JP5394108B2 - 3D image display device - Google Patents

Description

  The present invention relates to a three-dimensional image display device that displays a visible image such as an image as a three-dimensional image in space.

Many methods have been proposed or developed as a method for displaying an object three-dimensionally.
As a general three-dimensional image display device, there is a binocular stereoscopic image display method (see, for example, Patent Document 1). This binocular stereoscopic image display method uses a parallax image between a left eye image and a right eye image, is equipped with polarized glasses or a polarization switching shutter, and images corresponding to each eye are displayed. This is a method of presenting each corresponding eye and displaying a three-dimensional image to an observer.
This binocular stereoscopic image display method has a feature that a three-dimensional image can be easily displayed with a relatively small amount of information. However, when a three-dimensional image is reproduced and displayed, the eyes of both eyes of the observer are displayed. Is moving or rotating, the convergence position where the line of sight intersects is different from the focal position where the lens of the eyeball is focused, causing visual fatigue (for example, 3D sickness etc.) due to this difference in position. . The problem of causing visual fatigue is a problem common to a method for producing a stereoscopic effect only by presenting a parallax image.

As a three-dimensional image display device with little visual fatigue, a method of reproducing and displaying a three-dimensional image in a space is effective, that is, a hologram display method and a depth sampling method are effective.
Among these, the hologram has a possibility of performing natural three-dimensional image display, but it requires interference fringe information of the subject, the amount of information for display is enormous, and the display is extremely high-definition. In order to display a three-dimensional image with a moving image since a display device is required, many problems remain in the amount of information and the display device (see, for example, Patent Document 2).

On the other hand, in the depth sampling method, a two-dimensional cross-sectional image at each depth position of the object (position in the distance direction between the observer and the three-dimensional image display device) is arranged in space, that is, in the depth direction. It is displayed (for example, refer to Patent Document 3).
In this method, since a 3D image having depth is displayed and reproduced in a 3D space, the convergence distance and the focal length match, and visual fatigue is compared to the above-described binocular stereoscopic image display method. In addition, the observer can observe a natural three-dimensional image according to the movement of the observation position.
This depth sampling method uses a varifocal mirror method that displays images on a vibrating mirror and displays a three-dimensional image, a moving screen method in which the screen moves mechanically at high speed, and a rotating spiral screen. There are methods.

In addition, a system that does not have a mechanical drive unit by using a liquid crystal display device has been developed. For example, a method in which a large number of liquid crystal panels are stacked and arranged in the depth direction, and an image displayed on a CRT is reflected by a panel at an appropriate depth of the stacked liquid crystal panels to display a three-dimensional image in a volumetric manner. is there.
There is also a depth sampling method using a liquid crystal with variable focal length. The images for each depth sequentially displayed on the two-dimensional display device are changed in synchronization with the focal length of the liquid crystal focus variable lens having a diameter of several centimeters or more, and each reproduced image (reproduced image) is displayed in space. ) In volume. The feature of this method is that a mechanical drive unit and special glasses worn by an observer are not required, and natural three-dimensional images can be displayed.

JP-A-8-223609 JP-A-11-103474 JP 2006-285113 A

However, the depth sampling method shown in Patent Document 3 is a time division display in which depth images are sequentially displayed in the thickness direction in a space.
Therefore, if one frame of the three-dimensional image is not completed within the afterimage time of the observer's eyes, that is, if all the two-dimensional images in the depth direction are not displayed, flicker lacking the image will be perceived.
On the other hand, when the display time of one cross-sectional image (two-dimensional image) is shortened, the luminance of the image is lowered and a clear three-dimensional image cannot be obtained.
Further, the conventional depth sampling method requires a special display device that displays a large number of cross-sectional images at high speed in the depth direction within the video rate time of the moving image.

Further, there is an integral photography method shown in FIG. 19 as a method for reproducing a three-dimensional image in a space without using time division. In this integral photography method, in photographing, a subject is photographed through a minute lens array to obtain an element image. Then, in the display in the integral photography system, the element image 210 is displayed, and the reproduction light 212 is observed through the lens array 211, so that the observer 213 can observe the reproduction three-dimensional image 214.
This integral photography system is characterized in that an elemental image can be taken in real time, and a three-dimensional image can be reproduced and displayed by this elemental image, and the possibility as a three-dimensional television is high.

Further, the integral photography system does not require special glasses used in the above-described binocular stereoscopic image display system, and has parallax both in the horizontal direction and in the vertical direction. In addition, since the integral photography method is an aerial image reproduction method, it is possible to display a natural three-dimensional image similar to the actual observation.
However, as shown in FIG. 20, the integral photography system is generally installed such that the distance between the element image 221 and the lens array 222 is approximately the same as the focal length g · 223 of the lens array 222. ing. The focal length of each lens constituting the lens array 222 in this figure is g.
In the optical arrangement in FIG. 20 described above, light from the element image is output from each lens array 211 in a form close to parallel rays.

For this reason, an image is reproduced at a certain depth position from the surface of the lens array 222 by the intersection position of parallel rays from the element image, and the spatial resolution of the reproduced image is limited by the size of each lens of the lens array 222 (see FIG. 20 (a) to (c)). Therefore, the only way to improve the resolution with the conventional integral method is to reduce the size of the lens array. However, this requires technically difficult technical development such as miniaturization of the pixels of the element image 221 and further miniaturization of the size of the lens array 222.
In particular, if the lens size is further refined to a sub-mm order diameter, the influence of light diffraction increases, and the light emitted from the lens tends to be diffused light rather than parallel light. There is a limit to miniaturization of the lens size.

Furthermore, in reality, the pixel of the element image has a finite size, and the light emitted from the display element corresponding to the pixel is generally not coherent light. I can't.
Due to the above-described characteristics, the resolution is different between the vicinity of the lens array 222 surface and the vicinity of the lens array 222 surface as shown below.
That is, when the reconstructed image is on or near the lens array surface, as shown in FIG. 20A, the error at the intersection of the corresponding pixels in each element image is small, so the resolution is defined by the spatial frequency of the lens. Images can be played back.
On the other hand, in the three-dimensional video behind the lens array 222 and the three-dimensional video jumping out toward the front, the error of the intersecting portion of the corresponding pixels in each element image becomes large, and therefore FIG. 20B and FIG. As shown in c), the pixels are blurred and the resolution is deteriorated.

  The present invention has been made in view of such circumstances, and an object of the present invention is to reproduce each 3D image at any depth position when reproducing a 3D image in a spatial image reproduction system using a lens array. An object of the present invention is to provide a three-dimensional image display device capable of suppressing the occurrence of pixel blur as compared with the conventional method.

