JPH07209699A - Camera with binocular finder - Google Patents

Abstract

PURPOSE:To provide a camera with a binocular finder having a finder easy to view even in the case image plane size is small and having form by which excellent holding performance is obtained in a single lens reflex camera. CONSTITUTION:As to this camera with a binocular finder; a binocular observing optical system constituted of a photographing lens 2 condensing the optical image of a subject 1, a mirror 3 reflecting the optical image, a screen 4 where the reflected optical image is formed as a subject image reversed right and left, and the binocular observing optical system 5 which is set above the screen 4, whose center part is separated to two overlapped observation visual fields and by which a synthetic image 13 is formed from the visual fields of both eyes by making an observer observe with both eyes, is mounted on its upper part. Then, film smaller than existing film is used and a photographing lens system and format size are made small in size in the camera.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera having a binocular viewfinder for observing a subject image formed by a lens for photography.

[0002]

2. Description of the Related Art A general single-lens reflex camera reflects a subject light that has passed through a lens for photography by a mirror,
A subject image was formed on the screen, and the image was observed with a single finder through a pentaprism.

That is, the viewfinder can be observed only by either the right eye or the left eye.
There is also one in which an interchangeable finder called a "sport finder" is exchanged and an enlarged screen image is observed with both eyes at a position away from the camera.

However, there has been no single-lens reflex camera having a viewfinder (hereinafter referred to as a binocular viewfinder) which can be observed by both eyes without separating from the camera like binoculars. On the other hand, JP-A-5-165166 and JP-A-5-165166
In JP 142641, the width of the film is 20 which is narrower than the current film for photography (35 mm width).
Small films of mm to 30 mm have been proposed. Further, in Japanese Patent Laid-Open No. 5-142641, the shooting screen size is smaller than the current shooting size (so-called 135 type; vertical 24 mm, horizontal 36 mm), vertical 16.6 mm,
A size of 29.7 mm in width is proposed. By reducing the width and shooting size of these films,
It also states that the camera can be made smaller.

[0005]

However, in the above-mentioned current single-lens reflex camera using the film having the width of 35 mm, the width of the film (height of the cartridge case) is used as a reference, so that the observation optical system other than the pentaprism is used. If you use, the camera becomes larger. Therefore, the shape of the single-lens reflex camera was basically unchanged.

On the other hand, even if the size of the camera can be reduced by adopting a small film having a small width and a small screen size, if the pentaprism is also downsized, the screen of the finder observed by the photographer also becomes small. Occur.

Further, if the size of the camera is reduced in the current configuration, the viewfinder and the grip are too close to each other, the holding property is deteriorated, and the hand is obstructed and it becomes difficult to look through. As described above, if the configuration of the current single-lens reflex camera is made small as it is, an adverse effect occurs.

[0008] In particular, when looking through the viewfinder for a long time such as telephoto photography, it is desirable that both eyes can be used for observation.
No single-lens reflex camera having such a form has been proposed. Further, in the case of macro photography, the focus is adjusted so that the aerial image of the subject overlaps the index (such as a crosshair) on the transmissive screen. Therefore, in the conventional macro photography, the eyes were swung to the left and right in the field of view of the finder for confirmation, but if the eyes can be seen with both eyes, focusing becomes easy.

Therefore, an object of the present invention is to provide a single-lens reflex camera having a binocular viewfinder which has a viewfinder that is easy to see even when the screen size is small and has a good holding property.

[0010]

In order to achieve the above object, the present invention provides a single photographing lens for forming a subject image, and the above-mentioned subject image formed by this photographing lens. A camera with a binocular viewfinder, which is composed of a view field for left-eye observation and a view field for right-eye observation that have a common observation area, and a viewfinder optical system that enables independent observation of the separated left and right subject images provide. Further, there is provided a camera with a binocular viewfinder in which a small-sized patrone for taking a photograph is arranged under at least a part of the viewfinder optical system. .

[0011]

In the camera with a binocular finder having the above-described structure, the optical image of the subject is condensed by the photographing lens in the finder optical system, passes through it, and is then reflected by the mirror to produce an image in which the left and right are inverted on the screen. It is imaged. The binocular observation optical system installed above the screen separates the formed image into two overlapping observation fields at the center of the screen, as seen by the left and right eyes of the photographer, and allows the two eyes to see them. To form a composite image.

