JPH02171739A - Stereo camera - Google Patents

Abstract

PURPOSE:To always take a focused picture even in stereo or normal photographing by providing a compensating means which compensates a change in the length of an optical path, which is caused by the insertion and retreat of filters into or from the optical path. CONSTITUTION:The camera is provided with the compensating means which compensates a change in the length of the optical path, which is caused by the insertion or retreat of the 1st and 2nd filters 3a and 3b into or from the optical path. By switching a photographing mode, the 1st and 2nd filters 3a and 3b are inserted into the optical path or retreated from the optical path, however, the change due to the insertion and retreat can be compensated by a change in the feeding amount of a photographing lens or the use of a transparent compensating plate; therefore defocus never occurs in any photographing modes. Consequently, a focused picture can be taken in the stereo and normal photographing modes.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a camera capable of taking stereo photographs.

[Conventional technology]

Stereo photography using anaglyphic printing is already known. This method involves making a plate by superimposing two photographs viewed from different viewpoints, using ink (hereinafter referred to as warm color ink) that blocks the short wavelength range of visible light for one photograph, and for the other photograph. Photography is a method of printing and reproducing an image on a sheet of white paper using ink that blocks the long wavelength range of visible light (hereinafter referred to as cold ink). When making a plate,
The amount of shift between the two photographs is set so that the images of the main subject are completely superimposed.

This print is viewed using glasses with two color filters. One of the color filters is a filter that transmits a long wavelength range of visible light (hereinafter referred to as a warm color filter), and the other is a filter that transmits a short wavelength range of visible light (hereinafter referred to as a cold color filter). The part with the cool color ink is
Since the degree of reflection of light in the long wavelength range is limited depending on the density, differences in density can be recognized when observed through a warm color filter. However, no matter what the density of the warm color ink, it is impossible to limit the degree of reflection of light in the long wavelength range, so if you observe it through a warm color filter, you will not be able to recognize the difference in density.
It is observed to be equivalent to no ink being applied. Therefore, the eye observing through the warm color filter only recognizes images printed with cool color ink, and does not recognize images printed with warm color ink. Similarly, the eye viewing through a cool color filter only perceives images printed with warm color inks and not images printed with cool color inks.

In this way, the observer can separate and observe the images of the two photographs printed one on top of the other again, even if the two photographs were taken from different viewpoints. For example, stereoscopic observation is possible.

Compared to the method of viewing two independent photographs using Pure, the advantage of stereo photography using anaglyphic printing is that the two photographs are printed one on top of the other, so there is no limit to the observation distance when viewing. Moreover, there is no need for a magnifying lens, and stereo images can be viewed from any viewing angle and distance by simply wearing glasses with two color filters.

[Problem to be solved by the invention]

By the way, in order to create a stereo photo using the conventional anaglyphic method, two photos are taken from different viewpoints,
These images had to be layered and composited, making the shooting and subsequent processing complicated.

The invention of this application aims to solve the above-mentioned problems and provide a camera that can easily take stereo photographs and also take ordinary photographs. To provide a camera that can always take in-focus photographs even when taking pictures.

[Means to solve the problem]

In order to solve the above problems, the stereo camera of the present invention includes a first filter disposed in the optical path of the photographic lens on the left side with respect to the optical axis, and a second filter having spectral transmission characteristics different from those of the first filter. In the stereo camera, the stereo camera is equipped with a switching means capable of switching between a stereoscopic photographic mode arranged to the right with respect to the optical axis and a normal photographic mode in which the first and second filters are retracted from the optical path. The present invention is also characterized by comprising compensation means for compensating for changes in the optical path length caused by insertion and withdrawal of the second filter into the optical path.

As a compensation means, when equipped with an automatic focus adjustment device that advances the photographic lens according to the subject distance, the amount of extension of the photographic lens is changed according to the insertion and withdrawal of the first and second filters into the optical path. to compensate for changes in optical path length. Also, instead of changing the amount of extension of the photographic lens,
A transparent compensator with an optical path length equivalent to that of the first and second filters is provided, and when the first and second filters are retracted from the optical path, the transparent compensator is inserted into the optical path to compensate for changes in the optical path length. You can do it like this.

[For production]

By switching the photographing mode, the first and second filters are inserted into the optical path of the photographing lens, and are also retracted out of the optical path.The change in the optical path length caused by this can be corrected by changing the amount of extension of the photographing lens, or by changing the length of the photographic lens. Since compensation is performed using a compensation plate, no out-of-focus occurs in any shooting mode.

〔Example〕

Examples of the present invention will be described below.

[Basic configuration of stereo camera]

First, the basic configuration of the stereo camera of the present invention will be explained. FIG. 1 is a diagram showing the basic configuration of a camera, where l is a photographing lens, 2 is an aperture, and 3 is a light flux limiting plate. 3a, 3
b is a pair of wavelength selective transmission filters, one of which is set to transmit a short wavelength range, and the other is set to transmit a long wavelength range, with a certain boundary wavelength of visible light as the boundary. The transmission characteristics of this pair of wavelength selective transmission filters are shown in FIG. 2. As shown in FIG. 2, the entire visible light region is covered by the two filters 3a and 3b.

Furthermore, near the boundary wavelength, the transmission characteristics of the two filters 3a and 3b overlap. 3a of the luminous flux limiting plate,
Locations other than 3b are formed so as not to transmit light.

The object scene image is projected onto a photographing color film 4 by a photographing lens 1 through an aperture of an aperture 2, a light flux limiting plate 30, and wavelength selective transmission filters 3a, 3bk. The projected light beam is exposed onto a film by a known shutter (not shown) and recorded as a latent image.

[Photography optical system]

Next, a photographing optical system for forming a subject image on a photographic film will be explained. FIG. 3 is a plan sectional view of the camera installed facing the field of view, in which reference numerals 1, 2, 3 and 4 indicate the same members as in FIG. 1, and 5 indicates a dark box. In the illustrated state, the object point B on the field side is in focus. Therefore, the image B' of the object point B is formed as a point on the photographic film 4. The situation is shown in FIG. 3(a).