[1] The present invention has been made to solve the above-described problems, and a three-dimensional image display device according to an aspect of the present invention provides corresponding pixels in a plurality of element images that are two-dimensional planar images in a three-dimensional space. Is a three-dimensional image display device of an integral photography system that displays a three-dimensional image by superimposing in FIG. 2, and a plurality of display elements are arranged, and the display elements are divided into a plurality of divided regions for displaying the element image. A two-dimensional image display unit, a variable-focus lens disposed on the optical axis of each display element in the two-dimensional image display unit, and each divided region on the light emission side of the variable-focus lens. respectively the lens disposed at a position overlapping, corresponding to the coordinate position of the three-dimensional space of the pixels of the 3D image, on the each display element in the two-dimensional image display unit, By controlling the focal length of the variable focus lens corresponding to the display element, the light emitted from the front Symbol display device of the plurality of divided areas constituting the pixels of one of the 3-dimensional image, wherein And a display control unit for focusing light by the lens at the same position in a three-dimensional space .
Here, the light that is emitted from the display element in each divided region of the two-dimensional image display unit is the light that is emitted from the display element at the pixel position corresponding to the element image in each divided region, and the variable focus lens corresponding to the display element. Thus, the element image can be three-dimensionally displayed in the space by focusing on the pixel position of the three-dimensional image to be reproduced in the space. In addition, since the light of the corresponding pixels between the element images is condensed and synthesized at the light condensing point to be the pixels, the pixels are not enlarged compared to the case of using the conventional parallel light, and the pixels are fine. Pixels can be formed, and a clear three-dimensional image can be displayed. Further, since the light is condensed from the display element corresponding to each of the plurality of divided regions with respect to the pixel position of the three-dimensional image, the viewing angle (the region where the reproduced image can be seen is shown) as compared with the conventional case. (Angle) becomes larger, and the range in which the three-dimensional image can be observed can be expanded.

[2] In the three-dimensional image display device according to one aspect of the present invention, the display element in the two-dimensional image display unit is formed of a light emitting element that is a point light source having a diameter smaller than a grid interval corresponding to a set resolution. It is characterized by being.
Here, the size of the point light source only needs to be smaller than a pixel that provides the resolution of the three-dimensional image displayed in the space. The pixels of the three-dimensional image that are collected by the variable focus lens and formed by superimposing the pixels of the plurality of element images can be displayed in a size that is less than the resolution of the three-dimensional image. I can plan.

[3] In the three-dimensional image display device according to one aspect of the present invention, the two-dimensional image display unit can be regarded as a point light source having a diameter smaller than the grid interval corresponding to the set resolution, and a transmission type or a reflection type. And a display element array in which display elements that modulate light from the light emitting portion are arranged.
Here, the size of the point light source only needs to be smaller than a pixel that provides the resolution of the three-dimensional image displayed in the space. The pixels of the three-dimensional image that are collected by the variable focus lens and formed by superimposing the pixels of the plurality of element images can be displayed in a size that is less than the resolution of the three-dimensional image. I can plan.

[4] In the three-dimensional image display device according to one aspect of the present invention, the divided region, the variable focus lens provided corresponding to the display element of the divided region, and the position overlapping the divided region in plan view And the display control unit that adjusts the variable focus lens corresponding to the divided area are configured as one display module.
There is no need to produce a two-dimensional image display portion with a large area, and the miniaturization of the display element of the two-dimensional image display portion can be improved, and the resolution can be further increased.
Also, by increasing the number of modules, the number of pixels of the element image can be increased, and the reproduction stereoscopic image can be increased in number of pixels (high definition) and wide viewing area. Furthermore, by arranging a large number of modules, a large display can be constructed, and a large-screen stereoscopic image can be displayed.
In addition, since the two-dimensional image display unit is manufactured for each divided region, the cost of parts that cannot be used when any of the display elements becomes defective can be reduced, and the manufacturing cost of the three-dimensional image display device can be reduced. Can be reduced.

[5] In the three-dimensional image display device according to one aspect of the present invention, a plurality of point light sources are provided for the variable focus lens, and the position of the pixel of the three-dimensional image is determined according to which point light source is used. Control is performed on a two-dimensional plane parallel to the display unit.
Here, as for the position of the pixel of the three-dimensional image, the depth position of the reproduced image is determined by the position of the display element in the divided area. Finer three-dimensional images can be displayed by fine-tuning the position in the dimensional plane.

[6] In the three-dimensional image display device according to one aspect of the present invention, the display control unit has the same preset focal length of all the variable focus lenses corresponding to the display elements of the two-dimensional image display unit. By setting the value, the position of the condensing point by the variable focus lens is a two-dimensional display plane parallel to the two-dimensional image display unit at a predetermined distance from the lens, and the image displayed on the two-dimensional image display unit and characterized in that to be displayed on the two-dimensional display plane.
Like a normal television receiver, a two-dimensional plane image can be displayed, and both a two-dimensional image and a three-dimensional image can be viewed on a single television.

[7] The three-dimensional image display device according to an aspect of the present invention further includes a diffusion screen that is disposed at the position of the two-dimensional display plane and switches between a transparent state that transmits light and a state that diffuses light. When displaying a three-dimensional image, the diffusion screen is in a transparent state that transmits light, and when displaying a two-dimensional image, the diffusion screen is in a state of diffusing light.
Like a normal television receiver, a two-dimensional plane image can be displayed, and both a two-dimensional image and a three-dimensional image can be viewed on a single television.

  According to the present invention, a variable focus lens capable of controlling the focal length is disposed for each display element of the two-dimensional image display unit, and a lens or a lens array is disposed in front of the variable focus lens array. Therefore, when reproducing a three-dimensional image in space, the focal length of each of the variable focus lenses is individually controlled so that the light from the display element is condensed at an arbitrary depth position in the space corresponding to the pixel position. Thus, the parallel light is not blurred and the crossing position is not shifted as in the conventional case, and the three-dimensional image can be displayed more finely than in the conventional case.

