JPS6131468B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a hologram by which a reproduced color image can be obtained.

The plurality of pieces of color image information used in this specification refers to color image information for so-called searching pictures, in which different pictures can be observed by changing the viewpoint during playback, or color images for stereoscopic viewing. This information is information, etc., and will be explained below as color image information for stereoscopic viewing. Also, to explain the composite hologram, first, as shown in Figure 1, an object 1 is
is recorded on the recording medium _{3 1 .} . . _{3 4 by} the imaging lens 2 1 _. Fix it and get picture elements 4 ₁ ......4 ₄ . Furthermore, the first
In the case of the figure, each recording medium 3 ₁ ......3
Picture element ₄ obtained because the object is recorded in 4 ₁ ...
...4 ₄ is called a three-dimensional picture element. Next, one of the picture elements ₄₁ ... ₄₄ thus obtained (picture element ₄₂ is shown in FIG. 2) is passed through the diffuser plate 5. , illuminated with monochromatic coherent light, the transmitted light of the picture element ₄₂ is made incident on a part of the hologram recording body 8 of one sheet or one frame through the slit 7, and the reference light 9 is made incident therewith.
Next, another picture element ₄₁ is illuminated with the coherent light 6, and the slit 7 is moved to record on another part of the hologram recording medium 8. In this way, each picture element 4 ₁ ...
… ₄ The information recorded on the holographic image 7 is called a composite hologram, and each picture element 4 ₁ ………4 ₄
A hologram corresponding to is called an element hologram.
However, since this hologram was created using monochromatic coherent light, only a monochromatic reconstructed image can be obtained.

In order to obtain a color reproduction image, it is sufficient to make the pixels into color positives and create a composite hologram using red, green, and blue coherent light. However, as described in Japanese Patent Application No. 15339/1989, previously filed by the present applicant, color composite holograms have had problems such as color shift in the reproduced image due to crosstalk images during reproduction. This problem was solved by the invention described in Japanese Patent Application No. 15339/1983.

The gist of this invention is that during reproduction, a plurality of color information light beams limited by the aperture of the recording system are recorded such that there is a portion where the false aperture reproduced image due to crosstalk does not overlap with the true aperture reproduced image. When the color information is reproduced by illuminating the hologram with a plurality of wavelengths, an aperture of the reproduction system is provided in a portion where a false image due to crosstalk is not superimposed on the true aperture reproduction image. This is a color holographic reproduction method characterized by extracting true color element information corresponding to each illumination wavelength light using In addition, since multiple pieces of color information are separated from each other and recorded due to the difference in the pitch of the carrier interference fringes, during playback, the illumination light of each color is all directed in the same direction. The crosstalk image can be aligned and incident on the hologram surface in the direction perpendicular to the direction of the carrier interference fringes (i.e. the direction in which the interference fringes are lined up).
Therefore, in the direction of the carrier interference fringes, a large aperture for separating the crosstalk image must be made;
In stereoscopic image reproduction, there is a kind of advantage in that the parallax in this direction can be increased.

The present invention utilizes the previous invention in a synthetic color hologram reproduction method to effectively utilize the previous invention to perform color three-dimensional reproduction.

Next, one embodiment of the present invention will be described based on FIG.

A three-dimensional picture element ₁₀₁ made of a color positive film is simultaneously illuminated with coherent light R, G, and B of three different wavelengths through a diffuser plate 11. The light diffracted from this 3D picture element ₁₀₁ is directed through the aperture 12 placed behind it in a direction in which each 3D picture element is arranged corresponding to its viewpoint (this direction is hereinafter referred to as the parallax direction of the 3D picture element). A hologram recording medium 1 is created by restricting the space and further restricting the space in a direction perpendicular to the parallax direction of the three-dimensional picture elements by an aperture 13 placed behind the aperture 13.
Irradiate to 4. At the same time, the coherent light containing these three color information and the reference light R'G'B' for creating a hologram, which interferes with each other, form interference fringes on the dry plate surface 14, and the direction of the interference fringes becomes almost parallel to the parallax direction of the three-dimensional picture elements. The incident angle of the light is selected as shown in FIG. Such an incident angle is such that the direction cosine of the stereoscopic picture element in the parallax direction is zero. The reference light R′G′B′ consists of three wavelength lights, and the incident angles of these three lights can be the same or different, but it is better to have the optical arrangement in the same direction during hologram shooting and reproduction. It gets easier.

