JP2007108274A - Three-dimensional display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To present only beautiful three-dimensional images to an observer, without making the observer observe a plurality of blurred two-dimensional images. <P>SOLUTION: The three-dimensional display device displays a three-dimensional display image, by displaying two-dimensional images on a plurality of display screens disposed in different depths, as viewed from an observer. The three-dimensional display device has a sight-limiting device that allows an observer to observe only from a narrow area around the observer. The sight-limiting device is a device, by which the directionality of light emitted from each of back lights disposed optically behind the corresponding display screens, as viewed optically from the observer is narrowed around the observer. Alternatively, the sight-limiting device is a device that intercepts light other than light in the direction of the observer. Alternatively, the sight limiting device is a device, by which light other than light in the direction of the observer is made to condense in the direction of the observer. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a three-dimensional display device, and more particularly to a DFD (Depth-Fused3-D) type three-dimensional display device.

The present inventors have proposed a DFD-type three-dimensional display device that can suppress contradiction among physiological factors of stereoscopic vision and can easily perform three-dimensional display without using stereoscopic glasses. (For example, refer to Patent Documents 1 and 2).
The proposed three-dimensional display device described above displays a two-dimensional image on a plurality of display surfaces, and changes the brightness or transparency of the two-dimensional image displayed on the plurality of display surfaces for each display surface. A three-dimensional stereoscopic image is displayed.

As prior art documents related to the invention of the present application, there are the following.
Japanese Patent No. 3022558 Japanese Patent No. 3460671

In the three-dimensional display method described above, a three-dimensional stereoscopic image is displayed by overlapping two-dimensional images displayed on a plurality of display surfaces arranged at different depth positions as viewed from the observer.
However, when the observer observes from other than the overlapping viewpoint, an image with poor image quality is observed in a state where a plurality of two-dimensional images are shifted, not as a three-dimensional stereoscopic image.
The present invention has been made to solve the above-described problems of the prior art, and an object of the present invention is to allow an observer to observe an image in which a plurality of two-dimensional images are shifted in a three-dimensional display device. Therefore, it is an object of the present invention to provide a technique capable of presenting only a beautiful three-dimensional stereoscopic image to an observer.
Another object of the present invention is to efficiently concentrate light emitted from each display surface or transmitted light transmitted through each display surface only in a narrow range centering on the observer in the three-dimensional display device. Thus, the power consumption for displaying an image on the self-luminous display device constituting each display surface, or the power consumption necessary for turning on the backlight for illuminating the transmissive display device constituting each display surface. The object is to provide a technique that can be significantly reduced.
The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

Of the inventions disclosed in this application, the outline of typical ones will be briefly described as follows.
In order to solve the above-described problems, the present invention provides a three-dimensional display device that displays a three-dimensional stereoscopic image by displaying two-dimensional images on a plurality of display surfaces arranged at different depth positions as viewed from an observer. And a viewing zone limiting device capable of observing only from a narrow range centering on the direction of the observer.
In the present invention, the three-dimensional display device displays on each display surface a two-dimensional image obtained by projecting a display target object from the viewing direction of the observer on each display surface, and displays the two-dimensional image. A three-dimensional stereoscopic image is displayed by independently changing the luminance or transmittance of the two-dimensional image for each display surface.

Further, in the present invention, the viewing area limiting device is provided between the frontmost display surface viewed from the observer and the observer, or optically viewed from the observer. Arranged forward.
In the present invention, when the display surface is a transmissive type that transmits light from the back surface, the viewing area limiting device is behind the last display surface as viewed from the observer, or from the observer. Optically disposed behind each display surface.
Further, in the present invention, the viewing zone limiting device is a device that narrows the directivity of the irradiation light of the backlight arranged behind the display surface, centering on the direction of the observer.
In the present invention, the viewing area limiting device is a device that blocks light other than the direction of the observer.
In the present invention, the viewing area limiting device is a device that condenses light other than the direction of the observer in the direction of the observer.

