JPH07140569A - Stereoscopic image photographing method, prism used therefor and stereoscopic image photographing device - Google Patents

Abstract

PURPOSE:To more easily obtain a stereoscopic photography at a low cost by setting a pair of right and left prisms for separating the optical axis of a photographic lens for a camera into two right and left optical axes in front of the photographic lens and photographing an object. CONSTITUTION:The visual field of the camera 20 having a certain field angle is devided into right and left halves so that each of them may be the right image 22 and the left image 21 for the stereoscopic photography. At this time, combined Fresnel prisms are designed so that virtual optical axes 23 and 24 set on respective centers of the right and left images may become two parallel optical axes 23 and 24 after they pass through the combined Fresnel prisms, and the prisms are arranged in front of the photographic lens 26. Thus, an object is photographed at respective positions separated right and left by the distance (a) of a difference between the separated optical axes, so that a pair of stereoscopic photographs are obtained on a film. Besides, the distance between optical axes necessary for the stereoscopic photograph is usually the same as a distance between human eyes, so that a usual distance up to the combined Fresnel prisms is automatically decided in accordance with the decision of the field angle of the photographic lens.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and a photographing apparatus for photographing a stereoscopic image such as a stereoscopic photograph or a stereoscopic image, which is simpler and cheaper than conventional ones.

[0002]

2. Description of the Related Art A stereoscopic photograph or a stereoscopic image is obtained by taking a picture of the same subject from left and right angles and observing the paired images separately for the left and right eyes in some way. I will get it.

For example, the most general method for taking a three-dimensional photograph is to use two left and right taking lenses (1) as shown in FIG.
Using a stereoscopic camera (3) having (2),
As shown in FIG. 2, a subject is photographed at positions slightly apart from each other on the left and right, and a right-eye image (4) and a left-eye image (5) are simultaneously photographed on a film (8) to obtain a stereoscopic photograph. Alternatively, you can move left and right with a normal camera and take each one to get a stereoscopic picture, or in the case of aerial photography, you can shoot the ground from the same moving aircraft and use the overlapping range as a stereoscopic image. .

In any case, the two images thus obtained are arranged horizontally as shown in FIG. 3, and the image for the right eye (4) passes through the observation lens for the right eye (6) to the right eye (R).
Then, the left-eye image (5) is viewed through the left-eye observation lens (7) with the left eye (L) to obtain a stereoscopic image.

As described above, generally, a dedicated camera is used to obtain a stereoscopic photograph or a plurality of moving photographings are carried out, and the equipment is expensive or the photographing is large. there were. Therefore, there has been a demand for a simpler and cheaper means for obtaining a three-dimensional photograph.

[0006]

As a result of studies in view of this, the present invention has developed a stereoscopic image capturing method, a prism used therefor, and a stereoscopic image capturing apparatus that can achieve the above object.

That is, according to the three-dimensional image photographing method of the present invention, the left and right sides of the optical axis of the photographing lens of the camera are separated into two right and left optical axes.
It is characterized in that a pair of prisms is installed in front of the photographing lens to perform photographing.

The stereoscopic image taking prism of the present invention is
It is characterized in that the ridgelines having apex angles of the two triangular prisms are respectively directed to the outside and the bottom faces facing the apex are formed in close contact with each other.

Another prism for photographing a stereoscopic image according to the present invention is such that a ridgeline of a triangular prism of the same shape is brought into contact with a bottom face of a ridgeline of a triangular prism having an apex angle in parallel with the ridgeline of the above-mentioned prism. It is characterized in that two linear Fresnel prisms that are continuously formed by repeating a unit structure that is embedded and integrated are formed with their ridge lines facing outward and their bottom faces closely contacting each other. is there.

Further, one of the photographing devices of the present invention is a photographing lens of a camera, in which a combination prism is formed in which two ridges having apex angles of two triangular prisms are directed outward and the bottom faces facing the apex are closely adhered to each other. It is characterized by being installed in front of.

In another embodiment of the photographing apparatus of the present invention, the ridge of the triangular prism prism of the same shape is brought into contact with the bottom face of the prism having the apex angle of the prism in parallel with the ridge of the prism of the prism. Two linear Fresnel prisms that are continuously formed by repeating a unitary structure that is embedded and integrated, with the combined Fresnel prisms with their ridge lines facing outward and their bottom faces closely contacting each other It is characterized by being installed in front of the lens.

It is effective to detachably attach an attachment having a rotary ring to which the above-mentioned combined prism or combined Fresnel prism is attached to the photographing lens portion of the camera, or to stack a plurality of combined prisms or combined Fresnel prisms.