Hologram photography using each wavelength of light may be performed simultaneously using three wavelengths of light as described above, or may be performed using a multiple exposure method using three wavelengths of light sequentially.

After performing color hologram photography for the first picture element, the first picture element ₁₀₁ is replaced with a color positive film ₁₀₂ of the second three-dimensional picture element, and the three-dimensional information restriction aperture 12 is inserted into the three-dimensional picture element 102. Double exposure is performed on the same dry plate surface 14 on which the first three-dimensional picture element ₁₀₁ was recorded by moving it to a position corresponding to the _second viewpoint.
By repeating the above operations for each three-dimensional picture element, a composite hologram in which color information is recorded is produced.

The thus obtained composite hologram is illuminated with three coherent beams 17 having different wavelengths from a direction opposite to the direction of incidence of the reference beams of each wavelength during hologram production. At that time, as shown in FIG. 5, concentration filters 17 ₁ , 17 ₂ , 17
₃ so that you can adjust the color balance,
It is necessary to superimpose the three wavelength holes using the mirror 8 and beam splitters 19 and 20 so that they travel in almost the same direction.

In addition, since general multi-wavelength oscillation lasers also oscillate light with wavelengths other than the three primary color wavelengths, in order to remove them, the emitted light 21 from the laser is
is separated into three colors by the three-color separation optical system 22, and the corresponding color filters 23 ₁ , 23 ₂ , 23 ₃
is applied to extract the desired single wavelength light and input it into the three-color synthesis optical system shown in FIG. will be played. As shown in FIG. 7, the aperture image generally consists of false aperture reconstruction images 24 ₁ , 24 ₂ . . . 24 ₆ superimposed on the true aperture reconstruction image 25. That is, the hologram obtained by the above method consists of element holograms corresponding to each of the three color lights, and when these element holograms are illuminated with the three color lights, a combination of elements that correspond correctly and those that do not correspond to each element hologram and each illumination light is created. occurs. The former gives a true aperture reconstruction image 25, and the latter gives a false reconstruction. For example, a combination in which an element hologram of red information is illuminated with red light will give a true aperture reconstruction, and a combination in which it is illuminated with green or blue light will give a false aperture reconstruction.
The false aperture reproduction image becomes harmful noise in the case of color reproduction and is called a color crosstalk image. The true aperture reconstructed image 25 is a superposition of three true aperture reconstructed images corresponding to three colors.

The hologram is created so that the carrier interference fringes of each element hologram occurring on the hologram surface are almost parallel to the parallax direction of the 3D picture element, so the color crosstalk image is parallel to the parallax direction of this 3D picture element. The deviation is approximately vertical, and the amount of deviation is determined by the wavelength ratio of the three wavelengths and the spatial frequency (number/mm) of the hologram carrier interference fringes. Now, if the amount of deviation between the true aperture reconstructed image 25 and the two crosstalk images that occur closest to the true aperture reconstructed image 25 are d ₁ and d ₂ , then the aperture size a is smaller than (d ₁ + d ₂ ). By taking this, it is possible to create a portion in the true aperture reconstructed image where the crosstalk images do not overlap.

Therefore, by placing the reproduction aperture 26 in that part, the crosstalk aperture images 24 ₁ , 24 ₂ . . .
... ₂₄₆ can be separated from the information that gives the true reconstructed image. In order to use the amount of illumination light most effectively during reproduction, it is preferable to prevent the crosstalk image from overlapping the true aperture reproduction image at all. That is, d ₁ >
It is desirable to determine the aperture size a and the spatial frequency of the hologram carrier so that the condition a, d ₂ > a is satisfied, and use an aperture of the same size as the true aperture reconstructed image as the reproduction aperture. .