At this time, the image A' of object point A, which is farther away than object point B, is formed on the side closer to the field of view than the photographic film 4.

An image C' of an object point C, which is closer than a round object point B, is formed on the side of the photographic film 4 that is far from the field of view. The situation is shown in FIG. 3(b).

Exposure is performed by a shutter (not shown) according to the photographing operation of the photographer, and the images of object points A, B, and C are recorded on the photographic color film 4 as an inverted latent image. FIG. 4 shows the latent image viewed from the direction indicated by arrow S in FIG. 3(b). Ai, Bi.

Ci are latent images of object points A, B, and C, respectively. The shaded area is an image recorded by the light beam that has passed through the wavelength selective transmission filter 3a, and the multi-point area has passed through the wavelength selective transmission filter 3b. Bi is recorded as a point image by focusing. Ai is recorded as a pair of defocused circular images, with the image passing through the filter 3a being separated to the right and the image passing through the filter 3b being separated to the left. On the other hand, Ci is recorded as a pair of day-focused circular images, with the image transmitted through the filter 3a being separated to the left and the image passing through the filter 3b being separated to the right.

Next, two examples of preferred combinations of materials used for the pair of wavelength selective transmission filters 3at3b will be explained.

In the first example, the filter 3a is a filter that selectively transmits light in a band that sensitizes the red-sensitive layer of a color film, such as Kodak Wratten 7 Ilta 425, A.
24 or the like, and the filter 3b is a filter that selectively transmits light in the band that sensitizes the green and blue sensitive layers of the color film, for example, &4 of the product name Kodak Ratten Filter.
4A-Ni64 etc. are used. In a color film photographed using a pair of wavelength-selective transmission filters in this combination, a latent image is recorded by the light beam transmitted through 3a in the red-sensitive layer, and a latent image is recorded by the light beam transmitted through 3b in the green-sensitive layer and the blue-sensitive layer. A latent image created by the light beam is recorded.

In the second example, a filter that selectively transmits light in a band that exposes the red-sensitive layer and the green-sensitive layer of the color film, such as Kodak Ratten Filter Noni 12 (trade name), is used as the filter 3a, and the filter 3b is the Toshite color film. A filter that selectively transmits light in a band that sensitizes the blue-sensitive layer, such as the flat 47 of Kodak Ratten Filter (trade name), is used. In a color film photographed using this combination of a pair of wavelength-selective transmission filters, a latent image is recorded in the red-sensitive layer and the green-sensitive layer by the light beam transmitted through 3a.
A latent image is recorded in the blue-sensitive layer by the light beam that has passed through 3b.

Therefore, both of the above two embodiments have two different viewpoints.
Although the pair of field images observed by the two entrance pupils 3a and 3b are superimposed on one screen, they are recorded on independent media without any interference with each other. Become. In other words, the left and right channels will be recorded without crosstalk.

[Glasses for viewing 3D images]

A means for viewing a photographed image as a three-dimensional image will be explained. FIG. 6 shows viewing glasses for viewing photographed images, and includes a pair of wavelength selective transmitting members 11a and 11b for both eyes, and a wavelength selective transmitting member 11a for the left eye. Light in a band that can pass through the wavelength selective transmission filter 3a is sufficiently transmitted, and light in a band that can pass through the wavelength selective transmission filter 3b is almost completely blocked.

Further, the wavelength selective transmission member 11b for the right eye has characteristics such that it sufficiently transmits light in a band that can pass through the wavelength selective transmission filter 3b, and almost completely blocks light in a band that can pass through the wavelength selective transmission filter 3a. is set.

Therefore, the image that can be observed through the wavelength selective transmission member 11a indicated by diagonal lines is an image generated only by the light transmitted through the wavelength selective transmission filter 3a, that is, the image indicated by diagonal lines. Furthermore, the image that can be observed through the wavelength selective transmission member 11b shown by the multi-dot coating is an image generated only by the light that has passed through the wavelength selective transmission filter 3b, that is, the image shown by the multi-dot coating.

FIG. 5 is a photograph of the film on which the latent image shown in FIG. 4 is recorded and developed into an erect image, and FIG. 7 shows how this is viewed through the glasses shown in FIG. 6. In the figure, when an observer observes the object point images Ai and Bi+Ci on the photograph with both eyes, the apparent object point images are points As,
Generated at the Bs and Cs positions. As appears to be set back from the plane of the photograph, Bs appears to be on the same plane as the plane of the photograph, and C
s appears to stand out from the surface of the photo. In this way, the viewer can observe the photograph as a three-dimensional image according to the depth order of the field. In particular, since the main subject image is usually in focus, there is no image shift as shown by the object point image Bs, making it easy to appreciate.

FIG. 8 shows an example of a photograph obtained by photographing an actual scene. When viewing this photo through the glasses shown in Figure 6, the mechanism is the same as in Figure 7: the trees appear to be receding from the plane of the photo, the main subject appears to be on the same plane as the plane of the photo, and the shrubs appear to be on the same plane as the plane of the photo. It appears to stand out from the surface of the photo. In this way, according to the depth of field order.

The viewer can observe the photograph as a three-dimensional image.Next, preferred combinations of the wavelength-selective transmission members 11a and llb will be described for the two preferred combinations of the wavelength-selective transmission filters described above. .

A preferred combination for the first example is:

11a is a filter that blocks light in a band whose transmission and non-transmission can be controlled by the color development of the blue-sensitive yellow coloring layer and the green-sensitive magenta coloring layer of a color photograph, ie, a red filter, such as A 25 and A of the trade name Kodak Wratten filter.
26, Ifa 29, etc.

As 11b, a filter that blocks light in a band whose transmission and non-transmission can be controlled by the color development of the red-sensitive cyan coloring layer of a color photograph, that is, a blue-green filter, such as A 44A and A 44 of the trade name Kodak Ratten Filter, is used. be. A viewer who wears glasses using this combination of a pair of wavelength-selective transmitting members sees an image generated by the blue-yellow coloring layer and the green-ishing magenta coloring layer with their left eye.

