JP2000187433A - Method and device for recording stereoscopic video, and storage medium recorded with lens moving program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stereoscopic video recording device capable of being used for a stereoscopic video display method using photorefractive crystal as a screen to project a video and efficiently recording a stereoscopic video in the photorefractive crystal. SOLUTION: This device has a light source 201, a splitting means 205 splitting light radiated from the light source into two optical paths, a first radiating means 206 directly radiating one light beam split by the splitting means to the photorefractive crystal 208, a second radiating means radiating the other light beam split by the splitting means to the photorefractive crystal through a lens 207, an inputting means inputting the data of a three-dimensional stereoscopic image displayed and controlling means 290 and 210 controlling a lens position so that the focal position of the lens coincides with one point on the surface of the three-dimensional stereoscopic image displayed based on the data from the inputting means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stereoscopic video recording method, a stereoscopic video recording apparatus, and a recording medium on which a lens moving program is recorded. The present invention relates to a technique effective for recording interference fringes of light in a reflective crystal.

[0002]

2. Description of the Related Art As a method for displaying an object three-dimensionally, there are a method using stereoscopic vision, a method using a hologram, and the like. The former method in which stereoscopic vision is applied is a method in which images observed by the left and right eyes are separately projected onto the eyes, and only the observer can stereoscopically observe the display target. The latter method using a hologram is a method in which the wavefront of light reflected from an object is reproduced as it is.

[0003]

The major factors in which a person perceives an object three-dimensionally are binocular parallax and focus adjustment. The method that applies the stereoscopic vision is a method that reproduces only the binocular parallax, and the focus of the eye is always matched to the screen on which the image is projected, contrary to the pop-out effect of the object due to the binocular parallax. In addition, since the focus position is fixed, there is a problem that eye strain due to long-term observation cannot be avoided. On the other hand, the method using the hologram is the most ideal as a method of stereoscopic display, and can perform binocular parallax and focus adjustment as in the case of observing a real object.
However, in order to record a hologram, it is necessary to reproduce the light diffraction phenomenon, so that it is necessary to record several thousand stripes per millimeter. So far,
The hologram was a stereoscopic display system as a photograph. As a method for displaying a moving image using a hologram, a method using a liquid crystal panel has been proposed, but the displayable resolution (spatial frequency) of the liquid crystal panel is not sufficient for hologram display. That is, since the resolution is low and the gray value that can be displayed is restricted, it is not enough to display a complicated fringe like an actual hologram. Therefore, when attempting to display a hologram using these electronic devices, only a small number of small objects (point light sources) can be displayed. In addition, since the resolution is low, it is difficult to separate the light directly transmitted through the liquid crystal panel from the diffracted light, and there is a problem that the observation area is narrow. The present invention has been made in order to solve the problems of the prior art, and an object of the present invention is to:
It is an object of the present invention to provide a stereoscopic video recording method and apparatus used for a stereoscopic video display method that uses a photorefractive crystal as a screen for projecting a video and capable of efficiently recording a stereoscopic video on the photorefractive crystal. It is another object of the present invention to provide a recording medium on which a lens moving program used for executing the stereoscopic video recording method is recorded. The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0004]

SUMMARY OF THE INVENTION Among the inventions disclosed in the present application, the outline of a representative one will be briefly described.
It is as follows. In a photorefractive crystal, the refractive index of the crystal changes depending on the light irradiation intensity. for that reason,
It is mainly used as a holographic recording element.
By using this photorefractive crystal as a screen for projecting an image, a stereoscopic image can be displayed. That is, the lens position is controlled so that one point on the surface (contour, boundary surface, or the like) of the three-dimensional stereoscopic image to be displayed coincides with the focal position of the lens, and all the display target areas of the three-dimensional stereoscopic image to be displayed are displayed. Scan. Light condensed on the surface (contour, boundary surface, etc.) of the three-dimensional stereoscopic image through the lens is applied to the photorefractive crystal as a wavefront of light when a point light source is located at the focal position of the lens. At the same time, by irradiating the photorefractive crystal with reference light at different incident angles, interference fringes between the lens transmitted light and the reference light are generated in the photorefractive crystal, and these fringes are recorded inside the photorefractive crystal. You. After the scanning of the surface of the three-dimensional stereoscopic image to be displayed is completed, when the photorefractive crystal is irradiated only with the reference light, the interference fringes recorded on the photorefractive crystal become a diffraction grating, and the wavefront of the light from each focal position is changed. Will play.