As shown in FIG. 4, behind the reproduction aperture 26 are a plurality of three-dimensional information limiting aperture images 27 that are multiplex recorded on a hologram corresponding to each three-dimensional picture element.
₁ , 27 ₂ , 27 ₃ . In order to view this color reproduced image stereoscopically, a lens screen 28 such as a Fresnel lens is placed near the image plane, and when the eyes are placed on a plane 29 that is conjugate with the aperture image 27 for limiting stereoscopic information, the left and right eyes have different images. A color stereoscopic image 30 containing parallax information can be observed. At this time, the viewing area is restricted by the color information restriction aperture 26 in the direction perpendicular to the parallax direction of the three-dimensional picture elements, so in order to expand the viewing area in that direction, light is directed in one direction by overlapping the lens screen. For example, a lenticular plate 31 made of closely arranged microcylindrical lenses may be placed to diffuse the light. A combination of a lenticular plate and a Fresnel lens that has the same function as shown in Figure 8 is a combination of a one-dimensional Fresnel lens that has an image-forming effect in one direction and a lenticular plate that has a diffusion effect in a direction perpendicular to the one-dimensional Fresnel lens. A unidirectionally diffusive one-dimensional Fresnel lens 32 may be used, or a unidirectionally diffusive lens 33 as shown in FIG. 9, which is an integrated lens and lenticular plate, may be used. These screens that have imaging properties (or directivity) in one direction and diffusion properties in the other direction are a type of stereoscopic screen, and there are several other screens of this type.

In the above embodiment, the color information restriction aperture 13 is placed behind the stereoscopic information restriction aperture 12, but the color information restriction aperture 13 does not necessarily have to be arranged in this order, and may be arranged in the opposite order. Further, the present invention can be practiced even if both openings are provided on the same surface. Furthermore, it is not necessary that both apertures exist between the three-dimensional picture element 10 and the dry plate 14, and as shown in FIG. It is also possible to form an image. Furthermore, in the first embodiment, during reproduction, the stereoscopic information limiting aperture image 27 and the color information limiting aperture image 25 are reproduced between the hologram surface 16 and the reproduced image 30 of the stereoscopic picture element. The arrangement is not limited, and any arrangement shown in FIGS. 11 to 14 can be used. 11th
In the figure, an aperture image 25 for color information restriction is reproduced on one side of the hologram 16, an aperture image 27 for three-dimensional information restriction is reproduced on the other side, and an aperture 26 is reproduced behind the aperture image 25 for color information restriction.
is provided to block the crosstalk image 24, and this opening 2
Regarding 6, a stereoscopic screen 40 is placed near the stereoscopic pixel image 30 that is reproduced as a real image on the opposite side from the hologram 15, and the color stereoscopic image 30 is observed in the plane 29 that is conjugate with the stereoscopic information limiting aperture image 27. This is an example.

FIG. 13 shows that the three-dimensional pixel image 30, the three-dimensional information limiting aperture image 27, and the color information limiting aperture image 25 are reproduced as virtual images on one side of the hologram 16.
The imaging lens 41 placed on the other side forms these three types of images as a real image, and an aperture 26 is placed behind the real image 25' of the color information limiting aperture image 25 to block the color-related crosstalk image 24. In this example, a stereoscopic screen 40 is placed near the stereoscopic picture element image 30', and the color stereoscopic image 30' is observed from the real image plane 29 of the stereoscopic information limiting aperture formed by the screen.

FIG. 13 shows a stereoscopic pixel image 30 near the hologram 15, a stereoscopic information limiting aperture image 27 on the viewing side of the hologram 15, and a color information limiting aperture image 25 on the opposite side of the hologram 15 from the viewing side. In the case of reproduction, an imaging lens 41 is placed near the stereoscopic information limiting aperture image 27, and this lens projects the stereoscopic pixel image 30 onto the stereoscopic viewing screen 40 while simultaneously projecting the color information limiting aperture image 25 into the space. are formed as a real image 25'. An aperture 26 behind this real image 25' for removing the color crosstalk image 24'
The stereoscopic pixel image 3 is projected from the vicinity of the stereoscopic information limiting aperture image 29 formed by the stereoscopic vision screen 40 to the vicinity of the stereoscopic vision screen 40.
By observing 0', a color stereoscopic image can be reproduced.

Although the above embodiment was an example of observing a real image of a three-dimensional picture element reproduced from a hologram, it is also possible to observe a virtual image by using the optical arrangement shown in FIG. Regarding the hologram 15, the aperture image 25 for color information restriction and the aperture image 27 for three-dimensional information restriction are reproduced as real images on the viewing side, and the three-dimensional pixel image 30 is reproduced as a virtual image on the opposite side.