The effects obtained by the representative ones of the inventions disclosed in the present application will be briefly described as follows.
(1) According to the three-dimensional display device of the present invention, since the plurality of two-dimensional images can be observed only from the viewpoint direction where the two-dimensional images overlap, the observer can observe an image in which the plurality of two-dimensional images are shifted. In addition, only a beautiful three-dimensional image can be presented to the observer.
(2) According to the three-dimensional display device of the present invention, the emitted light on each display surface or the transmitted light transmitted through each display surface can be efficiently concentrated only in a narrow range centered on the observer. Therefore, the power consumption for displaying an image on the self-luminous display device constituting each display surface, or the power consumption necessary for turning on the backlight for illuminating the transmissive display device constituting each display surface. It becomes possible to reduce significantly.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In all the drawings for explaining the embodiments, parts having the same functions are given the same reference numerals, and repeated explanation thereof is omitted.
[Example of DFD type 3D display device]
FIG. 8 is a diagram for explaining an example of a DFD type three-dimensional display device.
The three-dimensional display device shown in FIG. 8 sets a plurality of surfaces, for example, display surfaces (11, 12) (the display surface 11 is closer to the observer 100 than the display surface 12) on the front surface of the observer 100. In order to display a plurality of two-dimensional images on the display surfaces (11, 12), an optical system 13 is constructed using a two-dimensional display device and various optical elements.
Examples of the two-dimensional display device include a CRT, a liquid crystal display panel, an LED display panel, a plasma display panel, an EL display panel, an FED display panel, a DMD, a projection display panel, and a line drawing display such as an oscilloscope. As the optical element, for example, a lens, a total reflection mirror, a partial reflection mirror, a curved mirror, a prism, a polarization element, a wave plate, or the like is used.
Note that FIG. 8 has the same configuration as that described in the above-mentioned Patent Document 1, and refer to the above-mentioned Patent Document 1 for the method of setting the display surface.
In the three-dimensional display device shown in FIG. 8, as shown in FIG. 9, the three-dimensional object 16 to be presented to the observer 100 is transferred from the line of sight of both eyes of the observer 100 to the display surface (11, 12). A projected image (hereinafter referred to as a “2D image”) (14, 15) is generated.
As a method for generating this 2D image, for example, a method using a two-dimensional image obtained by photographing a three-dimensional object 16 with a camera from the line-of-sight direction, a method of combining from a plurality of two-dimensional images taken from different directions, or There are various methods such as a computer graphic synthesis technique and a method using modeling.

As shown in FIG. 8, the 2D image (14, 15) overlaps both the display surface 11 and the display surface 12 as seen from one point on the line connecting the right eye and the left eye of the viewer 100, respectively. To display. This can be achieved, for example, by controlling the arrangement of the center position and the gravity center position of each 2D image (14, 15) and the enlargement / reduction of each image.
On the apparatus having such a configuration, the luminance of each of the 2D images (14, 15) is changed in accordance with the depth position of the three-dimensional object 16 while keeping the overall luminance viewed from the observer 100 constant. Thus, a three-dimensional stereoscopic image of the three-dimensional object 16 is displayed.
An example of how to change the brightness of each 2D image (14, 15) will be described. Here, since it is a black and white drawing, for the sake of easy understanding, in the following drawings, the higher luminance is shown darker.
For example, when the three-dimensional object 16 is on the display surface 11, as shown in FIG. 10, the luminance of the 2D image 14 above is made equal to the luminance of the three-dimensional object 16 and 2D on the display surface 12 is displayed. The brightness of the converted image 15 is zero.
Next, for example, when the three-dimensional object 16 is slightly away from the viewer 100 and is slightly closer to the display surface 12 than the display surface 11, the brightness of the 2D image 14 is increased as shown in FIG. Slightly lower the brightness of the 2D image 15 slightly.