According to another aspect of the present invention, the above combined prism or combined Fresnel prism is detachably attached to the pedestal to which the camera is attached, or the combined Fresnel prism is unfolded or folded, and the combined prism or the combined Fresnel prism is provided in front of the taking lens during photographing. The pedestal is integrated with the camera case, and the pedestal that can be fixed to a tripod is more effective. The camera referred to in the present invention is a photographic device or a video camera device.

[0014]

The triangular prism can change only the direction of this optical axis without changing the size of the image passing through it. That is, when looking at a certain direction with the eyes, by placing a triangular prism in the middle of this line of sight, it is possible to see another direction forming an angle (θ) from the beginning without changing the direction of the line of sight. As shown in Fig. 4, two triangular prisms (10) (10 ') have ridges (1
Bottom faces (12) facing the apex, with 1) facing outwards
According to the combined prism formed by closely adhering to each other, the diffusing optical axes can be aligned in parallel, so if the camera is placed on the side where the optical axes converge, a stereoscopic photograph will be obtained as described later. The effect of such a combined prism can also be obtained by a combined Fresnel prism using a linear Fresnel prism as described below.

Here, the linear Fresnel prism (16) is
For example, as shown in FIG. 5, a plurality of triangular prisms (13) having the same shape with a right-angled triangular cross section are formed so that the surfaces forming the right angle and the apex angle (14) are in the same plane, and the apex portions (1
4) is a continuous structure in which the unit structure in which the 4) is formed in the bottom surface (15) of another triangular prism (13) is repeatedly formed, and only the direction of the optical axis is changed like the triangular prism of FIG. In addition, since it is thin and sheet-like, it can be easily manufactured in a large amount with transparent plastic by injection molding or casting.

As another example of the linear Fresnel prism, as shown in FIG. 6 (a), a triangular prism (13 ') having an isosceles triangular cross section is another triangular prism having the same apex angle (14). Of a plate-like body having longitudinal grooves on both sides, in which unit structures embedded in the bottom surface (15) of the above are repeatedly connected continuously, or as shown in FIG. The continuous repeating body of triangular prisms may have a unit structure in which a ridgeline (11) having an apex is continuously abutted in the longitudinal direction (longitudinal direction) of the bottom surface (15).

The principle of taking a three-dimensional photograph will be explained by using two such linear Fresnel prisms and symmetric symmetrical Fresnel prisms formed by closely adhering the bottom faces facing the apex angle with their ridge lines facing outward. To do. As shown in FIG. 7, the field of view of the camera (20) having a certain angle of view is divided into left and right halves so that each becomes the left image (21) and the right image (22) of the stereoscopic photograph. At this time, the provisional optical axes (23, 24) set at the centers of the left and right images pass through the combined Fresnel prism (25) and then two parallel optical axes (2
3) The combined Fresnel prism (2
By designing 5) and arranging it in front of the taking lens (26), it is possible to take pictures of the subjects at positions separated left and right by the distance a, which is the difference between the separated optical axes. can get. In the figure, c indicates the original optical axis of the taking lens (26) of the camera.

At this time, the angle of view of the photographing lens and the distance from the lens (26) to the combined Fresnel prism (25),
The relationship between the separated optical axis and the angle of view α of the photographing lens, and β = α / 4 the distance b from the lens to the combined Fresnel prism, and the separated optical axis distance a Then, the relationship of a = 2b tan β = 2b tan (α / 4) is established, and the optical axis distance required for stereoscopic photography is generally regarded as the distance between human eyes. Therefore, if the angle of view of the projection lens is determined, the combination is possible. The typical distance to the Fresnel prism is automatically determined.

In order to make the combined prism and combined Fresnel prism (hereinafter referred to as combined prism) of the present invention compatible with zoom lenses and lenses having different angles of view, a plurality of these may be used in superposition. Further, when used together with a wide-angle lens, image distortion may be a problem at the edge of the image. In this case, it is effective to use a distortion correction lens such as a convex lens or a concave lens as needed. To reduce such image distortion, as shown in FIG. 8, the left and right prisms (27) (2) of the combined prism are used.
It is also effective to arrange 7 ') so that they are orthogonal to the diffused right and left optical axes.

[0020]

EXAMPLES Examples of the present invention will be described in detail below.

(Example 1) As shown in FIG. 9, a rotating ring (32) having a combination prism (30) fixed to the front surface of an attachment (31) which can be screwed into a lens portion of a camera was produced. According to such an attachment (31), the combined prism can be easily set in front of the taking lens of the camera, so that a stereoscopic photograph can be easily obtained. In the figure, (33) shows an adjusting lever, and (34) shows a screw portion for attaching to the camera.
If you want to increase the distance between the separated parallel optical axes,
As shown in 10, an attachment (31 ') having a longer body may be used.