1 is a block diagram illustrating a configuration example of a three-dimensional image display device according to a first embodiment of the present invention. FIG. 2 is a plan view illustrating a configuration example of a two-dimensional image display element 11 in FIG. 1. It is a conceptual diagram explaining the operation | movement in which the three-dimensional image display apparatus of FIG. 1 forms each pixel of a three-dimensional image in space. It is a conceptual diagram explaining the control of the display coordinate which displays the pixel with respect to the z direction of the space in the three-dimensional image display apparatus of FIG. 6 is a graph showing a relationship between a variable focal distance of the variable focus lens 22 and a condensing distance L of light from the fixed focus lens 23. It is a conceptual diagram explaining the pixel formation process of the three-dimensional image by the display control part 10 of FIG. 1 in the three-dimensional coordinate of space. It is a conceptual diagram explaining the viewing zone angle in the conventional three-dimensional image display apparatus. It is a conceptual diagram explaining the viewing zone angle in the three-dimensional image display apparatus of this embodiment. It is a conceptual diagram which shows the structural example of the three-dimensional image display apparatus by 2nd Embodiment of this invention. It is a conceptual diagram which shows the other structural example of the three-dimensional image display apparatus by 2nd Embodiment. It is a conceptual diagram which shows the structural example of the three-dimensional image display apparatus by the 3rd Embodiment of this invention. It is a conceptual diagram which shows the other structural example of the three-dimensional image display apparatus by 3rd Embodiment. It is a conceptual diagram which shows the other structural example of the three-dimensional image display apparatus by 3rd Embodiment. It is a conceptual diagram which shows the structural example of the three-dimensional image display apparatus by the 4th Embodiment of this invention. It is a conceptual diagram which shows the structural example of the three-dimensional image display apparatus by the 5th Embodiment of this invention. It is a conceptual diagram which shows the other structural example of the three-dimensional image display apparatus by 5th Embodiment. It is a conceptual diagram which shows the other structural example of the three-dimensional image display apparatus by 5th Embodiment. It is a conceptual diagram which shows the other structural example of the three-dimensional image display apparatus by 5th Embodiment. It is a conceptual diagram explaining the three-dimensional image display apparatus by the conventional integral photography system. It is a conceptual diagram explaining the pixel display in the three-dimensional image by the three-dimensional image display apparatus by the conventional integral photography system.

<First Embodiment>
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic block diagram illustrating a configuration example of the three-dimensional image display apparatus according to the present embodiment.
The three-dimensional image display apparatus according to the present embodiment is a two-dimensional structure in which a display control unit 10 that controls display coordinates of pixels of a three-dimensional image in space and a plurality of display elements 21 are arranged on a two-dimensional plane. The image display unit 11, a variable focus lens array 12 configured by arranging a plurality of variable focus lenses 22 having variable focal lengths on a two-dimensional plane, and a fixed focus lens having a fixed focus on a two-dimensional plane. A plurality of fixed focus lens arrays 13 arranged in a row. In the following description, the y-axis of the three-dimensional space is the vertical direction of the drawing, the z-axis is the horizontal direction of the drawing, and the x-axis is the vertical direction with respect to the plane formed by the y-axis and the z-axis.
Here, the two-dimensional image display unit 11, the variable focus lens array 12, and the fixed focus lens array 13 are arranged so that their two-dimensional planes are parallel to each other.

In the present embodiment, for each display element 21 (corresponding to a pixel of a two-dimensional image) of the two-dimensional image display unit 11 that displays an image, a variable focus lens 22 that can change the focal length on the optical axis is overlapped. The two-dimensional image display unit 11 and the variable focus lens array 12 are arranged in parallel. Corresponding to image data (x, y, z), which is input when displaying a three-dimensional image, and indicating the coordinate position of the space for displaying each pixel, the display control unit 10 in the two-dimensional image display unit 2 Is selected, the focal length of the variable focal lens 22 is controlled, and the variable focal lens 22 condenses the pixels of the three-dimensional image in the space to display the reproduced image.
As shown in the plan view of FIG. 2 (plan view seen from the z-axis direction of FIG. 1), the display elements 21 in the two-dimensional image display unit 11 are arranged in a grid on the two-dimensional plane. In order to display an element image, which is a two-dimensional image for forming a three-dimensional image, in the three-dimensional space, there are a plurality of display elements 21 in the two-dimensional image display unit 11, and in this embodiment, 225 display elements. 21 is divided into nine groups of divided regions B1 to B9 as 25 groups. A cross section taken along line AA in FIG. 2 corresponds to the two-dimensional image display unit 11 in FIG. The fixed-focus lens array 13 is placed at a predetermined distance from the variable-focus lens array 12 so that one fixed-focus lens 23 overlaps the one divided area composed of each display element 21 in a plan view (z-axis direction). The light is emitted from the variable focus lens array 12 on the side from which light is emitted.
With the configuration described above, the light emitted from each display element 21 of the two-dimensional image display unit 11 passes through the variable focus lens array 12 and the fixed focus lens array 13, so that a reproduced image 14 that is a three-dimensional image in space is obtained. Generated. In the present embodiment, a description will be given assuming that a set of pixels in space forms a three-dimensional reproduced image to be displayed.
2 has been described with the configuration in which the divided regions are arranged in a square lattice shape. For example, the divided regions are formed as a configuration in which the divided regions are arranged in a stacked (delta arrangement) shape or a polygonal shape. Also good. Note that the number of pixels in the horizontal direction of the divided area corresponds to the number of parallaxes in the horizontal direction, and the number of pixels in the vertical direction corresponds to the number of parallaxes in the vertical direction. In this divided area, the number of pixels in the horizontal direction need not be equal to the number of pixels in the vertical direction. For example, when the number of parallaxes in the horizontal direction is increased, the number of pixels in the vertical direction may be decreased and the divided region may be increased in the number of pixels in the horizontal direction. On the other hand, when the number of parallaxes in the vertical direction is increased, the number of pixels in the horizontal direction may be decreased and the divided region may be increased in the number of pixels in the vertical direction. Of course, only the pixels in the horizontal direction or the pixels in the vertical direction may be used.
The fixed-focus lens array can use not only a general round circular lens but also various shapes of lenses according to the shape of the element image. For example, if the number of pixels in the element image is different from the vertical, the horizontal Lenses with different direction and longitudinal curvatures can also be used. Further, in the case of an element image having only horizontal pixels, a cylindrical lens can be used as the fixed focus lens.

The two-dimensional image display unit 11 includes a configuration in which each display element 21 modulates light from an external point light source such as a liquid crystal panel or DMD (Digital Micromirror Device), a CRT (Cathode Ray Tube), or a PDP (Plasma Display Panel). A display panel having a display element 21 of a self-luminous type such as EL (Electro Luminescence), FED (Field Emission Display), LED (Light Emitting Diode), etc. (in this case, the display element itself becomes a point light source) is used. be able to. Here, the size of the point light source is a size having a diameter smaller than the grid interval corresponding to the set resolution of the three-dimensional image. Thereby, when the light is condensed by the variable focus lens 22, pixels smaller than the grid interval can be formed.
Although details will be described later, as the variable focus lens 22 constituting the variable focus lens array 12, for example, liquid crystal is used, or an electrowetting technique (a small amount of oil and water, and applying a voltage from hydrophobic to hydrophilic). It is possible to use a method of electrically controlling the shape of the liquid, such as a display element formed of a layer of a changing material.

