JPH09244165A - Stereocamera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve visibility and operability by viewing right and left images through one finder in a reflex type stereocamera. SOLUTION: A prism 11 installed on the upper sides of the reticles 9 and 10 of a stereocamera 1 is a composite type prism where the left-and-right inversion prism of a left and right double system is integrally formed. The 1/2 of the respective insides of a left-and-right inversion image plane on the reticles 9 and 10 is inverted left and right by the prism 11, and the erect normal image of the 1/2 of the outside of the photographing range of a left lens 5 is projected on the left side of the center projection surface of the prism 11, and the erect normal image of the 1/2 of the outside of the photographing range of a right lens 4 is projected on a right side, so that one picture is synthesized.

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
A reflex type stereo camera is known in which an optical system of a single-lens reflex camera of two systems is mounted on one camera body. The finder of this type of reflex stereo camera uses the pentaprism of a single-lens reflex camera, but as is well known, the pentaprism requires high precision processing, so the manufacturing cost is extremely high and two pentaprisms are used. This is the reason why the price of stereo cameras is high.

Further, the structure in which two viewfinders are arranged in parallel and the viewfinder image is viewed with both eyes is not always easy to see. Especially, due to the restrictions of the outer diameter of the lens and the size of the lens mount mechanism, two systems are used. In a stereo camera in which the pitch of the optical system is equal to or greater than the human eye distance (approximately 63.5 mm), it is difficult to look through the two viewfinders at the same time. Therefore, it is often the case that one of the viewfinders is used for shooting, and the screen of the other viewfinder is neglected, and an obstacle is shot on one screen, or raindrops or dust adhering to one lens. Sometimes shooting fails.

Therefore, the left and right focusing screen images can be viewed with a single finder to improve the visibility and operability, and at the same time, a technical problem to be solved in order to simplify the structure of the finder and reduce the cost. Problems arise, and an object of the present invention is to solve the above problems.

[0005]

SUMMARY OF THE INVENTION The present invention is proposed in order to achieve the above-mentioned object, and an optical system of a single-lens reflex camera consisting of a lens, a reflex mirror and a prism in one camera body is left and right. In the reflex type stereo camera, which is equipped with two systems on the left and right side and allows observation of the incident images of the left and right lenses through a reflex mirror and prism, A stereo camera characterized by being provided with a compound prism that symmetrically flips right and left and synthesizes one erect image so that the outer half of the shooting range of the left and right lenses can be observed with a single 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 adjusting mechanism and the center distance adjusting mechanism for the lenses, so that the photographing range of the left and right lenses at the focusing distance is increased. The present invention provides a stereo camera formed 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 a first aspect of the present invention, in which a slide frame 3 is attached to a camera body 2 so as to be slidable back and forth, and two lenses 4 and 5 are attached to the front surface of the slide frame 3. By rotating the focus adjustment dial 6, the slide frame 3 can be moved back and forth via an adjustment mechanism (not shown) such as a feed screw mechanism or a cam mechanism to 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 and focused on the focusing screens 9 and 10. A composite prism 11 is disposed above the focusing screens 9 and 10, and images on the left and right focusing screens can be viewed through the eyepiece lens 12. A shutter button 13 is provided with a focal plane shutter (not shown) behind the reflex mirrors 7 and 8. The center pitch of the lenses 4 and 5 is preferably about 63.5 mm, which is the distance between both eyes of a human.

The prism 11 is a birefringent total reflection prism integrally formed from optical resin or optical glass as a material, and as shown in FIG. 2, two 180 degree reflection prisms joined in parallel. It is a shape in which 90 ° reflection prism portions 15L and 15R that make light rays from below enter are joined to the outer half of the incident surfaces of the prism portions 14L and 14R, respectively. Then, the 180-degree reflecting prism portion 14L,
The incident surface of the inner half of each of 14R constitutes one continuous projection surface 16.

