JP3528392B2 - Pseudo three-dimensional image display device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for stereoscopically displaying an image by utilizing the binocular parallax of an observer, and more particularly to a pseudo stereoscopic image display device which forms the binocular parallax with a prism.

[0002]

2. Description of the Related Art Conventionally, various methods for obtaining a stereoscopic effect by utilizing binocular parallax have been considered. Among various methods, it is known that a projection type three-dimensional image method using a directional screen can obtain a large pseudo three-dimensional image.
Various types of projection three-dimensional image systems have been considered depending on the type of screen, and there are various documents. For example, “3D Imaging Engineering” written by Takataka Ogoshi, published by Asakura Shoten 89
Some examples are introduced from page to page 97.

FIG. 2, which is a citation from this reference, illustrates the principle of obtaining a stereoscopic effect by utilizing binocular parallax. Photographs of the object taken from two different directions are placed at the positions of Photo 1 and Photo 2, and the images are viewed with the left and right eyes, respectively. As a result, the left and right eyes simultaneously view different images of the same object viewed from different directions, and a stereoscopic effect is obtained. According to this principle, the projection-type three-dimensional image system allows a viewer to view a pseudo-stereoscopic image on a large screen from any direction.

FIG. 3 shows one such method. Vertical m rows, horizontal n
Consider a case in which an m × n image is projected on the entire line. First, m × n cameras are arranged, and reversal photographs of the same object are taken. The reversal photograph is projected on a directional screen by m × n projectors arranged at the same intervals as the camera. As the directional screen, as shown in FIG. 3B, a directional screen provided with a diffuse reflection surface on the back focal plane of the fly's eye lens is used. As shown in FIG. 3C, this directional screen has a property of returning the reflected light in the incident direction of the incident light. Therefore, when an image emitted from one projector is used for the left eye, this image is Only incident on the left eye,
It is possible to make the image emitted from the projector next to the projector for the right eye and enter only the right eye of the observer. As a result, the observer obtains a stereoscopic effect due to the binocular parallax.

[0005]

The above-mentioned conventional technique has a problem that if the observer's viewpoint moving range (also referred to as a visual range) becomes wider, the number of m × n projectors required increases accordingly. . For example, when the required viewpoint movement range is 50 cm in width, 20 cm in height, and the camera interval is 5 cm, the number of projectors required is 10 × 4 = 40. Further, since the back surface of the lens plate must be a diffusion surface, the reflection efficiency is lower than that in the case where the back surface is a perfect reflection surface, and the obtained image is dark.

Therefore, an object of the present invention is to provide a stereoscopic display system in which the number of projectors is reduced to such an extent that the observer's viewpoint range is not narrowed so much and a bright image can be obtained.

[0007]

[Means for Solving the Problems] Since two human eyes are lined up horizontally, it is only necessary to obtain images for the left and right eyes in the horizontal direction. The above problems can be solved by using a directional screen having a property of a condensing reflecting mirror by providing a curvature in the direction. Furthermore, by slightly shifting the curvature center of the curvature in the vertical direction depending on the horizontal position, it is possible to expand the vertical viewing area of the observer.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

[First Embodiment] A first embodiment of the present invention will be described. FIG. 1 is an explanatory view showing an embodiment of a pseudo stereoscopic display system according to the present invention.

The reason why an observer can obtain a stereoscopic effect by seeing a three-dimensional object is that the left and right eyes simultaneously view different images of the same object viewed from different directions of the left and right eyes. Because I have a feeling. This is what is called binocular parallax in today's visual psychology. Pseudo-stereoscopic method is a picture of an object taken from two different directions as if it were viewed by the left eye and the right eye, and the images that would be seen when viewed by the left eye (hereinafter, Two-dimensional by viewing the left eye image with the left eye and the right eye image with the right eye (hereinafter referred to as the right eye image). This is a method to perceive the image (photograph) of 3D as a pseudo three-dimensional image.