By providing the aperture 26 for removing the color crosstalk image 24 behind the color information limiting aperture image 25, the color stereoscopic image 30 can be observed from near the stereoscopic information limiting aperture image 25.

At this time, a wider field of view can be obtained by placing the color information limiting aperture 25 and the three-dimensional information limiting aperture 27 on the same plane.

Although the hologram described above is a Fournel transform type hologram, the present invention is not limited to this arrangement, and can be implemented as other Fourier transform type or imaging type holograms. The case of implementation as an imaging type hologram will be explained in FIG. 15. The three-dimensional picture elements 45 are arranged so that their images are formed on the holographic photographing photoreceptor 46 by the imaging lens 44, and the three-dimensional information is arranged in a direction corresponding to the viewpoint of the three-dimensional picture elements (three-dimensional picture elements). An aperture 47 that limits the color information to the direction of the parallax of the three-dimensional picture element (the original parallax direction) and an aperture 48 that limits the color information to the direction perpendicular to the direction of the parallax of the three-dimensional picture elements are provided.

This optical arrangement allows one three-dimensional picture element to be placed on the diffuser plate 4.
Three wavelengths of light 50 ₁ , 50 ₂ , 50 ₃ through 9
At the same time, reference beams 51 ₁ , 51 ₂ , 51 ₃ for holographic imaging are made incident on the dry plate 46 for holographic imaging from a direction that does not have a direction cosine in the parallax direction of the three-dimensional picture elements to perform holographic imaging. conduct.

Regarding other three-dimensional picture elements, the three-dimensional information limiting aperture 47 is moved to a position corresponding to the viewpoint of the picture element, and the holographic photographing dry plate 46 is subjected to multiple exposure. A feature of the imaging type hologram obtained in this manner is that image reproduction can be performed using quasi-monochromatic light such as that obtained by applying an interference filter to white light during reproduction. FIG. 16 shows an example of the regeneration method. The light emitted from the white light source 52 is collected onto a pinhole 54 by a condenser lens 53, and the light emitted from the pinhole 54 is made into parallel light by a collimator lens 55, and the three-color separation optical system 5
6, it is separated into three colors. An interference filter 57 that narrows the wavelength width of each of the three color separated lights.
_{1,57 2,57} Density filter 58 for further color balance adjustment by multiplying by _{3 1,58
2} , 58 ₃ , and then the three colors of light are combined by a reflecting mirror 59 and beam splitters 60 ₁ and 60 ₂ . Three color light 61 synthesized in this way
₁ , 61 ₂ , and 61 ₃ illuminate the hologram 62 from a direction opposite to that of the reference light used when producing the hologram. With such illumination, an image 64 of the three-dimensional information limiting aperture and an image 63 of the color information limiting aperture used in the hologram production are reproduced from the hologram 62. As the color information limiting aperture image 63, a false aperture image is also reproduced at the same time as the true aperture image. Therefore, as in the previous embodiment, only the true aperture image is separated from the others by the slit 65 and taken out. A reproduced image of the object information reproduced on the imaging hologram surface 62 or its vicinity by the imaging lens 66 is formed on the stereoscopic vision screen 67, and the stereoscopic information limiting aperture formed by the stereoscopic vision screen 67 is By viewing the lens screen surface 67 from the image surface 68 of the reproduced image 64, color stereoscopic viewing can be performed. The advantages of image reproduction using such quasi-monochromatic light are that three-dimensional image reproduction can be performed using a normal light source and that there is no noise called a speckle pattern that appears in reproduction using coherent light. Further, in this embodiment, the reason why the wavelength width is narrowed by applying an interference filter to the three-color light separated by the three-color separation system is to improve color reproducibility.