(Embodiment 2) As shown in FIG. 11, a foldable combination prism (30) is attached to the front end of a camera fixing base (37) for fixing a small camera or a disposable camera (35) with a screw (36). . The fixed base (37) may be fixed to a tripod or the like. According to the image capturing apparatus having such a configuration, a stereoscopic photograph can be easily obtained even with a camera to which an attachment cannot be attached as in the first embodiment.

(Embodiment 3) Further, as shown in FIG. 12, it is a case for accommodating a camera (35) and a camera fixing base (37) is formed by unfolding, and a combination prism (30) is formed on one side surface. The camera case (40) that was also used as the stereoscopic photography device was made of transparent plastic. In such a case, since the combined prism portion can be integrally formed by injection molding of plastic or the like, an inexpensive device can be obtained. Reference numeral (38) is a finder portion on the case side.

(Embodiment 4) As shown in FIG. 13, a front plate of a case accommodating a small camera or a disposable camera (35) is horizontally developed by a first stage rotating shaft (41), and further, two stages at the tip thereof. A camera case (43) also serving as a three-dimensional photography apparatus having a structure in which the combination prism (30) is raised by the eye rotation axis (42) to stand upright in front of the taking lens (26) of the camera was produced. With such a device, it is not necessary to take out the camera body from the camera case, and a stereoscopic photograph can be easily taken.
Note that such a combination prism is not a foldable prism
It may be inserted and attached to the tip of the front plate that is horizontally expanded by the step rotation shaft (41).

(Embodiment 5) As shown in FIG. 14, the rotary cover (46) covering the upper surface and the front surface of the camera case (45) is covered with a transparent acrylic resin so that the front end surface of the rotary cover (46) becomes a combined prism (30). It was molded integrally with. Then, one end of the rotary cover (46) is attached to the rotary shaft (47) of the case body, and combined with the stopper (48) so as to be installed at a predetermined position in front of the taking lens (26) of the camera (35). Configured to. According to such a camera case (45) also used as a stereoscopic photography device, as shown in FIG. 15 (a), the rotary cover (46) is set in the front to take a picture, and conversely, the stereoscopic picture taken in this way is taken. As shown in FIG. 15 (b), the camera (35) can be removed from the photograph (50) from the camera case (45), and the photograph (50) can be installed on the rear surface of the case to provide a stereoscopic photography observation tool.

At this time, in order to stereoscopically view a stereoscopic photograph, a right eye observing lens (6) and a left eye observing lens (7) as shown in FIG. 3 may be used in place of the combination prism (30). Alternatively, instead of the combination prism, as shown in FIG. 16 (a), an inverse combination prism (51) in which a ridgeline (11) of a triangular prism (10) faces inward in the opposite direction to the combination prism of the present invention. ) Or an inverse combination Fresnel prism (52) in which the linear Fresnel prism (16) is combined in the direction opposite to the configuration of the present invention as shown in FIG. 16 (b). Since such an inverse combination prism or an inverse combination Fresnel prism diffuses the line of sight to the outside, a stereoscopic effect can be obtained by viewing a stereoscopic photograph.

(Embodiment 6) As shown in FIG. 17, a combination prism (30) for stereoscopic photography is attached to the front end of a fixed base (61) for fixing a video camera (60) with a screw (36), and the inside thereof is attached. A three-dimensional image pickup device was produced in which an auxiliary lens (62) for wide-angle shooting was attached by means of a rotating shaft (63) so that it could be raised and lowered. With such a device, a right-eye screen and a left-eye screen for stereoscopic viewing can be obtained when a video is played back, so that a stereoscopic image can be obtained by viewing the screen using the inverse combination prism as shown in FIG. can get.

[0028]

The present invention has the following effects. (1) Realization of stereoscopic photography by a very simple method using a lightweight combined prism using a linear Fresnel prism. (2) The combined prism of the present invention can be mass-produced inexpensively by molding or molding. (3) Since the Fresnel prism is in the form of a sheet, it can be easily assembled in a camera case or the like, and a stereoscopic photography function can be added to the camera as easily as an interchangeable lens. (4) Stereoscopic images can be taken with a video camera.

[Brief description of drawings]

FIG. 1 is a perspective view showing a conventional stereoscopic camera.

FIG. 2 is an explanatory diagram showing the principle of a conventional stereoscopic camera.

FIG. 3 is an explanatory diagram showing an example of a stereoscopic image observation apparatus.

FIG. 4 is an explanatory view showing a combined prism of the present invention.

5A and 5B show an example of a linear Fresnel prism used in the present invention. FIG. 5A is a plan view and FIG. 5B is a perspective view.

FIG. 6 is a plan view showing another example of the linear Fresnel prism (a) and (b).

FIG. 7 is an explanatory diagram showing the principle of the device of the present invention.