In FIG. 1, 11 is a projector for projecting a left-eye image, and 12 is a projector for projecting a right-eye image.
Each of the projectors 11 and 12 is mounted on a stage 14 that allows fine adjustment of fine movements such as up / down, left / right, front / back, rotation, and tilt.
However, this configuration is only an example, and any image capable of projecting an image for producing a stereoscopic image on the directional screen 13 may be used.For example, when a moving image is desired, a transmissive liquid crystal panel is used, or It can be something like a general movie projector. In addition, the stage 14 also has an observer 15
The mechanism is not limited to this as long as it is a mechanism that adjusts the right eye image to the right eye of the observer 15 properly for the left eye. On the surface of the directional screen 13, a reflective film such as an Al 2 film is vapor-deposited so as to reflect light.

FIG. 4A shows a cross section of the directional screen 13 in the x direction. Since the two adjacent surfaces intersect each other at a right angle, the light incident on the screen 13 is reflected in the same direction as the incident direction within the xz plane. This principle is also applied to corner cubes. Therefore, each image (light) projected from each projector 11 and 12 is reflected by the screen 13 and then returned in the direction of each projector in the xz plane.

FIG. 4B shows a cross section of the directional screen 13 in the y direction. The cross section of the directional screen 13 in the y direction is a cross section of a reflecting mirror having a curvature (here, a spherical reflecting mirror), and the center of curvature and the radius of curvature in the y direction cross section at any position are constant. . Therefore, for each image (light) projected from each projector 11, 12, the screen 13 serves as a spherical reflecting mirror in the yz plane. The spherical reflecting mirror reflects the light incident non-parallel to the optical axis 41 symmetrically with respect to the optical axis, so that the optical axis of the y-direction sectional reflecting mirror of the directional screen 13 should be slightly upward. Install 13. As a result, as shown in FIG. 1, each image (light) projected from each of the projectors 11 and 12 is reflected by the screen 13 and then passes through a path above each incident light in the yz plane. Head to the observer.

Therefore, as shown in FIG. 5, the left-eye image enters only the left eye of the observer 15 and the right-eye image enters only the right eye of the observer 15. Reflected in 2
You can feel a three-dimensional image as a three-dimensional image with depth. In FIG. 5, the observer 15 viewed the projected image above the projectors 11 and 12, but the position of the observer 15 can be changed by changing the direction of the optical axis of the y-direction cross-section reflecting mirror of the directional screen 13. it can.

Further, by placing the semi-transparent mirror 61 in the optical path as shown in FIG. 6, the optimum position for observing the projected image can be removed from the lines of the projectors 11 and 12 and the directional screen 13, and the observer 15 It can be made easier to see.

In the above description, two projectors 11 and 12 are used, but the number of projectors is not limited to two. M cameras (m is an integer of 3 or more) are arranged side by side, and the same object is photographed with a reversal film to make a slide.
The slides are projected by the m projectors 71 as shown in FIG. 7 in the same order as when they were shot. m
By considering any two adjacent projectors of the projectors 71 of the two sets, the image from the projector on the left side of the pair is taken as the left eye image, and the image from the projector on the right side is taken as the right eye image. The observer 15 can perceive the two-dimensional image reflected on the directional screen 13 as a three-dimensional image with depth. Therefore, even if the observer 15 moves in the lateral (x) direction, it is possible to successively insert new images from a pair of projectors into each eye.
It is possible to widen the lateral viewpoint movement range of 15. It is of course possible to put a semi-transparent mirror in the optical path and take out the optimum observation position from the line of the projector and the directional screen 13.

[Embodiment 2] FIG. 8 is a schematic view of another embodiment of the pseudo stereoscopic display system according to the present invention. The same components as those in FIG. 1 are designated by the same reference numerals as those in FIG. 1 and their detailed description is omitted.

In FIG. 8, a reflective film, for example, an Al film is vapor-deposited on the surface of the directional screen 81 so as to reflect light. The structure of the directional screen 81 will be described below.