Next, the principle of displaying a three-dimensional image according to the present embodiment will be described with reference to FIG. FIG. 3 is a conceptual diagram for explaining display processing of pixels of a three-dimensional image with respect to a space.
Light that forms pixels is emitted from the display elements 21 in the divided regions B1 to B9 that contribute to the reproduction of the three-dimensional image to the variable focus lens 22 corresponding to the display elements 21. The light forming this pixel passes through each of the variable focus lenses 22 and is further condensed by the fixed focus lens 23 at a position in the z-axis direction of the image data in space to form a pixel of a three-dimensional image. At this time, in each of the divided regions B1 to B9, one display element 21 is condensed at the same coordinate position in the three-dimensional coordinates, and the coordinate position where the light emitted from the nine display elements 21 is collected is used as a pixel. A three-dimensional image is displayed. Here, in each of the divided regions B1 to B9 of the two-dimensional image display unit 11, in order to form a reproduced image that is a three-dimensional image, a similar element image that is a two-dimensional image is displayed.

As will be described later, the positions of the pixels 32, 33, and 34 in the three-dimensional space are set based on the position of the display element 21 in the divided areas B1 to B9 and the focal length of the variable focus lens 22. That is, the light from the element image displayed on the two-dimensional image display unit 11, that is, the light from the display element 21 displaying the element image is controlled by the variable focus lens 22, and the fixed focus It passes through the lens 23 and is most condensed at a depth position (coordinate position of the pixel 33) corresponding to the control of the light condensing property of the variable focus lens 22.
When the image is reproduced at a coordinate position closer to the pixel 33, the position of the display element 21 in the divided area of the two-dimensional image display unit 11 is changed, and the focal length of the variable focus lens 22 is compared with that of the pixel 33. Thus, the pixel 34 is displayed at a coordinate position closer to the surface of the fixed focus lens array 13 than the distance of the pixel 33.
In the case of reproducing an image at a coordinate position far from the coordinate position of the pixel 33, the position of the display element 21 in the divided area of the two-dimensional image display unit 11 is changed, and the focal length of the variable focus lens 22 is changed to the pixel 33. By making the length longer than, the pixel 32 is displayed at a coordinate position farther from the surface of the fixed focus lens array 13 than the distance of the pixel 33.

Therefore, by individually controlling the focal length of the variable focus lens for each of the display elements 21 that display the element image, the pixels are condensed at arbitrary depth positions for each pixel of the three-dimensional image, A three-dimensional image can be formed.
In the case of the present embodiment, the light from the plurality of display elements 21 is collected at the coordinate position of the pixel by condensing (narrowing) the light from the corresponding display elements 21 of the divided regions B1 to B9 at the same coordinate position. Thus, since one pixel of the three-dimensional image is displayed, the spatial resolution (spatial resolution) can be increased without spreading light as in the prior art.
When attention is paid to the light beam output from one fixed focus lens, the light is focused on each pixel at the imaging position of the three-dimensional image. The point that the focus adjustment of the eye functions also differs from the conventional method because stereoscopic fatigue can be suppressed.

Next, a method for controlling the coordinate position in the z-axis direction in the three-dimensional image display apparatus according to the present embodiment will be described with reference to FIG. FIG. 4 is a conceptual diagram illustrating the relationship between the focal length controlled by the variable focus lens 22 and the coordinate positions of pixels displayed in space. Here, each display element 21 of the two-dimensional image display unit 11 emits light 41 as parallel light to the variable focus lens 22, and the light 41 enters the variable focus lens 22 as parallel light. explain. The focal length f of the variable focus lens 22 is controlled by pixel data (x, y, z) of each elemental image input to the display control unit 10 in FIG.
As shown in FIG. 4A, the focal length of the variable focus lens 22 is f, the focal length g of the fixed focus lens 23, and the distance between the variable focus lens 22 and the fixed focus lens 23 is f + g.
At this time, the parallel light beam 41 from the element image is output as the output light 42 which is a parallel light beam even after passing through the fixed focus lens 23.

Further, as shown in FIGS. 4B and 4C, when the focal length of the variable focus lens 22 is changed from f to f ′ = f−Δf, after passing through the fixed focus lens 23, the light of the pixel is transmitted. The distance L to the condensing point 43 is obtained by the following equations (1) and (2).
1 / (g−Δf) + 1 / L = 1 / g (1)
L = −g (g−Δf) / Δf (2)
Here, in the case of FIG. 4B, the focal length is shortened from f to f−Δf (Δf <0), and in the case of FIG. 4C, the focal length is changed from f to f−Δf (Δf>). 0).
As an example of the relationship between the focal length in FIG. 4 and the distance L from the fixed focus lens 23 to the light condensing point 43 (the coordinate value of the pixel displayed in the space), FIG. And a graph showing the relationship with the distance L. In FIG. 5, the focal length of the fixed focus lens 23 is set to g = 5.24 mm. Here, when Δf is changed from 0 to 1 mm, the distance L changes from ∞ to 22.2 mm, while when Δf is changed from 0 to −1 mm, the distance L changes from ∞ to −22.2 mm. And change.
Therefore, as shown in FIG. 5, when the distance between the variable focus lens 22 and the fixed focus lens 23 is f + g, Δf is controlled around the focal length g, and the focal length f ′ of the variable focus lens 22 is adjusted. Thus, the position in the z-axis direction can be controlled in a wide depth range.

Next, a method for controlling the coordinate position of the pixel on the two-dimensional plane of the x-axis and the y-axis in the three-dimensional image display apparatus according to this embodiment will be described with reference to FIG. FIG. 6 is a conceptual diagram for explaining pixel formation processing of a three-dimensional image by the display control unit 10 of FIG. 1 at three-dimensional coordinates in space.
As shown in FIG. 6, the relationship between the focal length and the lens position of the variable focus lens 22 and the fixed focus lens 23 when the reproduced image 61 is reproduced at coordinates (x, y, z) is shown. The focal length f ′ of the variable focus lens 22 is f + Δf, the lens center coordinates are (x _e , y _e , −g−f), and the focal point coordinates of the variable focus lens 22 are (x _e , y _e , −g + Δf). And However, at this time, the position of the element image and the center position coordinate of the variable focus lens 22 are assumed to be equal. The focal length of the fixed focus lens 23 is g, and the center coordinates of the fixed focus lens 23 are (x ₀ , y ₀ , 0). Assume that the variable focus lens 22 and the fixed focus lens 23 are arranged at a distance of g + f. The coordinates (0, 0, 0) are the coordinates of the display element at the center of all the display elements of the two-dimensional image display unit 11.