In the embodiment described above, one aperture for restricting color information is provided in the direction perpendicular to the parallax direction of the stereoscopic picture element, but a plurality of apertures are provided in this direction corresponding to each color information. The present invention can be carried out even if multiple openings are provided. An example is shown in FIG. One color positive three-dimensional picture element 69 ₁ is illuminated with laser light consisting of three wavelengths 70 ₁ , 70 ₂ , 70 ₃
A 3D information restriction aperture 71 that restricts the space in the parallax direction of the 3D picture element is placed behind it at a position corresponding to the viewpoint of the 3D picture element, and a 3D information restriction aperture 71 is placed behind it in a direction perpendicular to the parallax direction of the 3D picture element. Three apertures 71 ₁ , 72 ₂ , 73 ₃ are provided to limit the space, and each color filter 73 ₁ , 73 2 , 73 ₂ allows only one of the three wavelengths of light illuminating the three-dimensional picture elements to pass through.
₇₃₃ is installed, one color information corresponds to one aperture, and the three color information are separated and arranged in space. The object information light that has passed through these two types of apertures 71 and 72 is irradiated onto the holographic photographing sensitive material 74, and at the same time, the reference light 75 that interferes with the object information light is used to create a three-dimensional image as in the previous embodiment. Holographic imaging is performed by making the light incident on the holographic imaging sensitive material 74 from a direction that does not have the direction cosine of the original parallax direction. Other three-dimensional picture elements 69 ₂ , 69 ₃ ...
..., the three-dimensional information limiting aperture 71 is moved to a position corresponding to the viewpoint of the picture element, and the holographic photographing dry plate 74 is subjected to multiple exposure. The carrier interference fringes of the hologram obtained in this manner are almost parallel to the parallax direction of the three-dimensional picture elements. In addition to the method using the color filter mentioned above, there are other methods for separating and arranging the three color information in space.
It is also possible to sequentially illuminate the three-dimensional picture element with light of each wavelength, move the slit aperture for limiting color information in a direction perpendicular to the parallax direction of the three-dimensional picture element each time, and perform holographic imaging using a multiple exposure method.

A color three-dimensional display can be produced from the hologram thus obtained by using the arrangement shown in FIG. When the hologram 76 is illuminated with polychromatic light 77, a reproduced image 78 of the aperture for limiting color information and a reproduced image 79 of the aperture for limiting stereoscopic information recorded during holographic imaging are obtained. The color information limiting aperture image consists of three correct images and false aperture images attached to each. This false aperture image is created as a result of illuminating one color element hologram with polychromatic light other than the wavelength light corresponding to it, and as a result of one illumination light corresponding to a color element hologram illuminating another element hologram. There are two types of things that can be done.
In each of the three true aperture images, interference filters 80 ₁ , 80 ₂ , 80 ₃ are included in the portions where the latter false aperture images do not overlap, allowing only the wavelength light corresponding to the aperture to pass through. Opening 81 ₁ ,
By providing 81 ₂ and 81 ₃ , the two types of false aperture images mentioned above can be blocked, and only the light beam forming the true aperture image can be taken out. This light flux forms a reproduced image 79 of the three-dimensional information limiting aperture, and then forms a color object image 82 in space. A stereoscopic screen 83 is placed near the surface on which the color object image 82 is formed, which has an imaging effect in the parallax direction of the stereoscopic picture elements and a diffusion effect in the vertical direction of the parallax.
This screen forms a reproduced image 79 of the three-dimensional information limiting aperture in space as a real image 84, and when the screen surface is viewed from here, a color three-dimensional image can be observed on the screen surface. Overlapping the interference filter 80, a density filter 85 ₁ ,
Color balance can be adjusted by placing filters 85 ₂ and 85 ₃ and changing the density of these filters. Comparing this embodiment with the previous embodiment using one color information limiting aperture, in the previous embodiment, the three colors shown in FIG. Although the separation optical system and the three-color synthesis system shown in FIG. 5 were required, in this embodiment, the polychromatic light is directly incident on the hologram, and only the three-color light is selected by the interference filters 80 ₁ , 80 ₂ , 80 ₃ , and the density filter 85 ₁ , 85 ₂ , and 85 ₃ have the advantage that color balance adjustment can be performed and the optical arrangement for illumination can be simplified.

In the embodiment described above, as a method of synthesizing a hologram from a plurality of three-dimensional picture elements, a slit aperture is placed in front of the holographic photographic sensitive material to limit the spread of the light flux in the parallax direction of the three-dimensional picture elements, and each of the apertures is A method has been used in which a composite hologram is created by multiple exposure holographic photography while moving the three-dimensional picture element to a position corresponding to the viewpoint, but the present invention is not limited to this method. The present invention can also be practiced by other methods as long as the information of each three-dimensional picture element is spatially separated and arranged in correspondence with parallax. As an example, an embodiment of the present invention for producing an imaging type hologram from a Fresnel hologram will be described with reference to FIG.

