JPH0664410B2 - Full-color rainbow hologram and its manufacturing method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a technique for producing a rainbow hologram by using a flat holographic stereogram as a master hologram, and reproduces a rainbow hologram image in full color. It is about the technology to make.

(Prior Art) An example of a method for producing a rainbow hologram using a flat holographic stereogram will be described below.

First, an original image is prepared. When making a hologram from a real subject, a system as shown in FIG. 4 is used. The camera (2) is moved in the horizontal direction at regular intervals α, and the subject (1) is photographed each time. In this way, a series of photographs of images of the subject (1) viewed from different positions, that is, images of the subject (1) having a parallax in the horizontal direction can be obtained. This is the original image of the flat holographic stereogram. In the case of using computer graphics as the original image, a system having a horizontal parallax, which is obtained when an actual subject is present, is output as computer graphics, and this series of photographs is used as the original image.

Next, a flat type holographic stereogram is synthesized from this original image. An optical system as shown in FIG. 5 is used for the synthesis. A laser beam emitted from a laser light source (3) is split into two beams by a beam splitter (4), one beam is reflected by a mirror (16) and then focused on a pinhole (6) by an objective lens (5). Tied and spread
An image of the original image (8) is formed on the screen (10) by the projection lens (7 ') while passing through the original image (8) while being condensed by the condenser lens (7). Then, the other light from the screen (10) to the photographic plate (12) through the vertically long slit on the mask (11),
After being reflected by the mirrors (17) and (18), focused by the objective lens (13), focused by the pinhole (14), it spreads and becomes parallel light by the collimator lens (15), and then the mask (11 ) Through the slit to the photo plate (12). With this optical system, set the first frame of the original image at the position of the original image (8), perform exposure, and place the screen (1
A hologram of the image of the original image (8) shown in (0) is prepared. The original image is changed to the next frame, and the dry plate is moved laterally by the slit width to create a hologram corresponding to the next image on the dry plate. By repeating the same operation, a hologram in which images having different parallaxes are recorded is arranged in a line on the dry plate (12). In this way, the flat holographic stereogram is synthesized.

Next, using this plane type holographic stereogram as a master hologram, a rainbow hologram is produced by an optical system of a general rainbow hologram as shown in FIG. In this system, the laser beam emitted from the laser light source (19) is split into two by the beam splitter (20), one of which is reflected by the mirror (21) and the lens (27).
After being spread by the lens, it becomes parallel light at Lens (30) and illuminates the dry plate (12) recording the hologram, and a part of it passes through the slit on (21) as the object light and becomes a photo dry plate. The image is formed at (22), and the other is passed through mirrors (25) and (21) to be expanded by the objective lens (23) and passed through a pinhole (24) to serve as reference light on a photographic plate ( 22).

When the recorded rainbow hologram is illuminated from the opposite direction of the reference light, a stereoscopic image can be seen at the slit position on the slit (21). The color of the image at this time is the same as the color of the light used for recording. Also, by moving the viewpoint up and down, the color of the image changes to a rainbow color from red to purple. However, the entire image is the same color, and there is no difference in color depending on the location.

(Problems to be Solved by the Invention) A hologram produced by a conventional method has the same color as a whole, and thus it is impossible to express a difference in color depending on a place. In addition, it is not possible to represent intermediate colors such as a dark color and a pink color. For this reason, the color of the subject cannot be represented on the hologram.

(Means for Solving Problems) The present invention has been made in view of the above-mentioned present situation, and it is possible to capture an image while moving a camera or to display a parallax created by computer graphics. Three flat holographic stereograms, which were synthesized by using a positive film obtained by separating a series of color images into red, green, and blue components as the original images, were used as master holograms, and these were placed at specific positions. In the above, there is provided a full-color rainbow hologram that allows a full-color image to be seen when viewed from a predetermined position by photographing a rainbow hologram, and a method for manufacturing the same.

(Operation) When the rainbow hologram is reproduced with white light, the slit image is reproduced at different positions as shown in FIG. 1 depending on the wavelength of the light. At this time, the wavelength λ used for hologram recording, the reference light λ, the angle θ ₁ formed by the reference light and the object light, and the wavelength λ ₂ of the light during reproduction, the angle θ formed by the illumination light and the reproduction light
_{Between two} , The relationship is established. From this, if the viewing position is determined, the color of the reproduced image can be determined by adjusting the angle formed by the object light and the reference light instead of the position of the master hologram at the time of shooting. On the other hand, the colors are red, green and blue.
Since it can be separated into colors, when creating a rainbow hologram a master hologram on which images corresponding to the red, green, and blue components of the subject were recorded, when the rainbow hologram was reproduced with white light, in front of the hologram, ,
When a rainbow hologram was photographed at a position where the reproduced image could be seen in red, green, and blue, when reproduced, in the front of the hologram, a red image corresponding to the red component, a green image corresponding to green, and a blue image were corresponded. The blue images will overlap and you will see a full-color image. However, as shown in FIG. 1, the spectrum of the slit image is formed with an inclination with respect to the hologram, so that the master hologram needs to be inclined at an appropriate angle with respect to the rainbow hologram. Otherwise, the slit images of the respective colors are reproduced from the rainbow hologram at different distances, and the images having different parallaxes enter the eyes depending on the colors, causing a color shift. Tilting angle Benton (personal name) A Cromartie poke inclination angle of the angle kept in making holograms of FIG. 3 the master alpha, approximation to the incidence angle Q _R of the reference light formula
given by tan α = SinQ _R. This angle is called the achromatic angle by Benton.

(Example) Hereinafter, the present invention will be specifically described by way of an example with reference to the drawings.