Next, for example, when the three-dimensional object 16 is further away from the observer 100 and is further away from the display surface 11 toward the display surface 12, the luminance of the 2D image 14 is increased as shown in FIG. Further down, the brightness of the 2D image 15 is further increased.
Further, for example, when the three-dimensional object 16 is on the display surface 12, as shown in FIG. 13, the luminance of the 2D image 15 above is made equal to the luminance of the three-dimensional object 16, and the The brightness of the 2D image 14 is zero.
By displaying in this way, even if the 2D image (14, 15) is displayed due to the physiological or psychological factors or illusions of the observer (person) 100, it is as if the observer 100 is present. It feels as if the three-dimensional object 16 is located in the middle of the display surfaces (11, 12).
For example, when a 2D image (14, 15) having substantially the same luminance is displayed on the display surface (11, 12), the three-dimensional object 16 appears near the middle of the depth position of the display surface (11, 12). I can feel it. In this case, the three-dimensional object 16 is perceived by the observer 100 with a stereoscopic effect.

In the above description, for example, the method of expressing the depth position of the entire three-dimensional object using, for example, a two-dimensional image displayed on the display surface (11, 12) has been mainly described. It is obvious that the 3D display device can be used as a method of expressing the depth of the 3D object itself, for example.
An important point in expressing the depth of the three-dimensional object itself is that the luminance of each part of the 2D image (14, 15) is viewed from the observer 100 on the apparatus having the configuration shown in FIG. It is to change corresponding to the depth position of each part of the three-dimensional object 16 while keeping the overall luminance constant.
In the above description, the description has been given of the case where only two surfaces are mainly described among the surfaces on which the two-dimensional image is arranged, and the object to be presented to the observer is between the two surfaces. It is obvious that a three-dimensional stereoscopic image can be displayed by a similar method even when the number of surfaces on which images are arranged is larger than this or when the position of an object to be presented is different.
For example, there are three surfaces, a first three-dimensional object between the surface close to the observer 100 and the intermediate surface, and a second 3 between the intermediate surface and the surface far from the observer 100. When a three-dimensional object exists, a 2D image of the first three-dimensional object is displayed on a surface close to the observer 100 and an intermediate surface, and on the intermediate surface and a surface far from the observer 100. By displaying the 2D image of the second 3D object, it is possible to display 3D images of the first and second 3D objects.

Furthermore, regarding the case where the 2D image is moved three-dimensionally, the movement of the observer in the horizontal and vertical directions can be achieved by moving image reproduction on the display surface as in the case of a normal two-dimensional display device. Regarding the movement in the depth direction, the luminance of each of the 2D images (14, 15) is changed with time in the depth position of the three-dimensional stereoscopic image while keeping the overall luminance seen from the observer 100 constant. It is clear that a moving image of a three-dimensional image can be expressed by changing it correspondingly.
For example, a case where a three-dimensional stereoscopic image moves from the display surface 11 to the display surface 12 in time will be described.
When the three-dimensional stereoscopic image is on the display surface 11, the luminance of the 2D image 14 on the display surface 11 is made equal to the luminance of the three-dimensional stereoscopic image, as shown in FIG. The brightness of the converted image 15 is zero.
Next, for example, when the three-dimensional stereoscopic image gradually moves away from the viewer 100 in time and slightly approaches in time from the display surface 11 toward the display surface 12, as shown in FIG. Corresponding to the movement of the depth position of the three-dimensional stereoscopic image, the luminance of the 2D image 14 is slightly lowered in time, and the luminance of the 2D image 15 is slightly increased in time.

Next, for example, when the three-dimensional stereoscopic image is further distant from the observer 100 in time and moved to the position closer to the display surface 12 than the display surface 11, as shown in FIG. Corresponding to the movement of the depth position of the three-dimensional stereoscopic image, the luminance of the 2D image 14 is further lowered in time, and the luminance of the 2D image 15 is further raised in time.
Further, for example, when the three-dimensional stereoscopic image has moved to the display surface 12 over time, as shown in FIG. 13, the 2D image above this corresponding to the movement of the depth position of the three-dimensional stereoscopic image. The luminance of 15 is changed over time until it becomes equal to the luminance of the three-dimensional stereoscopic image, and is changed until the luminance of the 2D image 14 on the display surface 11 becomes zero.
By displaying in this way, even if a 2D image (14, 15) is displayed due to a human physiological or psychological factor or illusion, the viewer 100 is as if the display surface (11, 12), it is felt that the three-dimensional stereoscopic image moves from the display surface 11 to the display surface 12 in the depth direction.

