JP2857363B2 - Stereo camera - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stereo camera, and more particularly to a reflex type stereo camera having an improved finder.

[0002]

2. Description of the Related Art
2. Description of the Related Art A reflex stereo camera in which two single-lens reflex camera optical systems are mounted on one camera body is known. The viewfinder of this type of reflex type stereo camera uses the pentaprism of a single-lens reflex camera, but as is well known, the pentaprism requires precision processing, so the manufacturing cost is extremely high and two pentaprisms are used. The cost of a stereo camera is high.

Further, a structure in which two viewfinders are arranged in parallel and a finder image is viewed with both eyes is not always easy to see. In particular, due to restrictions on the outer diameter of a lens and the size of a lens mount mechanism, two systems are used. In a stereo camera in which the pitch of the optical system is longer than the distance between human eyes (approximately 63.5 mm), it is difficult to look into two viewfinders at the same time. Therefore, it is often the case that one of the viewfinders is used to shoot an image, and the other viewfinder screen is neglected, and an obstacle is photographed on one of the screens, or raindrops or dust adhere to one of the lenses. Shooting may fail.

In view of the above, the right and left reticle images can be viewed with a single finder to improve visibility and operability, and a technical solution to be solved in order to simplify the finder configuration and reduce costs. Problems arise, and the present invention aims to solve the above problems.

[0005]

SUMMARY OF THE INVENTION The present invention proposes to achieve the above-mentioned object, in which an optical system of a single-lens reflex camera comprising a lens, a reflex mirror and a prism is mounted on a single camera body. In a reflex type stereo camera equipped with two systems so that the incident images of the left and right lenses can be observed through a reflex mirror and a prism, a screen of each of the outer half of the photographing range of the left and right lenses is displayed. A stereo camera characterized by having a compound prism that symmetrically inverts left and right to synthesize one erect image, and formed so that the outer half of each of the photographing ranges of the left and right lenses can be observed with one eye. Is provided.

Further, the center distance between the left and right lenses is formed so as to be adjustable, and an interlocking mechanism is interposed between the focus adjustment mechanism and the center distance adjustment mechanism between the lenses, so that the photographing range of the left and right lenses at the focal distance is obtained. Are provided so as to always match.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a stereo camera 1 according to the present invention, in which a slide frame 3 is mounted on a camera body 2 so as to be slidable back and forth, and two lenses 4 and 5 are mounted on the front surface of the slide frame 3. By rotating the focus adjustment dial 6, the slide frame 3 moves back and forth through an adjustment mechanism (not shown) such as a feed screw mechanism or a cam mechanism, and can adjust the focus of the lenses 4 and 5.

Light rays incident through the lenses 4 and 5 are reflected upward by the reflex mirrors 7 and 8 to form images on the focusing screens 9 and 10. A compound prism 11 is disposed above the focusing plates 9 and 10, and images on the left and right focusing plates can be viewed through the eyepiece 12. Reference numeral 13 denotes a shutter button, and a focal plane shutter (not shown) is provided behind the reflex mirrors 7, 8. It is desirable that the center pitch of the lenses 4 and 5 is about 63.5 mm, which is the distance between the human eyes.

The prism 11 is formed by integrally forming two systems of total reflection prisms using optical resin or optical glass as a material in a bilaterally symmetric manner. As shown in FIG. 2, two 180 ° reflection prisms joined in parallel are provided. The shape is such that 90-degree reflecting prism portions 15L and 15R that allow light rays from below to be incident are bonded to the outer half of each of the incidence surfaces of the prism portions 14L and 14R. Then, the 180-degree reflecting prism section 14L,
Each of the inner 1/2 incident surfaces of the 14R constitutes one continuous projection surface 16.

[0010] As shown in FIG.
The vertex pitch P ₂ of the reflection prism portions 14L and 14R is
This is の of the center pitch P ₁ of the left and right exposure screens, and the total width W is slightly wider than the screen pitch P ₁ .