The coordinates (x, y, z) of the reproduced image 61 under the above conditions are expressed by the following equations (3) to (5).
x = x ₀ + (x _e −x ₀ ) · g / Δf (3)
_{y = y 0 + (y e} -y 0) · g / Δf ... (4)
z = −g · (g−Δf) / Δf (5)
From the formulas (3) to (5), in order to reproduce the reproduced image at the coordinates (x, y, z), the variable amount Δf of the focal length of the variable focus lens 22 is changed to the above formula (5). The following equation (6) is obtained and set.
Δf = −g ² / (z−g) (6)

Further, the position of the variable focus lens 22 for reproducing the reproduction image at the coordinates (x, y, z), that is, the coordinate position of the display element 21 in the two-dimensional image display unit 11 is expressed by the following equations (7) and (8). ) To determine and set.
x _e = x ₀ + −g · (x−x ₀ ) / (z−g) (7)
y _e = y ₀ + −g · (y−y ₀ ) / (z−g) (8)
Therefore, the display control unit 10 uses the coordinate position (x, y, z) in the space of each pixel of the input image data as the coordinate position of each pixel of the reproduced image 61 to be displayed in the three-dimensional space. The distance variable amount Δf and the coordinate position of the display element 21 in the two-dimensional image display unit 11 are calculated, and the two-dimensional image display unit 11 and the variable focus lens array 12 are controlled so that the reproduced image 61 is displayed in space. To do.

Next, the viewing zone angle of the three-dimensional image in the conventional example and this embodiment will be described. As shown in FIG. 7, in a conventional three-dimensional image display system using a variable focus lens (Japanese Patent Application Laid-Open No. 2004-144874), the variable focus lens 22 corresponding to each of the display elements 21 causes the display element 21 to move away from the display element 21. The emitted light is imaged, and the pixels in the three-dimensional reproduced image are displayed in the air.
However, in the method of FIG. 7, there is a relationship represented by the following formula (9) and the viewing zone angle θ at which the 3D video reproduced in the air can be observed and the depth pop-out amount f ′.
θ = 2arctan (D / 2f ′) (9)
In the above formula (9), the pop-out amount f ′ is the variable focal length of the variable focus lens 22, D is the diameter of the variable focus lens 22, and is the same as the aperture diameter of the surface of the display element 21 that emits light. It is.

As can be seen from the above equation (9), the viewing zone angle θ at which the observer can observe a three-dimensional image and the depth protrusion amount f ′ (that is, the variable focal length of the variable focus lens 22) are a trade-off. There is a problem that the viewing zone angle θ is limited to be narrow when the protrusion amount of the depth (the display depth of the image) is increased.
That is, in Expression (9), the diameter D of the display element 21 is sub-μm, but if the projection amount f ′ is increased to increase the depth, the viewing zone angle θ is reduced, and a position where a three-dimensional image can be observed. (Angle range) will be limited.

Therefore, in the present embodiment, as shown in FIG. 8, the focal position of the variable focus lens is adjusted for each corresponding display element, and a plurality of fixed focus lenses 23 constitutes a pixel of the reproduced image and reproduces it. . That is, each pixel in the three-dimensional reproduced image displayed in space is imaged by the fixed focus lens 23 corresponding to the light emitted from the plurality of display elements 21, so that the plurality of imaged light is used. Is formed.
For this reason, the viewing zone angle θ ′ of the pixel in the present embodiment is expressed by the following equation (10).
θ ′ = 2arctan (D ′ / 2L)
= 2 arctan [D′ Δf / {2 g · (g−Δf)] (10)
In the above equation (10), g is the focal length of the fixed focus lens 23, Δf is the variable amount of the focal length of the variable focus lens 22, and D ′ is the effective diameter of the fixed focus lens array 13 (constituting the fixed focus lens array 13). It is a numerical value obtained by adding the diameter of the fixed focus lens 23).

From the above formula (10), the effective diameter D ′ of the fixed focus lens array 13 can be increased by increasing the number of fixed focus lenses 23 in the fixed focus lens array 13 that contribute to the formation of each pixel in the reproduced image.
This is equivalent to increasing the number of pixels (that is, the number of display elements) of the element image that contributes to the reproduction of one pixel in the three-dimensional reproduced image. Therefore, although the number of pixels of the three-dimensional video that is a reproduced image is reduced, a wide viewing zone can be secured.
It should be noted that the number of pixels of the element image and the number of fixed focus lenses necessary for reproducing the reproduced image are adjusted according to Δf so as to ensure the necessary viewing zone angle θ ′ according to the equation (10). The number of pixels of the two-dimensional image (that is, the number of display elements 21 of the two-dimensional image display unit 11) can be used efficiently, and a high-quality reproduced image can be obtained.

Next, the variable focus lens 22 used in this embodiment will be described. A variable focus lens using a liquid crystal element can be used as the variable focus lens 22. Therefore, a liquid crystal display is used as the variable focus lens array 12. As an example of the variable focus lens using this liquid crystal element, a transparent electrode is laminated on a transparent substrate, and the two transparent substrates on which the transparent electrode is laminated are opposed to each other so as to have a space of a predetermined distance. What fills the space with liquid crystal can be used. As a material for the transparent substrate, for example, glass, a polymer film, or the like can be used. As the transparent electrode, a transparent conductive thin film such as an ITO (Indium-Tin Oxide) film in which tin (Sn) is doped in an indium oxide (In ₂ O ₃ ) film can be used.
In the transparent electrode of the opposing transparent substrate configured as described above, the alignment characteristics of the liquid crystal molecules in each liquid crystal element are determined by the structure in which a hole without a transparent electrode is opened in the center of one side or both sides of each liquid crystal element. Unlike the central portion and the peripheral portion of the element, it is possible to have a refractive index distribution corresponding to the lens function.

The variable focus lens can also be formed by giving a spatial distribution to the alignment treatment of the liquid crystal molecules by the alignment film applied to the opposing transparent substrate. The alignment film controls the alignment direction of liquid crystal molecules in each liquid crystal element. As the material of this alignment film, when the transparent substrate is glass, for example, a polymer film such as SiO ₂ , polyimide, or polyvinyl alcohol (PVA) can be used, and the transparent substrate can be a polymer film or the like. In this case, modified PVA, nylon epoxy-organic titanium, or the like can be used.
As the above alignment treatment method, rubbing alignment treatment by rubbing the alignment film surface in one direction with cloth, photo-alignment method, oblique vapor deposition method, method using stretched polymer film, grating method, external field application Method, temperature gradient method, etc. can be used. By these alignment treatments, the liquid crystal molecules are anchored to the substrate, and the directionality of the liquid crystal molecules in the liquid crystal element can be controlled three-dimensionally.

  At least one of the alignment films or the alignment films described above is different in the alignment treatment depending on the location. That is, the direction in which the liquid crystal molecules are anchored to the alignment film (regulation of the alignment of the liquid crystal molecules) is changed depending on the location, and the change is a diffraction grating having a periodic structure, for example, a Fresnel zone plate shape or a cylindrical lens shape. . As a liquid crystal used in this case, a nematic liquid crystal, a cholesteric liquid crystal, a smectic liquid crystal, a ferroelectric liquid crystal, a dual frequency drive type liquid crystal, or a mixed liquid crystal of these liquid crystals is used. The difference in the alignment of the liquid crystal molecules is a difference in refractive index with respect to light passing through the portion subjected to the alignment treatment due to the birefringence characteristics of the liquid crystal molecules, and a phase type diffraction grating is obtained. Since the diffraction pattern is a Fresnel zone plate shape or a cylindrical lens shape, it becomes a diffractive lens, and the light transmitted through the portion subjected to the orientation treatment is collected.