In the above description, the case where the three-dimensional stereoscopic image moves from the display surface 11 to the display surface 12 has been described. However, this moves from the halfway position between the display surfaces (11, 12) to the display surface 12. Or when moving from the display surface 11 to a halfway depth position between the display surfaces (11, 12) or from a halfway depth position between the display surfaces (11, 12). It is clear that the same can be done even when moving to another depth position in the middle.
In the above description, a description is given of a case where only two surfaces are mainly described among surfaces on which a 2D image is arranged, and a three-dimensional stereoscopic image presented to the observer 100 moves between the two surfaces. However, even if the number of planes on which a two-dimensional image is arranged is larger than this, or even when a three-dimensional object to be presented moves across multiple planes, a three-dimensional stereoscopic image is displayed using the same method. Obviously, similar effects can be expected.
In the above description, the case where one three-dimensional stereoscopic image moves in two planes on which two-dimensional images are arranged has been described. However, when a plurality of three-dimensional objects move, that is, displayed. When the two-dimensional image includes a plurality of object images having different movement directions, the luminance of the object image displayed on each display surface changes for each object image according to the movement direction and movement speed of the object. Obviously, you can do that.

[Other examples of DFD type 3D display devices]
FIG. 14 is a diagram for explaining another example of the DFD type three-dimensional display device as a premise of the present invention.
The three-dimensional display device shown in FIG. 14 has a plurality of transmissive display devices such as transmissive display devices (21, 22) (the transmissive display device 21 is more observable than the transmissive display device 22 in front of the observer 100. The optical system 13 is constructed using various optical elements and a light source 23. That is, in this embodiment, the transmissive display devices (21, 22) are used in place of the display surfaces (11, 12) in FIG.
Examples of the transmissive display devices (21, 22) include twisted nematic liquid crystal display panels, in-plane liquid crystal display panels, homogeneous liquid crystal display panels, ferroelectric liquid crystal display panels, guest-host liquid crystal display panels, A polymer dispersed liquid crystal display panel, a holographic polymer dispersed liquid crystal display panel, or a combination thereof is used. In addition, as the optical element, for example, a lens, a total reflection mirror, a partial reflection mirror, a curved mirror, a prism, a polarization element, a wave plate, or the like is used.
FIG. 14 shows a case where the backlight (light source) 23 is arranged at the rearmost position when viewed from the observer 100, and FIG. 14 shows the same configuration as that described in Patent Document 2 described above. belongs to.

Also in the three-dimensional display device shown in FIG. 14, as shown in FIG. 9 described above, the three-dimensional object 16 desired to be presented to the observer 100 is viewed from the observer 100 to the transmissive display device (21, 22). A projected 2D image (14, 15) is generated.
As shown in FIG. 14, the 2D image (14, 15) is applied to both the transmissive display device 21 and the transmissive display device 22 from one point on the line connecting the right eye and the left eye of the observer 100. Displayed as a 2D image (14, 15) so as to overlap.
This can be achieved, for example, by controlling the arrangement of the center position and the center of gravity position of each 2D image (14, 15) and the enlargement / reduction ratio of each image.
On the apparatus having the above-described configuration, an image viewed by the observer 100 is generated by light emitted from the light source 23, transmitted through the 2D image 15, and further transmitted through the 2D image 14.
In the three-dimensional display device shown in FIG. 14, the distribution of the transmittance of each of the 2D images (14, 15) is kept constant on the device having the above-described configuration while keeping the overall luminance viewed from the observer 100 constant. The three-dimensional stereoscopic image of the three-dimensional object existing between the transmissive display device 21 and the transmissive display device 22 is displayed in accordance with the depth position of the three-dimensional object 16.