Further, the holding part of the camera is downsized by mounting the binocular observation optical system on the upper part and using a film smaller than the existing film to downsize the taking lens system and the format size.

[0013]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 shows and describes a basic configuration of a camera with a binocular viewfinder according to the present invention. In the observation optical system of the camera with the binocular viewfinder, the optical image of the subject 1 is condensed by the taking lens 2 and passes through it, then reflected by the mirror 3 and imaged on the screen 4.

That is, a left-right inverted subject image is formed on the screen 4. The binocular observation optical system 5 provided above the screen 4 forms the observation fields of view of the left and right eyes on the screen 4, but since the left and right are reversed, the observation field of view of the right eye is the left side of the screen 4. In addition, the observation field of view for the left eye is formed on the right side of the screen 4. The left and right observation fields of view overlap in the central portion of the screen 4. Therefore, with the right eye alone, the image 11
However, although the image 10 is visible with the left eye alone, the composite image 13 is visible with both eyes.

Next, a binocular observation optical system of a camera with a binocular viewfinder according to the first embodiment of the present invention will be described. FIG. 2 shows the configuration of a binocular observation optical system of the camera with a binocular viewfinder, and FIG. 3 shows an optical path diagram as seen from the rear of the camera.

In such a structure, the subject image that has passed through the taking lens 2 is reflected by the mirror 3 and forms an image on the screen 4. An image in which the right and left of the subject image is reversed is formed on the screen 4. This mirror 3 is a movable mirror and descends as shown in FIG. 2 at the time of observation.
At the time of shooting, it rotates 45 degrees so as to move to the raised position.
Display members 21 and 22 are provided on the left and right of the screen 4.

The image on the left side of the screen 4 (right side of the subject) enters from the bottom surface of the roof prism 13, is reflected by the roof on the left slope, is reflected by the incident surface, and is emitted from the roof on the right slope. It Here, near the apex angle of the roof portion of the prism 13 (the portion where the light incident from the screen is first reflected) is subjected to a reflection treatment such as mirror coating, and the vicinity of the bottom surface of the roof portion (the light reflected on the bottom surface is (The part to eject)
Is transparent.

The emitted light is reflected inside the prism 14 three times and enters the prism 16. In the prism 14, the light is first reflected by the concave reflection surface 20, reflected twice by the inclined surface portion, and then emitted from the concave lens surface 19. Therefore, the subject image is reduced and guided to the prism 16.

The prism 16 reflects the light twice and emits it to the observation portion of the right eye. In the prism 16, the first inclined reflecting surface is bent downward, and the second inclined reflecting surface is bent backward (observation method). The exit surface of the prism 16 is a convex lens, and the subject image reduced by the prism 14 is enlarged. Therefore, a large subject image can be observed.

Although not shown, the image on the right side of the screen 4 (the left side of the subject) is reflected by the prism 15 and the prism 17 in the same manner as described above, and is emitted to the observation unit for the left eye. Further, in the prism 13, the right side observation light beam and the left side observation light beam intersect and are emitted to the opposite side.

Here, the observation light flux for the right eye and the observation light flux for the left eye are reduced and emitted from the prism 13, and the subject image at the center of the screen enters both the visual field of the right eye and the visual field of the left eye. However, part of the left and right fields of view overlap.

Therefore, when observed with both eyes, it can be recognized as one screen. Also, screen 4
The displays placed on both sides of can be observed well. Here, since the binocular observation optical system has a thin shape that spreads in the left-right direction on the upper portion of the screen 4, batteries and films can be arranged as shown in FIG. In FIG. 3, the battery 27 is arranged below the prism 17, the cartridge 23 is arranged below the prism 15, the shutter control member 26 is arranged below the prism 14, and the spool chamber 25 is arranged below the prism 16. In particular, if you use a small film or a small cartridge, the height of the camera will be even lower and the shape of the holding can be improved.

The concave reflecting portion 20 provided on the prism 14
And concave lens 19 and convex lens 18 provided on prism 16.
May not be integrated with the prism, but may be composed of another optical member. Further, a condenser lens may be inserted between the screen 4 and the prism 13.

Next, a binocular observation optical system of a camera with a binocular finder as a second embodiment according to the present invention will be described. FIG. 4 shows the configuration of the binocular observation optical system viewed from above the camera, and FIG. 5 is a diagram showing the optical path thereof. here,
The prism 13, the prism 14, and the prism 15 are the same as those in the first embodiment, and are arranged in a state rotated by 90 degrees as compared with the first embodiment. A subject image formed on the screen 4 by a photographing lens system (not shown) is reflected by the mirror 28 and then enters the prism 13.