First, the original picture is prepared. First, a series of photographs with a parallax in the lateral direction is obtained from a real object or CG. Although the photographing method at this time is the same as the conventional method, a monochrome film is usually used, whereas a color film is used. Using the color scanner that is used for printing plate making, the continuous color photographs obtained in this way
Color separation is performed on the green and blue components to produce positive continuous photographs corresponding to each image. In this way, red, green,
Get three original pictures corresponding to blue.

Next, three planar stereograms are synthesized from these three original images. The optical system used for the synthesis is almost the same as the conventionally used system (Fig. 5), but as shown in Fig. 2, the point that the photographic plate (35) has an inclination α and the photographic plate (35). The difference is that the overlying mask (36) has three slits 37 (a, b, c).
The inclination angle α of the dry plate is an achromatic angle that can be determined by the angle of the reference light when the rainbow hologram is photographed.
In this optical system, an original image corresponding to red is placed at the position of the original image (39), only the slit (37a) corresponding to the mask-shaped red is opened, and the other slits are closed, and the screen (38) is operated in the same manner as the conventional one. A flat holographic stereogram is synthesized by directing laser light through. Green
Similarly for blue, three plane type holographic stereograms corresponding to red, green and blue are synthesized on one dry plate. However, at this time, the same picture of red, green,
Make sure that the holograms corresponding to the blue component are aligned vertically in the vertical direction. The three planar holographic stereograms thus created are used as master holograms for rainbow holograms.

Next, a rainbow hologram is synthesized from these holograms. The difference between the system used at this time and the system of ordinary rainbow holograms is that, as shown in FIG. 3, the master hologram of the photo plate (35) is inclined by the achromatic angle, and the three master holograms and That is, three corresponding slits (40) are used. As described above, the positions of these slits are determined so that the angles of the object light and the reference light are such that red, green, and blue are reproduced in front of the hologram when reproducing white light.

When the rainbow hologram thus produced is illuminated with white light from the opposite direction of the reference light, a full-color stereoscopic image can be seen at the position where the three slit images overlap each other in front of the hologram.

In this way, in this example, after taking a photograph on a color film using a camera, color separation was performed on the red, green and blue components using a color scanner used for plate making of printing.

These were used as original images, and 8F56HD of Agfa Co. was used as a dry plate for the master hologram, and images were taken with an Ar laser of 488 nm. Use GP61 for development 2
Development was carried out at 0 ° C. for 3 minutes. The inclination angle of the dry plate is 37
It was ゜.

As the sensitizing material for the rainbow hologram, Az1350 photoresist manufactured by Shipley Fyst Co., Ltd. was used, and predetermined development was performed with a dedicated developer. The angle of the reference light is 45 °, red
The angles formed by the object light and the reference light from the green and blue master holograms were 35 °, 40 ° and 45 °, respectively.

From the hologram taken under these conditions, we were able to obtain a reproduced image of almost the same color as the current color.

(Effects of the Invention) The present invention makes it possible to represent the color of a subject with a rainbow hologram, which is industrially effective in expressing the hologram display.

[Brief description of drawings]

FIG. 1 is a diagram showing a position where a slit image is reproduced when a rainbow hologram is reproduced in a white system, and FIG. 2 is a diagram showing a part of a photographing system of a master hologram of the present invention.
FIG. 4 is a diagram showing a part of a rainbow hologram photographing system of the present invention, FIG. 4 is a diagram showing an original image photographing system, and FIG. 5 is a diagram showing a plane type holographic stereogram combining system. Figure 6 shows a rainbow hologram imaging system. (1) …… Subject (2) …… Camera (3), (19) …… Laser light source (4), (20) …… Beam splitter (5), (13), (23) …… Objective lens ( 6), (14), (24) ... pinhole (7) ... condenser lens (8), (39) ... original image (9), (29), (30) ... lens (10), ( 38) …… Screen (11) …… Mask with slit (12), (22), (35), (41) …… Photo dry plate (15) …… Collimeter lens (16), (17), (18), (25), (26), (28) ……
Mirror (21), (37) …… Slit (31) …… White light (32) …… Red slit image (33) …… Green slit image (34) …… Blue slit image (36), (40)… …mask

Claims (2)

[Claims] 1. A full-color rainbow hologram obtained by the following series of steps. (A) A step of shooting a subject while moving a camera or obtaining a series of color images with parallax created by computer graphics. (B) A step of obtaining a positive film in which the color image is separated into red, green, and blue components. (C) When a flat holographic stereogram is obtained by using the positive film as an original image, a dry plate is tilted by a predetermined angle and the original image is opened for each color component while a slit at a corresponding position is opened. A step of obtaining three flat holographic stereograms by sequentially exposing a dry plate to laser light. (D) When a rainbow hologram is photographed using the stereogram as a master hologram, the dry plate is inclined and arranged at a predetermined angle, and the master hologram is sequentially arranged for each color component while opening slits at corresponding positions. The process of obtaining a rainbow hologram by laser exposure on a dry plate. 2. A method for producing a full-color rainbow hologram, which comprises the following steps. (A) A step of shooting a subject while moving a camera or obtaining a series of color images with parallax created by computer graphics. (B) A step of obtaining a positive film in which the color image is separated into red, green, and blue components. (C) When a flat holographic stereogram is obtained by using the positive film as an original image, a dry plate is tilted by a predetermined angle and the original image is opened for each color component while a slit at a corresponding position is opened. A step of obtaining three flat holographic stereograms by sequentially exposing a dry plate to laser light. (D) When a rainbow hologram is photographed using the stereogram as a master hologram, a dry plate is tilted by a predetermined angle and the master hologram is sequentially arranged for each color component while opening slits at corresponding positions. The process of obtaining a rainbow hologram by laser exposure on a dry plate.