An example of how to change the transmittance of each of the 2D images (14, 15) will be described.
For example, when the three-dimensional object 16 is on the transmissive display device 21, the transmittance on the transmissive display device 21 is set so that the luminance of the 2D image 14 is equal to the luminance of the three-dimensional object 16. The transmittance of the portion of the 2D image 15 on the transmissive display device 22 is, for example, the maximum value of the transmissive display device 22.
Next, for example, when the three-dimensional object 16 is slightly away from the observer 100 and is slightly closer to the transmissive display device 22 side than the transmissive display device 21, the 2D conversion on the transmissive display device 21 is performed. The transmittance of the portion of the image 14 is slightly increased, and the transmittance of the portion of the 2D image 15 on the transmissive display device 22 is slightly decreased.
Next, for example, when the three-dimensional object 16 is further away from the viewer 100 and is located closer to the transmissive display device 22 than the transmissive display device 21, the 2D display on the transmissive display device 21 is performed. The transmittance of the portion of the image 14 is further increased, and the transmittance of the portion of the 2D image 15 on the transmissive display device 22 is further decreased.
Further, for example, when the three-dimensional object 16 is on the transmissive display device 22, the transmittance on the transmissive display device 22 is set so that the luminance of the 2D image 15 is equal to the luminance of the three-dimensional object 16. For example, the transparency of the portion of the 2D image 14 on the transmissive display device 21 is set to the maximum value of the transmissive display device 21.

By displaying in this way, even if the 2D image (14, 15) is displayed due to the physiological or psychological factors or illusions of the observer (person) 100, it is as if the observer 100 is present. It feels as if the three-dimensional object 16 is located in the middle of the transmissive display device (21, 22).
That is, for example, when a 2D image (14, 15) having substantially the same luminance is displayed on the transmissive display device (21, 22), 3 is displayed near the middle of the depth position of the transmissive display device (21, 22). It feels like there is a dimensional object 16. In this case, the three-dimensional object 16 is perceived by the observer 100 with a stereoscopic effect.
In the above description, for example, the method of expressing the depth position of the entire three-dimensional object using, for example, a two-dimensional image displayed on the transmissive display device (21, 22) has been mainly described. It is obvious that the three-dimensional display device shown in FIG. 14 can also be used as a method of expressing the depth of the three-dimensional object itself, for example, by a method similar to the method described in the three-dimensional display device shown in FIG.
In the three-dimensional display device shown in FIG. 14 as well, when the 2D image is moved three-dimensionally by the same method as that described in the three-dimensional display device shown in FIG. The movement in the vertical direction is possible by moving image reproduction in the transmissive display device as in the case of a normal two-dimensional display device, and the movement in the depth direction is transmitted through a plurality of transmissive display devices. It is obvious that a moving image of a three-dimensional stereoscopic image can be expressed by temporally changing the degree.

[Modification of 3D Display Device Shown in FIG. 14]
FIG. 15 is a diagram for explaining a modification of the three-dimensional display device shown in FIG.
In the three-dimensional display device shown in FIG. 15, the transmissive display device 21, the scattering plate 33, and the transmissive display device 22 are disposed between the polarizing plate 30 and the polarizing plate 36.
The transmissive display device 21 includes a liquid crystal display panel 32 that functions as a polarization variable device and a color filter 31. Similarly, the transmissive display device 22 includes a liquid crystal display panel 35 that functions as a polarization variable device, and a color filter. And a filter 34.
A light source (backlight) 23 is disposed behind the polarizing plate 36 (on the side opposite to the transmissive display device 22 of the polarizing plate 36).
Here, the liquid crystal display panels (32, 35) are polarizing plates from twisted nematic liquid crystal display panels, in-plane liquid crystal display panels, homogeneous liquid crystal display panels, ferroelectric liquid crystal display panels, antiferroelectric liquid crystal display panels, and the like. It consists of a device that has been removed.
Since the liquid crystal display panel (32, 35) can change the direction of polarization for each pixel, the intensity of the emitted light can be changed according to the polarization direction of the emitted light and the polarization direction of the polarizing plate on the exit side. As described above, the light transmittance can be changed.
Therefore, the transmittance can be changed independently for each of the liquid crystal display panel 32 and the liquid crystal display panel 35 by controlling the polarization direction of the light passing therethrough for each pixel unit of the liquid crystal display panel (32, 35). .