The observation light beam for the right eye emitted laterally from the prism 14 is reflected backward by the mirror 29, passes through the eyepiece lens 31, and is observed by the right eye. Also,
The observation light flux for the left eye is reflected by the mirror 30, passes through the eyepiece lens 32, and is observed by the left eye. The prisms 13 and 1
Since the height of 4, 15 is low, even if they are arranged in this way, they do not project in the front direction of the camera. Furthermore, screen 4
Since the interval between the prisms 13 is long, the observation light flux is widened, and the overlap between the left and right visual fields at the center of the screen is increased. Therefore, when observed with both eyes, the observation becomes easier than in the first embodiment.

In the embodiment shown in FIG. 5, the arrangement of the battery 27, the cartridge 23, the shutter controller 26, and the spool chamber 25 is also shown. The eyepieces 31 and 32 have a battery 27.
Alternatively, it may be placed on the spool chamber. In particular, since the eyepiece lens can be provided at any position in the front-back direction, the eyepiece lens can be made larger to further enlarge the subject image, and a diopter adjustment mechanism can be provided.

Next, a binocular observation optical system of a camera with a binocular finder as a third embodiment according to the present invention will be described. FIG. 6 shows the configuration of the binocular observation optical system, and FIG. 7 is a diagram showing its optical path.

In the conventional pentaprism, the third reflecting surface (slope facing the eyepiece) is a reflecting surface, and that portion is used as a transmitting surface, and the roof prism 34 or the roof prism 35 is arranged there. ing. The subject light imaged on the screen 4 is horizontally reversed at the roof portion of the roof prism 33, and the observation light flux for the right eye is emitted from the prism 34 and the observation light flux for the left eye is emitted from the prism 35.

Further, the light emitted from the prism 34 or 35 is observed through the concave lens 36 or 37 and the convex lens 38 or 39. Therefore, the subject light is reduced, passes through the prism, and is enlarged and observed. In such an optical system, the left and right observation light beams are emitted obliquely rearward, but there is an advantage that a conventional penta prism can be used. Further, by setting the reflectance of the third reflecting surface to be capable of both reflection and transmission, it is possible to provide the same monocular finder as the conventional one and use it together.

Next, FIG. 8 shows an external configuration of a camera with a binocular viewfinder as a fourth embodiment according to the present invention. This camera is a camera equipped with the binocular observation optical system shown in the first to third embodiments. The binocular finder-equipped camera of the fourth embodiment is a camera equipped with the binocular observation optical system of the second embodiment.

In this camera with a binocular viewfinder, the taking lens barrel 40 is fixed to the camera body 41 or detachable. The camera body 41 is provided with a release button 43 and a zoom button 44 at positions where it can be operated with the finger of the right hand. Further, the viewfinders 45 and 46 have a mechanism that can be adjusted left and right according to the eye width (the distance between the eyes of the photographer).

A mirror 29 or 30 and an eyepiece lens 31 or 32 are arranged in the viewfinder, and the eye width can be adjusted by moving the viewfinder in parallel. Further, an adjusting lever 47 for adjusting the diopter by moving the eyepiece is also provided.

Here, the taking lens is detachable, and an interchangeable lens for a single lens reflex currently used can be used. Technically, this replacement can be easily realized by making the positions, shapes of the mount, the signal contacts, the flange back, etc., equal to those of the existing camera. However, the use of a small film having a narrow width and a small shooting size has an advantage of further miniaturization, as compared with the use of the current film (35 mm film).

FIG. 9 shows a new format size for the current film format (24 mm long, 36 mm wide) for the image circle of the current interchangeable lens.

This is because the camera is downsized due to the use of a small film, and the new format size (for example, 16.6 mm in length, 29.7 mm in width) is placed at the bottom so that the camera falls within the image circle of the lens. The screen can be shifted.

FIG. 10A is a diagram showing an example of a current single-lens reflex camera using a current film as seen from the side, and FIG. 10B is a current interchangeable lens (see FIG. 10).
It is the figure which looked at the camera of the present invention which used the film of the new format size (the same lens as (a)) from the side.

In FIG. 10B, the position of the film is shifted so that the center of the photographing screen is located below the optical axis of the lens. Therefore, the optical system for binocular observation is almost the same as the height (diameter) of the lens barrel, which is good in terms of design.