As shown in FIG.
The apex pitch P ₂ of the degree reflection prisms 14L and 14R is
It is half 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 prism 11 is arranged on the left and right focusing plates with the entrance surfaces of the left and right 90-degree reflecting prism portions 15L and 15R facing the inner half areas of the focusing plates 9 and 10. , 90 ° reflection prism parts 15L, 15 from below
The light ray incident on R is totally reflected three times and exits 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 inverted upside down by the reflex mirrors 7 and 8, and the images on the focusing screens 9 and 10 are erecting left-right inverted images. , 10 inside 1/2 screen respectively, that is,
The outer half of the photographing range of each of the left and right lenses 4 and 5 is symmetrically left and right inverted by the prism 11. Therefore, an erect image of the outer half of 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 on the right half of the projection surface 16. An outer half erect image is projected to synthesize one screen.
The focusing screens 9 and 10 do not have to have the same size as the screen, but may have the same size as or slightly larger than the incident surface of the prism 11 which is approximately ½ of the screen size.

5 and 6 show another embodiment of the prism, and the prism 21 is the prism 11 shown in FIG.
On the contrary, the left and right 1/90 of the central 90-degree reflecting prism portion 22
2 has a shape in which the inner half of the projection surface of each of the 180-degree reflection prism portions 23L and 23R is joined, but like the prism 11 shown in FIG. 2, it is an optical configuration that totally reflects a light ray three times. , 180 degree reflection prisms 23L, 2
The vertex pitch and the total width of 3R are the same as those of the prism 11.

As shown in FIG. 6, the 180-degree prism portions 23L and 2L of the prism 21 installed on the focusing screens 9 and 10, respectively.
Left and right focusing screens 9 and 1 to the outer I / 2 incident surfaces of 3R, respectively.
The image of the inner half of 0 is incident and the reflection surface RP
Totally reflected three times by 1, RP2, RP3, and an erect normal image combined on one screen is projected on the central projection surface 24 by left and right half screens.

The incident surfaces of the prisms 11 and 21 facing the reflex mirrors 7 and 8 may be matted to form frosted glass-like focal planes, and the focusing plates 9 and 10 may be omitted. In addition, the reflecting surfaces RP of the prisms 11, 21, 34
A mirror surface may be formed by vapor-depositing aluminum or the like on 1, RP2 and RP3.

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 horizontally. Vertical reflex mirror 32, 33
And a prism 34 inserted between the left and right reflex mirrors 32, 33.

As shown in FIG. 8, the prism 34 reflects 90 degrees on each of the left and right sides of the lower incidence surface of the 180-degree reflection prism portion 35 which vertically displaces 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 outer lateral direction. Further, as shown in FIG. 9, the total width W of the prism 34 is 1/2 of the center pitch P ₁ of the left and right exposure screens of the stereo camera.

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

When the vertical reflex mirrors 32 and 33 are in the standby position, the screens that are 1/2 outside the photographing range of the left and right lenses 4 and 5 are reflex mirrors 32 and 3, respectively.
It is horizontally reversed by 3 and enters the 90-degree reflecting prism portions 36L and 36R of the prism 34. Then, as shown in FIG. 10, the reflecting surfaces RP1 of the 90-degree reflecting prism portions 36L and 36R, and the RP2 and R of the 180-degree reflecting prism portion 35.
Totally reflected three times by P3, 180 degree reflection prism part 3
The upper projection surface 37 of the lens 5 is located outside the photographing range of the left lens 5 1
Erect image of / 2 and outside the shooting range of the right lens 4 1 /
The aerial image synthesized by the two erect images.

In this stereo camera 31, since the prism 34 is inserted between the left and right exposure screens, the height dimension of the camera can be remarkably reduced. If the incident surfaces of the 90-degree reflecting prisms 36L and 36R of the prism 34 are matted to form focal planes, the real image formed on the focal planes can be observed and the focusing can be performed, facilitating the focusing. .

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

As shown in FIG. 12, a stereo camera
The left and right lenses 1 and 31 4 and 5 have an infinite shooting range
Parallel and the central axis is the center of the exposure screen area so that they match.
Located on the right and left sides of the left and right lenses 4 and 5, respectively.
Looking at the viewfinder image synthesized by the outer half
Then, the center pitch P of the lenses 4 and 5 and the left and right exposure screens
₁The central area, which has the same width as
It is out of the field of view. However, the area that cannot be seen is a narrow line.
Yes, it cannot be seen because it is hidden within this range except during close-up photography
There are almost no subjects. Also, set the stereo camera horizontally.
You can see all the subjects in the shooting range by shaking
Since it can be done, there is no inconvenience in shooting.