The right eye recognizes the image generated by the red-sensitive cyan coloring layer, respectively.

A preferred combination for the second example is:

As 11a, a filter that blocks light in a band whose transmission and non-transmission can be controlled according to the color development of the blue-ish yellow coloring layer of a color photograph, that is, an orange filter, such as Kodak Ratten Filter 412, Al 5° Ya 16, etc. is used. , 11
As for b, a filter that blocks light in a band whose transmission and non-transmission can be controlled depending on the color development of the green-sensitive magenta coloring layer and the red-sensitive cyan coloring layer of a color photograph, ie, a back-color filter, such as the product name Kodak Ratten Filter, 47. 47B or the like. A viewer who wears glasses that use this combination of a pair of wavelength-selective transmitting members will see an image generated by the blue-sensitive yellow coloring layer with the left eye, and a green-sensitive magenta coloring layer and the red-sensitive cyan coloring layer with the right eye. Recognize each generated image.

Therefore, by using either of the glasses of the above two embodiments, the viewer can see images recorded using the wavelength-selective transmission filter on each independent medium on the color film without any interference with each other. Each image can be observed separately. In other words, images of both left and right channels can be observed without crosstalk.

[Quality and color of photos seen without viewing glasses] Next,
I will discuss the quality and color of this photo when viewed without viewing glasses. The main subject, that is, the subject that is in focus, is reproduced in faithful colors without any color shift as described above, so there is no problem in viewing the subject.

When a subject is out of focus, a shift occurs between the warm color image and the cool color image. The appearance of this color shift regarding the point image is shown as E in FIG. Assuming the configuration shown in FIG. 1, from the relationship between the size of the effective diameter of the photographic lens 1 and the size of the wavelength selective transmission filters 3a and 3b, the day-focused circle of confusion as a characteristic of the photographic lens alone is The statue is
In contrast to the shape EK, the shape becomes DK. That is, the images E of the two circles of confusion separated into warm colors and cold colors are included in the confusion circle image of the photographing lens itself. Therefore 1
It can be seen that the size of the color shift does not exceed the size of the circle of confusion caused by the day focus of the photographic lens itself. In this way, in photographs taken according to the present invention, the subject for which a one-color shift is observed is an out-of-focus subject, and the amount of color shift naturally occurs due to the individual characteristics of the photographic lens. Since the image is within the range of out-of-focus, even if viewed directly with the naked eye, it will not appear as a clear double image and can be viewed as a normal color photograph.

Therefore, when the photograph obtained according to the present invention is viewed without viewing glasses, the color reproducibility of the main subject and the subjects equidistant therefrom can be ensured, and the color reproducibility is comparable to that of ordinary color photographs. For other subjects, you can clearly see the colors even though they are naturally out of focus.

[Switching between stereoscopic photography mode and normal photography mode] The stereo camera of the present invention, the basic configuration of which is shown in Figure 1, is configured to be switchable between stereoscopic photography mode and normal photography mode. Ru.

That is, the light flux limiting plate 3 is configured to be rotatable around the rotation axis 3c, and by operating an operating member (not shown) that engages with a groove 3d provided at one end of the light flux limiting plate 3 from the outside, the light flux limiting plate 3 can be rotated. 3 into the photographing optical path.

Alternatively, it is possible to switch between stereoscopic photography mode and normal photography mode by withdrawing from the photographing optical path.

In the stereoscopic photography mode, the light flux limiting plate 3 enters the photographing optical path, so the amount of exposure incident on the film surface is smaller than in the normal photography mode. Therefore.

Depending on the mode, the sensitivity of the photometric circuit of the camera's automatic exposure control mechanism or the amount of light incident on the photometric element is adjusted to ensure that the optimal amount of exposure is always obtained. FIG. 10 shows the configuration for this purpose, and FIG. 1O (a) shows the light flux limiting plate 3.
When K is withdrawn from the photographing optical path, the protrusion 3e provided at one end of the light flux limiting plate 3 closes the switch 6, thereby reducing the amplification gain. switch to lower the sensitivity of the photometry circuit.

FIG. 10(b) shows that when the luminous flux limiting plate 3 is positioned on the photographing optical path, the transmitted light amount reducing filter 3f provided on a part of the luminous flux limiting plate 3 is positioned in front of the external light type photometric sensor (not shown), and the luminous flux is limited. When the plate 3 retreats from the photographing optical path, the filter 3f
It also moves the camera away from the front of the photometering unit. Thereby, the amount of light incident on the photometric element can be adjusted, and the optimum amount of exposure can always be obtained.

In the automatic exposure control mechanism used in the stereo camera of the present invention, when the stereoscopic photography mode is selected, the open aperture, which is advantageous in securing the baseline length between the two entrance pupils, is set to a wide range of field brightness. 1 When the normal photo mode is selected, an intermediate aperture that is advantageous in securing depth of field is selected for a wide range of field brightness.
It's good to do that.

[Wavelength selection filter and aperture blade shape]

Since the stereo camera of the present invention has two wavelength-selective transmission filters 3a and 3b, if the relationship between the contours of these filters and the contours of the aperture blades is not appropriate, it will be difficult to view photographs stereoscopically using glasses. Sometimes it looks unnatural.

FIGS. 11(a), 11(b), and 11(c) are examples showing the contour shape of a filter and the contour shape of an aperture blade suitable for this, respectively. In the figure, l is a photographing lens, 21a/2
1b, 22a/22b, 23a/23b
are each a pair of wavelength selective transmission filters, 25a
/25b, 26a/26b, 27a/27
Each b indicates a pair of aperture blades. In these examples, regardless of the aperture value, two colors, a cool color and a warm color, formed by the outline of the wavelength selective transmission filter and the outline of the aperture blade are used. Since the contours of the two exit pupils are congruent and have the same posture, when viewing a photo stereoscopically using glasses, the contours of the object point images are equal on the left and right, allowing natural stereoscopic viewing.

