beam emitted from the optical system is incident, and a mirror on which the light beam emitted from the lens is incident,
The light beam control means further includes a detection means for detecting an observation point,
The three-dimensional image display device according to claim 12, wherein the condensing state of the lens is controlled based on an observation point detection result of the detection means.