Further, it is possible to shift the optical axis of the lens from the center of the photographic screen in this way also in another observation optical system (for example, a monocular finder using the same pentaprism as in the prior art).

Next, FIG. 11 shows an external configuration of a camera with a binocular viewfinder in which an interchangeable taking lens as a fifth embodiment of the present invention can be used. FIG. 11 (a)
[FIG. 6] is a view of a camera with a replaceable lens equipped with the binocular observation optical system shown in the first to third embodiments, which is viewed obliquely from the front. A lens mount 50 for attaching and detaching the lens is provided on the front surface of the camera, and a plurality of contacts 51 for communicating with the lens are provided inside the mount. It goes without saying that these lens mounts and contacts may be adapted to the existing interchangeable lenses so that the existing lenses can also be used.

FIG. 11B is an external view of a camera using the current interchangeable lens and the film of the new format size as seen from the front. The camera shown in FIG. 11B is similar to that shown in FIG. 10B in that the center of the photographing screen is shifted downward from the optical axis of the lens. Therefore, the mirror 3 is also displaced downward.

FIG. 11C is an external view of a configuration example of an interchangeable lens that can be commonly used in the current single-lens reflex camera and the camera with the binocular viewfinder according to the present embodiment.
Inside the interchangeable lens, a contact point 53 is provided so as to come into contact with the contact point 51 on the mount side when mounted on the lens mount 50 of the camera shown in FIG. 11B.

As described above, in the camera with the binocular viewfinder according to the present embodiment, the left and right visual fields are combined and viewed from the two viewfinders, so that it is easy to see even if the screen becomes small. In particular, by providing the left and right independent observation optical systems, each observation light beam can be narrowed and the observation optical system can be configured with a small optical member.

Further, since it is possible to observe with both eyes without taking an eye off from the viewfinder of the camera, it is possible to obtain good holding without tiredness even when observed for a long time. Also during macro shooting,
The aerial image of the subject and the index of the screen (such as crosshairs) can be easily overlapped, and focusing can be facilitated.

In particular, when an existing interchangeable lens for a single-lens reflex camera can be used and a "new format film" having a small width and screen size is used, a "lens-compatible compact binocular viewfinder camera" can be provided.

Further, the following construction of the camera with the binocular viewfinder can be obtained from the embodiment described above. (1) A single lens for forming a subject image, and the subject image formed by this lens are separated into a left-eye observation visual field and a right-eye observation visual field having a common observation region, A camera with a binocular viewfinder that is composed of a viewfinder optical system that allows the left and right separated subject images to be viewed independently by both eyes.

(2) The camera with a binocular viewfinder according to (1), wherein the lens is a photographic lens. (3) The camera with a binocular viewfinder according to (2), wherein the photographing lens is a lens for forming a subject image on a silver salt film.

(4) The camera with a binocular viewfinder according to the above (3), characterized in that a cartridge for loading a film for photographing is arranged under at least a part of the finder optical system.

(5) The camera with a binocular finder according to (1) or (4) above, which uses a smaller cartridge than the one in which a 35 mm film is loaded in the cartridge. (6) The camera has a mirror for reflecting the light flux that has passed through the photographing lens and a screen for forming a horizontally-reversed subject image reflected by the mirror (2) to (5). ) The camera with the binocular viewfinder described above.

(7) The camera with a binocular viewfinder according to (6), wherein the finder optical system has an optical system for horizontally inverting and horizontally separating the subject image formed on the screen.

(8) The camera with a binocular viewfinder according to any one of (1) to (7), wherein the lens is a removable interchangeable lens. (9) The interchangeable lens camera and (1) to (8)
Camera with binocular viewfinder described.

(10) In a camera to which an interchangeable lens for a single-lens reflex camera using a film having a first width can be mounted and which uses a film having a second width which is narrower than the first width, the camera has a photographing screen. A camera with a binocular viewfinder, wherein a film for photography is arranged so that its center is below the center of the optical axis of the interchangeable lens.

(11) The interchangeable lens type camera described in (10) above, wherein an observation optical system for observing a subject image is arranged on the photographic film. (12) The camera according to (11), wherein the observation optical system is a binocular viewfinder having optical systems for left-eye observation and right-eye observation.

