JPS6019514B2 - 3D image recording and playback method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a three-dimensional image recording and reproducing method that applies holography technology to record on a recording medium and reproduces it as a three-dimensional image.

In general, the object to be recorded is recorded as a hologram by irradiating the same area of a recording medium such as a photographic plate with an object beam from the object to be recorded and a recording reference beam from a light source that are far apart from each other. It is known that a recorded object can be reproduced as a three-dimensional image by irradiating only reproduction reference light in the same direction as the recording reference light.

FIG. 1 is an explanatory diagram of the optical path during reproduction in the conventional three-dimensional image recording and reproduction method. When the reproduction reference beam 7 is irradiated onto the hologram 11 at an incident angle of OR, the 0th-order diffracted beam 8 is almost an extension of the reproduction reference beam 7. This is limited by the range 1 in which the observer 6 can observe the stereoscopic image 41, the angle of view 8' with respect to the hologram 11, or the 0th-order diffracted light 8.

In such conventional stereoscopic image recording and reproducing methods, it is possible to bring the recorded object as close as possible to the recording medium during recording, but if the incident angle OR of the reproduction reference beam 7 is increased, the resolving power of the recording medium will cause hologram diffraction. This has the disadvantage that the effect is lowered and furthermore, there is a portion where the optical path difference between the recording reference beam and the zero-object beam becomes large, which is disadvantageous to the coherence conditions and the hologram becomes unclear.

Furthermore, when the object to be recorded is brought close to the recording medium during recording, the recording reference light is blocked by the object to be recorded, so that uniform hologram recording cannot be achieved. The present invention was made in order to eliminate the above-mentioned drawbacks, and it is an object of the present invention to provide a stereoscopic image recording and reproducing method that can record and reproduce large stereoscopic images brightly and with good quality.

0 This invention will be explained below according to examples. FIG. 2 shows a schematic configuration example of an optical system for recording a recording medium according to the method according to the present invention. In this figure, 1 is a recording medium such as a photographic plate, 21 and 22 are light sources for recording, and 31 and 32 are light sources for recording.
Recording reference light from 22, 4 a recording object to be recorded,
Reference numeral 5 denotes object light from the recording object 4. The object light 5 is obtained by, for example, reflecting a part of the recording reference beams 31, 32 on the recording object 4. The object beam 5 and the recording reference beams 31, 3
2 is Wataru Kachi.

In the configuration shown in this figure, the recording reference beams 31 and 32 are set to irradiate different areas of the recording medium 1 from two different directions, and the recording reference beams 31 and 32 are incident on the recording medium 1. The object beam 5 is recorded as a hologram in different areas of the recording medium 1. Here, the recording reference beams 31 and 32 incident on the recording medium 1
This will be explained in more detail with reference to FIG. In FIG. 3, the recording reference beams 31 and 32 are set at relatively small incident angles so that they do not cross in front of the recording medium 1 (the front side is the side where the object 4 or image exists with respect to the recording medium 11). Then, each predetermined partial area of the recording medium 1 is irradiated.

At this time, the recording reference beams 31 and 32 enter the recording medium 1 in different directions and illuminate different partial areas on the recording medium 1, respectively. Note that the recording reference light 31,
The boundary of the area irradiated by 32 is not required to be more precise than the characteristics of the hologram, and even if there is some overlap or space, it will have little effect on the reproduced stereoscopic image. FIG. 4 shows a schematic configuration example of an optical system for reproducing a recorded object from a recording medium in which the recorded object is recorded as a hologram according to the method according to the present invention.

In this figure, reference numeral 11 denotes a recording medium in which the recorded object 4 is recorded as a hologram by recording reference beams 31 and 32 that irradiate different partial areas from two different directions, respectively;
Reference numerals 91 and 92 are light sources for reproduction, 71 and 72 are light sources for reproduction, reproduction reference beams from 91 and 92, 41 is a three-dimensional image of the reproduced recorded object, and 6 is an observation point. As shown in this figure, reproduction light sources 91 and 92 are arranged on the recording medium 11 in the same way as the recording light sources 21 and 22 during recording, and reproduction reference beams 71 and 72 are irradiated onto the recording medium 11 for observation. Point 6
When observed from above, the entire stereoscopic image 41 can be seen.
This three-dimensional image 41, as shown in FIGS. 5 and 6,
A virtual image and a real image are observed depending on the case where a reproduced reference beam with the same wavefront is used and the case where a reproduced reference beam with a conjugate wavefront is used, respectively. It goes without saying that the reproduction reference beam does not have to be flexible, and the boundaries of the areas on the recording medium to which the recording and reproduction reference beams are irradiated are not required to be very strict. In addition, in the above embodiment, the case where there are two recording reference beams and two reproduction reference beams is shown, but the number of each reference beam may be larger, and the direction of incidence is also limited to this embodiment. isn't it. As described above, in the stereoscopic image recording and reproducing method according to the present invention, the object light from the recording medium is irradiated onto the recording medium, and at the same time, the object light is irradiated.
By irradiating the recording medium with a plurality of recording reference beams from different directions, each of which irradiates a different partial area of the recording medium, such that the recording reference beams do not intersect on the recording medium side of the recording medium. , the recorded object is recorded as a hologram on the recording medium, and then a plurality of partial areas of the recording medium to be reproduced are different from each other from the same direction as the plurality of recording reference beams. Since the recorded object is reproduced as a three-dimensional image by irradiating a plurality of reproduction reference beams that emit a , high diffraction efficiency and uniform hologram recording. Furthermore, since the three-dimensional image is reproduced using a plurality of reproduction reference beams, a plurality of reproduction light sources can be used simultaneously, and reproduction of a brighter three-dimensional image can be easily realized.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of an optical path during reproduction in a conventional stereoscopic image recording and reproduction method, FIG. 2 is a schematic diagram showing an example of the configuration of an optical system during recording according to the present invention, and FIG. Explanatory diagram showing the positional relationship between the recording reference beam and the recording medium in the figure, No. 4
The figure is a schematic diagram showing an example of the configuration of an optical system during reproduction according to the present invention, and FIGS. 5 and 6 are explanatory diagrams showing the positional relationship between the reproduction reference beam and the silver medium in FIG. 4. . In the figure, 1 and 11 are recording media, 21 and 22 are recording light sources, 31 and 32 are recording reference beams, 4 is a recorded object, 41 is a stereoscopic image, 5 is an object beam, 6 is an observation point, and 71 and 72 are Reproduction reference beams 8, 81, and 82 are zero-order 0-diffracted beams, and 91 and 92 are reproduction light sources. Note that the same reference numerals in the figures indicate the same or corresponding parts. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] 1. Irradiate the recording medium with object light from the recording object, and at the same time as irradiate the object light, a plurality of recording reference beams from different directions, each of which illuminates a different partial area of the recording medium, are applied to these recording reference beams. The recorded object is recorded on the recording medium as a hologram by irradiating the recording medium so that the light does not intersect on the recorded object side of the recording medium, and then a plurality of holograms are recorded on the recorded recording medium. The recorded object is reproduced as a three-dimensional image by irradiating a plurality of reproduction reference beams from the same direction as the recording reference beam, each of which irradiates a different partial area of the area to be reproduced of the recording medium. A three-dimensional image record green reproduction method.