In addition, in the example shown in FIG. 11, a wavelength selective transmission filter for short wavelengths (hereinafter referred to as a cold color filter) and a wavelength selective transmission filter for long wavelengths (hereinafter referred to as a warm color filter) are used that transmit the same amount of light. .

If the transmittance, that is, the amount of transmitted light, of the cold color filter and the warm color filter used in the light flux limiting plate are different, the main subject in focus will not have a natural color.

For example, if the transmittance of the cool color filter and the warm color filter used is 2:3, the main subject will be photographed with a reddish color, and if you look at the photo without glasses, the main subject will appear redder than the actual color. take on flavor.

Therefore, as a countermeasure to this problem, the area of the filter is changed to correct the difference in transmittance of the filter, and the amounts of transmitted light of the cold color filter and the warm color filter are made equal.

Figures 12(a) to 12(d) are examples of light flux limiting plates having filters that equalize the amount of transmitted light using the method described above, where CF indicates a cold color filter and WF indicates a warm color filter. ing. FIG. 5A shows an example in which the cool color filter CF and the warm color filter WF have the same transmittance, and the filter area ratio is l:1. Figure (b) shows a case where the transmittance of the cool color filter CF and the warm color filter WF is 2:3, and the central angle is divided into 216° and 144° so that the filter area is 3:2 and the amount of transmitted light is equal. This is an example. In this way, if the area of the cool color and warm color filters is set to the reciprocal of the transmittance of each filter, the amount of transmitted light of both filters can be made equal. When adjusting the amount of light using a circular diaphragm, the amount of light transmitted through both filters will vary depending on the aperture υ value, as shown in Figure 12(d).
As shown in , it is recommended to divide the diaphragm in the radial direction around the same point as the center of the diaphragm.By dealing with 0 or more, even if the transmittance of the cold color filter and the warm color filter are different, the amount of transmitted light of both filters will be equal, and the natural It becomes possible to reproduce colors.

Furthermore, three filters may be used to improve the color rendering of the photograph. The light flux limiting plate shown in FIG. 13 is formed of band-shaped filters of three colors: red, green, and blue.The central filter 33c is green, the left filter 33a is red, and the filter 33a on the left is red.
The right filter 33b is blue. The transmission wavelength range of each filter is set according to the wavelength range to which the emulsion of the color film sensitive to red, green, and blue is sensitive. When using this light flux limiting plate, it is possible to improve the color balance of the photograph by selecting a filter that is suitable for the emulsion sensitive wavelength range of the color film.

Even with a light flux limiting plate that uses the three-color filter mentioned above, the color of the main subject will differ from the natural color due to the difference in the amount of transmitted light due to the difference in the transmittance of the filters.To deal with this, in the case of a cold color filter and a warm color filter, Similarly, by setting the area of each filter to the reciprocal of the transmittance of each filter, the amount of transmitted light can be made equal. Fig. 14 is an example of this, and Fig. 14 (a) shows the case where the transmittance is equal;
An example in which the central angle is set to 1206 is shown in the same figure (b).
is the case where the transmittance is blue, green, red = 2 = 3:4, and the central angle is 1/2: 1/3: 1/4 = 166°: 111
In this example, the angle is set to 6-83°. In addition, cold color filter C
Similarly to the case where F and the warm color filter WF are used, division is performed along a vertical line (see FIG. 14(c)), or in the radial direction centered at the same point as the center of the diaphragm (see FIG. 14(c)). figure(
An example of a filter that facilitates focusing in the case of a single-lens reflex camera is shown in FIG. 15. In this embodiment, the light flux limiting plate 35
Three adjacent strip-shaped transparent members are provided on the top. The central transmitting member 35c is colorless and transparent, and the colors of the left and right transmitting members 35a and 35b are respectively equal to the colors of the filters 3a and 3b of the light flux limiting plate 3 shown in FIG. As the focus plate 36 of a single-lens reflex camera using this light flux limiting plate, there is used one in which two micro-split prisms are formed in the center of the screen divided into right and left sides, as shown in FIG. And this micro split prism 37.
38 are tilted in opposite directions in the vertical direction of one screen.

The portions through which the light beams passing through the two micro-split prisms 37 and 38 and entering the photographer's eyes are transmitted through the light beam limiting plate are portions 35g on the central transmission member 35c, respectively.
35h, the photographer observes the light flux passing through the colorless and transparent member through the micro-split prisms 37 and 38.

Focusing can be performed easily.

[Aperture and shutter mechanism]

It was previously stated that in the stereo camera of the present invention, it is advantageous to select the wide aperture in the stereoscopic photography mode and to select the intermediate aperture in the normal photography mode, but the aperture and shutter mechanism described below is advantageous. It is suitable for such requirements.

FIG. 17 shows the diaphragm/shutter mechanism in the three-dimensional photographic mode. In FIG. 17, 1 is a photographing lens, and 3 is a light flux limiting plate placed behind the photographic lens 1. 42
Reference numerals a and 42b designate a pair of shutter blades that also serve as a diaphragm and are arranged close to the light flux limiting plate, and are configured to be rotatable about a support shaft 42e. The shutter blade has the shape shown in FIG. 18, and is provided with cam slots 42c and 42d. Reference numeral 46 denotes a reciprocating lever, which is configured to be rotatable around a pin 46b, and is urged by a spring 47 to rotate counterclockwise. A pin 46a is provided at one end of the reciprocating lever 46, and the pin 46a is a shutter blade 42a.

42b is engaged with cam slots 42c and 42d.

Further, the other end of the reciprocating lever 46 is provided with a pawl 46a and a sector gear 46c.
is a locking lever, which is rotatable when the pin 51a is turned;
A locking pawl 51c at one end engages with a pawl 46d of the reciprocating lever. An ankle switching lever 44 is rotatable around a pin 44b, and is urged by a spring 55 to rotate counterclockwise. One end 44a of the ankle switching lever 44 comes into contact with a protrusion 43e at one end of the light flux limiting plate 43,
It was. An ankle 45 is provided at the other end and meshes with the triangular tooth portion 53b of the slow gear 53. The small gear 53a of the slow gear 53 is the sector gear 46c on the reciprocating lever 46.
It meshes with. Reference numeral 48 denotes a return lever, which is rotatable as the pin 46b is rotated, and is urged by a spring 49 to rotate clockwise. Further, the return lever 48 is provided with a pin 48c that can come into contact with the side surface of the reciprocating lever 46, and a claw 48b is provided at the end. 54 is a locking lever, which is freely rotatable in the oob direction of the pin 154a;
One end of the locking pawl 54c engages with the pawl 48b of the return lever.