As shown in FIG. 4, the prisms 11 are disposed on the left and right reticle plates with the incident surfaces of the left and right 90-degree reflecting prism portions 15L and 15R facing the inner half area of the reticle plates 9 and 10, respectively. 90-degree reflecting prism portions 15L, 15 from below
The ray incident on R is totally reflected three times and emerges from the projection surface 16 in the horizontal direction.

The inverted left-right inverted image that has passed through the lenses 4 and 5 is turned upside down by the reflex mirrors 7 and 8, and the image on the reticle plates 9 and 10 is an upright left-right inverted image. , 10 of each inner half screen, ie,
The outer half of each of the photographing ranges of the left and right lenses 4 and 5 is symmetrically reversed left and right by the prism 11. Accordingly, an erect erect image outside the shooting range of the left lens 5 is projected on the left half of the projection surface 16 of the prism 11, and the shooting range of the right lens 4 is projected on the right half of the projection surface 16. Is projected, and one screen is synthesized.
The focusing screens 9 and 10 do not need to have the same size as the screen, and may have the same size as or slightly larger than the incidence surface of the prism 11 which is almost half the screen size.

FIGS. 5 and 6 show another embodiment of the prism. The prism 21 is a prism 11 shown in FIG.
Conversely, the right and left 1 /
2 have a shape in which the inner half of the projection surfaces of the 180-degree reflecting prism portions 23L and 23R are joined to each other. However, like the prism 11 shown in FIG. , 180-degree reflecting prism section 23L, 2
The vertex pitch and overall width of the 3R are the same as those of the prism 11.

As shown in FIG. 6, the 180-degree prism sections 23L, 23 of the prism 21 installed on the focusing screens 9, 10 are provided.
Left and right focusing screens 9 and 1 on the outer I / 2 incidence surfaces of 3R
0 of each image is incident on the reflection surface RP
1, RP2 and RP3 make three total reflections, and an erect erect image combined into one screen is projected on the central projection surface 24 by left and right 1/2 screens.

Incidentally, the incidence surfaces of the prisms 11 and 21 facing the reflex mirrors 7 and 8 may be subjected to mat processing to form a ground glass-like focal plane, and the focusing plates 9 and 10 may be omitted. Further, the reflection surface RP of the prisms 11, 21, 34
Aluminum, etc. may be deposited on 1, RP2 and RP3 to form a mirror surface.

FIGS. 7 to 10 show another embodiment. The focus adjusting mechanism of the stereo camera 31 shown in FIG. 7 is the same as that of the stereo camera 1 of FIG. 1, but the finder mechanism rotates in the horizontal direction. Vertical reflex mirrors 32, 33
And a prism 34 inserted between the left and right reflex mirrors 32, 33.

As shown in FIG. 8, the prism 34 has 90-degree reflection on each of the left and right halves of the lower incidence surface of the 180-degree reflection prism portion 35 for vertically displacing the optical paths of the incident light and the reflected light. The prism portions 36L and 36R are joined together, and the incident surface of the 90-degree reflecting prism portions 36L and 36R is a vertical surface facing the outside in the lateral direction. As shown in FIG. 9, the total width W of the prism 34 is の of the center pitch P ₁ of the left and right exposure screens of the stereo camera.

The vertical reflex mirrors 32 and 33 arranged on the left and right sides of the prism 34 are provided with a pivot 3 shown in FIG.
2a and 33a are rotated in the horizontal direction about the center of rotation, and at the time of photographing, are rotated from the standby position of 45 degrees with respect to the main axis of light toward the side surface of the prism 34 and retracted from the optical path connecting the lenses 4 and 5 and the film surface. I do.

When the vertical reflex mirrors 32 and 33 are at the standby position, the outer half screens of the photographing ranges of the left and right lenses 4 and 5 are respectively displayed on the reflex mirrors 32 and 3.
The light is inverted left and right by 3 and enters the 90-degree reflecting prism portions 36L and 36R of the prism 34. Then, as shown in FIG. 10, the reflection surfaces RP1 of the 90-degree reflection prism portions 36L, 36R, RP2, R
Total reflection three times by P3, 180 degree reflection prism part 3
5 outside the shooting range of the left lens 5 on the upper projection surface 37
/ 2 outside the shooting range of the right lens 4
An aerial image combined with the two erect images appears.