That is, the focal position of the lens becomes a virtual point light source of a three-dimensional image to be displayed. Therefore, as shown in FIG. 7, the observer 10 looking into the photorefractive crystal 208 observes the diffracted light. In this case, the observer 10 perceives that the light goes straight ahead, and thus perceives the light as coming from the surface of the three-dimensional stereoscopic image 11 to be displayed, and recognizes the three-dimensional stereoscopic image 11 to be displayed as a three-dimensional image. be able to.

The present invention is a stereoscopic video recording method and apparatus for recording interference fringes on a photorefractive crystal for use in a stereoscopic video display method utilizing the photorefractive crystal as a screen for projecting an image. That is, the present invention relates to a stereoscopic image recording apparatus that records interference fringes of two lights having different incident angles in a photorefractive crystal capable of displaying a three-dimensional stereoscopic image by irradiating a reference light, Splitting means for splitting light emitted from the light source into two optical paths, first irradiating means for directly irradiating one of the light split by the splitting means to the photorefractive crystal, and splitting by the splitting means Second irradiating means for irradiating the other light to the photorefractive crystal through a lens, input means for inputting data of a three-dimensional stereoscopic image to be displayed, and a focal position of the lens based on the data from the input means. And a control means for controlling the lens position so that a point on the surface of the three-dimensional image to be displayed coincides. Further, the present invention is a stereoscopic video recording method for recording interference fringes of two lights having different incident angles inside a photorefractive crystal capable of displaying a three-dimensional stereoscopic video by irradiating a reference light, One of the two lights is directly irradiated on the photorefractive crystal, and the other of the two lights is a position-adjustable lens, the focal position of the lens and one point on the surface of the displayed three-dimensional stereoscopic image. By irradiating the photorefractive crystal through a lens whose lens position is moved such that the two light beams coincide with each other, interference fringes of the two lights are recorded inside the photorefractive crystal. In addition, the present invention provides a photorefractive crystal capable of displaying a three-dimensional stereoscopic image by irradiating a reference light, wherein the incident angles are different from each other.
A stereoscopic video recording method for recording two light interference fringes,
One of the two lights is directly irradiated on the photorefractive crystal, and at the same time, the other of the two lights is a position-adjustable lens, the focal position of the lens and the surface of the displayed three-dimensional stereoscopic image. An interference fringe of two lights generated when irradiating the photorefractive crystal through a lens whose lens position is moved so that one point coincides is displayed on an electronic display device, and the two light beams displayed on the electronic display device are displayed. The interference fringes are recorded inside the photorefractive crystal. The present invention is also a stereoscopic image recording method for recording interference fringes of light in a photorefractive crystal capable of displaying a three-dimensional stereoscopic image by irradiating a reference light, wherein two light beams having different incident angles are provided. Is directly irradiated on the photorefractive crystal, and at the same time, the other of the two lights is adjusted so that the focal position of the lens coincides with a point on the surface of the displayed three-dimensional stereoscopic image. When a plurality of interference fringes of two lights generated when the photorefractive crystal is irradiated through the lens are displayed, the interference fringes are displayed on the electronic display device, and the interference fringes displayed on the electronic display device are recorded inside the photorefractive crystal. It is characterized by doing. Further, the present invention is a recording medium for recording a lens moving program for moving a lens position by a computer, which is used in the stereoscopic video recording method.

[0007]

Embodiments of the present invention will be described below in detail with reference to the drawings. In all the drawings for describing the embodiments, components having the same functions are denoted by the same reference numerals, and repeated description thereof will be omitted. [First Embodiment] FIG. 1 is a block diagram showing a schematic configuration of a stereoscopic video recording apparatus according to a first embodiment.

The stereoscopic video recording apparatus according to the present embodiment uses laser light as light for recording. The laser light emitted from laser 201 is converted into spherical wave 211 by spatial filter 202. Is done. The spherical wave 211 is converted into a plane wave 212 by the lens 203, and the plane wave 212 is converted by the beam splitter 2.
05 splits into two plane waves, a plane wave 213 and a plane wave 214. One of the plane waves 213 split by the beam splitter 205 is converted into a spherical wave 215 again by the lens 207, and the wave front is irradiated on the photorefractive crystal 208. Beam splitter 20
The other plane wave 214 divided by 5 is reflected by the mirror 206 and applied to the photorefractive crystal 208 as reference light.