If the stereoscopic photography mode is selected and the light flux limiting plate 3 is entered into the photographing optical path, the state shown in FIG. 17 will be obtained. When the shutter is released, one end 51b of the locking lever 51 is pushed in the direction of arrow Y1.

The locking pawl 51c is removed from the pawl 46d of the reciprocating lever 46. As a result, the reciprocating lever 46 rapidly rotates counterclockwise due to the biasing force of the spring 47, and the pin 46a moves the shutter blade 42a to the right in the figure.

An exposure opening is formed by rotating the shutter blade 42b to the left, and the film is exposed. When a predetermined exposure time has elapsed, one end 54 of the locking lever 54 is activated by an operation member (not shown).
b is pushed in the direction of arrow Y2.

The locking claw 54c and the claw 48b of the return lever 48 are disengaged. As a result, the return lever 48 rapidly rotates clockwise due to the biasing force of the spring 49, and the pin 48c contacts the side surface of the reciprocating lever 46 to rotate the reciprocating lever 46 clockwise. As a result, shutter blades 42a and 42b
The end rotates in the opposite direction to close the exposure opening.

Changes in the exposure aperture due to the above operations are shown in FIG. 19(a). Track 0 #JAt indicates the case of short exposure;
shows the case of long exposure, but as is clear from Figure 1,
In either case, the aperture value is the open aperture value.

In addition, the songs indicated by the dashed line! IAI' and A2' are obtained when the light flux limiting plate 43 is inserted into the photographing optical path. The effective waveform of the exposure aperture is shown. As is clear from the figure,
The effective value of the light flux limiting plate 43 and the aperture are decreasing.

Next, when the normal photography mode is selected and the light flux limiting plate 43 is retracted out of the photographing optical path, the engagement between the protrusion 43e provided at one end of the light flux limiting plate 43 and the one end 44a of the ankle switching lever 44 is released. The ankle switching lever 44 has a spring 55
Due to the biasing force υ, it rotates counterclockwise and comes into contact with the pin 56. Koshi K! , jri 77 gear 45 is slow gear 53
meshes with the triangular tooth portion 53b. When the shutter is released in this state, one end 51b of the locking lever 51 is pushed in the direction of the arrow, and the locking pawl 51c engages the pawl 4 of the reciprocating lever 46.
It comes off from 6d. As a result, the reciprocating lever 46
It rotates υ counterclockwise due to the urging force of 7, but at this time,
A braking force is applied to the slow gear 53 by the pallet wheel 45, causing it to rotate slowly. Small gear 53 coaxial with slow gear 53
Since a is meshed with the sector gear 46c, the reciprocating lever also rotates counterclockwise, and the shutter blade 42a
, 42b are also slowly opened to perform exposure.

When the predetermined exposure time has elapsed, one end 54 of the locking lever 54
b is pushed in the direction of the arrow, the return lever 48 is unlocked, the return lever 48 is rotated clockwise by the biasing force of the spring 49, and the pin 48c rotates the reciprocating lever 46 clockwise. At this time, the reciprocating lever 46 slowly rotates clockwise by the action of the slow gear 53 as before, the shutter blades 42a and 42b also slowly close, and the exposure ends.

The 0 curve B1 shown in FIG. 19(b) showing the change in the exposure aperture due to the above operation shows the case where the exposure amount is equal to the curve All shown in FIG. 19(a), and the curve B2 shown in FIG.
This shows the case where an exposure amount equal to the curve A2/ shown in a) is given. In normal photo mode.

Since the light flux limiting plate is retracted outside the photographing optical path, the transmittance is higher than in stereoscopic photography mode, where the light flux restricting plate is in the photographing optical path, even if the aperture diameter is the same. Therefore, the effective effectiveness including transmittance is The aperture diameter is large.

According to the above-mentioned shutter, in the case of stereoscopic photography mode, it is possible to control exposure by always using an open aperture for a wide range of subject brightness values, so the baseline length between the two entrance pupils is always ensured. It is possible to take photographs with excellent three-dimensional effects, and the reduction in the effective aperture diameter caused by the use of the light flux limiting plate can be automatically corrected by changing the exposure waveform of the shutter to a trapezoidal waveform. As a result, it is possible to take both a stereoscopic photograph and a normal photograph with the same exposure time for a subject having the same brightness without using any special correction means.

FIG. 20 shows the temporal change diagram A1 of the diaphragm aperture shown in FIG. 19. A2, B1. The relationship between shutter speed and aperture υ value with respect to B2 and exposure value Ev is shown.

As is clear from the figure, the diagrams AI, A2 are different from the diagrams 81.A2 for the same exposure value Ev. B2 and other lenses are also configured to have a larger aperture diameter. In addition, in the figure, the shutter speed scale is different in the case of line A, A2 and the case of line B, B2. Figures A and A2 have a larger amount of exposure. For example, for the subject shown in Figure 1 (appropriate exposure amount Ev), [1 Figure 81 and B2 have an aperture value two steps larger than those in Figure A1 and A2, whereas the shutter speed is Then 1 stage (A,, 1/25 for A2
Although it is 0 seconds, line diagram B1. In B2, it is only 1/125 seconds). Therefore, in the example shown in Figure 20, for the same subject, stereo photography mode (lines A1, A2) is one step overexposed than normal photography mode (lines B0, B2). The shutter is controlled so that

Since this overexposure is reduced by the light flux limiting plate 43, an appropriate amount of exposure can be obtained in either the normal photo mode or the stereo photo mode.

