JPH0470638B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a hologram production apparatus for producing a white light reproduction type cylindrical holographic stereogram using a combination optical system of cylindrical lenses.

<Prior art> Currently, when producing a white light reproduction cylindrical holographic stereogram, as shown in FIG. I've started taking pictures from off the road, changing the angle little by little. At this time, the object 1 may be placed on the rotation stage 3 and rotated. One frame of the photographed film is recorded as an elongated slit-shaped Fournel hologram by the optical system shown in b. Photographing a hologram using this optical system will be explained. Laser light from a laser light source not shown is
It is divided into two by a spectrometer (not shown).

One of the laser beams passes through the lens 4 and the original image 5 on the film, and then is photographed by the lens 6, forming a projected image of the original image at the position of the large-diameter field lens 7. Thereafter, the light is focused by the large-diameter field lens 7 and the large-diameter cylindrical lens 8 at the position 12 in the vertical direction, and at the slit 9 in the horizontal direction. The light reaches the film 10 as the object light of the hologram.

The other laser beam is expanded by a lens 11, passes through a slit 9 from diagonally above, and is recorded as a hologram on a film 10 as a hologram reference beam.

When the recorded hologram is illuminated with white light from the angle of the reference light, the original projected image can be observed from near the position 12 based on the rainbow hologram principle. With this optical system, the film 10 is moved in parallel by the width of the slit for each frame, exposed repeatedly, and then developed and formed into a cylindrical shape.
When this hologram 13 is illuminated at step 4, a three-dimensional image is observed inside the cylinder as shown at c. To explain the roles of the two large aperture lenses used here,
The field lens 7 is used to widen the viewing area in the vertical direction, and the cylindrical lens 8 is used to expand the viewing area in the horizontal direction and to condense light onto the slit 9.

It is extremely difficult to make such large field lenses and cylindrical lenses. Therefore,
Multiplex has created cylindrical lenses by filling liquid between plastic sheets, but they are not very accurate and are limited in size. Also,
Eidetic has a large diameter cylindrical lens 8.
However, in this case as well, there is a limit to the size that can be manufactured due to the use of a large aperture lens. Furthermore, although a device using a hologram lens and a device using a cylindrical surface mirror have been proposed, the vertical component is not taken into consideration in these two devices.

<Problems to be Solved by the Invention> The present invention has been made in response to the above-mentioned current situation, and uses a commonly used small optical component instead of a large-diameter lens, and also controls the optical component vertically and horizontally. By providing the device, a general hologram production device that is miniaturized is provided.

<Means and actions for solving problems> The present invention will be explained in detail below with reference to the drawings.

FIG. 1a is an explanatory cross-sectional diagram of the apparatus of the present invention seen from the side, and FIG. 1b is an explanatory diagram of the cross-sectional view seen from above. Referring to the figure, the shutter 21 opens and closes the laser beam, the mirrors 22, 24, 25, 26, and 29 each reflect the laser beam at a certain angle, and the half mirror 23
splits a laser beam in one direction into two directions.

In order to adjust the laser beam to a horizontal beam and obtain a laser beam that spreads laterally,
A lens system 30 consisting of a combination of several types of lenses is provided. The original film 32 is a film in which an object is photographed from multiple angles.
A hologram 9 is recorded by interference of two laser beams.

Next, specific operations will be explained.

Light emitted from a laser (not shown here) passes through a shutter 21, is reflected by a mirror 22, and is split into two by a beam splitter 23.
The light passing through the beam splitter 23 is sent to the mirror 2
After being reflected at 9, the light passes through a lens system 30 and a lens 31, and becomes elongated light in the horizontal direction. After passing through the original film 32, this light is magnified by a cylindrical lens 33 that has power only in the vertical direction.
It is focused by cylindrical lenses 34 and 35, reflected by a plane mirror 36, reflected by a plane half mirror 37, reflected by a cylindrical concave mirror 38 that has power only in the lateral direction, and passed through the half mirror 37.
It passes through the slit 41 and reaches the film 39.

At this time, in the vertical direction, after passing through the transparent original film 32, the image is projected by the cylindrical lens 33, and the cylindrical lenses 34, 35
The light is converged and concentrated at a point 40.

On the other hand, for the horizontal direction, transparent original film 3
2, by a cylindrical concave mirror 38,
The light is focused at the position of the slit 41 on the film 39. Although it is not used as an imaging system, the original film 32 is illuminated with parallel light, and there is almost no effect of scattering or diffraction on the film 32, so this light is focused on the cylindrical lens 34 after it is imaged. , it has the same shape as the light converging on the slit 41 on the film 39.