A color positive three-dimensional picture element 86 ₁ is exposed to three laser beams 88 with different wavelengths through a diffuser plate 87.
_{1,882,883 . _} Three apertures 90 ₁ , 90 ₂ , 90 ₃ are provided in a direction perpendicular to the parallax direction of the 3-dimensional picture element placed immediately in front of the hologram photographing sensitive material 89 to reflect the light diffracted from the 3-dimensional picture element. The spread of the diffracted light beam is restricted in the direction and the direction perpendicular to the direction, and the diffracted light beam is made incident on the sensitive material for holographic photography. At this time, in order to associate one color information with one aperture, color filters 91 ₁ , 91 ₂ , 91 are used that allow only one wavelength of light to pass through each aperture.
Further, appropriate density filters 92 ₁ , 92 ₂ , _{92 3 are} provided in each aperture so as to adjust the balance of brightness of each wavelength light. Simultaneously with the diffracted waves from these three-dimensional picture elements, reference beams 93 ₁ , 93 ₂ , 93 ₃ that interfere with these diffracted waves are incident on the holographic photographing sensitive material 89 to photograph elemental holograms related to the three-dimensional image. . In order to record three color information, one aperture is used instead of the three apertures mentioned above, and the wavelength of the laser for holographic photography is changed while moving the aperture in a direction perpendicular to the parallax direction of the 3D picture elements, resulting in a sequential exposure method. The same elemental hologram as when using three apertures can also be obtained by using three apertures. For each three-dimensional picture element, a Fournel transform type composite hologram can be obtained by sequentially exposing the aperture to a position corresponding to the viewpoint of the three-dimensional picture element. Each color element hologram 94 ₁ , 94 of the composite hologram 93 obtained in this way
₂ , 94 ₃ respectively corresponding wavelength light 95 ₁ ,
95 ₂ , 95 ₃ or by placing a color filter 99 ₁ , 99 ₂ , 99 ₃ in front of each color element hologram that allows only one wavelength light to pass through and illuminating them with three color lights. The reproduced image 96 can be obtained as a real image. Therefore, a second holographic photographing sensitive material 97 is placed on this real image reproduction surface, and reference beams 98 ₁ , 98 2 , 98 ₂ , etc. having an incident angle such that the direction cosine of the reproduced stereoscopic picture element image in the parallax direction is approximately zero. ₉₈₃ is made incident on a sensitive material for holographic photography to produce an imaging type composite hologram. From the hologram obtained in this way, the information of a plurality of three-dimensional picture elements is separated in space, arranged in the parallax direction of the three-dimensional picture elements, and reproduced, as in the previous embodiment. Further, in the arrangement plane, the color information light beams of the three-dimensional picture elements are separated in the vertical direction of the parallax, and their spread in that direction is restricted.
Therefore, similarly to the color stereoscopic display method using three apertures shown in FIG. 18, a color stereoscopic display can be produced by placing interference filters in the three apertures and illuminating the hologram with white light. The specific optical arrangement is shown in FIG.

The light emitted from the white light source 100 is focused onto the pinhole 102 by the condenser lens 101, and the light transmitted through this is converted into parallel light, diverging or converging light by the lens 103, and the resultant light is formed by the arrangement shown in FIG. The image-shaped hologram 104 is illuminated. Three color information lights are separated from this hologram 104 as shown in the figure, and aperture images 105 ₁ , 105
Tie as _{2,105 3} . Color-related crosstalk aperture images are also formed before and after this imaging plane 106, but these are true because the incident direction of the reference light is set so that it does not have the direction cosine of the parallax direction when creating this hologram. Aperture images 105 ₁ , 105 ₂ , 10
₅₃ in the direction perpendicular to the parallax direction, and the amount of the deviation is determined by the hologram carrier. Therefore, by appropriately selecting the carrier and the aperture size, color-related crosstalk noise can be separated from the true aperture images 105 ₁ , 105 ₂ , 105 ₃ at the aperture image plane 106, and the true aperture image 105
Openings 107 ₁ at positions ₁ , 105 ₂ , 105 ₃ ,
By providing 107 ₂ and 107 ₃ , crosstalk noise can be removed.