[Correction for changes in optical path length]

When a light flux limiting plate is inserted into the optical path of the photographing optical system, the optical path length becomes longer than when it is not inserted. For this reason, TTL
For non-distance-measuring cameras, with and without a light flux limiting plate inserted.

It becomes necessary to correct the amount of extension of the photographic lens based on the measured distance information to the subject.

The configuration for this purpose will be explained based on FIGS. 21 to 24.

FIG. 21 is a plan sectional view of a stereo camera embodying the present invention viewed from above, FIG. 22 is an enlarged sectional view of the vicinity of the light flux limiting plate 3, and FIG. lens, 2 is a shutter that also serves as an aperture, 3 is a light flux limiting plate,
B4 is a switch for detecting that the light flux limiting plate 3 is inserted into the optical path of the photographing optical system, 71 is a gear for driving the light flux limiting plate, and 64 is a light flux limiting plate driving motor.

A sector gear 72 is provided on the extension of the light flux limiting plate 3 and meshes with a gear 71 attached to the shaft of the drive motor 64, so that the light flux limiting plate 3 rotates around the shaft 3c and is inserted into the photographing optical path. , and evacuate from the photographing optical path. At this time, the protrusion 73 provided on a part of the light flux limiting plate 3 turns the switch S4 ON/O.
Operate to FF.

FIG. 24 is a block diagram of the camera control circuit.
F)62. In addition to controlling the shutter mechanism 63, the light flux limiting plate drive motor 64, lens feeding motor 65. It also controls the film winding motor 66 and outputs an imprint signal to the data imprint device 67 on the camera back cover. The microcontroller 60 has a main switch So
, photometric switch S1. Shirt release switch S2.
A photographing mode selection switch S3° for selecting between the stereo photographic mode and the normal photographic mode and a switch S4 for indicating the insertion state of the light flux limiting plate 3 are connected, and necessary control information is input.

The second sequence of camera control operations by the microcomputer 60
This will be explained based on the flowcharts shown in FIGS. 5 and 26.

First, the flowchart shown in FIG. 25 will be explained.

When the power battery is inserted into the camera, the microcomputer 60 turns on the main switch S. Wait for it to turn on (step PI)
Main switch S. When turned on, the microcomputer 60
determines whether or not it is the stereo photography mode based on the state of the switch S3 (step P2). When it is determined that the switch S3 is ON and the stereo photography mode is selected, the microcomputer 6
0 drives the light flux limiting plate drive motor 64 to move the light flux limiting plate 3
is inserted into the optical path (step P3). On the other hand, if it is determined that the switch S3 is OFF and the mode is normal photography mode, the microcomputer 60 drives the light flux limiting plate drive motor 64 to retract the light flux limiting plate 3 from the optical path (step P4).

When the insertion/retraction of the light flux limiting plate 3 is completed, the microcomputer 60
determines the state of the photometry switch S1 (Stella';'P
5) When it is determined that the photometry switch S1 is turned on by pressing down the shirt release button one step,
The microcomputer 60 performs operations starting from step P6, which will be described later. On the other hand, if it is determined that the shirt release button has not been pressed down yet and the photometry switch S1 is OFF, the microcomputer 60 returns to step PI and repeats the operations υ1 and above.

If it is determined in step P5 that the photometric switch S1 is ON, the microcomputer 60 causes the photometric means 61 to perform a photometric operation (step P6).

Thereafter, the microcomputer 60 determines whether or not the light flux limiting plate 3 is inserted into the optical path based on the state of the switch S4 (step P7). When switch S4 is ON, microcomputer 6
0 determines that the light flux limiting plate 3 is inserted in the optical path,
In step P8, the distance measuring means 62 is caused to perform a distance measuring operation. Thereafter, a correction calculation for the lens extension amount is performed (step P9). Regarding the correction amount, a value determined in advance may be stored in the ROM. In addition.

In this step P9, the exposure time and aperture may be corrected based on the photometric value obtained in step P6 so that proper exposure is obtained when the light flux limiting plate 3 is inserted. If it is determined in step P7 that the switch S4 is OFF, the microcomputer 60 causes the distance measuring means 62 to perform a distance measuring operation in step PIO.

When the distance measurement operation and correction are completed, the microcomputer 60 determines whether the shirt release switch S2 is ON (
Step P11) When the shirt release button is pressed down two steps and the switch S2 is turned on, the microcomputer executes a photographing operation (steps P12 to P15), which will be described later. When determining that the shirt release switch S2 is OFF, the microcomputer 60 determines whether the photometry switch S1 is ON (step P17). When the microcomputer 60 determines that the photometric switch S is ON, the microcomputer 60 returns to the step pH operation, and when it determines that the photometric switch S1 is OFF, the process returns to step P1. In other words, by holding the shirt release button down one step, a so-called crown lock or M lock is performed.

In step P11, the shirt release switch S
2 is ON, the microcomputer controls the lens advancing motor 65 based on the ranging data corrected in step P9 or obtained in step PLO to focus the photographing lens 1 (step PLO). P12)
. Then, the microcomputer 60 controls the shutter mechanism 63 according to the photometric data obtained in step P6 and the presence or absence of the light flux limiting plate 3, and performs an exposure operation (step P13).
. After completing the exposure operation, the microcomputer 60 controls the film winding motor 66 to wind the film (step P).
14) The lens is retracted by controlling the lens retracting motor 65 (step P15). Thereafter, the microcomputer 60 waits until the photometry switch S1 is turned OFF, and the shirt release button is returned to its original state (step P16).
), return to step PI. As a result, even if the photographer accidentally presses the shirt release button and then releases it, the photographing operation is performed only once, so there is no need to waste film. Note that the camera can be switched between continuous shooting mode and single frame shooting mode, and step P15.1!
A step for determining the shooting mode is provided between step P16 and step P16 when the continuous shooting mode is selected.
5 (or step P11), and in the single-frame shooting mode, the process may proceed to step P16.

In the above embodiment, the amount of extension of the photographic lens is corrected (
Although the photographing optical path length is corrected by step P9), the photographing optical path length may also be corrected as described below.