Even in the three-dimensional display device shown in FIG. 15, the three-dimensional display device 21 or 22 is placed on the transmissive display device (21, 22) or an arbitrary position between the transmissive display device 21 and the transmissive display device 22 by the above-described method. A stereoscopic image can be displayed.
Moreover, in the three-dimensional display device shown in FIG. 15, since the liquid crystal display panel (32, 35) is sandwiched between two polarizing plates (30, 36), a polarizing plate is provided on both sides as a transmissive display device. Compared with the case where the provided liquid crystal display panel is used, the number of polarizing plates inserted in the optical path of the irradiation light from the light source 23 can be reduced, and the display can be prevented from becoming dark.
In the three-dimensional display device shown in FIG. 15, a color filter (31) composed of three colors of red (R), green (G), and blue (B) is provided for each pixel of each liquid crystal display panel (32, 35). , 34) are arranged, so that a three-dimensional stereoscopic image of a color image can be displayed.
However, in the three-dimensional display device shown in FIG. 15, the polarization direction of each liquid crystal display panel (32, 35) is taken into consideration that the polarization direction changes while passing through the liquid crystal display panel 32 and the liquid crystal display panel 35. It is necessary to control the direction.
In the three-dimensional display device shown in FIG. 15, each transmissive display device (21, 22) includes a liquid crystal display panel (32, 35) functioning as a polarization variable device and a color filter (31, 34). . Therefore, moire may occur due to differences in the arrangement direction, arrangement pitch, and the like of the red (R), green (G), and blue (B) filters in the color filter 31 and the color filter 34.
For this reason, in the three-dimensional display device shown in FIG. 15, the scattering plate 33 is disposed between the color filter 31 and the color filter 34 to prevent the above-described moire from occurring.

[Example 1]
FIG. 1 is a cross-sectional view of a main part showing a schematic configuration of a three-dimensional display device according to Embodiment 1 of the present invention.
The three-dimensional display device according to the present embodiment is basically configured by stacking a plurality of transmissive display devices constituting a display surface. As shown in FIG. 1, the transmissive display device at the forefront (the forefront as viewed from the viewer) of the transmissive display devices (111, 112) arranged at different depth positions as viewed from the viewer. A viewing area limiting device 121 that limits light from other than near the front of the transmissive display device (111, 112) is disposed between the viewer 111 and the viewer 101.
As a result, a three-dimensional image of the three-dimensional display device using the transmissive display device (111, 112) can be observed from the direction of the observer 101, but can be observed from the direction of the observer (102, 103). become unable.
Conventionally, in a three-dimensional display device in which a plurality of transmissive display devices are stacked, when the image is observed from other than near the front where the images overlap, gaps can be seen between the images of the display devices, or the images overlap. As a result, an image different from the original three-dimensional image is observed by the observer.
In the present embodiment, by limiting the viewing direction other than the original three-dimensional image, it is possible to show only a beautiful original three-dimensional image to the observer.
In addition, although FIG. 1 demonstrates the case where an image overlaps from the front of a transmissive display apparatus (111,112), when each image is overlap | superposed from other than the front, it is except for the overlapping gaze direction. By limiting, it is possible to observe only the original three-dimensional image.