FIG. 13 shows a stereo camera 51 according to a second aspect of the present invention. As with the stereo camera 1 described above, a slide frame 53 that is slidable back and forth is attached to a camera body 52. A pair of lens boards 54 and 55 are symmetrically mounted on the front surface of the slide frame 53, and lenses 4 and 5 are mounted on the lens boards 54 and 55. Further, above the focusing screens 9 and 10, a prism 11 or 21 and an eyepiece lens 12 are arranged as in 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, and the lens board 5 is attached by a feed screw mechanism.
It has a structure in which the distance between the four and fivety-five can be symmetrically expanded and contracted.

FIG. 14 shows a focus adjusting mechanism and a lens center-to-center distance adjusting mechanism. The feed screw 56 horizontally mounted on the front part of the slide frame 53 has a left screw 56a formed on the left side and a right screw on the right side. The screw 56b is molded. Then, the female screw portion 54a of the left lens board 54 is engaged with the left screw 56a, and the right lens board 5 is engaged with the right screw 56b.
5 of the female screw portion 55a is engaged with the lens board 54, 5
5 can be moved within a certain range in the direction in which the lenses approach from the position where the center pitch of the left and right lenses 4, 5 is equal to the left and right exposure surface pitch P ₁ .

A cam shaft 57 is rotatably supported at the 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 biased rearward (upward in FIG. 14) by a spring (not shown), 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 cam shaft 57 are connected by spur gears 59 and 60. When the adjusting knob 61 attached to one end of the feed screw 56 is rotated, the lens board 54 and
55 and the slide frame 53 are interlocked with each other to adjust the focal point and the distance between the centers of the lenses. .

FIG. 15 shows the relationship between the focal point of the lens and the center-to-center distance. It is assumed that the lens is one thin lens, and the focal length of the lens is ... f. if the distance ‥ Derutaif from the focal position of the distance ‥‥‥‥ L lens from the subject to the principal point of the lens to the imaging position, since it is ^{Δif = f 2 / L-f} , principal point and the film plane of the lens The distance between and 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 toward each other by the shift amount Sl calculated from the above equation.

Therefore, the pitch of the feed screw 56 and the cam 58
The slide frame 53 having 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 by shaping the shape of the above-mentioned equation so as to satisfy the above-mentioned formula, 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 the images are taken at almost the same positions on the left and right screens, it is almost unnecessary to adjust the film pitch to correct the parallax 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. It is possible to use lens units having various focal lengths in which the pitch of the feed screw and the shape of the cam are designed according to the focal length of the.

The state of parallax correction in the above-described stereo camera 51 can be confirmed by looking through the eyepiece lens 12. 16A shows the subject, and FIGS. 16B, 16C, and 16D show the viewfinder 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 at the intersection of the left and right prism visual fields, and the subject looks like an actual shape as shown in (b).

When the object is at the in-focus position, that is, at a distance farther than the intersection of the left and right prism fields of view, it looks wide as shown in FIG. 7C, and when the object is far away, it is divided into left and right double images. Become. On the other hand, when the subject is closer than the intersection of the left and right prism fields of view, the portion that entered the central blind spot is masked as described above, and appears narrow as shown in (d). In this way, by rotating the adjustment knob 61 so that the near object in the viewfinder image looks like an actual shape, it is possible to take an image with the parallax properly corrected.

Depending on the subject, parallax correction and focus adjustment may not be easy, and especially when the subject is a vertical line or horizontal line, it is difficult to determine the focus and parallax state. In this case, if the stereo camera is tilted to the 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 to the left or right from the horizontal posture,
In the in-focus state, the linear subject appears to be continuous as shown in FIG. 17A, but when it is far from the in-focus position, the left and right images move in the direction of separation as shown in FIG. 17B. The linear subject is divided at the center. Further, when the subject is on a short distance from the in-focus position, the left and right subjects approach each other, and in this case also the linear subject is divided at the center, so that it is possible to easily determine whether or not focus adjustment and parallax correction are appropriate.