In addition to the liquid crystal element described above, an element having the function of a variable focus lens by changing the shape of the liquid can also be used.
For example, by adjusting the applied voltage between the liquid and the substrate, such as an electrowetting element (a lens element that uses the electrowetting phenomenon to control the curvature of the liquid lens), the contact angle between the liquid and the substrate surface is controlled, and the liquid lens A method of controlling the curvature of the image can also be used.
Furthermore, an element that mechanically moves an element such as a lens or a pinhole in the z-axis direction (depth direction) at high speed, and an element that transparently changes the focal length can be used.
Also, as this variable focus lens, an optical element that makes the focal length variable by deforming a lens formed of glass or gel-like liquid by a polymer actuator (piezoelectric actuator) formed of a polymer or the like Can also be used.
As the variable focus lens described above, a lens having any shape such as a circular shape or a square shape can be used. Further, a lens in which the control direction of the focal length of the lens is only one direction, that is, a so-called cylindrical lens may be used.
A combination of the above-described variable focus lens and a normal fixed focus lens can also be used as the variable focus lens of the present embodiment. In general, the variable focus range of the variable focus lens is limited by the performance and configuration of the device, the drive voltage for controlling the focal length, and the like. For this reason, the focus variable range can be adjusted by using a combination of a normal fixed focus lens and a variable focus lens.

<Second Embodiment>
Next, a second embodiment of the present invention will be described with reference to the drawings. FIG. 9 is a schematic block diagram illustrating a configuration example of the three-dimensional image display device according to the present embodiment. In the configuration of the second embodiment, the same components as those of the first embodiment shown in FIG. The configuration and operation of the second embodiment different from those of the first embodiment will be described below.
As described in the first embodiment, since the element image is displayed corresponding to each fixed focus lens 23 of the fixed focus lens array 13, the number of fixed focus lenses 23 is the number of pixels of the three-dimensional image, that is, the resolution. It becomes. Therefore, the two-dimensional image display unit 11 needs to have many display elements in order to obtain a high-definition reproduced image, that is, to form pixels.

For the reason described above, when one two-dimensional image display unit 11 is configured by a single flat display, the number of pixels of the reproduced image is insufficient when reproducing a fine three-dimensional reproduced image. Therefore, as shown in FIG. 9, the two-dimensional image display unit 11 is used for each fixed focus lens 23 in the fixed focus lens array 13, that is, the divided regions (B1 to B1) shown in FIG. You may comprise as the display block 100 for every B9).
Each of the microdisplays 91 is provided with a microdisplay driving circuit 92 (for controlling the focus of the display element 21 and the variable focus lens 22), and is configured to be able to display an image independently.

The video displayed on each micro display 91 is phase-adjusted by an external synchronization signal 93 output from the display control unit 10 (not shown) (that is, synchronized).
Further, the display control unit 10 receives the coordinates of each pixel of the reproduced image to be displayed in the three-dimensional coordinates of the space from the coordinate position (x, y, z) of each pixel in the image data input from the external device. As the position, the variable amount Δf of the focal length and the coordinate position of the display element 21 in the micro display 91 are calculated.
Then, the display control unit 10 transmits the coordinate position of the display element and the variable amount Δf of the focus variable lens 22 corresponding to each display element to the micro display 91 corresponding to the coordinate position of the display element 21, and displays it. An external synchronization signal 93 is output at the timing.
Each micro display driving circuit 92 controls the display element 21 corresponding to the coordinate position and the focus variable lens 22 corresponding to the display element based on the coordinate position of the input element image on the micro display 91 and the variable amount Δf. Control is performed for each display element 21 of the micro display 91.

  Then, the light emitted from the display element 21 in the micro display 91 is coupled to a space as a pixel of a reproduced image of the three-dimensional image through the variable focus lens 22 and the fixed focus lens 23 as in the first embodiment. Imaged. Similarly to the first embodiment, each pixel of the two-dimensional image displayed on the micro display 91 corresponds to each fixed focus lens 23, and the light emitted from the display element 21 is used as a pixel in space. An image is formed, and a three-dimensional reproduced image is displayed by pixels in a space formed by a plurality of pixels of the two-dimensional image.

As described above, in the present embodiment, a configuration in which one fixed focus lens 23 corresponds to one micro display 91 can be used.
With this configuration, the difference in the image quality of the display image for each micro display 91 (such as variations in the position of the display element between the micro displays 91) can be corrected as unevenness for each fixed-focus lens when a three-dimensional image is displayed. It is possible to suppress the deterioration of the image quality of the reproduced three-dimensional reproduced image.

Further, as described above, when the two-dimensional image display unit 11 is configured using a plurality of microdisplays 91, that is, the number of microdisplays 91 corresponding to the number of fixed focus lenses 23, the gaps between the microdisplays 91 are corrected. There is a need.
In this case, as shown in FIG. 10, the light emitted from each display element of the micro display 91 discretely arranged two-dimensionally is changed in focus by the variable focus lens array 12 via the relay imaging optical mechanism 101. The lens 22 is configured to be input. With this configuration, the variable focus lens array 12 can have a lens array structure in which the variable focus lens 22 is arranged without a gap, as in the first embodiment.

That is, the relay imaging optical mechanism 101 is composed of a plurality of lenses, and the light emitted from each display element 21 in the micro display 91 to each of the variable focus lenses 22 of the variable focus lens array 12 is Optical paths to be input to the corresponding variable focus lenses 22 are configured.
As an example of the relay imaging optical mechanism 101 described above, a telecentric 4f imaging optical system can be used. As a result, the element image displayed on the micro display 91 is converted into an image with little distortion, and the light emitted from each display element 21 can be accurately input to the corresponding variable focus lens 22 in the variable focus lens array 12. it can.

<Third Embodiment>
Next, a third embodiment of the present invention will be described with reference to the drawings. FIG. 11 is a schematic block diagram illustrating a configuration example of the three-dimensional image display device according to the present embodiment. The third embodiment relates to the arrangement of the two-dimensional image display unit 11 and the variable focus lens array 12 between the point light source 110 and the fixed focus lens array 13, and other configurations and operations are described in the first embodiment and The configuration and operation are the same as those of the second embodiment.
In the present invention, between the point light source 110 and the fixed focus lens array 13, the arrangement relationship between the variable focus lens array 12 and the two-dimensional image display unit 11 may be either on the fixed focus lens array 13 side. good.
That is, as described in the first and second embodiments already described, is there a variable focus lens array 12 after the two-dimensional image display unit 11 in the traveling direction of the light from the point light source 110? Alternatively, as shown in FIG. 11, a point light source 110 is arranged, a variable focus lens array 12 is arranged in the next stage, and a two-dimensional image display unit 11 of a type that modulates light like a liquid crystal element is arranged in the next stage. The fixed focus lens array 13 may be arranged at the next stage.

