JPH0664411B2 - Method for producing full color disc hologram - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a technique for producing a disk hologram by using a ring-type stereogram as a master hologram, and in particular, a series of color photographs with parallax is colored. When three ring-shaped stereograms were combined from the original images corresponding to the red, green, and blue components created by decomposition, and the resulting three stereograms were used as master holograms, when the disk hologram was reproduced with white light. The present invention relates to a technique for producing a disk-type image hologram at a position where reproduction is performed in red, green, and blue at a predetermined position, and a technique for reproducing an image of the disk hologram in full color.

<Prior Art> An example of a method for producing a disk hologram is shown below.

First, the original picture is prepared. As shown in FIG. 2, an object 1 is placed on a turntable 3 and is rotated at a constant speed, and a cine camera 2 directed downward is used to shoot an image from a lick above the object which is inclined by θ. In this way, a photograph of the subject viewed from the position rotated by the constant angle a is obtained.

Next, a stereogram is synthesized by using this series of photographs as original images. The optical system used is as shown in FIG.
A brief description of the system is given. The laser light emitted from the laser light source 4 is split into two lights by the beam splitter 5. After one is reflected by the mirror 6, it spreads through the objective lens 9 and the pinhole 11 and passes through the condenser lens 13 to form an image on the screen 17. The light from the screen passes through the slit 18 and hits the dry plate 19. The other light is reflected by the mirror 7, the objective lens 10, the pinhole 12
After passing through, the collimator 14 collimates the light to form parallel light, which is reflected by the mirror 8 and passes through the slit 18 to vertically enter the dry plate as reference light. Further, with this thread, the dry plate 19 is separated from the screen 17 by d, and has a rotation axis directly in front of the center of the turntable image projected on the screen. The position of the slit 18 is θ from the image of the turntable.
The angle is inclined.

The synthesis procedure will be described. The first original image is placed at 16 positions of this optical system, and the first image reflected on the screen is recorded as a hollow-shaped hologram on the dry plate 19. Next, in place of the second original image, the dry plate is rotated by a constant angle a, and a hologram is recorded in the same manner. Similarly, holograms are recorded one after another, and a stereogram in which ring-shaped holograms are arranged in a ring shape is created.

A disk hologram is created by using this stereo glass as a master hologram. As shown in FIG. 4, the ring-shaped hologram 19 is d with respect to the disk-shaped dry plate 21.
Set it at a position that is far away. The hologram 19 and the dry plate 21 are proved by shining a laser beam parallel to the dry plate vertically. The reproduced image of the hologram 19 is formed on the dry plate 21, and the image hologram is recorded by the interference with the parallel light directly reaching the dry plate 21. As shown in FIG. 5A, when this hologram is illuminated with white light from directly below, a stereoscopic image is seen from the position where the tilt-up ring type master was.

Further, when the photoresist is vapor-deposited as a dry plate or a reflector is placed under the dry plate, as shown in FIG. 5B, it is possible to illuminate from directly above and see a stereoscopic image from above. it can. In this way, a disc hologram is created.

<Problems to be Solved by the Invention> The disc hologram produced by the conventional technique changes its color by moving the viewpoint up and down like a rainbow hologram, but the color of the image seen at that time is generally the same. The colors are the same, and it is not possible to express the difference in color depending on the part. Also, the visible colors are limited to the primary colors of red to purple, and it is not possible to express intermediate colors such as a dark color and pink. Therefore, the color of the actual subject cannot be expressed as a hologram.

<Means and Actions for Solving Problems> Generally, when holograms are reproduced at different wavelengths, images are reproduced at different positions. In FIG. 6, when a hologram is recorded on the dry plate 25 by the light from the point O1 and the parallel light, the wavelength λ2 at the time of recording, the distance d1 between the object O1 and the dry plate 25,
When ψ is not so large as the distance d2 between the reproduced image O2 and the dry plate 25, the relationship of d2 / d1 = λ1 / λ2 is established. Therefore, when the hologram is reproduced with white light, the color (wavelength) of the image reproduced at a certain position can be determined by the positional relationship between the dry plate and the object at the time of recording. When this is applied to a disk hologram, the color of the image when viewed from a certain position during white light reproduction can be determined by setting the distance between the ring-type master hologram and the dry plate to an appropriate value during hologram production. In particular, if a master hologram is placed at a position where red, green, and blue are visible at a certain position when reproducing white light to form a hologram, an image of an arbitrary color can be represented by a combination of the brightness of each image. The present invention utilizes this fact, and the original image is separated into three colors of red, green, and blue, and three images for each image are obtained.
By making two length-type holograms and recording the holograms at the positions where red, green, and blue are reproduced at a certain point, the images of the respective colors will match when viewed at that point during the reproduction. It is visible and represents the original color.

Next, description will be made along the manufacturing procedure.

First, the original picture is prepared. First, as in the conventional case, as shown in FIG. 2, a series of photographs having a parallax in the lateral direction of the subject 1 is taken. However, the film used at this time must be a color film. A series of color photographs obtained in this way are separated into red, green, and blue components using a scanner, and a positive film of an image corresponding to each color is made. A continuous photograph of these positives is used as the original picture.