FIG. 26 is a flowchart showing the sequence of control operations for correcting the optical path length, and includes step P21.
~P23, P25, P26, P31~37
The processing in steps P1 to P in FIG.
3.P5. P6. Since this is the same as the processing in pH-PI3, the explanation will be omitted, and the differences will be explained below.

First, when it is determined in step P22 that the mode is not stereo photography mode, the process proceeds to step P24, where an optical path length compensating plate made of a transparent material and having an optical path length equal to that of the first and second filters is inserted. In this case, unlike the process shown in FIG. 25, there is no need to correct the lens extension amount, so step P7 in the flowchart of FIG. P8. P
The process shown in 9°PLO is omitted, and photometry (step P2
6) and distance measurement (step P28), the process moves to determining whether the shirt release switch S2 is ON (step P31).

FIG. 27 shows the light flux limiting plate 3 and its driving mechanism in this case. As shown in the figure, the light flux limiting plate 3 includes a filter 3a,
In addition to filter 3b, an optical path length compensating plate 3 made of a colorless transparent material and having an optical path length equivalent to that of filters 3a and 3b is provided at a position apart from filters 3a and 3b.
An X is provided.

The light flux limiting plate 3 is provided with a fan-shaped gear 72 which meshes with a light flux limiting plate driving gear 71 and is driven by a motor. Also.

73 is a protrusion, and S4 is a switch that detects when the light flux limiting plate enters the photographing optical path.The drive mechanism, switch 54, etc. are similar to those shown in FIGS. 22 and 23, and are made of the same components. are given the same reference numerals, so it will be easier to understand if you refer to them.

In the figure, the solid line indicates the stereo photography mode, and the broken line indicates the normal photography mode. In the stereo photography mode, the optical path compensation plate 3X is retracted from the photographing optical path and the filters 3a and 3b are inserted into the photographing optical path. and,
The protrusion 73 closes the switch s4. In normal photo mode.

While the filters 3a and 3b are retracted from the photographing optical path,
An optical path compensation plate 3x is inserted into the photographing optical path.

At this time, since the protrusion 73 also rotates together with the light flux limiting plate 3, the switch S4 is opened.

In this way, since the photographing optical path length is the same in either the stereo photography mode or the normal photography mode, optical path length correction in the stereo photography mode becomes unnecessary.

In the case of the embodiment shown in FIG. 25, the light flux limiting plate 3 is retracted from the photographing optical path each time photographing is completed (for example,
The process may be performed between steps P13 and PI3). At this time.

Step P4 may be deleted, and when it is determined in step P2 that the mode is not stereo photography mode, step P3 may be skipped and the process may proceed to step P5.

[Detection of camera posture]

The first and second light beams on the light flux limiting plate 3 provided in the camera of the present invention.
The image of the subject photographed with the camera in a state where the filters 3a and 3b are arranged on the left and right sides of the optical axis (this will be called the horizontal position) has a parallax that allows for appropriate stereoscopic viewing. Because it is recorded on the film surface as a double image,
When viewing images using viewing glasses, you can enjoy images with a three-dimensional effect. However, when the camera is rotated from the horizontal position to the optical axis (for example, to a vertical position rotated 90 degrees around the optical axis), the first and second filters 3a
, 3b are arranged above and below the optical axis, so the field image photographed in this state is not recorded on the film surface as a double image with left and right parallax that allows stereoscopic vision. That is.

Even if you use glasses, you cannot see the image with a three-dimensional effect.

To deal with this problem, the camera is equipped with an attitude detection sensor, which detects the rotation angle of the camera from the horizontal position, and displays a warning when the camera is rotated by a predetermined angle or more.

FIG. 28 shows an example of a posture detection sensor, in which a fan-shaped plate 81 is provided with a rotating shaft 83 at a key part, and a weight 84 is provided at one end of an arm 82 extending on the opposite side of the sector-shaped plate 81. . Further, an angle detection encoder 85 and a photoelectric attitude detection sensor 86 for detecting .xi. turns of the angle detection encoder 85 are arranged on the fan-shaped plate 81. Since the arm 82 occupies the vertical direction due to the action of the weight 84 even when the posture of the camera changes, the sensor 86 provided on the camera body side outputs a rotation angle signal from the horizontal position of the camera. When the camera rotates around the optical axis and the output signal from the sensor 86 exceeds a predetermined value range, 1. By means not shown, for example, the LED in the viewfinder is turned on, or the stereo mode display (described later) is blinked. 5) Alert the person by means such as nuisance or sounding a buzzer, etc.5 to notify that appropriate stereoscopic vision cannot be obtained. Note that the attitude detection sensor can be provided at any position of the camera. Furthermore, a mercury switch may be used as the attitude detection sensor. Furthermore, the warning may be issued only when the switch S is ON, that is, when the filter is inserted into the optical path, or regardless of the position of the filter (ON-OFF of the switch S4). , it may be possible to always do so.

Furthermore, in order to always be able to take photographs that provide stereoscopic vision regardless of the orientation of the camera, the first and second filters may be rotated in accordance with the orientation of the camera. Figures 29 and 30 show the filter rotating mechanism for this purpose. Figure 29 is an enlarged sectional view of the vicinity of the light flux limiting plate 3', Figure 30 is an enlarged front view, and Figures 22 and 30 are A filter rotation mechanism is added to the configuration shown in FIG. 23 in which a light flux limiting plate is inserted into and retracted from the optical path of a photographing lens. First and second filters 3a
, 3b are attached, and the peripheral edge of the filter disk 3p is formed with a tooth shape, forming a gear portion 3r. The filter disk 3p is rotatably supported by a frame 3s, and a sector gear 92 is provided on an extension of the frame to constitute a light flux limiting plate 3'. The peripheral gear portion 3r of the filter disk 3p is configured to mesh with a gear 93 provided on the shaft of a drive motor 95 to rotate the filter disk 3p. The light flux limiting plate 3' is connected to the drive motor 9.
22 and 23 that the lens is inserted into the photographing optical path and withdrawn from the photographing optical path by the gear 91 and sector gear 92 driven by the lens 4.