FIG. 2 is a diagram showing a processing procedure of the stereoscopic video recording apparatus according to the first embodiment of the present invention. Hereinafter, a processing procedure of the stereoscopic video recording device of the present embodiment will be described. First, the vertex data of the display target three-dimensional object is input to the display target data management unit 210 by the input unit (not shown) (step 101). The vertex data is obtained by modeling a three-dimensional shape in a computer, decomposing the surface of the display target three-dimensional object into fine meshes, and using a vertex data of each mesh. Actual display target 3 measured by measuring equipment
Surface coordinate data of a three-dimensional object may be used. Next, in order to display the three-dimensional stereoscopic image of the three-dimensional object to be displayed in a predetermined space, the display object data management means 210 converts the vertex coordinates of the three-dimensional object to be displayed into the coordinate system of the display object space. (Step 102). For example, a subspace including all the three-dimensional objects to be displayed is set in the world coordinate system of the original data, and the local coordinate system of the subspace is set as the coordinate system of the display target space. Next, data (display vertex coordinates) of the three-dimensional stereoscopic image to be displayed is sequentially read (step 103).

Next, the lens position control means 209 determines (x, y,
z) The lens position is moved based on the coordinate values so that the surface position of the three-dimensional stereoscopic image to be displayed matches the focal position of the lens 207 (step 104). Next, a laser beam is irradiated (step 105). Here, the plane wave 21
3 is transmitted through the lens 207 after the movement and the transmitted light is applied to the photorefractive crystal 208,
The reference light (plane wave 214) is also a photorefractive crystal 2
08. As a result, interference occurs between the transmitted light and the reference light, and interference fringes (stationary waves) are generated in the photorefractive crystal 208. Photorefractive crystal 20
In No. 8, the refractive index changes according to the stationary wave, and is recorded as interference fringes. Steps 103 to 105 are repeated until there is no more data of the three-dimensional stereoscopic image to be displayed (step 106). Thus, interference fringes of the wavefront generated by the plurality of point light sources are multiplex-recorded on the photorefractive crystal 208. After scanning the data of the displayed three-dimensional stereoscopic image, the lens transmitted light 215 is blocked, and only the reference light (plane wave 214) is irradiated (step 107), and observation is made so as to look into the photorefractive crystal 208. Thereby, a three-dimensional stereoscopic image can be observed. In step 107, the photorefractive crystal 208 is removed from the recording system,
Another reference light may be emitted at the same angle as during recording.

The display object data management means 21
0 and the lens position control means 209 can also be constituted by a computer. In this case, the display object data management means 210 and the lens position control means 209
Is a function realizing means executed by a lens moving program stored in the main memory. The lens moving program is provided by a recording medium such as a CD-ROM, for example.

FIG. 3 is a diagram for explaining an example of position control of the lens 207 shown in FIG. By moving the position of the lens 207 back and forth, the focal length moves back and forth, and as a result, the wavefront of the light applied to the photorefractive crystal 208 changes. For example, if the lens 207 is 3
01, an interference fringe such that light is condensed at the position of the focal length 302 is formed on the photorefractive crystal 20.
8 will be recorded. That is, when looking into the photorefractive crystal 208, an image having a point light source at the position 302 can be observed. Also, lens 2
By rotating 07 as in 303, it is possible to reproduce point light sources having different positions as well as the focal length. In FIG. 3, 312 and 313 are lenses (20
7, 303). Also, as shown in FIG. 4, the lens 207 is attached to an arm (401, 402, 403) movable in the (x, y, z) axis direction, so that the focal length and the position in space can be freely moved. Can be done. As described above, in the present embodiment, the coherent light is divided into two optical paths using the device configuration of the interferometer. Since the divided light has the same wavelength and phase, it has good coherence. Therefore, in this embodiment, interference fringes can be efficiently recorded.
Although the recording time changes depending on the intensity of the photorefractive crystal 208 and the irradiation light, in the present embodiment, the light utilization efficiency can be increased by condensing the light with the lens 207, and the recording time can be reduced. can do.