  In the case of the arrangement shown in FIG. 11 described above, the point light sources 110 may be arranged at a rate of one for each pixel of the variable focus lens 22 and the two-dimensional image display unit 11. Here, as the point light source 110, when the diameter of the light emitting element is smaller, the condensing point 111 can be made smaller, so that light emitted from the plurality of display elements 21 is imaged in the space. In this case, the size of the pixel formed by forming a plurality of light images can be further reduced, which is effective for improving the resolution of the reproduced image. For example, the diameter of the point light source 110 needs to be sufficiently smaller than the diameter of the display element 21.

In addition, as shown in FIG. 12, an illumination optical system 120 that converts light into parallel light after the point light source 110 may be provided for each display element 21 between the point light source 110 and the variable focus lens array 12. .
Then, the illumination optical system 120 converts the light emitted from each point light source 110 into parallel light, which is input to the display element 21 corresponding to the illumination optical system 120 in the two-dimensional image display unit 11. According to this configuration, the light emitted after being modulated by the display element 21 enters the variable focus lens 22.

As another configuration, as shown in FIG. 13, one or a plurality of point light sources 110 are provided for the two-dimensional image display unit 11, and the light emitted from the point light sources 110 is emitted. A structure having an illumination optical system 121 that converts the light into parallel light and makes the light incident on each display element 21 of the two-dimensional image display unit 11 may be used.
Here, as shown in FIG. 13, one for the two-dimensional image display unit 11, or for each region for displaying the element image (the display element range of the two-dimensional image display unit 11 corresponding to the fixed focus lens 23). The illumination light optical system 121 may be provided, and parallel light may be incident on the display elements 21 arranged correspondingly.

<Fourth Embodiment>
Next, a fourth embodiment of the present invention will be described with reference to the drawings. FIG. 14 is a schematic block diagram illustrating a configuration example of the three-dimensional image display device according to the present embodiment. The fourth embodiment relates to the arrangement of the point light source 110, and the other configurations and operations are the same as those in any one of the first to third embodiments.
With respect to one display element 21 of the two-dimensional image display unit 11, a plurality of point light sources 110 (4 × 4 = 16 in a lattice arrangement of four rows in the x direction and four columns in the y direction in the figure) are provided. Is selected as a point light source 110 that emits light from among the plurality of point light sources 110 provided for each display element 21, and the selected point light source 110 is turned on, thereby displaying the display element. The light transmitted through 21 can be tilted.

Then, the light having the above tilt is transmitted through the variable focus lens 22, so that the position of the condensing point 111 on the x, y plane (two-dimensional plane) of the light tilt angle and the depth of image formation. It can be moved in the two-dimensional plane direction by a distance corresponding to the distance.
Then, the fixed focus lens 23 forms a three-dimensional reconstructed image using the point where the light emitted from the condensing point 111 is imaged as a pixel.
In this configuration, it is possible to finely adjust the pixel position (image formation position of light) in the x, y two-dimensional plane of the reproduced image 143 by selecting the point light source 110 on the back surface.

<Fifth Embodiment>
Next, a fifth embodiment of the present invention will be described with reference to the drawings. FIG. 15 is a schematic block diagram illustrating a configuration example of the three-dimensional image display apparatus according to the present embodiment. The fifth embodiment relates to a configuration for switching between displaying a three-dimensional image or displaying a two-dimensional image in a three-dimensional image display device. For other configurations and operations, the first embodiment is described. This is the same as the configuration and operation of any one of the fourth to fourth embodiments.
As shown in FIG. 15A, in the light traveling direction, the polarization direction of the light is changed to the first polarization direction (for example, p phase) and the second polarization direction (for example, in the next stage of the two-dimensional image display unit 11. For example, a polarization conversion element 151 that can be switched to (s phase) is provided. For example, the polarization conversion element 151 according to the present embodiment has the first polarization direction when no voltage is applied (FIG. 15A), and the second polarization direction when the voltage is applied (FIG. 15B). It becomes the polarization direction. Here, the display control unit 10 controls the application of voltage by performing selection control of whether the observer displays a three-dimensional image or a two-dimensional image with a changeover switch.

And as shown to Fig.15 (a), when the voltage is not applied with respect to the polarization conversion element 151, the polarization conversion element 151 converts the polarization direction into the 1st polarization direction of the incident light. When light is incident in the first polarization direction, the variable focus lens 22 has, for example, a focus adjustment function (a function of changing the focal length by a variable amount Δf) with respect to the first polarization direction. It has a structure that works. The fixed focus lens 23 also has a certain focal length with respect to the first polarization direction.
On the other hand, as shown in FIG. 15B, when a voltage is applied to the polarization conversion element 151, the polarization conversion element 151 has a polarization direction of light that is opposite in phase to the first polarization direction. The polarization direction of incident light is converted into the second polarization direction. When light having the second polarization direction is incident, the focal lengths of all the variable focus lenses 22 are constant regardless of the control. The fixed focus lens 23 is also made of a material that does not function as a lens function in the second polarization direction, that is, a glass substrate.
With the configuration described above, a three-dimensional image is displayed in the case of FIG. 15A on the three-dimensional image display device of the present embodiment by electrical control of the polarization conversion element 151, and in the case of FIG. 15B. Can display a two-dimensional image.

Similar to the configuration described above, FIG. 16 shows another configuration for switching and displaying a three-dimensional image and a two-dimensional image. The focal length of the variable focal lens 22 in the variable focal lens array 12 is controlled, and the position of the focal point of the variable focal lens 22 is changed from the fixed focal lens 23 to twice the focal length g of the fixed focal lens 23. Control. In this control as well, the display control unit 10 controls the focal length of the variable focus lens 22 by selecting whether the observer displays a three-dimensional image or a two-dimensional image with a switch.
At this time, the position of the pixel imaged by the fixed focus lens 23 is imaged at a magnification of 1 at a distance of 2 g from the fixed focus lens array 13. For example, the pixel of the condensing point 1a is displayed at the coordinate point 1a ′, the pixel of the condensing point 1b is displayed at the coordinate point 1b ′,..., And the pixel of the condensing point 2c is displayed at the coordinate point 2c ′.
As the number of pixels imaged at this magnification of 1 ×, the same number of pixels as the number of display elements 21 of the two-dimensional image display unit 11 is on the x, y two-dimensional plane at a distance of 2 g from the fixed focus lens array 13. To be played.
By controlling the pixels so that an image reproduced at this time is reproduced as a normal two-dimensional image, it is possible to switch between displaying a three-dimensional image and displaying a two-dimensional image.