As shown in FIG. 9, the directional screen 13 used in Example 1 is finely divided into a plurality of pieces in a direction parallel to the line of intersection where two adjacent surfaces intersect each other at a right angle (hereinafter referred to as a direction). A strip-shaped directional screen 91 (having a width in the a direction as w) is prepared (Fig. 9 (b)), and is included in 91 in the direction perpendicular to the a direction with reference to one 91 (referred to as 91-1). Another 91 (designated 91-2) rotated by an angle θ around the b-axis
(FIG. 9C), and the sides in the a direction of 91 are brought into contact with each other with the b axis as a reference (FIG. 9D). Next, another 91 (referred to as 91-3) rotated by an angle θ around the b-axis with reference to 91-2 is used to bring the sides of 91-2 in the a-direction into contact with each other with the b-axis as a reference (Fig. 9 (e)). A structure in which this is repeated n times (n is an integer of 2 or more), and then the angle is changed to −θ and repeated n times is referred to as an A structure 92 (FIG. 9).
(F)). The directional screen 81 has a structure in which a plurality of A structures 92 are prepared and the sides in the a direction are in contact with each other. In this embodiment, the b-axis is set at the midpoint of the side in the a direction. The a-direction and the b-direction of the directional screen 81 are set parallel to the y-direction and the x-direction of FIG. 8, respectively. In the cross section of the directional screen 81 in the b direction, two adjacent surfaces intersect each other at right angles, so that the light incident on the screen 81 is x
In the z-plane, the light is reflected in the same direction as the incident direction. Therefore, the respective images (lights) projected from the respective projectors 11 and 12 are reflected by the screen 81 and then returned in the direction of the respective projectors within the xz plane. The cross section of the directional screen 81 in the a direction is a cross section of a reflecting mirror (here, a spherical reflecting mirror) having a curvature, and the radius of curvature in the a direction cross section at any position is constant. The position of the center of curvature of the reflecting mirror changes in the a direction depending on the position in the b direction, as described in the structure of the directional screen 81. Therefore, for each image (light) projected from each projector 11, 12, the screen 81 plays the role of a spherical reflecting mirror in the xz plane. The spherical reflecting mirror reflects light that is incident non-parallel to the optical axis symmetrically with respect to the optical axis. Therefore, the position of the center of curvature of the reflecting mirror changes in the a direction depending on the position in the b direction. In 81, the reflection direction is vertical (a) depending on the position of incident light (b direction).
Direction). As a result, as shown in FIG. 8, each image (light) projected from each projector 11, 12
After being reflected by the screen 81, the reflection direction fluctuates in the yz plane depending on the position of each incident light. Therefore, the width w of the strip type directional screen 91 is set to the screen 81.
If it is made very small with respect to the width in the b direction, the image can be recognized even if not all the light is reflected in the direction of the observer 15.
Moreover, the image can be always recognized even if the observer moves the face up and down. The width w is determined by the size of the screen 81, the distance between the screen 81 and the observer, the required fineness of the image, and the like.

As shown in FIG. 10, since the left-eye image enters only the left eye of the observer 15 and the right-eye image enters only the right eye of the observer 15, the observer reflects on the directional screen 81. You can feel a two-dimensional image as a three-dimensional image with depth.

Further, by placing the semi-transparent mirror 61 in the optical path as shown in FIG. 11, the optimum position for observing the projected image can be removed from the lines of the projectors 11 and 12 and the directional screen 81. You can make it easier to see.

In the above description, two projectors 11 and 12 are used, but the number of projectors is not limited to two. M cameras (m is an integer of 3 or more) are arranged side by side, and the same object is photographed with a reversal film to make a slide.
The slides are projected by the m projectors 71 as shown in FIG. 12 in the same order as when they were shot. Of course, it does not have to be a slide, and for example, a similar image may be projected by a liquid crystal projector or the like. Considering any two adjacent projectors of the m projectors 71, the image from the projector on the left side of the pair is the left-eye image, and the image from the projector on the right side is the right-eye image. Observer 15 by directional screen 81
You can feel the two-dimensional image reflected in the image as a three-dimensional image with depth. Therefore, even if the observer moves in the lateral (x) direction, new images from a pair of projectors can be successively put in each eye, so that the observer's lateral viewpoint moving range can be expanded. It is of course possible to put a semi-transparent mirror in the optical path and take out the optimum observation position from the line of the projector and the directional screen 81.