[Embodiment 2] In the above embodiment, the lens 207 is moved to change the focal length and position. In the above embodiment, the interference fringes (stationary waves) due to the interference between the transmitted light and the reference light are represented by the shading pattern of the Fresnel lens (so-called concentric shading image).
Becomes Therefore, in the present embodiment, for example, on an electronic display device such as a liquid crystal display device, a grayscale pattern of a Fresnel lens when the focal length and position are sequentially changed is displayed, and the grayscale pattern of the Fresnel lens is displayed as a photo. Irradiation is performed on the refractive crystal 208. The interference fringes generated in the photorefractive crystal 208 are recorded on the photorefractive crystal 208,
The reference light is diffracted by the recorded interference fringes and displayed 3
Light from a three-dimensional image is reproduced. A display device itself such as a liquid crystal display device has a limit in resolution and the like, and cannot directly display a normal hologram in which complicated interference fringes are recorded. However, the photorefractive crystal 208 has a resolution sufficient to record a hologram. In one display, the electronic display device displays, for example, a wavefront pattern of light generated by only one point light source.

In this case, it is only necessary to present a shading pattern of the Fresnel lens as shown in FIG. 5, and the reproduction can be performed even if the spatial frequency (resolution) of the display device is low. FIG.
FIG. 3 is a diagram illustrating an example of interference fringes displayed on an electronic device in the stereoscopic video recording method according to the present embodiment. Reference numeral 501 shown in the figure denotes a tone pattern of a Fresnel lens having a focal point near the central axis, and reference numeral 502 denotes a tone pattern of a Fresnel lens whose focal position has been moved. The focal position of the Fresnel lens corresponds to a point light source, and by sequentially displaying the light and shade patterns in which the position of the point light source is changed and recording the same on the photorefractive crystal 208, the moved point light source is moved on the photorefractive crystal 208. The wavefront of the light emitted from each is multiplex-recorded in the form of interference fringes.

Instead of displaying the shading pattern of the Fresnel lens, wavefronts from a plurality of points on the surface of the three-dimensional image to be displayed are calculated, and the wavefronts and plane waves (irradiation light) are calculated.
Alternatively, the light and shade pattern generated by step 214 may be obtained and displayed on the electronic device. That is, assuming that there are a plurality of point light sources on the surface of the three-dimensional stereoscopic image, interference fringes generated by these point light sources may be obtained by calculation, and the interference fringes may be displayed on an electronic device or the like.

FIG. 6 shows an example of interference fringes generated by assuming that a plurality of point light sources are present on the surface of a three-dimensional stereoscopic image.

The photorefractive crystal 208
It is possible to erase recorded interference fringes by irradiating a plane wave, and to reproduce a moving image by repeating recording and erasing.

As described above, the invention made by the present inventor is:
Although a specific description has been given based on the above-described embodiment, the present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made without departing from the gist of the invention.

[0019]

The effects obtained by typical ones of the inventions disclosed in the present application will be briefly described as follows. (1) According to the present invention, it is possible to efficiently record light interference fringes on a photorefractive crystal. (2) According to the present invention, since the light use efficiency can be increased, it is possible to shorten the recording time when recording the light interference fringes on the photorefractive crystal. (3) By using the photorefractive crystal according to the present invention, it is possible to display a true stereoscopic image with vertical and horizontal parallax. (4) According to the present invention, a moving image can be displayed using a photorefractive crystal by rewriting the interference fringes of light recorded on the photorefractive crystal at a high speed.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a schematic configuration of a stereoscopic video recording device according to a first embodiment.

FIG. 2 is a diagram illustrating a processing procedure of the stereoscopic video recording device according to the first embodiment of the present invention.

FIG. 3 is a diagram for explaining an example of position control of the lens shown in FIG. 1;

FIG. 4 is a diagram showing an example of an apparatus for moving the lens shown in FIG. 1 in the (z, y, z) axis direction.

FIG. 5 is a diagram illustrating an example of interference fringes displayed on an electronic device in the stereoscopic video recording method according to the second embodiment of the present invention.

FIG. 6 is a diagram showing another example of interference fringes displayed on an electronic device in the stereoscopic video recording method according to the second embodiment of the present invention.

FIG. 7 is a diagram for explaining a three-dimensional stereoscopic image display method using a photorefractive crystal.