In this stereo camera 31, since the prism 34 is inserted between the left and right exposure screens, the height of the camera can be significantly reduced. If the entrance surfaces of the 90-degree reflecting prism portions 36L and 36R of the prism 34 are subjected to matte processing to form a focal plane, a real image formed on the focal plane can be observed to adjust the focal point, thereby facilitating the focal point adjustment. .

FIG. 11 shows another embodiment of the stereo camera 31, in which a pair of left and right screens P1L and P1 on a film is shown.
Exposure screens are arranged so that another screen is arranged in two frames between R. In this case, since the vertical reflex mirrors 32 and 33 are disposed at positions away from the side surfaces of the prism 34, as shown in FIG. The reticle image is made incident on the prism 34 by disposing 39. If the condenser lenses 40 and 41 are arranged behind the focusing plates 38 and 39, the finder image becomes brighter and easy to see.

Note that, as shown in FIG.
1, 31 left and right lenses 4 and 5 are at infinity and the shooting range is
So that they are parallel and the central axis is the center of the exposure screen area
And each of the fields of view of the left and right lenses 4 and 5
To see the viewfinder image synthesized by the outside half
And the center pitch P of the lenses 4 and 5 and the left and right exposure screens
₁The central area heading to the left and right center of the shooting range with the width equal to
Out of sight. However, the area that cannot be seen is a narrow line
Yes, it is hidden within this range except during close-up shooting
There are few subjects. In addition, the stereo camera
You can see all subjects in the shooting range by shaking
There is no inconvenience in shooting because it can be done.

FIG. 13 shows a stereo camera 51 according to a second aspect of the present invention, in which a slide frame 53 slidable back and forth with respect to a camera body 52 is mounted similarly to the above-described stereo camera 1. A pair of lens boards 54 and 55 are mounted symmetrically on the front surface of the slide frame 53, and lenses 4 and 5 are mounted on the lens boards 54 and 55. A prism 11 or 21 and an eyepiece 12 are arranged above the focusing plates 9 and 10, similarly to the stereo camera 1 of FIG. The left and right lens boards 54 and 55 are mounted on the slide frame 53 so as to be slidable left and right.
The structure is such that the distance between 4,55 can be expanded and contracted symmetrically.

FIG. 14 shows a focus adjusting mechanism and a lens center-to-center adjusting mechanism. A feed screw 56 mounted horizontally on the front of the slide frame 53 has a left screw 56a formed on the left side and a right screw 56a formed on the right side. The screw 56b is formed. The female thread portion 54a of the left lens board 54 meshes with the left screw 56a, and the right lens board 5 engages with the right screw 56b.
The female threads 55a of the lens boards 5 and 5
5 can be centered pitch of the right and left lenses 4 and 5 is moved within a certain range of directions in which the right and left of the exposure surface pitch P ₁ becomes equal to the lens from the position approaches.

A cam shaft 57 is pivotally supported at a rear portion of the slide frame 53, and cams 58 for focus adjustment are fitted to both ends of the cam shaft 57. The slide frame 53 is urged rearward (upward in FIG. 14) by a spring (not shown), and the cam 58 is pressed against the cam receiving surface of the camera body 52, and the slide frame 53 is rotated according to the rotation of the cam shaft 57. Slides back and forth.

The feed screw 56 and the camshaft 57 are connected by spur gears 59 and 60. When an adjustment knob 61 attached to one end of the feed screw 56 is rotated, the lens board 54 and the cam shaft 57 are rotated.
The focus and the center-to-center distance of the lens are adjusted in conjunction with 55 and the slide frame 53. .

FIG. 15 shows the relationship between the focal point of the lens and the center-to-center distance. Assuming that the lens is one thin lens, the focal length of the lens ｆ f If the distance from the subject to the principal point of the lens Ｌ L The distance from the focal position of the lens to the image forming position ‥ Δif, then Δif = f ² / ( L−f ). The distance from the film surface is f + Δif.

