JPS5947298B2 - stereoscopic photography device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a stereoscopic photography device.

As shown in FIG. 1, a conventional stereoscopic photographing device includes a photographing lens 1, a lenticular sheet 2 arranged perpendicularly to the optical axis behind the photographing lens, and a photosensitive material 3.
The support member 4 supports the lenticular sheet 2 in close contact with the back surface of the lenticular sheet 2.

In this stereoscopic photography device, the lenticular sheet and the photosensitive material are integrated, and assuming that the relative positions of the lenticular sheet and the photosensitive material do not change between shooting and playback, the lenticular sheet and the photosensitive material are separated from each other during playback. The direction of the emitted light ray is the same as the light ray that entered the lenticular rice at the time of photographing (however, it travels in the opposite direction). Therefore, the light rays emitted from the lenticular sheet during playback are
The light converges at the location where the exit pupil of the photographing lens was located at the time of photographing.
As a result, the exit pupil diameter of the photographic lens is the distance between the eyes (approximately 65 m).
? If the exit pupil diameter is sufficiently large compared to 11), a sufficient stereoscopic field of view can be obtained, but if the exit pupil diameter is smaller than the distance between the eyes, it is difficult to obtain a normal stereoscopic image of the entire lenticular sheet no matter where the eyes are positioned. become unable to see.

Therefore, in order to obtain a sufficient three-dimensional field of view, a patent application filed in 1983 proposed a three-dimensional photographic device in which a field lens 5 (see Fig. 1) is provided in front of a lenticular sheet over substantially the entire lenticular sheet. -26755.

When a field lens is used during photographing, the light flux emitted from the lenticular sheet during reproduction converges at the position of the virtual image formed by the field lens at the exit pupil of the photographing lens. Since this virtual image is larger than the exit pupil of the photographing lens, the stereoscopic viewing area of the reproduced image is widened. However, in the stereoscopic photograph taken by the stereoscopic photographing device of this Japanese Patent Application No. 52-26755, the focal length of the field lens was made the same as the focal length of the photographing lens, so it was difficult to view the stereoscopic photograph stereoscopically. had the disadvantage that you had to be far enough away from the photo.

Such 3D photographs are very effective for interior decorations, displays, etc. that can be viewed from a sufficient distance, but they are not suitable for small objects that can be viewed right in front of your eyes, such as picture postcards. had the disadvantage of not producing a three-dimensional effect. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a stereoscopic photographing device with a field lens that can take a stereoscopic photograph that can be sufficiently viewed from a distance of approximately human clear vision. .

In the stereoscopic photographing device according to the present invention, the focal lengths of the photographic lens and the field lens are Fl and f2, respectively, the diameter of the exit pupil of the photographic lens is D, the distance between the field lens and the lenticular sheet is S, and the exit pupil diameter is D. When the distance between the position of the virtual image and the lenticular sheet is l, and the diameter of the virtual image at the exit pupil is V (hereinafter used throughout this specification), 2 in the formula is approximately the distance of clear vision. This feature is characterized in that Fl, f2, and S are set so that V is larger than the distance between human eyes.

The present invention will be described in detail below with reference to the accompanying drawings. First, with reference to FIG. 2, the relationship between the focal length of the field lens 5 and the viewing zone will be considered.

As is well known, from the lens formula, photographic lens 1
The diameter D of the exit pupil of The following equation holds true between them.

Furthermore, if the position of the photographic lens 1 is set at a position where the light beam from the point at infinity can form an image on the lenticular sheet 2, then the distance k between the exit pupil of the photographic lens 1 and the lenticular plate is given by the following formula. Given.

Here, if S〈F2, then from equation (1) ―≦! Substituting equation (4) into equation (5), we get Ichiriki, from formula (2) Substituting equation (4) into equation (7), we get becomes.

In order for a stereoscopic photograph to be completely visible at the distance of human clear vision, 2 should be equal to the distance of clear vision and V should be larger than the distance between human eyes.

On the other hand, a photographic lens 1 used in a normal stereoscopic photography device
The exit pupil diameter D is 543 mm, and the focal length F is 152 mm.
Therefore, using these values as D and f, the focal length F2 of the field lens 5 is 152m7!1,200m
m, 250 mm, 300 m717, and 1 was calculated using equations (6) and (8) assuming infinity (none).

However, it is assumed that S=0, that is, the field lens 5 is in close contact with the lenticular sheet 2. Figures 3, 4, 5, 6 and 7 show the results of this calculation at a reduction rate of 1/5.
It is a diagram. In addition, the size of lenticular sheet 2 is 1.
00mm. In these figures, the photographing lens 1 is shown by a broken line parallel to the lenticular sheet 2, and the viewing area where stereoscopic vision is possible is shown by hatching. As you can see from Figure 3, the focal length F2 of the field lens is 152
mm (i.e., equal to the focal length of the photographic lens 1), the width of the viewing zone is approximately 50 mm from the lentichular sheet.
Unless they are farther apart than me, the distance between the eyes is 65 mm or more.

Therefore, it is necessary to observe from a distance of 50α or more. Moreover, as can be seen from FIG. 7, when a field lens is not used, the visual field is always narrower than the distance between the eyes. Therefore, complete stereoscopic vision is not possible. On the other hand, the 4th, 5th and 6th
As shown in the figure, when F2 = 200mm, if you are about 35cm away from the lenticular sheet, f2 is 250mm.
, 300 degrees, stereoscopic vision is possible if the distance is about 35 cIn.

From the above facts, in order to obtain a stereoscopic photograph that allows complete stereoscopic vision at almost the clear vision distance, if the specifications of the photographing lens 1 of the photographing device are determined as described above, the field lens 5 must be It can be seen that it is sufficient to set the focal length to around 200 to 300 mm.

As explained above, according to the stereoscopic photographing apparatus of the present invention, it is possible to photograph a stereoscopic photograph that can be viewed stereoscopically at a distance of clear vision.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram for explaining the outline of the stereoscopic photographing device, FIG. 2 is a diagram showing the optical system during photographing in the stereoscopic photographing device shown in FIG. , 6 and T are diagrams for explaining the viewing range in which stereoscopic vision is possible when photographing is performed with various focal lengths of the field lens. 1... Photographic lens, 2... Lenticular lens, 3... Photosensitive material, 4...
・Supporting member, 5...Field lens.

Claims (1)

[Claims] 1. A photographic lens, a lenticular sheet arranged perpendicular to the optical axis on the rear optical axis of the photographic lens, a support member that supports a photosensitive material in close contact with the back surface of the lenticular sheet, and In a stereoscopic photographic device having a field lens provided in front over substantially the entire lenticular sheet, the focal lengths of the photographing lens and the field lens are f_1 and f_2, respectively, and the diameter of the exit pupil of the photographing lens is D. When the distance between the field lens and the lenticular sheet is S, the distance between the position of the virtual image of the exit pupil and the lenticular sheet is l, and the diameter of the virtual image of the exit pupil is V, the formula l = (f_1f_2-2Sf_2- Sf_1+3
S^2)/(f_2-f_1+3S), V=Df_2/
In f_2-f_1+3S, l is almost at the distance of clear vision, and V is larger than the distance between human eyes,
A stereoscopic photography device characterized in that f_1, f_2, and S are set.