FIG. 2 is a cross-sectional view of a principal part showing a schematic configuration of a modification of the three-dimensional display device according to Embodiment 1 of the present invention. The three-dimensional display device shown in FIG. 2 has a basic configuration in which a plurality of non-transparent display devices (211 and 212) are superposed, and in FIG. 2, the light is reflected and transmitted. A plurality of non-transparent display devices (211, 212) are optically superimposed using half mirrors (231, 232). The non-transparent display devices (211 and 212) constitute a display surface.
The viewing area limiting devices (221, 222) are respectively arranged in front of the non-transparent display devices (211 and 212) (frontward when viewed optically from the observer), and the viewing direction is limited. Yes. Thereby, the same effect can be realized in the non-transmissive display device as in the transmissive display device shown in FIG.
The viewing area limiting device of this embodiment can be configured with a louver 511 that blocks a line of sight from other directions by setting a wall in a direction perpendicular to the display device, like the viewing area limiting device 521 shown in FIG.
It is also possible to condense the observation range by directing light toward the observer with an optical system such as a lens or a prism. In other words, the viewing area limiting device is not limited to simply blocking and restricting areas other than the desired viewing area, but also improves the light utilization efficiency by collecting light in other viewing area directions in the desired direction. Is possible.
For example, when the non-transmissive display device (211 and 212) is a self-luminous display device, the power consumption of the self-luminous display device is obtained by condensing all of the emitted light in an angular direction only near the center. Can be significantly reduced.
Furthermore, as shown in FIG. 4, for example, a viewing area limiting device 621 using a microlens 611 corresponding to each pixel is arranged on the front surface of the display device 631, and the light emitted from the display device 631 is directed to the observer. It can also be realized by condensing light.

[Example 2]
FIG. 5 is a cross-sectional view of an essential part showing a schematic configuration of a three-dimensional display device according to Embodiment 2 of the present invention.
The three-dimensional display device of the present embodiment is also basically based on a configuration in which a plurality of transmissive display devices are stacked. Then, as shown in FIG. 5, the rear side of the plurality of transmissive display devices (311, 312) arranged at different depth positions as viewed from the viewer (the last surface as viewed from the viewer) is viewed behind. A region limiting device 321 is arranged.
Since the transmissive display device performs display by transmitting light from the back surface, the range of light coming from the back surface is limited by the viewing area limiting device 321, so that a plurality of transmissive display devices (311, 312) are displayed. ) Can be observed only from the overlapping direction.
As a result, a three-dimensional image of the three-dimensional display device using the transmission type display devices (311 and 312) can be observed from the direction of the observer 301, but can be observed from the direction of the observer (302, 303). become unable.
FIG. 6 is a cross-sectional view of a main part showing a schematic configuration of a modified example of the three-dimensional display device according to Embodiment 2 of the present invention. The three-dimensional display device shown in FIG. 6 is obtained by optically superimposing transmissive display devices (411, 412) using half mirrors (431, 432).
In the three-dimensional display device shown in FIG. 6, the viewing area limiting devices (421, 422) are arranged on the rear surfaces (back surfaces as viewed optically from the observer) of the transmissive display devices (411, 412). By limiting the range of light from the rear surface, it is possible to limit the range that can be observed in the same manner as the three-dimensional display device shown in FIG.

The light from the back surface may be naturally incident light, but there is also a method of direct illumination such as backlights (331, 441, 442).
The viewing area limiting device disposed on the rear surface of the transmissive display device is not limited to simply blocking and restricting areas other than the desired viewing area, but also collects light in other viewing area directions in a desired direction. It is also possible to increase the use efficiency.
For example, it is possible to reduce the power consumption of the backlight to about 1/5 by condensing all the light (100%) emitted from the backlight in an angular direction of only 20% near the center.
In a DFD type three-dimensional display device, since a plurality of transmissive display devices are overlapped, the display luminance is low, so it is known that a high-luminance backlight is necessary, and the luminance of the backlight is reduced. Alternatively, reduction in power consumption is advantageous in a DFD three-dimensional display device.
The viewing area limiting device of this embodiment can be configured by an optical system such as a lens, a microlens, and a prism. For example, as shown in FIG. 7, light emitted from a backlight 741 in a wide range is condensed in the direction of the observer by an optical system such as a microlens or a lens, and the light is incident on a transmissive display device 731. Can be realized.
As mentioned above, the invention made by the present inventor has been specifically described based on the above embodiments. However, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. Of course.