[Explanation of symbols]

10: observer, 11: three-dimensional stereoscopic image to be displayed, 201:
Laser, 202: spatial filter, 203: lens, 204: mirror, 205: beam splitter, 2
06: mirror, 207, 301, 303: movable lens,
208: photorefractive crystal, 209: lens position control hand-drawing, 210: display object data management means, 30
1 ... movement position of lens 207, 302 ... focal length of lens 207, 303 ... rotated lenses 207, 401,
402, 403... Arms for moving the lens 207.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kazuto Higuchi 3-19-2 Nishi-Shinjuku, Shinjuku-ku, Tokyo Within Japan Telegraph and Telephone Corporation (72) Inventor Noboru Sonehara 3--19, Nishishinjuku, Shinjuku-ku, Tokyo No. 2 Nippon Telegraph and Telephone Corporation F term (reference) 2H059 AC04 2K008 AA04 BB06 DD23 EE01 FF07 HH06 HH18 HH26

Claims (5)

[Claims] 1. A stereoscopic video recording apparatus for recording interference fringes of two lights having different incident angles inside a photorefractive crystal capable of displaying a three-dimensional stereoscopic image by irradiating a reference light, comprising: a light source; A dividing unit that divides light emitted from the light source into two optical paths; a first irradiating unit that directly irradiates one of the lights divided by the dividing unit to a photorefractive crystal; Second irradiating means for irradiating the other light to the photorefractive crystal through a lens, input means for inputting data of a three-dimensional stereoscopic image to be displayed, and a focal position of the lens based on the data from the input means. Control means for controlling the lens position so that one point on the surface of the three-dimensional stereoscopic image to be displayed coincides with the point. 2. A stereoscopic video recording method for recording interference fringes of two light beams having different incident angles in a photorefractive crystal capable of displaying a three-dimensional stereoscopic image by irradiating a reference light beam, wherein: One of the two lights is directly radiated to the photorefractive crystal, and the other of the two lights is a position-adjustable lens, the focal position of the lens and one point on the surface of the three-dimensional stereoscopic image to be displayed. A three-dimensional video recording method comprising: irradiating a photorefractive crystal through a lens whose lens position is moved such that the two coincide with each other, thereby recording the interference fringes of the two lights inside the photorefractive crystal. 3. A stereoscopic video recording method for recording interference fringes of two light beams having different incident angles inside a photorefractive crystal capable of displaying a three-dimensional stereoscopic image by irradiating a reference light beam. One of the two lights is directly radiated to the photorefractive crystal, and the other of the two lights is a position-adjustable lens, the focal position of the lens and one point on the surface of the three-dimensional stereoscopic image to be displayed. The interference fringes of two lights generated when the photorefractive crystal is irradiated through a lens whose lens position is moved so that the two coincide with each other are displayed on an electronic display device, and the interference fringes of the two lights displayed on the electronic display device are displayed. A stereoscopic video recording method characterized by recording the image in a photorefractive crystal. 4. A stereoscopic image recording method for recording interference fringes of light in a photorefractive crystal capable of displaying a three-dimensional stereoscopic image by irradiating a reference light, wherein the two light beams have different incident angles. One lens is directly irradiated on the photorefractive crystal, and at the same time, the other of the two lights is adjusted so that the focal position of the lens coincides with one point on the surface of the three-dimensional image to be displayed. When a plurality of interference fringes of two lights generated when the photorefractive crystal is irradiated with light through the device are displayed on the electronic display device, the interference fringes displayed on the electronic display device are recorded inside the photorefractive crystal A stereoscopic video recording method characterized in that: 5. A stereoscopic video recording method for recording interference fringes of two light beams having different incident angles inside a photorefractive crystal capable of displaying a three-dimensional stereoscopic image by irradiating a reference light beam, wherein: One of the two lights is directly radiated to the photorefractive crystal, and the other of the two lights is a position-adjustable lens, the focal position of the lens and one point on the surface of the three-dimensional stereoscopic image to be displayed. Irradiating the photorefractive crystal through a lens whose lens position is moved such that the two coincide with each other, thereby recording the interference fringe of the two lights inside the photorefractive crystal by a computer. A recording medium storing a lens moving program for moving the lens, wherein the lens moving program comprises: A step of controlling the lens position based on the input data of the three-dimensional stereoscopic image to be displayed so that the focal position of the lens coincides with a point on the surface of the three-dimensional stereoscopic image to be displayed. A recording medium in which a lens moving program is recorded, the program being executed for all points on the surface of a three-dimensional stereoscopic image to be displayed.