In the stereo camera 1 according to the above-mentioned claim 1, there are portions where the fields of view do not overlap outside the left and right photographing screens, and the non-overlapping portions are stereo slides as is conventionally done. It will be masked by the window frame of the mount.

A stereo camera 51 according to a second aspect of the present invention.
Since the parallax is corrected in conjunction with the focus adjustment, there is almost no non-overlapping part on the left and right screens, but the main subject in focus is in the distant view and the parallax correction for the near subject was insufficient. In this case, it may be necessary to mask the outer sides of the left and right photographic films at the time of mounting to correct the parallax as in the conventional case.

FIG. 18 shows the screen layout of the stereo camera proposed in view of the characteristics of the stereo camera requiring parallax correction at the time of mounting as described above, because the edge of the screen of the film F is masked at the time of mounting. The exposure screen is arranged so that a gap is not provided 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-described embodiment, and for example, the viewfinder structure of the stereo camera shown in FIGS. 7 to 11 is applied to the stereo camera 51 of FIG. Various modifications are possible within the technical scope, and it goes without saying that the present invention covers those modifications.

[0040]

As described above in detail, in the stereo camera of the present invention, since the screens synthesized by connecting 1/2 of the left and right screens can be observed with one viewfinder, the two cameras can be viewed through two viewfinders. Visibility is better than that of
Excellent operability. In addition, the conventional penta prism
The manufacturing cost of the viewfinder can be reduced compared to a stereo camera equipped with a single unit, which can contribute to the cost reduction of the reflex type stereo camera.

Further, in the stereo camera according to the second aspect, whether the parallax correction and the focus adjustment can be passed or failed can be judged by the finder image, and the image can be taken in a state where the screen loss can be suppressed and the optimum stereo effect can be exhibited. it can.

[Brief description of drawings]

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

2A and 2B show a prism, in which FIG. 2A is a rear view, FIG. 2B is a plan view, FIG. 2C is a front view, FIG. 2D is a bottom view, and FIG. Figure (f) is a side view.

FIG. 3 is an explanatory diagram showing a relationship between a prism size and a focusing screen pitch.

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

FIG. 5 shows another embodiment of the prism, (a) is a plan view, (b) is a front view, (c) is a bottom view, (d) is a rear view, and (e) is A of (b). -A line arrow view, (f) is a side view.

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

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

8 shows the prism of the stereo camera shown in FIG.
(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 the line AA of (b),
(F) is a side view.

9 is an explanatory diagram showing the arrangement of prisms and reflex mirrors of the stereo camera shown in FIG.

10 is a perspective view showing the arrangement of prisms and reflex mirrors of the stereo camera shown in FIG.

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

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

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

FIG. 14 is an explanatory view of a focus adjusting mechanism and a center-to-center distance adjusting 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 center-to-center distance adjustment of the lens.

16 (a) is an explanatory diagram showing a viewfinder image of the subject, and FIGS.

17 (a), (b) and (c) are explanatory views showing finder images of a subject, respectively.

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

[Explanation of symbols]

 1 Stereo camera 3 Slide frame 4,5 Lens 6 Focus adjustment dial 9,10 Focus 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)

[Claims] 1. An optical system of a single-lens reflex camera consisting of a lens, a reflex mirror and a prism is mounted on the left and right of one camera body, and the incident images of the left and right lenses are transmitted through the reflex mirror and the prism. In a reflex type stereo camera capable of observing, the outside of the photographing range of each of the left and right lenses is 1/2
It is characterized in that it has a composite prism that symmetrically flips the screen of left and right to synthesize one erect image, and that the outer half of the shooting range of the left and right lenses can be observed with a single eye. Stereo camera to do. 2. The center-to-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-to-center distance adjustment mechanism of the lenses, and the photographing range of the left and right lenses at the focusing distance Claim 1 formed so as to always match
The stereo camera as described.