Note that 93 is a projection provided on the light flux limiting plate 3'.

When the light flux limiting plate 3' is inserted into the photographing optical path, a switch S4 for detecting this is closed.

Now, when a signal indicating the attitude of the camera is input from the attitude sensor 86 that detects the attitude of the camera to a control means (not shown), the control means determines the rotation angle of the filter according to the attitude of the camera, and sends a signal to the motor 95. is output and the filter disk 3p is rotated to set the first and second filters at positions where stereoscopic viewing is possible. As the control means, a microprocessor used for camera focus adjustment, exposure control, etc. can be used.

In addition to the above, the filter disk may be rotated manually, or an arm with a weight may be provided on the filter disk.
It is also possible to use gravity so that the first and second filters are always arranged on the left and right sides of the optical axis.

[Display/record shooting mode]

The stereo camera implementing the present invention has two shooting modes, a stereoscopic photo mode and a normal photo mode, and can be switched at will, so the currently set shooting mode is displayed in the viewfinder, etc. However, it is also desirable to provide means for displaying and recording the photographing mode, such as by imprinting it on the film surface. For this reason.

It is preferable to provide a switch that turns on when the light flux limiting plate is inserted into the photographing optical path, and also to provide a photographing mode display element in the viewfinder, so that when the switch is turned on, the display element lights up to indicate the photographing mode. Further, as shown in FIG. 24, it is preferable that a photographing mode imprinting device 67 is provided on the back cover of the camera, and the photographing mode is imprinted on the film surface by activating the imprinting device 67 when the switch is turned on. For example, in the stereophotography mode, as shown in FIG. 8, a symbol "S" indicating that it is a stereophotography may be imprinted on the screen.

In this way, it can be easily recognized that the photograph is a stereoscopic photograph.

Although the embodiments described above are directed to negative color films, they may also be directed to visual color films, or may be applied to electronic still cameras.

〔Effect of the invention〕

As explained above, the stereo camera of the present invention has two shooting modes, and by switching the shooting mode, it is possible to take a stereo photo and a normal photo, and when the stereoscopic photo mode is selected, the optical path of the shooting lens The optical path length will be longer than in the normal photo mode because the filter is inserted into the camera, but the optical path length can be changed by changing the amount of extension of the photographic lens, or by inserting a transparent compensator with the same optical path length as the filter from within the optical path. Since compensation is provided by inserting the lens when it is retracted, it is possible to take a photograph in focus in both the stereoscopic photography mode and the normal photography mode.

Fig. 1 is an explanatory diagram of the basic configuration of a stereo camera, Fig. 2 is an explanatory diagram of the spectral transmission characteristics of a wavelength selective transmission filter, Fig. 3 is an explanatory diagram of the photographing optical system, and Fig. 4 is an explanatory diagram of the spectral transmission characteristics of the wavelength selective transmission filter. FIG. 8 is an explanatory diagram of a photographed object scene image, and FIG. 9 is a diagram illustrating color shift of a point image.

Fig. 10 is a front view showing the configuration of the light flux limiting plate, Fig. 11 is a front view showing the wavelength selective transmission filter and the shape of the aperture blades, and Figs. 12 to 15 show the wavelength selective transmission filter on the light flux limiting plate. A front view showing the shape, FIG. 16 is a diagram showing the configuration of a focus plate of a single-lens reflex camera, FIG. 17 is an explanatory diagram of a stereo camera's diaphragm/shutter mechanism, FIG. 18 is a front view of the shutter blade, and FIG. 19 is an explanatory diagram of temporal changes in the exposure aperture due to the diaphragm-shutter mechanism.

Fig. 20 is a diagram showing the relationship between shutter speed and aperture value with respect to exposure value, Fig. 21 is a plan sectional view of the stereo camera, Fig. 22 is a plan view showing the insertion and retraction mechanism of the light flux limiting plate,
3 is a front view, FIG. 24 is a block diagram of the camera control circuit, FIGS. 25 and 26 are flowcharts showing the sequence of camera control, and FIG. 27 is the configuration of a light flux limiting plate having an optical path length compensating plate. FIG. 28 is a front view of the attitude detection sensor, and FIG. 29 is a plan view showing the insertion and retraction mechanism of a light flux limiting plate equipped with a filter disc rotation mechanism.

FIG. 30 is a front view as well.

l: photographic lens, 2: aperture, 3: light flux limiting plate, 3a: first filter, 3b: second filter, 4: film, 60
: Microcomputer, 85: Angle detection encoder, 86: Posture detection sensor.

λ+C daytime) No. figure No. figure No. figure evening figure (a) Condolence figure No. figure broom figure No. figure t (,1ri (b) No. figure No. figure No. figure No. figure No. Ward (a) (b) broom figure No. figure father oO m--1-on 4V series I ( No. figure No. four figure No. figure X Condolence figure Condolence figure No. four figure No. engineering figure

Claims (3)

[Claims] (1) A first filter is placed in the optical path of the photographic lens on the left side with respect to the optical axis, and a second filter having spectral transmission characteristics different from that of the first filter is placed on the right side with respect to the optical axis. Insertion of the first and second filters into the optical path in a stereo camera equipped with a switching means capable of switching between a stereoscopic photography mode in which the first and second filters are removed from the optical path and a normal photography mode in which the first and second filters are retracted from the optical path. A stereo camera characterized by comprising compensation means for compensating for changes in optical path length caused by evacuation. (2) The stereo camera according to claim 1, further comprising an automatic focus adjustment device that advances the photographing lens according to the subject distance, and the compensation means according to the insertion and retraction of the first and second filters into the optical path. A stereo camera characterized in that an automatic focus adjustment device is controlled to compensate for changes in optical path length by changing the amount of extension of a photographing lens. (3) In the stereo camera according to claim 1, the compensating means includes a transparent compensating plate having an optical path length equivalent to that of the first and second filters, and when the first and second filters are retracted from the optical path. A stereo camera characterized in that the transparent compensating plate is inserted into an optical path to compensate for changes in optical path length.