FIG. 8 is an explanatory diagram showing an example of reducing image distortion according to the present invention.

9A and 9B show an example of a combined prism of the present invention, in which FIG. 9A is a perspective view and FIG. 9B is a side sectional view.

FIG. 10 shows another example of the same, (a) is a perspective view and (b) is a side sectional view.

FIG. 11 is a perspective view showing an example of the device of the present invention.

FIG. 12 is a perspective view showing another example of the device of the present invention.

13A and 13B show still another example of the device of the present invention, FIG. 13A is a side view in a stored state, FIG. 13B is a side view in a developed state, and FIG. 13C is a perspective view.

14A and 14B show still another example of the present invention, in which FIG. 14A is a side view in a stored state, and FIG. 14B is a side view in a developed state.

15A is a perspective view showing an example of a usage state of the device of the present invention, and FIG. 15B is a perspective view showing a state of observing a stereoscopic photograph.

FIG. 16 is a plan view showing an inverse combination prism used when observing a three-dimensional photograph, in both (a) and (b).

FIG. 17 is a perspective view showing still another example of the device of the present invention.

[Explanation of symbols]

 1, 2 Photographing lens 3 Stereoscopic camera 4 Image for right eye 5 Image for left eye 6 Observation lens for right eye 7 Observation lens for left eye 10 Triangular prism 11 Ridge line 12 Bottom surface 13 Trigonal prism 14 Bottom angle 15 Bottom surface 16 Linear Fresnel prism 20 Camera 21 Left side Image 22 Right image 23, 24 Temporary optical axis 25 Combination Fresnel prism 26 Lens 27, 27 'Combination prisms 30 Combination prism 31 Attachment 32 Rotation ring 33 Adjustment lever 35 Disposable camera 36 Set screw 35 Camera fixing base 38 Viewfinder 40 Camera case that also serves as a stereoscopic photography device 41 First stage rotating shaft 42 Second stage rotating shaft 43, 45 Camera case 46 Rotating cover 47 Rotating shaft 48 Stopper 50 Stereoscopic photo 51 Reverse combination prism 52 Reverse combination Fresnel prism 60 Video camera 61 Fixed Table 62 Auxiliary lens for wide-angle shooting 63 Rotation axis

Claims (11)

[Claims] 1. A method for photographing a stereoscopic image, wherein a pair of right and left prisms for separating an optical axis of a photographing lens of a camera into two optical axes of right and left are installed in front of the photographing lens to perform photographing. . 2. A combination prism for stereoscopic imaging, wherein two ridges having apex angles of two triangular prisms are directed to the outside, and bottom faces facing the apex are formed in close contact with each other. 3. A unit structure in which the ridgeline of the triangular prism of the same shape is made parallel to the ridgeline of the above-mentioned triangular prism and abuts or is embedded on the bottom face opposite to the ridgeline having the apex angle of the triangular prism, and the unit structure is repeated. A combined Fresnel prism for stereoscopic image capturing, wherein two linear Fresnel prisms that are continuously formed are formed so that their ridge lines face outward and their bottom faces closely contact each other. 4. A combination prism in which two ridges having apex angles of two triangular prisms are directed to the outside and bottom surfaces facing the apex are closely attached to each other are installed in front of a taking lens of a camera. 3D image capturing device. 5. A unit structure in which a ridgeline of a triangular prism of the same shape is parallel to the ridgeline of the above-mentioned triangular prism and abuts or is embedded on the bottom face opposite to the ridgeline having the apex angle of the triangular prism, and the unit structure is repeated. It is characterized in that two linear Fresnel prisms that are continuously formed are installed in front of a taking lens of a camera, with a combined Fresnel prism in which their ridge lines are directed outward and their bottom faces are in close contact with each other. 3D image capturing device. 6. The stereoscopic image capturing apparatus according to claim 4, wherein an attachment having a rotating ring to which a combination prism or a combination Fresnel prism is attached is detachably attached to a taking lens portion of a camera. 7. A combination prism or a combination Fresnel prism as claimed in claim 4, wherein a plurality of combination prisms are superposed.
A stereoscopic image capturing device according to the item. 8. The combined prism according to claim 1 or the combined Fresnel prism according to claim 2 is detachably attached or unfolded or foldable to a pedestal for mounting a camera, and the combined prism or the combined Fresnel prism is installed in front of a taking lens during photographing. A stereoscopic image capturing device characterized by: 9. The stereoscopic image capturing apparatus according to claim 8, wherein the pedestal is integral with the camera case. 10. The pedestal can be fixed to a tripod.
Alternatively, the stereoscopic image capturing apparatus according to Item 9. 11. The stereoscopic image capturing apparatus according to claim 4, wherein the camera is a camera or a video camera.