Further, each of the shift amount Sl of the left and right lens for matching the imaging range in the left and right, when the pitch of the left and right exposed surface of the stereo camera to _{P 1, Sl = (P 1} /2) × (f + Δif ) / ( L + f + Δif), and as the distance L from the subject to the principal point of the lens decreases, the left and right lenses may be moved in the directions approaching each other by the shift amount S1 calculated from the above equation.

Therefore, the pitch of the feed screw 56 and the cam 58
Is shaped so as to satisfy the above formula, so that the slide frame 53 using the cam 58 as the moving means with respect to the lens boards 54 and 55 that move in proportion to the rotation angle of the adjustment knob 61, As the shooting distance becomes shorter, the feeding amount increases exponentially, and the left and right shooting ranges match regardless of the shooting distance.

Therefore, regardless of the shooting distance, the parallax of the subject is automatically corrected, and the subject at the in-focus position is
Since images are taken at substantially the same position on the left and right screens, there is almost no need to correct the parallax by adjusting the film pitch when mounting the film on the stereo slide mount. In addition, since the non-overlapping portions of the left and right screens to be covered by the windows of the slide mount are reduced, a stereo slide with less screen loss can be created.

The entire movable part including the lenses 4 and 5, the lens boards 54 and 55, and the slide frame 53 other than the camera body 52 shown in FIG. Lens units having various focal lengths in which the pitch of the feed screw and the shape of the cam are designed in accordance with the focal length of the lens can be used.

The state of parallax correction in the above-described stereo camera 51 can be confirmed by looking through the eyepiece lens 12. FIG. 16A shows a subject, and FIGS. 16B, 16C, and 16D show finder images. When the stereo camera is rotated in the horizontal direction and the subject shown in FIG. When the subject is in focus, the subject is located on the intersection of the left and right prism visual fields, and the subject looks like an actual shape as shown in FIG.

When the subject is located far from the focus position, that is, at the intersection of the left and right prism visual fields, it appears wide as shown in FIG. Become. On the other hand, when the subject is located at a short distance from the intersection of the left and right prism visual fields, the portion that enters the central blind spot is masked as described above, and appears narrow as shown in (d). As described above, by rotating the adjustment knob 61 so that the foreground subject in the finder image looks like an actual shape, it is possible to capture an image with the parallax corrected appropriately.

Also, parallax correction and focus adjustment may not be easy depending on the subject. In particular, when the subject is a vertical or horizontal line, it is difficult to determine the state of focus and parallax. In such a case, if the stereo camera is tilted left or right from the horizontal posture, the focus adjustment state can be easily visually recognized.

FIG. 17 shows a viewfinder image when the stereo camera is tilted left or right from the horizontal posture.
In the in-focus state, the linear object appears continuously as shown in FIG. 17A, but when the object is far from the in-focus position, the left and right images move in a direction in which the left and right images separate as shown in FIG. 17B. The linear object is divided at the center. In addition, when the subject is located at a short distance from the in-focus position, the right and left subjects approach each other. In this case, the linear subject is also divided at the center, so that it is possible to easily determine whether the focus adjustment and the parallax correction are appropriate.

In the stereo camera 1 according to the first aspect of the present invention, there are portions where the fields of view do not overlap each other outside the left and right photographing screens. It will be masked by the window frame of the mount.

The stereo camera 51 according to claim 2
, The parallax is corrected in conjunction with the focus adjustment, so there is almost no non-overlapping part on the left and right screens, but the image was taken in a state where the focused main subject was in the distant view and parallax correction for the near view subject was insufficient In such a case, it may be necessary to correct the parallax by masking the outer sides of the left and right photographic films at the time of mounting, as in the related art.

FIG. 18 shows a screen layout of a stereo camera proposed in view of the characteristics of the stereo camera which requires parallax correction at the time of mounting described above. This is because the edge of the screen of the film F is masked at the time of mounting. The exposure screens are arranged such that there is no gap between the respective screens P on the film, and an image is taken in a state where adjacent screens are in contact with each other. This maximizes the effective screen area with a limited screen pitch.

The present invention is not limited to the above embodiment. For example, the finder configuration of the stereo camera shown in FIGS. 7 to 11 is applied to the stereo camera 51 shown in FIG. Various modifications are possible within the technical scope, and it goes without saying that the present invention extends to those modifications.