Further, as shown in FIG. 17, the focal lengths of all the variable focal lenses 22 in the variable focal lens array 12 are controlled to be constant, and the positions of the condensing points 1a to 2c by the variable focal lens 22 are fixed focal points. The position is set at a distance A from the lens 23. At this time, the position of the image forming point reproduced via the fixed focus lens 23 is on a two-dimensional plane separated by a distance A from the fixed focus lens array 13. In this control as well, the display control unit 10 controls the focal length of the variable focus lens 22 by selecting whether the observer displays a three-dimensional image or a two-dimensional image with a switch.
At this time, it is possible to display a two-dimensional image in a two-dimensional plane by setting the distance A so that the distance between the condensing points 1a to 2c of each focus variable lens 22 is constant. At this time, the two-dimensional image display unit 11 displays so that a correct two-dimensional image is reproduced when the two-dimensional image is reproduced.

In the case of the configuration for switching the display of the three-dimensional image and the two-dimensional image described with reference to FIGS. 16 and 17, as shown in FIG. It is good also as a structure arrange | positioned on the two-dimensional plane which a pixel image-forms when displaying. When displaying a three-dimensional image, the diffusion modulation screen 181 is made transparent so that pixels can be displayed in the depth direction. On the other hand, when a two-dimensional image is displayed, the diffusion degree of the diffusion modulation screen 181 is raised to a diffusion state. In this control as well, the display control unit 10 controls the focal length of the variable focal length lens 22 and the diffusion modulation screen 181 by selecting whether the observer displays a three-dimensional image or a two-dimensional image with a switch. Control diffusivity.
In the present embodiment described above, when displaying the two-dimensional image, the display control unit 10 divides the area of the display element 21 of the two-dimensional image display unit 11 and displays the element image for each divided area. Without displaying, a two-dimensional image is displayed on the entire surface in the same manner as a normal two-dimensional display. Moreover, parallel light is incident on each display element 21 from a point light source (not shown).

  Further, a program for realizing the function of calculating the coordinate position of the display control unit 10 in FIG. 1 is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read into a computer system and executed. The coordinate position may be calculated by doing so. Here, the “computer system” includes an OS and hardware such as peripheral devices.

Further, the “computer system” includes a homepage providing environment (or display environment) if a WWW system is used.
The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Furthermore, the “computer-readable recording medium” dynamically holds a program for a short time like a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line. In this case, a volatile memory in a computer system serving as a server or a client in that case, and a program that holds a program for a certain period of time are also included. The program may be a program for realizing a part of the functions described above, and may be a program capable of realizing the functions described above in combination with a program already recorded in a computer system.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes design and the like within a scope not departing from the gist of the present invention.

As described above, each embodiment of the present invention does not require the use of special glasses for observing a 3D image as in the prior art, and is a display that displays a natural 3D image by a still image and a moving image. This is a three-dimensional image display device that can be used.
For example, each embodiment of the present invention can be used as a home display in the future 3D video broadcasting era and for applications requiring 3D video such as medical treatment, games, and education.

DESCRIPTION OF SYMBOLS 1a, 1b, 1c, 2a, 2b, 2c, 43, 111 ... Condensing point 10 ... Display control part 11 ... Two-dimensional image display part 12 ... Variable focus lens array 13 ... Fixed focus lens array 14, 61, 143 ... Reproduction | regeneration Image 21 ... Display element 22 ... Variable focus lens 23 ... Fixed focus lens 32, 33, 34 ... Pixel 110 ... Point light source 91 ... Micro display 92 ... Micro display drive circuit 93 ... External synchronization signal 100 ... Display block 120 ... Illumination optical system 151... Polarization conversion element 181... Diffusion modulation screen B1, B2, B3, B4, B5, B6, B7, B8, B9.

Claims (7)

An integral photography type three-dimensional image display device that displays a three-dimensional image by superimposing corresponding pixels in a plurality of element images that are two-dimensional planar images in a three-dimensional space;
A two-dimensional image display section in which a plurality of display elements are arranged and the display elements are divided into a plurality of divided regions for displaying the element image;
A variable-focus lens disposed on the optical axis of each display element in the two-dimensional image display unit;
A lens disposed at a position overlapping with each of the divided regions on the light emission side of the variable focus lens;
Corresponding to the coordinate position of the pixel of the three-dimensional image in the three-dimensional space, and controlling the focal length of the variable focus lens corresponding to the display element for each display element in the two-dimensional image display unit, A display control unit configured to condense light emitted from the display elements in the plurality of divided regions constituting one pixel in the three-dimensional image by the lens at the same position in the three-dimensional space. A characteristic three-dimensional image display device.   The three-dimensional display according to claim 1, wherein the display element in the two-dimensional image display unit is formed of a light-emitting element that is a point light source having a diameter smaller than a grid interval corresponding to a set resolution. Image display device. The two-dimensional image display unit
A light emitting section that can be regarded as a point light source having a diameter smaller than the grid interval corresponding to the set resolution;
2. The three-dimensional image display device according to claim 1, wherein the three-dimensional image display device is formed of a display element array which is a transmission type or a reflection type and in which display elements for modulating light from the light emitting section are arranged.   The divided region, the variable focus lens provided corresponding to the display element of the divided region, a lens arranged at a position overlapping the divided region in plan view, and a variable focus lens corresponding to the divided region The three-dimensional image display device according to any one of claims 1 to 3, wherein the display control unit that adjusts the image is configured as one display module.   A plurality of point light sources are provided for the variable focus lens, and the position of the pixel of the three-dimensional image is controlled on a two-dimensional plane parallel to the two-dimensional image display unit depending on which point light source is used. The three-dimensional image display device according to any one of claims 1 to 4.   The display control unit sets the focal lengths of all the variable focus lenses corresponding to the display elements of the two-dimensional image display unit to the same preset value, thereby determining the position of the condensing point by the variable focus lens. A two-dimensional display plane parallel to a two-dimensional image display unit at a predetermined distance from the lens is used, and an image displayed on the two-dimensional image display unit is displayed on the two-dimensional display plane. The three-dimensional image display apparatus according to any one of claims 1 to 5. A diffusion screen disposed at the position of the two-dimensional display plane and switching between a transparent state for transmitting light and a state for diffusing light;
7. When displaying a three-dimensional image, the diffusion screen is set in a transparent state that allows light to pass therethrough, and when displaying a two-dimensional image, the diffusion screen is set in a state in which light is diffused. The three-dimensional image display device described in 1.

Images