It is principal part sectional drawing which shows schematic structure of the three-dimensional display apparatus of Example 1 of this invention. It is principal part sectional drawing which shows schematic structure of the modification of the three-dimensional display apparatus of Example 1 of this invention. It is principal part sectional drawing which shows schematic structure of an example of the visual field limitation apparatus of Example 1 of this invention. It is principal part sectional drawing which shows schematic structure of the other example of the visual field limitation apparatus of Example 1 of this invention. It is principal part sectional drawing which shows schematic structure of the three-dimensional display apparatus of Example 2 of this invention. It is principal part sectional drawing which shows schematic structure of the modification of the three-dimensional display apparatus of Example 2 of this invention. It is principal part sectional drawing which shows schematic structure of an example of the visual field limitation apparatus of Example 2 of this invention. It is a figure which shows schematic structure of the three-dimensional display apparatus used as the basis of this invention. It is a figure for demonstrating the production | generation method of the 2D-ized image displayed on each display surface in the three-dimensional display apparatus used as the foundation of this invention. It is a figure for demonstrating the display principle of the three-dimensional display apparatus used as the basis of this invention. It is a figure for demonstrating the display principle of the three-dimensional display apparatus used as the basis of this invention. It is a figure for demonstrating the display principle of the three-dimensional display apparatus used as the basis of this invention. It is a figure for demonstrating the display principle of the three-dimensional display apparatus used as the basis of this invention. It is a figure for demonstrating the other example of the DFD type three-dimensional display apparatus used as the premise of this invention. It is a figure for demonstrating the modification of the three-dimensional display apparatus shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11,12 Display surface 13 Optical system 14,15 2D-ized image 16 Three-dimensional object 21,22,111,112,311,312,311,412,631,731 Transmission type display device 23,331,441,442,741 Backlight 32, 35 Liquid crystal display panel 31, 34 Color filter 30, 36 Polarizing plate 33 Scattering plate 100, 101, 102, 103, 201, 202, 203, 301, 302, 303, 401, 402, 403, 501, 502 , 503, 601, 602, 603, 701, 702, 703 Viewer 121, 221, 222, 321, 421, 422, 521, 621, 721 Viewing area limiting device 231, 232, 431, 432 Half mirror 211, 212 Non Transparent display device 511 Louver 611,711 Micro lens

Claims (9)

In a three-dimensional display device that displays a three-dimensional stereoscopic image by displaying two-dimensional images on a plurality of display surfaces arranged at different depth positions as viewed from the observer,
A three-dimensional display device comprising a viewing zone limiting device that allows observation from only a narrow range centered on an observer's direction.   The three-dimensional display device displays, on each display surface, a two-dimensional image obtained by projecting a display target object on each display surface from the viewing direction of the observer, and the brightness of the displayed two-dimensional image or The three-dimensional display device according to claim 1, wherein a three-dimensional stereoscopic image is displayed by changing the transmittance independently for each display surface.   3. The three-dimensional display device according to claim 1, wherein the viewing area limiting device is disposed between a frontmost display surface viewed from the observer and the observer.   The three-dimensional display device according to claim 1, wherein the viewing area limiting device is disposed in front of each display surface as viewed optically from the observer.   The display area limiting device is arranged behind the last display surface when viewed from the observer when the display surface is a transmissive type that transmits light from the back surface. The three-dimensional display device according to claim 2.   The display area limiting device is disposed behind the display surfaces when viewed optically from the observer when the display surface is a transmissive type that transmits light from the back surface. The three-dimensional display device according to claim 1 or 2.   6. The device according to claim 5, wherein the viewing area limiting device is a device that narrows the directivity of the irradiation light of a backlight disposed behind the display surface with respect to the direction of the observer. The three-dimensional display device according to 6.   The three-dimensional display device according to any one of claims 1 to 7, wherein the viewing area limiting device is a device that blocks light other than a direction of the observer. 8. The three-dimensional image according to claim 1, wherein the viewing area limiting device is a device that collects light in a direction other than the direction of the observer in the direction of the observer. Display device.

Images