(13) In an optical device for observing an image which is formed on the screen in the left-right direction in a reversed manner in the normal direction, the image formed on the screen is observed by the left eye having a common observation area. A binocular finder characterized by having an optical system that separates the visual field for observation and the visual field for right-eye observation, and allows the separated left and right images to be independently observed by both eyes, and observes the above images with both eyes. With camera.

(14) In an optical device for observing an image formed by reversing left and right on a screen by inverting it in a normal direction, a roof prism having left and right inclined surfaces is arranged behind the screen, and The roof prism emits light on the right side of the image on the screen from the left side of the prism, emits light on the left side of the image from the right side of the prism, and the light emitted from the roof prism. A binocular viewfinder that is equipped with an eyepiece optical system to observe light with the left and right eyes and observes the image with both eyes.

(15) The binocular viewfinder according to the above (13) or (14), wherein the screen is formed by the light passing through the taking lens of the camera. (16) In the roof-type prism, the image at the center of the screen is emitted to both left and right sides, and the left and right observation fields of view overlap at the center of the screen.
The binocular viewfinder according to 5).

(17) A combination of the binocular viewfinder described in (13) to (16) and the camera described in (1) to (12). Although the embodiments of the present invention have been described on the premise that a silver salt film is used, an image pickup device such as a CCD or a MOS can be used instead of the silver salt film.

[0057]

As described in detail above, according to the present invention, in the single-lens reflex camera, the image formed by the photographing lens is used as a visual field for the left eye observation so that the observation areas partially overlap each other. By dividing the right-eye observation field of view and observing the separated left and right images with both eyes, it has a viewfinder that is easy to see even when the screen size is reduced. Further, by using a cartridge in which a small film is loaded, it is possible to provide a camera having a shape capable of downsizing the photographing lens system and obtaining good holding property.

[Brief description of drawings]

FIG. 1 is a diagram showing a basic configuration of a camera with a binocular viewfinder according to the present invention.

FIG. 2 is a diagram showing a configuration example of a binocular observation optical system of a camera with a binocular finder as a first embodiment according to the present invention.

FIG. 3 is a diagram showing an optical path of the binocular observation optical system shown in FIG. 2 as viewed from the rear of the camera.

FIG. 4 is a diagram showing a configuration example of a binocular observation optical system of a camera with a binocular finder as a second embodiment according to the present invention.

5 is a diagram showing an optical path seen from above of a camera of the binocular observation optical system shown in FIG.

FIG. 6 is a diagram showing a configuration example of a binocular observation optical system of a camera with a binocular finder as a third embodiment according to the present invention.

7 is a diagram showing an optical path of the binocular observation optical system shown in FIG. 6 as viewed from the rear of the camera.

FIG. 8 is a diagram showing an external configuration of a camera with a binocular finder as a fourth embodiment according to the present invention.

FIG. 9 is a diagram showing a new format size with respect to a current film format for an image circle of a current interchangeable lens.

FIG. 10 (a) is a diagram showing an example of a configuration of a current single-lens reflex camera using a current film as viewed from the side, and FIG. 10 (b) shows a current interchangeable lens and a film of a new format size. It is the figure which looked at the camera of the present invention used from the side.

FIG. 11 is a diagram showing appearances and configurations of a camera with a binocular viewfinder and an interchangeable lens that can use an interchangeable taking lens according to a fifth embodiment of the present invention.

[Explanation of symbols]

1 ... Subject, 2 ... Photographing lens, 3 ... Mirror, 4 ... Screen, 5 ... Binocular observation optical system, 6 ... Left eye, 7 ... Right eye, 8 ...
Right eye view, 9 ... Left eye view, 10, 11 ... Image, 12 ... Composite image, 13 ... Roof prism, 14, 15, 16, 17 ...
Prism, 18 ... Convex lens, 19 ... Concave lens surface, 20 ...
Concave reflection surface 21, 22 ... display member, 23 ... patrone,
24 ... Film, 25 ... Spool chamber, 26 ... Shutter control member, 27 ... Battery.

Claims (2)

[Claims] 1. A single photographing lens for forming a subject image, and the subject image formed by the photographing lens,
And a viewfinder optical system that separates a left-eye viewing field and a right-eye viewing field having a common viewing region into each of which the left and right object images can be independently viewed by both eyes. Camera with binocular viewfinder. 2. The camera with a binocular viewfinder according to claim 1, wherein a small-sized patrone for taking a photograph is arranged under at least a part of the finder optical system.