This light thus reaches the film 39 in the same manner as the object light of the prior art. The light reflected by one half mirror 23 passes through mirrors 24, 25, and 26, and then passes through the lens 2.
Aperture 2 widened and movable by 7
After passing through 8, the film 39 is reached. These two beams are adjusted so that their irradiation positions coincide with each other, forming interference fringes on the film 39, and the film records the interference fringes. After one recording is completed, the part indicated by the dotted line moves upward or downward as indicated by the arrow to illuminate a new part of the original image,
Different parts of the film 39 are exposed. The amount of movement at this time, that is, the ratio of division, is set so that there is no flicker when the manufactured hologram is reproduced. Through this series of operations, the original film is scanned from top to bottom to create a slit-shaped hologram on the film 39 from one original frame. At this time, the mirror 3
6 moves in the direction shown by the arrow with respect to the lens 35, and the half mirror 37 rotates about the horizontal direction. Although the system for moving is not shown here,
Each movement is performed using the rotation of a step motor controlled by a computer.

Note that in this system, by changing the lenses 33 and 34, an arbitrary magnification can be selected.

The operation of the present invention will be explained in more detail.

As shown in FIG. 3, the laser beam that has passed through the convex lens 31 and spreads laterally first passes through a portion of the original film corresponding to one frame, as indicated by a. Next, while the laser beam is temporarily blocked by the shutter 21, the lens stand indicated by the dotted line in FIG. 1 moves downward under the action of the lens vertical movement device 50. Then, the laser beam hits the original film 32 in Figure 3.
When reaching the position where part b of one frame is to be irradiated, the movement of the lens vertical moving device 50 is stopped, and then the shutter 21 is opened, and the part b of the original film is irradiated with the laser beam. At this time, as the lens base moves downward, the focal position shifts, so the rotating mirror 37 rotates under the action of the lens rotation device 60, and returns to the same focal position as before.
It is set to 0.

In this way, a of 321 frames of original film
The laser beam irradiation is performed on each of the sections .about.J, and interference fringes are formed on the film 39, which are recorded.

Next, the film 39 is moved laterally and the same operation is repeated until the next frame A' to J' of the original picture 32 is reached. The above operation is repeated for each frame of the original image.

At this time, the opening and closing of the shutter 21, the vertical movement of the lens stand 45, and the rotation of the rotary mirror are controlled by control signals from the system controller 80, in which necessary operation programs are stored in advance. , the shutter opening/closing device 70, the lens vertical movement device 50, and the lens rotation device 60.

In addition, instead of providing such a lens vertical movement device to move the lens vertically, it is possible to move the original film 3.
2, and the film 39 is moved up and down, the result is the same, but in this case the weight of the film 39 becomes considerably large, so it is better to move the lens up and down in terms of energy efficiency.

Although the present invention has been explained using a system using a simple laser, this requires a large amount of time considering the influence of vibration due to movement, so it is considered optimal to use a pulsed laser with a short oscillation period.

Further, although a system using a concave mirror in the horizontal direction has been shown, the same effect can be achieved using a cylindrical lens.

<Effects of the Invention> The present invention is as described above, and produces the following excellent effects.

In other words, by installing a vertical movement device for the lens and a rotation device for a rotating mirror, and by scanning one frame of the original film up and down with a laser beam, the lens can be made smaller and can be made with a large aperture, which had previously been difficult to manufacture. There is no need to use a lens, and the device can be simplified.

[Brief explanation of the drawing]

FIG. 1 is an explanatory cross-sectional view of the apparatus showing the entire invention, in which a is an explanatory view seen from the side, b is an explanatory cross-sectional view seen from above, and FIG. 2 a is an explanatory view showing the photographing position of an object. FIG. 3B is an explanatory diagram of a conventional holographic stereogram production apparatus, FIG. 3C is an explanatory diagram showing the principle of a completed holographic stereogram, and FIG. 3 is an explanatory diagram of an original film. 1...object, 2...camera, 3...rotation stage,
4, 6, 10, 11, 27... Lens, 7... Large diameter field lens, 8... Large diameter cylindrical lens,
9,41...Slit, 12,40...Point, 13...Hologram, 14...White light source, 21...Shutter,
22, 24, 25, 26, 29...mirror, 23...
Half mirror, 28...Movement, 30...Lens system, 3
1...Convex lens, 32...Original film, 33,3
4, 35... Cylindrical lens, 36... Mirror, 37... Mirror, 38... Cylindrical concave mirror or cylindrical parabolic mirror, 45... Lens stand, 50... Lens vertical movement device, 60... Lens rotation device, 70... Shutter opening/closing device, 80... System control device.

Claims (1)

[Claims] 1 A laser beam is split into two by a beam splitter, one of which is passed through an original film in which an object and its movement are photographed from multiple angles, and then these two laser beams are made to interfere, In an apparatus for producing a cylindrical holographic stereogram by exposing the interference fringes onto a film, there is provided a shutter opening/closing means for blocking laser light, and a lens stand equipped with a mirror, a convex lens, a cylindrical lens, etc. A means for moving the lens stand up and down and a means for rotating a rotating mirror for adjusting the focus position are provided to change the irradiation position of the laser beam relative to the original film and the film. A cylindrical holographic stereogram production device that creates a holographic stereo on a film by scanning the original film vertically with a laser beam in the form of a plurality of divided frames.