[0023]

According to the present invention, in a pseudo three-dimensional display system using binocular parallax, a directional screen having the properties of a directional reflection in the horizontal direction and a condenser mirror in the vertical direction is provided. Thus, there is an effect that a large and bright stereoscopic image can be displayed to the observer. Further, there is provided a pseudo stereoscopic display system capable of widening the vertical movement range of the observer without requiring a plurality of projectors in the vertical direction.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a pseudo stereoscopic display system according to the present invention.

FIG. 2 is a top view illustrating the principle of obtaining a stereoscopic effect by using binocular parallax.

FIG. 3 is an explanatory diagram showing a conventional example of a projection type three-dimensional image system.

FIG. 4 is a side view illustrating a screen that constitutes a pseudo-stereoscopic display method according to the present invention.

FIG. 5 is a top view illustrating the principle of the pseudo stereoscopic display method according to the present invention.

FIG. 6 is a top view showing an application example of the pseudo stereoscopic display method according to the present invention.

FIG. 7 is a top view showing an application example of the pseudo stereoscopic display method according to the present invention.

FIG. 8 is a perspective view showing a second embodiment of the pseudo stereoscopic display system according to the present invention.

FIG. 9 is a principle diagram illustrating a screen that constitutes a pseudo-stereoscopic display method according to the present invention.

FIG. 10 is a top view illustrating the principle of the pseudo stereoscopic display method according to the present invention.

FIG. 11 is a top view showing an application example of the pseudo-stereoscopic display method according to the present invention.

FIG. 12 is a top view showing an application example of the pseudo stereoscopic display method according to the present invention.

[Explanation of symbols]

11 and 12 are projectors 13 is a directional screen 14 is the fine adjustment stage 15 is an observer 41 is the optical axis 61 is a semi-transparent mirror 71 is a projector 81 is another directional screen 91 is a strip type directional screen 92 is structure A.

Front page continuation (72) Inventor Kazutaka Tsuji 1-280, Higashi Koikeku, Kokubunji, Tokyo, Central Research Laboratory, Hitachi, Ltd. (72) Inventor Yoshiyuki Kaneko 1-280, Higashi Koikeku, Kokubunji, Tokyo Hitachi, Ltd. Chuo In-house (72) Inventor Akihiko Kogami 1-280 Higashi Koikeku, Kokubunji, Tokyo Inside Hitachi Central Research Laboratory (72) Inventor Kimio Tateno 1-280 Higashi Koikeku, Kokubunji, Tokyo Inside Hitachi Research Laboratory (56) ) Reference JP-A-55-106416 (JP, A) JP-B-51-13410 (JP, B1) JP-B-52-50538 (JP, B1) (58) Fields investigated (Int.Cl. ⁷ , DB) Name) G03B 35/20

Claims (3)

(57) [Claims] 1. An image generation means for simultaneously generating images of the same object from different directions, and a display section on which the image information is projected or projected, and the image is sensed as a stereoscopic image by a viewer's binocular parallax. In the pseudo-stereoscopic image display device, the display section has a directivity in the horizontal direction and a curvature in the vertical direction in the same direction as the incident direction of light.
It is equipped with a reflector that collects and reflects light by putting
Installed with the optical axis of the vertical section of the reflecting mirror facing upward
A pseudo three-dimensional image display device characterized by being provided . 2. The pseudo three-dimensional body according to claim 1, wherein the reflection mechanism is a prism having an apex angle of 90 degrees, and the display section has a curvature in a plane perpendicular to a plane including the apex angle of 90 degrees. Image display device. 3. The pseudo-stereoscopic image display device according to claim 2, wherein the center of curvature of the display section changes depending on the position of the display section.