[0040]

As described above in detail, in the stereo camera of the present invention, a screen obtained by connecting １ ／ of each of the left and right screens can be observed with one finder. Visibility is better than that of
Excellent operability. In addition, the conventional pentaprism
The manufacturing cost of the viewfinder is reduced compared to a stereo camera equipped with a single unit, and this can contribute to the cost reduction of a reflex type stereo camera.

Further, in the stereo camera according to the second aspect, it is possible to judge whether or not the parallax correction and the focus adjustment are successful based on the finder image, and to take an image in a state where the screen loss can be suppressed and the optimum stereo effect can be exhibited in advance. it can.

[Brief description of the drawings]

FIG. 1 is a front view of a stereo camera according to claim 1.

2 (a) is a rear view, FIG. 2 (b) is a plan view, FIG. 2 (c) is a front view, FIG. 2 (d) is a bottom view, and FIG. FIG. 7F is a side view.

FIG. 3 is an explanatory diagram showing the relationship between the dimensions of a prism and the pitch of a reticle.

FIG. 4 is a perspective view of the prism shown in FIG. 2;

5A and 5B show another embodiment of the prism, wherein FIG. 5A is a plan view, FIG. 5B is a front view, FIG. 5C is a bottom view, FIG. 5D is a rear view, and FIG. -A line arrow view, (f) is a side view.

FIG. 6 is a perspective view of the prism shown in FIG. 5;

FIG. 7 is a front view of a stereo camera showing another embodiment of the invention described in claim 1.

8 shows a prism of the stereo camera shown in FIG. 7,
(A) is a plan view, (b) is a front view, (c) is a bottom view,
(D) is a rear view, (e) is a view taken along line AA of (b),
(F) is a side view.

FIG. 9 is an explanatory view showing the arrangement of a prism and a reflex mirror of the stereo camera shown in FIG. 7;

FIG. 10 is a perspective view showing an arrangement of a prism and a reflex mirror of the stereo camera shown in FIG. 7;

FIG. 11 is an explanatory view showing another embodiment of the stereo camera shown in FIG. 7, showing the arrangement of prisms and reflex mirrors.

FIG. 12 is an explanatory diagram of a shooting range and a viewfinder field of the stereo camera shown in FIG. 1;

FIG. 13 is a front view of the stereo camera according to claim 2;

FIG. 14 is an explanatory diagram of a focus adjustment mechanism and a lens center-to-center distance adjustment mechanism of the stereo camera according to claim 2;

FIG. 15 is an explanatory diagram showing the relationship between the focus adjustment of the stereo camera according to claim 2 and the adjustment of the center distance of the lens.

16A is an explanatory diagram showing a finder image of a subject, and FIGS. 16B, 16C, and 16D are view diagrams each showing a finder image of the subject.

17 (a), (b) and (c) are explanatory diagrams each showing a finder image of a subject.

FIG. 18 is a front view of a film showing an exposure screen arrangement of the stereo camera.

[Explanation of symbols]

 Reference Signs List 1 stereo camera 3 slide frame 4,5 lens 6 focus adjustment dial 9,10 focusing plate 11,21 prism 12 eyepiece 31 stereo camera 32,33 reflex mirror 34 prism 51 stereo camera 54,55 lens board 56 feed screw 57 cam Shaft 58 Cam 61 Adjustment knob

Claims (2)

(57) [Claims] 1. An optical system of a single-lens reflex camera comprising a lens, a reflex mirror and a prism mounted on one camera body on the left and right, and an incident image of the left and right lenses is reflected via the reflex mirror and the prism. In a reflex-type stereo camera that can be observed, each of the left and right lenses has an outer half area.
A composite prism is provided that symmetrically inverts the screen horizontally and synthesizes one erect erect image, so that the outside 1/2 of the photographing range of the left and right lenses can be observed with one eye. Stereo camera. 2. The photographing range of the left and right lenses at the focal distance, wherein the center distance between the left and right lenses is formed so as to be adjustable, and the focusing mechanism and the lens center distance adjusting mechanism are interlocked with each other. Claim 1 formed so as to always match
The stereo camera as described.