A series of red, green and blue stereograms obtained as described above is synthesized. The system used is the one used in the past (3rd
The position of the dry plate and the slit are different from the conventional ones, but they are placed at three positions corresponding to red, green and blue as shown in FIG. Distance d from the dry plates 26, 27, 28 corresponding to red, green and blue to the screen 17 in FIG.
R, dG, and dB are the shooting wavelengths with respect to the distance d from the position where the dry plate 19 was located in the prior art to the screen 17,
If the wavelengths of red, green, and blue are λR, λG, and λB, dR / d =
There is a relationship of λR / λ, dG / d = λG / λ, dB / d = λB / λ.

Further, the slits 29, 30, 31 corresponding to red, green, and blue are located around a straight line which passes through the position where the slit 18 was formed in the conventional technique and is vertical to the screen. However, the slits 29, 30, 31 are located at slightly different positions from each other so that the laser beams illuminating the red, green, and blue stereograms do not overlap when the image holograms are combined later.

In this system, first, a positive film corresponding to a red component is used as an original image film, and a ring-shaped stereogram is synthesized in the same manner as in the conventional method at positions 26 and 29 corresponding to red for a dry plate and a slit. Next, for blue and green, similarly, the original images of blue and green are used, respectively, and ring type stereograms are synthesized at the positions of the blue and green plates and the slits. In this way, three stereograms that are masters of the disc hologram are produced.

Using these three stereograms as masters, a disk hologram is synthesized using a system as shown in FIG. In FIG. 7, the three stereograms 26, 27 and 28 are located at the same distance from the disk type dry plate 32 as the distances dR, dG and dB from the screen when synthesized. In this optical system, the parallel laser light is vertically applied to the stereograms 26, 27, 28 and the dry plate 32, and the three masters 2
An image hologram is created between the reproduced images from 6, 27 and 28 and the parallel light that has reached the dry plate. The hologram thus constructed tilts up when white light is applied from directly below, and when it is bent from the line perpendicular to the hologram by θ, red,
A full-color reproduced image can be observed by combining the reproduced images of green and blue.

<Example> A cine camera is used to shoot an object on a color film at an angle of about 15 ° from right above, and color separation into red, green, and blue components is performed using a color scanner used for printing plate making. I went.

Using them as original images, using the Agfa 8E56HD as a dry plate for the master hologram, Ar laser 48
The picture was taken at 8mm. For development, GP61 was used and development was carried out at 20 ° C. for 3 minutes. The position of the dry plate for each color is about
Considering that 30 cm would be seen from a bare spot, the positions were 38 cm, 33 cm, and 28 cm from the screen with respect to red, green, and blue, respectively.

As a sensitive material for the disk hologram, Az1350 photoresist manufactured by Shipley Far East Co., Ltd. was used. Az303A developer was diluted 1: 5 and developed at 20 ° C. for 40 seconds.

When aluminum was vapor-deposited on the hologram thus formed and white light was applied from above, a reproduced image of almost the same color as the actual color could be obtained from diagonally above.

<Effects of the Invention> According to the present invention, it is possible to represent the color of a subject with a disk hologram, and it is industrially effective in expressing the hologram display.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory view showing a part of a master hologram photographing system in the present invention, FIG. 2 is an explanatory view showing an original image photographing system, and FIG. 3 is a ring type. FIG. 4 is an explanatory view showing a stereogram synthesizing system, FIG. 4 is an explanatory view showing a disc hologram imaging system, FIG. 5 is an explanatory diagram when observing a reproduced image of the disc hologram, and FIG. 6 is different holograms. FIG. 7 is an explanatory view showing a reproduction position when reproducing at different wavelengths, and FIG. 7 is an explanatory view showing an imaging system of a disk hologram according to the present invention. 1 …… Subject 2 …… Turntable 3 …… Cine camera 4 …… Laser light source 5 …… Beam splitter 6 …… Mirror 7 …… 〃8 …… 〃9 …… Objective lens 10 …… 〃11 …… Pinhole 12 …… 〃 13 …… Condenser lens 14 …… Collimator 15 …… Projection lens 16 …… Original film 17 …… Screen 18 …… Slit 19 …… Dry plate 20 …… Dry plate rotation axis 21 …… Dry plate 22 …… Objective Lens 23 …… Pinhole 24 …… Collimator 25 …… Dry plate 26 …… 〃 27 …… 〃 28 …… 〃 29 …… Slit 30 …… 〃 31 …… 〃 32 …… Dry plate

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References Optical Technology Contact Vol. 19, No. 4, PP. 12-22 Toshio Numakura Ed. Electronic Engineering Progress Series 6 "Holography" (Sho 49-11-5) PP. 61-66

Claims (1)

[Claims] 1. A series of color photographs having a parallax in the lateral direction is obtained by placing a subject on a turntable and taking a picture from above the lick while rotating it. The series of color photographs obtained are red, green and blue. A positive film original was obtained by decomposing into three color components, and three ring-type stereograms were synthesized using the obtained positive film original to obtain 3
A method for producing a full-color disc hologram, in which three stereograms are arranged as master holograms at specific positions to photograph a disc-shaped image hologram.