In addition, by installing interference filters 108 ₁ , 108 ₂ , 108 ₃ and density filters 109 ₁ , 109 ₂ , 109 ₃ in these three openings, the three necessary quasi-monochromatic lights from the white light can be divided into appropriate amounts of light. It can be obtained by ratio. This aperture image plane 106 is also a plane on which information of each three-dimensional picture element is separated and imaged. An imaging lens 107 is placed close to this aperture image plane 106, and this lens projects a stereoscopic pixel image occurring on or near the imaging hologram 104 onto the stereoscopic screen 110. Aperture image 107 ₁ ,1
By viewing the stereoscopic screen 110 from the real image planes 111 of 07 ₂ and 107 ₃ , color stereoscopic viewing is possible. In this case, the stereoscopic screen 110
not only expands the observable direction in the vertical direction of parallax, but also expands the three-aperture images 105 ₁ , 105 ₂ ,
It also has the effect of mixing three color information of _105.3 . Although this example relates to an imaging type hologram using three apertures, the method for obtaining the hologram of the present invention from a Fresnel type hologram is not limited to this example, and can also be carried out with a single aperture. It can also be carried out elsewhere.

The three-dimensional picture element having color information of the present invention is not limited to a three-dimensional picture element made of a color positive film, but a black and white positive film separated into three colors may be used to record three color information in a hologram.
Furthermore, the present invention is not limited to three-color light, and the present invention can generally be implemented using a plurality of color information.

As is clear from the above description, the present invention relates to a method for producing a color three-dimensional display from a composite hologram made from a plurality of three-dimensional picture elements having color information. The 3D information from the picture elements is separated in space and arranged in the direction where parallax exists, and the parallax direction is also limited to a small vertical direction, and the crosstalk light flux related to color is shifted in the direction perpendicular to the parallax direction to create a hologram. The hologram is illuminated with light of multiple wavelengths, an aperture is placed at a position where the reproduced light beam converges in the direction perpendicular to the parallax direction, crosstalk light flux related to color is removed, and each 3D pixel information is separated and arranged. Color stereoscopic image observation is performed by viewing the stereoscopic pixel image reproduced from the hologram from the plane or its conjugate plane. Therefore, the present invention can be implemented using any hologram production method or reproduction method that satisfies this requirement.

[Brief explanation of the drawing]

Figure 1 is a diagram showing a method for creating picture elements for creating a composite hologram, and Figure 2 is a diagram showing a method for creating a conventional composite hologram using the picture elements created by the method shown in Figure 1. , FIG. 3 is a diagram showing a method of creating a composite hologram used in the method of reproducing a composite hologram of the present invention, FIG. 4 is a diagram showing a method of reproducing a hologram created by the method of FIG. 3, and FIG. FIG. 6 is a diagram showing a method for adjusting color balance, FIG. 6 is a diagram showing a color separation method when using a polychromatic oscillation laser tube, and FIG. 7 is a diagram showing the separation plane of FIG. 4. 8 and 9 are diagrams showing a lens for expanding the visual field range, and FIGS. 10 to 14 show a recording method with a different arrangement from that of the recording method shown in FIG. 3. Figure 15 shows
A diagram showing the case where the reproduction method of the present invention is implemented as an imaging hologram, FIG. 16 is a diagram showing the reproduction method,
FIG. 17 is a diagram showing the recording method, FIG. 18 is a diagram showing the reproducing method, FIGS. 19 and 20 are diagrams showing the recording method, and FIG. 21 is a diagram showing the reproducing method.

Claims (1)

[Scope of Claims] 1. A method of forming a hologram by making a plurality of sets of object light and reference light carrying different color information incident on a hologram recording medium and recording the formed interference fringes. , a first object light and a first reference light that have passed through a predetermined aperture are incident on the hologram recording body, and a second object light and a second reference light that have passed through a predetermined aperture are incident on the hologram recording body. When the hologram recording medium is illuminated with light having a plurality of wavelength components and reproduced, a first object beam formed by a hologram formed by the first object beam and the first reference beam An aperture image of one display wavelength is formed at a predetermined position, and an aperture image of a second display wavelength formed by the hologram formed by the second object beam and the second reference beam is approximately at the predetermined position. A hologram creation method characterized by creating a hologram so that the images are formed at the same position.